Power transmission arrangement for transmitting power to a rotor arrangement of a separately excited electrical machine, rotor arrangement comprising the power transmission arrangement, and separately excited electrical machine comprising the rotor arrangement

Abstract

The present invention relates to a power transmission arrangement (1), in particular an inductive power transmission arrangement, for transmitting power to a rotor arrangement (50) of a separately excited electrical machine (100), comprising a primary arrangement (3) and a secondary arrangement (5) for transmitting electrical power, a carrier shaft (7) connected to the primary arrangement (3) for conjoint rotation and a functional element (9), wherein the carrier shaft (7) is mounted rotatably in the functional element (9) and the functional element (9) is designed to be able, within a receiving area (51a) in a rotor shaft (51), to be coupled to the rotor shaft (51) for conjoint rotation. The invention furthermore relates to a rotor arrangement (50) comprising the power transmission arrangement (1) according to the invention, and to a separately excited electrical machine (100) comprising the rotor arrangement (50) according to the invention.

Description

[0001] ZF Friedrichshafen AG Friedrichshafen

[0002] Power transfer arrangement for power transfer to a rotor arrangement of an externally controlled electrical machine, rotor arrangement with the power transfer arrangement and externally controlled electrical machine with the rotor arrangement

[0003] The present invention relates generally to a power transmission arrangement, in particular to an inductive power transmission arrangement, a rotor arrangement and a separately excited electrical machine.

[0004] Power transmission arrangements are generally known. Particularly in the field of separately excited electric motors, power transmission arrangements play an increasingly important role as exciters for power transmission. Separately excited electric motors generally offer the advantage of eliminating the need for permanent magnets or rare earth elements.

[0005] In separately excited electric motors, the magnetic rotor field is generated by a current flowing through the rotor. The electrical energy has traditionally been transferred conductively via a sliding contact as a contact transformer. However, this physical contact results in the disadvantage of increased friction in the rotor system. Furthermore, wear and tear builds up over time. Therefore, the contact transformer is positioned in its own sealed chamber to prevent wear particles from entering the rotor / gearbox system. This results in the disadvantage of requiring additional installation space and increasing weight.

[0006] Inductive power transmission offers an alternative to the conductive system. Inductive power transmission not only eliminates the need for permanent magnets, but also eliminates the sliding contacts and the sealed space required for them. Inductive energy transmission saves installation space, reduces wear, and increases the system's power density. With inductive power transmission, an alternating current provided by the power electronics can be transmitted contactlessly through an inductive (current / rotary) transmission device. Such an inductive transmission device can be a (e.g., rotationally symmetrical) transformer comprising a primary assembly and a secondary assembly, wherein the primary assembly comprises a primary ferrite core with associated primary windings, and the secondary unit comprises a secondary ferrite core with associated secondary windings.The primary winding (coil) generates a magnetic field that is concentrated by the ferrite core(s). The primary ferrite core and the secondary ferrite core are separated by an air gap. Typically, the primary unit is fixed in place within the electrical machine, e.g., on the housing, while the secondary unit is rotatable, e.g., through a rotationally fixed connection to the rotor.

[0007] The inductive transmission device allows an alternating current to be transmitted contactlessly from the primary winding of the primary unit to the secondary winding of the secondary unit. A rectifier board connected to the secondary winding taps the transmitted alternating current and converts it into direct current to power the rotor winding.

[0008] The power transmission unit typically comprises a primary assembly and a secondary assembly that are rotatable relative to one another. Both the primary assembly and the secondary assembly each comprise a ferrite and a magnetic coil arranged around it. A design that has proven successful so far is one in which the cylindrical primary assembly is aligned axially within the cylindrical secondary assembly. The two magnetic coils are arranged overlapping between them. The primary assembly is firmly connected to the housing, and the secondary assembly is non-rotatably connected to the rotor. The circumferential air gap between the ferrite of the primary assembly and the ferrite of the secondary assembly forms the transmission surface and is crucial for efficient power transmission.

