Stator assembly for electric motor, electric motor, electric drive assembly system and vehicle

Abstract

The present disclosure proposes a stator assembly (10) for an electric motor, comprising: a stator core (100), the stator core (100) being constructed as a hollow cylinder, multiple axially extending teeth (110) being provided on an inner peripheral wall of the stator core (100), and conductor slots (120) being formed between adjacent teeth (110); a winding, comprising a conductor (200) arranged in the conductor slot (120); an insulator (300), enclosing the conductor (200) in the conductor slot (120); an end insulating plate (400), provided with an end plate (410) extending radially along an outer end face (130) of an axial end of the stator core (100), and multiple sheathing slots (420) extending axially from the end plate (410), each sheathing slot (420) being inserted in the corresponding conductor slot (120), so that the conductor (200) extends through the corresponding sheathing slot (420).

Description

[0001] STATOR ASSEMBLY FOR ELECTRIC MOTOR, ELECTRIC MOTOR, ELECTRIC DRIVE ASSEMBLY SYSTEM AND VEHICLE

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to the field of electric motors, in particular to a stator assembly for an electric motor, and an electric motor comprising such a stator assembly.

[0004] BACKGROUND

[0005] A stator assembly for an electric motor comprises a stator core and conductors, the conductors being arranged in slots of the stator core and used to form windings. The conductors of the windings generally project at two axial ends of the stator core, for example to form a bun-like part of the windings. In the prior art, insulating paper is generally used to electrically insulate the stator core from the winding conductors. To ensure sufficient creepage distance between an axial end of the stator core and a winding conductor outside the axial end of the stator core, so as to avoid electrical conduction between the conductor and the stator core which would adversely affect electric motor performance, it is necessary to configure the insulating paper to extend beyond the corresponding axial end of the stator core by a sufficient length; this increases the length of the winding conductor that projects beyond the axial end of the stator core, and therefore increases the axial dimension of the stator assembly, inevitably making the overall size of an electric motor using such a stator assembly too big. This makes it difficult to integrate the electric motor in a confined space, and also detrimentally increases the material costs of winding wires and a motor housing, etc.

[0006] There is still a need for a stator assembly for an electric motor of a completely new design, to solve the abovementioned technical problems.

[0007] SUMMARY OF THE INVENTION

[0008] To this end, the present disclosure proposes a stator assembly for an electric motor; according to an embodiment, the stator assembly comprises: a stator core, the stator core being constructed as a hollow cylinder, multiple axially extending teeth being provided on a peripheral wall of the stator core, and conductor slots being formed between adjacent teeth; a winding, comprising a conductor arranged in the conductor slot; an insulator, enclosing the conductor in the conductor slot; an end insulating plate, provided with an end plate extending radially along an outer end face of an axial end of the stator core, and multiple sheathing slots extending axially from the end plate, each sheathing slot being inserted in the corresponding conductor slot, so that the conductor extends through the corresponding sheathing slot.

[0009] Thus, in the present disclosure, the axially extending sheathing slot of the end insulating plate that is inserted in the corresponding conductor slot lengthens an insulation creepage path around the corresponding winding conductor by extending axially inwards from the axial end of the stator core; more specifically, it lengthens an insulation creepage path between the stator core and the winding conductor located at the axial end of the stator core, such that there is no need to use insulating paper around the winding conductor projecting beyond the axial end of the stator core, so the length of the winding conductor that projects beyond the axial end of the stator core will not be increased, and therefore, the axial dimension of the stator assembly will not be increased, and material for the winding conductor can be saved, increasing cost-effectiveness. If the stator assembly is used in an electric motor, this also helps to form an electric motor with a more compact structure overall, facilitating integration of the electric motor in a confined space, while also enabling a reduction in the use of materials for the electric motor housing, etc., thereby lowering costs. In addition, the end plate of the end insulating plate that extends radially along the outer end face of the axial end of the stator core gives rise to a circumferential insulation creepage path between circumferentially adjacent sheathing slots; that is, it gives rise to an insulation creepage distance in the circumferential direction between adjacent winding conductors that project beyond the axial end of the stator core, thus ensuring electrical insulation between the winding conductors. According to various embodiments of the present disclosure, the stator assembly proposed in the present disclosure may comprise one or more of the following developments.

