Electric motor and fluid pump using same

Abstract

The present invention relates to an electric motor and a fluid pump using same. The fluid pump comprises an electric motor and a pump body. The electric motor comprises an electric motor inner cavity for accommodating a rotor and a control module accommodating cavity for accommodating an electric motor control module, the control module comprising a circuit board assembly. The electric motor further comprises a control module housing for accommodating the control module and a thermally conductive first seal. The first seal separates the electric motor inner cavity from the control module accommodating cavity and is thermally conductively connected to the circuit board assembly for transferring heat from the circuit board assembly to fluid in the electric motor inner cavity. Terminals of the circuit board assembly pass through the first seal and are hermetically connected to the first seal. The control module housing surrounds the periphery of the first seal and is hermetically connected to the first seal. According to the present invention, the fluid entering the interior of the electric motor absorbs and carries away heat of the circuit board assembly, thereby achieving an improved heat dissipation effect.

Description

Electric motor and fluid pump using the electric motor

[0001] [Technical Field]

[0002] This invention relates to an electric motor and a fluid pump using the electric motor, the fluid pump being used as an oil pump in an automobile.

[0003] [Background Technology]

[0004] Motors typically include a control module, which usually comprises a circuit board, components mounted on the board, and circuitry, among which components often require heat dissipation. For example, the control chip generates significant heat and needs timely cooling. One existing heat dissipation solution is to transfer heat from the control module to an external heatsink, which then conducts the heat to an external object or dissipates it into the air through cooling fins. A drawback of this approach is its high cost. Therefore, an improved solution is urgently needed.

[0005] [Summary of the Invention]

[0006] A first aspect of this application provides an electric motor, including a stator, a rotor rotatably mounted to the stator, and a control module located at one end of the motor; the motor includes an inner cavity for housing the rotor and a control module receiving cavity for housing the control module; the control module includes a circuit board assembly; the motor further includes a control module housing housing the control module and a thermally conductive first seal, the first seal separating the inner cavity of the motor from the receiving cavity of the control module and being thermally connected to the circuit board assembly for transferring heat from the circuit board assembly to fluid within the inner cavity of the motor; terminals of the circuit board assembly pass through the first seal and are sealed to the first seal; at least a portion of the control module housing surrounds the outer periphery of the first seal and is sealed to the first seal to prevent the circuit board assembly from contacting the fluid.

[0007] In one embodiment of the present invention, a second sealing member is further included, which wraps around the outer periphery of the terminal and forms a sealed connection with the terminal; the first sealing member is sealed to the outer periphery of the second sealing member; at least one of the first sealing member and the second sealing member is an insulating member.

[0008] In one embodiment of the present invention, the second seal extends a predetermined length along the motor axial direction and protrudes relative to the first seal toward the inner cavity of the motor.

[0009] In one embodiment of the invention, the outer periphery of the second seal is provided with a groove for enhancing the seal, and the first seal extends into the groove. In another embodiment of the invention, the second seal is first formed onto the outer periphery of the terminal; the first seal is formed onto the outer periphery of the first seal and the surface of the circuit board assembly.

[0010] In one embodiment of the present invention, there are multiple second sealing elements, each used to seal the outer periphery of the corresponding terminal; the multiple second sealing elements are either discretely formed or formed into a whole.

[0011] In one embodiment of the present invention, a heat-conducting element is further included, which is located between the circuit board assembly and the first seal, for conducting heat from the circuit board assembly to the first seal; the heat-conducting element may be one or a plurality of discrete elements.

[0012] In one embodiment of the invention, the stator or the rotor includes windings, and the terminals include power supply terminals and / or ground terminals for supplying power to the windings.

[0013] In one embodiment of the present invention, the rotor includes a rotating shaft, a rotor core fixedly sleeved on the rotating shaft, and a permanent magnet fixed to the rotor core; the stator includes a stator core and a stator winding, the stator core including a plurality of stator teeth arranged around the rotor core, and the winding being wound around the corresponding stator teeth; the terminal includes a power supply terminal for supplying power to the stator winding.

[0014] In one embodiment of the present invention, the stator core is provided with a plurality of axial grooves; the terminal includes a grounding terminal, the free end of which is inserted into the groove in a tight-fit or slightly tight-fit manner and forms a conductive connection with the stator core.