[0009] The air gap is formed at each end section and the overlapping coils are arranged in the middle section. The air gap should be as small as possible in the radial direction, for example less than 1 mm. However, the air gap is limited downwards by taking tolerances and play into account. For the best possible efficiency, the primary and secondary arrangements must be aligned as precisely as possible in the axial direction. The problem with the known design is that if the entire rotor has axial play within the housing, the secondary arrangement shifts axially relative to the primary arrangement. The play can result from tolerances or bearing play, for example. This play has a direct influence on the efficiency and effectiveness of the power transmission, since the play changes the transmission area in the air gap.

[0010] This problem has so far been addressed by making the two ferrites of the primary and secondary assembly axially longer than necessary to compensate for the axial play within the transmission surface. Furthermore, compensation for tolerance influences has so far been achieved through complex manual alignment and assembly of the primary assembly. This increases assembly costs and weight.

[0011] The object of the present invention is therefore to provide a power transmission arrangement, a rotor arrangement and a separately excited electrical machine in which the disadvantages mentioned above are at least partially reduced.

[0012] This object is achieved by a power transmission arrangement according to claim 1, a rotor arrangement according to claim 9 and a separately excited electrical machine according to claim 12.

[0013] Further aspects and features of the present invention emerge from the dependent claims, the accompanying drawings and the following description of embodiments.

[0014] According to a first aspect, the present invention provides a power transmission arrangement, in particular an inductive power transmission arrangement, for transmitting power to a rotor arrangement of a separately excited electrical machine, comprising a primary arrangement and a secondary arrangement for electrical power transmission, a carrier shaft that is rotationally fixedly connected to the primary arrangement, and a functional element. The carrier shaft is rotatably mounted in the functional element, and the functional element is designed to be rotationally fixedly coupled to the rotor shaft within a receiving area in a rotor shaft. The power transmission arrangement can be an exciter.

[0015] The functional element can be designed to be non-rotatably coupled to the rotor shaft.

[0016] The primary assembly, the secondary assembly, the carrier shaft, and the functional element can be arranged concentrically or coaxially around a rotational axis of the rotor assembly. The primary assembly and the secondary assembly can have the same length in an axial direction.

[0017] The primary arrangement may comprise a primary ferrite. The primary arrangement may comprise a primary winding. The primary winding may be arranged in a rotationally fixed manner around the primary ferrite. The primary ferrite may be cylindrical. The primary ferrite may have a T-shaped cross-section. A disc-shaped collar may be formed on one side of the primary ferrite.

[0018] The secondary arrangement may comprise a secondary ferrite. The secondary arrangement may comprise a secondary winding. The secondary winding may be arranged in a rotationally fixed manner within the secondary ferrite. The secondary ferrite may be cylindrical. The secondary ferrite may have a U-shaped cross-section.

[0019] The primary arrangement can be arranged within the secondary arrangement. The primary arrangement and secondary arrangement can together form a cylindrical outer geometry. The primary arrangement can be arranged so as to be rotatable relative to and within the secondary arrangement. An air gap can be formed between the primary arrangement and the secondary arrangement. The air gap can be formed in the region of an end section. The end section can be an end section of the cylindrical outer geometry located in the axial direction. The end section can encompass the end face. The air gap can be formed in the region of both end sections.

[0020] The length of the air gap in the axial direction can correspond to a transmission length. A transmission surface can be formed within the air gap along the circumferential direction.

[0021] The carrier shaft can have multiple shaft shoulders. The primary assembly can be positively connected to the carrier shaft for rotation. One of the multiple shaft shoulders can serve as an axial stop for the primary assembly.

[0022] The carrier shaft and the primary assembly can be rotatably mounted in the functional element. The functional element can be axially fixed to the secondary assembly. The primary assembly can be aligned in the axial direction relative to the secondary assembly via the functional element. The primary assembly can be aligned in the axial direction relative to the secondary assembly via the functional element.

[0023] The primary assembly, the carrier shaft, and the functional element can form a common subassembly. The subassembly can be preassembled. The preassembled subassembly can be designed to be coupled to the rotor shaft within the receiving area. This can reduce assembly effort.

