An electric pump

Abstract

The application relates to an electric pump, which comprises a circuit board, a bottom cover, a motor shell and a sealing part, the circuit board comprises a first surface and a second surface, the circuit board comprises a guide hole, the guide hole penetrates through the first surface and the second surface, the bottom cover comprises a guide part, the guide part is in clearance fit with the guide hole, the bottom cover has a sealing groove, the bottom cover comprises an outer peripheral surface, the sealing groove is recessed from the outer peripheral surface to a direction close to a central axis of the electric pump, in the radial direction of the electric pump, at least part of the sealing part is located between a groove wall forming the sealing groove and the motor shell; the guide part comprises a guide end surface, in the axial direction of the electric pump, the guide end surface is away from the first surface relative to the second surface, and the minimum distance from the sealing part to the second surface is smaller than the minimum distance from the sealing part to the guide end surface. The application has the characteristics of improving the sealing effect of the electric pump.

Description

Technical Field

[0001] This application relates to the fields of lubrication and / or refrigeration, and more particularly to an electric pump for vehicles. Background Technology

[0002] An electric pump includes a motor housing, a sealing part, and an end cover. The sealing part is located in a groove in the end cover, and the end cover is sealed to the motor housing through the sealing part. If the position of the sealing part is misaligned during the assembly of the end cover, the assembly accuracy of the sealing part will be low, resulting in poor sealing performance of the electric pump. Therefore, improving the sealing performance of an electric pump is a technical problem. Utility Model Content

[0003] This application provides an electric pump that improves the sealing performance of the electric pump.

[0004] To achieve the above objectives, this application adopts the following technical solution:

[0005] An electric pump includes a circuit board, a bottom cover, a motor housing, and a sealing portion. The circuit board includes a first surface and a second surface, and a guide hole extending through the first surface and the second surface. The bottom cover includes a guide portion that is clearance-fitted with the guide hole. The bottom cover has a sealing groove. In the radial direction of the electric pump, at least a portion of the sealing portion is located between the groove wall forming the sealing groove and the motor housing. The guide portion includes a guide end face. In the axial direction of the electric pump, the guide end face is located away from the first surface relative to the second surface. The motor housing has a first end face that contacts the bottom cover. The minimum distance from the first end face to the first surface is less than the minimum distance from the sealing portion to the guide end face.

[0006] In the above technical solution, in the radial direction of the electric pump, at least part of the sealing part is located between the groove wall forming the sealing groove and the motor housing. The guide part includes a guide end face. In the axial direction of the electric pump, the guide end face is far away from the second face relative to the first face. The motor housing has a first end face that contacts the bottom cover. The distance from the first end face to the first face is less than the minimum distance from the sealing part to the guide end face. When assembling the bottom cover, the guide part is pre-inserted into the guide hole, which can circumferentially limit the bottom cover. This helps to reduce the relative movement between the sealing part and the motor housing in the circumferential direction, thereby improving the assembly accuracy of the sealing part and thus improving the sealing effect of the electric pump. Attached Figure Description

[0007] Figure 1 This is a schematic diagram of the electric pump of this application from one perspective;

[0008] Figure 2 for Figure 1 Schematic diagram of the BB section;

[0009] Figure 3 for Figure 1 A schematic diagram of the C-section;

[0010] Figure 4 for Figure 3 An enlarged schematic diagram of section E in the middle;

[0011] Figure 5 This is a schematic diagram showing the connection between the bottom cover and the circuit board;

[0012] Figure 6 This is a schematic diagram of one embodiment of the bottom cover;

[0013] Figure 7 for Figure 6 A schematic diagram of the FF section;

[0014] Figure 8 This is a schematic diagram of another embodiment of the bottom cover;

[0015] Figure 9 This is a schematic diagram of another embodiment of the bottom cover;

[0016] Figure 10 This is a schematic diagram of another embodiment of the bottom cover;

[0017] Figure 11 for Figure 10 A schematic diagram of the bottom cover from another perspective.

