Rotor, motor and motor vehicle

Abstract

The invention relates to a rotor (10) for a separately excited machine (12) of an at least partially electrically driven motor vehicle (42), comprising: a laminated core (16) having a longitudinal axis (14), which has at least one pole tooth (18) formed in a direction perpendicular to the longitudinal axis (14) and an end face (20) oriented in the longitudinal direction of the laminated core (16); an insulating cap (22) arranged on the end face (20) and having a deflection structure (24) formed in a direction perpendicular to the longitudinal axis (14), the deflection structure (24) having a head section (26) formed in a direction perpendicular to the longitudinal axis (14); a rotor winding (28) which is arranged on the pole teeth (18) and which is guided at least partially around the deflection structure (24) of the insulating cap (22); and a ring (32) formed tubular on the head section (26) of the deflecting structure (24).

Description

Field of the Invention

[0001] The present invention relates to a rotor of a separately excited electric machine for an at least partially electrically driven motor vehicle, wherein the rotor has a laminated core with at least one pole tooth, and a rotor winding wound around the pole tooth, wherein a ring extending in the circumferential direction of the laminated core is arranged in the region of the winding head of the rotor winding. The present invention also relates to an electric machine having a separately excited electric rotor according to the present invention. Furthermore, the subject matter of the present invention also lies in an at least partially electrically driven motor vehicle having an electric machine according to the present invention. Background Art

[0002] The rotor of a separately excited electric machine is basically known. The rotor typically has a laminated core having a plurality of magnetic poles arranged at intervals from each other in the circumferential direction, wherein the rotor winding is arranged on the magnetic poles. The rotor winding is deflected or formed as a winding head at the end side on the laminated core. The winding heads of the rotor winding are covered in the circumferential direction of the laminated core and at the end side by a winding head cover made of non-magnetized metal. The winding head cover is arranged on the laminated core by screw connection. Summary of the Invention

[0003] The object of the present invention is to provide a rotor for a separately excited electric machine, which can be manufactured at low cost, can have a reduced weight and is designed for high rotational speeds.

[0004] This object is solved by the subject matter of the independent claims. Preferred refinements are the subject matter of the dependent claims, the following description and the drawings. Here, each feature represents an aspect of the present invention both individually and in combination, unless the contrary is explicitly stated in the description, for example.

[0005] In a first aspect, the present invention relates to a rotor of a separately excited electric machine for an at least partially electrically driven motor vehicle, the rotor having: a laminated core having a longitudinal axis, the laminated core having at least one pole tooth formed in a direction perpendicular to the longitudinal axis and an end face oriented in the longitudinal direction of the laminated core; an insulating cap arranged on the end face, the insulating cap having a deflection structure formed in a direction perpendicular to the longitudinal axis, wherein the deflection structure has a head section formed in a direction perpendicular to the longitudinal axis; a rotor winding arranged on the pole tooth, the rotor winding being at least partially guided around the deflection structure of the insulating cap; and a ring arranged on the head section of the deflection structure and formed tubularly.

[0006] In other words, according to the first aspect of the present invention, a rotor for a separately excited electric machine is provided. The electric machine is preferably provided for and / or designed to drive an at least partially electrically driven vehicle.

[0007] The rotor has a laminated core with a longitudinal axis. The laminated core includes at least one pole tooth, where the pole tooth extends in a direction perpendicular to the longitudinal axis. Usually, the laminated core includes a plurality of pole teeth that are spaced apart from each other in the circumferential direction of the laminated core. The pole teeth are preferably spaced apart from each other at regular intervals. In the longitudinal direction of the laminated core, the laminated core has end faces. An insulating cap is arranged on the end faces, and the insulating cap is preferably made of plastic or has plastic. In a direction perpendicular to the longitudinal axis, the insulating cap has a deflection structure, where the deflection structure has a head section in a direction perpendicular to the longitudinal axis. The deflection structure preferably has a cross-section that roughly corresponds to the cross-section of the pole tooth. For example, this means that the outer contour of the cross-section of the pole tooth is similar but not exactly the same as the outer contour of the cross-section of the deflection structure. The deflection structure preferably has a smaller size in the cross-section than the pole tooth, while at the same time maintaining the basic contour or the outer contour.

