Patent Publication Number: US-2023151805-A1

Title: Pump and air supply device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority to Japanese Patent Application No. 2020-064594 (entitled “PUMP AND AIR SUPPLY DEVICE”) filed on Mar. 31, 2020. The entire contents of the above-listed application are hereby incorporated by reference for all purposes. 
     TECHNICAL FIELD 
     The present invention relates to a pump and an air supply device using a vibration actuator. 
     BACKGROUND 
     Conventionally, there has been known a small pump using a rotary motor as shown in patent document 1, a pump utilizing resonance of a motor as shown in patent document 2, a pump using a piezoelectric element or the like as a pump used for a sphygmomanometer or the like. 
     In the small pump of the patent document 1, a plurality of diaphragms forming a pump chamber are provided in a case, a suction valve is provided in the pump chamber and a cylindrical discharge valve body is formed at a center portion of the pump chamber. The plurality of diaphragms are connected to a swinging body which can be swung by rotation of an eccentric rotation shaft and thus the diaphragms can move up and down when the swinging body swings. The eccentric rotation shaft is eccentrically fixed to a disk portion fixed to a rotation shaft of a DC motor disposed below the eccentric rotation shaft. This pump uses the eccentric rotation shaft and the swinging body to convert normal rotation of the DC motor around the rotation shaft thereof into precession movement for moving the diaphragms up and down. 
     Further, the pump of the patent document 2 is a reciprocating motor having a cylindrical shape. Each of a fixed portion and a movable portion of this reciprocating motor has a magnet and the pump device is driven by utilizing a resonance phenomenon to achieve air suction and air discharge. Furthermore, in the pump using the piezoelectric element, a diaphragm is reciprocated by the piezoelectric element to repeat air suction and air discharge through valves for switching between the air suction and the air discharge. 
     RELATED ART DOCUMENTS 
     Patent Documents 
     Patent document 1: JP 2002-106471A 
     Patent document 2: JP 2019-75966A 
     SUMMARY 
     Problems to be Solved by the Invention 
     In this regard, there are needs of utilizing any one of the above-described pumps in a routinely-used device such as a sphygmomanometer. Thus, a high-performance pump which has a thinner thickness and can increase a flow rate and pressure of the air has been needed. 
     However, it is easy to increase output power of the rotary motor used in the pump of the patent document 1, whereas there is a problem that a magnetic efficiency of the rotary motor deteriorates due to its structure restriction if a thickness of the rotary motor is reduced and thus characteristics of the rotary motor significantly deteriorates. Further, the pump of the patent document 2 has a problem that it is difficult to reduce a thickness of the pump because the pump has a cylindrical shape. 
     Further, it is easy to reduce a size of the pump using the piezoelectric element, whereas there is a problem that a vibration displacement amount of the piezoelectric element is small and pressure characteristics or flow characteristics of the pump are limited, and thereby it is very difficult to achieve both of a desired pressure and a desired flow rate. 
     The present invention has been made in view of the above-described conventional problems. Accordingly, it is an object of the present invention to provide a high-performance pump whose thickness can be reduced and which can secure a high discharge pressure and a large transfer flow rate and an air supply device including the high-performance pump. 
     Means for Solving the Problems 
     This object is achieved by the present inventions as defined in the following (1) to (13). 
     (1) A pump, comprising: 
     a vibration actuator which can be electromagnetically driven; and 
     a pump unit for suctioning and discharging fluid due to electromagnetic drive of the vibration actuator, 
     wherein the vibration actuator includes: 
     a fixed body on which the pump unit is provided, the fixed body containing one of a coil core portion having a coil and a core portion around which the coil is wound and a magnet disposed so as to face an end portion of the core portion, 
     a movable body elastically held by magnetic attraction force of the magnet, the movable body containing another one of the coil core portion and the magnet, and 
     a shaft portion for supporting the movable body so that the movable body can perform reciprocating rotation, 
     wherein the pump unit includes: 
     a movable wall which can be moved by rotational movement of the movable body, and 
     a sealed chamber which is communicated with a discharge port for the fluid and a suction port for the fluid and whose volume can be changed by displacement of the movable wall, 
     wherein the movable body has a pressing portion which can be moved in an arc track around the shaft portion and abut against the movable wall to press the movable wall when the movable body performs the reciprocating rotation, and 
     wherein the movable wall is disposed in a moving direction of the pressing portion and displaced when the movable wall is pressed by the pressing portion to discharge the fluid in the sealed chamber through the discharge port. 
     (2) The pump according to the above (1), wherein the movable body is provided so as to extend in a direction perpendicular to an axial direction of the shaft portion from a portion axially supported by the shaft portion so that the movable body can perform the reciprocating rotation and has an arm portion, 
     wherein the other one of the coil core portion and the magnet is provided on an end portion of the arm portion, 
     wherein the sealed chamber contains a pair of sealed chambers, 
     wherein the pair of sealed chambers are disposed so as to face each other at position sandwiching the arm portion in a reciprocating rotation direction of the arm portion, 
     wherein the movable wall contains a pair of movable walls, 
     wherein the pressing portion has a pair of pushers respectively corresponding to the pair of movable walls, and 
     wherein each of the movable walls of the sealed chamber is pressed by the pusher when the arm portion performs reciprocating rotation. 
     (3) The pump according to the above (1), wherein the movable body has a center portion axially supported by the shaft portion so that the movable body can perform the reciprocating rotation, and a pair of arm portions respectively extending in opposite directions perpendicular to an axial direction of the shaft portion from the center portion, 
     wherein the other one of the coil core portion and the magnet is provided on an end portion of each of the arm portions, and 
     wherein the one of the coil core portion and the magnet is provided on the fixed body so as to face the other one of the coil core portion and the magnet, 
     wherein the sealed chamber contains a pair of sealed chambers, 
     wherein the pair of sealed chambers are disposed side by side along an extending direction of the pair of arm portions, 
     wherein the movable wall contains a pair of movable walls, 
     wherein the pressing portion has a pair of pushers respectively corresponding to the pair of movable walls, and 
     wherein each of the movable walls of the sealed chamber is pressed by the pusher when the arm portions perform reciprocating rotation. 
     (4) The pump according to the above (3), wherein the discharge ports of the pair of sealed chambers are connected to each other. 
     (5) The pump according to any one of the above (2) to (4), wherein the pushers are respectively connected to the movable walls. 
     (6) The pump according to any one of the above (1) to (5), wherein the magnet is provided on one of the movable body and the fixed body and forms a magnetic spring together with the core portion of the coil core portion provided on another one of the movable body and the fixed body. 
     (7) The pump according to any one of the above (1) to (6), wherein the magnet is magnetized so as to have three magnetic poles, and 
     wherein the coil is wound around the core portion of the coil core portion and the core portion of the coil core portion has two magnetic poles facing the magnet in a magnetization direction of the magnet. 
     (8) The pump according to any one of the above (1) to (6), wherein the magnet is magnetized so as to have four magnetic poles, and 
     wherein the coil is wound around the core portion of the coil core portion and the core portion of the coil core portion has three magnetic poles facing the magnet in a magnetization direction of the magnet. 
     (9) The pump according to any one of the above (1) to (6), wherein the magnet is magnetized so as to have four magnetic poles, and 
     wherein three coils are would around the core portion of the coil core portion and the core portion of the coil core portion has three magnetic poles facing the magnet in a magnetization direction of the magnet. 
     (10) The pump according to any one of the above (1) to (6), wherein the movable body has one end portion axially supported by the shaft portion so that the movable body can perform the reciprocating rotation and another end portion on which the other one of the coil core portion and the magnet is provided, 
     wherein the fixed body has the one of the coil core portion and the magnet which faces the other one of the coil core portion and the magnet in a direction perpendicular to a rotational axis of the movable body, and 
     wherein the magnet is magnetized so as to have two magnetic poles. 
     (11) The pump according to the above (10), wherein the core portion has three magnetic poles around which the coil is wound. 
     (12) The pump according to the above (1) or (2), wherein the movable body has one end portion axially supported by the shaft portion so that the movable body can perform the reciprocating rotation and further contains the coil core portion, and 
     wherein the fixed body contains the magnet facing the coil core portion in a direction perpendicular to a rotational axis of the movable body. 
     (13) An air supply device, comprising: the pump defined by any one of the above (1) to (12). 
     Effects of the Invention 
     According to the present invention, it is possible to provide a pump which has a thinner thickness and can secure a high discharge pressure and a larger transfer flow rate. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG.  1    is an external perspective view of a pump according to a first embodiment of the present invention. 
         FIG.  2    is a planar view showing a main part configuration of the pump according to the first embodiment of the present invention. 
         FIG.  3    is an exploded perspective view of the pump according to the first embodiment of the present invention. 
         FIG.  4    is a perspective view of a coil core portion in the pump according to the first embodiment of the present invention. 
         FIG.  5    is a perspective view of a movable body in the pump according to the first embodiment of the present invention. 
         FIG.  6    is a horizontal cross-sectional view showing an internal configuration of the pump according to the first embodiment of the present invention. 
         FIG.  7    is an exploded perspective view of a pump unit in the pump according to the first embodiment of the present invention. 
         FIG.  8    is a view showing an air flow path of the pump unit of the pump according to the first embodiment of the present invention. 
       Each of  FIG.  9 A  and  FIG.  9 B  is a view illustrating a discharge and suction operation for air in the pump according to the first embodiment of the present invention. 
         FIG.  10    is a view showing a magnetic spring of the pump according to the first embodiment of the present invention. 
         FIG.  11    is a view showing a configuration of a magnetic circuit of the pump according to the first embodiment of the present invention. 
       Each of  FIG.  12 A  and  FIG.  12 B  is a schematic diagram which is referred to explain operation of the pump unit in the pump according to the first embodiment of the present invention. 
       Each of  FIG.  13 A  and  FIG.  13 B  is a schematic diagram which is referred to explain the operation of the pump unit if the number of pump units is one. 
         FIG.  14    is an external perspective view of a pump according to a second embodiment of the present invention. 
         FIG.  15    is a planar view showing a main part configuration of the pump according to the second embodiment of the present invention. 
         FIG.  16    is an exploded perspective view of the pump according to the second embodiment of the present invention. 
         FIG.  17    is a perspective view of a coil core portion in the pump according to the second embodiment of the present invention. 
         FIG.  18    is a perspective view of a movable body in the pump according to the second embodiment of the present invention. 
         FIG.  19    is a horizontal cross-sectional view showing an internal configuration of the pump according to the second embodiment of the present invention. 
         FIG.  20    is a view showing a configuration of a magnetic circuit of the pump according to the second embodiment of the present invention. 
         FIG.  21    is an external perspective view of a pump according to a third embodiment of the present invention. 
         FIG.  22    is a horizontal cross-sectional view showing an internal configuration of the pump according to the third embodiment of the present invention. 
         FIG.  23    is an exploded perspective view of the pump according to the third embodiment of the present invention. 
         FIG.  24    is a perspective view of a coil core portion in the pump according to the third embodiment of the present invention. 
         FIG.  25    is a perspective view of a movable body in the pump according to the third embodiment of the present invention. 
         FIG.  26    is a view showing a configuration of a magnetic circuit of the pump according to the third embodiment of the present invention. 
         FIG.  27    is an external perspective view of a pump according to a fourth embodiment of the present invention. 
         FIG.  28    is a perspective view showing an internal configuration of the pump according to the fourth embodiment of the present invention. 
         FIG.  29    is a horizontal cross-sectional view showing the internal configuration of the pump according to the fourth embodiment of the present invention. 
         FIG.  30    is an exploded perspective view of the pump according to the fourth embodiment of the present invention. 
         FIG.  31    is a perspective view of a coil core portion in the pump according to the fourth embodiment of the present invention. 
         FIG.  32    is a perspective view of a movable body in the pump according to the fourth embodiment of the present invention. 
         FIG.  33    is a view showing a configuration of a magnetic circuit of the pump according to the fourth embodiment of the present invention. 
         FIG.  34    is an external perspective view of a pump according to a fifth embodiment of the present invention. 
         FIG.  35    is an exploded perspective view of the pump according to the fifth embodiment of the present invention. 
         FIG.  36    is a horizontal cross-sectional view showing an internal configuration of the pump according to the fifth embodiment of the present invention. 
         FIG.  37    is an exploded perspective view of a pump unit in the pump according to the fifth embodiment of the present invention. 
         FIG.  38    is a view showing an air flow path of the pump unit in the pump according to the fifth embodiment of the present invention. 
       Each of  FIG.  39 A  and  FIG.  39 B  is a schematic view which is referred to explain reciprocating rotational movement of a movable body in the pump according to the fifth embodiment of the present invention. 
         FIG.  40    is a view schematically showing an air supply device according to a sixth embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, description will be given to embodiments of the present invention with reference to the accompanying drawings. 
     First Embodiment 
       FIG.  1    is an external perspective view of a pump according to a first embodiment of the present invention.  FIG.  2    is a planar view showing a main part configuration of the pump according to the first embodiment of the present invention.  FIG.  3    is an exploded perspective view of the pump according to the first embodiment of the present invention.  FIG.  4    is a perspective view of a coil core portion in the pump according to the first embodiment of the present invention.  FIG.  5    is a perspective view of a movable body in the pump according to the first embodiment of the present invention.  FIG.  6    is a horizontal cross-sectional view showing an internal configuration of the pump according to the first embodiment of the present invention.  FIG.  7    is an exploded perspective view of a pump unit in the pump according to the first embodiment of the present invention. 
     When description is given to a pump of each embodiment with reference to  FIGS.  1  to  7    and  FIGS.  8  to  35   , it is assumed that a vibration direction of a movable body which performs reciprocating rotation in a vibration actuator of the pump is defined as a direction shown in  FIG.  2   . The description will be given with assuming that two directions perpendicular to this direction are respectively defined as a horizontal direction (a left-right direction) and a height direction (a vertical direction, also referred to as a thickness direction). Further, in the present embodiment, each expression indicating the directions such as “left-right (lateral)” and “height (vertical)” used to explain a configuration and operation of each part of the pump is not an absolute expression but a relative expression. Although these expressions are appropriate when each part of the pump take a posture shown in each figure, these expressions should be appropriately interpreted depending on the posture of each part of the pump if the posture is changed. 
     Entire Configuration of Pump  1   