[0018] Reference numerals: 1. Pump housing; 11. Pump cover; 12. Motor housing; 121. First inner circumference; 122. Second inner circumference; 123. Third inner circumference; 124. First end face; 13. Bottom cover; 131. Body; 1311. Sealing groove; 1311a. Groove wall; 1312. Guide portion; 13121. Guide end face; 13122. Arc portion; 13123. Flat portion; 13124. Transition portion; 13125. Cylindrical portion; 13126. Chamfered portion; 13127. First part; 13128. Second part ; 1313, Outer peripheral surface; 1314, Second end face; 1315, Inner peripheral surface; 1316, Receiving groove; 1317, Fixing part; 1318, Connecting part; 132, Pin; 1321, Pin end face; 2, Sealing part; 4, Pump rotor; 41, Inner rotor; 42, Outer rotor; 5, Stator assembly; 51, Stator core; 52, Winding; 6, Motor rotor; 7, Pump shaft; 8, Electrical control assembly; 81, Circuit board; 811, First surface; 812, Second surface; 813, Guide hole; 10, Pump chamber; 20, Motor chamber. Detailed Implementation

[0019] To enable those skilled in the art to better understand this application, the embodiments of this application are further described in detail below. Obviously, the embodiments described below are merely some embodiments of this application, and those skilled in the art can obtain other embodiments based on these embodiments without creative effort.

[0020] Electric pumps can be applied to automotive lubrication and / or cooling systems, providing circulating power for the working medium in these systems, which in turn provide lubricating oil and / or cooling oil to the transmission system. In this application, "A and B fixed connection" means that there is no relative displacement between A and B after the connection, such as A and B being welded together; "A and B limiting connection" means that A restricts B's movement in a certain direction, or B restricts A's movement in a certain direction.

[0021] Please refer to Figures 1 to 11The electric pump includes a pump housing 1, which includes a pump cover 11 and a motor housing 12. The pump cover 11 is fixedly connected to the motor housing 12, for example, by screws or bolts. Alternatively, the pump cover 11 and motor housing 12 can be connected by other methods, such as plug-in or snap-fit ​​connections. Referring to the figure, the electric pump also includes a bottom cover 13, which is fixedly connected to the motor housing 12, for example, by screws or bolts. This connection facilitates easy assembly and disassembly of the electric pump. The electric pump includes a pump rotor 4, a stator assembly 5, a motor rotor 6, a pump shaft 7, and an electrical control assembly 8. The motor rotor 6 is located radially inside the stator assembly 5 and is drively connected to the pump rotor 4. The pump rotor 4 includes an inner rotor 41 and an outer rotor 42. The inner rotor 41 includes multiple external teeth, and the outer rotor 42 includes multiple internal teeth. The outer rotor 42 is located on the outer periphery of the inner rotor 41, and the inner rotor 41 and the outer rotor 42 are internally meshed. In other embodiments, the inner rotor 41 and the outer rotor 42 are externally meshed, in which case the outer rotor 42 and the inner rotor 41 are arranged side by side. In this embodiment, the central axis of the outer rotor 42 is offset from the central axis of the inner rotor 41, that is, there is a certain eccentricity between the central axis of the outer rotor 42 and the central axis of the inner rotor 41. When the inner rotor 41 rotates, at least some of the external teeth of the inner rotor 41 mesh with at least some of the internal teeth of the outer rotor 42, thereby enabling the inner rotor 41 to drive the outer rotor 42 to rotate. The stator assembly 5 includes a stator core 51 and windings 52. When the electric pump is working, the electronic control assembly 8 controls the current in the windings 52 of the stator assembly 5 to change according to a predetermined pattern, thereby controlling the stator assembly 5 to generate a changing excitation magnetic field. The motor rotor 6 rotates under the action of the excitation magnetic field. The motor rotor 6 can directly or indirectly drive the pump rotor 4 to rotate. In this embodiment, the pump shaft 7 is drivenly connected to the pump rotor 4 and the motor rotor 6. Specifically, one end of the pump shaft 7 is drivenly connected to the inner rotor 41, and the other end of the pump shaft 7 is drivenly connected to the motor rotor 6. The motor rotor 6 drives the inner rotor 41 to rotate through the pump shaft 7, thereby realizing the rotation of the pump rotor 4. It should be noted that the axial direction of the electric pump here and below is the direction of axial extension of the pump shaft 7, the central axis of the electric pump is the central axis of the pump shaft 7, the radial direction of the electric pump is the direction perpendicular to the axial direction of the electric pump, "radial outer" is the direction away from the central axis of the pump shaft 7, and "radial inner" is the direction close to the central axis of the pump shaft 7.