[0024] The power transmission arrangement according to the invention makes it possible to decouple the influence of axial play in the rotor arrangement on the alignment of the primary arrangement to the secondary arrangement. As a result, the air gap between the primary arrangement and the secondary arrangement remains identical even when the rotor arrangement is axially displaced. As a result, the transmission area remains identical. This allows efficient power transmission during operation despite axial play between the rotor arrangement and a housing. The arrangement according to the invention makes it possible to design the primary arrangement and the secondary arrangement shorter in the axial direction. This saves weight and material. Furthermore, the power transmission arrangement can be arranged entirely within the rotor shaft. This saves installation space.

[0025] Before a detailed description of the figures, general remarks on the embodiments follow.

[0026] The term "power transfer assembly" describes an exciter or field generator of an electrical machine. The power transfer assembly generally serves to induce electrical energy from a power electronics system into the rotor winding.

[0027] There are embodiments in which the functional element comprises a coupling section which is designed to couple the functional element to the rotor shaft in a rotationally fixed manner within the receiving area in the rotor shaft.

[0028] The coupling section can be arranged in an outer region of the functional element. The functional element can be positively coupled to the rotor shaft via the coupling section. The functional element can be force-fitted to the rotor shaft via the coupling section. The functional element can be positively and force-fitted to the rotor shaft via the coupling section. The functional element can be materially coupled to the rotor shaft via the coupling section.

[0029] The secondary assembly can be clamped to the coupling section via the functional element. The secondary assembly and the functional element can have a substantially identical outer diameter. Alternatively, the secondary assembly can be clamped using a combination of a retaining ring and a spring.

[0030] The coupling section can be a threaded section. The threaded section can be an external thread. Alternatively, the coupling section can be designed according to a shaft-hub connection. Alternatively, the coupling section can be a section for a material connection. The coupling section can further comprise a force introduction area. The force introduction area can be arranged on the end face of the functional element. The force introduction area can be accessible via an end face of the rotor shaft during assembly. For example, the functional element can be mounted in a rotationally fixed manner into the receiving area of ​​the rotor shaft using a tool via the force introduction area.

[0031] There are designs in which the functional element is disc-shaped.

[0032] The disc-shaped functional element can be arranged concentrically or coaxially to the rotation axis. The functional element can be disc-shaped or cylindrical. The coupling section can be formed in an outer radial section along the circumferential direction. An external thread can be formed on the disc-shaped functional element in the outer radial section.

[0033] There are embodiments in which a bearing seat is formed in the functional element in which the carrier shaft is rotatably mounted.

[0034] The bearing seat can be arranged concentrically or coaxially to the rotational axis. The bearing seat can be designed like a hub in the functional element. A bearing can be arranged in the bearing seat. Multiple bearings can be arranged in the bearing seat. The bearing can be a rolling bearing. The force introduction area can be arranged in the radial direction between the bearing seat and the coupling section. The carrier shaft can be rotatable relative to the functional element. The carrier shaft and the primary assembly can be rotatable together relative to the functional element.

[0035] There are embodiments in which the primary assembly is fixed to the secondary assembly in the axial direction along the rotational axis of the rotor shaft. The primary assembly can be fixed axially to the secondary assembly. The functional element can be fixed to the secondary assembly in the axial direction. The fixation in the axial direction can be achieved via the functional element. The fixation can be achieved via the coupling section on the functional element.

[0036] The axial play of the rotor shaft can be decoupled from the axial alignment of the primary assembly to the secondary assembly. The alignment of the primary assembly to the secondary assembly can remain identical despite axial movement of the rotor shaft. This ensures that the air gap for power transmission between the primary ferrite and secondary ferrite remains unchanged during operation. As a result, the transmission length and the transmission area remain unchanged even during axial movement of the rotor shaft. This allows for constant power transmission during operation.

[0037] The functional element and the primary assembly can be configured such that they form a common receiving space. A printed circuit board can be arranged in the receiving space. A conductor arrangement can be arranged in the receiving space.