[0008] The rotor winding is arranged or wound around the pole tooth, where the rotor winding is guided at least partially around the deflection structure of the insulating cap. In other words, the rotor winding extends in the longitudinal direction of the laminated core and is deflected within the range of the deflection structure, so that the rotor winding can be wound around the pole tooth. In this way, a winding head of the rotor winding is formed within the range of the deflection structure. A ring is arranged on the head section of the deflection structure, where the ring is designed to be tubular. The ring can be designed to be tubular before being inserted onto the head section, or can be formed into a tubular shape by winding it onto the head section. The tubular ring can be manufactured inexpensively, thereby reducing the manufacturing cost of the motor. Compared with an end cover that covers most of the end faces of the rotor and the rotor winding with respect to the longitudinal axis, the ring can have less material, thereby reducing the weight of the motor. In other words, the rotor is designed without an end cover. By reducing the material, the manufacturing cost can also be reduced. Since the winding head of the rotor winding is displaced in a direction perpendicular to the longitudinal direction under the influence of centrifugal force due to the rotation of the rotor around the longitudinal axis, the force exerted by the rotor winding is conducted through the deflection structure into the ring arranged on the head section of the deflection structure, and the ring absorbs this force through the hoop stress of the ring. Therefore, especially at high rotational speeds of the rotor, the extension of the winding head in a direction perpendicular to the longitudinal axis of the rotor can be minimized, or a design with a fixed position of the rotor winding within the range of the winding head can be achieved, which is particularly advantageous for high rotational speeds of the rotor (preferably greater than 18,000 revolutions per minute).

[0009] An advantageous improvement of the present invention is that the ring is made of plastic and / or at least partially has plastic. The ring or the tubular ring made of plastic and / or having plastic can be manufactured simply and inexpensively, thereby reducing the manufacturing cost of the motor.

[0010] The plastic is preferably a thermoplastic or a thermosetting plastic. Due to the energization of the rotor winding and the extremely high rotational speed sought for the rotor, the winding heads of the rotor will have an elevated temperature, so that the application of a thermosetting plastic to the ring is preferred.

[0011] It is conceivable that the plastic is designed to be non-reinforced. In this way, the ring can be manufactured inexpensively and can also be easily recycled.

[0012] In an advantageous refinement of the invention, it is provided that the plastic is designed to be fiber-reinforced. The fibers can absorb most of the hoop stress that the ring absorbs due to the rotation of the rotor. Therefore, the size of the ring can be reduced, especially in terms of the cross-section of the ring. The smaller the size of the ring, the lighter the weight of the electric machine will be.

[0013] The fiber-reinforcing material can be arranged and / or formed in the plastic such that the hoop stress is effectively eliminated via the fiber-reinforcing material.

[0014] An advantageous refinement of the invention is that the fiber-reinforcing material is a glass fiber-reinforcing material and / or a carbon fiber-reinforcing material. Thus, it is conceivable that the fiber-reinforcing material consists only of glass fibers, only of carbon fibers or of a mixture of glass fibers and carbon fibers. Glass fibers as well as carbon fibers have a low weight and an increased tensile strength, so that these fibers are particularly suitable for the fiber reinforcement of plastics. Therefore, the weight of the ring can be reduced while increasing the tensile strength.