[0022] Please refer to Figure 1The electric pump has a pump chamber 10 and a motor chamber 20, which are connected. The pump rotor 4 (or at least part of the pump rotor 4) is located in the pump chamber 10, and the motor rotor 6 (or at least part of the motor rotor 6), at least part of the pump shaft 7, the stator assembly 5 (or at least part of the stator assembly 5) and the electrical control assembly 8 are located in the motor chamber 20. When the electric pump is working, the pump chamber 10 can have a working medium, and at least part of the working medium in the pump chamber 10 flows into the motor chamber 20, which can dissipate heat from the stator assembly 5 and the electrical control assembly 8.

[0023] Please refer to Figures 1 to 11 The electric pump includes a circuit board 81, a bottom cover 13, a motor housing 12, and a sealing part 2. Specifically, the electrical control assembly 8 includes a circuit board 81. The bottom cover 13 is fixedly connected to the motor housing 12. The circuit board 81 includes a first surface 811 and a second surface 812. The circuit board 81 includes a guide hole 813 that penetrates the first surface 811 and the second surface 812. The bottom cover 13 includes a guide part 1312 that is clearance-fitted with the guide hole 813. There is a gap between the guide part 1312 and the circuit board 81 to prevent the circuit board 81 from being damaged by force during the assembly of the bottom cover 13. The bottom cover 13 has a sealing groove 1311. At least a portion of the sealing portion 2 is located between the groove wall 1311a forming the sealing groove 1311 and the motor housing 12; the guide portion 1312 includes a guide end face 13121, which is located away from the first surface 811 relative to the second surface 812 in the axial direction of the electric pump; the motor housing 12 has a first end face 124, which contacts the bottom cover 13; the distance D1 from the first end face 124 to the first surface 811 is less than the minimum distance D2 from the groove wall 1311a to the guide end face 13121. When assembling the bottom cover 13, if the initial deviation between the guide part 1312 and the guide hole 813 is large, the guide part 1312 will continuously correct itself as the bottom cover 13 moves, causing the bottom cover 13 to rotate. This may scratch the sealing part 2 and cause leakage in the electric pump. By setting the distance D1 from the first end face 124 to the first face 811 to be less than the minimum distance D2 from the groove wall 1311a to the guide end face 13121, the guide part 1312 can pass through the guide hole 813 on the circuit board 81 to circumferentially limit the bottom cover. This helps reduce the relative movement between the sealing part and the motor housing in the circumferential direction, thereby improving the assembly accuracy of the sealing part 2 and thus improving the sealing effect of the electric pump. In this application, when the electric pump is working, the motor cavity 20 can contain working medium. By setting the sealing part 2 in the sealing groove 1311, it is beneficial to prevent the working medium in the motor cavity 20 from leaking out. In one embodiment, the bottom cover 13 includes an outer peripheral surface 1313, and a sealing groove 1311 is recessed from the outer peripheral surface 1313 toward the direction close to the central axis of the electric pump.