[0010] In some embodiments, each of the sheathing slots is located, in the corresponding conductor slot, between the corresponding insulator and the stator core. This further ensures electrical insulation between the stator core and the winding conductor.

[0011] In some embodiments, the end insulating plate is annular, and the end insulating plate is provided with a flange at a radially inner side, the flange extending from the end plate. The flange can further lengthen the insulation creepage path between the stator core and the winding conductor located at the axial end of the stator core.

[0012] In some embodiments, the flange extends axially in the opposite direction to a direction of extension of the sheathing slot. Due to the sheathing slots, the flange does not need to extend too much axially. More specifically, the flange does not need to extend axially outwards in such a way that the length of the winding conductor that projects beyond the axial end of the stator core needs to be increased.

[0013] In some embodiments, the end insulating plate further comprises multiple dividing ribs extending outwards from the end plate, each dividing rib being arranged at a joining part between two adjacent sheathing slots. This dividing rib can further lengthen the insulation creepage distance between adjacent winding conductors that project beyond the axial end of the stator core.

[0014] In some embodiments, the dividing rib extends axially in the opposite direction to a direction of extension of the sheathing slot. More specifically, the dividing rib does not need to extend axially outwards in such a way that the length of the winding conductor that projects beyond the axial end of the stator core needs to be increased.

[0015] In some embodiments, the end insulating plate is a single member made of plastic. Thus, the end insulating plate may be made in a way which reduces the number of process steps and saves materials, and which therefore reduces costs; moreover, the end insulating plate being in the form of a single member reduces the number of assembly steps, further aiding cost-effectiveness.

[0016] In some embodiments, the sheathing slot of the end insulating plate is elastically deformable. This facilitates proper installation of the sheathing slots of the end insulating plate in the conductor slots of the stator core, and retention of the end insulating plate on the stator core.

[0017] In some embodiments, the end plate of the end insulating plate covers at least a portion of, or all of, the outer end face of the axial end of the stator core.

[0018] In some embodiments, one said end insulating plate is provided at each axial end of the stator core.

[0019] In some embodiments, a slot cross section of a portion of the conductor slot that receives the corresponding sheathing slot is larger than a slot cross section of a remaining part of the conductor slot. This facilitates proper installation of the sheathing slot of the end insulating plate in the corresponding conductor slot, while the slot fill factor of the conductor slot can still be guaranteed, so that the performance of the stator assembly will not be adversely affected in any way by the end insulating plate.

[0020] According to another aspect of the present disclosure, the present disclosure also proposes an electric motor, comprising the stator assembly according to any one of the embodiments above. Because of this, the electric motor proposed in the present disclosure has the abovementioned advantages described in relation to the stator assembly.

[0021] According to another aspect of the present disclosure, the present disclosure also proposes an electric drive assembly system, comprising the stator assembly or electric motor mentioned above.

[0022] According to another aspect of the present disclosure, the present disclosure also proposes a vehicle, comprising the stator assembly, electric motor or electric drive assembly system mentioned above.

[0023] BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to describe more clearly the technical solutions of embodiments of the present disclosure, the drawings required by the embodiments will be briefly described below. It should be understood that the following drawings show only some embodiments of the present disclosure, and so should not be regarded as limiting the scope; those of ordinary skill in the art, without inventive effort, could further obtain other relevant drawings on the basis of these drawings. In the drawings:

[0025] Fig. 1 is a 3D schematic drawing of a stator assembly according to an exemplary embodiment, with most of the winding wires removed.

[0026] Fig. 2 is a 3D schematic drawing of an end insulating plate of a stator assembly according to an exemplary embodiment.

[0027] Fig. 3 is a 3D schematic drawing of the end insulating plate in Fig. 2, shown from another angle.

[0028] Fig. 4 is a 3D schematic drawing of the stator assembly shown in Fig. 1, shown from another angle.

[0029] Fig. 5 is a partial longitudinal sectional view of a stator assembly according to an exemplary embodiment.

[0030] Fig. 6 is a partial longitudinal sectional view of a stator assembly according to an exemplary embodiment, shown from another angle.

[0031] Fig. 7 is a partial enlarged sectional drawing showing the extension lengths of a sheathing slot, a flange and a dividing rib of an end insulating plate according to an exemplary embodiment.