[0015] In a preferred refinement of the invention, it is provided that the ring is arranged on the head section in a form-fitting and / or material-fitting and / or force-transmitting manner. Preferably, a form-fitting arrangement of the ring on the head section can be achieved by locking the ring using the head section. Furthermore, it is conceivable that the head section has a groove profile or a thread on its radially outwardly facing outer side. In the case of a groove profile, the ring is preferably wound onto the outer side and partially engages in the groove. In the case of a thread, the ring preferably has a mating thread corresponding to the thread on its radially inwardly facing inner side, so that the ring can be screwed onto the outer side. Alternatively or additionally, it is conceivable that the ring can be arranged on the head section in a material-fitting manner via an adhesive connection and / or a welding connection. Furthermore, alternatively or additionally, it can be provided that the ring is pressed onto the outer side of the head section, so that the ring is arranged on the insulator in a force-transmitting manner. In other words, the ring is located on the outer side of the head section in a press fit.

[0016] According to the preferred design of the present invention, the head section has an outer side surface in a direction perpendicular to the longitudinal axis, and this outer side surface is designed as an arc with respect to the circumferential direction of the laminated core. The radius of the arc-shaped outer side surface preferably corresponds to the inner radius of the ring. In this way, the ring can be attached to the outer side surface of the head section over a large area, so that the force generated by the centrifugal force on the rotor winding or the winding head can be guided into the ring over a large area via the deflection section and the head section. In this way, local mechanical stress peaks can be reduced. Therefore, the ring can have a reduced size in cross-section, which can have a beneficial effect on cost and weight.

[0017] In an advantageous refinement of the present invention, it is provided that the outer side surface of the head section is chamfered on the side facing away from the end face. In other words, the head section has a ramp-shaped profile on the side facing away from the end face in the region of the outer side surface. Through the chamfered section, the ring can be guided when it is inserted onto the head section of the deflection section, whereby the ring can be inserted or arranged more simply. Easier insertion of the ring onto the head section can simplify the manufacturing process or accelerate the said manufacturing steps, which can have a positive impact on the manufacturing cost.

[0018] The preferred design of the present invention provides that the head section has a rear locking projection or a rear locking recess on the outer side surface, and a corresponding other one is formed on the inner side surface of the ring. In other words, it can be provided that a projection is formed at least partially, preferably over the entire length of the outer side surface, in the circumferential direction of the laminated core or in the circumferential direction of the arc-shaped outer side surface. Corresponding to the projection, a rear locking recess is formed on the inner side surface of the ring facing the longitudinal axis. This can be, for example, a groove. Alternatively, it can be provided that the projection is formed on the inner side surface of the ring and the rear locking recess is formed on the outer side surface of the head section. By inserting the ring, the head section is slightly bent or deformed inward in the radial direction. Once the rear locking projection engages into the rear locking recess, a return displacement of the head section outward in the radial direction occurs.

[0019] In an advantageous refinement of the present invention, it is provided that the outer diameter of the ring is less than or equal to the outer diameter of the laminated core. In any case, it is not provided that the outer diameter of the ring is greater than the outer diameter of the laminated core. For the ring stress to be absorbed by the ring, it is advantageous for the ring to be as large as possible. Therefore, it is particularly advantageously provided that the outer diameter of the ring is equal to the outer diameter of the laminated core.

[0020] In principle, it can be envisaged that the ring has a length in the longitudinal direction of the rotor, and this length is greater than the length of the head section in the longitudinal direction of the rotor.

[0021] Advantageously, it is provided that the length of the ring in the longitudinal direction of the rotor is less than or equal to the length of the insulating cap or the head section in the longitudinal direction of the rotor. In this way, the length of the ring can preferably be limited to the length of the contact surface for the head section in the longitudinal direction. Thus, not only can the material of the ring be reduced, but also the installation space in the longitudinal direction can be reduced. This also has a beneficial effect on the weight and cost of the electric machine.

[0022] It is conceivable that in an alternative, the length of the ring in the longitudinal direction of the rotor is greater than the length of the insulating cap or the head section in the longitudinal direction of the rotor. This can be advantageous within the scope of the rotor in the case of liquid cooling of the electric machine in order to specifically distribute or guide the cooling medium.