[0015] In one embodiment of the present invention, the motor includes a motor housing, the stator core is installed inside the motor housing; the circuit board assembly and the first seal are located at the rear end of the motor; the rotating shaft extends from the front end of the motor and is rotatably supported at the front end.

[0016] In one embodiment of the present invention, a shielding cover is provided inside the control module housing, the shielding cover surrounding or covering the circuit board assembly; the shielding cover has a grounding portion for grounding.

[0017] In a second aspect, the present invention provides a fluid pump, including a motor and a pump body driven by the motor; the motor is a motor as described above; fluid driven by the pump body can flow into the motor and contact a first seal to receive heat transferred from the circuit board assembly via the first seal.

[0018] In one embodiment of the invention, the motor housing of the motor surrounds the stator; the pump body includes a pump housing that is fitted onto and sealed to the motor housing to prevent the fluid from flowing outside the motor housing.

[0019] In one embodiment of the invention, a support plate is further included between the motor and the pump body, the support plate being fixed to the motor housing or the pump housing; the rotor shaft is rotatably supported on the support plate, one end of the shaft extending from the support plate into the motor to receive the motor output, and the other end extending from the support plate into the pump body to drive the pump body.

[0020] In one embodiment of the present invention, the support plate is provided with through holes for fluid to flow between the inside of the pump body and the inside of the motor.

[0021] In one embodiment of the present invention, the rotating shaft is provided with an axial through hole for the fluid to flow between the inside of the pump body and the inside of the motor.

[0022] In one embodiment of the present invention, fluid can enter the rear end of the motor from the pump body through the axial through hole of the shaft and contact the first seal, and return to the pump body through the gap between the motor stator and rotor and the through hole of the support plate.

[0023] In one embodiment of the present invention, fluid can enter the rear end of the motor from the pump body through the through hole of the support plate and the gap between the motor stator and rotor, and contact the first seal, and return to the pump body through the axial through hole of the rotating shaft.

[0024] Compared with traditional heat dissipation solutions that use external heat sinks, this invention absorbs and carries the heat from the circuit board components through fluid entering the motor, resulting in better heat dissipation.

[0025] [Attached Image Description]

[0026] To further reveal the specific technical content of this case, please first refer to the accompanying drawings, in which:

[0027] Figure 1 is a schematic diagram of a fluid pump provided in an embodiment of the present invention;

[0028] Figure 2 is a schematic diagram of the operating status of the fluid pump shown in Figure 1;

[0029] Figure 3 is a top view of the fluid pump described in Figure 1;

[0030] Figure 4 is a schematic diagram of the AA cross-section of the fluid pump shown in Figure 3;

[0031] Figure 5 is a schematic diagram of the fluid pump shown in Figure 1 after the control module housing has been removed;

[0032] Figure 6 is a schematic diagram of the fluid pump shown in Figure 1 after the control module housing and pump housing have been removed.

[0033] Figure 7 is a schematic diagram of the removal of the controller housing, pump housing, and motor housing of the fluid pump shown in Figure 1;

[0034] Figure 8 is a schematic diagram of the assembly of the motor circuit board assembly, the first seal, and the second seal of the fluid pump shown in Figure 1.

[0035] Figure 9 is a schematic diagram of the assembly shown in Figure 8 after the first seal has been removed;

[0036] Figure 10 is a schematic diagram of the assembly shown in Figure 8 after the first seal and circuit board assembly have been removed.

[0037]

Detailed Implementation Methods

[0038] The technical solutions in the embodiments of the present invention will now be described with reference to the accompanying drawings.

[0039] Referring to Figure 1, a fluid pump 100 provided in one embodiment of the present invention includes a motor 20 and a pump body 70, wherein the motor 20 drives the pump body 70. The pump body 70 is mounted to the front end of the motor 20 (i.e., the output end of the motor). In this embodiment, the pump housing 71 of the pump body 70 and the motor housing 21 of the motor 20 are fastened together by a snap-fit ​​device. The motor housing 21 is provided with an elastic connecting arm 26, which has a locking hole; the pump housing 71 is provided with a locking block 76 with a guide surface. When the pump housing 71 is fastened to the motor housing 21, the locking block 76 slides into the locking hole of the connecting arm 26, thereby realizing the snap-fit ​​connection. Understandably, the pump housing 71 and the motor housing 21 can also be fixedly connected by fasteners such as screws or bolts.

