Patent Publication Number: US-2019181708-A1

Title: Rotary electrical machine

Description:
TECHNICAL FIELD 
     The present disclosure relates to a rotary electrical machine including one or more magnets and one or more through holes. 
     BACKGROUND ART 
     For example, PTL 1 discloses a technique relating to a rotor in a permanent magnet-type rotary machine intended to enhance the heat dissipation of spacers to improve the cooling efficiency of permanent magnets. This rotor includes a non-magnetic press plate on both end surfaces of a boss to suppress the axial displacement of the permanent magnets and the spacers. The rotor also has ventilation holes that penetrate through the press plates and the spacers in the axial direction. 
     CITATION LIST 
     Patent Literature 
     [PTL 1] JP 3480800 B 
     SUMMARY OF THE INVENTION 
     [Technical Problem] 
     However, when the technique described in PTL 1 is applied to a rotary electrical machine, the press plates disturb the outside air at the entrances to the ventilation holes during rotation. Accordingly, an air-curtain effect is produced at the entrances to the ventilation holes to block the flow of air into the ventilation holes. The air-curtain effect becomes more enhanced with increase in the rotation speed of the rotor. 
     The ventilation holes are provided in the spacers. Each of the spacers has a region with a small inter-electrode width to suppress leakage flux between magnets that are arranged circumferentially at the outer peripheral portion of the rotor. Each of the ventilation holes cannot have a large cross-sectional area. Accordingly, the flow rates of air into the ventilation holes for cooling are suppressed. 
     Due to the air-curtain effect and the cross-sectional areas of the ventilation holes described above, the air hardly passes through the ventilation holes even when the rotor rotates. As a result, the cooling effect cannot be obtained. 
     The present disclosure provides a rotary electrical machine implementing the following matters. A first object of the present disclosure is to introduce actively a refrigerant into a through hole without influence of the air-curtain effect. A second object of the present disclosure is to ensure the large cross-sectional area of the through hole to enhance the cooling effect. 
     Solution to Problem 
     A first rotary electrical machine as an aspect of the technique of the present disclosure has: a rotor ( 13 ) that includes one or more magnet ( 13   a ) and one or more through holes ( 13   b ) penetrating in an axial direction; and a stator ( 11 ) that is opposed to the rotor. The first rotary electrical machine has an introduction member ( 16 ) that communicates partially or entirely with the one or more penetration holes and introduces a refrigerant ( 18   a,    18   b ). The introduction member includes a protrusion portion ( 16   b ), an intake portion ( 16   a ), and a communication portion ( 16   c ). The protrusion portion protrudes axially from an end surface of the rotor. The intake portion is provided at one end of the protrusion portion and is opened toward the rotational direction of the rotor to take in the refrigerant. The communication portion is provided at the other end of the protrusion portion and communicates with the opening. As described above, in the first rotary electrical machine, the introduction member protrudes axially from the end surface of the rotor and is opened toward the rotational direction of the rotor. Accordingly, in the first rotary electrical machine, it is possible to introduce actively the refrigerant to cool the magnet without influence of the air-curtain effect. 
     In a second rotary electrical machine as an aspect of the technique of the present disclosure, the magnet is arranged closer to an outer radial side than to the through hole. 
     Accordingly, the refrigerant passing through the through hole is subjected to centrifugal action and moves in such a manner as to be attracted to the outer radial side on which the magnet is arranged. Accordingly, in the second rotary electrical machine, the magnet can be cooled efficiently. 
     In a third rotary electrical machine as an aspect of the technique of the present disclosure, the through hole communicates with a storage hole storing the magnet and has a barrier function to prevent magnetic leakage of the magnet. Accordingly, in the third rotary electrical machine, the refrigerant can cool not only the wall surface of the through hole but also the side surface of the magnet. 
     In a fourth rotary electrical machine as an aspect of the technique of the present disclosure, the introduction member is scoop-shaped. Accordingly, in the fourth rotary electrical machine, the refrigerant subjected to turning force can be passed into the through hole without waste. As a result, in the fourth rotary electrical machine, the magnet can be cooled effectively. 
     In a fifth rotary electrical machine as an aspect of the technique of the present disclosure, the intake portion is positioned closer to the outer radial side than to the communication portion. Accordingly, in the fifth rotary electrical machine, the amount of rotational movement becomes larger with increasing proximity to the outer radial side to take in a larger amount of refrigerant (increase the amount of refrigerant). As a result, in the fifth rotary electrical machine, the cooling efficiency is improved. 
     In a sixth rotary electrical machine as an aspect of the technique of the present disclosure, the intake portion includes an outer radial-side wall portion ( 16   ae ) and an inner radial-side wall portion ( 16   ai ) that extend axially from the end surface of the rotor. The outer radial-side wall portion has an inclination angle (first inclination angle) α relative to the radial direction and the inner radial-side wall portion has an inclination angle (second inclination angle) β relative to the radial direction. In this case, in the sixth rotary electrical machine, the inclination angles (the first and second inclination angles) α and β are in a relationship α&gt;β. Accordingly, in the sixth rotary electrical machine, the inclination angle α of the outer radial-side wall portion is larger than the inclination angle β of the inner radial-side wall portion to take in a larger amount of refrigerant (increase the amount of refrigerant). As a result, in the sixth rotary electrical machine, the cooling efficiency is improved. 
     In a seventh rotary electrical machine as an aspect of the technique of the present disclosure, the introduction member has an internal height ( 16   h ) of the protrusion portion that is gradually smaller from the intake portion toward the communication portion. Accordingly, in the seventh rotary electrical machine, the refrigerant moving in the introduction member is increased in pressure. As a result, in the seventh rotary electrical machine, even when the axis of the rotor is long, the refrigerant is guided reliably to the opposite side surface of the through hole. 
     In an eighth rotary electrical machine as an aspect of the technique of the present disclosure, the introduction member has a surface-direction width ( 16   w ) of the protrusion portion that is gradually smaller from the intake portion toward the communication portion along the end surface of the rotor. Accordingly, in the eighth rotary electrical machine, the refrigerant moving in the introduction member is increased in pressure. As a result, in the eighth rotary electrical machine, even when the axis of the rotor is long, the refrigerant is guided reliably to the opposite side surface of the through hole. 
     In a ninth rotary electrical machine as an aspect of the technique of the present disclosure, the introduction members are provided on both end surfaces of the rotor. Further, in the ninth rotary electrical machine, the introduction members  16  are provided such that, on both end surfaces of the rotor, the through hole communicating with one end surface and the through hole communicating with the other end surface are different. Accordingly, in the ninth rotary electrical machine, the refrigerant is taken in from both end surfaces of the rotor and is discharged from the other end surface. As a result, in the ninth rotary electrical machine, cooling can be performed in a balanced manner. 