[0038] There are embodiments in which the power transmission arrangement further comprises a retaining ring, wherein the retaining ring is arranged in the axial direction between the secondary arrangement and the functional element.

[0039] The retaining ring can be ring-shaped. The retaining ring can secure the secondary assembly against rotation during assembly. The retaining ring can be designed such that it can be coupled in a rotationally fixed manner to an inner surface of the rotor shaft.

[0040] The retaining ring can secure the secondary assembly against rotation during assembly of the primary assembly over the functional element. The retaining ring can absorb a torque during assembly of the functional element, thereby preventing torque from being introduced into the secondary assembly. The retaining ring can, among other things, fulfill the function of a shim. The axial position of the functional element can be adjusted via the axial width of the retaining ring. The axial position of the primary assembly can be adjusted via the axial width of the retaining ring. The functional element can be designed to clamp the secondary assembly.

[0041] An anti-rotation device can be formed on the retaining ring. The anti-rotation device can be formed in the outer casing area. The anti-rotation device can comprise several locking elements. The locking elements can be ear-shaped. The locking elements can be arranged circumferentially around the retaining ring.

[0042] Furthermore, a spring element can be arranged between the functional element and the retaining ring. A predefined spring force can be used to set a specific screw-in depth of the functional element in the axial direction. The screw-in depth of the functional element can be used to align the primary assembly with the secondary assembly in the axial direction.

[0043] There are embodiments in which a fixing section is formed on the support shaft for the rotationally fixed fixing of the support shaft.

[0044] The fixing section can protrude from the functional element. The carrier shaft can be fixed via the fixing section in a rotationally fixed manner to a relative movement of the secondary assembly. The fixing can be achieved by means of a positive fit.

[0045] The fixing section can be formed in an end section of the support shaft. The fixing section can be designed such that the support shaft remains displaceable in the axial direction. The fixing section can prevent rotational movement of the primary assembly.

[0046] There are embodiments in which a cable guide is formed on the support shaft for the passage of a conductor arrangement. The cable guide can comprise a hollow shaft section in the support shaft. The cable guide can further comprise a radial bore. A cable can be routed axially outward via the radial bore and the hollow shaft section.

[0047] A second aspect of the application relates to a rotor arrangement for the separately excited electrical machine, wherein the rotor arrangement comprises the power transmission arrangement according to the invention and a hollow rotor shaft which are arranged about a common axis of rotation, wherein the power transmission arrangement is arranged within the receiving area in the rotor shaft.

[0048] The receiving area can be formed within the hollow rotor shaft. The hollow rotor shaft can be a hollow shaft. The power transmission assembly can be arranged entirely within the rotor shaft.

[0049] The functional element can be non-rotatably coupled to the rotor shaft. The functional element can be non-rotatably coupled to the rotor shaft within the receiving area.

[0050] The functional element can be coupled to the rotor shaft via the coupling section within the receiving area. The functional element can be positively coupled to the rotor shaft via the coupling section. The functional element can be force-fitted to the rotor shaft via the coupling section. The functional element can be positively and force-fitted to the rotor shaft via the coupling section. The functional element can be materially coupled to the rotor shaft via the coupling section. The secondary assembly can be clamped to the coupling section via the functional element.

[0051] The functional element can be secured against loosening by an additional locking element in the area of ​​the front side of the rotor shaft. A threaded section can be formed in the receiving area in the rotor shaft. The threaded section can be an internal thread. In a case where the coupling section of the functional element is an external thread, the functional element can be screwed into the receiving area in an axial direction along the axis of rotation. By screwing in the functional element, the secondary assembly can be clamped in the receiving area of ​​the rotor shaft.

[0052] The carrier shaft can protrude from the rotor shaft. The carrier shaft can protrude from one end of the rotor shaft. The carrier shaft can protrude from the rotor shaft on one side.

[0053] The joint subassembly, comprising the primary assembly, the carrier shaft, and the functional element, can be pre-assembled and inserted into the receiving area of ​​the rotor shaft. The subassembly can be mechanically coupled to the rotor shaft via the coupling section on the functional element. This reduces assembly effort.