[0024] The bottom cover 13 includes a second end face 1314, which extends from the outer peripheral surface 1313 toward the central axis of the electric pump. At least a portion of the guide portion 1312 protrudes from the second end face 1314, and there is a gap between the guide portion 1312 and the outer peripheral surface 1313 in the radial direction of the electric pump. When assembling the bottom cover 13, the guide portion 1312 can be closer to the sealing portion 2, which is beneficial to improving the guiding effect of the guide portion 1312 and also helps to avoid assembly interference between the bottom cover 13 and the motor housing 12.

[0025] Please refer to Figure 6 and Figure 8 The guide portion 1312 includes an arc portion 13122, which faces the central axis of the electric pump and is clearance-fitted with the guide hole 813. The relatively large mating area between the arc portion 13122 and the guide hole 813 facilitates the insertion of the guide portion 1312 into the guide hole 813. In some embodiments, please refer to... Figure 8 The guide portion 1312 includes a flat portion 13123, which is connected to the arc portion 13122; in some embodiments, please refer to Figure 6 The guide portion 1312 includes a flat portion 13123 and a transition portion 13124. The transition portion 13124 connects the flat portion 13123 and the arc portion 13122. From the second end face 1314 to the guide end face 13121, the width of the transition portion 13124 gradually decreases. On the one hand, the perimeter of the guide hole 813 that mates with the guide portion 1312 can be relatively small, which is beneficial for the arrangement of electronic components on the circuit board 81; on the other hand, it is beneficial for ensuring the strength of the guide portion 1312 and the size control of the guide portion 1312. In one embodiment, please refer to... Figure 10 and Figure 11 The guide portion 1312 includes a cylindrical portion 13125 and a chamfered portion 13126. In the axial direction of the electric pump, the chamfered portion 13126 extends from the cylindrical portion 13125 in a direction away from the circuit board 81. The cylindrical portion 13125 is clearance-fitted with the guide hole 813, and the chamfered portion 13126 has a guide end face 13121. When assembling the bottom cover 13, the chamfered portion 13126 first passes through the guide hole 813, playing a positioning and guiding role during assembly. The bottom cover 13 can be continuously aligned during press-fitting, which helps ensure the relative position of the bottom cover 13 and the motor housing 12.

[0026] Please refer to Figure 5 , Figure 6 , Figure 9 and Figure 10When assembling the bottom cover 13, the guide part 1312 may exert a certain force on the circuit board 81. The electric pump includes at least two guide parts 1312. The guide parts 1312 are evenly or non-uniformly distributed along the circumferential direction of the bottom cover 13. The at least two guide parts 1312 are symmetrically arranged, which is conducive to the uniform force on the circuit board 81, thereby preventing the circuit board 81 from being damaged. In addition, after the guide part 1312 cooperates with the circuit board 81, it is conducive to preventing the bottom cover 13 from rotating, thereby preventing the bottom cover 13 from moving relative to the motor housing 12 in the circumferential direction.

[0027] Please refer to Figures 3 to 11 The bottom cover 13 includes a pin 132, which is electrically connected to the circuit board 81. The pin 132 includes a pin end face 1321. In the axial direction of the electric pump, the distance D3 from the pin end face 1321 to the first surface 811 is less than the distance D4 from the guide end face 13121 to the first surface 811. When assembling the bottom cover 13, if the sealing part 2 has been squeezed by the motor housing 12 before the guide part 1312 is inserted into the guide hole 813, the bottom cover 13 may shift due to the friction between the sealing part 2 and the motor housing 12 after the guide part 1312 is inserted into the guide hole 813. This may cause the position of the pin 132 to shift from the circuit board 81. The assembly accuracy of the pin 132 is low, and the distance D3 from the pin end face 1321 to the first surface 811 is less than the distance D4 from the guide end face 13121 to the first surface 811. The guide part 1312 inserted into the guide hole 813 on the circuit board 81 can circumferentially limit the bottom cover 13, which helps to reduce the relative movement of the pin 132 and the motor housing 12 in the circumferential direction, improves the assembly accuracy of the pin 132, and thus improves the electrical connection stability between the pin 132 and the circuit board 81.

