Method for manufacturing a rotor device, corresponding rotor device for an electric machine and vehicle

Abstract

Method (1) for manufacturing a rotor device (10) for an electric machine (100), the method (1) comprising steps (S1-S4) of: – Providing a salient-pole rotor (11) having a plurality of poles (19), each pole (19) being formed by a coil (13) wound around a pole section (17) of a rotor core (12) of the rotor (11), between each circumferentially adjacent pair of poles (19), an accommodation space (20) being formed between the coils (13) of the pair of poles (19); – Providing elastically deformable bodies (21); – Arranging the bodies (21) into the accommodation spaces (20) such that a respective one of the bodies (21) occupies a first volume of a respective one of the accommodation spaces (20); and – Elastically deforming the respective body (21) such that it occupies a second volume of the accommodation space (20) being larger than the first volume and such that the body (20) supports the coils (13) of the pair of poles (19), between which the body (21) is arranged.

Description

[0001] Method for manufacturing a rotor device, corresponding rotor device for an electric machine and vehicle

[0002] The present invention relates to a method for manufacturing a rotor device for an electric machine. Aside, the invention relates to a rotor device for an electric machine, to an electric machine for a vehicle and to a vehicle.

[0003] In salient-pole rotors with a coil wound around pole sections of a rotor core, it is generally known to dispose supporting bodies between the pole sections so as to support the coils. Such bodies are also known as support elements, wedges or so called lockledges.

[0004] Exemplarily, US 2020 / 0177046 A1 discloses a rotor for an electrical machine. The rotor comprises a rotor stack having a plurality of pole teeth and windings around the pole teeth. A support element is arranged in the grooves between the windings.

[0005] In conventional rotors devices, such bodies have to be manufactured very precisely in order to ensure that they sufficiently fit with the coils. Correspondingly, the coils have to positioned very precisely so as to be supported by the body. Failing to adjust the dimensions of the body and the coils accurately may cause a damage of the insulation of the coil during assembly of the rotor. Accordingly, the manufacturing process for such rotor devices is difficult and costly.

[0006] It is an object of the present invention to provide a possibility for an improved support of coils in a rotor device with a salient-pole rotor.

[0007] According to the invention, this object is solved by a method for manufacturing a rotor device for an electric machine, the method comprising steps of: providing a salient-pole rotor having a plurality of poles, each pole being formed by a coil wound around a pole section of a rotor core of the rotor, between each circumferentially adjacent pair of poles, an accommodation space being formed between the coils of the pair of poles; providing elastically deformable bodies; arranging the bodies into the accommodation spaces such that a respective one of body occupies a first volume of a respective one of the accommodation spaces; and elastically deforming the respective body such that it occupies a second volume of the accommodation space being larger than the first volume and such that the body supports the coils of the pair of poles, between which the body is arranged.

[0008] The method according to the invention comprises a step of providing a salient-pole rotor. The rotor has a plurality of poles. Each pole is formed by a coil wound around a pole section of a rotor core of the rotor. Between each circumferentially adjacent pair of poles, an accommodation space is formed between the coils of the pair of poles.

[0009] The method according to the invention comprises a further step of providing bodies. The bodies are elastically deformable.

[0010] The method according to the invention comprises a further step of arranging the bodies into the accommodation spaces such that a respective one of body occupies a first volume of a respective one of the accommodation spaces.

[0011] The method according to the invention comprises a further step of elastically deforming the respective body such that it occupies a second volume of the accommodation space and such that the body supports the coils of the pair of poles, between which the body is arranged. The second volume is larger than the first volume.

[0012] The invention is based upon the consideration to arrange the elastically deformable body between the coil and to deform, in particular to expand, the body so that it occupies the larger second volume and supports the coils, therein adapting the body by the process of deforming to the dimensions of the coils. This allows to manufacture and wind the coils with higher tolerances and lower winding accuracy, therein reducing the manufactural effort, the likelihood for a violation of quality demands and increasing the winding speed.

[0013] The rotor core may comprise a plurality of axially stacked rotor sheets. The rotor core may comprise an annular central section. The central section may comprise a central opening for shaft to be attached to the rotor. The pole section may extend in a radial direction away from the central section. At a radially distal end of a respective pole section, the pole section may be provided with a pole shoe. The pole shoe may delimit the radial extent of the coil wound around the pole section.

[0014] The coil may be made of an electrically insulated wire, wound in multiple layers around the pole section. In a preferred embodiment, the circumferential extent of the coil may increase in the radially outward direction.

[0015] The body may be made of a polymer. Preferably, the body is sufficiently soft and elastic.