     A pump  1  shown in  FIG.  1    and  FIG.  2    is a pump for discharging air by utilizing an action of a vibration actuator  10  which can be electromagnetically driven. Although the description will be given with assuming that the pump has a function of discharging and suctioning air in the present embodiment and each embodiment, a target object to be discharged and suctioned by the pump is not limited to air as long as it is fluid. In particular, it is preferable that the target object to be discharged and suctioned by the pump is gas. 
     As shown in  FIG.  1   , the pump  1  has a flat plate-like shape in which a height (a length in the vertical direction in the drawings, which corresponds to a thickness) is shorter than both of a horizontal length (a length in the left-right direction in the drawings) and a vertical length (a length in the depth direction in the drawings, which can be also referred to as the vibration direction). Further, the vertical length is shorter than the horizontal length. In this regard,  FIG.  1    is the perspective view of the pump  1  viewed from a rear side thereof. 
     The pump  1  of the present embodiment includes a vibration actuator  10  in which a movable body  30  is provided so as to freely perform reciprocating rotation with respect to a fixed body  20  through a shaft portion  40  and pump units  80  ( 80   a ,  80   b ) for discharging and suctioning air due to driving of the vibration actuator  10 . 
     In the present embodiment, the movable body  30  is provided in a case  21  of the fixed body  20  through the shaft portion  40  so that the movable body  30  can freely perform the reciprocating rotation. 
     Due to a collaborative work of core portions  60  ( 60   a ,  60   b ) around which coils  50   a ,  50   b  are respectively wound and magnets  70  ( 70   a ,  70   b ), the movable body  30  can reciprocate (that is, vibrate) with respect to the fixed body  20  along an axial direction of the shaft portion  40 . The pump  1  can discharge and suction the air through a discharge portion  86  by utilizing vibration of the movable body  30 . 
     In the pump  1  of the present embodiment, the movable body  30  is provided in the case  21  having a rectangular shape in a planar view thereof so that the movable body  30  can freely perform the reciprocating rotation around the shaft portion  40  disposed at a center of the case  21 . 
     The magnets  70   a ,  70   b  are respectively provided on the inner surface sides of both wall portions of the case  21  separated from each other in a longitudinal direction of the movable body  30 . A coil core portion  62   a  including the coil  50   a  and the core portion  60   a  is provided on an inner surface of the wall portion of the case  21  of the fixed body  20  which faces the magnet  70   a . Another coil core portion  62   b  including the coil  50   b  and the core portion  60   b  is provided on an inner surface of the wall portion of the case  21  of the fixed body  20  which faces the magnet  70   b . Each of the magnets  70   a ,  70   b  is preferably a permanent magnet, for example. Further, it is preferable that each of magnets  70 A,  70 B,  70 C described later is also a permanent magnet. 
     Vibration Actuator  10   
     The vibration actuator  10  includes the fixed body  20 , the shaft portion  40  and the movable body  30  supported by the shaft portion  40  so that the movable body  30  can freely perform the reciprocating rotation with respect to the fixed body  20 . Regarding a configuration of the vibration actuator  10 , the magnets  70  ( 70   a ,  70   b ) are provided on one of the fixed body  20  and the movable body  30 . Further, the coil core portions  62  ( 62   a ,  62   b ) which are disposed so that magnetized surfaces of cores of each coil core portion  62   a ,  62   b  respectively face the magnets  70   a ,  70   b  are provided on the other one of the fixed body  20  and the movable body  30 . In the present embodiment, the magnets  70   a ,  70   b  are provided on the movable body  30  and the coil core portions  62  ( 62   a ,  62   b ) are provided on the fixed body  20 . In other words, the movable body  30  includes the magnets  70   a ,  70   b  and the fixed body  20  includes the coil core portions  62   a ,  62   b.    
     Fixed Body  20   
     The fixed body  20  includes the case  21 , a cover  22  and the coil core portions  62   a ,  62   b . Further, the pump units  80  ( 80   a ,  80   b ) are provided on the fixed body  20 . 
     The case  21  serves as a housing of the pump  1  and has a rectangular box-like shape opened to one side. The shaft portion  40  is provided to stand on the case  21  to pivotally support the movable body  30  disposed in the case  21 . 
     In addition, the coil core portions  62   a ,  62   b  are respectively disposed on the inner surfaces of both wall portions of the case  21  separated from each other in a longitudinal direction of the case  21  so as to respectively face the magnets  70   a ,  70   b  on the movable body  30 . 
     The cover  22  covers an opening portion of the case  21 , that is an opening portion opening toward the upper side in the present embodiment. With this configuration, the case  21  and the cover  22  serve as a hollow electromagnetic shield and the pump  1  is formed in a flat plate-like shape. 
     The shaft portion  40  is provided on a center of a bottom surface of the case  21  in the horizontal direction and the depth direction of the case  21  so as to extend in the height direction of the case  21 . The shaft portion  40  is fitted and fixed to a shaft hole  23  of the cover  22  in a state that the shaft portion  40  is passed through a bearing portion  34  of the movable body  30  by press-fitting or bonding after the shaft portion  40  is inserted into the shaft hole  23 . With this configuration, the shaft portion  40  is supported in a state that the shaft portion  40  is passed through the bearing portion  34  of the movable body  30  and bridged between the bottom surface of the case  21  and the cover  22 . 
     The coil core portions  62   a ,  62   b  are respectively disposed on the inner surfaces of both wall portions of the case  21  separated from each other in the longitudinal direction of the case  21  so as to face each other. Further, the coil core portions  62   a ,  62   b  are disposed so as to sandwich the movable body  30  in the longitudinal direction of the case  21 . 
     In the present embodiment, the coil core portions  62   a ,  62   b  are configured so as to have the same configuration and respectively provided at positions symmetrical around an axis of the shaft portion  40  in the planar view. 
     The core portions  60   a ,  60   b  are magnetic bodies which can be magnetized when an electrical current flows in the coils  50   a ,  50   b . The core portions  60   a ,  60   b  may be made of electromagnetic stainless material, sintered material, metal injection mold (MIM) material, a laminated steel sheet, an electrogalvanized steel sheet (SECC) or the like. In the present embodiment, each of the core portions  60   a ,  60   b  is constituted of laminated cores made of the laminated steel sheet. 
     The core portions  60   a ,  60   b  respectively have cores  601   a ,  601   b  around which the coils  50   a ,  50   b  are respectively wound and magnetic poles (hereinafter, for convenience, referred to as “core magnetic poles”)  602   a ,  603   a ,  602   b ,  603   b  formed continuously with both end portions of the cores  601   a ,  601   b.    
     In the present embodiment, each of the core magnetic poles  602   a ,  603   a ,  602   b ,  603   b  has a magnetic pole surface curved so as to have an arc planar shape corresponding to a shape of a magnetized surface of each of the magnets  70   a ,  70   b  which can perform reciprocating rotation. 
     The core magnetic poles  602   a ,  603   a  of the core portion  60   a  face the magnet  70   a  and the core magnetic poles  602   b ,  603   b  of the core portion  60   b  face the magnet  70   b . The core magnetic poles  602   a ,  603   a ,  602   b ,  603   b  are aligned in a rotation direction of the reciprocating rotation of the movable body  30 . 
     The core magnetic poles  602   a ,  603   a ,  602   b ,  603   b  are preferably disposed on a circumference of a circle around the shaft portion  40 . This circumference is a circumferential track along a movement track of the magnets  70   a ,  70   b.    
     In the coil core portions  62   a ,  62   b , the core magnetic poles  602   a ,  603   a ,  602   b ,  603   b  of the core portions  60   a ,  60   b  around which the coils  50   a ,  50   b  are respectively wound are disposed so as to face a magnetization direction of the magnets  70   a ,  70   b.    
     The coils  50   a ,  50   b  in the core portions  60   a ,  60   b  are connected to, for example, a power supply unit (not shown). When the electrical current is supplied from the power supply unit to the coils  50   a ,  50   b , the core magnetic poles  602   a ,  603   a ,  602   b ,  603   b  are excited. When the core magnetic poles  602   a ,  603   a ,  602   b ,  603   b  are excited, the core magnetic poles  602   a ,  602   b  are excited so as to have a polarity differing from a polarity of the core magnetic poles  603   a ,  603   b  in each of the core portions  60   a ,  60   b.    
     Movable Body  30   
     As shown in  FIG.  2   ,  FIG.  3   ,  FIG.  5    and  FIG.  6   , the movable body  30  is disposed in the case  21  of the fixed body  20  so as to extend in a direction (the longitudinal direction of the case  21 ) perpendicular to the shaft portion  40  (the rotational axis of the movable body  30 ). 
     The movable body  30  is supported in the case  21  so that the movable body  30  can freely perform the reciprocating rotation around the shaft portion  40 . The movable body  30  includes a movable body main portion  32 , the bearing portion  34 , the pair of magnets  70   a ,  70   b  disposed so that the plurality of magnetic poles (three magnetic poles in the present embodiment) of each of the magnets  70   a ,  70   b  are alternately disposed in the rotation direction (the depth direction) and pressing portions  35 . 
     The bearing portion  34  is fixed to the movable body main portion  32  and the shaft portion  40  is passed through the bearing portion  34 . The pair of magnets  70   a ,  70   b  are fixed to the movable body main portion  32  so as to sandwich the shaft portion  40  passed through the bearing portion  34 . 
     The movable body main portion  32  may or may not be a magnetic body (a ferromagnetic body). In the present embodiment, the movable body main portion  32  is a yoke and serves as a weight of the movable body  30 . The movable body main portion  32  is constituted by laminating yoke iron cores, for example. The constituent material of the movable body main portion  32  is not limited to metal material. Resin material or the like may be used as the constituent material of the movable body main portion  32 . 
     The movable body main portion  32  has a center opening portion  322  formed at a center portion of the movable body main portion  32  and to which the bearing portion  34  is fixed and arm portions  324   a ,  324   b  respectively extending in opposite directions from the center portion. Each of the arm portions  324   a ,  324   b  has an elongated flat plate-like shape and end portions of the arm portions  324   a ,  324   b  are formed so as to protrude in a direction perpendicular to the extending direction. Further, magnet fixing portions  326   a ,  326   b  are respectively formed on tip end surfaces of the arm portions  324   a ,  324   b.    
     A tip end surface of each of the magnet fixing portions  326   a ,  326   b  is formed to be curved in an arc shape. The magnets  70   a ,  70   b  are respectively fixed to the tip end surfaces of the magnet fixing portions  326   a ,  326   b . The pressing portions  35  are respectively provided on the arm portions  324   a ,  324   b.    
     Magnets  70   a ,  70   b    
     The magnets  70   a ,  70   b  constitute magnetic circuits for driving the vibration actuator  10  together with the coil core portion  62   a ,  62   b  which are disposed to respectively face the magnets  70   a ,  70   b.    
     Each of the magnets  70   a ,  70   b  has a magnetic pole surface  72  serving as a plurality of magnetic poles. The magnets  70   a ,  70   b  are disposed so that the magnetic pole surface  72  of the magnet  70   a  and the magnetic pole surface  72  of the magnet  70   b  are directed toward opposite sides through the shaft portion  40 . In the present embodiment, the magnets  70   a ,  70   b  are respectively provided on both end portions of the movable body main portion  32  through which the shaft portion  40  is passed through at the center portion thereof. The end portions of the movable body main portion  32  are separated from each other in the extending direction of the movable body main portion  32 . Namely, the magnets  70   a ,  70   b  are respectively provided on tip end portions of the arm portions  324   a ,  324   b  so that the magnetic pole surfaces  72  of the magnets  70   a ,  70   b  are directed toward the outside. 
     As shown in  FIGS.  2 ,  3 ,  5 ,  6    and  FIG.  10   , the magnetic pole surface  72  contains three different magnetic poles  721 ,  722 ,  723  alternately disposed. In this regard, each of the magnets  70   a ,  70   b  may be configured by alternately arranging magnets (magnet pieces) having different magnetic poles or may be magnetized so as to have different magnetic poles alternately disposed in the rotation direction. The same discussion can be applied to magnets of the respective embodiments described later. The magnets  70   a ,  70   b  are constituted of, for example, Nd sintered magnets or the like. 
     The magnetic poles  721 ,  722 ,  723  of each of the magnets  70   a ,  70   b  are disposed so as to be adjacent to each other in the depth direction perpendicular to an axis line of the shaft portion  40  through the shaft portion  40 , that is, in the rotation direction. 
     The magnets  70   a ,  70   b  are respectively disposed on both end portions of the movable body  30  so that the magnetic pole surfaces  72  of the magnets  70   a ,  70   b  are positioned on the circumference of the circle around the shaft portion  40 . The magnets  70   a ,  70   b  are provided so that a center position of a length of the center magnetic pole  722  of each of the magnetic pole surfaces  72  in the rotation direction is positioned at a center position between the core magnetic poles  602   a ,  603   a  in a normal state, that is, in a non-energization state that the electrical current is not supplied into the coils  50   a ,  50   b.    
     In the present embodiment, the magnets  70   a ,  70   b  are disposed on the movable body  30  so as to respectively face the coil core portions  62   a ,  62   b  respectively provided on the inner surfaces of both wall portions of the housing (the case  21 ) and at positions which are farthest apart from the shaft portion  40  through the arm portions  324   a ,  324   b.    
     Pressing Portion  35   
     The pressing portions  35  press movable walls  822  of a pair of sealed chambers  82  of the pump units  80  when the movable body  30  performs rotational movement. Specifically, each of the pressing portions  35  includes a pair of pushers  351  for pressing the movable walls  822  of the pair of the sealed chambers  82  when the arm portions  324   a ,  324   b  perform the reciprocating rotation. 
     The pairs of pushers  351  of the pressing portions  35  are respectively provided on the arm portions  324   a ,  324   b  so as to protrude in the width direction, that is, in the rotation direction of the arm portions  324   a ,  324   b . Each of the pressing portions  35  may be formed so as to linearly press the movable wall  822  in a facing direction even when the movable body  30  rotates, for example. In the present embodiment, each pusher  351  of the pressing portions  35  moves in an arc track around the shaft portion  40  and abuts against the movable wall  822  to press the movable wall  822 . The pressing portion  35  may be configured in any manner as long as it is configured to be displaced toward the movable wall side when the movable body  30  performs the rotational movement to press and move the movable wall  822 . Preferably, the movable wall  822  is disposed so as to intersect a movement track of the pressing portion  35  and the moving pressing portion  35  is disposed so as to make surface-contact with the movable wall  822 . 
     For example, as shown in each of  FIG.  9 A  and  FIG.  9 B , the pressing portion  35  is fixed with respect to each of the arm portions  324   a ,  324   b  through a shaft protrusion  353  axially attached to a round hole  328  so that the shaft protrusion  353  can perform pivotal movement and a guide protrusion  352  guided by a long hole  329 . 
     With this configuration, the pusher  351  swings in the arc track when the movable body  30  performs the reciprocating rotation. For example, a tip end of the pusher  351  may swing by loosely fitting the guide protrusion  352  into the long hole  329  to allow the pressing portion  35  to swing with respect to the arm portions  324   a ,  324   b  through the guide protrusion  352 . In this case, although the pressing portion  35  moves in the arc track when the movable body  30  rotates, the pusher  351  can linearly move with respect to the movable wall  822  to press the movable wall  822 . 
     In the present embodiment, the pressing portion  35  is connected to the movable wall  822  of the pump unit  80  through the pusher  351 . The pusher  351  is inserted into an insertion portion  822   a  of the movable wall  822  serving as a diaphragm when the movable body  30  performs the rotational movement to push and displace the movable wall  822  in the rotation direction. The pressing portion  35  moves toward the side of the movable wall  822  to press the movable wall  822  when the movable body  30  rotates. Further, when the movable body  30  oppositely rotates, the pressing portion  35  moves toward the side opposite to the movable wall  822  and gradually decreases pressure with respect to the movable wall  822  to displace the movable wall  822  in a direction opposite to the pressing direction. 