     In a tenth rotary electrical machine as an aspect of the technique of the present disclosure, the introduction member is provided such that the communication portion communicates with a plurality of openings. In addition, in the tenth rotary electrical machine, the refrigerant is branched so that an equal amount of refrigerant flows into the plurality of openings. Accordingly, in the tenth rotary electrical machine, an equal amount of refrigerant flows into the through holes. Therefore, in the tenth rotary electrical machine, the magnets corresponding to the through holes can be equally cooled. 
     In an eleventh rotary electrical machine as an aspect of the technique of the present disclosure, a plurality of openings is provided on a front side and a rear side with respect to the rotational direction of the rotor. A space from the opening on the front side to the inner wall surface of the protrusion portion (the volume of a first space) has a volume Vf, and a space from the opening on the rear side to the inner wall surface of the protrusion portion (the volume of a second space) has a volume Vr. In this case, in the eleventh rotary electrical machine, the volumes (the volumes of the first and second spaces) Vf and Vr are in a relationship Vf&gt;Vr. Accordingly, in the eleventh rotary electrical machine, while the refrigerant taken in from the intake portion moves toward the through hole, the refrigerant becomes larger in pressure and flow rate with increasing proximity to the rear side in the rotational direction. As a result, in the eleventh rotary electrical machine, an equal amount of refrigerant flows into the through holes positioned on the front side and rear side with respect to the rotational direction of the rotor. 
     In a twelfth rotary electrical machine as an aspect of the technique of the present disclosure, the introduction member is molded integrally with a side plate ( 17 ) provided on the end surface of the rotor. Accordingly, in the twelfth rotary electrical machine, there is no need to prepare a separate introduction member. Therefore, in the twelfth rotary electrical machine, it is possible to suppress the manufacturing cost of the rotor. In addition, in the twelfth rotary electrical machine, the introduction member and the side plate are provided as one component. Accordingly, in the twelfth rotary electrical machine, there is no reduction in the work efficiency during manufacture of the rotor. 
     In a thirteenth rotary electrical machine as an aspect of the technique of the present disclosure, a material for the introduction member is a non-magnetic body or a material including a non-magnetic body. Accordingly, in the thirteenth rotary electrical machine, it is possible to suppress performance degradation due to flux leakage. 
     The “rotor” includes no field winding but has a magnet and a through hole. The “introduction member” has a protrusion portion, an intake portion, and a communication portion. Other components may be arbitrarily provided. The “communication” means that two elements are connected to each other to allow a refrigerant to flow therebetween. The “refrigerant” applies to air, oil, oil mist, or the like. The “side plate” is also called an end plate that is used for assembly of the rotor. The “outer radial side” means the outside with respect to the radial direction of the rotor, and the “inner radial side” means the inside with respect to the radial direction of the rotor. The “non-magnetic metal” refers to all metals unlikely to be attracted to a magnet, such as copper, aluminum, and stainless steel, for example. The “non-magnetic body” has no limitations on its material and composition, provided that magnetic flux is unlikely to flow therein. The non-magnetic body applies to non-metallic materials such as non-magnetic metals and resins. The “rotary electrical machine” may be any device with a shaft (rotation shaft). The rotary electrical machine applies to power generator, electric motor, motor generator, and others, for example. The power generator may be a motor generator acting as a power generator. 
     The electric motor may be a motor generator acting as an electric motor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic cross-sectional view of a first configuration example of a rotary electrical machine; 
         FIG. 2  a cross-sectional view of a first configuration example of a rotor illustrated in  FIG. 1  taken along a line II-II of  FIG. 1 ; 
         FIG. 3  is a side view of the first configuration example of the rotor illustrated in  FIG. 1  as seen from a direction III of  FIG. 1 ; 
         FIG. 4  a side view of the first configuration example of the rotor illustrated in  FIG. 1  as seen from a direction IV of  FIG. 1 ; 
         FIG. 5  is a schematic diagram illustrating a first configuration example of an introduction member; 
         FIG. 6  is a schematic diagram illustrating a second configuration example of the introduction member; 
         FIG. 7  is a schematic diagram illustrating a third configuration example of the introduction member; 
         FIG. 8  is a schematic diagram illustrating a fourth configuration example of the introduction member; 
         FIG. 9  is a schematic diagram illustrating a fifth configuration example of the introduction member; 
         FIG. 10  is a schematic diagram illustrating a sixth configuration example of the introduction member; 
         FIG. 11  is a schematic diagram illustrating a seventh configuration example of the introduction member; 
         FIG. 12  is a schematic diagram illustrating an eighth configuration example of the introduction member; 
         FIG. 13  is a schematic diagram illustrating a ninth configuration example of the introduction member; 
         FIG. 14  is a schematic diagram illustrating a tenth configuration example of the introduction member; 
         FIG. 15  is a schematic diagram illustrating an eleventh configuration example of the introduction member; 
         FIG. 16  is a schematic diagram illustrating a twelfth configuration example of the introduction member; 
         FIG. 17  is a schematic diagram illustrating a thirteenth configuration example of the introduction member; 
         FIG. 18  is a schematic cross-sectional view of a second configuration example of the rotary electrical machine; 
         FIG. 19  is a side view of a second configuration example of a rotor illustrated in  FIG. 18  as seen from a direction XIX of  FIG. 18 ; 
         FIG. 20  is a side view of the second configuration example of the rotor illustrated in  FIG. 18  as seen from a direction XX of  FIG. 18 ; 
         FIG. 21  is a schematic cross-sectional view of a third configuration example of the rotary electrical machine; 
         FIG. 22  is a schematic cross-sectional view of a fourth configuration example of the rotary electrical machine; 
         FIG. 23  is a cross-sectional view of a third configuration example of the rotor; 
         FIG. 24  is a side view of the third configuration example of the rotor; 
         FIG. 25  is a schematic view of a configuration example of an introduction member in which each pole is formed by one magnet; and 
         FIG. 26  is a side view of a fourth configuration example of the rotor. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiments for carrying out the technique of the present disclosure will be described below with reference to the drawings. Unless otherwise specified, the term “to connect” means electrical connection. Each of the drawings illustrates elements necessary for describing the technique of the present disclosure. Therefore, each of the drawings may not illustrate all the actual elements. The upward, downward, rightward, and leftward directions are expressed below based on the illustrations in the drawings. The magnets are hatched in the drawings for differentiation from other elements. Consecutive alphanumeric figures are abbreviated with the word “to”. The form for fixing two elements may be arbitrarily applied. Examples of the form for fixing include fastening with members such as bolts, screws, and pins, joining by welding a molten base material, adhesion with an adhesive, etc. 
