Embodiments of the present disclosure provide a rotor, a motor, a powertrain, and a vehicle. The rotor includes wedges and pole shoes. The wedges fit the pole shoes through curved portions. The curved portions can effectively relieve stress concentration of joint portions, increase strength of the wedges and the pole shoes, and effectively increase effective winding space of slots in the rotor. In this way, power density of a motor in which the rotor is used is increased.

TECHNICAL FIELD

Embodiments of the present disclosure relate to the field of motor technologies, and in particular, to a rotor, a motor, a powertrain, and a vehicle.

BACKGROUND

A motor is an electromagnetic apparatus that implements electric energy conversion or transfer according to the law of electromagnetic induction, and a main function of the motor is to generate drive torque as a power source of power-consuming devices or various machines. With development of miniaturization of a motor in a powertrain, power density of the motor increases gradually. An excitation motor mainly includes a housing and a front cover plate and a rear cover plate that are located at two ends of the housing. The front cover plate, the rear cover plate, and an inner wall of the housing jointly form a sealed cavity. A stator, a rotor, a rotating shaft, and windings (also referred to as coils) are disposed in the cavity. One end of the rotating shaft extends out of the housing from the front cover plate, the other end of the rotating shaft rotates relative to the rear cover plate, the rotor is sleeved on the rotating shaft, the stator is sleeved on an outer circumference of the rotor, the rotor includes a rotor core and windings disposed around the rotor core, and the stator includes a stator core and coils disposed around the stator core.

A salient-pole motor is used as an example. More windings can be disposed on a rotor of the salient-pole motor, and torque density and power density of the motor can be increased. A pole shoe of a salient-pole rotor fits a wedge accommodated in a slot, to protect the windings and prevent the windings from flying and being damaged under action of centrifugal force when the rotor rotates at a high speed.

As requirements for power density of the motor become higher, requirements for the wedge and the pole shoe become higher. To increase power density of the motor, more windings need to be accommodated. Therefore, effective winding space of the slot needs to be as large as possible, and the wedge and the pole shoe need to be as small as possible. The wedge and the pole shoe need to ensure sufficient strength in a case of a smaller size. Therefore, how to design the rotor becomes an urgent technical problem to be resolved.

SUMMARY

Embodiments of the present disclosure provide a rotor, a motor, a powertrain, and a vehicle. The rotor includes wedges and pole shoes. The wedges fit the pole shoes through curved portions. The curved portions can effectively relieve stress concentration of joint portions, increase strength of the wedges and the pole shoes, and effectively increase effective winding space of slots in the rotor. In this way, power density of a motor in which the rotor is used is increased.

According to a first aspect, an embodiment of the present disclosure provides a rotor, including: a rotor core, a plurality of slots, and a rotating shaft. Each slot includes one wedge, and rotor windings are wound in each slot. The rotor core is sleeved on the rotating shaft, and the plurality of slots are disposed at intervals along a circumferential direction of the rotor core. The rotor core includes a rotor core body and a plurality of pole shoes, and the plurality of pole shoes are disposed at intervals along a circumferential direction of the rotor core body. The pole shoe includes a pole shoe body and two symmetrical hook-shaped pole shoe end portions. The hook-shaped pole shoe end portion becomes thinner along a circumferential direction relative to the pole shoe body and includes at least one first curved portion. The wedge includes a wedge body and two symmetrical first wedge portions, each first wedge portion includes at least one second curved portion, and each first wedge portion fits one hook-shaped pole shoe end portion of one of the pole shoes.

To implement fitting between the first wedge portion and the first curved portion, the at least one second curved portion included in the first wedge portion needs to be in pairs with the at least one first curved portion of the hook-shaped pole shoe end portion.

It should be noted that a “curved portion” in this embodiment of the present disclosure may be alternatively replaced with a circular arc, a curve, a curved surface, a circular arc surface, an arc surface, or an arc. For example, a convex curved portion may also be referred to as a convex circular arc, a convex curved surface, a convex arc surface, or a convex arc; and a concave curved portion may also be referred to as a concave circular arc, a concave curved surface, a concave arc surface, or a concave arc. This is not limited herein.