     The bearing portion  34  is constituted of a sintered sleeve bearing, for example. The bearing portion  34  is fitted into the center opening portion  322  of the movable body main portion  32  so that the shaft portion  40  is positioned on a center axis of the movable body main portion  32 . 
     When the electrical current is not supplied to the coils  50   a ,  50   b , the movable body main portion  32  is biased so as to be positioned at a center of the case  21  (the fixed body  20 ) in longitudinal direction by functions of magnetic springs provided by the core portions  60   a ,  60   b  and the magnets  70   a ,  70   b.    
     Pump Unit  80   
     Each of the pump units  80  ( 80   a ,  80   b ) includes the movable walls  822 , the sealed chambers  82  defined by the movable walls  822 , a suction portion  83 , valves  84 , the discharge portion  86  and a discharge flow path portion  88 . 
     Movable Wall  822   
     The movable wall  822  forms a wall portion for partitioning between a chamber forming portion  824  and the discharge flow path portion  88  and is provided so as to be displaceable. The movable wall  822  is displaced to change a volume in the sealed chamber  82 . The movable wall  822  constitutes the sealed chamber  82  together with the chamber forming portion  824 . 
     The movable wall  822  is formed of, for example, elastically deformable material and is provided so as to close the chamber forming portion  824 . For example, the movable wall  822  is a diaphragm. 
     The movable wall  822  has the insertion portion  822   a  into which the pusher  351  of the pressing portion  35  is inserted and is connected to the pressing portion  35  through the insertion portion  822   a . The movable wall  822  is displaced when the movable wall  822  is pressed by the pressing portion  35  which moves in accordance with the rotation of the movable body  30 . 
     The movable wall  822  is elastically deformed when the movable wall  822  is pressed toward the chamber forming portion  824  by the pressing portion  35  through the insertion portion  822   a  and deformed to reduce a volume of the chamber forming portion  824 . Since the movable wall  822  is displaced toward the chamber forming portion  824  and protrudes into the chamber forming portion  824 , the movable wall  822  can change the volume in the sealed chamber  82 . 
     The movable wall  822  is inserted into the chamber forming portion  824  by one-side rotation movement (swing to one side of the rotation direction) of the reciprocating rotation of the movable body  30  to press the inside of the chamber forming portion  824  and reduce the volume in the sealed chamber  82  for discharging the air. On the other hand, when the movable body  30  rotates in the other side (moves toward the other side of the rotation direction), the movable wall  822  increases the volume in the sealed chamber  82  to suction the air. 
     Sealed Chamber  82   
     The sealed chamber  82  is a sealed space to which the suction portion  83  and the discharge portion  86  are connected and whose volume can be changed by the displacement of the movable wall  822 . The discharge portion  86  has a discharge port communicated with the outside and discharges the air from the pump  1  to the outside through the discharge port. For example, the discharge port may be an opening communicated with the discharge portion  86  connected to a bottom surface of the sealed chamber  82 . 
     In the pump unit  80 , when the movable wall  822  is pressed by the pressing portion  35 , the movable wall  822  is elastically deformed toward the inside of the sealed chamber  82  to press the air in the sealed chamber  82 . The pressed air in the sealed chamber  82  is discharged to the outside through the discharge portion  86 . When the movable wall  822  moves so as to return to an initial position, that is, when the pressed state by the pressing portion  35  is released and the volume in the sealed chamber  82  increases from the pressed state, the air is suctioned from the outside into the sealed chamber  82  through the suction portion  83 . For example, the suction portion  83  has a suction port and can suction the air into the sealed chamber  82  through the suction port. For example, the suction port may be an opening communicated with the suction portion  83  in the chamber forming portion  824 . 
     Each of the pump units  80  ( 80   a ,  80   b ) is disposed in the case  21  along the extending direction of the movable body  30 , that is, along side wall portions of the case  21  extending in the longitudinal direction of the case  21 . Further, the pump units  80  ( 80   a ,  80   b ) are disposed so as to sandwich the movable body main portion  32  of the movable body  30  in the depth direction of the case  21 . 
     For example, the pump unit  80  includes a base  801 , a diaphragm portion  802 , a cylinder portion  803 , a valve portion  804 , a valve cover portion  805 , a partition portion  806  and a flow path forming portion  807 . Each of the base  801 , the diaphragm portion  802 , the cylinder portion  803 , the valve portion  804 , the valve cover portion  805 , the partition portion  806  and the flow path forming portion  807  has an elongated plate-like shape extending in the longitudinal direction of the case  21  and constitutes the pump unit  80  having an internal space sealed by stacking these portions. 
     The base  801  has an opening. The insertion portion  822   a  of the diaphragm portion  802  is passed through the opening of the base  801  from a rear surface side of the base  801  so as to protrude toward a front surface side of the base  801 . The base  801  and the flow path forming portion  807  constitute a housing of the pump unit  80  having a strip shape. 
     The diaphragm portion  802  is formed from elastic material such as rubber. The diaphragm portion  802  has the insertion portion  822   a  and the movable wall  822 . The chamber forming portion  824  of the cylinder portion  803  is disposed on the rear surface side of the movable wall  822  which has flexibility and can be elastically deformed. The diaphragm portion  802  and the cylinder portion  803  are attached to each other so that the movable wall  822  of the diaphragm portion  802  and the chamber forming portion  824  of the cylinder portion  803  define the sealed chamber  82  which is a sealed space. 
     The cylinder portion  803  has the chamber forming portion  824  and two communication holes formed in a surface facing the movable wall  822  in the sealed chamber  82  so as to be respectively communicated with the discharge portion  86  and the suction portion  83 . The two communication holes are respectively connected to the discharge flow path portion  88  and the suction portion  83  of the flow path forming portion  807  and the valve cover portion  805  through the valves  84  of the valve portion  804  which are attached from the rear surface side of the cylinder portion  803  so as to overlap with the two communication holes. 
     The valve portion  804  is attached to the valve cover portion  805 . The valve  84  connected to the discharge portion  86  is configured to communicate with the discharge portion  86  of the flow path forming portion  807  when the volume in the sealed chamber  82  decreases. On the other hand, the valve  84  connected to the discharge portion  86  is configured to be closed when the volume in the sealed chamber  82  increases. 
     The valve portion  804  is attached to the valve cover portion  805 . The valve  84  connected to the suction portion  83  is configured to be closed when the volume in the sealed chamber  82  decreases. On the other hand, the valve  84  connected to the suction portion  83  is configured to communicate with the suction portion  83  of the flow path forming portion  807  when the volume in the sealed chamber  82  increases. 
     In the present embodiment, each of the pump units  80  ( 80   a ,  80   b ) has the pair of sealed chambers  82  each constituted of the chamber forming portion  824  and the movable wall  822 . Each of the pump units  80  ( 80   a ,  80   b ) is disposed so that its own pair of sealed chambers  82  respectively face side surfaces of the arm portions  324   a ,  324   b  extending in directions opposite to each other through the shaft portion  40 . Namely, the pump units  80  ( 80   a ,  80   b ) are disposed so as to face each other at positions where the arm portions  324   a ,  324   b  are sandwiched between the pairs of sealed chambers  82  of the pump units  80  ( 80   a ,  80   b ) in the direction of the reciprocation and rotation movement of the arm portions  324   a ,  324   b.    
     Each of  FIG.  9 A  and  FIG.  9 B  is a view showing an air discharge operation or an air suction operation of the pump according to the first embodiment of the present disclosure. 
     When the pressing portion  35  moves toward the movable wall  822 , the pusher  351  contacts and presses the movable wall  822  through the insertion portion  822   a  as shown in  FIG.  9 A . As a result, the movable wall  822  is displaced toward the side of the chamber forming portion  824  and thus the air in the sealed chamber  82  is pressed and compressed. The compressed air flows to the side of the discharge portion  86  which is only one communicated with the sealed chamber  82  through the opened valve  84  (see white arrows in  FIG.  9 A ). 
     On the other hand, when the pressing portion  35  reversely moves in the rotation direction, that is, moves away from the side of the pump unit  80 , the movable wall  822  elastically returns in accordance with the movement of the pressing portion  35  and the volume in the sealed chamber  82  is returned, that is, increased as shown in  FIG.  9 B . At this time, the valve  84  connected to the discharge portion  86  is tightened to close the discharge path and the valve  84  connected to the suction portion  83  is opened. Thus, the air is suctioned into the sealed chamber  82  through the suction portion  83  (indicated by white arrows in the  FIG.  9 B ). 
     Magnetic Circuit Configuration 
     In the present embodiment, the core portions  60   a ,  60   b  which are magnetic members are disposed in the case  21  so as to respectively face the magnets  70   a ,  70   b  with being apart from the magnets  70   a ,  70   b  in the longitudinal direction as shown in  FIG.  2    and  FIG.  6   . The magnets  70   a ,  70   b  are respectively disposed at both ends of the movable body  30  so as to face each other through the shaft portion  40 . The core portions  60   a ,  60   b  are respectively disposed on inner surfaces of both wall portions of the case  21  in the longitudinal direction so as to face each other with being apart from each other in the longitudinal direction. 
     Magnetic attraction force is generated between the core portion  60   a  and the magnet  70   a  and between the core portion  60   b  and the magnet  70   b . Since these two kinds of magnetic attraction force generated in the longitudinal direction (the extending direction of the arm portion  324   a ,  324   b ) are generated in opposite directions on one straight line through the shaft portion  40 , these two kinds of magnetic attraction force cancel each other. 
       FIG.  10    is a view showing a magnetic spring of the pump unit according to the first embodiment of the present invention. In the pump  1 , a magnetic circuit provided by the coil core portion  62   a  and the magnet  70   a  and a magnetic circuit provided by the coil core portion  62   b  and the magnet  70   b  are configured to be point-symmetrically around the shaft portion  40 . Thus, only the magnetic circuit provided by the coil core portion  62   a  and the magnet  70   a  will be described in  FIG.  10    and description for the magnetic circuit provided by the coil core portion  62   b  and the magnet  70   b  will be omitted. 
     In  FIG.  10   , the magnet  70   a  has a configuration in which the magnetic poles  721 ,  722 ,  723  on the magnetic pole surface  72  facing the core portion  60   a  are respectively magnetized as N pole, S pole and N pole. Each of the magnetic poles  721  to  723  on the magnetic pole surface  72  of the magnet  70   a  respectively attracts the core magnetic poles  602   a ,  603   a  close to each of the magnetic poles  721  to  723 . 
     The center magnetic pole  722  of the magnet  70   a  attracts both of the core magnetic poles  602   a ,  603   a . The magnetic pole  721  of the magnet  70   a  attracts the core magnetic pole  602   a . The magnetic pole  723  of the magnet  70   a  attracts the core magnetic pole  603   a . As a result, the center magnetic pole  722  of the magnet  70   a  is located at the center of the coil core portion  62   a , that is, at a position between the core magnetic poles  602   a ,  603   a.    
     In the pump  1 , when the electrical current flows in the coil  50   a  of the coil core portion  62   a , the core magnetic poles  602   a ,  603   a  of the core portion  60   a  are excited with different polarities. As a result, thrust force is generated with respect to the movable body  30  in accordance with the relationship with the magnet  70   a  disposed so as to face the coil core portion  62   a . The same discussion can be applied to the magnetic circuit provided by the coil core portion  62   b  and the magnet  70   b . By periodically changing the direction of the electric current supplied to the coils  50   a ,  50   b , the movable body  30  including the magnets  70   a ,  70   b  performs the reciprocating rotational movement (reciprocating rotational vibration) in the rotation direction around the shaft portion  40 . 
     Operation of Pump  1   
     An example of the operation of the pump  1  will be described with reference to  FIG.  11   .  FIG.  11    is a view showing the magnetic circuit configuration of the pump according to the first embodiment of the present invention. In this regard, similarly to the description with reference to  FIG.  10   , only the magnetic circuit provided by the coil core portion  62   a  and the magnet  70   a  will be described in the description for the example of the operation of the pump  1  with reference to  FIG.  11    and description for the magnetic circuit provided by the coil core portion  62   b  and the magnet  70   b  will be omitted. 
     It is assumed that the magnet  70   a  has three different polarities on the magnetic pole surface  72  so that the three different polarities are alternately arranged in the rotation direction. In the magnet  70   a  shown in  FIG.  11   , the central magnetic pole  722  is the S pole and each of the magnetic poles  721 ,  723  sandwiching the center magnetic pole  722  is the N pole on the magnetic pole surface  72  facing the core portion  60   a.    
     When the electrical current is supplied to the coil  50   a  of the coil core portion  62   a  to excite the core portion  60   a , the core magnetic pole  602   a  of the core portion  60   a  is magnetized with the S pole and the core magnetic pole  603   a  of the core portion  60   a  is magnetized with the N pole as shown in  FIG.  11   . 
     Since the magnetic pole  723  of the magnet  70   a  magnetized with the N pole faces the core magnetic pole  603   a  magnetized with the N pole as shown in  FIG.  11   , the magnetic pole  723  of the magnet  70   a  repels with respect to the core magnetic pole  603   a . In addition, since the magnetic pole  722  of the magnet  70   a  is magnetized with the S pole, magnetic attraction force is generated between the magnetic pole  722  and the core magnetic pole  603   a  magnetized with the N pole and the magnetic pole  722  repels with respect to the core magnetic pole  602   a  magnetized with the S pole. Further, since the magnetic pole  721  of the magnet  70   a  is magnetized with the N pole, magnetic attraction force is generated between the magnetic pole  721  and the core magnetic pole  602   a  magnetized with the S pole. 
     With this configuration, thrust force in the direction F1 is generated between the magnet  70   a  and the coil core portion  62   a , and thereby the movable body  30  is driven in the direction F1. 
     In a state that the electrical current is not supplied to the coil  50   a , the movable body  30  is located at a rotation reference position, that is a neutral position for the reciprocation movement by the magnetic attraction force of the magnetic spring. 
     Further, the electrical current is supplied to the coil  50   a  in the opposite direction to reverse the polarity of the core portion  60   a . Namely, the magnetic pole  603   a  of the core portion  60   a  facing the magnet  70   a  is magnetized with the S pole and the magnetic pole  602   a  of the core portion  60   a  is magnetized with the N pole. As a result, the magnet  70   a  facing the core portion  60   a  rotates in a direction (direction −F1) opposite to the direction F1. The movable body  30  is driven in the direction −F1 which is 180 degrees opposite to the direction F1. 
     In the movable body  30 , the relationship between the magnet  70   b  disposed on the opposite side of the magnet  70   a  through the shaft portion  40  and the coil core portion  62   b  is point-symmetrical with respect to the relationship between the magnet  70   a  and the coil core portion  62   a  around the shaft portion  40 . Thus, thrust force in the direction F1 or the direction −F1 is also generated between the magnet  70   b  and the coil core portion  62   b  similar to the thrust force generated between the magnet  70   a  and the coil core portion  62   a . With this configuration, the movable body  30  preferably performs the reciprocating rotation around the shaft portion  40  due to the magnetic attraction force and the repulsion force which are effectively generated in the magnetic circuits at both end portions of the movable body  30 . 
     This driving principle will be described in the following description. The driving principle of the vibration actuator  10  of the present embodiment is realized by all of the vibration actuators used in the following embodiments. 
     In the vibration actuator  10  of the present embodiment, when an inertial moment of the movable body  30  is defined as J [Kg*m 2 ] and a spring constant in the rotation direction is defined as K sp , the movable body  30  vibrates with respect to the fixed body  20  with a resonant frequency fr [Hz] calculated by the following equation (1). 
     