[0054] There are embodiments in which the functional element and the secondary arrangement are coupled in a rotationally fixed manner to an inner side of the receiving area.

[0055] The secondary assembly can be firmly connected to the inside of the receiving area by a material fit. The secondary assembly can be firmly connected to the inside via an adhesive connection.

[0056] The secondary assembly can be positively coupled to the inside of the receiving area in a rotationally fixed manner. The secondary assembly can be rotationally fixed to the inside via a shaft-hub connection.

[0057] An axial stop can be formed within the receiving area. The secondary assembly can be positioned in the axial direction via the axial stop. An outer circumferential geometry of the secondary assembly can be complementary to an inner circumferential geometry of the receiving area. This allows the secondary assembly to be fixed in the radial direction within the receiving area. This allows the secondary assembly to be aligned concentrically or coaxially with the rotation axis.

[0058] The secondary arrangement and the receiving area can each have a round cross-section. An outer diameter of the secondary arrangement can substantially correspond to an inner diameter of the receiving area.

[0059] The retaining ring can be arranged within the receiving area. The retaining ring can be coupled to the receiving area via the anti-rotation device. The retaining ring can be arranged axially between the functional element and the secondary arrangement.

[0060] The retaining ring can be used to decouple the already assembled secondary assembly from the introduction of torque when screwing in the functional element. The retaining ring can be used to influence the axial installation position of the functional element relative to the secondary assembly. The retaining ring can be used to influence the axial installation position of the primary assembly relative to the secondary assembly.

[0061] There are embodiments in which a bearing seat is formed within the rotor shaft and the carrier shaft is rotatably mounted in the bearing seat and in the functional element.

[0062] The carrier shaft can be rotatably mounted in the bearing seat of the rotor shaft and the bearing seat of the functional element.

[0063] A bearing can be arranged in the bearing seat of the rotor shaft. Multiple bearings can be arranged in the bearing seat of the rotor shaft. A third aspect of the application relates to the separately excited electrical machine, comprising the rotor assembly according to the invention, a stator assembly, and a housing assembly.

[0064] The separately excited electrical machine can be a separately excited synchronous electrical machine (SESM).

[0065] The rotor assembly can be rotatably mounted within the stator assembly. The rotor assembly can be rotatably mounted in a bearing section of the housing assembly. A rotor bearing assembly can be arranged in the bearing section.

[0066] There are embodiments in which the primary arrangement is electrically coupled to a power electronics system via a cable arrangement that is flexible in the axial direction.

[0067] The cable arrangement can run along the cable guide on the carrier shaft. The cable arrangement can run within the cable guide of the carrier shaft. The flexible cable arrangement can be designed to be flexible enough to compensate for the axial play of the rotor arrangement. The cable arrangement can be a conductor of the primary arrangement. The conductor can be electrically connected to the primary winding.

[0068] There are embodiments in which the carrier shaft is fixed in a rotationally fixed manner to the housing arrangement via a fixing section.

[0069] Despite the rotationally fixed fixation, the carrier shaft can be displaceable along the axial direction. The carrier shaft can be fixed in a rotationally fixed manner to a relative movement of the secondary assembly via the fixing section. The fixing can be positively locked. The fixing section can prevent rotational movement of the primary assembly. The fixing section of the carrier shaft can protrude from the rotor shaft. The fixing section of the carrier shaft can protrude from the rotor assembly.

[0070] The carrier shaft with the fixing section can be fixed to the housing assembly via a securing part located on the housing assembly. The securing part can be mounted on the housing assembly.

[0071] The invention is explained in more detail below by way of example and with reference to the accompanying figures. Identical or similar components are designated by identical reference numerals. They show:

[0072] Fig. 1 is a longitudinal sectional view of a primary arrangement with a carrier shaft and a functional element of a power transmission arrangement according to the invention;

[0073] Fig. 2 is a longitudinal sectional view of a secondary arrangement of the power transmission arrangement according to the invention;

[0074] Fig. 3 is a longitudinal sectional view of the power transmission arrangement according to the invention;

[0075] Fig. 4 shows several schematic cross-sectional views of further embodiments for coupling a functional element to a rotor shaft;

[0076] Fig. 5a is a longitudinal sectional view of a separately excited electrical machine according to the invention with a rotor arrangement according to the invention; and

[0077] Fig. 5b a detailed view from Fig. 5a with a fixing section on a carrier shaft.