[0032] DETAILED DESCRIPTION

[0033] A stator assembly according to embodiments of the present disclosure is described in detail below with reference to the drawings. To clarify the objective, technical solution and advantages of this practical disclosure, the technical solutions in embodiments of the present disclosure are described clearly and completely below in conjunction with the drawings in embodiments of the present disclosure; obviously, the embodiments described are some, not all, of the embodiments of the present disclosure.

[0034] Thus, the detailed description below of embodiments of the present disclosure provided in conjunction with the drawings is not intended to limit the claimed scope of the present disclosure, and merely shows selected embodiments of the present disclosure. All other embodiments obtained by those skilled in the art on the basis of the embodiments in the present disclosure without inventive effort are included in the scope of protection of the present disclosure.

[0035] Unless otherwise defined in the context, the singular includes the plural. Throughout this specification, the terms "comprising", "having", etc. are used herein to specify the existence of the mentioned characteristic, number, step, operation, element, component or combination thereof, without ruling out the existence or addition of one or more other characteristics, numbers, steps, operations, elements, components or combinations thereof.

[0036] In addition, although terms including ordinal numbers such as "first", "second", etc. may be used to describe various components, these components are not limited by these terms, which are merely used to differentiate one element from another. For example, without departing from the scope of the present disclosure, a first component may be referred to as a second component and, similarly, a second component may be referred to as a first component.

[0037] In the description of the present invention, it must be understood that orientational or positional relationships indicated by the terms "upper", "lower", "left," "right," "inner," "outer," etc. are based on the orientational or positional relationships shown in the drawings, or are the orientational or positional relationships in which the disclosed product is usually placed when used, or are the orientational or positional relationships commonly understood by those skilled in the art, and are merely intended to facilitate and simplify description of the present disclosure, rather than indicating or implying that the device or element in question must have a specific orientation or be constructed and operated in a specific orientation, and thus should not be construed as limiting the present disclosure.

[0038] As shown in Figs. 1 - 6, a stator assembly 10 for an electric motor is proposed in accordance with one aspect of the present disclosure. According to an embodiment, the stator assembly 10 comprises a stator core 100, windings, insulators 300 and an end insulating plate 400.

[0039] In an embodiment as shown in Figs. 1 and 4 - 6, the stator core 100 is constructed as a hollow cylinder, with multiple axially extending teeth 110 provided on a peripheral wall of the stator core 100; more specifically, the teeth 110 open on an inner peripheral wall, and conductor slots 120 are formed between adjacent teeth 110. For example, a hollow part 170 of the stator core 100 can accommodate a rotor (not shown) for forming the electric motor. The windings may comprise conductors 200 arranged in the conductor slots 120. In some embodiments, the stator core 100 of the stator assembly 10 may be formed of stacked thin metal plates, and the inner peripheral wall of the stator core 100 may be provided with slots 120 which open inwards; these slots 120 are defined by the stator teeth 110 in the circumferential direction, the slots 120 being used to receive windings that form different phase windings. The windings run through the slots 120 in the axial direction and form bun parts that protrude at each axial end 150, 160 of the stator core 100. The windings are for example obtained from continuous wires covered with enamel, or conductive elements in the form of pins connected to each other by welding, wound around the corresponding teeth 110. These windings form multiple phase windings, connected in star or delta form for example, with outputs connected to an inverter (not shown), which may also be used as a rectifying bridge.

[0040] It should be noted that in the sense of this text, "axial direction" is a direction along a central longitudinal axis X (shown schematically with a dotted line in Fig. 1) of the stator assembly 10, and more specifically may be along a rotation axis of a rotor shaft of the electric motor comprising the stator assembly 10; "circumferential direction" is a direction encircling the axial direction, more specifically a direction encircling the central longitudinal axis X of the stator assembly 10; and "radial direction" is a direction perpendicular to the central longitudinal axis X of the stator assembly 10, more specifically a direction of extension from the central longitudinal axis X of the stator assembly 10 towards the outside of the stator assembly 10 in a direction perpendicular to the central longitudinal axis X.