       
         
           
             
               
                 
                   Equation 
                   ⁢ 
                       
                   1 
                 
               
               
                  
               
             
             
               
                 
                   
                     f 
                     r 
                   
                   = 
                   
                     
                       1 
                       
                         2 
                         ⁢ 
                         π 
                       
                     
                     ⁢ 
                     
                       
                         
                           K 
                           sp 
                         
                         J 
                       
                     
                   
                 
               
               
                 (1) 
               
             
           
         
       
     
     In the pump  1  of the present embodiment, an alternating current having a frequency substantially equal to the resonant frequency fr of the movable body  30  is supplied to the coils  50   a ,  50   b  to excite the core portions  60   a ,  60   b  (more specifically, the core magnetic poles  602   a ,  603   a ,  602   b ,  603   b ) with the coils  50   a ,  50   b . As a result, it is possible to efficiently drive the movable body  30 . 
     The movable body  30  in the vibration actuator  10  of the present embodiment is in a state that it is supported by a spring mass system structure constituted of the magnetic springs provided by the magnets  70   a ,  70   b  and the coil core portions  62   a ,  62   b  respectively having the coils  50   a ,  50   b  and the core portions  60   a ,  60   b . Thus, when the alternating current having the frequency equal to the resonance frequency fr of the movable body  30  is supplied to the coils  50   a ,  50   b , the movable body  30  is driven in a resonance condition. 
     A motion equation and a circuit equation representing the driving principle of the vibration actuator  10  are shown below. The vibration actuator  10  is driven based on the motion equation expressed by the following equation (2) and the circuit equation expressed by the following equation (3). 
     
       
         
           
             
               
                 
                   Equation 
                   ⁢ 
                       
                   2 
                 
               
               
                  
               
             
             
               
                 
                   
                     J 
                     ⁢ 
                     
                       
                         
                           d 
                           2 
                         
                         ⁢ 
                         θ 
                         ⁢ 
                         
                           ( 
                           t 
                           ) 
                         
                       
                       
                         dt 
                         2 
                       
                     
                   
                   = 
                   
                     
                       
                         K 
                         f 
                       
                       ⁢ 
                       
                         i 
                         ⁡ 
                         ( 
                         t 
                         ) 
                       
                     
                     - 
                     
                       
                         K 
                         sp 
                       
                       ⁢ 
                       
                         θ 
                         ⁡ 
                         ( 
                         t 
                         ) 
                       
                     
                     - 
                     
                       D 
                       ⁢ 
                       
                         
                           d 
                           ⁢ 
                           
                             θ 
                             ⁡ 
                             ( 
                             t 
                             ) 
                           
                         
                         dt 
                       
                     
                   
                 
               
               
                 
                   ( 
                   2 
                   ) 
                 
               
             
           
         
       
         
         
           
             J: Inertial moment [Kg*m 2 ] 
             θ(t): Displacement angle [rad] 
             K f : Thrust constant [Nm/A] 
             i(t): Current [A] 
             K sp : Spring constant [Nm/rad] 
             D: Damping coefficient [Nm/(rad/s)] 
           
         
       
    
     
       
         
           
             
               
                 
                   
                     e 
                     ⁡ 
                     ( 
                     t 
                     ) 
                   
                   = 
                   
                     
                       Ri 
                       ⁡ 
                       ( 
                       t 
                       ) 
                     
                     + 
                     
                       L 
                       ⁢ 
                       
                         
                           di 
                           ⁡ 
                           ( 
                           t 
                           ) 
                         
                         dt 
                       
                     
                     + 
                     
                       
                         K 
                         e 
                       
                       ⁢ 
                       
                         
                           dx 
                           ⁡ 
                           ( 
                           t 
                           ) 
                         
                         dt 
                       
                     
                   
                 
               
               
                 
                   Equation 
                   ⁢ 
                       
                   3 
                 
               
             
           
         
       
         
         
           
             e(t): Voltage [V] 
             R: Resistance [Ω] 
             L: Inductance [H] 
             K e : Counter-electromotive force constant [V/(m/s)] 
           
         
       
    
     Namely, the inertial moment J [Kg*m 2 ], a displacement angle (rotational angle) θ(t) [rad], a thrust constant (torque constant) K f  [Nm/A], an electrical current i(t) [A], the spring constant K sp  [Nm/rad], a damping factor D [Nm/(rad/s)] and the like of the movable body  30  in the vibration actuator  10  of the pump  1  can be appropriately changed as long as they satisfy the equation (2). A voltage e(t) [V], a resistance R [Ω], an inductance L[H] and a counter-electromotive force constant K e  [V/(m/s)] can be appropriately changed as long as they satisfy the equation (3). 
     As described above, when the alternating current having the frequency corresponding to the resonance the resonant frequency fr determined by the inertial moment J of the movable body  30  and the spring constant K sp  of the magnetic spring is supplied to the coils  50   a ,  50   b , it is possible to efficiently obtain a large vibration output of the vibration actuator  10  of the pump  1 . 
     In the pump  1 , the volume in the sealed chamber  82  is changed by the displacement of the movable wall  822  (specifically, the deformation of the diaphragm) in the pump unit  80  when the movable body  30  performs the reciprocating rotation. Thus, the pump  1  can provide a pump function. In the following description, a flow rate of this pump function is set by the following equation (4) and pressure of this pump function is set by the following equation (5). 
       Equation 4 
         Q=Axf* 60  (4)
         Q: Flow rate [L/min]   A: Piston area [m 2 ]   x: Piston displacement [m]   f: Drive frequency [Hz]       

     
       
         
           
             
               
                 
                   Equation 
                   ⁢ 
                       
                   5 
                 
               
               
                  
               
             
             
               
                 
                   P 
                   = 
                   
                     
                       P 
                       0 
                     
                     ( 
                     
                       
                         
                           V 
                           + 
                           
                             Δ 
                             ⁢ 
                             V 
                           
                         
                         
                           V 
                           - 
                           
                             Δ 
                             ⁢ 
                             V 
                           
                         
                       
                       - 
                       1 
                     
                     ) 
                   
                 
               
               
                 
                   ( 
                   5 
                   ) 
                 
               
             
           
         
       
         
         
           
             P: Increased pressure [kPa] 
             P 0 : Atmospheric pressure [kPa] 
             V: Sealed chamber volume [m 3 ] 
             ΔV: Changed volume [m 3 ] 
             ΔV=Ax 
             A: Piston area [m 2 ] 
             x: Piston displacement [m] 
           
         
       