[0016] According to a first preferred variant of the method according to the invention, the body may be an elastically deformable container for a fluid. In general, the fluid may be a liquid or may be gaseous.

[0017] Therein, the container may be elastically deformed by pumping the fluid into the container, therein expanding the container inside the accommodation space. That is, by pumping the fluid into the body or the container, respectively, the body expands until it occupies the second volume and supports the pair of coils. In this case, the container may be of a balloon-type with an opening for filling the fluid into the container.

[0018] According to a preferred first specific implementation, the fluid comprises a resin.

[0019] Therein, the method may comprise a further step of: Curing the resin in a state of the container, in which it occupies a (third) volume being larger than the first volume. That is, the step of curing involves a waiting time until the resin is sufficiently cured. It should be noted that the third volume, which refers to the cured state of the resin, may be slightly smaller than the second volume, which is achieved immediately after having filled the resin into the container, due to shrinkage effects.

[0020] According to a preferred second specific implementation, the fluid is gaseous. Therein, the method may comprise a further step of: Closing the container in a gastight manner in a state, in which it occupies a (third) volume being larger than the first volume. Again, it should be noted that the third volume may be slightly smaller than the second volume due to leakage effects.

[0021] With regard to the first preferred variant, it is also possible that the container is provided as a bag being filled with a first component chosen from a group of a resin and a hardener and at least one closed subcontainer filled with a second component being the other member of the group. Therein, the bag may be elastically deformed by applying an outer pressure to the bag causing the subcontainers to rupture and creating a mixture of the first and second component. The method may comprise a further step of: Curing the mixture in a state of the bag, in which it occupies a volume being larger than the first volume. Typically, the bag is provided in a closed state.

[0022] According to a second preferred variant of the method according to the invention, the body may comprise an axial opening for a shaft with a longitudinal axis. The body may be a solid body, which forms the opening therein. Exemplarily, the body may be made of rubber. Preferably, the rod is made of less elastically deformable material than the body, e.g. made from metal or a hard polymer.

[0023] The body may be provided with the rod being accommodated in the opening. That is, the body is already disposed inside the opening during the step of providing the elastically deformable body. Alternatively or additionally, the body is elastically deformed by inserting the rod into the opening. That is inserting the rod is included in the step of elastically deforming the body.

[0024] Preferably, the rod has an excentric cross-section, wherein the body is elastically deformed by rotating the rod about its longitudinal axis. The longitudinal axis of the rod may be aligned in parallel with a longitudinal axis of the rotor. The cross-section of the rod may be e.g. oblong, oval or rectangular.

[0025] The method may comprise a further step of fastening the rod in its rotated position. Therein, the rod can be fixed to an end plate provided to the rotor.

[0026] With regard to the second preferred variant, the body may be provided with multiple openings and a corresponding number rods may be provided.

[0027] According to the invention, the above object is further solved by a rotor device for an electric machine, the rotor device comprising: a salient-pole rotor having a plurality of poles, each pole being formed by a coil wound around a pole section of a rotor core of the rotor, between each circumferentially adjacent pair of poles, an accommodation space being formed between the coils of the pair of poles; elastically deformed bodies arranged inside a respective accommodation space such that a respective one of the bodies supports the coils of the pair of poles, between which the body is arranged.

[0028] The rotor device according to the invention comprises a salient-pole rotor. The rotor has a plurality of poles. Each pole is formed by a coil wound around a pole section of a rotor core of the rotor. Between each circumferentially adjacent pair of poles, an accommodation space is formed between the coils of the pair of poles.

[0029] The rotor device according to the invention further comprises elastically deformed bodies. The bodies are arranged inside a respective accommodation space such that a respective one of the bodies supports the coils of the pair of poles, between which the body is arranged.

[0030] The body may be a container filled with a gaseous fluid, the container being closed in a gas tight manner. Alternatively, the container may be filled with a cured resin. Alternatively, the container may be filled with a cured mixture of a resin and a hardener and ruptured subcontainers.

[0031] The body may comprise an axial opening and a rod with a longitudinal axis accommodated inside the opening, wherein the body is elastically deformed by the rod.

[0032] Therein, the rod may have an excentric cross-section and is configured such that the body occupies a smaller volume of the accommodation space when rotating the rod about its longitudinal axis.

[0033] According to the invention, the above object is further solved by an electric machine for a vehicle, the electric machine comprising: a stator; a rotor device as described afore or a rotor device obtained by a method as described afore; the rotor device being mounted rotatably relative the stator.