[0078] Fig. 1 shows a longitudinal sectional view of a primary arrangement 3 with a carrier shaft 7 and a functional element 9 of a power transmission arrangement 1 according to the invention. The primary arrangement 3 comprises a cylindrical primary ferrite 3f and a primary winding 3w. A disk-shaped collar is formed on one side of the cylindrical primary ferrite 3f. The primary winding 3w is wound around the primary ferrite 3f in a central section. The carrier shaft 7 completely penetrates the primary arrangement 3. The carrier shaft 7 is aligned concentrically or coaxially with the primary arrangement 3. The carrier shaft 7 protrudes from the primary arrangement 3 on both sides.

[0079] To the left of the primary assembly 3, the disc-shaped or wheel-shaped functional element 9 is arranged on the carrier shaft 7. The functional element 9 is aligned concentrically with the carrier shaft 7.

[0080] A bearing seat 9b is formed in a hub area of ​​the functional element 9. A bearing 17 is arranged in the bearing seat 9b. The support shaft 7 is rotatably mounted in the functional element 9 via the bearing 17 in the bearing seat 9b.

[0081] A coupling section 9a is arranged in an outer region of the disc-shaped functional element 9. The coupling section 9a is designed as an external thread. A force introduction region 9c is formed on the functional element 9 on a front side facing away from the primary assembly 3.

[0082] On an end face facing the primary assembly 3, a retaining ring 11 is arranged next to the functional element 9. The retaining ring 11 extends along a circumferential direction of the functional element 9. Furthermore, the retaining ring 11 covers a radial end-face section of the coupling section 9a of the functional element 9.

[0083] The primary assembly 3, the retaining ring 11, and the side of the functional element 9 facing the primary assembly 3 form a common receiving space. A printed circuit board 15 is arranged in the receiving space. The printed circuit board 5 is arranged on the disc-shaped collar of the primary ferrite 3f.

[0084] To the left of the primary arrangement 3, a cable guide 7b is formed in the carrier shaft 7. The cable guide 7b comprises a hollow shaft section and a radial bore arrangement. A conductor arrangement 13 runs through the cable guide 7b. The conductor arrangement 13 is electrically connected to the circuit board 15. Fig. 2 shows a longitudinal sectional view of a secondary arrangement 5 of the power transmission arrangement 1 according to the invention. The secondary arrangement 5 comprises a cylindrical secondary ferrite 5f and a secondary winding 5w. The cylindrical secondary ferrite 5f has a U-shaped cross-section. The secondary winding 5w is arranged in the region of an inner circumferential surface of the secondary ferrite 5f. A round recess for receiving the primary arrangement 3 is formed in a bottom region of the U-shaped cross-section.

[0085] A rectifier arrangement 19 is arranged externally at the bottom area of ​​the secondary ferrite 5f.

[0086] Fig. 3 shows the power transmission assembly 1 according to the invention in a longitudinal section. The power transmission assembly 1 comprises the components shown in Fig. 1 and Fig. 2. The primary assembly 3, secondary assembly 5, carrier shaft 7, and functional element 9 are arranged within a receiving area 51b of a rotor shaft 51.

[0087] A bearing seat 51c is formed within the receiving area 51b. A bearing 53 is arranged in the bearing seat 51c. An internal thread is formed on the inner side 51b of an end section of the receiving area 51b.

[0088] The secondary assembly 5 is inserted into the inner surface 51b of the receiving area 51a via the secondary ferrite 5f. A rectifier assembly 19 is arranged between the secondary assembly 5 and the bearing seat 51c. The rectifier assembly 19 is connected to a rotor connection line 21. The rotor connection line 21 is led radially out of the rotor shaft 51 via radial bores in the rotor shaft 51.