    
     Namely, a flow rate Q [L/min], a piston area A [m 2 ], a piston displacement x [m], a drive frequency f [Hz] and the like of the pump  1  can be appropriately changed as long as they satisfy the equation (4). Further, an increasing pressure [kPa], an atmospheric pressure P 0  [kPa], a sealed chamber volume V [m 3 ] and a changed volume ΔV [m 3 ]=the piston area [m 2 ] A*the piston displacement [m] can be appropriately changed as long as they satisfy the equation (5). 
     As described above, the pump  1  of the present embodiment has the vibration actuator  10  which can be electromagnetically driven and the pump units  80  ( 80   a ,  80   b ) which suction and discharge the air due to the electromagnetic drive of the vibration actuator  10 . 
     In the vibration actuator  10 , the fixed body  20  includes one of the coil core portion  62   a  having the coil  50   a  and the core portion  60   a  around which the coil  50   a  is wound and the magnet  70   a  disposed so as to face the end portion of the core portion  60   a . Further, the pump units  80  ( 80   a ,  80   b ) are provided on the fixed body  20 . The movable body  30  includes the other one of the coil core portion  62   a  and the magnet  70   a . Further, the movable body  30  is elastically held by the magnetic attraction force of the magnet  70   a . The shaft portion  40  reciprocally and rotatably supports the movable body  30 . The pump unit  80   a  includes the movable wall  822  which can be moved by the rotational movement of the movable body  30  and the sealed chamber  82  which communicates with the discharge portion  86  for the air and the suction portion  83  for the air and whose volume can be changed by the displacement of the movable wall  822 . The movable body  30  has the pressing portions  35  which move in the arc track around the shaft portion  40  when the movable body  30  performs the reciprocating rotational movement and contact with the movable wall  822  to press the movable wall  822 . The movable walls  822  are disposed in the moving direction of the pressing portions  35  and displaced to discharge the air in the sealed chamber  82  through the discharge portion  86  when the movable walls  822  are pressed by the pressing portion  35 . 
     Effect 
     The movable body  30  elastically supported by the magnetic springs provided by the magnets  70   a ,  70   b  and the coil core portions  62   a ,  62   b  vibrates with high efficiency due to the resonance. 
     Namely, as compared with a case that a rotary motor is utilized as a driving component of a pump, it is possible to reduce the thickness of the pump. Further, unlike a conventional pump using a piezoelectric element and whose performance is specialized in either one of the pressure or the flow rate, it is possible to set both of a desired pressure and a desired flow rate when discharging the air. 
     In addition, in the normal condition of the movable body  30 , the sealed chambers  82  of the pump units  80   a ,  80   b  are disposed so as to face each other in the direction perpendicular to the extending direction of the movable body  30  with sandwiching the pressing portions  35  of the movable body  30  from both sides of the reciprocating rotational movement. With this configuration, even when the movable body  30  is in the normal condition, that is when the movable body  30  is located at the reference position and the pressing portions  35  are respectively pressed toward the direction for moving the pressing portions  35  away from the sealed chambers  82  by the air remaining in the sealed chambers  82  of the pump units  80   a ,  80   b , the pressing force respectively applied to the pressing portions  35  by the air remaining in the sealed chambers  82  of the pump units  80   a ,  80   b  cancels each other. Therefore, it is possible to suitably locate the movable body  30  at the reference position for the reciprocating rotational movement. 
     Regarding a pump unit of a conventional pump, there is a possibility that the reference position of the movable body, that is, the rest position of the movable body changes due to pressing force (loads) generated with respect to the movable body when the pressure of the pump unit increases. If the movable body starts the reciprocating rotation from a position shifted from the reference position, the movable body may move within a movement range differing from the movement range when the movable body starts the reciprocating rotation from the reference position. In the pump unit of the conventional pump, this movement may shift the displacement position of the movable wall caused by the pressing portion and set as a distance from the reference position. Due to this shift of the displacement position of the movable wall, the air in the sealed chamber  82  cannot be sufficiently compressed and the desired discharge pressure and the desired flow rate for the air cannot be ensured. In this case, it is necessary to increase the distance, that is, the amplitude of the reciprocating rotational movement of the movable body. This requires to ensure a clearance for the increased movement in the case, and thereby it becomes impossible to downsize the pump. 
     On the other hand, according to the present embodiment, since the pressing force (loads) respectively applied to the pressing portions  35  by the air remaining in the sealed chambers  82  of the pump units  80   a ,  80   b  cancels each other, it is possible to suitably locate the movable body  30  at the reference position to vibrate the movable body  30  from the reference position. Therefore, it is possible to realize the pump  1  which can provide a higher pressure and can be downsized. 
     Each of  FIG.  12 A  and  FIG.  12 B  is a schematic diagram which is referred to explain operation of the pump unit in the pump according to the first embodiment of the present invention. Each of  FIG.  13 A  and  FIG.  13 B  is a schematic diagram which is referred to explain the operation of the pump unit if the number of pump units is one. 
     In the present embodiment, the sealed chambers  82  (which respectively correspond to the “air chambers” in  FIGS.  12 A- 12 B  and  FIGS.  13 A- 13 B ) in the pump units  80  ( 80   a ,  80   b ) are disposed so as to face each other in the direction perpendicular to the extending direction of the movable body  30  and sandwich the movable body  30  in the reciprocating rotational movement direction of the movable body  30 , that is, from both sides of the vibration direction of the arm portions  324   a ,  324   b  located at the reference position. 
     In the present embodiment, the four sealed chambers  82  are disposed to sandwich the shaft portion  40  and sandwich the arm portions  324   a ,  324   b  of the movable body  30  in the depth direction. Namely, in the present embodiment, the movable body  30  has the arm portions  324   a ,  324   b  which are respectively provided so as to extend toward the direction perpendicular to the axial direction of the shaft portion  40  from a position where the movable body  30  is axially supported by the shaft portion  40  so as to be freely reciprocated and rotated. The other one of the coil core portions  62   a ,  62   b  and the magnets  70   a ,  70   b  are respectively provided at the tip end portions (the magnet fixing portions  326   a ,  326   b ) of the arm portions  324   a ,  324   b.    
     The sealed chambers  82  are provided in pairs sandwiching the arm portions  324   a ,  324   b  of the movable body  30 . The pair of sealed chambers  82  (shown as the “air chambers” in  FIGS.  12 A- 12 B ) are disposed so as to face each other at positions for sandwiching the arm portions  324   a ,  324   b  in the reciprocating rotation direction of the arm portions  324   a ,  324   b  (the depth direction of the case  21 ). Each of the pressing portions  35  has the pair of pushers  351 ,  351  respectively corresponding to the pair of movable walls  822 . The movable walls  822  of the pair of the sealed chambers  82 ,  82  are respectively pressed by the corresponding pushers  351  when the arm portions  324   a ,  324   b  perform the reciprocating rotation. 
     As shown in  FIG.  12 A , the pressing portions  35  of the movable body  30  are respectively connected to the movable walls  822  defining the pair of the sealed chambers  82  (the “air chambers”) located on both sides of the reciprocating rotation direction of the reciprocating rotational movement of the movable body  30  in the present embodiment. 
     In the configuration in which the movable body  30  is elastically supported by the magnetic springs as described above, the movable walls  822  are displaced by loads generated when pressure in the sealed chambers  82  increases to press the movable body  30  through the pressing portions  35 . 
     At this time, since the pressing force (loads) applied to the movable body  30  from the pressing portions  35  of the pair of sealed chambers  82  cancel each other in the present embodiment as shown in  FIG.  12 B , the movable body  30  is stably held at the reference position. 
     On the other hand, it is assumed that the sealed chamber  82  (the “air chamber”) is disposed on only one side of the reciprocating rotation direction of the movable body  30  as shown in  FIGS.  13 A- 13 B . In this case, when the movable wall  822  of the one sealed chamber  82  is displaced toward the movable body  30 , the movable body  30  is pressed through the pressing portion  35  to offset the rest position of the movable body  30  from the reference position. In this configuration, it is required to more increase the amplitude of the vibration of the movable body  30  or more increase a movable range of the movable body  30  because of the increase of the pressure in the sealed chamber  82  unlike the present embodiment. 
     On the other hand, since the movable range of the movable body  30  can be reduced in the present embodiment, it is possible to downsize the pump  1 . 
     In addition, the movable body  30  has the pair of arm portions  324   a ,  324   b  which are axially supported by the shaft portion  40  at the center portion of the case  21  so as to be freely reciprocated and rotated and which oppositely extend from the center portion of the case  21  in the direction perpendicular to the axial direction of the shaft portion  40  in the present embodiment. 
     The other one (the magnets  70   a ,  70   b  in the present embodiment) of the coil core portions  62   a ,  62   b  and the magnets  70   a ,  70   b  is respectively provided on the tip end portions of the arm portions  324   a ,  324   b , that is, the magnet fixing portions  326   a ,  326   b.    
     On the other hand, the one (the coil core portions  62   a ,  62   b  in the present embodiment) of the coil core portions  62   a ,  62   b  and the magnets  70   a ,  70   b  is respectively provided on the fixed body  20  so as to face the other one (the magnets  70   a ,  70   b  in the present embodiment) of the coil core portions  62   a ,  62   b  and the magnets  70   a ,  70   b.    
     Each of the pump units  80  ( 80   a ,  80   b ) contains the pair of sealed chambers  82 . The pair of sealed chambers  82  of each pump unit  80  ( 80   a ,  80   b ) are disposed so as to be in parallel with each other along the extending direction of the pair of arm portions  324   a ,  324   b . Further, each of the pressing portions  35  has the pair of pushers  351  respectively corresponding to the pair of movable walls  822  of the sealed chamber  82  of the pump unit  80   a  and the movable wall  822  of the sealed chamber  82  of the pump unit  80   b . Each of the movable walls  822  of the sealed chambers  82  is pressed by the pressing portion  35  when the arm portions  324   a ,  324   b  performs the reciprocating rotation. 
     As described above, each of the pump units  80  ( 80   a ,  80   b ) of the present embodiment contains the plurality of sealed chambers  82  aligned in the longitudinal direction thereof. Further, the discharge flow paths and the discharge ports of the sealed chambers  82  are connected in parallel. As a result, when the movable body  30 , that is, the arm portions  324   a ,  324   b  perform the reciprocating rotation around the shaft portion  40 , the pushers  351  of the pressing portions  35  alternately press the movable walls  822  of the sealed chambers  82  disposed in parallel in the longitudinal direction. With this configuration, it is possible to provide the pump  1  with the high flow rate. 
     In addition, since the pump  1  of the present embodiment has the configuration in which the magnets  70   a ,  70   b  required to operate the magnetic springs are provided on one of the movable body  30  and the fixed body  20 , it is possible to reduce the number of parts of the pump  1  as compared with the configuration in which the magnets  70   a ,  70   b  are provided on both of the movable body  30  and the fixed body  20 . 
     As described above, since it is possible to reduce the number of parts of the pump  1 , it is possible to further reduce a cost of the pump  1  and reduce the number of assembly steps for the pump  1 . 
     Further, the movable body  30  is elastically supported by the magnetic springs of the magnetic circuits provided by the magnets  70   a ,  70   b  and the core portions  60   a ,  60   b  and the movable walls  822  are displaced by the reciprocating rotation of the movable body  30  caused by the resonance to drive the pump units  80  ( 80   a ,  80   b ). Thus, it is possible to further reduce the thickness of the pump  1  as well as increase an output of the pump  1 , thereby ensuring the desired pressure and the desired flow rate. 
     Further, in the present embodiment, the coil core portion  62   a  corresponding to the magnet  70   a  located on the one side of the movable body  30  constitutes the magnetic circuit with one coil. Thus, it is possible to reduce the cost of the pump  1 . 
     Second Embodiment 
       FIG.  14    is an external perspective view of a pump according to a second embodiment of the present invention.  FIG.  15    is a planar view the pump according to the second embodiment of the present invention in a state that a cover of the pump is omitted for the explanation.  FIG.  16    is an exploded perspective view of the pump according to the second embodiment of the present invention.  FIG.  17    is a perspective view of a coil core portion in the pump according to the second embodiment of the present invention.  FIG.  18    is a perspective view of a movable body in the pump according to the second embodiment of the present invention.  FIG.  19    is a horizontal cross-sectional view showing an internal configuration of the pump according to the second embodiment of the present invention. 
     Entire Configuration of Pump  1 A 
     A pump  1 A has the same basic configuration as the basic configuration of the pump  1  corresponding to the first embodiment shown in  FIG.  1    except that the configuration of the magnetic circuit is modified. Thus, the same components are denoted by the same reference numbers and description for the same components will be omitted in the following description. 
     As shown in  FIGS.  14  to  16   , the pump  1 A of the present embodiment has the same basic configuration as the basic configuration of the pump  1  of the first embodiment except the number of poles of a magnet  70 A and the number of poles of a coil core portion  62 A are different from corresponding ones of the pump  1 . 
     The pump  1 A is configured so that a movable body  30 A is provided in a case  21 A of a fixed body  20 A which has a rectangular planar shape so as to freely perform reciprocating rotation around a shaft portion  40 A disposed at a center of the case  21 A. Four-pole magnets  70 A- 1 ,  70 A- 2  are respectively provided at both ends of the movable body  30 A which are disposed so as to be separated from each other in a longitudinal direction of the movable body  30 A perpendicular to an axial direction of the shaft portion  40 A. 
     On the other hand, coil core portions  62 A- 1 ,  62 A- 2  each having three core magnetic poles are provided in the case  21  and at positions respectively facing the magnets  70 A- 1 ,  70 A- 2  through an air gap and aligned along wall portions separated from each other in a longitudinal direction of the case  21 A. 
     The pump units  80   a ,  80   b  are provided along the extending direction of the movable body  30 A in the case  21 A so as to sandwich the movable body  30 A in the depth direction of the case  21 A. The movable walls  822  of the pump units  80   a ,  80   b  are respectively connected to the pressing portions  35  of the movable body  30 A which is configured in the same manner as the pressing portions  35  of the pump  1 . 
     Since the coil core portion  62 A- 1  and the coil core portion  62 A- 2  have the same configuration, only the configuration of the coil core portion  62 A- 1  will be described and the description for the coil core portion  62 A- 2  will be omitted. 
     As shown in  FIG.  17   , the coil core portion  62 A- 1  has a coil  50 A and the core portion  60 A having an E-shape. The coil  50 A is wound around a center protrusion of the core portion  60 A through a bobbin  65 A. The center protrusion of the core portion  60 A serves as a core magnetic pole  601 A. When the electrical current flows in the coil  50 A, a tip end portion of the center protrusion of the core portion  60 A serves as the core magnetic pole  601 A and core magnetic poles  602 A,  603 A connected to a base end portion of the core magnetic pole  601 A are magnetized with a magnetic pole different from a magnetic pole of the core magnetic pole  601 A. A peripheral surface of the tip end portion of the core magnetic pole  601 A is covered by a flange of the bobbin  65 A so that the core magnetic pole  601 A partially protrudes from the bobbin  65 A. 
     The core magnetic poles  601 A,  602 A,  603 A of the coil core portion  62 A- 1  are disposed in an arc track so as to face the magnet  70 A- 1 . The coil core portion  62 A- 2  which is configured similarly to the coil core portion  62 A- 1  is disposed with being separated from the coil core portion  62 A- 1  in the longitudinal direction of the case  21  so that core magnetic poles  601 A,  602 A,  603 A of the coil core portion  62 A- 2  face the magnet  70 A- 2 . 
     As shown in  FIG.  18   , the magnets  70 A- 1 ,  70 A- 2  are respectively fixed to the magnet fixing portions  326   a ,  326   b  on both end portions of the movable body main portion  32  in which the bearing portion  34  is provided at the center portion of the movable body main portion  32 . 
     Magnetic pole surfaces  72  of each of the magnets  70 A- 1 ,  70 A- 2  are disposed so as to have an outwardly protruding arc track and be separated from each other in the longitudinal direction perpendicular to the axis of the shaft portion  40 A. The core magnetic poles  601 A to  603 A of the core portions  60 A of the core portions  62 A- 1 ,  62 A- 2  respectively face the magnetic pole surfaces  72  of the magnets  70 A- 1 ,  70 A- 2 . 
     Each of the magnetic pole surfaces  72  of the magnets  70 A- 1 ,  70 A- 2  has different magnetic poles  721 A to  724 A arranged in the rotation direction so that different magnetic poles are alternately arranged. 