[0034] According to the invention, the above object is further solved by a vehicle, comprising an electric machine according to the invention, wherein the electric machine is configured to propel the vehicle.

[0035] All statements referring to the manufacturing method according to the invention apply analogously to the rotor device according to the invention, the electric machine according to the invention and to the vehicle according to the invention, so that the above-mentioned advantages of the method may be achieved as well.

[0036] Further details and advantages of the invention are disclosed in the following embodiments, wherein reference is made to the drawings. The drawing show schematically: Fig. 1 a flow diagram of embodiments of the manufacturing method according to the invention;

[0037] Fig. 2 a perspective view of salient-pole rotor;

[0038] Fig. 3 a cross-sectional view of the rotor shown in Fig. 2;

[0039] Fig. 4 a detailed cross-sectional view of the rotor shown in Fig. 2 having the body arranged in one of the accommodation spaces according to the first embodiment of the method;

[0040] Fig. 5 a detailed cross-sectional view of a first embodiment of the rotor device according to the invention;

[0041] Fig. 6 a detailed cross-sectional view of the rotor shown in Fig. 2 having the body arranged in one of the accommodation spaces according to the third embodiment of the method;

[0042] Fig. 7 a detailed cross-sectional view of a third embodiment of the rotor device according to the invention;

[0043] Fig. 8 a detailed cross-sectional view of the rotor shown in Fig. 2 having the body arranged in one of the accommodation spaces according to the fourth embodiment of the method;

[0044] Fig. 9 a detailed cross-sectional view of a fourth embodiment of the rotor device according to the invention; and

[0045] Fig. 10 a principle drawing of an embodiment the electric machine according to the invention in an embodiment of the vehicle according to the invention. Fig. 1 is a flow diagram of embodiments of a method 1 for manufacturing a rotor device 10.

[0046] According to a first embodiment, the method 1 comprises a step S1 of providing a salient-pole rotor 11 .

[0047] Fig. 2 and Fig. 3 show the rotor 11 , wherein Fig. 2 is a perspective view and Fig. 3 is a cross-sectional view.

[0048] The rotor 11 comprises a rotor core 12 and coils 13. The rotor core 12 is made of a plurality of axially stacked rotor sheets 14. The rotor core 12 comprises an annular central section 15, which comprises a central opening 16 for a rotor shaft to be attached to the rotor 11 , and pole sections 17, which extend in a radial direction away from the central section 15. At a radially distal end of a respective pole section 17, the pole section is provided with a pole shoe 18.

[0049] The number of coils 13 corresponds to the number of pole sections 17 of the rotor core 12. Therein, each coil 13 is wound around one of the pole sections 17, therein forming a pole 19 of the rotor 11 . Between each circumferentially adjacent pair of poles 19, an accommodation space 20 is formed between the coils 13 of the pair of poles 19. In the radial direction, the coil 13 is delimited by the pole shoe 18.

[0050] In particular detail, each coil 13 is made of an electrically insulated wire, wound in multiple layers around the pole section 17. The circumferential extent of the coil 13 increases in the radially outward direction until the coil reaches a predefined radial position. That is, between the central section 15 and the predefined radial position, the accommodation space 20 has a substantially rectangular cross-section.

[0051] Fig. 4 is a detailed cross-sectional view of the rotor 11 shown in Fig. 2 having a body 21 arranged in one of the accommodation spaces 20. The method 1 comprises a further step S2 of providing elastically deformable bodies 21 . The number of bodies corresponds to the number of accommodation spaces 20 or poles 19, respectively. In the present embodiment, the body 21 is an elastically deformable container for a fluid (see Fig. 5). In particular, the container is of a balloon-type with an opening 22.

[0052] The method 1 comprises a further step S3 of arranging the bodies into the accommodation spaces such that a respective one of bodies 21 occupies a first volume of a respective one of the accommodation spaces 20. Therein, Fig. 4 shows the rotor 11 and the body 21 after carrying out step S3.

[0053] The method 1 comprises a further step S4 of elastically deforming the respective body 21 or container, respectively, such that it occupies a second volume of the accommodation space 20 being larger than the first volume and such that the body supports the coils 13 of the pair of poles 19, between which the body 21 is arranged.

[0054] In the present embodiment, elastically deforming the container according to step S4 includes pumping the fluid into the container, therein expanding the container inside the accommodation space 20. The fluid is a resin. For pumping the fluid into the container comprises an opening 2.

[0055] The method 1 comprises a further step S5a of curing the resin in a state of the container, in which it occupies a volume being larger than the first volume. Step S5a includes to close the opening 22.