[0028] Please refer to Figures 5 to 11 In the radial direction of the electric pump, the pin 132 is closer to the central axis of the electric pump relative to the guide portion 1312. The shortest distance D5 from the pin 132 to the outer peripheral surface 1313 is greater than or equal to the shortest distance D6 from the guide portion 1312 to the outer peripheral surface 1313. The guide portion 1312 is closer to the outer peripheral surface 1313 relative to the pin 132, and consequently, the guide hole 813 is also closer to the outer peripheral surface 1313 relative to the pin 132. The guide hole 813 is near the edge of the circuit board 81 or located at the edge of the circuit board 81. The circuit board 81 can have a large area for mounting electronic components. Furthermore, when assembling the bottom cover 13, the guide portion 1312 may exert a certain force on the circuit board 81. The force-bearing position on the circuit board 81 is near the edge of the circuit board 81 or located at the edge. When the circuit board 81 is subjected to multiple forces, the force can be evenly distributed, thereby preventing damage to the circuit board 81. The aforementioned edge refers to the outer perimeter of the circuit board.

[0029] Please refer to Figures 3 to 11The bottom cover 13 includes an inner circumferential surface 1315, and a sealing groove 1311 is recessed from the outer circumferential surface 1313 towards the inner circumferential surface 1315. In the radial direction of the electric pump, at least a portion of the guide portion 1312 protrudes from the inner circumferential surface 1315. In the radial direction of the electric pump, when the distance from the inner circumferential surface 1315 to the outer circumferential surface 1313 is small, i.e., the width of the second end face 1314 is small, if the radial width of the guide portion 1312 is less than or equal to the radial width of the second end face 1314, due to the large ratio of the axial height to the radial width of the guide portion 1312, it is prone to buckling under external force, thus easily breaking. In the radial direction of the electric pump, at least a portion of the guide portion 1312 protrudes from the inner circumferential surface 1315. When the bottom cover 13 is an injection molded part, uneven shrinkage occurs during the injection molding process as it changes from a liquid to a solid state. The guide portion 1312 is provided corresponding to the sealing groove 1311, which can reduce the internal stress formed during shrinkage and relatively reduce the amount of shrinkage when the sealing groove 1311 is formed by injection molding from liquid to solid state. This is beneficial for controlling the size of the sealing groove 1311 of the bottom cover 13, and thus helps to improve the fit between the sealing groove 1311 and the sealing portion 2. Secondly, the ratio of the axial height of the portion of the guide portion 1312 protruding from the second end face 1314 to its radial width is small. The guide portion 1312 is less prone to buckling when subjected to external force, which helps to improve the strength of the guide portion 1312. Specifically, the guide portion 1312 includes a first portion 13127 and a second portion 13128. The first portion 13127 is connected to the second portion 13128. The first portion 13127 extends from the second end face 1314 in a direction away from the second end face 1314. The first portion 13127 is clearance-fitted with the guide hole 813. In the radial direction of the electric pump, the second portion 13128 protrudes from the inner circumferential surface 1315. The second portion 13128 is provided corresponding to the sealing groove 1311, which can reduce the internal stress formed during shrinkage and relatively reduce the amount of shrinkage when the sealing groove 1311 is formed by injection molding from liquid to solid state. This is beneficial for controlling the size of the sealing groove 1311 of the bottom cover 13, and thus helps to improve the fit between the sealing groove 1311 and the sealing portion 2. Secondly, the ratio of the axial height to the radial width of the first portion 13127 is relatively small, so the guide portion 1312 is less likely to buckle when subjected to external force, which helps to improve the strength of the guide portion 1312.