     First Embodiment 
     First embodiment will be described with reference to  FIGS. 1 to 17 .  FIG. 1  illustrates an inner rotor-type rotary electrical machine  10 . The rotary electrical machine  10  in the present embodiment has a stator  11 , a rotor  13 , bearings  14 , a shaft  15 , introduction members  16 , a side plate  17 , and the like in a frame  12 . 
     The frame  12  corresponds to a “casing”, “housing”, and the like. The shape and material of the frame  12  can be arbitrarily decided as far as it can accommodate the stator  11 , the rotor  13 , the bearings  14 , the shaft  15 , the introduction members  16 , the side plate  17 , etc. The frame  12  supports and fixes at least the stator  11 . The frame  12  further supports rotatably the shaft  15  via the bearings  14 . The frame  12  in the present embodiment includes non-magnetic frame members  12   a  and  12   b,  etc. The frame members  12   a  and  12   b  may be integrally molded. Alternatively, the frame members  12   a  and  12   b  may be individually formed and then fixed to each other. 
     The stator  11  corresponds to an “armature”, and the like. The stator  11  includes a multi-phase winding  11   a,  a stator core  11   b , etc. The stator core  11   b  can be arbitrarily configured as far as it is a solid soft magnetic body. The stator core  11   b  in the present embodiment is formed by laminating a large number of electromagnetic steel sheets, for example. 
     The multi-phase winding  11   a  is a winding of three or more phases stored and wound in a slot. The multi-phase winding  11   a  corresponds to an armature winding, a stator winding, a stator coil, and the like. The form of the multi-phase winding  11   a  can be arbitrarily decided. Therefore, the cross-sectional shape of the multi-phase winding  11   a  is not limited to a flat square but may be a circle or a triangle. The winding form of the multi-phase winding  11   a  can be arbitrarily decided. Examples of the winding form of the multi-phase winding  11   a  include full-pitch winding, distributed winding, concentrated winding, fractional pitch winding, and the like. The slot is a storage space in the stator core  11   b.    
     As illustrated in  FIGS. 1 and 2 , the rotor  13  in the present embodiment has magnets  13   a , through holes  13   b,  a rotor core  13   c,  storage holes  13   d,  introduction members  16 , a side plate  17 , etc. The rotor  13  is opposed to the stator core  11   b . The rotor  13  is fixed to the shaft  15 . The rotor  13  and the shaft  15  rotate integrally. There is an air gap G between the rotor  13  and the stator  11 . The width of the air gap G (the distance between the rotor  13  and the stator  11 ) can be arbitrarily decided in a range where magnetic flux flows between the rotor  13  and the stator  11  (an arbitrary value can be set within the range of numerical values of distance satisfying this condition). 
     The rotor core  13   c  can be arbitrarily configured as far as it is a solid soft magnetic body. The rotor core  13   c  in the present embodiment is formed by laminating a large number of electromagnetic steel sheets, for example. The through holes  13   b  and the storage holes  13   d  are aligned in the rotor core  13   c  in parallel with the axial direction. The through holes  13   b  and the storage holes  13   d  in the present embodiment communicate with each other. 
     The one or more magnets  13   a  are bar-like magnets that extend axially and are stored in the storage holes  13   d.  As illustrated in  FIGS. 1 and 2 , the magnets  13   a  in the present embodiment are arranged closer to the outer radial side than to the through holes  13   b.  An arbitrary number of magnets  13   a  can be provided according to the number of necessary poles. There are no limitations on the kind of the magnets  13   a.  As illustrated in  FIG. 2 , in the present embodiment, two each magnets  13   a  are provided for each pole. Examples of the kind of the magnets  13   a  include neodymium magnets and others. 
     The one or more through holes  13   b  are bar-like holes that extend axially to allow a refrigerant to flow and cool the magnets  13   a.  The through holes  13   b  in the present embodiment have a barrier function to prevent magnetic leakage of the magnets  13   a.  As illustrated in  FIG. 2 , the through holes  13   b  in the present embodiment are positioned closer to the inner radial side than to the storage holes  13   d.  Two each of the through holes  13   b  adjacent in the circumferential direction of the rotor  13  are deemed as one set, and eight sets are provided in the circumferential direction. 
     The introduction members  16  introduce a refrigerant to cool the magnets  13   a.  As illustrated in  FIGS. 1 and 3 , in the present embodiment, the introduction members  16  are provided on one end surface of the rotor  13  but are not provided on the other end surface of the rotor  13  as seen in the axial direction. An arbitrary number of the introduction members  16  may be provided according to the number of the magnets  13   a,  the number of the through holes  13   b,  etc. As illustrated in  FIG. 3 , in the present embodiment, eight introduction members  16  are provided according to the number of poles of the magnets  13   a.  A specific configuration example of the introduction members  16  will be described later. 
     The side plate  17  is a member that is also called “end plate” and fixes the rotor core  13   c  with the magnets  13   a  stored in the storage holes  13   d  to the shaft  15 . As illustrated in  FIGS. 3 and 4 , in the present embodiment, the side plate  17  has through holes  17   b  that communicate with the through holes  13   b,  and the like. The side plate  17  may include through holes (not illustrated) that communicate with the storage holes  13   d.  A rotational direction D 1  of the rotor  13  illustrated in  FIG. 3  and a rotational direction D 2  of the rotor  13  illustrated in  FIG. 4  are the same. 
     The introduction members  16  and the side plate  17  are formed from a non-magnetic body to suppress performance degradation due to flux leakage. There are no limitations on the substances and constitution of the non-magnetic body under the condition that magnetic flux is unlikely to flow in the non-magnetic body. Examples of the non-magnetic body include non-magnetic metals such as copper, aluminum, and stainless steel, and non-metallic materials such as resin. The introduction members  16  and the side plate  17  in the present embodiment are formed from a non-magnetic metal or a non-metallic material. The material for the introduction members  16  and the side plate  17  is desirably higher in thermal conductivity than the rotor core  13   c  to enhance heat dissipation. The introduction members  16  and the side plate  17  in the present embodiment are integrally molded. 
     A configuration example of the introduction members  16  will be described with reference to  FIGS. 5 to 17 . As illustrated in  FIGS. 5 to 17 , each of the introduction members  16  includes an intake portion  16   a,  a protrusion portion  16   b,  and a communication portion  16   c.  The shape of the introduction member  16  can be arbitrarily decided as far as it can guide a refrigerant  18   a  from the intake portion  16   a  through the protrusion portion  16   b  to the communication portion  16   c.  The introduction member  16  may have a shape with a continuous cross section such as scoop, pipe, tunnel, arcade, and arch, for example. The same elements illustrated in  FIGS. 5 to 17  are given identical reference signs. 
