Abstract:
A actuator and a pump using the actuator are provided. The actuator is used to drive a pump body. The actuator includes a base, a transmission assembly and a motor received in the base. The motor includes a stator, a rotor, and a driving shaft. The driving shaft is connected to the transmission assembly. The base includes a mounting bracket. The mounting bracket is partly embedded in the motor. The actuator has good integrality and a compact structure.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This non-provisional patent application claims priority under 35 U.S.C. §119(a) from Patent Application No. 201510818236.0 filed in The People&#39;s Republic of China on Nov. 23, 2015. 
       FIELD OF THE INVENTION 
       [0002]    This invention relates to the field of pumps, and in particular, to a actuator and a pump using the actuator. 
       BACKGROUND OF THE INVENTION 
       [0003]    As a kind of driving device, motors are widely used in various applications. A common application of the motors is using the motors to drive pumps to achieve the function of pumping water or evacuation. In a current common mechanism which uses a motor to drive a pump to perforin the work of pumping water or evacuation, a conventional complete motor is generally assembled to the pump, with an output shaft of the motor being connected to the pump to drive the pump to rotate. Because the motor is an independently-operable complete motor which includes components of two bearings, end covers, etc, the whole driving device has a large size and weight. 
       SUMMARY OF THE INVENTION 
       [0004]    Accordingly, there is a desire for a compact actuator and a pump using the actuator. 
         [0005]    In one aspect, a actuator used to drive a pump body is provided. The actuator includes a base comprising a mounting bracket, a transmission assembly and a motor received in the base. The motor includes a stator, a rotor, and a driving shaft fixed to the rotor. The driving shaft is connected to the transmission assembly. The base includes a mounting bracket. The mounting bracket is partly embedded in the motor. 
         [0006]    Preferably, the mounting bracket comprises a connecting board positioned between the motor and the transmission assembly, and a sleeve extending from a side of the connecting board along an axial direction of the driving shaft, the stator is supported on sleeve, the driving shaft rotatably received in the sleeve, and the rotor is rotatably mounted around the stator. 
         [0007]    Preferably, the sleeve is integrally formed with the connecting board. 
         [0008]    Preferably, the base further comprises a rear cover, the rear cover is disposed at one side of the mounting bracket away from the stator, the actuator further comprises two supporting bearings for rotatably supporting the driving shaft, and the two supporting bearings are fixed to the rear cover and the mounting bracket close to the connecting board, respectively. 
         [0009]    Preferably, the sleeve forms at least one guiding member to enable the stator attached thereto with a predetermined orientation. 
         [0010]    Preferably, the motor is a brushless direct current motor, the motor further comprises a controller, the controller is disposed between the mounting bracket and the stator. 
         [0011]    Preferably, the controller is fixed onto the connecting board. 
         [0012]    Preferably, the base further comprises a front cover accommodating the motor, the connecting board and the front cover are connected through a snap-fit connection. 
         [0013]    Preferably, the mounting bracket defines a receiving chamber accommodating the transmission assembly. 
         [0014]    Preferably, the transmission assembly comprises a bearing seat, a transmission bearing, and an eccentric bushing, the transmission bearing is mounted in the bearing seat, the bearing seat is received in the receiving chamber, one side of the bearing seat is connected to the pump body, the eccentric bushing is fixedly sleeved on the driving shaft and rotatably mounted in the transmission bearing. 
         [0015]    Preferably, the eccentric bushing is cylindrical and defines a through hole, an axis of the eccentric bushing is offset from an axis of the through hole, the driving shaft passes through the through hole of the eccentric bushing such that the eccentric bushing rotates along with the driving shaft. 
         [0016]    Preferably, the stator is an armature, and the rotor is an excitation assembly with a plurality of permanent magnets. 
         [0017]    In another aspect, a pump is provided which includes a pump body, an actuator for driving the pump body, the actuator includes a base, a transmission assembly received in the base; and a motor, the motor is an outer rotor motor and includes a stator directly fixed to the base, a rotor rotatably mounted around the stator, and a driving shaft connected to the transmission assembly and fixed to the rotor. 
         [0018]    Preferably, the base comprises a mounting bracket and a front cover detachably assembled to one side of the mounting bracket, the stator is directly fixed to the mounting bracket, and the front cover receives the stator and the rotor. 
         [0019]    Preferably, a sleeve protrudes from the mounting bracket, and the stator is fixedly supported on the sleeve. 
         [0020]    Preferably, wherein the driving shaft is rotatably inserted in the sleeve. 