In this embodiment of the present disclosure, the wedges fit the pole shoes through curved portions. The curved portions can effectively relieve stress concentration of joint portions, increase strength of the wedges and the pole shoes, and effectively increase effective winding space of the slots in the rotor. In this way, strength of the wedges and the pole shoes is increased, a maximum speed of the motor can also be increased, and power density of the motor is increased.

With reference to the first aspect, in some implementations, the first curved portion includes a first concave curved portion and/or a first convex curved portion; and the first wedge portion includes a second convex curved portion and/or a second concave curved portion. The first concave curved portion of the first curved portion fits the second convex curved portion of the first wedge portion, and/or the first convex curved portion of the first curved portion fits the second concave curved portion of the first wedge portion.

Optionally, the first curved portion may include one or more first concave curved portions, one or more first convex curved portions, and/or one or more line segments. The first wedge portion may include one or more second concave curved portions, one or more second convex curved portions, and/or one or more line segments. The first wedge portion separately fits first curved portions in hook-shaped pole shoe end portions of two adjacent pole shoes.

The first wedge portion fits the first curved portions through a plurality of curved portions, to further relieve stress concentration of the joint portions, increase strength of the wedges and the pole shoes, and effectively increase the effective winding space of the slots wound in the rotor. In this way, strength of the wedges and the pole shoes is increased, a maximum speed of the motor can also be increased, and power density of the motor is increased.

With reference to the first aspect, in some implementations, the pole shoe further includes a second pole shoe portion, and the second pole shoe portion is connected to the first curved portion. The second pole shoe portion is in an eccentric circular arc shape, and a center position of the eccentric circular arc shape does not coincide with an axis center of the rotating shaft; or the second pole shoe portion is in an arc shape of an air gap secant function.

Optionally, one or more concave curved portions, one or more convex curved portions, and/or one or more line segments may be further included between the second pole shoe portion and the first curved portion. The second pole shoe portion is connected to the first curved portion through the foregoing structure.

The foregoing pole shoe structure is used, so that torque fluctuation of the motor in which the pole shoe is used can be effectively reduced, and performance of noise, vibration, and harshness (NVH) of the motor can be improved.

With reference to the first aspect, in some implementations, an air gap length of the second pole shoe portion satisfies δ(θ)=δ0·sec θ, where δ(θ) represents the air gap length of the second pole shoe portion, δ0represents an air gap length at a position of a symmetry line of a pole arc curve in the pole shoe, and θ represents a circumferential angle between a radial line on which the second pole shoe portion is located and the symmetry line of the pole shoe. There is an air gap between an outer circumferential surface of the rotor core and an inner cavity wall of a stator. The pole arc curve encloses a main area in which the pole shoe faces an air gap.

With reference to the first aspect, in some implementations, the pole shoe further includes a third pole shoe portion, and the third pole shoe portion includes one or more third concave curved portions. The third pole shoe portion is tangent to the first curved portion, the third pole shoe portion is tangent to the second pole shoe portion, and the third pole shoe portion is used to extend a circumferential length of the pole shoe. In this way, the pole shoe can accommodate more rotor windings, and torque density and power density of the motor in which the rotor is used are increased.

Optionally, the third pole shoe portion may further include one or more line segments and one or more third concave curved portions.

With reference to the first aspect, in some implementations, the wedge body is used to isolate rotor windings on two sides, so that the wedge performs an insulation function. The wedge may be made of an insulation material.

With reference to the first aspect, in some implementations, the wedge further includes a second wedge portion, the second wedge portion is formed between the two first wedge portions, and the second wedge portion includes at least one concave curved portion. Two sides of the second wedge portion each are connected to one pair of first wedge portions. The second wedge portion is in an arc surface shape, so that stress concentration in an area of an arc surface can be relieved, and strength of the wedge can be increased.