     The intake portion  16   a  is provided at one end of the protrusion portion  16   b  and is opened toward the rotational direction D 1  of the rotor  13  to take in a refrigerant. The refrigerant  18   a  is a fluid. The refrigerant may be air, oil, oil mist, or the like, for example. The intake portion  16   a  is provided along the radial direction of the rotor  13  unless otherwise specified. In the present embodiment, the air is used as the refrigerant  18   a.  The protrusion portion  16   b  protrudes axially from the end surface of the rotor  13 . The communication portion  16   c  is provided at the other end of the protrusion portion  16   b.  The communication portion  16   c  communicates partly or entirely with an opening  13   b   1  of the through hole  13   b  illustrated in  FIGS. 15 to 17 . When the communication portion  16   c  and the opening  13   b   1  partly communicate with each other, the portion of the opening  13   b   1  not communicating with the communication portion  16   c  is blocked by the side plate  17 . 
     First, a configuration example of the protrusion portion  16   b  of the introduction member  16 , including its planar shape, arrangement, and number, will be described with reference to  FIGS. 5 to 10 . 
     As illustrated in  FIG. 5 , in the introduction member  16  of a first configuration example in the present embodiment, the intake portion  16   a,  the protrusion portion  16   b,  and the communication portion  16   c  are provided along the circumferential direction of the rotor  13 . The refrigerant  18   a  taken in by the intake portion  16   a  is sent directly to both the through holes  13   b  adjacent to each other in the circumferential direction of the rotor  13  through the protrusion portion  16   b  and the communication portion  16   c.  The introduction member  16  may be configured as indicated with two-dot chain lines, including a ninth configuration example described later (see  FIG. 13 ). 
     As illustrated in  FIG. 6 , the introduction member  16  of a second configuration example in the present embodiment has the intake portion  16   a  and the communication portion  16   c  shifted in the radial direction of the rotor  13 . Specifically, the introduction member  16  has the intake portion  16   a  further radially outward than the communication portion  16   c.  The protrusion portion  16   b  connecting the intake portion  16   a  and the communication portion  16   c  may have a linear shape as indicated with solid lines. Alternatively, the protrusion portion  16   b  may have an arc shape or a curve shape as indicated with two-dot chain lines. As in the present configuration example, the intake portion  16   a  provided on the outer radial side has a larger amount of rotational movement than that of the introduction member  16  in the first configuration example. Accordingly, in the present configuration example, a larger amount of refrigerant is taken in. 
     As illustrated in  FIG. 7 , the introduction member  16  of a third configuration example in the present embodiment is shaped such that a surface-direction width  16   w  of the protrusion portion  16   b  along the end surface of the rotor  13  is gradually smaller from the intake portion  16   a  toward the communication portion  16   c.  That is, the introduction member  16  has the wide intake portion  16   a  to take in the refrigerant  18   a.  Accordingly, in the present configuration example, the refrigerant  18   a  is increased in pressure and is larger in flow rate while moving in the protrusion portion  16   b.    
     As illustrated in  FIG. 8 , in the introduction member  16  of a fourth configuration example in the present embodiment, an outer radial-side portion of the intake portion  16   a  protrudes toward the rotational direction D 1  of the rotor  13  more than an inner radial-side portion of the intake portion  16   a.  That is, the introduction member  16  is larger in circumference and increased in the amount of rotational movement with increasing proximity to the outer radial side. Accordingly, in the present configuration example, the intake amount of the refrigerant  18   a  can be increased. 
     As illustrated in  FIG. 9 , the number of the introduction members  16  of a fifth configuration example in the present embodiment corresponds to the number of the through holes  13   b.  As illustrated in  FIG. 2 , in the present embodiment, two each through holes  13   b  are provided for each pole of the magnet  13   a.  Accordingly, as illustrated in  FIG. 9 , two each introduction members  16  in the present configuration example are provided in the same manner. The two introduction members  16  are arranged on the outer radial side and the inner radial side such that they communicate with the corresponding through holes  13   b.  Referring to  FIG. 9 , the introduction member  16  illustrated on the upper side corresponds to the introduction member  16  on the outer radial side and the introduction member  16  illustrated on the lower side corresponds to the introduction member  16  on the inner radial side. To cool equally the two magnets  13   a  by equalizing the flow rates of the refrigerant  18   a  into the two through holes  13   b,  the two introduction members  16  desirably have the intake portions  16   a  equal in opening areas. 
     As illustrated in  FIG. 10 , the introduction member  16  of a sixth configuration example in the present embodiment is a modification of the fifth configuration example. The fifth configuration example has the two introduction members  16 . In contrast to this, the present configuration example has one introduction member  16  with a division wall  16   d.  The division wall  16   d  is provided from the intake portion  16   a  to the communication portion  16   c.  An outer radial-side first intake portion  16   a   1  divided by the division wall  16   d  corresponds to the outer radial-side intake portion  16   a  illustrated in  FIG. 9 . An inner radial-side second intake portion  16   a   2  corresponds to the inner radial-side intake portion  16   a  illustrated in  FIG. 9 . As in the case with the fifth configuration example, to cool equally the two magnets  13   a,  the first intake portion  16   a   1  and the second intake portion  16   a   2  are desirably equal in opening area. 
     Next, a configuration example of the front shape of the intake portion  16   a  of the introduction member  16  will be described with reference to  FIGS. 11 to 14 . 
     As illustrated in  FIG. 11 , the introduction member  16  of a seventh configuration example in the present embodiment has an intake portion  16   a  with a semi-circular front surface. Specifically, the introduction member  16  has the semi-circular intake portion  16   a  including an outer radial-side wall portion  16   ae  and an inner radial-side wall portion  16   ai . The outer radial-side wall portion  16   ae  has an inclination angle (first inclination angle) α relative to the radial direction, and the inner radial-side wall portion  16   ai  has an inclination angle (second inclination angle) β relative to the radial direction. In this case, the first and second inclination angles α and β are in a relationship α=β. That is, the introduction member  16  has the equal inclination angles α and β with respect to the outer radial-side wall and the inner radial-side wall. Accordingly, in the present configuration example, the refrigerant  18   a  is equally taken in on the outer radial side and the inner radial side of the introduction member  16 . 
