WO2025251194A1 - Motor and electric pump using motor - Google Patents

Abstract

The present invention relates to a motor and an electric pump using the motor. The motor comprises a stator and a rotor. The stator comprises a housing and a stator magnetic core mounted to the inner wall of the housing. The rotor comprises a rotating shaft and a rotor core fixed to the rotating shaft; and the rotor core is surrounded by the stator magnetic core. The housing is an insulating member. The motor comprises a first conductive member; the first conductive member is conductively connected to the stator magnetic core; and the first conductive member has a first grounding portion extending beyond the housing and configured to be conductively connected to the outside. The motor further comprises a second conductive member and a circuit board mounted at one end of the motor; the second conductive member is conductively connected to a grounding position of the circuit board; and a part of the second conductive member is inserted into the stator and is conductively connected to the first conductive member. By implementing the present invention, even if the motor housing is an insulator, the stator magnetic core and the circuit board can be grounded by means of the first conductive member and the second conductive member, thereby improving the electromagnetic compatibility of the motor.

Description

An electric motor and an electric pump using the same motor Technical Field

This invention relates to an electric motor and an electric pump using the same motor.

Background Technology

Typically, a control circuit board is mounted at one end of the motor. This board is used to detect and control the motor's operation. Usually, the grounding point of the circuit board is connected to the motor housing via a conductive component, thus grounding the circuit board components and reducing electromagnetic interference (EMI). This approach requires the motor housing to be made of conductive metal, which is costly. Therefore, an improved solution is urgently needed.

Technical issues

One objective of this application is to reduce the cost of the motor and improve its electromagnetic interference.

Technical solutions

To this end, the present invention provides a first aspect of an electric motor, including a stator and a rotor; the stator includes a housing and a stator core mounted to the inner wall of the housing; the rotor includes a shaft and a rotor core fixed to the shaft, the rotor core being surrounded by the stator core; wherein: the housing is an insulating component; the electric motor includes a first conductive component, the first conductive component being electrically connected to the stator core, the first conductive component having a first grounding portion extending outside the housing for conductive connection to the outside; the electric motor further includes a second conductive component and a circuit board mounted to one end of the electric motor, the second conductive component being electrically connected to the grounding portion of the circuit board, a portion of the second conductive component being inserted into the stator and electrically connected to the first conductive component.

In one embodiment of the present invention, the first grounding portion is a free end and has elasticity to enhance the conductive connection with the outside.

In one embodiment of the present invention, the first conductive element is located between the inner wall of the housing and the outer surface of the stator core.

In one embodiment of the present invention, the outer surface of the stator core is provided with a groove, the groove extending along the axial direction of the motor; the first conductive member is installed in the groove and electrically connected to the stator core within the groove.

In one embodiment of the present invention, the first conductive member is provided with a locking structure, which cooperates with the groove and/or the outer shell to prevent the first conductive member from falling out of the groove.

In one embodiment of the present invention, the first conductive member includes a sheet-like main body portion, and the locking structure is a barb structure formed on the edge of the main body portion.

In one embodiment of the present invention, the first connecting portion of the first conductive member and the second connecting portion of the second conductive member form a conductive connection within the stator, wherein the second connecting portion is an end or middle portion of the second conductive member.

In one embodiment of the present invention, when the first connecting part and the second connecting part are connected, one of them elastically squeezes or elastically clamps the other to strengthen the conductive connection between the two.

In one embodiment of the present invention, one of the first connecting portion and the second connecting portion is provided with a slot, and the other is inserted into the slot in a tight fit manner.

In one embodiment of the present invention, the first conductive member is provided with a stepped or protruding limiting portion, which cooperates with the stator core or the outer shell to limit the depth of the first conductive member inserted into the stator.

In one embodiment of the invention, the second conductive member is fixed to the circuit board; the circuit board is substantially perpendicular to the rotating shaft.

In one embodiment of the present invention, the housing has an open end facing the circuit board; the motor includes a first end cap mounted to the open end, and the circuit board is housed within the first end cap; the housing and/or the first end cap are provided with mounting holes for fixing the motor to a preset position; the first end cap is provided with a connector for connecting to the circuit board.

In one embodiment of the invention, the first grounding portion extends beyond the outer peripheral surface of the housing, or extends beyond the axial end of the housing away from the circuit board.

In one embodiment of the present invention, the housing includes a bottom and an annular outer wall extending from the edge of the bottom, the stator core being mounted to the inner wall of the annular wall; the bottom is provided with a first support structure for supporting the rotation of the shaft.