     Magnetic attraction force is generated between the magnet  70 A- 1  and the core portion  60 A of the coil core portion  62 A- 1  and between the magnet  70 A- 2  and the core portion  60 A of the coil core portion  62 A- 2  and thus the magnetic attraction force serves as a magnetic spring. Namely, in each of both end portions of the movable body  30 A separated from each other in the longitudinal direction, the magnetic spring due to the magnetic attraction force is generated. 
     With the above-described magnet springs due to the magnetic attraction force, the rotation of the movable body  30 A around the shaft portion  40 A is suppressed when the pump  1 A is in a non-energized state, that is in a normal state. More specifically, the core portions  60 A- 1 ,  60 A- 2  and the magnets  70 A- 1 ,  70 A- 2  attract each other due to the magnetic attraction force at a position where the center core magnetic poles  601 A of the core portions  60 A- 1 ,  60 A- 2  respectively face center portions of the two center magnetic poles  722 A,  723 A of the magnets  70 A- 1 ,  70 A- 2  attached to the movable body  30 A. 
     The magnetic attraction force is generated between the core portion  60 A- 1  and the magnet  70 A- 1  and between the core portion  60 A- 2  and the magnet  70 A- 2 . Since the two kinds of the magnetic attraction force generated in the longitudinal direction of the movable body  30  are generated on the same straight line in opposite directions through the shaft portion  40 A, the two kinds of the magnetic attraction force are canceled each other. 
     As shown in  FIG.  19   , in the pump  1 A, boundary surface positions (switching positions) between adjacent poles among the magnetic poles  721 A,  722 A,  723 A,  724 A of each of the magnet  70 A- 1 ,  70 A- 2  respectively coincide with center positions of the core magnetic poles  601 A to  603 A of the coil core portion  62 A in the arc track of the rotation direction. In the normal state, a position of the movable body  30 A for setting the above-described positional relationship is a rotation reference position. More specifically, the boundary surface position (switching positions) between the magnetic pole  721 A,  722 A faces the center position of the core magnetic pole  602 A in the arc track of the rotation direction of the movable body  30 . Similarly, the boundary surface position (switching positions) between the magnetic pole  722 A,  723 A faces the center position of the core magnetic pole  601 A in the arc track of the rotation direction of the movable body  30 . Further, the boundary surface position (switching positions) between the magnetic pole  723 A,  724 A faces the center position of the core magnetic pole  603 A in the arc track of the rotation direction of the movable body  30 . 
       FIG.  20    is a view showing a magnetic circuit configuration of the pump according to the second embodiment of the present invention. In this regard, only the magnetic circuit provided by the coil core portion  62 A- 1  and the magnet  70 A- 1  will be described with reference to  FIG.  20    and description for the magnetic circuit provided by the coil core portion  62 A- 2  and the magnet  70 A- 2  will be omitted. 
     Magnet  70 A 
     It is assumed that the magnet  70 A- 1  has four magnetic poles on the magnetic pole surface  72  facing the core portion  62 A- 1  and these four magnetic poles are aligned in the rotation direction so that different polarities are alternately arranged. 
     In the magnet  70 A- 1  (sometimes referred by “ 70 A”) shown in  FIG.  20   , the center two magnetic poles  722 A,  723 A are respectively the S pole and the N pole and the magnetic poles  721 A,  724 A sandwiching the center magnetic poles  722 A,  723 A are respectively the N pole and the S pole. Further, the magnetic poles  721 A,  722 A,  723 A,  724 A face the core magnetic poles  601 A,  602 A,  603 A of the core magnetic pole  601 A of the coil core portion  62 A- 1  (sometimes referred by “ 62 A”). 
     The electrical current is supplied to the coil  50 A of the coil core portion  62 A to excite the core portion  60 A so that the core magnetic pole  601 A which is the center protrusion of the core portion  60 A is magnetized with the N pole and the core magnetic poles  602 A,  603 A of the core portion  60 A is magnetized with the S pole. 
     As shown in  FIG.  20   , the magnetic poles  722 A,  723 A of the magnet  70 A facing the core magnetic pole  601 A are respectively the S pole and the N pole. The magnetic pole  722 A which is the S pole attracts the core magnetic pole  601 A which is the N pole due to the magnetic attraction force and repels the core magnetic pole  723 A which is the N pole. 
     Further, since the magnetic pole  721 A of the magnet  70 A is the N pole, the magnetic attraction force is generated between the magnetic pole  721 A and the core magnetic pole  602 A which is the S pole. The magnetic pole  724 A of the magnet  70 A which is the S pole repels the core magnetic pole  603 A which is the S pole. 
     Due to these actions, thrust force in the direction F1 is generated between the magnet  70 A and the coil core portion  62 A and thus the movable body  30 A is driven in the direction F1. 
     In the state that the electrical current is not supplied in the coil  50 A, the movable body  30 A is located at the rotation reference position, that is a neutral position of the reciprocation movement by the magnetic attraction force of the magnetic springs. 
     In addition, the electrical current is supplied to the coil  50 A in the opposite direction to reverse the polarity of the core portion  60 A. Namely, the center core magnetic pole  601 A of the core portion  60 A facing the magnet  70 A is magnetized with the S pole and the core magnetic poles  602 A,  603 A of the core portion  60 A are magnetized with the N pole. As a result, the magnet  70 A facing the core portion  60 A rotates in a direction opposite to the direction F1 (the direction −F1) and thus the movable body  30 A is driven in the direction −F1 which is directly opposite to the direction F1. 
     In the movable body  30 A, since the relationship between the magnet  70 A- 2  disposed on the opposite side of the magnet  70 A- 1  through the shaft portion  40 A and the coil core portion  62 A- 2  is a point-symmetrical configuration around the shaft portion  40 A with respect to the relationship between the magnet  70 A- 1  and the coil core portion  62 A- 1 . Thus, the thrust force in the direction F1 or the direction −F1 is also generated between the magnet  70 A- 2  and the coil core portion  62 A- 2  by the magnet  70 A- 2  and the coil core portion  62 A- 2 . 
     Thus, the movable body  30 A suitably performs the reciprocating rotation around the shaft portion  40 A due to the magnetic attraction force and the repelling force effectively generated in the magnetic circuits at both end portion of the movable body  30 . 
     The driving principle and the pump performance of the pump  1 A are the same as those of the pump  1  of the first embodiment indicated by the above equations (1), (2), (3), (4) and (5). 
     Similar to the first embodiment, when the direction of the electrical current supplied to the coil  50 A is changed in the vibration actuator  10  of the pump  1 A, the movable body  30 A including the magnets  70 A- 1 ,  70 A- 2  can perform the reciprocating movement (reciprocating vibration) in the vibration direction. 
     According to the above-described configuration, the movable body  30  is elastically supported by the magnetic spring of the magnetic circuit provided by the magnets  70 A- 1  and the core portion  60 A- 1  and the magnetic spring of the magnetic circuit provided by the magnet  70 A- 2  and the core portion  60 A- 2 . Further, the movable walls  822  are displaced by the reciprocating rotation of the movable body  30  caused by the resonance to drive the pump units  80   a ,  80   b  to suction the air into the sealed chambers  82  of the pump units  80   a ,  80   b  and discharge the air from the sealed chambers  82  of the pump units  80   a ,  80   b . In this regard, the pump units  80   a ,  80   b  of the present embodiment have the same configuration as the pump units  80   a ,  80   b  of the first embodiment. Thus, it is possible to further reduce the thickness of the pump  1 A as well as increase the output of the pump  1 A, thereby ensuring the desired pressure and the desired flow rate of the pump  1 A. 
     Further, in the magnetic circuits disposed at both end portions of the pump  1 A, the core portion  60 A of each magnetic circuit constitutes the three magnetic poles  601 A,  602 A,  603 A with one coil  50 A. A cost of this can be reduced, and thereby a cost of the pump  1 A can be reduced. Further, since the core portion  60 A has the three magnetic poles, the drive output can be increased more than the configuration in which the core portion  60 A has two magnetic poles. 
     Third Embodiment 
       FIG.  21    is an external perspective view of a pump according to a third embodiment of the present invention.  FIG.  22    is a horizontal cross-sectional view showing an internal configuration of the pump according to the third embodiment of the present invention.  FIG.  23    is an exploded perspective view of the pump according to the third embodiment of the present invention.  FIG.  24    is a perspective view of a coil core portion in the pump according to the third embodiment of the present invention.  FIG.  25    is a perspective view of a movable body in the pump according to the third embodiment of the present invention.  FIG.  26    is a view showing a magnetic circuit configuration of the pump according to the third embodiment of the present invention. 
     A pump  1 B of the present embodiment has the same configuration as the configuration of the pump  1  of the first embodiment shown in  FIG.  1    except that only the configuration of the magnetic circuit is modified. Thus, the same components are denoted by the same reference numbers and description for the same components will be omitted in the following description. 
     As shown in  FIGS.  21  to  26   , the pump  1 B has the same basic configuration as the basic configuration of the pump  1  of the first embodiment except the number of poles of a magnet  70 B and the number of poles of a coil core portion  62 B are different from corresponding ones of the pump  1 . 
     The pump  1 B is configured so that a movable body  30 B is provided in a case  21 B of a fixed body  20 B which has a rectangular planar shape so as to freely perform reciprocating rotation around a shaft portion  40 B disposed at a center of the case  21 B. Four-pole magnets  70 B- 1 ,  70 B- 2  are respectively provided at both end portions of the movable body  30 B which are disposed so as to be perpendicular to an axial direction of the shaft portion  40 B and are separated from each other in a longitudinal direction of the movable body  30 B. 
     On the other hand, coil core portions  62 B- 1 ,  62 B- 2  each having three core magnetic poles are provided in the case  21 B and at positions respectively facing the magnets  70 B- 1 ,  70 B- 2  through an air gap. The magnets  70 B- 1 ,  70 B- 2  are respectively disposed along wall portions of the case  21 B separated from each other in the longitudinal direction of the case  21 B. 
     The pump units  80   a ,  80   b  are provided in the case  21  along an extending direction of the movable body  30 B so as to sandwich the movable body  30 B in a depth direction of the case  21 B. The movable walls  822  of the pump units  80   a ,  80   b  are respectively connected to pressing portions  35  of the movable body  30 B which is configured in the same manner as the pressing portions  35  of the pump  1  or the pump  1 A. 
     Coil Core Portion  62 B 
     Since the coil core portion  62 B- 1  and the coil core portion  62 B- 2  have the same configuration, only the configuration of the coil core portion  62 B- 1  (sometimes referred to as “ 62 B”) will be described and description for the coil core portion  62 B- 2  will be omitted. 
     As shown in  FIG.  24   , the coil core portion  62 B- 1  has three coils  50 B and a core portion  60 B having an E-shape. The coil core portion  62 B- 1  is configured to have the same number of coils  50 B as the number of core magnetic poles of the core portion  60 B. 
     Namely, the coils  50 B are respectively wound around outer circumferences of three protrusions of the E-shaped core portion  60 B through bobbins  65 B. The three protrusions of the core portion  60 B serve as core magnetic poles. 
     When the electrical current flows in the coils  50 B of the coil core portion  62 B, tip end portions of the three protrusions of the core portion  60 B respectively serve as core magnetic poles  601 B to  603 B and the magnetic poles  601 B to  603 B are magnetized so as to have alternately different polarities aligned in the rotation direction of the movable body  30 B. In this regard, peripheral surfaces of the tip end portions of the three protrusions of the core portion  60 B serving as the core magnetic poles  601 B to  603 B are respectively covered by flanges of the bobbins  65 B. 
     The core magnetic poles  601 B,  602 B,  603 B of the coil core portion  62 B- 1  are disposed in an arc track so as to face the magnet  70 B- 1 . 
     The coil core portion  62 B- 2  which is configured similarly to the coil core portion  62 B- 1  is disposed so as to be point-symmetrical around the shaft portion  40 B with respect to the coil core portion  62 B- 1  with being separated from the coil core portion  62 B- 1  in the longitudinal direction of the case  21 B. Further, the coil core portion  62 B- 2  is disposed so that the core magnetic poles  601 B,  602 B,  603 B of the coil core portion  62 B- 2  face the magnet  70 B- 2 . 
     Magnet  70 B 
     As shown in  FIG.  25   , the magnets  70 B- 1 ,  70 B- 2  are respectively fixed to the magnet fixing portions  326   a ,  326   b  on both end portions of the movable body main portion  32  in which the bearing portion  34  is provided at the center portion of the movable body main portion  32 . 
     Magnetic pole surfaces  72  of the magnets  70 B- 1 ,  70 B- 2  are disposed so as to form an arc track outwardly protruding and are separated from each other in the longitudinal direction perpendicular to an axis of the shaft portion  40 B. The core magnetic poles  601 B to  603 B of the core portions  60 B of the coil core portions  62 B- 1 ,  62 B- 2  respectively face the magnets  70 B- 1 ,  70 B- 2 . Each of the magnetic pole surfaces  72  of the magnets  70 B- 1 ,  70 B- 2  has magnetic poles  721 B to  724 B arranged in the rotation direction so that different polarities are alternately arranged. 
     Magnetic attraction force is generated between the magnet  70 B- 1  and the core portion  60 B of the coil core portion  62 B- 1  and between the magnet  70 B- 2  and the core portion  60 B of the coil core portion  62 B- 2  and thus the magnetic attraction force functions as a magnetic spring. Namely, the magnetic spring due to the magnetic attraction force is generated at each of the end portions of the movable body  30 B separated from each other in the longitudinal direction. 
     Due to the magnetic spring due to the above-described magnetic attraction force, the rotation of the movable body  30 B around the shaft portion  40 B is suppressed when the pump  1 B is in the non-energized state, that is, in the normal state. More specifically, the core portions  60 B- 1 ,  60 B- 2  and the magnets  70 B- 1 ,  70 B- 2  attract each other due the magnetic attraction force at a position where the center core magnetic poles  601 B of the core portions  60 B of the coil core portions  602 B- 1 ,  62 B- 2  respectively face center portions of the two center magnetic poles  722 B,  723 B of the magnets  70 B- 1 ,  70 B- 2 . 
     The magnetic attraction force is generated between the core portion  60 B- 1  and the magnet  70 B- 1  and between the core portion  60 B- 2  and the magnet  70 B- 2 . Since the two kinds of the magnetic attraction force generated in the longitudinal direction of the movable body  30 B are generated on the same straight line in opposite directions with sandwiching the shaft portion  40 B, the two kinds of the magnetic attraction force cancel each other. 
     As shown in  FIG.  22   , in the pump  1 B, boundary surface positions (switching positions) between adjacent poles among the magnetic poles  721 B,  722 B,  723 B,  724 B of each of the magnet  70 B- 1 ,  70 B- 2  respectively coincide with center positions of the core magnetic poles  601 B to  603 B of the coil core portion  62 B in the arc track of the rotation direction. In the normal state, a position of the movable body  30 B for setting the above-described positional relationship is a rotation reference position. More specifically, the boundary surface position (switching positions) between the magnetic pole  721 B,  722 B faces the center position of the core magnetic pole  602 B in the arc track of the rotation direction of the movable body  30 B. Similarly, the boundary surface position (switching positions) between the magnetic pole  722 B,  723 B faces the center position of the core magnetic pole  601 B in the arc track of the rotation direction of the movable body  30 B. Further, the boundary surface position (switching positions) between the magnetic pole  723 B,  724 B faces the center position of the core magnetic pole  603 B in the arc track of the rotation direction of the movable body  30 B. 
       FIG.  26    is a view showing a magnetic circuit configuration of the pump according to the third embodiment of the present invention. In this regard, only the magnetic circuit provided by the coil core portion  62 B- 1  and the magnet  70 B- 1  will be described with reference to  FIG.  26    and description for the magnetic circuit provided by the coil core portion  62 B- 2  and the magnet  70 B- 2  will be omitted. 
     It is assumed that the magnet  70 B- 1  has four magnetic poles on the magnetic pole surface  72  facing the coil core portion  62 B- 1  and the four magnetic poles are aligned in the rotation direction so that different polarities are alternately arranged. 
     In the magnet  70 B- 1  (sometimes referred by “ 70 B”) shown in  FIG.  26   , the center two magnetic poles  722 B,  723 B are respectively the S pole and the N pole and the magnetic poles  721 B,  724 B sandwiching the center magnetic poles  722 B,  723 B are respectively the N pole and the S pole. Further, the magnetic poles  721 B,  722 B,  723 B,  724 B of the magnet  70 B- 1  face the magnetic poles  601 B,  602 B,  603 B of the coil core portion  62 B- 1  (sometimes referred by “ 62 B”). 
     The electrical current is supplied to each of the coils  50 B of the coil core portion  62 B to excite the core portion  60 B. In the core portion  60 B, winding directions of the coils  50 B, flow directions of the electrical current in the coils  50 B or the like are set so that the polarity of the core magnetic pole  601 B which is the center protrusion of the core portion  60 B is different from the polarities of the core magnetic poles  602 B,  603 B adjacent to the core magnetic pole  601 B on the both sides. For example, in the coil core portion  62 B shown in  FIG.  26   , the core magnetic pole  601 B which is the center protrusion of the core portion  60 B is magnetized with the N pole and the core magnetic poles  602 B,  603 B of the core portion  60 B are magnetized with the S pole. At this time, since the core magnetic poles  601 B,  602 B,  603 B are excited by the corresponding coils  50 B, it is possible to ensure a high driving output. 