[0056] Fig. 5 is a detailed cross-sectional view of a first embodiment of the rotor device 10 as obtained after carrying out step S5a of the method 1 according to the first embodiment.

[0057] The rotor device 10 comprises the salient-pole rotor 11 as described afore and the elastically deformed bodies 21 arranged inside a respective accommodation space 20 such that a respective one of the bodies 12 supports the coils 13 of the pair of poles 19, between which the body 21 is arranged. Therein, the body 21 is a container filled with cured resin 23.

[0058] In the following further embodiments of the method 1 and the rotor device 10 are described. The embodiments correspond to the respective first embodiments so that only differences with regard to the first embodiments are described. Therein, equivalent or equal components are denoted by identical reference numerals.

[0059] According to a second embodiment of the method 1 , a gaseous fluid 24 is used as fluid in step S4. The fluid 24 may be air. Instead of step S5a, the method 1 according to the second embodiment comprises a step S5b of closing the container in a gastight manner in a state, in which it occupies a volume being larger than the first volume, is provided. For closing the container, the opening 22 is closed.

[0060] Accordingly, the rotor device 10 according to the second embodiment, the body 21 is a container filled with the gaseous fluid 24. The container is closed in a gastight manner.

[0061] Fig. 6 is a detailed cross-sectional view of the rotor 1 1 shown in Fig. 2 having a body 21 arranged in one of the accommodation spaces 20 after carrying out step S3 of a method 1 according to a third embodiment.

[0062] According to the third embodiment of the method 1 , in step S2 the container is provided as a bag being filled with a first component being a resin 25. Further the bag is filled with multiple closed subcontainers 26 filled with a second component being a hardener 27. In step S4, the bag is elastically deformed by applying an outer pressure to the bag as denoted by arrow 28 in Fig. 6. The external pressure causes the subcontainers 26 to rupture and to create a mixture of the resin 25 and the hardener 27. Instead of step S5a, the method 1 according to the third embodiment comprises a step S5c of curing the mixture in a state of the bag, in which it occupies a volume being larger than the first volume.

[0063] According to a modification of the third embodiment, the bag is filled with the hardener 27 and the subcontainers 26 are filled with the resin.

[0064] Fig. 7 is a detailed cross-sectional view of a third embodiment of the rotor device 10 as obtained after carrying out step S5c of the method 1 according to the third embodiment.

[0065] In the rotor device 10 according to the third embodiment, the body 21 is a container filled with a cured mixture 28 of a resin and a hardener and ruptured subcontainers 26’.

[0066] Fig. 8 is a detailed cross-sectional view of the rotor 1 1 shown in Fig. 2 having a body 21 arranged in one of the accommodation spaces 20 after carrying out step S3 of a method 1 according to a fourth embodiment.

[0067] According to the fourth embodiment, a solid body 21 with axial openings 29 and having a rod 30 accommodated in a respective one of the opening 29 is provided in step S2. The rod 30 has an excentric cross-section. In Fig. 8, the rod 30 is exemplarily shown with a substantially oblong cross-sectional shape. In the step S4, the body 21 is elastically deformed by rotating a respective rod 30 about its longitudinal axis as indicated by arrows 31 . Exemplarily, the rods 30 are rotated by 90 degrees.

[0068] Instead of step S5a, the method 1 according to the fourth embodiment comprises a step S5d of fastening a respective rod 30 in its rotated position is provided. Thereto, the rod 30 can be fixed to an end plate (not shown) provided to the rotor According to a modification of the fourth embodiment, the body 21 is provided without having the rod 30 arranged in the opening 29 in step S2. Rather, the rod 30 is inserted in step S4 therein already deforming the body 21 and subsequently rotated in the step S5d as mentioned before.

[0069] Fig. 9 is a detailed cross-sectional view of a fourth embodiment of the rotor device 10 as obtained after carrying out step S5d of the method 1 according to the fourth embodiment.

[0070] According to the fourth embodiment, the body 21 comprises the axial opening 29 and the rod 30 accommodated inside the opening 29. The body 21 is elastically deformed by the rod 30, which has an excentric cross-section and is configured such that the body occupies a smaller volume of the accommodation space 20 when rotating the rod 30 about its longitudinal axis.

[0071] Fig. 10 is a principle drawing of an embodiment of an electric machine 100 in an embodiment of a vehicle 200.

[0072] The electric machine 100 comprises a stator 101 and a rotor device 10 according to any of the preceding embodiments. The rotor device 10 is mounted rotatably relative the stator 101 . The electric machine 100 is an electrically excited synchronous motor.