     As illustrated in  FIG. 12 , the introduction member  16  of an eighth configuration example in the present embodiment has the intake portion  16   a  including an outer radial-side wall portion  16   ae  and an inner radial-side wall portion  16   ai . The outer radial-side wall portion  16   ae  has an inclination angle (first inclination angle) α relative to the radial direction, and the inner radial-side wall portion  16   ai  has an inclination angle (second inclination angle) β relative to the radial direction. In this case, the first and second inclination angles α and β are in a relationship α&gt;β. That is, in the introduction member  16 , the inclination angle α of the outer radial-side wall portion  16   ae  is larger than the inclination angle β of the inner radial-side wall portion  16   ai . Accordingly, the introduction member  16  becomes larger in circumference and increases in the amount of rotational movement with increasing proximity to the outer radial side. Therefore, in the present configuration example, the intake amount of the refrigerant  18   a  can be increased. 
     As illustrated in  FIG. 13 , the introduction member  16  of a ninth configuration example in the present embodiment has the intake portion  16   a  of an inverse J shape from the outer radial-side end to the peak portion. As illustrated with the two-dot chain lines in  FIGS. 13 and 5 , the introduction member  16  is configured such that the axial protrusion is gradually closed from the intake portion  16   a  to the middle of the protrusion portion  16   b.  Accordingly, in the present configuration example, the refrigerant  18   a  is guided toward the communication portion  16   c.    
     As illustrated in  FIG. 14 , the introduction member  16  of a tenth configuration example in the present embodiment has the intake portion  16   a  with a square front surface together with the side plate  17 . In the present configuration example, as in the case with the seventh configuration example illustrated in  FIG. 11 , the inclination angles α and β of the outer radial-side and inner radial-side walls are equal. Accordingly, in the present configuration example, the refrigerant  18   a  is equally taken in on the outer radial side and inner radial side of the introduction member  16 . The introduction member  16  of the present configuration example may be configured such that the inclination angle α of the outer radial-side wall portion  16   ae  and the inclination angle β of the inner radial-side wall portion  16   ai  are in the relationship of α&gt;β (not illustrated) as in the eighth configuration example illustrated in  FIG. 12 . In addition, the introduction member  16  of the present configuration example may be configured to have an inverse L shape from the outer radial-side end to the peak portion as in the ninth configuration example illustrated in  FIG. 13 . Further, as illustrated with two-dot chain lines in  FIG. 14 , the introduction member  16  in the present configuration example may be configured such that the intake portion  16   a  is partly curved (at the corners of the square shape). 
     Further, a configuration example of a cross-sectional shape of the protrusion portion  16   b  of the introduction member  16  will be described with reference to  FIGS. 15 to 17 . Each of  FIGS. 15 to 17  illustrates the flow of the refrigerant  18   a  with arrow D 3  (hereinafter, called “introduction direction D 3 ”). As indicated by the introduction direction D 3  in each of the drawings, the refrigerant  18   a  is taken into the introduction member  16  via the intake portion  16   a . After that, the refrigerant  18   a  flows along the protrusion portion  16   b  of the introduction member  16 , and then flows into the through hole  13   b  of the rotor  13  through the communication portion  16   c  and the through hole  17   b.  An internal height  16   h  illustrated in  FIGS. 15 to 17  refers to the height of the space in which the refrigerant  18   a  flows in the introduction member  16 . 
     As illustrated in  FIG. 15 , the introduction member  16  of an eleventh configuration example in the present embodiment includes the protrusion portion  16   b  having a first protrusion portion  16   b   1  and a second protrusion portion  16   b   2 . The first protrusion portion  16   b   1  is a portion in which the internal height  16   h  from the intake portion  16   a  to the side plate  17  does not change. The second protrusion portion  16   b   2  is a region that is arc-shaped in cross section and includes the communication portion  16   c  on the rear side (the right side of  FIG. 15 ) with respect to the rotational direction D 1  of the rotor  13 . Accordingly, the internal height  16   h  is low in the second protrusion portion  16   b   2 . 
     As illustrated in  FIG. 16 , the introduction member  16  of a twelfth configuration example in the present embodiment has the protrusion portion  16   b  in which the internal height  16   h  becomes gradually lower from the intake portion  16   a  to the communication portion  16   c . Accordingly, in the present configuration example, the refrigerant  18   a  is enhanced in pressure and is increased in flow rate while moving in the introduction member  16 . 
     The magnet  13   a  is equally cooled in the two through holes  13   b.  Accordingly, the refrigerant  18   a  is desirably branched such that the flow rates into the openings  13   b   1  become equal. The present configuration example is configured such that a volume Vf of a first space hatched in  FIG. 16  and a volume Vr of a second space hatched in  FIG. 6  are in a relationship Vf&gt;Vr. The volume Vf of the first space is the volume of a space from the front-side opening  13   b   1  with respect to the rotational direction D 1  of the rotor  13  to the inner wall surface of the protrusion portion  16   b  (the left part hatched in  FIG. 16 ). The volume Vr of the second space is the volume of a space from the rear-side opening  13   b   1  with respect to the rotational direction D 1  of the rotor  13  to the inner wall surface of the protrusion portion  16   b  (the right part hatched in  FIG. 16 ). 
     As illustrated in  FIG. 17 , the introduction member  16  of a thirteenth configuration example in the present embodiment is a modification of the eleventh configuration example. The present configuration example is different from the eleventh configuration example in including the communication portion  16   c  that equalizes the flow rates of the refrigerant  18   a  into the two through holes  13   b.  In the twelfth configuration example, the volume Vf of the first space and the volume Vr of the second space are in the relationship Vf&gt;Vr. In contrast to this, the communication portion  16   c  of the present configuration example has a first communication portion  16   c   1  and a second communication portion  16   c   2  different in opening area. The first communication portion  16   c   1  has an opening area (first area) Sf, and the second communication portion  16   c   2  has an opening area (second area) Sr. In this case, the opening areas of the communication portions are preferably configured such that the first area Sf and the second area Sr are in the relationship Sf&gt;Sr. 
     The introduction member  16  in the present embodiment can be formed by combining the configurations of the examples described above. Specifically, the first to sixth configuration examples relating to the planar shape of the protrusion portion  16   b,  the seventh to tenth configuration examples relating to the planar shape of the intake portion  16   a,  and the eleventh to thirteenth configuration examples relating to the cross-sectional shape of the protrusion portion  16   b  can be combined in any way. Accordingly, there are a total of 72 (=6×4×3) combinations of the introduction member  16  in the present embodiment. For example, for the introduction member  16 , there are combinations of {the first configuration example, the seventh configuration example, and the eleventh configuration example}, combinations of {the second configuration example, the eighth configuration example, and the twelfth configuration example}, combinations of {the third configuration example, the ninth configuration example, and the thirteenth configuration example}, combinations of {the sixth configuration example, the tenth configuration example, and the thirteenth configuration example}, etc. For the introduction member  16  in the present embodiment, the configurations of the examples can be combined depending on the specifications and rating of the rotary electrical machine  10 , the forms of the magnets  13   a  and the through holes  13   b  (for example, shape, size, and number), and others, for example. 