[0041] In some embodiments, as shown in Figs. 5 - 6, the insulators 300 enclose the winding conductors 200 in the corresponding conductor slots 120, to ensure electrical insulation between the stator core 100 and the conductors 200. More specifically, the insulators 300 are insulating paper. For example, the insulating paper may be folded to match the inner peripheral shape of the conductor slots 120, so as to be able to be laid in the conductor slots 120 in a shape-fitted manner.

[0042] In some embodiments, as shown in Figs. 2 - 6, the end insulating plate 400 may be provided with an end plate 410 extending radially along an outer end face 130 of the axial end 150 of the stator core 100, and multiple sheathing slots 420 extending axially from the end plate 410, each sheathing slot 420 being inserted in the corresponding conductor slot 120, so that the conductor 200 received in the corresponding conductor slot 120 can simultaneously extend through the corresponding sheathing slot 420 to a position outside the axial end 150 of the stator core 100, so as to form a bun part for example. In some embodiments, the end plate 410 of the end insulating plate 400 covers at least a portion of the outer end face 130 of the corresponding axial end 150 of the stator core 100. In other embodiments, the end plate 410 of the end insulating plate 400 covers all of the outer end face 130 of the corresponding axial end 150 of the stator core 100. More specifically, the end plate 410 of the end insulating plate 400 is arranged in abutment with the outer end face 130 of the corresponding axial end 150 of the stator core 100. More specifically, the sheathing slot 420 may be arranged in abutment with an inner wall of the corresponding conductor slot 120.

[0043] Thus, in the present disclosure, the axially extending sheathing slot 420 of the end insulating plate 400 that is inserted in the corresponding conductor slot 120 of the stator core 100 lengthens the insulation creepage path around the corresponding winding conductor 200 by extending axially inwards from the axial end 150, 160 of the stator core 100; more specifically, it lengthens the insulation creepage path between the stator core 100 and the winding conductor 200 located at the axial end 150, 160 of the stator core 100, such that there is no need to use insulating paper around the winding conductor 200 projecting beyond the axial end 150, 160 of the stator core 100, so the length of the winding conductor 200 that projects beyond the axial end 150, 160 of the stator core 100 will not be increased, and therefore, the axial dimension of the stator assembly 10 will not be increased, and material for the winding conductor 200 can be saved, increasing cost-effectiveness. If the stator assembly 10 is used in an electric motor, this also helps to form an electric motor with a more compact structure overall, facilitating integration of the electric motor in a confined space, while also enabling a reduction in the use of materials for the electric motor housing, etc., thereby lowering costs. In addition, the end plate 410 of the end insulating plate 400 that extends radially along the outer end face 130 of the axial end 150, 160 of the stator core 100 gives rise to a circumferential insulation creepage path between circumferentially adjacent sheathing slots 420; that is, it gives rise to an insulation creepage distance in the circumferential direction between adjacent winding conductors 200 that project beyond the axial end 150, 160 of the stator core 100, thus ensuring electrical insulation between the winding conductors 200.

[0044] More specifically, the end insulating plate 400 of the present disclosure may be provided at one or both of the two axial ends 150, 160 of the stator core 100.

[0045] In some embodiments, as shown in Figs. 5 - 6, the sheathing slot 420 of the end insulating plate 400 may be configured to be located between the corresponding insulator 300 and the stator core 100. This further ensures electrical insulation between the stator core 100 and the winding conductor 200. In a more specific embodiment, a slot cross section of a portion of the conductor slot 120 of the stator core 100 that receives the corresponding sheathing slot 420 may be configured to be larger than a slot cross section of a remaining part of the conductor slot 120. This facilitates proper installation of the sheathing slot 420 of the end insulating plate 400 in the corresponding conductor slot 120, while the slot fill factor of the conductor slot 120 can still be guaranteed, so that the performance of the stator assembly 10 will not be adversely affected in any way by the end insulating plate 400. More specifically, if the stator core 100 of the stator assembly 10 is provided with end insulating plates 400 at both axial ends 150, 160, the conductor slot 120 of the stator core 100 is formed to have a larger slot cross section near the two axial ends than in an axially middle portion, the end portions of larger slot cross section being used to receive the sheathing slots 420 and optionally the insulator 300. In some embodiments, the end insulating plate 400 may be configured so that the sheathing slots 420 thereof are elastically deformable. This facilitates proper installation of the sheathing slots 420 of the end insulating plate 400 in the conductor slots 120 of the stator core 100, and retention of the end insulating plate 400 on the stator core 100.