[0030] Please refer to Figures 5 to 11 The bottom cover 13 includes a receiving groove 1316, the groove wall forming the receiving groove 1316 includes an inner peripheral surface 1315, the bottom cover 13 includes a fixing part 1317, the pin 132 is connected to the fixing part 1317, the fixing part 1317 is located in the receiving groove 1316, and the fixing part 1317 is directly or indirectly connected to the inner peripheral surface 1315. In one embodiment, please refer to... Figure 9The bottom cover 13 includes a connecting portion 1318, which extends from the inner circumferential surface 1315 to the fixing portion 1317. In the radial direction of the electric pump, there is a gap between the second portion 13128 and the fixing portion 1317. The connecting portion 1318 and the second portion 13128 are separately arranged. The second portion 13128 is arranged corresponding to the sealing groove 1311, which can reduce the internal stress formed during shrinkage and relatively reduce the shrinkage amount when the sealing groove 1311 is formed by injection molding from liquid to solid state. This is beneficial to controlling the size of the sealing groove 1311 of the bottom cover 13, and thus improving the fit between the sealing groove 1311 and the sealing portion 2. At the same time, when the bottom cover 13 is deformed due to temperature, the reaction force of the sealing portion 2 on the bottom cover 13 can be transmitted to the fixing portion 1317 through the connecting portion 1318, which to a certain extent helps to reduce the deformation of the bottom cover 13. In other embodiments, the connecting portion 1318 and the second portion 13128 are integrally formed, that is, the second portion 13128 extends from the inner circumferential surface 1315 to the fixing portion 1317. When the bottom cover 13 deforms due to temperature, the reaction force of the sealing portion 2 on the bottom cover 13 can be transmitted to the fixing portion 1317 through the second portion 13128, which to a certain extent helps to reduce the deformation of the bottom cover 13. In addition, it can relatively reduce the material used for the bottom cover 13, thereby reducing the production cost of the bottom cover 13. In other embodiments, please refer to Figure 8 The fixing part 1317 extends from the inner circumferential surface 1315 toward the direction close to the central axis of the electric pump. When the bottom cover 13 deforms due to temperature, the reaction force of the sealing part 2 on the bottom cover 13 is directly transmitted to the fixing part 1317, which to a certain extent helps to reduce the deformation of the bottom cover 13. In addition, it can relatively reduce the material used in the bottom cover 13, thereby reducing the production cost of the bottom cover 13.

[0031] Please refer to Figures 5 to 11 The bottom cover 13 includes a body portion 131 and pins 132, which are fixedly connected. In this embodiment, the body portion 131 and pins 132 are integrally formed. The body portion 131 is a plastic part, and at least a portion of the pins 132 are embedded in the body portion 131. The body portion 131 has a sealing groove 1311 and includes a guide portion 1312. The pins 132 and the guide portion 1312 are integrally formed, and the relative positions of the guide portion 1312 and the pins 132 are fixed, which helps to reduce the assembly error between the pins 132 and the circuit board 81.

[0032] Please refer to Figures 5 to 11The inner wall of the motor housing 12 includes a first inner peripheral portion 121, a second inner peripheral portion 122, and a third inner peripheral portion 123. The second inner peripheral portion 122 extends from the first inner peripheral portion 121 to the third inner peripheral portion 123. The inner diameter of the first inner peripheral portion 121 is larger than the inner diameter of the third inner peripheral portion 123. The sealing portion 2 contacts the first inner peripheral portion 121. If the inner diameter of the first inner peripheral portion 121 is equal to the inner diameter of the third inner peripheral portion 123, the circuit board 81 may scratch the first inner peripheral portion 121 when assembling it. After installing the sealing portion 2, leakage may occur between the first inner peripheral portion 121 and the sealing portion 2, which may cause micro-leakage in the electric pump. In this application, the inner diameter of the first inner peripheral portion 121 is larger than that of the third inner peripheral portion 123. When assembling the circuit board 81, there is a gap between the circuit board 81 and the first inner peripheral portion 121, which helps to ensure the sealing performance between the sealing portion 2 and the first inner peripheral portion 121, thereby helping to ensure the sealing performance of the electric pump. In the radial direction of the electric pump, the distance from the guide portion 1312 to the first inner peripheral portion 121 is greater than the distance from the guide portion 1312 to the third inner peripheral portion 123. When the bottom cover 13 is assembled, the distance between the guide portion 1312 and the first inner peripheral portion 121 is relatively large, and the guide portion 1312 will not damage the first inner peripheral portion 121. This is beneficial to ensuring the sealing performance between the sealing portion 2 and the first inner peripheral portion 121, thereby ensuring the sealing performance of the electric pump. In addition, if the guide hole 813 is located at the edge of the circuit board 81, there is a gap between the circuit board 81 and the first inner peripheral portion 121. When the electric pump is working, the working medium can flow from the first surface 811 of the circuit board 81 through the gap to the second surface 812 of the circuit board 81, which is beneficial to heat dissipation of the circuit board 81. There is a gap between the guide portion 1312 and the third inner peripheral portion 123. When the bottom cover 13 is assembled, it helps to prevent the guide portion 1312 from scratching the third inner peripheral portion 123, or helps to prevent the guide portion 1312 from breaking under force when it contacts the third inner peripheral portion 123, thus reducing the yield rate of the electric pump.