[0023] In a second aspect, the invention relates to an electric machine having a rotor according to the invention.

[0024] The electric machine is preferably arranged and / or designed for being arranged in the drivetrain of at least a partially electrically driven vehicle.

[0025] In a third aspect, the invention relates to a motor vehicle having an electric machine according to the invention.

[0026] The motor vehicle is preferably at least partially, preferably fully electrically driven. The electric machine is located in the drivetrain, in particular in the traction drive of the vehicle.

[0027] It should be noted that all features described above and below for one aspect of the invention equally apply to any other aspect of the invention. All features of the rotor can in particular also be features of the electric machine and / or features of the motor vehicle. And vice versa. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Further features and advantages of the invention result from the dependent claims and the following embodiments. The embodiments should not be understood as restrictive, but rather as exemplary. They should enable a person skilled in the art to implement the invention. The applicant reserves the right to claim individual and / or multiple features disclosed in the embodiments as the subject matter of patent claims or to incorporate these features into existing patent claims. The embodiments are explained in more detail with reference to the drawings.

[0029] Shown therein are:

[0030] Figure 1 a three-dimensional view of the rotor;

[0031] Figure 2 a cross-section showing a three-dimensional view of the rotor;

[0032] Figure 3 a longitudinal sectional view of the rotor;

[0033] Figure 4Shows a longitudinal sectional view of the rotor in another design;

[0034] Figure 5 Shows a motor vehicle. Detailed implementation

[0035] Figure 1 A three - dimensional view of the rotor 10 for a separately - excited electric machine 12 is shown. The rotor 10 has a laminated core 16, which has a longitudinal axis 14. The laminated core 16 is arranged in a rotation - resistant manner on the rotor shaft 17, which can also be referred to as the shaft. The laminated core 16 includes at least one pole tooth 18, where the pole tooth 18 extends in a direction perpendicular to the longitudinal axis 14. As Figure 1 shown, the laminated core 16 generally includes a plurality of pole teeth 18, which are arranged at intervals from each other in the circumferential direction of the laminated core 16. In the longitudinal direction of the laminated core 16, the laminated core 16 has end faces 20.

[0036] An insulating cap 22 is arranged on the end face 20, which is preferably made of or has plastic. In a direction perpendicular to the longitudinal axis 14, the insulating cap has a deflection structure 24, where the deflection structure 24 has a head section 26 in a direction perpendicular to the longitudinal axis 14.

[0037] The rotor winding 28 is arranged on the pole teeth 18, where the rotor winding 28 is at least partially guided around the deflection structure 24 of the insulating cap 22. In other words, the rotor winding 28 extends in the longitudinal direction of the laminated core 16 and is deflected in the region of the deflection structure 24, so that the rotor winding 28 can or is wound around the pole teeth 18. In this way, a winding head 30 of the rotor winding 28 is formed in the region of the deflection structure 24.

[0038] In Figure 1 a ring 32 is arranged and designed to be arranged on the head section 26 of the deflection structure 24, which is arranged at a distance from the rotor 10 in the longitudinal direction. The ring 32 is designed to be tubular. In other words, in the shown embodiment, the ring 32 is designed to be tubular before being inserted onto the head section 26.

[0039] The tubular ring 32 can be manufactured at low cost, thereby reducing the manufacturing cost of the electric machine 12. Compared with an end cover that covers most of the end face 20 of the rotor 10 and the rotor winding 28 with respect to the longitudinal axis 14, the ring 32 can have less material, thereby reducing the weight of the electric machine 12. By reducing the material, the manufacturing cost can also be reduced. Since the rotation of the rotor 10 around the longitudinal axis 14 causes the winding heads 30 of the rotor winding 28 to shift in a direction perpendicular to the longitudinal axis 14 under the influence of centrifugal force, the force exerted by the rotor winding 28 is conducted via the deflection structure 24 into the ring 32 arranged on the head section 26 of the deflection structure 24, and the ring absorbs this force via the hoop stress of the ring 32. Therefore, especially at high rotational speeds of the rotor 10, the extension of the winding heads 30 in a direction perpendicular to the longitudinal axis 14 of the rotor 10 can be minimized, or in other words, a design with the position of the rotor winding 28 fixed within the range of the winding heads 30 can be achieved, which is particularly advantageous for high rotational speeds of the rotor 10 (preferably greater than 18,000 revolutions per minute).