[0089] In contrast to Fig. 1 and Fig. 2, in Fig. 3 the primary arrangement 3 with the carrier shaft 7 is pushed into the secondary arrangement 5 along an axial direction A. The primary arrangement 3 is completely pushed into the secondary arrangement 5. The primary arrangement 3 and the secondary arrangement 5 are arranged concentrically or coaxially around the axis of rotation R. The primary arrangement 3 and the secondary arrangement 5 together form a cylindrical body. The primary arrangement 3 and the secondary arrangement 5 each form a common end face at the two end sections of the cylindrical body. An air gap 6 with a transmission surface for inductive power transmission is formed at each of the two end sections of the cylindrical body. The primary winding 3w and the secondary winding 5w are arranged and aligned centrally within this cylindrical body, overlapping one another in the axial direction A.

[0090] The functional element 9 is screwed into the internal thread at the end section of the rotor shaft 51 via the coupling section 9a, completely immersed. The retaining ring 11 is arranged between the functional element 9 and the secondary arrangement 5.

[0091] The support shaft 7 protrudes from the cylindrical body on both sides. The support shaft 7 is rotatably mounted on the side of the bearing seat 51c via the bearing 53 relative to the rotor shaft 51.

[0092] Fig. 4 shows several schematic cross-sectional views of further exemplary embodiments A2 to A4 for coupling the functional element 9 to the rotor shaft 51. In the exemplary embodiments A2 to A4, the coupling is positively locked. Axial securing can be achieved, for example, via an additional retaining ring and a spring (not shown).

[0093] In the embodiment A2, the functional element 9 is rotationally fixedly coupled to the rotor shaft 51 via a shaft-hub connection.

[0094] In exemplary embodiment A3, the functional element 9 is rotationally fixedly coupled to the rotor shaft 51 via a splined shaft connection. In exemplary embodiment A4, the functional element 9 is rotationally fixedly coupled to the rotor shaft 51 via a polygonal geometry. In exemplary embodiment A4, the polygonal geometry is, for example, an octagon.

[0095] Fig. 5a shows a longitudinal sectional view of a separately excited electric machine 100 according to the invention with a rotor assembly 50 according to the invention. The rotor assembly 50 is arranged within a housing assembly 80. For reasons of clarity, the housing assembly 80 is only partially shown in Fig. 5a.

[0096] The power transmission arrangement 1 according to the invention is arranged completely in the receiving area 51a of the rotor shaft 51, as shown in Fig. 3.

[0097] The rotor shaft 51 is arranged concentrically or coaxially within the rotor assembly 50. The rotor shaft 51 is arranged in a rotationally fixed manner within the rotor assembly 50. A rotor winding 57 is arranged around the rotor shaft 51. The secondary assembly 5 is electrically connected to the rotor winding 57 via the rotor connection line 21.

[0098] A tubular side member 59 is connected to the rotor shaft 51 at the front end in a rotationally fixed manner. The side member 59 has a conically tapered section. The rotor assembly 50 is rotatably mounted to the housing assembly 80 via the side member 59. The side member 59 is connected to the housing assembly 80 via a rotor bearing assembly 55.

[0099] The conductor arrangement 13 runs within the side part 59. The conductor arrangement 13 electrically connects or couples the primary arrangement 3 to a power electronics unit 90. The conductor arrangement 13 is designed to be flexible enough to compensate for axial play of the rotor arrangement 50 in the axial direction A.

[0100] Fig. 5b shows a detailed view of Fig. 5a with a fixing section 7a on the support shaft 7. The fixing section 7a is formed at an end section of the support shaft 7. The fixing section 7a protrudes from the rotor shaft 51 and the side part 59. The support shaft 7 is non-rotatably connected to the housing assembly 80 via the fixing section 7a and a securing part 81.

[0101] The power transmission arrangement according to the invention is not limited to use in the separately excited electrical machine described above. The power transmission arrangement can also be used in any other electrical machine. Further aspects and embodiments of the present invention will become apparent to those skilled in the art from the claims.