[0033] The above examples illustrate the principles and implementation methods of this application. The descriptions of the embodiments are merely for the purpose of helping to understand the methods and core ideas of this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of this application.

Claims

1. An electric pump characterized in that, The electric pump includes a circuit board (81), a bottom cover (13), a motor housing (12), and a sealing part (2). The circuit board (81) includes a first surface (811) and a second surface (812). The circuit board (81) includes a guide hole (813) that penetrates the first surface (811) and the second surface (812). The bottom cover (13) includes a guide part (1312) that is clearance-fitted with the guide hole (813). The bottom cover (13) has a sealing groove (1311). In the radial direction of the electric pump, at least a portion of the sealing part (2) is located in the area forming the sealing groove. Between the groove wall (1311a) of the sealing groove (1311) and the motor housing (12); the guide portion (1312) includes a guide end face (13121), in the axial direction of the electric pump, the guide end face (13121) is away from the first surface (811) relative to the second surface (812), the motor housing (12) has a first end face (124), the first end face (124) contacts the bottom cover (13), and the distance (D1) from the first end face (124) to the first surface (811) is less than the minimum distance (D2) from the groove wall (1311a) to the guide end face (13121).

2. The electric pump according to claim 1, characterized in that, The bottom cover (13) includes an outer peripheral surface (1313) and a second end surface (1314). The sealing groove (1311) is recessed from the outer peripheral surface (1313) toward the direction close to the central axis of the electric pump. The second end surface (1314) extends from the outer peripheral surface (1313) toward the direction close to the central axis of the electric pump. At least a portion of the guide portion (1312) protrudes from the second end surface (1314). In the radial direction of the electric pump, there is a gap between the guide portion (1312) and the outer peripheral surface (1313).

3. The electric pump according to claim 2, characterized in that, The guide portion (1312) includes an arc portion (13122) facing the central axis of the electric pump, and the arc portion (13122) is clearance-fitted with the guide hole (813).

4. The electric pump according to claim 3, characterized in that, The guide portion (1312) includes a flat portion (13123) connected to the arc portion (13122); or, the guide portion (1312) includes a flat portion (13123) and a transition portion (13124) connecting the flat portion (13123) and the arc portion (13122), and the width of the transition portion (13124) gradually decreases from the second end face (1314) to the guide end face (13121).

5. The electric pump of claim 1, wherein The guide portion (1312) includes a cylindrical portion (13125) and a chamfered portion (13126). In the axial direction of the electric pump, the chamfered portion (13126) extends from the cylindrical portion (13125) in a direction away from the circuit board (81). In the radial direction of the electric pump, the width of the chamfered portion (13126) is smaller than the width of the cylindrical portion (13125). The cylindrical portion (13125) is clearance-fitted with the guide hole (813). The chamfered portion (13126) has the guide end face (13121).