[0073] The vehicle 200 comprises the electric machine 100, which is configured to propel the vehicle. Thereto, the electric machine 100 is mechanically coupled directly or indirection (e.g., via a gearbox) with wheel 201 of the vehicle.

[0074] In the present embodiment, the vehicle 200 is a battery electric vehicle. Alternatively, the vehicle may comprise an additional combustion engine. In this case, the vehicle 200 is a hybrid vehicle.

Claims

Claims1 . Method (1 ) for manufacturing a rotor device (10) for an electric machine (100), the method (1 ) comprising steps (S1 -S4) of:Providing a salient-pole rotor (1 1 ) having a plurality of poles (19), each pole (19) being formed by a coil (13) wound around a pole section (17) of a rotor core (12) of the rotor (1 1 ), between each circumferentially adjacent pair of poles (19), an accommodation space (20) being formed between the coils (13) of the pair of poles (19);Providing elastically deformable bodies (21 );Arranging the bodies (21 ) into the accommodation spaces (20) such that a respective one of the bodies (21 ) occupies a first volume of a respective one of the accommodation spaces (20); andElastically deforming the respective body (21 ) such that it occupies a second volume of the accommodation space (20) being larger than the first volume and such that the body (20) supports the coils (13) of the pair of poles (19), between which the body (21 ) is arranged.

2. Method according to claim 1 , wherein the body (21 ) is an elastically deformable container for a fluid.

3. Method according to claim 2, wherein the container is elastically deformed by pumping the fluid into the container, therein expanding the container inside the accommodation space (20).

4. Method according to claim 3, wherein the fluid comprises a resin, wherein the method (1 ) comprises a further step (S5a) of:- Curing the resin in a state of the container, in which it occupies a volume being larger than the first volume.

5. Method according to claim 3, whereinthe fluid is gaseous, wherein the method (1 ) comprises a further step (S5b) of: Closing the container in a gastight manner in a state, in which it occupies a volume being larger than the first volume.

6. Method according to claim 2, wherein, the container is provided as a bag being filled with a first component chosen from a group of a resin (25) and a hardener (27) and at least one closed subcontainer (26) filled with a second component being the other member of the group, wherein the bag is elastically deformed by applying an outer pressure to the bag causing the subcontainers (26) to rupture and creating a mixture of the first and second component, wherein the method (1 ) comprises a further step (S5c) of:Curing the mixture in a state of the bag, in which it occupies a volume being larger than the first volume.

7. Method according to claim 1 , wherein the body (21 ) comprises an axial opening (29) for a rod (30) with a longitudinal axis.

8. Method according to claim 7, wherein the body (21 ) is provided with the rod (30) being accommodated in the opening (29); and / or the body (21 ) is elastically deformed by inserting the rod (30) into the opening (29).

9. Method according to claim 8, wherein the rod (30) has an excentric cross-section, wherein the body (21 ) is elastically deformed by rotating the rod (30) about its longitudinal axis.

10. Rotor device (10) for an electric machine (100), the rotor device (10) comprising:a salient-pole rotor (11 ) having a plurality of poles (19), each pole (19) being formed by a coil (13) wound around a pole section (17) of a rotor core (12) of the rotor (11 ), between each circumferentially adjacent pair of poles (19), an accommodation space (20) being formed between the coils (13) of the pair of poles (19); elastically deformed bodies (21 ) arranged inside a respective accommodation space (20) such that a respective one of the bodies (21 ) supports the coils (13) of the pair of poles (19), between which the body (21 ) is arranged.11 . Rotor device according to claim 10, wherein the body (21 ) is a container filled with a gaseous fluid (24), the container being closed in a gas tight manner; or a cured resin (23); or a cured mixture (28) of a resin (25) and a hardener (27) and ruptured subcontainers (26’).

12. Rotor device according to claim 10, wherein the body (21 ) comprises an axial opening (29) and a rod (30) with a longitudinal axis accommodated inside the opening (29), wherein the body (21 ) is elastically deformed by the rod (30).

13. Rotor device according to claim 12, wherein the rod (30) has an excentric cross-section and is configured such that the body (21 ) occupies a smaller volume of the accommodation space (20) when rotating the rod (30) about its longitudinal axis.

14. Electric machine (100) for a vehicle (200), the electric machine (100) comprising: a stator (101 ); a rotor device (10) according to any of claim 10 to 13 or a rotor device (10) obtained by a method (1 ) according to any of claims 1 to 9; the rotor device (10) being mounted rotatably relative the stator (101).

15. Vehicle (200), comprising an electric machine (100) according to claim 14, wherein the electric machine (100) is configured to propel the vehicle (200).

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