[0040] Furthermore, it can be seen that the head section 26 has an outer side face 34 in a direction perpendicular to the longitudinal axis 14, and the outer side face 34 is designed as an arc with respect to the circumferential direction of the laminated core 16. Here, the radius of the arc-shaped outer side face 34 corresponds to the inner radius of the ring 32. In this way, the ring 32 can be attached to the outer side face 34 of the head section 26 over a large area, so that the force generated by the centrifugal force of the rotor winding 28 or the winding heads 30 can be guided into the ring 32 over a large area via the deflection section 24 and the head section 26. In this way, local mechanical stress peaks can be reduced. Therefore, the ring 32 can have a reduced size in cross-section, which can have a beneficial effect on the cost and weight of the rotor 10 or the electric machine 12.

[0041] Figure 2 A longitudinal section of a three-dimensional view of the rotor 10 known from Figure 1 is shown, in which the ring 32 is inserted on the head section 26 of the deflection structure 24.

[0042] When the deflection structure 24 and the head section 26 are observed together, the cross-section is designed as an L-shape. Here, the vertical tab corresponds to the L-shaped design of the deflection structure 24, which abuts on the end face 20 of the laminated core 16 or extends parallel to the end face 20. The shorter horizontal tab of the L-shaped design corresponds to the head section 26. The head section 26 extends parallel to the longitudinal axis 14 or extends at a right angle to the end face 20 of the laminated core 16.

[0043] The outer side surface 34 of the head section 26 is designed to be chamfered 36 on the side facing away from the end face 20. In other words, the head section 26 has a ramp-shaped profile on the side facing away from the end face 20 in the region of the outer side surface 34. The chamfer section 36 can guide the ring 32 when it is inserted onto the head section 26 of the deflection section 24, whereby the ring 32 can be inserted or arranged more simply. Inserting the ring 32 onto the head section 26 more easily can simplify the manufacturing process or accelerate the manufacturing steps, which can have a positive impact on the manufacturing cost of the rotor 10.

[0044] Figure 3 is shown for Figure 2 a longitudinal section of the known rotor 10. It can be seen in the longitudinal section that the outer diameter of the ring 32 is equal to the outer diameter of the laminated core 16. In any case, it is not stipulated that the outer diameter of the ring 32 is greater than the outer diameter of the laminated core 16. In this way, the rotor 10 together with the ring 32 can be completed for subsequent arrangement in a stator (not shown). So when the ring 32 is as large as possible, it is advantageous for the ring stress to be absorbed by the ring 32. Therefore, it is particularly advantageously stipulated that the outer diameter of the ring 32 is equal to the outer diameter of the laminated core 16.

[0045] The length of the ring 32 in the longitudinal direction of the ring 32 or the rotor 10 is equal to the length of the head section 26 in the longitudinal direction of the rotor 10. In other words, relative to the longitudinal view of the rotor 10, the ring 32 does not cover the end face 20 or the rotor winding 28 over a large area. In addition, the length of the ring 32 can be limited in the longitudinal direction to the length of the contact surface 26, preferably without considering the chamfer section 36. In this way, not only can the material of the ring 32 be reduced, but also the installation space of the rotor 10 in the longitudinal direction can be reduced. This can also have a beneficial impact on the weight and cost of the electric machine 12.