     The foregoing rotary electrical machine  10  in the present embodiment produces the advantageous effects described below. 
     (1) The rotary electrical machine  10  illustrated in  FIG. 1  has the rotor  13 , the stator  11 , etc. The rotor  13  has the magnets  13   a,  the through holes  13   b,  the rotor core  13   c,  the storage holes  13   d,  the introduction members  16 , the side plate  17 , etc. The introduction members  16  communicate partly or entirely with the openings  13   b   1  of the one or more through holes  13   b  and introduce the refrigerant  18   a.  Each of the introduction members  16  includes the intake portion  16   a,  the protrusion portion  16   b,  and the communication portion  16   c.  As illustrated in  FIGS. 5 to 10 , the intake portion  16   a  is provided at the one end of the protrusion portion  16   b  and is opened toward the rotational direction D 1  of the rotor  13  to take in the refrigerant  18   a.  The protrusion portion  16   b  protrudes axially from the end surface of the rotor  13 . As illustrated in  FIGS. 15 to 17 , the communication portion  16   c  is provided at the other end of the protrusion portion  16   b.  The communication portion  16   c  communicates with the two openings  13   b   1  adjacent to each other in the circumferential direction. In this way, in the rotary electrical machine  10 , the introduction members  16  protrude axially from the end surface of the rotor  13  and are opened toward the rotational direction D 1  of the rotor  13 . Accordingly, in the rotary electrical machine  10 , the refrigerant  18   a  can be actively introduced without influence of the air-curtain effect. As a result, in the rotary electrical machine  10 , it is possible to cool efficiently the magnets  13   a  that might suffer performance degradation due to temperature rise. Accordingly, in the rotary electrical machine  10 , it is possible to suppress decrease in the characteristics and performance of the magnets  13   a.  In addition, in the rotary electrical machine  10 , it is possible to reduce the amount of dysprosium used to avoid thermal demagnetization of the magnets  13   a  (the usage of rare earth element). Accordingly, in the rotary electrical machine  10 , it is possible to suppress the manufacturing cost of the rotor  13 . In the rotary electrical machine  10 , each of the two openings  13   b   1  communicates with the corresponding storage hole  13   d  in which the magnet  13   a  is stored. Accordingly, in the rotary electrical machine  10 , both magnets  13   a  can be efficiently cooled. 
     (2) As illustrated in  FIGS. 1 and 2 , in the rotary electrical machine  10 , the magnets  13   a  are arranged closer to the outer radial side than to the through holes  13   b.  Accordingly, the refrigerant  18   a  passing through the through holes  13   b  moves in such a manner as to be attracted to the outer radial side on which the magnets  13   a  are arranged under centrifugal action. Accordingly, in the rotary electrical machine  10 , the magnets  13   a  can be efficiently cooled. 
     (3) As illustrated in  FIGS. 2 to 10 , in the rotary electrical machine  10 , the through holes  13   b  communicate with the storage holes  13   d  storing the magnets  13   a  and have the barrier function to prevent magnetic leakage of the magnets  13   a.  Accordingly, the through holes  13   b  act as magnetic leakage preventive barriers to prevent magnetic leakage of the magnets  13   a . Accordingly, in the rotary electrical machine  10 , the refrigerant  18   a  can cool not only the wall surfaces of the through holes  13   b  but also the side surfaces of the magnets  13   a.    
     (4) As illustrated in  FIGS. 5 to 17 , in the rotary electrical machine  10 , the introduction members  16  are scoop-shaped. Accordingly, in the rotary electrical machine  10 , the refrigerant  18   a  subjected to rotational force can be passed into the through holes  13   b  without waste. As a result, in the rotary electrical machine  10 , the magnets  13   a  can be efficiently cooled. 
     (5) As illustrated in  FIG. 6 , in the rotary electrical machine  10 , the intake portion  16   a  is positioned closer to the outer radial side than to the communication portion  16   c.  Accordingly, in the rotary electrical machine  10 , the amount of rotational movement becomes larger with increasing proximity to the outer radial side to take in a larger amount of refrigerant  18   a  (increase the amount of refrigerant). As a result, in the rotary electrical machine  10 , the cooling efficiency is improved. 
     (6) As illustrated in  FIG. 12 , in the rotary electrical machine  10 , the intake portion  16   a  includes the outer radial-side wall portion  16   ae  and the inner radial-side wall portion  16   ai  that extend axially from the end surface of the rotor  13 . The outer radial-side wall portion  16   ae  has the inclination angle (first inclination angle) α relative to the radial direction and the inner radial-side wall portion  16   ai  has the inclination angle (second inclination angle) β relative to the radial direction. In this case, in the rotary electrical machine  10 , the first and second inclination angles α and β are in the relationship α&gt;β. Accordingly, in the rotary electrical machine  10 , the inclination angle α of the outer radial-side wall portion  16   ae  is larger than the inclination angle β of the inner radial-side wall portion  16   ai  to take in a larger amount of the refrigerant  18   a  (increase the amount of the refrigerant). As a result, in the rotary electrical machine  10 , the cooling efficiency is improved. 
     (7) As illustrated in  FIG. 16 , in the rotary electrical machine  10 , the introduction member  16  has the internal height ( 16   h ) of the protrusion portion  16   b  that is gradually smaller from the intake portion  16   a  toward the communication portion  16   c.  Accordingly, in the rotary electrical machine  10 , the refrigerant  18   a  is gradually increased in pressure while moving in the introduction member  16 . As a result, in the rotary electrical machine  10 , even when the axis of the rotor  13  illustrated in  FIG. 1  is long, the refrigerant  18   a  is guided reliably to the opposite side surface (the right side surface in  FIG. 1 ) of the through hole  13   b.    
     (8) As illustrated in  FIG. 7 , in the rotary electrical machine  10 , the surface-direction width ( 16   w ) of the protrusion portion  16   b  is gradually smaller from the intake portion  16   a  toward the communication portion  16   c  along the end surface of the rotor  13 . Accordingly, in the rotary electrical machine  10 , the refrigerant  18   a  is gradually increased in pressure while moving in the introduction member  16 . As a result, in the rotary electrical machine  10 , even when the axis of the rotor  13  illustrated in  FIG. 1  is long, the refrigerant  18   a  is guided reliably to the opposite side surface (the right side surface in  FIG. 1 ) of the through hole  13   b.    