[0102] Reference symbol

[0103] Power transmission arrangement

[0104] Primary arrangement f Primary ferrite w Primary winding

[0105] Secondary arrangement f Secondary ferrite w Secondary winding

[0106] air gap

[0107] Carrier shaft a Fixing section b Cable routing

[0108] Functional element a Coupling section b Bearing seat c Force introduction area 1 Retaining ring 3 Conductor arrangement 5 Printed circuit board 7 Bearing 9 Rectifier arrangement 1 Rotor connecting cable 0 Rotor arrangement 1 Rotor shaft 1a Receptacle area 1 b Inside of the receptacle area 1c Bearing seat 3 Bearing 5 Rotor bearing arrangement 7 Rotor winding 9 Side part 80 Housing arrangement

[0109] 81 Safety part

[0110] 90 Power electronics

[0111] 100 Separately excited electrical machine

[0112] A Axial direction

[0113] R rotation axis

Claims

Patent claims 1. Power transmission arrangement (1), in particular an inductive power transmission arrangement, for transmitting power to a rotor arrangement (50) of a separately excited electrical machine (100), comprising a primary arrangement (3) and a secondary arrangement (5) for electrical power transmission, a carrier shaft (7) which is connected in a rotationally fixed manner to the primary arrangement (3) and a functional element (9), wherein the carrier shaft (7) is rotatably mounted in the functional element (9) and the functional element (9) is designed to be rotatably coupled to the rotor shaft (51) within a receiving area (51a) in a rotor shaft (51).

2. Power transmission arrangement (1) according to claim 1, wherein the functional element (9) comprises a coupling section (9a) which is designed to couple the functional element (9) to the rotor shaft (51) in a rotationally fixed manner within the receiving area (51a) in the rotor shaft (51).

3. Power transmission arrangement (1) according to claim 1 or 2, wherein the functional element (9) is disc-shaped.

4. Power transmission arrangement (1) according to one of the preceding claims, wherein a bearing seat (9b) is formed in the functional element (9), in which the support shaft (7) is rotatably mounted.

5. Power transmission arrangement (1) according to one of the preceding claims, wherein the primary arrangement (3) is arranged fixed to the secondary arrangement (5) in an axial direction (A) along a rotational axis (R) of the rotor shaft (51).

6. Power transmission arrangement (1) according to one of the preceding claims, further comprising a retaining ring (11), wherein the retaining ring (11) is arranged in the axial direction (A) between the secondary arrangement (5) and the functional element (11).

7. Power transmission arrangement (1) according to one of the preceding claims, wherein a fixing section (7a) is formed on the support shaft (7) for the rotationally fixed fixing of the support shaft (7).

8. Power transmission arrangement (1) according to one of the preceding claims, wherein a line guide (7b) for carrying a conductor arrangement (13) is formed on the carrier shaft (7).

9. Rotor arrangement (50) for a separately excited electrical machine (100), comprising a power transmission arrangement (1) according to one of the preceding claims and a hollow rotor shaft (51) arranged about a common axis of rotation (R), wherein the power transmission arrangement (1) is arranged within the receiving area (51 a) in the rotor shaft (51).

10. Rotor arrangement (50) according to claim 9, wherein the functional element (9) and the secondary arrangement (5) are coupled in a rotationally fixed manner to an inner side (51b) of the receiving area (51a).

11. Rotor arrangement (50) according to claim 9 or 10, wherein a bearing seat (51c) is formed within the rotor shaft (51) and the support shaft (7) is rotatably mounted in the bearing seat (51c) and in the functional element (9).

12. Separately excited electrical machine (100), comprising a rotor arrangement (50) according to one of claims 9 to 11, a stator arrangement and a housing arrangement (80).

13. Separately excited electrical machine (100) according to claim 12, wherein the primary arrangement (3) is electrically coupled to a power electronics system (90) via a line arrangement (13) which is flexible in the axial direction (A).

14. Separately excited electrical machine (100) according to claim 12 or 13, wherein the carrier shaft (7) is fixed in a rotationally fixed manner to the housing arrangement (80) via a fixing section (7a).

Images