6. The electric pump of claim 2, wherein The guide portion (1312) includes a cylindrical portion (13125) and a chamfered portion (13126). In the axial direction of the electric pump, the chamfered portion (13126) extends from the cylindrical portion (13125) in a direction away from the circuit board (81). In the radial direction of the electric pump, the width of the chamfered portion (13126) is smaller than the width of the cylindrical portion (13125). The cylindrical portion (13125) is clearance-fitted with the guide hole (813). The chamfered portion (13126) has the guide end face (13121).

7. The electric pump according to any one of claims 1 to 6, characterized in that The electric pump includes at least two guide portions (1312), which are evenly or non-uniformly distributed along the circumferential direction of the bottom cover (13), and the at least two guide portions (1312) are symmetrically arranged.

8. The electric pump according to any one of claims 1 to 6, characterized in that The bottom cover (13) includes a pin (132) which is electrically connected to the circuit board (81). The pin (132) includes a pin end face (1321). In the axial direction of the electric pump, the distance (D3) from the pin end face (1321) to the first surface (811) is less than the distance (D4) from the guide end face (13121) to the first surface (811).

9. The electric pump according to claim 7, characterized in that, The bottom cover (13) includes a pin (132) which is electrically connected to the circuit board (81). The pin (132) includes a pin end face (1321). In the axial direction of the electric pump, the distance (D3) from the pin end face (1321) to the first surface (811) is less than the distance (D4) from the guide end face (13121) to the first surface (811).

10. The electric pump of claim 8, wherein, In the radial direction of the electric pump, the pin (132) is close to the central axis of the electric pump relative to the guide portion (1312), the bottom cover (13) includes an outer peripheral surface (1313), the sealing groove (1311) is recessed from the outer peripheral surface (1313) towards the central axis of the electric pump, and the shortest distance from the pin (132) to the outer peripheral surface (1313) is greater than or equal to the shortest distance from the pin (132) to the guide portion (1312).

11. The electric pump of claim 9, wherein In the radial direction of the electric pump, the pin (132) is close to the central axis of the electric pump relative to the guide portion (1312), the bottom cover (13) includes an outer peripheral surface (1313), the sealing groove (1311) is recessed from the outer peripheral surface (1313) towards the central axis of the electric pump, and the shortest distance from the pin (132) to the outer peripheral surface (1313) is greater than or equal to the shortest distance from the pin (132) to the guide portion (1312).

12. The electric pump of claim 8, wherein, The bottom cover (13) includes a body part (131), the body part (131) includes the guide part (1312), and the body part (131) and the pin (132) are integrally structured.

13. The electric pump of claim 9, wherein, The bottom cover (13) includes a body part (131), the body part (131) includes the guide part (1312), and the body part (131) and the pin (132) are integrally structured.

14. The electric pump of claim 10, wherein, The bottom cover (13) includes a body part (131), the body part (131) includes the guide part (1312), and the body part (131) and the pin (132) are integrally structured.

15. The electric pump of claim 11, wherein, The bottom cover (13) includes a body part (131), the body part (131) includes the guide part (1312), and the body part (131) and the pin (132) are integrally structured.

16. The electric pump of claim 2, wherein The bottom cover (13) includes an inner peripheral surface (1315), the sealing groove (1311) is recessed from the outer peripheral surface (1313) toward the inner peripheral surface (1315), and at least a portion of the guide portion (1312) protrudes from the inner peripheral surface (1315).

17. The electric pump of claim 10, wherein, The bottom cover (13) includes an inner peripheral surface (1315), the sealing groove (1311) is recessed from the outer peripheral surface (1313) toward the inner peripheral surface (1315), and at least a portion of the guide portion (1312) protrudes from the inner peripheral surface (1315).

18. The electric pump of claim 11, wherein, The bottom cover (13) includes an inner peripheral surface (1315), the sealing groove (1311) is recessed from the outer peripheral surface (1313) toward the inner peripheral surface (1315), and at least a portion of the guide portion (1312) protrudes from the inner peripheral surface (1315).

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