With reference to the first aspect, in some implementations, the wedge further includes one or more pairs of third wedge portions; each pair of third wedge portions are symmetrically located on two sides of the wedge body; each pair of third wedge portions are symmetrical along a symmetry axis of the wedge; and the third wedge portion includes one or more circular arc curved portions and/or one or more line segments. The circular arc curved portion may be a convex curved portion, or may be a concave curved portion, or may be a combination of a convex curved portion and a concave curved portion. This is not limited herein. Bonding strength between the wedge and potting compound is increased through the third wedge portion, and stability of the rotor is improved.

With reference to the first aspect, in some implementations, when the wedge includes the plurality of pairs of third wedge portions, the plurality of pairs of third wedge portions are different in size and/or shape. In this way, strength of the wedge is increased, and stability of the rotor is further improved.

With reference to the first aspect, in some implementations, the wedge further includes a fourth wedge portion, and a radial bottom of the wedge body includes the fourth wedge portion. The rotor core further includes a first rotor core portion. The first rotor core portion radially faces toward the slot. A plurality of first rotor core portions are disposed at intervals along a circumferential direction of the rotor core body. The fourth wedge portion fits the first rotor core portion, to implement connection between the wedge and the rotor core. In this way, strength of a joint portion between the wedge and the rotor core is increased, and stability of the rotor is further improved.

With reference to the first aspect, in some implementations, the slot is filled with the potting compound. The potting compound is bonded to the wedge, the potting compound is bonded to the pole shoe, and the potting compound is bonded to the rotor windings. The wedges, the pole shoes, the rotor windings, and the rotor core inside the rotor are solidified as a whole by using the potting compound. In this way, strength of the rotor is increased, and stability of the rotor is improved.

According to a second aspect, an embodiment of the present disclosure provides a motor, including a stator and the rotor according to any one of the implementations of the first aspect. The stator is sleeved on an outer circumference of a rotor core of the rotor, and stator windings are disposed on the stator. Wedges fit pole shoes through curved portions. The curved portions can effectively relieve stress concentration of joint portions, increase strength of the wedges and the pole shoes, and effectively increase effective winding space of slots in the rotor. In this way, strength of the wedges and the pole shoes is increased, a maximum speed of the motor can also be increased, and power density of the motor is increased. The motor is an excitation motor.

According to a third aspect, an embodiment of the present disclosure provides a powertrain, including the motor according to any one of the foregoing implementations of the first aspect. The motor ensures that the powertrain keeps high efficiency in various running statuses.

With reference to the third aspect, in some implementations, the powertrain further includes a controller and a reducer. The controller is connected to the motor, the reducer is connected to the motor, the controller is configured to control working of the motor, and the reducer is configured to control a rotation speed of the motor.

According to a fourth aspect, an embodiment of the present disclosure provides a vehicle. The vehicle includes a vehicle frame and the motor according to any one of the foregoing implementations of the first aspect, and the motor is mounted on the vehicle frame. The motor enables that the vehicle keeps high efficiency in various running statuses, so that an endurance mileage of the vehicle can be effectively increased, and comprehensive running efficiency of the vehicle can be increased.

DESCRIPTION OF EMBODIMENTS

Embodiments of the present disclosure provide a rotor, a motor, a powertrain, and a vehicle. The rotor includes wedges and pole shoes. The wedges fit the pole shoes through curved portions. The curved portions can effectively relieve stress concentration of joint portions, increase strength of the wedges and the pole shoes, and effectively increase effective winding space of slots in the rotor. In this way, power density of a motor in which the rotor is used is increased.

The following describes Embodiments of the present disclosure with reference to accompanying drawings. A person of ordinary skill in the art may learn that, with technology development and emergence of a new scenario, the technical solutions provided in Embodiments of the present disclosure are also applicable to a similar technical problem.

In Embodiments of the present disclosure, “connection” is a physical connection, or a connection that can be made, or fitting, or contacting, or embedding, or clamping, or inosculating, or the like. The “connection” may alternatively be a location relationship between parts in a physical whole. This is not limited herein.