         [0021]    Preferably, wherein the base further comprises a rear cover, the rear cover is disposed at one side of the mounting bracket away from the stator, the actuator further comprises two supporting bearings for rotatably supporting the driving shaft, and the two supporting bearings are mounted to the rear cover and the mounting bracket close to the stator, respectively. 
         [0022]    Preferably, the driving shaft is connected with the pump body through an eccentric transmission assembly. 
         [0023]    Preferably, the transmission assembly comprises a bearing seat, a transmission bearing, and an eccentric bushing, the transmission bearing is mounted in the bearing seat, one side of the bearing seat is connected to the pump body, the eccentric bushing is fixedly sleeved on the driving shaft and rotatably mounted in the transmission bearing. 
         [0024]    Preferably, the eccentric bushing is cylindrical and defines a through hole, an axis of the eccentric bushing is offset from an axis of the through hole, the driving shaft passes through the through hole of the eccentric bushing such that the eccentric bushing rotates along with the driving shaft. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]      FIG. 1  is a perspective view of a pump according to a preferred embodiment of the present invention. 
           [0026]      FIG. 2  is a perspective, partly exploded view of the pump of  FIG. 1 . 
           [0027]      FIG. 3  is a perspective, exploded view of the pump of  FIG. 1 . 
           [0028]      FIG. 4  is a perspective, exploded view of the pump of  FIG. 1 , viewed from another aspect. 
           [0029]      FIG. 5  is a perspective view of a transmission assembly of  FIG. 2 . 
           [0030]      FIG. 6  is a sectional view of the pump of  FIG. 1 , taken along line Iv-IV thereof. 
       
    
    
       [0031]    Below, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0032]    The technical solutions of the embodiments of the present invention will be clearly and completely described as follows with reference to the accompanying drawings. Apparently, the embodiments as described below are merely part of, rather than all, embodiments of the present invention. Based on the embodiments of the present disclosure, any other embodiment obtained by a person skilled in the art without paying any creative effort shall fall within the protection scope of the present invention. 
         [0033]    It is noted that, when a component is described to be “fixed” to another component, it can be directly fixed to the another component or there may be an intermediate component. When a component is described to be “connected” to another component, it can be directly connected to the another component or there may be an intermediate component. When a component is described to be “disposed” on another component, it can be directly disposed on the another component or there may be an intermediate component. 
         [0034]    Unless otherwise specified, all technical and scientific terms have the ordinary meaning as understood by people skilled in the art. The terms used in this disclosure are illustrative rather than limiting. 
         [0035]    Referring to  FIG. 1  and  FIG. 2 , a pump  100  according to a preferred embodiment of the present invention includes a pump body  70  and an actuator to driving the pump body  70 . The actuator includes a base  10 , a motor  30  mounted to the base  10 , a transmission assembly  50  mounted around the motor  30 , and two supporting bearings  353 . The motor  30  includes a driving shaft  351  connecting with the transmission assembly  50 . 
         [0036]    In this embodiment, the base  10  is configured for enclosing the motor  30  and the transmission assembly  50  therein. The pump body  70  is mounted between the base  10  and the bottom support  80 . The bottom support  80  is used to support the whole pump  100  on a supporting surface. 
         [0037]    The base  10  includes a mounting bracket  12 , a front cover  14 , and a rear cover  15 . The front cover  14  and the rear cover  15  are mounted at opposite sides of the mounting bracket  12 . 
         [0038]    Referring also to  FIG. 3 , in this embodiment, the mounting bracket  12  is a plastic member being integrally formed as one piece, thus shortening the manufacturing process. In other embodiments, the mounting bracket  12  can also be a welding part or a spliced part made of a metal or alloy material through welding or bonding. The mounting bracket  12  includes a connecting board  123 , a base plate  124 , and a sleeve  125 . 
         [0039]    Referring also to  FIG. 4  and  FIG. 6 , the mounting bracket  12  defining a receiving chamber  121 , which is bounded by the connecting board  123  and the base plate  124 . The receiving chamber  121  is configured for accommodating the transmission assembly  50 . The connecting board  123  forms a plurality of catches  1231  and a plurality of engagement blocks  1232  at one side thereof opposite to the receiving chamber  121 . In this embodiment, the plurality of catches  1231  and the plurality of engagement blocks  1232  are separately arranged along a circumferential direction of the connecting board  123 . The connecting board  123  defines a through hole configured for the driving shaft passing therethough. A bearing jacket  1233  (shown in  FIG. 6 ) protrudes from one side of the connecting board  123  away from the plurality of catches  1231  around the through hole of the connecting board  123 . 