In one embodiment of the invention, a second end cap is further included; the second end cap and the first end cap are respectively connected to the axial ends of the housing; the second end cap is provided with a second support structure for supporting the rotation of the shaft.

In one embodiment of the invention, the second end cap is also used to contain a load or a working head.

A second aspect of the present invention also provides an electric pump, including a pump housing and a motor provided in the first aspect of the present invention, wherein the pump housing is connected to the motor.

Beneficial effects

By implementing this invention, even if the motor casing is an insulator, the stator core can be grounded through the first conductive element, and the circuit board can be grounded through the second conductive element and the first conductive element. This reduces manufacturing costs and improves the electromagnetic compatibility of the motor.

Attached Figure Description

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

Figure 1 is a schematic diagram of a motor provided in an embodiment of the present invention;

Figure 2 is a longitudinal section schematic diagram of the motor shown in Figure 1;

Figure 3 is an explosion diagram of the motor shown in Figure 1;

Figure 4 is a schematic diagram of the stator core and the first end cover of the motor shown in Figure 1;

Figure 5 is a schematic diagram of the circuit board and the second conductive component installed inside the first end cover shown in Figure 4.

Figure 6 is a schematic diagram of the first transmission component used in the motor shown in Figure 1;

Figure 7 is a schematic diagram of the connection state of the first and second conductive components of the motor shown in Figure 1.

Embodiments of the present invention

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

Referring to Figures 1 to 3, an embodiment of the present invention provides a motor 100 including a stator and a rotor. The stator includes a housing 21 and a stator core 26 mounted to the inner wall of the housing 21. The stator core 26 includes an annular yoke, a plurality of teeth 27 extending inwardly from the yoke, and stator windings (not shown) wound around the teeth 27. The rotor includes a shaft 31 and a rotor core fixed to the shaft 31, the rotor core being surrounded by the stator core 26, specifically, the rotor core being surrounded by the teeth 27 of the stator core 26. In this embodiment, the rotor core includes a rotor core 33 and a permanent magnet 34 mounted to the rotor core 33. Understandably, the rotor core can be formed solely of the permanent magnet.

In this embodiment, the outer casing 21 is an insulating component; for example, the outer casing 21 is made of plastic to reduce manufacturing costs. The outer casing 21 includes a bottom 22 and an annular outer wall extending from the bottom edge, to which the stator core 26 is mounted. The bottom 22 is provided with a first support structure 23 for supporting the rotation of the rotating shaft 31. In this embodiment, the first support structure 23 is a bushing structure; understandably, the first support structure 23 could also be a bearing housing and a rolling bearing mounted to the bearing housing.

The motor 100 includes a first conductive member 61, which is electrically connected to the stator core 26. The first conductive member 61 has a first grounding portion 65 (see Figure 6) extending beyond the outer casing 21 for conductive connection to the outside. In this embodiment, the first grounding portion is a free end with appropriate elasticity to enhance the conductive connection to the outside. A certain gap is provided between the first grounding portion and the outer surface of the motor, allowing the first grounding portion to have radially inward elastic deformation space. With this structure, even if the outer casing 21 is an insulating component, the stator core 26 can still be grounded through the first conductive member 61, protecting the internal components of the motor and reducing electromagnetic interference to the outside.

The motor 100 also includes a second conductive member 51 and a circuit board 43 mounted to one end of the motor. The second conductive member 51 is electrically connected to the contact point of the circuit board 43. A portion of the second conductive member 51 is inserted into the stator and electrically connected to the first conductive member 61. Preferably, one end of the second conductive member 51 is inserted into the stator and electrically connected to the first conductive member 61; however, it is understood that a non-end portion of the second conductive member 51, such as the middle portion, can also be inserted into the stator and electrically connected to the first conductive member 61. With this structure, even if the housing 21 is an insulating component, the contact point of the circuit board 43 can be grounded through the second conductive member 51 and the first conductive member 61, protecting the internal components of the motor and reducing electromagnetic interference to the outside. The second conductive member 51 can be detachably inserted into the stator core 26, or it can be fixed to the stator core 26. For example, the second conductive member 51 can be injection molded into the stator core 26, becoming an integral part of the stator core 26 and not detachable. The second conductive member 51 and the first conductive member 61 are electrically connected by plugging in. Understandably, the second conductive member 51 and the first conductive member 61 can be detachably plugged in, or they can be fixedly connected after plugging in.

In this embodiment, the first conductive member 61 is located between the inner wall of the outer casing 21 and the outer surface of the stator core 26. The outer surface of the stator core 26 is provided with a groove 28, which extends along the axial direction of the motor. The first conductive member 61 is installed into the groove 28 and is electrically connected to the stator core 26 within the groove 28.