Electric excitation synchronous motors can be classified into a salient-pole motor and a hidden-pole motor, and an electric excitation synchronous motor used in a new energy vehicle usually uses a salient-pole rotor structure. A salient-pole rotor can accommodate more rotor windings, to increase torque density and power density of the motor. A pole shoe of the salient-pole rotor fits a wedge accommodated in a slot, to protect the windings and prevent the windings from flying and being damaged under action of centrifugal force when the rotor rotates at a high speed.

As requirements for power density of the motor become higher, requirements for the wedge and the pole shoe become higher. To increase power density of the motor, more windings need to be accommodated. Therefore, effective winding space of the slot needs to be as large as possible, and the wedge and the pole shoe need to be as small as possible. The wedge and the pole shoe need to ensure sufficient strength in a case of a smaller size. Therefore, how to design the rotor becomes an urgent technical problem to be resolved.

To resolve the foregoing technical problem, an embodiment of the present disclosure provides a rotor. A motor in which the rotor is used may be used in an electric vehicle (EV), a pure electric vehicle (PEV), a hybrid electric vehicle (HEV), a range extended electric vehicle (REEV), a plug-in hybrid electric vehicle (PHEV), a new energy vehicle, battery management, a motor driver, a power converter, or the like.

In this embodiment of the present disclosure, an example in which a motor is used in an electric vehicle is used for description.FIG.1is a schematic diagram of a structure of the electric vehicle. The electric vehicle100may include a vehicle frame40and a powertrain. The powertrain is mounted on the vehicle frame40. The vehicle frame40is used as a structural framework of the electric vehicle, and is configured to support, fasten, and connect various systems, and bear a load inside a vehicle system and a load from an external environment.

The powertrain is a system that includes a series of components and is configured to produce power and transmit the power to a road surface. Refer toFIG.1. The powertrain may include controllers20and motors10. The controller20is electrically connected to the motor10and is configured to control working of the motor10. The powertrain may further include reducers50. The reducer50is configured to be mechanically connected to the motor10, and is configured to reduce a rotation speed of the motor10and increase output torque of the motor10, to adjust a speed of the vehicle.

The electric vehicle100further includes wheels41disposed on the vehicle frame40. A rotating shaft of the powertrain is connected to the wheels41through transmission components. In this way, the rotating shaft of the powertrain outputs power, and the transmission components transmit the power to the wheels41, so that the wheels41rotate. In this embodiment of the present disclosure, the powertrain may include one, two, or more motors10. When there is one motor, the motor is connected to two front wheels or two rear wheels through transmission components. When there are two motors, one of the motors is connected to the two front wheels through transmission components, and the other motor is connected to the two rear wheels through other transmission components.

It should be noted that the electric vehicle100is merely used as an example for description, and the electric vehicle100may further include another component. This is not limited herein.

Further,FIG.2is a schematic diagram of a structure of a motor according to an embodiment of the present disclosure. A motor10includes a stator12and a rotor1000.FIG.3is a schematic diagram of a structure of a rotor according to an embodiment of the present disclosure. The rotor1000includes pole shoes1100, wedges1200, a rotor core1300, rotor windings1400, and a rotating shaft1500. As shown inFIG.3, the rotor core1300and the rotating shaft1500each may be cylindrical, and have an axial direction and a circumferential surface. The rotor core1300has an axial hole extending along the axial direction, and the rotor core1300is sleeved on the rotating shaft1500through the axial hole and is fastened to the rotating shaft1500, so that the rotating shaft1500rotates with the rotor core1300.

The stator12may have a cylindrical inner cavity. The stator12is sleeved on an outer circumference of the rotor core1300, and the rotor core1300is located in the inner cavity of the stator12. The stator12includes a stator core and stator windings disposed around the stator core. An air gap is between an outer circumferential surface of the rotor core1300and an inner cavity wall of the stator12. The rotating shaft1500penetrates out of the inner cavity of the stator12, so that the rotating shaft1500is connected to the reducer50to output torque.