[0046] In some embodiments, as shown in Figs. 2 - 4, the end insulating plate 400 is configured to be annular overall. For example, the end insulating plate 400 may be provided with a central hole 470 aligned with the hollow part 170 of the stator core 100, to allow a rotor received in the hollow part 170 of the stator core 100 to project, for example. In some embodiments, as shown in Figs. 2 - 6, the end insulating plate 400 is provided with a flange 430 at a radially inner side, the flange extending from the end plate 410 thereof. The flange 430 can further lengthen the insulation creepage path between the stator core 100 and the winding conductor 200 located at the axial end 150, 160 of the stator core 100. In an embodiment which is not shown, the flange 430 may extend radially from the radially inner side of the end insulating plate 400, e.g. the side that defines the central hole 440 thereof. In another specific embodiment, as shown in the figures, the flange 430 may extend axially in the opposite direction to the direction of extension of the sheathing slots 420. Due to the sheathing slots 420, the flange 430 can achieve a sufficiently long insulation creepage path without needing to extend too much axially. More specifically, the flange 430 does not need to extend axially outwards in such a way that the length of the winding conductor 200 that projects beyond the axial end 150, 160 of the stator core 100 needs to be increased. It should be understood that the flange 430 could also extend in another direction, as long as it can increase the insulation creepage path and will not increase the axial projection length of the conductor 200.

[0047] In a specific embodiment, as shown in Fig. 7, an axial extension length of the sheathing slot is referred to as a first extension length a, and the first extension length a should be no less than a minimum permitted creepage distance between the stator core 100 and the winding conductor 200 located at the axial end 150, 160 of the stator core 100; that is, if it were less than the minimum permitted creepage distance, there would be a risk of current creeping to the stator core 100 from the winding conductor 200 located at the axial end 150, 160 of the stator core 100. An extension length of the flange 430 of the end insulating plate 400, more specifically the length of straight extension from a part connected to the end plate 410 of the end insulating plate 400 to a free edge of the flange 430, is referred to as a second extension length b, which is less than the first extension length a, and more specifically set as b = a / 2.

[0048] In some embodiments, as shown in Figs. 3 - 6, the end insulating plate 400 may further comprise multiple dividing ribs 440 extending outwards from the end plate 410 thereof, each dividing rib 440 being arranged at a joining part between two adjacent sheathing slots 420. This dividing rib 440 can further lengthen the insulation creepage path between adjacent winding conductors 200 that project beyond the axial end 150, 160 of the stator core 100. In some embodiments, as shown in the figures, the dividing ribs 440 extend axially in the opposite direction to the direction of extension of the sheathing slots 420. More specifically, the dividing rib 440 can achieve a sufficiently long insulation creepage path without needing to extend axially outwards in such a way that the length of the winding conductor 200 that projects beyond the axial end 150, 160 of the stator core 100 needs to be increased. In some embodiments, as shown in the figures, the dividing rib 440 is configured to extend radially outwards from the flange 430 of the end insulating plate 400 beyond the limit of radial extension of the sheathing slots 420 adjacent thereto. More specifically, in an embodiment which is not shown, the dividing rib 440 may have a triangular or trapezoidal radial cross section, i.e. it comprises sloping faces to further lengthen the creepage path. It should be understood that the dividing rib 440 could extend in another direction, as long as it can increase the insulation creepage path and will not increase the axial projection length of the conductor 200. In a specific embodiment, as shown in Fig. 7, an extension length of the dividing rib 440 from a part thereof connected to the end plate 410 to a free edge thereof, referred to as a third extension length c, is less than the first extension length a, its specific value depending on a creepage distance between circumferentially adjacent winding conductors 200 that project beyond the axial ends 150, 160 of the stator core 100.

[0049] In some embodiments, as shown in Figs. 2 - 4, the end insulating plate 400 is a single member, i.e. a one-piece member. More specifically, the end insulating plate 400 is made of plastic. Thus, the end insulating plate 400 may be made in a way which reduces the number of process steps and saves materials, and which therefore reduces costs; moreover, the end insulating plate 400 being in the form of a single member reduces the number of assembly steps, further aiding costeffectiveness.