Referring to Figures 3 to 6, the main body of the first conductive member 61 is housed within the groove 28. In this embodiment, the stator core 26 is formed by stacking a plurality of stator laminations along the motor axial direction. The stator laminations have notches corresponding to the groove 28. Therefore, after the plurality of stator laminations are stacked, a groove 28 is formed that is radially concave and extends axially. Preferably, the axial cross-section of the groove 28 is square or trapezoidal. The first conductive member 61 is inserted axially into the groove 28 of the stator core 26. The first conductive member 61 is provided with a locking structure to prevent the first conductive member 61 from falling out of the groove 28. In this embodiment, the first conductive member 61 includes a sheet-like main body 62, and the locking structure is a barb structure 64 formed on both sides of the sheet-like main body 62. The main body 62 has its largest outer diameter at the position corresponding to the locking structure. This largest outer diameter is slightly larger than the groove width of the groove 28, so that the barb structure 64 and the groove 28 can form a tight or slightly tight fit connection, allowing the main body 62 to be stably housed in the groove 28. The barb structure 64 also forms a conductive connection with the sidewall of the groove 28 of the stator core 26. In this embodiment, the barb structure 64 has a guiding slope 64a and an anti-detachment slope 64b. The guiding slope helps the first conductive member 61 to be inserted into the groove 28 along a first direction, and the anti-detachment slope 64b prevents the first conductive member 61 from detaching from the groove 28 in a direction opposite to the first direction. Since the main body 62 is clamped between the outer shell 21 and the stator core 26, it is understandable that the locking structure of the main body 62, in conjunction with the outer shell 21 and/or the groove 28, can prevent detachment. The first conductive member 61 is also provided with a stepped or protruding limiting part 66. During the process of the first conductive member 61 being inserted into the groove 28 along the first direction, the limiting part 66 cooperates with the stator core 26 or the outer shell 21 to limit the depth of the first conductive member 61 inserted into the stator.

In this embodiment, the second conductive member 51 is fixed to the circuit board 43, and the circuit board 43 is substantially perpendicular to the rotating shaft 31. During assembly, the first conductive member 61 and the second conductive member 51 are inserted into the stator from the two shaft ends, respectively. The first connecting portion 67 of the first conductive member 61 and the second connecting portion 55 of the second conductive member 51 form a conductive connection within the stator.

Preferably, when the first connecting portion 67 and the second connecting portion 55 are connected, one of them elastically squeezes or elastically clamps the other to strengthen the conductive connection between them. As shown in Figures 6 and 7, in this embodiment, the first connecting portion 67 is provided with a slot 68, and the second connecting portion 55 is inserted into the slot 68 and elastically clamped by the slot 68 to form a tight fit connection. Specifically, the first connecting portion 67 forms two free arms 67a, which form a U-shaped slot 68. The ends of the free arms 67a have guide surfaces 67b near the slot 68, so that the slot 68 has a larger width at the entrance, which facilitates the insertion of the second connecting portion 55. After the second connecting portion 55 is inserted, its width is elastically clamped by the two free arms 67a. Correspondingly, the two free arms 67a are spread open to contact the sidewall of the groove 28 of the stator core 26 to form a conductive connection. Preferably, the main body 62 has arc-shaped notches 67c on both sides near the bottom of the slot 68, making it easier for the two free arms 67a to undergo elastic deformation. Understandably, the slot can also be provided at the second connecting part 55, and the slot is tightly connected to the first connecting part 67.

In this embodiment, the first conductive member 61 has a first bent portion 63 and a second bent portion 69 sequentially arranged between the main body portion 62 and the first grounding portion 65. The first bent portion 63 is bent radially outward, and the second bent portion 69 is bent axially downward. This gives the first grounding portion 65 greater elasticity and a greater tolerance to dimensional tolerances in the external environment. Similarly, the second conductive member 51 also has a third bent portion 53 and a fourth bent portion 59 sequentially arranged. The third bent portion 53 is bent radially outward, and the fourth bent portion 59 is bent axially downward, to increase the elasticity and dimensional tolerance of the second connecting portion 55.

Please refer back to Figures 1 to 3. In this embodiment, the housing 21 has an open end facing the circuit board 43. The motor 100 includes a first end cover 41 mounted to the open end. The circuit board 43 is housed within the first end cover 41. The first end cover 41 is provided with a connector 48 for connection to the circuit board 43. Specifically, the connector 48 is provided with a plurality of terminals 49 for conductive connection with corresponding positions on the circuit board 43.