The following describes in detail the rotor1000provided in this embodiment of the present disclosure. Refer toFIG.3. The rotor1000includes the rotor core1300, a plurality of wedges1200, a plurality of pole shoes1100, a plurality of rotor windings1400, and the rotating shaft1500. The rotor core1300is sleeved on the rotating shaft1500. The rotor windings1400are wound in each slot, and a plurality of slots are disposed at intervals along a circumferential direction of the rotor core1300. The rotor windings1400are wound in the slots of the rotor core1300, and the plurality of rotor windings1400are disposed at intervals along the circumferential direction of the rotor core1300. The rotor core1300includes a rotor core body and the plurality of pole shoes1100, and the plurality of pole shoes1100are disposed at intervals along a circumferential direction of the rotor core body. The wedge1200is disposed in a slot opening that is in the slot and that is away from the rotating shaft1500. The plurality of wedges1200are disposed at intervals along the circumferential direction of the rotor core body.

Further, the wedge1200is of a closed solid structure. The wedge1200may be made of an insulation material, for example, a polymer.

Further, the pole shoe1100may be made of a magnetic conductive material such as a silicon steel sheet.

FIG.4is a schematic diagram of a structure of a pole shoe according to an embodiment of the present disclosure. A pole shoe1100includes two symmetrical hook-shaped pole shoe end portions1110and a pole shoe body1120. The two hook-shaped pole shoe end portions1110are axisymmetrically disposed along the pole shoe body. The hook-shaped pole shoe end portion1110becomes thinner along a circumferential direction relative to the pole shoe body and includes at least one first curved portion1111. An area, facing an air gap, between the two hook-shaped pole shoe end portions1110is referred to as a second pole shoe portion1112.

Optionally, one or more concave curved portions, and/or one or more convex curved portions, and/or one or more line segments may be further included between the second pole shoe portion1112and the first curved portion1111. The second pole shoe portion1112is connected to the first curved portion1111through the foregoing structure.

As shown inFIG.8andFIG.9, the hook-shaped pole shoe end portion1110includes the first curved portion1111. The first curved portion1111includes one or more first concave curved portions11111, and/or one or more first convex curved portions11112, and/or one or more line segments.

FIG.5is a schematic diagram of a structure of a wedge according to an embodiment of the present disclosure. A first wedge portion1210fits first curved portions1111in hook-shaped pole shoe end portions1110of two adjacent pole shoes1100.

To implement fitting between the first wedge portion1210and the first curved portion1111, at least one second convex curved portion1211and/or at least one second concave curved portion1212that are/is included in the first wedge portion1210needs to be in pairs with at least one first convex curved portion11112and/or at least one first concave curved portion11111that are/is included in the first curved portion1111.

For example, “being in pairs” may be understood as “corresponding to”. If the first wedge portion1210includes one second convex curved portion1211, the first curved portion1111includes one first concave curved portion11111, the second convex curved portion1211of the first wedge portion1210and the first concave curved portion11111of the first curved portion1111are in a pair, and the second convex curved portion1211of the first wedge portion1210fits the first concave curved portion11111of the first curved portion1111.

If the first wedge portion1210includes one second concave curved portion1212, the first curved portion1111includes one first convex curved portion11112, the second concave curved portion1212of the first wedge portion1210and the first convex curved portion11112of the first curved portion1111are in a pair, and the second concave curved portion1212of the first wedge portion1210fits the first convex curved portion11112of the first curved portion1111.

It should be noted that a “curved portion” in this embodiment of the present disclosure may be alternatively replaced with a circular arc, a curve, a curved surface, a circular arc surface, an arc surface, or an arc. For example, a convex curved portion may also be referred to as a convex circular arc, a convex curved surface, or a convex arc surface. This is not limited herein.

One wedge1200includes one pair of first wedge portions1210. The pair of wedge portions1210are located on two sides of a wedge body1250and are symmetrical along a symmetry axis of the wedge1200. An area, facing an air gap, between the pair of first wedge portions1210is referred to as a second wedge portion1220.