[0040] The pump casing 71 is provided with fluid inlets and outlets 73, 74 and 75. When the fluid pump 100 is working, fluid enters the pump casing 70 from the corresponding fluid inlets and outlets and exits from the corresponding fluid inlets and outlets.

[0041] Referring to Figures 1 and 2, the fluid pump 100 is installed at the corresponding workstation 110 during use. The workstation 110 has a receiving cavity 112 to receive the fluid pump 100, and more specifically, to receive the pump body 70. The motor housing 21 includes an outwardly extending mounting portion 23, which has mounting holes 24 for fasteners to pass through, so as to fix the fluid pump 100 to the workstation 110.

[0042] The motor 20 is exposed outside the workstation 110. In this embodiment, the rear end of the motor 20 is provided with a control module housing 31, a connector 33 disposed in the control module housing 31, and a control module housed inside the control module housing 31. Fasteners pass through the connection holes 28 of the motor housing 21 and are fixedly connected to the control module housing 31.

[0043] Referring to Figures 1 and 4, the motor 20 has a control module housing cavity 32 for housing the control module and a motor inner cavity 92 for housing the motor rotor. In this embodiment, the control module housing 31 forms the control module housing cavity 32. The control module housing 31 is provided with a breathing membrane to balance the air pressure inside the control module housing cavity 32, and a breathing valve cover 35 is provided at the position corresponding to the breathing membrane to protect the breathing membrane from direct external impact. The control module includes a circuit board assembly housed in the control module housing 31: a circuit board 41, and components 42, 43, etc. disposed on the circuit board 41. The terminals 34 of the connector 33 are electrically connected to the corresponding pads of the circuit board 41. The connector 33 is used to connect to an external power source to supply power to the fluid pump 100.

[0044] Referring to Figures 3 to 10, the stator of the motor 20 includes a stator core 55 and a stator winding 58. The stator core 55 includes an annular yoke 56 and a plurality of stator teeth 57 extending inward from the yoke 56, with slots formed between adjacent stator teeth 57. The stator winding 58 is wound around the corresponding stator teeth 57 and housed in the corresponding slots. The rotor of the motor 20 includes a shaft 65, a rotor core 67 fixedly sleeved on the shaft 65, and a permanent magnet 68 fixed to the rotor core 67. The rotor is rotatably mounted to the stator, and the plurality of stator teeth 57 surround the rotor core 67. Understandably, there is a gap 91 between the outer periphery of the rotor core 67 and the stator teeth 57 of the stator to allow the rotor to rotate relative to the stator.

[0045] The fluid inside the pump body 70 can enter the space inside the motor 20, such as the motor cavity 92, including the gap 91 between the stator core 55 and the rotor core 67, and the space 93 between the stator core 55 and the circuit board assembly.

[0046] The stator of the motor 20 also includes a thermally conductive first seal 46, which separates the motor cavity 92 from the control module housing cavity 32. The first seal 46 is thermally connected to the circuit board assembly and can contact the fluid inside the motor 20, transferring heat from the circuit board assembly to the fluid. Thus, heat emitted by the circuit board 41 and its components 42, 43, etc., can be conducted to the fluid inside the motor 20 through the first seal 46, and then dissipated to the outside by the fluid when the fluid pump 100 is operating. Compared to conventional heat dissipation solutions using external heat sinks, this invention absorbs and carries heat from the circuit board assembly through the fluid inside the motor 20, resulting in better heat dissipation. Furthermore, it eliminates the need for a traditional external heat sink, reducing the size of the motor 20 or the fluid pump 100.

[0047] Furthermore, since the present invention dissipates heat through the fluid inside the motor 20, it no longer relies on the outer casing and heat sink to dissipate heat to the outside. Therefore, the control module housing 31, the motor housing 21, and the pump housing 71 can all be made of plastic parts, which can further reduce costs.