     As shown in  FIG.  26   , the magnetic poles  722 B,  723 B of the magnet  70 B facing the core magnetic pole  601 B which is the N pole are respectively the S pole and the N pole. The magnetic pole  722 B which is the S pole attracts the core magnetic pole  601 B which is the N pole due to the magnetic attraction force and repels the magnetic pole  723 B which is the N pole. Further, since the magnetic pole  721 B of the magnet  70 B is the N pole, the magnetic attraction force is generated between the magnetic pole  721 B and the core magnetic pole  602 B which is the S pole. The magnetic pole  724 B of the magnet  70 B which is the S pole repels the core magnetic pole  603 B which is the S pole. 
     Due to these actions, thrust force in the direction F1 is generated between the magnet  70 B and the coil core portion  62 B and thus the movable body  30 B is driven in the direction F1. When the electrical current is not supplied in the coils  50 B, the movable body  30 B is located at the rotation reference position, that is a neutral position of the reciprocation movement by the magnetic attraction force of the magnetic springs. 
     In addition, the electrical current is supplied to the coils  50 B in the opposite direction to reverse the polarity of the core portion  60 B, that is, the center core magnetic pole  601 B of the core portion  60 B facing the magnet  70 B is magnetized with the S pole and the magnetic poles  602 B,  603 B are magnetized with the N pole. As a result, the magnet  70 B facing the core portion  60 B rotates in a direction opposite to the direction F1 (the direction −F1) and thus the movable body  30 B is driven in the direction −F1 which is directly opposite to the direction F1. 
     In the movable body  30 B, the relationship between the magnet  70 B- 2  and the coil core portion  62 B- 2  is point-symmetrical around the shaft portion  40 B with respect to the relationship between the magnet  70 B- 1  and the coil core portion  62 B- 1 . Thus, the relationship between the magnet  70 B- 2  and the coil core portion  62 B- 2  is the same as the relationship between the magnet  70 B- 1  and the coil core portion  62 B- 1 . Therefore, it is possible to cause thrust force in the direction F1 or the direction −F1 between the magnet  70 B- 2  and the coil core portion  62 B- 2  as with the case of the thrust force between the magnet  70 B- 1  and the coil core portion  62 B- 1 . As a result, the movable body  30 B suitably performs the reciprocating rotation around the shaft portion  40 B due to the magnetic attraction force and the repelling force effectively generated in the magnetic circuits at both end portions of the movable body  30 B. 
     The movable body  30 B of the pump  1 B including the magnets  70 B- 1 ,  70 B- 2  can perform the reciprocating movement (reciprocating vibration) in the vibration direction by changing the flow direction of the electrical current supplied in the coils  50 B as described above similarly to the first embodiment. In this regard, the driving principle and the pump performance of the pump  1 B are the same as those of the pump  1  of the first embodiment indicated by the above equations (1), (2), (3), (4) and (5). 
     Further, the movable body  30 B is elastically supported by the magnetic spring of the magnetic circuit provided by the magnet  70 B- 1  and the core portion  60 B- 1  and the magnetic spring of the magnetic circuit provided by the magnet  70 B- 2  and the core portion  60 B- 2 . Further, the movable walls  822  are displaced by the reciprocating rotation of the movable body  30 B caused by the resonance to drive the pump unit  80 . Thus, it is possible to further reduce the thickness of the pump  1 B as well as increase the output of the pump  1 B, thereby ensuring the desired pressure and the desired flow rate of the pump  1 B. 
     Further, since the coil core portions  62 B in the magnetic circuit of one side of the pump  1 B has the three coils  50 B, it is possible to disperse arrangement spaces for the coils  50 B than a case where the number of coils  50 B is one. As a result, it is possible to increase design flexibility of the coils and thus it is possible to increase the driving output of the pump  1 B and reduce the thickness of the pump  1 B. 
     Fourth Embodiment 
       FIG.  27    is an external perspective view of a pump according to a fourth embodiment of the present invention.  FIG.  28    is a perspective view showing an internal configuration of the pump according to the fourth embodiment of the present invention.  FIG.  29    is a horizontal cross-sectional view showing the internal configuration of the pump according to the fourth embodiment of the present invention.  FIG.  30    is an exploded perspective view of the pump according to the fourth embodiment of the present invention.  FIG.  31    is a perspective view of a coil core portion in the pump according to the fourth embodiment of the present invention.  FIG.  32    is a perspective view of a movable body in the pump according to the fourth embodiment of the present invention. 
     A pump  1 C has the same basic configuration as the configuration of the pump  1  of the first embodiment shown in  FIG.  1    except that only the configuration of the magnetic circuit is modified. Thus, the same components are denoted by the same reference numbers and description for the same components will be omitted in the following description. 
     The pump  1 C shown in  FIGS.  27  to  32    has the same basic configuration as the basic configuration of the pump  1  of the first embodiment except that the number of magnetic circuits constituted of a magnet  70 C and a coil core portion  62 C is one and the number of poles of the magnet  70 C and the number of poles of the coil core portion  62 C are different from corresponding ones of the pump  1 . 
     Entire Configuration of Pump  1 C 
     As shown in  FIG.  27    and  FIG.  28   , the pump  1 C is configured so that a movable body  30 C is provided in a case  21 C having a rectangular planar shape so as to freely perform reciprocating rotation (reciprocating pivotal movement) around a shaft portion  40 C disposed at a center of the case  21 C. The case  21 C constitutes a housing together with a cover  22 C for closing an opening of the case  21 C. 
     The shaft portion  40 C is provided in the case  21 C so as to be located on one of both end portions of the case  21 C in a longitudinal direction of the case  21 C. The movable body  30 C is provided in the case  21 C so as to extend a direction perpendicular to an axial direction of the shaft portion  40 C and freely perform the pivotal movement around the shaft portion  40 C. The bearing portion  34  through which the shaft portion  40 C is passed is provided on one end portion of the movable body  30 C. The magnet  70 C having two poles is provided on the other end portion of the movable body  30 C. 
     On the other hand, the coil core portion  62 C is provided in the case  21 C along a wall portion of the case  21 C located on one side of the longitudinal direction of the case  21 C. The coil core portion  62 C is disposed at a position facing the magnet  70 C through an air gap and has three core magnetic poles  601 C,  602 C,  603 C. 
     In addition, a pair of pump units  80 C having the same basic configuration as the configurations of the pump units  80   a ,  80   b  are provided in the case  21 C along the extending direction of the movable body  30 C. The pair of pump units  80 C are provided so as to sandwich the movable body  30 C in a depth direction of the case  21 C. The movable walls  822  of the pump units  80 C are respectively connected to pushers  351  of pressing portions  35  of the movable body  30 C which have the same configurations as the configurations of the pusher  351  of the pressing portion  35  of the pump  1 , the pump  1 A or the pump  1 B and displaced by the reciprocating rotation (pivotal movement) of the movable body  30 C. The air can be discharged from discharge portions  86 C by this displacement of the movable walls  822 . 
     Coil Core Portion  62 C 
     As shown in  FIG.  31   , the coil core portion  62 C has a coil  50 C and a core portion  60 C having an E-shape. The core portion  60 C has core magnetic poles  601 C to  603 C parallelly provided so as to protrude toward one direction from a rear surface portion  608  having a predetermined height, that is a height substantially equal to heights of the case  21 C and the movable body  30 C. In the present embodiment, each of the core magnetic poles  601 C to  603 C has a thickness (a length in the height direction) thinner than a thickness of the rear surface portion  608  and protrudes from a center portion in the height direction of the rear surface portion  608  toward the same direction. With this configuration, each of tip end surfaces of the core magnetic poles  601 C to  603 C is formed to be long in the rotation direction of the movable body  30 C and to be in an arc-shape which concaves on the tip side. In the coil core portion  62 C, one coil  50 C is wound around the core magnetic pole  601 C which is a center protrusion of the core portion  60 C through a bobbin  65 C. 
     Namely, in the coil core portion  62 C, the electrical current is supplied in the coil  50 C to magnetize a tip end portion of the core magnetic pole  601 C located in the coil  50 C. At this time, a polarity of the core magnetic pole  601 C is different from polarities of the core magnetic poles  602 C,  603 C sandwiching the core magnetic pole  601 C from both sides. As a result, the core magnetic poles  601 C to  603 C which are the protrusions of the core portion  60 C are magnetized so as to have alternately different polarities arranged in the rotation direction of the movable body  30 C. A peripheral surface of the tip end portion of the core magnetic pole  601 C is covered with a flange of the bobbin  65 C. 
     The core magnetic poles  601 C,  602 C,  603 C of the coil core portion  62 C are arranged in an arc track so as to face the magnet  70 C. 
     Magnet  70 C 
     As shown in  FIG.  32   , the bearing portion  34  is provided on one end portion of the movable body main portion  32 C. The magnet  70 C is fixed to a magnet fixing portion  326 C formed on the other end portion of the movable body main portion  32 C for passing the shaft portion  40 C. 
     The magnetic pole surface  72 C of the magnet  70 C is provided on the other end portion of the movable body main portion  32 C so as to have an arc shape protruding toward the outside and faces the core magnetic poles  601 C to  603 C of the core portion  60 C. The magnetic pole surface  72 C of the magnet  70 C has different magnetic poles  721 C,  722 C arranged in the rotation direction of the movable body  30 C. 
     The magnet  70 C is disposed at a position so that a boundary surface position (switching position) between the magnetic poles  721 C,  722 C of the magnet  70 C is located on an axis line of an extending direction (longitudinal direction) of the magnet  70 C and the boundary surface position (switching position) between the magnetic poles  721 C,  722 C of the magnet  70 C overlaps with a center of the center core magnetic pole  601 C of the coil core portion  62  in the rotation direction. 
     Magnetic attraction force is generated between the magnet  70 C and the core portion  60 C of the coil core portion  62 C and thus the magnetic attraction force serves as a magnetic spring. Namely, the magnetic spring due to the magnetic attraction force is generated at the other end portion of the movable body  30 C in the longitudinal direction thereof. 
     Due to the magnetic spring provided by the magnet  70 C and the core portion  60 C of the coil core portion  62 C, the rotation of the movable body  30 C around the shaft portion  40 C is suppressed when the pump  1 C is in the non-energized state, that is, in the normal state. More specifically, the core portion  60 C and the magnet  70 C attract each other due to the magnetic attraction force at a position where center portions of the two center magnetic poles  721 C,  722 C of the magnet  70 C face the center core magnetic pole  601 C of the core portions  60 C. 
     Since the magnet  70 C and the core portions  60 C attract each other due to the magnetic attraction force, the movable body  30 C is held in a horizontal state at a reference position which is a center position of an oscillation range of the reciprocating rotation (pivotal movement) of the movable body  30 C, i.e., at the center (rotation reference position) of the vibration range of the oscillation movement around the shaft portion  40 C. 
     As shown in  FIG.  29   , the magnet  70 C and the coil core portion  62 C are provided in the case  21 C so that the boundary surface position (switching position) between the magnetic poles  721 C,  722 C of the magnet  70 C overlaps the center of the rotational direction of the center core magnetic pole  601 C of the coil core portion  62 C in the longitudinal direction. This position of the movable body  30 C for achieving the above-described positional relationship is the rotation reference position in the normal condition of the movable body  30 C. The movable body  30 C can perform the reciprocating rotation (reciprocating pivotal movement) from this position in opposite directions of the depth direction of the case  21 , that is in directions perpendicular to both of the longitudinal direction and the axial direction of the case  21 C by the same distance. 
       FIG.  33    is a view showing a magnetic circuit configuration of the pump according to the fourth embodiment of the present invention. 
     The magnet  70 C has two different polarities alternately arranged in the rotation direction on a magnetic pole surface  72 C facing the coil core portion  62 C. In the magnet  70 C shown in  FIG.  33   , the two magnetic poles  721 C,  722 C are respectively the S pole and the N pole and face the magnetic poles of the coil core portion  62 C. 
     The electrical current is supplied to the coil  50 C of the coil core portion  62 C to excite the core portion  60 C. At this time, a winding direction of the coil  50 C, a flow direction of the electrical current supplied in the coil  50 C or the like are set so that the polarity of the core magnetic pole  601 C which is the center protrusion of the core portion  60 C is different from the polarities of the core magnetic poles  602 C,  603 C adjacent to the core magnetic pole  601 C on the both sides. 
     For example, in the coil core portion  62 C shown in  FIG.  33   , the center core magnetic pole  601 C of the core portion  60 C is magnetized with the N pole and the core magnetic poles  602 C,  603 C of the core portion  60 C are magnetized with the S pole. At this time, the core magnetic pole  601 C is magnetized by the coil  50 C. 
     As shown in  FIG.  33   , the magnetic poles  721 C,  722 C of the magnet  70 C facing the core magnetic pole  601 C which is the N pole are respectively the S pole and the N pole. The magnetic pole  721 C which is the S pole attracts the core magnetic pole  601 C which is the N pole due to the magnetic attraction force and the magnetic pole  722 C which is the N pole repels the core magnetic pole  601 C which is the N pole. 
     Due to these actions, thrust force in the direction F1 is generated between the magnet  70 C and the coil core portion  62 C and thus the movable body  30 C is driven in the direction F1. 
     When the electrical current is not supplied in the coil  50 C, the movable body  30 C is located at the rotation reference position, that is a neutral position of the reciprocating movement by the magnetic spring provided by the magnet  70 C and the coil core portion  62 C. 
     In addition, the electrical current is supplied to the coil  50 C in the opposite direction to reverse the polarity of the core portion  60 C, that is, the center core magnetic pole  601 C of the core portion  60 C facing the magnet  70 C is magnetized with the S pole and the core magnetic poles  602 C,  603 C are magnetized with the N pole. As a result, the magnet  70 C facing these core magnetic poles  601 C,  602 C,  603 C rotates in a direction opposite to the direction F1 (the direction −F1) and thus the movable body  30 C is driven in the direction −F1 which is directly opposite to the direction F1. 
     Thus, the movable body  30 C suitably perform the reciprocating rotation (pivotal movement) around the shaft portion  40 C due to the magnetic attraction force and the repelling force effectively generated in the magnetic circuit provided by the magnet  70 C and the coil core portion  62 C at the other end portion of the movable body  30 C. 
     As described above, by changing the direction of the electrical current supplied to the coil  50 C in the pump  1 C, the movable body  30 C including the magnet  70 C can perform the reciprocating movement (reciprocating vibration) in the vibration direction similarly to the first embodiment. In this regard, the driving principle and the pump performance of the pump  1 C are the same as those of the pump  1  of the first embodiment indicated by the above equations (1), (2), (3), (4) and (5). 
     In the magnetic circuit of the pump  1 C, the core portion  60 C uses the coil  50 C to provide the three core magnetic poles  601 C,  602 C,  603 C. As described above, the pump  1 C has a configuration in which the magnetic spring of the magnetic circuit provided by the magnet  70 C and the core portion  60 C elastically support the movable body  30 C which can perform the reciprocating rotation (pivotal movement) due to the resonance. Thus, it is possible to further downsize the pump  1 C and reduce the cost of manufacturing the pump  1 C by reducing the number of parts, and thereby increasing the drive output of the pump  1 C. 
     Fifth Embodiment 
       FIG.  34    is an external perspective view of a pump according to a fifth embodiment of the present invention.  FIG.  35    is an exploded perspective view of the pump according to the fifth embodiment of the present invention.  FIG.  36    is a horizontal cross-sectional view showing an internal configuration of the pump according to the fifth embodiment of the present invention.  FIG.  37    is an exploded perspective view of a pump unit in the pump according to the fifth embodiment of the present invention.  FIG.  38    is a view showing an air flow path of the pump unit in the pump according to the fifth embodiment of the present invention. Each of  FIG.  39 A  and  FIG.  39 B  is a schematic view which is referred to explain reciprocating rotational movement of a movable body in the pump unit according to the fifth embodiment of the present invention. 
     A pump  1 D of the present embodiment has the same basic configuration as the basic configuration of the pump  1  of the first embodiment shown in  FIG.  1    except that a fixed body includes magnets and a movable body includes a coil core portion. Thus, the same components are denoted by the same reference numbers and description for the same components will be omitted in the following description. 