FIG.6is a schematic diagram of a partial structure of a rotor according to an embodiment of the present disclosure. A wedge1200is connected to two adjacent pole shoes1100. The wedge1200includes first wedge portions1210, and the first wedge portion1210includes at least one curved portion. The first wedge portion1210may include one or more second concave curved portions1212, and/or one or more second convex curved portions1211, and/or one or more line segments.

Optionally, the wedge1200may further include a fourth wedge portion1240, and a radial bottom of the wedge body1250includes the fourth wedge portion1240. The rotor core1300further includes a first rotor core portion1310. The first rotor core portion1310radially faces toward the slot. A plurality of first rotor core portions1310are disposed at intervals along the circumferential direction of the rotor core body. The fourth wedge portion1240fits the first rotor core portion1310, to implement connection between the wedge1200and the rotor core1300. The fourth wedge portion1240includes one or more curved portions and/or one or more line segments. The first rotor core portion1310includes one or more curved portions and/or one or more line segments. The foregoing structures are used, to improve stability of the wedge1200in the slot. In addition, it is ensured that a length of the wedge body1250is long enough, so that the wedge1200is enough to fully isolate two rotor windings1400in the slot, and an insulation function is implemented.

For example, in addition to a V-shaped structure shown inFIG.6, the fourth wedge portion1240may be of another structure, for example, a W-shaped structure or a U-shaped structure. This is not limited herein.

Optionally, the slot is filled with potting compound1600. The potting compound1600is bonded to the wedge1200. The potting compound1600is bonded to the pole shoe1100. The potting compound1600is bonded to the rotor windings1400. The pole shoe1100, the wedge1200, and the rotor windings1400are solidified as a whole by using the potting compound, and strength of the components in the slot is increased.

In this embodiment of the present disclosure, the wedges fit the pole shoes through the curved portions. The curved portions can effectively relieve stress concentration of joint portions, increase strength of the wedges and the pole shoes, and effectively increase effective winding space of the slots in the rotor. In this way, strength of the wedges and the pole shoes is increased, a maximum speed of the motor can also be increased, and power density of the motor is increased.

Next, the pole shoe1100and the wedge1200in the rotor1000are separately described in detail.

First, the pole shoe1100is described.FIG.7is a schematic diagram of another structure of a pole shoe according to an embodiment of the present disclosure. The pole shoe1100includes the first curved portion1111, a second pole shoe portion1112, and a third pole shoe portion1113. The third pole shoe portion1113included in the hook-shaped pole shoe end portion1110includes one or more third concave curved portions and/or one or more line segments. The third pole shoe portion1113is tangent to the first curved portion1111. The third pole shoe portion1113is tangent to the second pole shoe portion1112. The third pole shoe portion1113is used to extend a circumferential length of the pole shoe. In this way, the pole shoe can accommodate more rotor windings1400, and torque density and power density of the motor in which the rotor1000is used are increased. As shown inFIG.7, the third pole shoe portion1113includes one third concave curved portion.

For the hook-shaped pole shoe end portion1110, there may be a plurality of implementation solutions. The following provides examples for description with reference to the accompanying drawings.

In a possible implementation solution, refer toFIG.8.FIG.8is a schematic diagram of a structure of a hook-shaped pole shoe end portion according to an embodiment of the present disclosure. The hook-shaped pole shoe end portion1110includes the first concave curved portion11111, a smooth transition arc1b, a convex curved portion1c, and a concave curved portion1d. The first concave curved portion11111fits the first wedge portion1210, and the concave curved portion1dis used to extend the circumferential length of the pole shoe1100. The first curved portion1111includes the first concave curved portion11111. The third pole shoe portion1113includes the concave curved portion1d.

Portions between the first concave curved portion11111and the concave curved portion1dinclude the smooth transition arc1band the convex curved portion1c. Structures of the smooth transition arc1band the convex curved portion1ccan reduce thickness of the pole shoe1100, reduce magnetic leakage, and weaken adverse impact caused by circumferential extension of the pole shoe1100.