[0048] Terminals 44 and 45 of the circuit board assembly pass through the first seal 46 and are sealed to it. In this embodiment, terminal 45 is a grounding terminal and is electrically connected to the stator core 55. In this embodiment, the outer peripheral surface of the yoke 56 of the stator core 55 is provided with several grooves 56a, which extend along the motor axial direction. Terminal 45 is plate-shaped, and the width of its free end is slightly larger than the width of the groove 56a, so that it can be slightly fitted with the two side walls of the groove 56a, thereby achieving mechanical and conductive connection with the stator core 55. Preferably, the free end of terminal 45 has a barbed structure, which facilitates the insertion of the free end of terminal 45 into the groove 56a and prevents it from falling out easily. Terminal 44 is a power supply terminal and is electrically connected to the corresponding line end of the stator winding 58 for supplying power to the stator winding 58. In this embodiment, terminal 44 includes UVW terminals 44a, 44b, and 44c, which are electrically connected to the corresponding line ends of the stator winding 58, respectively.

[0049] Because terminals 44a, 44b, 44c, and 45 are sealed to the first seal 46, fluid inside the motor 20 will not penetrate into the circuit board 41.

[0050] The control module housing 31 is cap-shaped, with its open end snapped onto the motor housing 21. At least a portion of the control module housing 31 surrounds the outer periphery of the first seal 46 and is sealed to the first seal 46, preventing the control module or circuit board assembly inside the control module housing 31 from contacting the fluid inside the motor 20. In this embodiment, a first sealing ring 49 is provided between the outer periphery of the first seal 46 and the inner wall of the control module housing 31 for a sealed connection between the two.

[0051] Referring to Figures 4, 8 to 10, to enhance the sealing connection between terminals 44a, 44b, 44c, and 45 and the first sealing member 46, a corresponding second sealing member 47 is preferably added. In this embodiment, the second sealing member 47 includes second sealing members 47a, 47b, 47c, and 47d, which respectively wrap around the outer periphery of terminals 44a, 44b, 44c, and 45 to form a sealing connection. The number of second sealing members is the same as the number of terminals passing through the first sealing member 46. If there are two or more second sealing members, these two or more can be discretely formed or formed into a whole through the connecting part 47c. Preferably, each second sealing member 47a, 47b, 47c, and 47d extends a predetermined distance along the motor axial direction to increase its sealing area with the corresponding terminal, thereby improving the sealing performance. In this embodiment, the lengths of each of the second seals 47a, 47b, 47c, and 47d along the motor axial direction are greater than the axial dimension of the second seal 47. Each of the second seals 47a, 47b, 47c, and 47d protrudes relative to the first seal 46 toward the pump body 70. More preferably, each of the second seals 47a, 47b, 47c, and 47d is provided with a groove 47f for reinforcing the seal, into which the first seal 46 extends to strengthen the sealing connection.

[0052] At least one of the first seal 46 and the second seal 47 is an insulator. In this embodiment, the second seal 47 is an insulator, formed from insulating plastic by overmolding onto the outer periphery of the corresponding terminal. As shown in FIG10, in this embodiment, each of the second seals 47a, 47b, 47c and 47d forms a whole through the connecting portion 47e, thereby connecting with the corresponding terminal as a whole. Referring to FIG3 and FIG8, the first seal 46 is overmolded onto the outer periphery of each sealing portion 47a, 47b, 47c and 47d and the surface of the circuit board 41 facing the motor cavity 92. For example, the sealing portion 46a of the first seal 46 covers the outer periphery of the second seal 47a and forms a sealed connection. The other sealing portions 46b to 46d of the first seal 46 are similar and will not be described in detail. The sealing portion 46e of the first seal 46 covers the circuit board 41 and its components, such as component 43. Preferably, the second seal 47 is formed of a thermally and electrically conductive material, and the electrically conductive material generally has better thermal conductivity, thereby improving the thermal conductivity of the first seal 46.

[0053] Referring to Figure 4, the stator of the motor 20 also includes a heat-conducting element 48, which is located between the inner side of the circuit board assembly and the first seal 46 to enhance heat conduction. The heat-conducting element 48 can be formed of thermally conductive adhesive, cast or filled into the inner side of the circuit board assembly and located between the inner side of the circuit board assembly and the first seal 46. The heat-conducting element 48 can be a single unit or several discrete parts. Components 42 and 43 of the circuit board assembly can be disposed on the same side of the circuit board 41 or on different sides. Preferably, components with high heat generation are disposed on the inner side of the circuit board 41 to facilitate better heat conduction to the first seal 46.