The first end cap 41 includes a stacked outer cap 45 and an inner cap 46. The inner cap 46 is made of plastic and is connected to the outer casing 21 by laser welding to ensure internal sealing. The outer cap 45 is made of metal to improve the electromagnetic compatibility (EMC) level of the motor. The outer casing 21 and/or the first end cap 41 are provided with mounting holes 42 for fasteners to pass through, for fixing the motor 100 to a preset position. In this embodiment, both the metal outer cap 45 of the first end cap 41 and the outer casing 21 are provided with mounting holes 42 for fasteners to pass through. In one application, the preset position is a recessed hole. In use, the motor 100 shown in FIG. 1 is inserted into the recessed hole from top to bottom, and then a connector, such as a screw, passes through the mounting hole 42 to fix the motor 100 to the recessed hole. The first grounding portion 65 of the first conductive member 61 is electrically connected to the hole wall of the recessed hole, thereby achieving grounding. Preferably, the first grounding portion 65 extends beyond the outer peripheral surface of the housing 21, or extends beyond the axial end of the housing 21 away from the first end cap 41. The first grounding portion 65 is provided with a radially outward protrusion to further enhance the conductive connection with the outside.

In one embodiment, the motor 100 further includes a second end cover 71. The second end cover 71 and the first end cover 41 are respectively connected to the two axial ends of the housing 21. The second end cover 71 is provided with a second support structure 73 for supporting the rotation of the shaft 31. The second support structure 73 is a bushing structure or a rolling bearing structure.

In one embodiment, the second end cap 71 is also used to house a load or working head. For example, the motor 100 can be used as an electric pump, and the second end cap 71 serves as a pump housing or part of a pump housing, housing a load or working head. When the electric pump is used as an oil pump, it is fitted into a corresponding recessed space on a vehicle. The inner wall of this recessed space is conductive (or has conductive portions). After the oil pump is fitted, the first contact point 65 of the motor 100 is electrically connected to the conductive portion of the inner wall of the recessed space, thereby grounding the stator core 26 of the motor and the contact point of the circuit board 43. In this application, the first support structure 23 and the second support structure 73 can be bushing structures to simplify the overall structure.

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 (12)

An electric motor includes a stator and a rotor; the stator includes a housing and a stator core mounted to the inner wall of the housing; the rotor includes a shaft and a rotor core fixed to the shaft, the rotor core being surrounded by the stator core; characterized in that: The outer casing is an insulating component; The motor includes a first conductive element, which is electrically connected to the stator core. The first conductive element has a first grounding portion extending outside the housing for conductive connection with the outside. The motor also includes a second conductive element and a circuit board mounted to one end of the motor. The second conductive element is electrically connected to the contact point of the circuit board, and a portion of the second conductive element is inserted into the stator and electrically connected to the first conductive element. The motor as described in claim 1, wherein the first grounding portion is a free end and has elasticity to enhance the conductive connection with the outside. The motor as claimed in claim 1, wherein the first conductive member is located between the inner wall of the housing and the outer surface of the stator core. The motor as described in claim 1 is characterized in that the outer surface of the stator core is provided with a groove, the groove extending along the axial direction of the motor; the first conductive member is installed in the groove and electrically connected to the stator core within the groove. The motor as described in claim 4, wherein the first conductive member is provided with a locking structure, the locking structure cooperating with the groove and/or the housing to prevent the first conductive member from falling out of the groove. The motor as claimed in claim 5, wherein the first conductive member comprises a sheet-like main body portion, and the locking structure is a barb structure formed on the edge of the main body portion. The motor as described in claim 1 is characterized in that the first connecting portion of the first conductive member and the second connecting portion of the second conductive member form a conductive connection within the stator, wherein the second connecting portion is an end or middle portion of the second conductive member. The motor as described in claim 7 is characterized in that, when the first connecting part and the second connecting part are connected, one of them elastically squeezes or elastically clamps the other to strengthen the conductive connection between the two. The motor as described in claim 7 is characterized in that one of the first connecting portion and the second connecting portion is provided with a slot, and the other of the two portions is inserted into the slot in a tight fit manner. The motor as described in claim 7 is characterized in that the first conductive member is provided with a stepped or protruding limiting portion, the limiting portion cooperating with the stator core or the outer shell to limit the depth of the first conductive member inserted into the stator. The motor as claimed in claim 1, wherein the first grounding portion extends beyond the outer peripheral surface of the housing, or extends beyond the axial end of the housing away from the circuit board. An electric pump includes a pump housing, characterized in that it further includes a motor as described in any one of claims 1-11, wherein the pump housing is connected to the motor.