     Entire Configuration of Pump  1 D 
     The pump  1 D shown in  FIGS.  34  to  39    has the same basic configuration as the basic configuration of the pump  1  of the first embodiment except that a fixed body  20 D includes magnets  70 D ( 70 D- 1 ,  70 D- 2 ) and a movable body  30 D includes a coil core portion  62 D. 
     As shown in  FIG.  34    and  FIG.  36   , the fixed body  20 D of the pump  1 D of the present embodiment includes a case  21 D having a rectangular planar shape, a cover  22 D for covering an opening portion of the case  21 D opened toward the upper side, a pair of yokes  73  respectively provided on inner surfaces of wall portions of the case  21 D separated from each other in a longitudinal direction of the case  21 D, and a pair of magnets  70 D- 1 ,  70 D- 2  respectively provided on the pair of yokes  73 . Further, a pair of pump units  80 D are respectively provided on inner surfaces of wall portions of the case  21 D separated from each other in a depth direction of the case  21 D. Thus, the pair of pump units  80 D are respectively disposed at positions sandwiching the movable body  30 D in the depth direction of the case  21 D, that is a reciprocating rotation (pivotal movement) direction of the movable body  30 D with being separated from each other. 
     A shaft portion  40 D is provided in the case  21 D so as to extend from a portion on a bottom surface of the case  21 D near to one of longitudinal direction end portions of the case  21 D toward a height direction of the case  21 D. By passing the shaft portion  40 D through the bearing portion  34  of the movable body  30 D, the movable body  30 D can be supported in the case  21 D so as to freely perform reciprocating rotation (pivotal movement) around the shaft portion  40 D. 
     The pair of yokes  73  are respectively provided on the inner surfaces of the wall portions of the case  21 D separated from each other in the longitudinal direction of the case  21 D. Each of the pair of yokes  73  is formed of magnetic material and has a substantially rectangular parallelepiped entire shape including a flat surface facing the wall portion of the case  21  and an arc-shaped surface on the opposite side of the flat surface. Each yoke  73  is fixed on the inner surface of the wall portion of the case  21 D so that the flat surface faces the inner surface of the wall portion of the case  21 D and the arc-shaped surface is directed toward the inner side. Thus, the arc-shaped surfaces of the pair of yokes  73  respectively provided on the inner surfaces of the wall portion of the case  21 D separated from each other in the longitudinal direction of the case  21 D face each other through the magnets  70 D- 1 ,  70 D- 2  and the movable body  30 D as shown in  FIG.  36   . 
     Magnet  70 D 
     As shown in  FIG.  36   , each of the magnets  70 D- 1 ,  70 D- 2  has an arc shape corresponding to the arc-shaped surfaces of the pair of yokes  73 . The magnets  70 D- 1 ,  70 D- 2  are respectively provided on the arc-shaped surfaces of the pair of yokes  73 . Each of the magnets  70 D- 1 ,  70 D- 2  includes two magnetic poles  721 D,  722 D on its magnetic pole surface  72 D facing the movable body  30 D. The two magnetic poles  721 D,  722 D are aligned along the rotation (pivotal movement) direction of the movable body  30 D and has different polarities. In one example shown in  FIGS.  39 A and  39 B , the magnetic pole  721 D is the S pole and the magnetic pole  722 D is the N pole. As described above, the fixed body  20 D of the pump  1 D of the present invention includes the magnets  70 D- 1 ,  70 D- 2  unlike the pumps  1 ,  1 A,  1 B,  1 C of the first to fourth embodiments. 
     Movable Body  30 D 
     In the pump  1 D of the present embodiment, the movable body  30 D is formed of magnetic material (ferromagnetic material) and also serves as the coil core portion  62 D. As shown in  FIGS.  35  and  36   , the movable body  30 D includes a movable body main portion  32 D having an arm portion  324   a , a pressing portion  35  provided on the arm portion  324   a , a bobbin  65 D provided on a tip end portion of the arm portion  324   a , and a coil  50 D which is wound around the bobbin  65 D and to which an electrical current is supplied from a power supply unit. In this regard, the pressing portion  35  of the present embodiment has the same configuration as the configuration of the pressing portion  35  of each of the pumps  1 ,  1 A,  1 B,  1 C of the first to fifth embodiments described above. 
     By passing the shaft portion  40 D through the bearing portion  34 , the movable body  30 D can be supported in the case  21 D so as to freely perform the reciprocating rotation (pivotal movement). The movable body main portion  32 D includes the center opening portion  322  (see  FIG.  3   ) in which the bearing portion  34  is fitted, and the arm portion  324   a  provided so as to extend from the movable body main portion  32 D toward a direction perpendicular to an axial direction of the shaft portion  40 D. Both of the movable body main portion  32 D and the arm portion  324   a  are formed of magnetic material (ferromagnetic material) and integrated with each other. Thus, when the electrical current is supplied in the coil  50 D provided so as to surround the tip end portion of the arm portion  324   a  through the bobbin  65 D, both end portions of the movable body  30 D are magnetized with different polarities. As described above, in the pump  1 D of the present embodiment, the arm portion  324   a  of the movable body  30 D serves as a core portion  60 D around which the coil  50  is wound and the movable body  30 D serves as the coil core portion  62 D. Further, when the electrical current is supplied to the coil  50 D, both end portions of the movable body  30 D are magnetized and thus serve as a core magnetic pole of the coil core portion  62 D. Thus, it can be considered that the movable body  30 D of the pump  1 D of the present embodiment includes the coil core portion  62 D. Further, it can be considered that the coil core portion  62 D is provided on the tip end portion of the arm portion  324   a.    
     The movable body  30 D is provided in the case  21 D so that the one end portion of the movable body  30 D faces the magnet  70 D- 1  through an air gap in the direction perpendicular to the axial direction (rotational axis) of the shaft portion  40 D and the other end portion of the movable body  30 D faces the magnet  70 D- 2  through an air gap in the direction perpendicular to the axial direction (rotational axis) of the shaft portion  40 D. Further, since both of the movable body main portion  32 D and the arm portion  324   a  are formed of the magnetic material (ferromagnetic material), magnetic circuits are formed between the one end portion of the movable body  30 D and the magnet  70 D- 1  and between the other end portion of the movable body  30 D and the magnet  70 D- 2 .  FIG.  39 A  shows a state that the electrical current is supplied to the coil  50 D to magnetize the one end portion of the movable body  30 D facing the magnet  70 D- 1  with the S pole and magnetize the other end portion of the movable body  30 D facing the magnet  70 D- 2  with the N pole. Further,  FIG.  39 B  shows a state that the electrical current is supplied to the coil  50 D in an opposite direction to reverse the polarities of both end portions of the movable body  30 D, namely to magnetize the one end portion of the movable body  30 D facing the magnet  70 D- 1  with the N pole and magnetize the other end portion of the movable body  30 D facing the magnet  70 D- 2  with the S pole. As shown in  FIGS.  39 A and  39 B , the magnetic circuit is provided by the one end portion of the movable body  30 D serving as the core magnetic pole of the coil core portion  62 D and the magnet  70 D- 1 . Similarly, the other magnetic circuit is provided by the other one end portion of the movable body  30 D serving as the core magnetic pole of the coil core portion  62 D and the magnet  70 D- 2 . 
     Pump Unit  80 D 
     As shown in  FIG.  37   , each of the pair of pump units  80 D includes a base  801 , a diaphragm portion  802 , a cylinder portion  803 , valves  84   a ,  84   b , a valve cover portion  805 , and a flow path forming portion  807 . The base  801  has one opening portion. An insertion portion  822   a  of the diaphragm portion  802  is passed through this opening portion from the rear side and thus the diaphragm portion  802  is disposed in a state that the insertion portion  822   a  protrudes toward the front side. 
     The diaphragm portion  802  includes one insertion portion  822   a  and one movable wall  822 . A chamber forming portion  824  of the cylinder portion  803  is provided on the rear side of the movable wall  822  which has flexibility and can be elastically deformed. The diaphragm portion  802  and the cylinder portion  803  are attached to each other so that a sealed chamber  82  which is a sealed space is formed by the movable wall  822  of the diaphragm portion  802  and the chamber forming portion  824  of the cylinder portion  803 . 
     As shown in  FIG.  38   , the valve  84   a  is provided so as to close a flow path for communicating between a suction portion  83 D and the sealed chamber  82  defined by the movable wall  822  and the chamber forming portion  824 . When pressure in the sealed chamber  82  decreases to a predetermined threshold value, the valve  84   a  is opened and thus the air is suctioned into the sealed chamber  82  through the suction portion  83 D. When the pressure in the sealed chamber  82  exceeds another predetermined value, the valve  84   a  is closed and thus the suction of the air into the sealed chamber  82  through the suction portion  83 D is stopped. The valve  84   b  is provided so as to close a flow path for communicating between a discharge portion  86 D and the sealed chamber  82  defined by the movable wall  822  and the chamber forming portion  824 . When the pressure in the sealed chamber  82  exceeds a predetermined threshold value, the valve  84   b  is opened and thus the air in the sealed chamber  82  is discharged toward the outside through the discharge portion  86 D. When the pressure in the sealed chamber  82  decreases to another threshold value, the valve  84   b  is closed and thus the discharge of the air from the sealed chamber  82  toward the outside through the discharge portion  86 D. 
     Referring back to  FIG.  37   , the valve cover portion  805  is attached to the cylinder portion  803  from the rear side of the cylinder portion  803 . Further, the flow path forming portion  807  is attached to the valve cover portion  805  from the rear side of the valve cover portion  805 . The suction portion  83 D for suctioning the air into the sealed chamber  82  and the discharge portion  86 D for discharging the air from the sealed chamber  82  are formed in the flow path forming portion  807 . The suction portion  83 D and the discharge portion  86 D are formed so as to protrude from the rear side of the flow path forming portion  807  toward the outside. As shown in  FIG.  34   , the suction portions  83 D and the discharge portions  86 D protrude from the short-side wall portion of the case  21 D of the pump  1 D toward the outside. 
       FIG.  38    shows the flow path for suctioning the air into the sealed chamber  82  through the suction portion  83 D and the flow path for discharging the air in the sealed chamber  82  through the discharge portion  86 D. Arrowed lines in  FIG.  38    represent the flow of the air. When the valve  84   a  is opened, the air is suctioned into the sealed chamber  82  through the suction portion  83 D. On the other hand, when the valve  84   b  is opened, the air in the sealed chamber  82  is discharged toward the outside through the discharge portion  86 D. Similar to the above-described pumps  1 ,  1 A,  1 B,  1 C of the first to fourth embodiments, the pusher  351  of the pressing portion  35  is connected to the insertion portion  822   a  of the sealed chamber  82 . Thus, when the movable body  30 D performs the reciprocating rotation (pivotal movement), the pressure in the sealed chamber  82  changes according to the reciprocating rotation movement (pivotal movement) of the movable body  30 D, and thereby the suction of the air into the sealed chamber  82  and the discharge of the air from the sealed chamber  82  toward the outside are performed. 
     Next, the reciprocating rotation movement of the movable body  30 D in the pump  1 D will be described with reference to  FIGS.  39 A and  39 B .  FIG.  39 A  shows the state that the electrical current is supplied to the coil  50 D to magnetize the one end portion of the movable body  30 D facing the magnet  70 D- 1  with the S pole and magnetize the other end portion of the movable body  30 D facing the magnet  70 D- 2  with the N pole. As shown in  FIG.  39 A , the one end portion of the movable body  30 D which is the S pole repels the magnetic pole  721 D of the magnet  70 D- 1  which is the S pole and attracts the magnetic pole  722 D of the magnet  70 D- 1  which is the N pole. As a result, thrust force for rotating (pivotally rotating) the movable body  30 D in the direction F1 is generated at the one end portion of the movable body  30 D. On the other hand, the other end portion of the movable body  30 D which is the N pole attracts the magnetic pole  721 D of the magnet  70 D- 2  which is the S pole and repels the magnetic pole  722 D of the magnet  70 D- 2  which is the N pole. As a result, the thrust force for rotating (pivotally rotating) the movable body  30 D in the direction F1 is also generated at the other end portion of the movable body  30 D. 
       FIG.  39 B  shows the state that the electrical current is supplied to the coil  50 D in the opposite direction to reverse the polarities of both end portions of the movable body  30 D, namely to magnetize the one end portion of the movable body  30 D facing the magnet  70 D- 1  with the N pole and magnetize the other end portion of the movable body  30 D facing the magnet  70 D- 2  with the S pole. As shown in  FIG.  39 B , the one end portion of the movable body  30 D which is the N pole attracts the magnetic pole  721 D of the magnet  70 D- 1  which is the S pole and repels the magnetic pole  722 D of the magnet  70 D- 1  which is the N pole. As a result, thrust force for rotating (pivotally rotating) the movable body  30 D in the direction −F1 is generated at the one end portion of the movable body  30 D. On the other hand, the other end portion of the movable body  30 D which is the S pole repels the magnetic pole  721 D of the magnet  70 D- 2  which is the S pole and attracts the magnetic pole  722 D of the magnet  70 D- 2  which is the N pole. As a result, the thrust force for rotating (pivotally rotating) the movable body  30 D in the direction −F1 is also generated at the other end portion of the movable body  30 D. With this configuration, the movable body  30 D can suitably perform the reciprocating rotation (pivotal movement) around the shaft portion  40 D in the case  21 D by supplying an alternating electrical current having a proper frequency into the coil  50 D. 
     As described above, by changing the direction of the electrical current supplied to the coil  50 D in the pump  1 D, the movable body  30 D including the coil core portion  62 D can perform the reciprocating movement (reciprocating vibration) in the vibration direction similarly to the first embodiment. In this regard, the driving principle and the pump performance of the pump  1 D are the same as those of the pump  1  of the first embodiment indicated by the above equations (1), (2), (3), (4) and (5). Further, since the coil  50 D is provided on the arm portion  324   a  of the movable body  30 D which performs the reciprocating rotation (pivotal movement), the vibration actuator  10  of the present embodiment, is a moving coil-type actuator. On the other hand, since the magnet  70 ,  70 A,  70 B or  70 C is provided on the movable body  30 ,  30 A,  30 B or  30 C in the above-described first to fourth embodiment, the vibration actuator  10  of each of the first to fourth embodiments is a moving magnet-type actuator. 
     The above-described pump of each embodiment may be provided in a wearable device or the like to measure blood pressure. Further, a pump device may be a sphygmomanometer in which the pump is provided integrally with the cuff. Further, the pump may be used as an air pump provided in a water cistern. The power supply unit for the pump device may be driven by a battery such as a dry-cell battery. In this case, it is noted that the pump device should have a configuration in which an electrical current of the dry-cell battery should be converted to an electrical current for driving the pump, that is a direct electrical current is converted to an alternating electrical current. 
     Sixth Embodiment 
       FIG.  40    is a view schematically showing an air supply device according to a sixth embodiment of the present invention. A pump device shown in  FIG.  40    is, for example, a sphygmomanometer  10 E as an air supply device. 
     The sphygmomanometer  10 E includes a cuff  102 , a tube  5  for supplying air into the cuff  102 , and a drive unit  104 . 
     The drive unit  104  includes a drive control part  106  and a resonant pump  1 E which can be any one of the pumps  1 A to  1 D of the embodiments. A driving signal converted for driving the resonant pump  1 E is inputted from the drive control part  106 . 
     The drive control part  106  is connected to the resonant pump  1 E and a circuit for driving the vibration actuator  10  is provided in the drive control part  106 . The drive control part  106  supplies the driving signal to the resonant pump  1 E. 
     The resonant pump  1 E is driven according to the driving signal inputted from the drive control part  106 . More specifically, the tube  5  is connected to the discharge portion  86  of the resonant pump  1 E and the movable body  30  of the resonant pump  1 E vibrates to drive the pump units  80 . As a result, it is possible to suitably supply the air into the cuff of the sphygmomanometer or the like. 
     With this configuration, it is possible to secure a desired pressure and a desired flow rate with making the sphygmomanometer  10 D thinner. The embodiments of the present invention have been described in the above description. The above description exemplifies the preferred embodiments of the present invention and the scope of the present invention is not limited thereto. In other words, the configuration of the device and the shape of each part are provided as only examples and it would be obvious that various modifications and additions to these examples are possible within the scope of the present invention. 
     INDUSTRIAL APPLICABILITY 
     The pump and the air supply device according to the present invention have the effect of ensuring the high discharge pressure and the high flow rate and can further reduce the thickness thereof. For example, the pump and the air supply device are useful for a wearable device to which a high output and a thin thickness are desired. For the reasons stated above, the present invention has industrial applicability.