[0054] In this embodiment, the control module housing 31 includes a shielding cover 31a disposed on the inner side, which surrounds or covers the circuit board assembly. Preferably, the shielding cover 31a has a grounding portion for grounding. The outer surface of the control module housing 31 can be a plastic shell 31b to reduce costs and achieve a sealed connection with the motor housing 21. Understandably, although the motor housing 21 and the control module housing 31 are detachably connected in this embodiment, the present invention is not limited to this situation. In alternative embodiments, the motor housing 21 and the control module housing 31 can be a single piece.

[0055] A support plate 51 is provided at the front end of the motor 20. The support plate 51 is fixed relative to the motor housing 21. A hub 52 is provided at the center of the support plate 51 for rotatably supporting the rotor shaft 65. The outer end of the shaft 65 extends outward from the front end of the motor 20 and enters the pump body 70 to drive the pump body 70. The inner end of the shaft 65 extends into the motor 20 from the front end to receive the output of the motor 20.

[0056] The pump housing 71 of the pump body 70 is fitted onto the motor housing 21 and is sealed to prevent fluid from flowing out of the motor housing 21. In this embodiment, the main body of the motor housing 21 is cylindrical, and the pump housing 71 is cap-shaped. The open end of the pump housing 71 is fitted onto the motor housing 21, and the two are sealed together by a second sealing ring 29. In this embodiment, the support plate 51 is located inside the open end of the pump housing 71 and is connected to the pump housing 71 by an axial screw 77. The main components of the pump body 70 are housed between the bottom plate of the pump housing 71 and the support plate 51, including, for example, a cam 81 driven by a rotating shaft 65, and a gear ring 83 surrounding the cam 81 and driven by the cam 81.

[0057] A limiting plate 85 can also be added to the remote motor 20 end of the pump body 70. The limiting plate 85 is connected to the internal body of the pump body 70 through the connector 78 to prevent the cam 81, gear ring 83, etc. from falling off.

[0058] The pump casing 71 has a space 95 that communicates with the internal space of the motor 20, such as the aforementioned gap 91 and space 93, allowing fluid to flow inside the motor 20 and the pump body 70. Preferably, the support plate 51 has several through holes to allow fluid to flow between the inside of the pump body 70 and the inside of the motor 20.

[0059] In this embodiment, the rotating shaft 65 is provided with an axial through hole 66 to allow fluid to flow between the inside of the pump body 70 and the inside of the motor 20. Preferably, the fluid inside the pump body 70 enters the rear end of the motor 20 through the axial through hole 66 of the rotating shaft 65, for example, the space 93 between the stator and the first seal 46, and returns to the front end of the pump body 70 from the outside of the rotating shaft 65, for example, the gap 91 between the stator and the rotor, and the groove 59 between the stator teeth 57, through the through hole of the support plate 51, and flows out of the fluid pump 100. Understandably, the opposite fluid flow direction or other flow directions can also be designed. For example, the fluid inside the pump body 70 enters the rear end of the motor 20 through the through hole of the support plate 51, the gap 91 between the stator and the rotor, and the groove 59 between the stator teeth 57, for example, the space 93 between the stator and the first seal 46, and returns to the front end of the pump body 70 through the axial through hole 66 of the rotating shaft 65, and flows out of the fluid pump 100.

[0060] The pump body 70 of the present invention is preferably used for pumping non-conductive liquids.

[0061] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An electric motor, comprising a stator, a rotor rotatably mounted to the stator, and a control module located at one end of the motor; the motor includes a motor cavity for receiving the rotor and a control module receiving cavity for receiving the control module; the control module includes a circuit board assembly, characterized in that: It also includes a control module housing that houses the control module and a thermally conductive first seal, the first seal separating the motor cavity from the control module housing cavity and being thermally connected to the circuit board assembly for transferring heat from the circuit board assembly to the fluid inside the motor cavity; the terminals of the circuit board assembly pass through the first seal and are sealed to the first seal. At least a portion of the control module housing surrounds the outer periphery of the first seal and is sealed to the first seal to prevent the circuit board assembly from contacting the fluid.