     (10) As illustrated in  FIGS. 15 to 17 , in the introduction member  16  of the rotary electrical machine  10 , the introduction member  16  is provided such that the communication portion  16   c  communicates with the plurality of openings  13   b   1 . The refrigerant  18   a  is branched such that an equal amount of refrigerant  18   a  flows into the plurality of openings  13   b   1 . Accordingly, in the rotary electrical machine  10 , an equal amount of refrigerant  18   a  flows into the through holes  13   b.  Accordingly, in the rotary electrical machine  10 , the magnets  13   a  corresponding to the through holes  13   b  can be equally cooled. 
     (11) As illustrated in  FIGS. 15 to 17 , in the rotary electrical machine  10 , the plurality of openings  13   b   1  is provided on the front side and the rear side with respect to the rotational direction D 1  of the rotor  13 . As illustrated in  FIG. 16 , the first space from the front-side opening  13   b   1  to the inner wall surface of the protrusion portion  16   b  has the volume Vf, and the second space from the rear-side opening  13   b   1  to the inner wall surface of the protrusion portion  16   b  has the volume Vr. In this case, in the rotary electrical machine  10 , the first and second spaces Vf and Vr are in the relationship Vf&gt;Vr. Accordingly, in the rotary electrical machine  10 , while the refrigerant  18   a  taken in from the intake portion  16   a  moves toward the through hole  13   b,  the refrigerant  18   a  is increased in pressure and flow rate with increasing proximity to the rear side in the rotational direction D 1 . As a result, in the rotary electrical machine  10 , an equal amount of refrigerant  18   a  flows into the through holes  13   b  positioned on the front side and rear side with respect to the rotational direction D 1  of the rotor  13 . 
     (12) As illustrated in  FIGS. 1 and 15 to 17 , in the rotary electrical machine  10 , the introduction member  16  is molded integrally with the side plate  17  provided on the end surface of the rotor  13 . Accordingly, in the rotary electrical machine  10 , there is no need to prepare a separate introduction member  16 . Accordingly, in the rotary electrical machine  10 , it is possible to suppress the manufacturing cost of the rotor  13 . In addition, in the rotary electrical machine  10 , the introduction member  16  and the side plate  17  are provided as one component. Accordingly, in the rotary electrical machine  10 , there is no reduction in the work efficiency during manufacture of the rotor  13 . 
     (13) As illustrated in  FIG. 1 , in the rotary electrical machine  10 , the material for the introduction member  16  is a non-magnetic body or a material including a non-magnetic body. Accordingly, in the rotary electrical machine  10 , it is possible to suppress performance degradation due to flux leakage. 
     Second Embodiment 
     A second embodiment will be described with reference to  FIGS. 18 to 20 . For simplicity of illustration and description, unless otherwise specified, the same components as those of the first embodiment will be given the same reference signs and description thereof will be omitted. Accordingly, differences from the first embodiment will be mainly described. 
       FIG. 18  illustrates an inner rotor-type rotary electrical machine  10 . The rotary electrical machine  10  in the present embodiment has a stator  11 , a rotor  13 , a bearing  14 , a shaft  15 , introduction members  16 , a side plate  17 , and others in a frame  12 , as in the first embodiment. In the first embodiment, all the introduction members  16  are provided at one end surface of the rotor  13  as seen from the axial direction as illustrated in  FIG. 1 . The rotary electrical machine  10  in the present embodiment is different from the rotary electrical machine  10  in the first embodiment in the position of the introduction members  16 . 
     In the rotary electrical machine  10  in the present embodiment, as illustrated in  FIG. 18 , the introduction members  16  are provided on both end surfaces of the rotor  13 . Further, in the rotary electrical machine  10 , as illustrated in  FIGS. 19 and 20 , the introduction members  16  are provided such that, on both end surfaces of the rotor  13 , the through hole  13   b  communicating on one end surface and the through hole  13   b  communicating on the other end surface are different. The introduction members  16  in the present embodiment are configured in the same manner as those in the first embodiment. 
     In the rotary electrical machine  10  in the present embodiment, the same advantageous effects as those in the first embodiment can be obtained and the following advantageous effects can also be obtained. 
     (9) As illustrated in  FIGS. 18 to 20 , in the rotary electrical machine  10 , the introduction members  16  are provided on both end surfaces of the rotor  13 . Further, in the rotary electrical machine  10 , the introduction members  16  are provided such that, on both end surfaces of the rotor  13 , the through hole  13   b  communicating with one end surface and the through hole  13   b  communicating with the other end surface are different. Accordingly, in the rotary electrical machine  10 , the refrigerant  18   a  is taken in from both end surfaces of the rotor  13  and is discharged from the other end surface. As a result, in the rotary electrical machine  10 , cooling can be performed in a balanced manner. 
     Third Embodiment 
     A third embodiment will be described with reference to  FIGS. 21 and 22 . For simplicity of illustration and description, unless otherwise specified, the same components as those of the first to second embodiments will be given the same reference signs and description thereof will be omitted. Accordingly, differences from the first and second embodiments will be mainly described. 
       FIGS. 21 and 22  illustrate an inner rotor-type rotary electrical machine  10 . The rotary electrical machine  10  in the present embodiment has a stator  11 , a rotor  13 , a bearing  14 , a shaft  15 , introduction members  16 , a side plate  17 , and others in a frame  12 , as in the first embodiment. In the first and second embodiments, the air is used as the refrigerant  18   a.  The rotary electrical machine  10  in the present embodiment is different from the rotary electrical machines  10  in the first and second embodiments in that oil is used as the refrigerant  18   b.  In the present embodiment, the capacity for the refrigerant  18   b  is desirably set such that the introduction members  16  on the lower sides of  FIGS. 21 and 22  are under the liquid level. 
     The rotary electrical machine  10  illustrated in  FIG. 21  is similar to the rotary electrical machine  10  illustrated in  FIG. 1  (the rotary electrical machine  10  in the first embodiment) except for the refrigerant  18   b.  Accordingly, in the rotary electrical machine  10  in the present embodiment, the same advantageous effects as those of the first embodiment can be obtained. In addition, the rotary electrical machine  10  illustrated in  FIG. 22  is similar to the rotary electrical machine  10  illustrated in  FIG. 18  (the rotary electrical machine  10  in the second embodiment) except for the refrigerant  18   b.  Accordingly, in the rotary electrical machine  10  in the present embodiment, the same advantageous effects as those of the second embodiment can be obtained. 
     Fourth Embodiment 
     A fourth embodiment will be described with reference to  FIGS. 23 and 24 . For simplicity of illustration and description, unless otherwise specified, the same components as those of the first to third embodiments will be given the same reference signs and description thereof will be omitted. Accordingly, differences from the first to third embodiments will be mainly described. 