[0050] According to another aspect of the present invention, the present disclosure also proposes an electric motor, comprising the stator assembly 10 according to any one of the embodiments above. Because of this, the electric motor proposed in the present disclosure has the abovementioned advantages described in relation to the stator assembly 10.

[0051] According to another aspect of the present disclosure, the present disclosure also proposes an electric drive assembly system, comprising the stator assembly or electric motor mentioned above.

[0052] According to another aspect of the present disclosure, the present disclosure also proposes a vehicle, comprising the stator assembly, electric motor or electric drive assembly system mentioned above, and having the functions mentioned above. The vehicle may be an electrified vehicle, for example, a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), a range-extended EV, or a fuel cell electric vehicle (FCEV). The vehicle may also be a hydrogen-powered vehicle.

[0053] While demonstrative embodiments of the stator assembly proposed in the present invention have been described in detail above with reference to preferred embodiments, those skilled in the art will understand that various modifications and changes could be made to the specific embodiments above without departing from the concept of the present invention, and various technical features and structures proposed in the present invention could be combined in various ways without exceeding the scope of protection of the present invention.

[0054] The scope of the present disclosure is not defined by the embodiments described above, but by the appended claims and their equivalent scope.

Claims

WHAT IS CLAIMED IS:L A stator assembly (10) for an electric motor, comprising: a stator core (100), constructed as a hollow cylinder, and multiple axially extending teeth (110) being provided on a peripheral wall of the stator core (100), and a conductor slot (120) being formed between adjacent teeth (110); a winding, comprising a conductor (200) arranged in the conductor slot (120); an insulator (300), enclosing the conductor (200) in the conductor slot (120); an end insulating plate (400), provided with an end plate (410) extending radially along an outer end face (130) of an axial end of the stator core (100), and multiple sheathing slots (420) extending axially from the end plate (410), each sheathing slot (420) being inserted in the corresponding conductor slot (120), so that the conductor (200) extends through the corresponding sheathing slot (420).

2. The stator assembly (10) according to Claim 1, wherein each of the sheathing slots (420) is located, in the corresponding conductor slot (120), between the corresponding insulator (300) and the stator core (100).

3. The stator assembly (10) according to Claim 1 or 2, wherein the end insulating plate (400) is annular, and the end insulating plate (400) is provided with a flange (430) at a radially inner side, and the flange extends from the end plate (410).

4. The stator assembly (10) according to Claim 3, wherein the flange (430) extends axially in the opposite direction to a direction of extension of the sheathing slot (420).

5. The stator assembly (10) according to Claim 1 or 2, wherein the end insulating plate (400) further comprises multiple dividing ribs (440) extending outwards from the end plate (410), and each dividing rib (440) being arranged at a joining part between two adjacent sheathing slots (420).

6. The stator assembly (10) according to Claim 5, wherein the dividing rib (440) extends axially in the opposite direction to a direction of extension of the sheathing slot (420).

7. The stator assembly (10) according to Claim 1 or 2, wherein the endinsulating plate (400) is a single member made of plastic.

8. The stator assembly (10) according to Claim 1 or 2, wherein the sheathing slot (420) of the end insulating plate (400) is elastically deformable.

9. The stator assembly (10) according to Claim 1 or 2, wherein the end plate (410) of the end insulating plate (400) covers at least a portion of, or all of, the outer end face (130) of the axial end of the stator core (100).

10. The stator assembly (10) according to Claim 1 or 2, wherein one said end insulating plate (400) is provided at each axial end of the stator core (100).

11. The stator assembly (10) according to Claim 1 or 2, wherein a slot cross section of a portion of the conductor slot that receives the corresponding sheathing slot is larger than a slot cross section of a remaining part of the conductor slot.

12. An electric motor, comprising the stator assembly (10) according to any one of Claims 1 to 11.

13. An electric drive assembly system, comprising the stator assembly (10) according to any one of Claims 1 to 11 or the electric motor according to Claim 12.

14. A vehicle, comprising the stator assembly (10) according to any one of Claims 1 to 11 or the electric motor according to Claim 12 or the electric drive assembly system according to Claim 13.

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