2. The electric machine of claim 1, wherein, It also includes a second seal, the outer periphery of which wraps around the terminal and forms a sealed connection with the terminal; the first seal is sealed to the outer periphery of the second seal; at least one of the first seal and the second seal is an insulating element.

3. The electric machine of claim 2, wherein, The second seal extends a predetermined length along the motor axis and protrudes relative to the first seal toward the inner cavity of the motor.

4. The electric machine of claim 2, wherein, The second seal has a groove on its outer periphery for enhancing the seal, and the first seal extends into the groove.

5. The electric machine of claim 2, wherein, The second seal is first formed onto the outer periphery of the terminal; the first seal is formed onto the outer periphery of the second seal and the surface of the circuit board assembly.

6. The electric machine of claim 2, wherein, There are several second seals, each used to seal the outer periphery of the corresponding terminal; the several second seals are either discretely formed or formed into a whole.

7. The electric machine of claim 1, wherein, It also includes a heat-conducting component, which is located between the circuit board assembly and the first seal, for conducting heat from the circuit board assembly to the first seal; the heat-conducting component may be one or multiple discrete components.

8. The electric machine of claim 1, wherein, The stator or the rotor includes windings, and the terminals include power supply terminals and / or grounding terminals for supplying power to the windings.

9. The electric machine of claim 1, wherein, The rotor includes a shaft, a rotor core fixedly sleeved on the shaft, and a permanent magnet fixed to the rotor core; the stator includes a stator core and a stator winding, the stator core including a plurality of stator teeth arranged around the rotor core, and the winding being wound around the corresponding stator teeth; the terminal includes a power supply terminal for supplying power to the stator winding; the stator core is provided with a plurality of axial grooves; the terminal includes a grounding terminal, the free end of which is inserted into the groove in a tight-fit or slightly tight-fit manner and forms a conductive connection with the stator core.

10. The electric machine of claim 9, wherein, The rotor includes a shaft, a rotor core fixedly sleeved on the shaft, and a permanent magnet fixed to the rotor core; the stator includes a stator core and stator windings, the stator core including a plurality of stator teeth arranged around the rotor core, and the windings wound around corresponding stator teeth; the terminals include power terminals for supplying power to the stator windings; the motor includes a motor housing, and the stator core is installed inside the motor housing; the circuit board assembly and the first seal are located at the rear end of the motor; the shaft extends from the front end of the motor and is rotatably supported at the front end.

11. The electric machine of claim 1, wherein, The control module housing has a shielding cover inside, which surrounds or covers the circuit board assembly; the shielding cover has a grounding part for grounding.

12. A fluid pump comprising a motor and a pump body driven by the motor; characterized in that, The motor is the motor described in any one of claims 1 to 11; the fluid driven by the pump can flow into the motor and contact the first seal to receive the heat transferred from the circuit board assembly via the first seal.

13. The fluid pump of claim 12, wherein, The motor housing surrounds the stator; the pump body includes a pump housing that is fitted onto and sealed to the motor housing to prevent the fluid from flowing outside the motor housing.

14. The fluid pump of claim 13, wherein, It also includes a support plate located between the motor and the pump body, the support plate being fixed to the motor housing or the pump housing; the rotor shaft is rotatably supported on the support plate, one end of the shaft extending from the support plate into the motor to receive the motor output, and the other end extending from the support plate into the pump body to drive the pump body.

15. The fluid pump as claimed in claim 14, characterized in that: The support plate is provided with through holes to allow fluid to flow between the inside of the pump body and the inside of the motor; and / or The rotating shaft is provided with an axial through hole for the fluid to flow between the inside of the pump body and the inside of the motor.

16. The fluid pump as claimed in claim 14, characterized in that: Fluid can enter the rear end of the motor from the pump body through the axial through-hole of the shaft and contact the first seal, and then return to the pump body through the gap between the motor stator and rotor and the through-hole of the support plate; or Fluid can enter the rear end of the motor from the pump body through the through hole of the support plate and the gap between the motor stator and rotor, and contact the first seal, and return to the pump body through the axial through hole of the shaft.

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