In another possible implementation solution, refer toFIG.9.FIG.9is a schematic diagram of another structure of a hook-shaped pole shoe end portion according to an embodiment of the present disclosure. The hook-shaped pole shoe end portion1110includes the first convex curved portion11112, the first concave curved portion11111, a smooth transition arc2c, a line segment2d, a smooth transition arc2e, a line segment2f, a smooth transition arc2g, a line segment2h, and a concave curved portion2i. The first convex curved portion11112and the first concave curved portion11111fit the first wedge portion1210. In this case, the first wedge portion1210includes the second concave curved portion1212that is in pairs with (or that corresponds to) the first convex curved portion11112, and the second convex curved portion1211that is in pairs with (or that corresponds to) the first concave curved portion11111. The first curved portion1111includes the first concave curved portion11111and the first convex curved portion11112. The third pole shoe portion1113includes the concave curved portion2iand the line segment2h. The line segment2hand the concave curved portion2iare used to extend the circumferential length of the pole shoe1100.

Portions between the first concave curved portion11111and the line segment2hinclude the smooth transition arc2c, the line segment2d, the smooth transition arc2e, the line segment2f, and the smooth transition arc2g. Structures of the smooth transition arc2c, the line segment2d, the smooth transition arc2e, the line segment2f, and the smooth transition arc2gcan reduce thickness of the pole shoe1100, reduce magnetic leakage, and weaken adverse impact caused by circumferential extension of the pole shoe1100.

In another possible implementation solution, the first curved portion1111of the hook-shaped pole shoe end portion1110includes the first convex curved portion11112. In this case, the first wedge portion1210includes the second concave curved portion1212that is in pairs with (or corresponds to) the first convex curved portion11112.

It should be noted that the foregoing smooth transition arcs may include one or more arcs (or arc surfaces), or may include a combination of one or more arcs (arc surfaces) and line segments. This is not limited herein.

For the second pole shoe portion1112, there are also a plurality of possible implementations. The following describes the plurality of possible implementations with reference to the accompanying drawings.FIG.10is a schematic diagram of still another structure of a pole shoe according to an embodiment of the present disclosure. The second pole shoe portion1112is in an eccentric circular arc shape, and a center position of the eccentric circular arc shape does not coincide with an axis center of the rotating shaft.

In another possible implementation, the second pole shoe portion is in an arc shape of an air gap secant function. Specifically,FIG.11is a schematic diagram of yet another structure of a pole shoe according to an embodiment of the present disclosure. An air gap length of the second pole shoe portion1112satisfies: δ(θ)=δ0·sec θ, where δ(θ) represents the air gap length of the second pole shoe portion1112, δ0represents an air gap length at a position of a symmetry line of a pole arc curve in the pole shoe1100, and θ represents a circumferential angle between a radial line on which the second pole shoe portion1112is located and the symmetry line of the pole shoe1100. The air gap length is a length of a gap between the stator12and the rotor1000in the motor. The pole arc curve encloses a main area in which the pole shoe1100faces the air gap.

The foregoing pole shoe structure is used, so that torque fluctuation of the motor in which the pole shoe is used can be effectively reduced, and performance of noise, vibration, and harshness (NVH) of the motor can be improved.

Next, the wedge1200is described. There are also a plurality of implementation solutions for the wedge1200, for example, the structure shown inFIG.6, or a variation of the structure shown inFIG.6. For ease of understanding, refer toFIG.12.FIG.12is a schematic diagram of another structure of a wedge according to an embodiment of the present disclosure. The wedge1200includes the first wedge portions1210, the second wedge portion1220, the fourth wedge portion1240, and the wedge body1250.

One wedge1200includes one pair of first wedge portions1210. The pair of wedge portions1210are located on the two sides of the wedge body1250and are symmetrical along the symmetry axis of the wedge1200. The area, facing the air gap, between the pair of first wedge portions1210is referred to as the second wedge portion1220.FIG.12is used as an example. The first wedge portion1210includes one second convex curved portion1211.