         [0040]    The base plate  124  is substantially perpendicular to the connecting board  123 . The base plate  124  defines a through hole  1241  with an axial direction perpendicular to the driving shaft  351 . The through hole  1241  communicates with the receiving chamber  121 . The pump body  70  is configured to be connected to the transmission assembly  50  via the through hole  1241 . 
         [0041]    In this embodiment, the sleeve  125  is substantially cylindrical. The sleeve  125  protrudes from one side of the connecting board  123  away from the receiving chamber  121 . The sleeve  125  defining an axial hole communicates with the bearing hole  1233 , to enable the driving shaft  351  to rotatably extend through the sleeve  125  and the bearing hole  1233 . The sleeve  125  forms at least one guiding member  1251  on an outer puerperal surface thereof. The guiding member  1251  extends along an axial direction of the sleeve  125 . The guiding members  1251  are provided to facilitate mounting the motor  30  around the sleeve  125  with a predetermined orientation. 
         [0042]    In this embodiment, the front cover  14  is substantially hollow cubic member with an opening  140  defined in a side thereof. The front cover  14  coves the motor  30  and is connected to the connecting board  123  with the opening  140  facing the connecting board  123 . The front cover  14  forms a plurality of catches  142  adjacent to and around the opening of the front cover  14  to be cooperatively engages with the engagement block  1232  to fixedly attach the front cover  14  to the connecting board  123 . It should be understood that the catches  142  can also be formed on the connecting board  123 , and correspondingly the blocks  1232  are formed on the front cover  14 . 
         [0043]    The rear cover  15  is mounted at one side of the mounting bracket  12  away from the motor  30  to close the receiving chamber  121 . The rear cover  15  defines a recess  150  in a side facing the mounting bracket  12  and a through hole  151  communicating with the recess, configured for rotatably receiving the driving shaft  351 . 
         [0044]    The motor  30  is an outer rotor motor, and includes a stator  31  supporting on the sleeve  125 , and a rotor  32  rotatably surrounding the stator and fixed to the driving shaft  351 . In one embodiment, the motor  30  is a brushless direct current motor, and further includes a controller  33 . In this embodiment, the stator  31  is an armature, which includes a core and windings wound around the core. The rotor  32  is an excitation assembly, which includes a plurality of permanent magnets. In should be understood that, in other embodiments, the stator  31  can also be an excitation assembly. Correspondingly, the rotor  32  can also be the armature. 
         [0045]    The stator  31  is mounted around the sleeve  125 . An inner surface of the stator  31  contacting the sleeve  125  forms a plurality of guiding grooves (not shown) mating with the guiding members  1251  to enable the stator attached to the sleeve  125  with a predetermined orientation. The rotor  32  is rotatably mounted around the stator  31 . The rotor  32  rotates about the stator  31  after the stator  31  is energized. In present invention, the controller  33  is based on a PCB, which defines a though hole provided for the sleeve  125  passing through. In this embodiment, the controller  33  is mounted between the connecting board  123  and the stator  31 . The plurality of catches  1231  engages with the controller  33  to fix the controller  33  at one side of the connecting board  123 . The controller  33  and the stator  31  are connected electrically, thereby providing electric power to the stator  31  and controlling power output of the motor  30  by controlling amplitude and direction of an electric current in the stator  31 . The controller  33  includes a wire  332  for connecting to an external power supply. 
         [0046]    Referring also to  FIG. 6 , the supporting bearings  353  are respectively mounted in the recess  150  of the rear cover  15 , and the bearing jacket  1233  of the mounting bracket  12 . A gasket  355  is disposed in the mounting groove  151  and sandwiched between the corresponding supporting bearing  353  and the rear cover  15 . In this embodiment, the gasket  355  is a corrugated gasket  355 , which is used to adjust a distance between the supporting bearing  353  and the end surface of the rear cover  15  and reduce vibration between the supporting bearing  353  and the rear cover  15 . One end of the driving shaft  351  is fixed to the rotor  32 , and the other end of the driving shaft  351  passes sequentially through the sleeve  125 , one of the two supporting bearings  353 , the transmission assembly  50 , and the other one of the two supporting bearings  353 . Therefore, the driving shaft  351  is rotatably supported by the sleeve  125  and the two supporting bearing  353 . 