[0046] Figure 4 is shown for Figure 3 a longitudinal section of the known rotor 10. Compared with Figure 3Differently, the head section 26 has a rear locking projection 38 on the outer side surface 34. A rear locking recess 40 is formed on the inner side surface of the ring 32. In other words, it is stipulated that a projection is formed at least partially on the outer side surface 34, preferably over the entire length of the outer side surface 34, in the circumferential direction of the laminated core 16 or in the circumferential direction of the arcuate outer side surface 34. Corresponding to the projection, a rear locking recess 40 is formed on the inner side surface of the ring 32 facing the longitudinal axis 14. The rear locking recess 40 is preferably designed to be circumferential in the circumferential direction of the ring. The rear locking recess 40 may preferably be a groove. By inserting the ring 32 onto the head section 26, the head section is slightly bent or deformed radially inwards (i.e., in a direction perpendicular to the longitudinal axis 14). Once the rear locking projection 38 engages into the rear locking recess 40, a return displacement of the head section 26 radially outwards occurs. Thus, the ring 32 can be arranged in a form-fitting and anti-loss manner on the head section 26 in a simple and inexpensive way.

[0047] In Figure 5 FIG. shows a motor vehicle 42 having an electric machine 12. The motor vehicle 42 is an at least partially electrically driven motor vehicle 42. The electric machine 12 is located in the driveline of the motor vehicle 42, in particular in a traction drive device.

Claims

1. A rotor (10) of a separately excited electric machine (12) for an at least partially electrically driven motor vehicle (42), the rotor having: a laminated core (16) having a longitudinal axis (14), the laminated core having at least one pole tooth (18) formed in a direction perpendicular to the longitudinal axis (14) and end faces (20) oriented in the longitudinal direction of the laminated core (16); an insulating cap (22) arranged on the end face (20), the insulating cap having a deflection structure (24) formed in a direction perpendicular to the longitudinal axis (14), wherein, The deflection structure (24) has a head section (26) formed in a direction perpendicular to the longitudinal axis (14); a rotor winding (28) arranged on the pole teeth (18), the rotor winding being guided at least partially around the deflection structure (24) of the insulating cap (22); and a ring (32) arranged on the head section (26) of the deflection structure (24) and formed tubularly.

2. The rotor according to claim 1, wherein The ring (32) is made of plastic and / or at least partially has plastic.

3. The rotor according to claim 2, wherein, The plastic is designed to be fiber-reinforced.

4. The rotor according to claim 3, wherein The fiber-reinforcing material is a glass fiber-reinforcing material and / or a carbon fiber-reinforcing material.

5. The rotor according to any one of the preceding claims, characterized in that, The ring (32) is arranged on the head section (26) in a form-fitting and / or material-fitting and / or force-transmitting manner.

6. The rotor according to any one of the preceding claims, characterized in that, The head section (26) has an outer side surface (34) in a direction perpendicular to the longitudinal axis (14), and the outer side surface (34) is designed to be arcuate with respect to the circumferential direction of the laminated core (16).

7. The rotor according to claim 6, characterized in that, The outer side surface (34) of the head section (26) is chamfered (36) on a side facing away from the end face (20).

8. The rotor according to claim 6 or 7, characterized in that, The head section (26) has a rear locking projection (38) or a rear locking recess (40) on the outer side surface (34), and the corresponding other one is formed on the inner side surface of the ring (32).

9. The rotor according to any one of the preceding claims, characterized in that, The outer diameter of the ring (32) is less than or equal to the outer diameter of the laminated core (16).

10. The rotor according to any one of the preceding claims, characterized in that, The length of the ring (32) in the longitudinal direction of the rotor (10) is less than or equal to the length of the insulating cap (22) or the head section (26) in the longitudinal direction of the rotor (10).

11. The rotor according to any one of claims 1 to 9, characterized in that, The length of the ring (32) in the longitudinal direction of the rotor is greater than the length of the insulating cap (22) or the head section (26) in the longitudinal direction of the rotor (10).

12. An electric machine (12) having a rotor (10) according to any one of the preceding claims.

13. A motor vehicle (42) having an electric machine according to claim 12.

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