     The rotor  13  illustrated in  FIG. 23  is a substitute for the rotors  13  illustrated in  FIGS. 1, 18, 21, and 22 . The rotor  13  in the present embodiment has a plurality of partial rotors  131  to  134 . The partial rotors  131  to  134  are configured in the same manner as the rotors  13  illustrated in  FIGS. 1, 18, 21, and 22 . The partial rotors  131  to  134  are different from those in the first to third embodiments in that the axial length is shorter. In the present embodiment, the rotor  13  has the four partial rotors  131  to  134 , but the technique of the present disclosure is not limited to this. The number of the partial rotors included in the rotor  13  can be arbitrarily set to two or more. 
     The partial rotors  131  and  133  are configured as illustrated in  FIG. 2 , for example. The partial rotors  132  and  134  are configured as illustrated in  FIG. 24 , for example. With the partial rotors  131  and  133  configured as illustrated in  FIG. 2  at reference positions, the partial rotors  132  and  134  are positioned with a turn of an angle θ. In the present embodiment, the partial rotors  132  and  134  are shifted at the angle θ circumferentially. Accordingly, as illustrated in  FIG. 23 , the positions of the magnets  13   a  and the through holes  13   b  are shifted circumferentially. In this manner, in the present embodiment, even when the through holes  13   b  are shifted circumferentially, the refrigerant  18   a  or  18   b  passes through the introduction members  16  and flow from one axial end surface to the other axial surface illustrated in  FIG. 23 . Accordingly, in the present embodiment, the same advantageous effects as those of the first to third embodiment can be obtained. 
     In the rotor  13  in the present embodiment, the plurality of partial rotors  131  to  134  can be shifted in any way as far as the refrigerant  18   a  or  18   b  can flow from the one axial end surface to the other axial end surface. For example, in the rotor  13 , the partial rotors  131  and  134  may be arranged at reference positions and the partial rotors  132  and  133  may be arranged at positions with a turn of the angle θ. Alternatively, in the rotor  13 , the partial rotor  131  may be arranged at a reference position, the partial rotor  132  may be arranged at a position with a turn of an angle  2 θ, the partial rotor  133  may be arranged at a position turned with a turn of an angle  3 θ, and the partial rotor  134  may be arranged at a position with a turn of an angle  4 θ. Still alternatively, in the rotor  13 , the angle θ at which the partial rotors  131  to  134  are shifted may not be constant but may be changed. In the rotary electrical machine  10  in the present embodiment, even when each of the partial rotors  131  to  134  is arranged in any way, the same advantageous effects as those of the first to third embodiments can be obtained as far as the foregoing condition (that the refrigerant  18   a  or  18   b  can flow) is satisfied. 
     Other Embodiments 
     The first to fourth embodiments as modes for carrying out the technique of the present disclosure have been described so far, but the technique of the present disclosure is not limited to them. The technique of the present disclosure can be carried out in various manners. For example, the following modes may be implemented. 
     In the first to fourth embodiments described above, as illustrated in  FIGS. 2 and 24 , the number of poles of the rotor  13  is set to eight and two each magnets  13   a  are provided for each pole. Instead of this mode, in a modification example, the number of poles of the rotor  13  may be set to any value other than eight. In addition, as illustrated in  FIG. 25 , one each magnet  13   a  may be provided for each pole. In the rotor  13  illustrated in  FIG. 25 , the magnet  13   a  is stored in the storage hole  13   d.  The through hole  13   b  is provided from both sides of the storage hole  13   d  in the circumferential direction of the rotor  13 . The introduction member  16  indicated by two-dot chain lines is provided to introduce the refrigerant  18   a  or  18   b  into the two through holes  13   b.  Three or more magnets  13   a  may be provided for each pole (not illustrated). One magnet  13   a  may be formed from a plurality of partial magnets. In this way, the present modification example and the first to fourth embodiments are different only in the number of the magnets  13   a  provided for each pole. Accordingly, in the present modification example, the same advantageous effects as those of the first to fourth embodiments can be obtained. 
     In the first to fourth embodiments, the through holes  13   b  and the storage holes  13   d  are formed in the shapes as illustrated in  FIGS. 2 to 4, 19, 20, and 24 . Instead of this mode, in a modification example, the through holes  13   b  and the storage holes  13   d  may be formed in the shapes as illustrated in  FIG. 26 . That is, the through holes  13   b  can be implemented in any shape on the condition that the refrigerant  18   a  or  18   b  can flow. The storage holes  13   d  can be implemented in any shape on the condition that the magnets  13   a  can be stored. In this way, the present modification example and the first to fourth embodiments are different only in the shapes of the through holes  13   b  and the storage holes  13   d.  Accordingly, in the present modification example, the same advantageous effects as those of the first to fourth embodiments can be obtained. 
     In the first to fourth embodiments, as illustrated in  FIGS. 1, 18, 21, and 22 , the introduction members  16  and the side plate  17  are integrally molded. Instead of this mode, in a modification example, the separately molded introduction members  16  and side plate  17  may be fixed together. In this configuration, as illustrated in  FIGS. 15 and 16 , the communication portion  16   c  and the through hole  17   b  are desirably formed in the same shape. In addition, referring to  FIG. 17 , the opening area of a second communication portion  16   c   2  is made smaller than the opening area of a first communication portion  16   c   1 . Instead of this mode, in a modification example, the opening area of the through hole  17   b  corresponding to the second communication portion  16   c   2  may be made smaller than the opening area of the through hole  17   b  corresponding to the first communication portion  16   c   1 . In this way, the present modification example and the first to fourth embodiments are different only in whether the introduction members  16  and the side plate  17  are formed integrally or separately. Accordingly, in the present modification example, the same advantageous effects as those of the first to fourth embodiments can be obtained. 
     In the first to fourth embodiments, the technique in the present disclosure is applied to the inner rotor-type rotary electrical machines  10 . Instead of this mode, in a modification example, the technique in the present disclosure may be applied to outer rotor-type rotary electrical machines. In this way, the present modification example and the first to fourth embodiments are different only in the arrangement of the stator  11  and the rotor  13 . Accordingly, in the present modification example, the same advantageous effects as those of the first to fourth embodiments can be obtained. 
     REFERENCE SIGNS LIST 
       1  . . . Rotary electrical machine 
       11  . . . Stator 
       13  . . . Rotor 
       13   a  . . . Magnet 
       13   b  . . . Through hole 
       13   c  . . . Rotor core 
       13   d  . . . Storage hole 
       16  . . . Introduction member 
       16   a  . . . Intake portion 
       16   b  . . . Protrusion portion 
       16   c  . . . Communication portion 
       17  . . . Side plate 
       18   a,    18   b  . . . Refrigerant