It may be understood that the first wedge portion1210may further have another structure, to fit the first curved portion1111. For ease of understanding, refer toFIG.13.FIG.13is a schematic diagram of a structure of a first wedge portion according to an embodiment of the present disclosure. The first wedge portion1210includes one second convex curved portion1211and one second concave curved portion1212, and the first wedge portion1210fits the first curved portion1111through the second convex curved portion1211and the second concave curved portion1212. Specifically,FIG.14is a schematic diagram of fitting between the wedge1200and the pole shoe1100. Refer toFIG.14.FIG.14is a schematic diagram of another partial structure of a rotor according to an embodiment of the present disclosure. Stability of the wedge1200and the pole shoe1100is improved through the plurality of curved portions.

The wedge further includes the second wedge portion1220, the second wedge portion1220includes at least one concave curved portion, and two sides of the second wedge portion1220are connected to one pair of first wedge portions1210. The second wedge portion1220is in an arc surface shape, so that stress concentration in an area of an arc surface can be relieved, and strength of the wedge1200can be increased.

Optionally, the second wedge portion1220may further include one or more line segments. Alternatively, the second wedge portion1220may further include one or more convex curved portions, and/or one or more concave curved portions, and/or one or more line segments. For example, the second wedge portion1220includes one concave curved portion and two line segments tangent to the concave curved portion, and the concave curved portion is connected to the first wedge portions1210through the two line segments on the two sides.

Optionally, the wedge1200may further include one or more pairs of third wedge portions1230. The wedge1200shown inFIG.12includes one pair of third wedge portions1230. The wedge1200shown inFIG.6does not include the third wedge portion1230. Each pair of third wedge portions1230are located on the two sides of the wedge body1250, and are symmetrical along the symmetry axis of the wedge1200. The third wedge portion1230includes one or more circular arc curved portions and/or one or more line segments. The circular arc curved portion may be a convex curved portion, or may be a concave curved portion, or may be a combination of a convex curved portion and a concave curved portion. This is not limited herein.

For example, the wedge1200includes the plurality of pairs of third wedge portions1230. Refer toFIG.15.FIG.15is a schematic diagram of a structure of a third wedge portion according to an embodiment of the present disclosure. The wedge1200includes two pairs of third wedge portions1230.

Optionally, the pairs of third wedge portions1230are different in size and/or shape. For example, concave curved portions (or grooves) of one pair of third wedge portions are wide and shallow, and concave curved portions (or grooves) of the other pair of third wedge portions are narrow and deep. For another example, concave curved portions (or grooves) of one pair of third wedge portions are wide and deep, and concave curved portions (or grooves) of the other pair of third wedge portions are shallow and narrow. This is not limited herein.

Optionally, when the wedge1200includes the plurality of pairs of third wedge portions1230, the plurality of third wedge portions1230may be the same in size, and/or the plurality of third wedge portions1230may be the same in shape.

Bonding strength between the wedge and the potting compound is increased through the third wedge portion, and stability of the rotor is improved.

For descriptions of a direction or a position, refer to “a radial direction”, “an axial direction”, and “a circular direction”. In the meaning of this application, a rotation axis of the rotor1000is used.

It should be understood that “one embodiment” or “an embodiment” mentioned in the entire specification means that particular features, structures, or characteristics related to embodiments are included in at least one embodiment of the present disclosure. Therefore, “in one embodiment” or “in an embodiment” appearing throughout the specification does not refer to a same embodiment. In addition, these particular features, structures, or characteristics may be combined in one or more embodiments in any appropriate manner. It should be understood that sequence numbers of the foregoing processes do not mean execution sequences in various Embodiments of the present disclosure. The execution sequences of the processes should be determined according to functions and internal logic of the processes, and should not be construed as any limitation on the implementation processes of Embodiments of the present disclosure.

It should be understood that in Embodiments of the present disclosure, “B corresponding to A” indicates that B is associated with A, and B may be determined according to A. However, it should be further understood that determining B based on A does not mean that B is determined based only on A. B may alternatively be determined based on A and/or other information.

In conclusion, the foregoing is merely example embodiments of the technical solutions of this application, but are not intended to limit the protection scope of this application. Any modification, equivalent replacement, or improvement made without departing from the spirit and principle of this application shall fall within the protection scope of this application.