         [0047]    The transmission assembly  50  includes a bearing seat  51 , a transmission bearing  53  mounted in the bearing seat  51 , and an eccentric bushing  55  mounted in the transmission bearing  53 . In this embodiment, the bearing seat  51  is generally annular and hollow, which forms a connector  511  at one side thereof for connecting with the pump body  70 . The transmission bearing  53  is fixed in the bearing seat  51 . The eccentric bushing  55  is fixedly sleeved on the driving shaft  351  and rotatably mounted in the transmission bearing. 
         [0048]    In this embodiment, the eccentric bushing  55  is cylindrical and defines a through hole for the driving shaft  351  passing therethrough. an axis of the eccentric bushing  55  is offset from an axis of the through hole  551 . In other words, a thicknesses of wall of the eccentric bushing  55  is ununiform along an peripheral direction thereof. 
         [0049]    In this embodiment, the pump body  70  is driven by the actuator for draining liquid. The pump body  70  includes a mating member  71 , a pushing assembly  73 , and a sealing ring  75 . The mating member  71  defines a chamber  712  and at least two passages  713   a  and  713   b  communicating with the chamber  712 . One end of each of the passages  713   a  and  713   b  communicates with the chamber  712 , and the other end of each of the passages  713   a  and  713   b  interfacing with a one-way valve (not shown), thereby forming inlet and outlet passages of the liquid. The pushing assembly  73  includes an linking member  731  and a pump head  733  adapted for coving the chamber  712 . One end of the linking member  731  is connected to the connector  511 , and the other end of the linking member  731  is connected to a generally central area of the pump head  733 . 
         [0050]    In this embodiment, the pump head  733  is made of an elastic material, and is generally disc-shaped. An outer diameter of the pump head  733  is greater than an outer diameter of the chamber  712 . An annular seal  7331  is disposed on the pump head  733  along a circumferential direction thereof. Opposite sides of the annular seal  7331  abut against the base plate  124  and the mating member  71 , respectively, such that the chamber  712  forms a sealed environment. The linking member  731  can force the pump head  733  to be deformed axially within a certain range, thus establishing a vacuum environment in an interior of the chamber  712 . The sealing ring  75  is disposed on the mating member  71  around the chamber  712 , for further enhancing the sealing effectiveness. 
         [0051]    The bottom support  80  is disposed at one side of the mating member  71  away from the base plate  124 . In this embodiment, the bottom support  80  is connected to the base plate  124  through a plurality of screws  81  which extends sequentially through the bottom support  80  and the mating member  71 . For fixing the bottom support  80  more filially, a backing plate  83  can be arranged between the bottom support  80  and the screws  81 . It should be understood that the backing plate  83  can also be an anti-loosening component such as a gasket or a washer. 
         [0052]    In assembly of the pump, an end of the linking member  731  with the pump head  733  mounted thereon is connected to the connector  511  via the through hole  1241  of the base plate  124 . The screws  81  extend sequentially through the bearing plate  83 , the bottom support  80 , and the mating member  71  to assemble the pump body  70  onto the base plate  124 . 
         [0053]    In use. the motor  30  is energized. The driving shaft  351  rotates with the rotor  32 . The eccentric bushing  55  rotates in synchronization with the driving shaft  351 . Since the eccentric bushing  55  has an asymmetric design, the eccentric bushing  55  drives the bearing seat  51  and the pushing assembly  73  connected to the bearing seat to move along an axial direction of the through hole  1241  back and forth. In particular, in a period of a rotation of the eccentric bushing  55  in which a thicker wall side of the eccentric bushing  55  is moved gradually closer to the base plate  124 , the eccentric bushing  55  drives the bearing seat  51  and the pushing assembly  73  towards the mating member  71 . In another period of the rotation of the eccentric bushing  55  in which a thinner wall side of the eccentric bushing  55  is moved gradually closer to the base plate  124 , the eccentric bushing  55  drives the bearing seat  51  and the pushing assembly  73  away from the mating member  71 . When the pushing assembly  73  moves away the mating member  71 , an air pressure in the chamber  712  is decreased to generate a suction force to draw the liquid through one of the one-way valves and the passages  713   a  into the chamber  712 ; When the pushing assembly  73  moves towards the mating member  71 , an air pressure in the chamber  712  is increased to drained out the liquid in the chamber through the other one-way valve and the passage  713   b , thus achieving the drainage of the liquid. 
         [0054]    Although the invention is described with reference to one or more embodiments, the above description of the embodiments is used only to enable people skilled in the art to practice or use the invention. It should be appreciated by those skilled in the art that various modifications are possible without departing from the spirit or scope of the present invention. The embodiments illustrated herein should not be interpreted as limits to the present invention, and the scope of the invention is to be determined by reference to the claims that follow.