US-12627184-B2 - Rotor assembly for an electric machine

Abstract

Proposed is a rotor assembly for an electric machine, having a rotor that comprises a laminated-core support, a rotor support and a rotor hub, the rotor support being approximately in the form of a disk and being provided with at least one circumferential annular rib portion to increase rigidity. An electric machine having a rotor assembly is also proposed. Additionally proposed are a hybrid automatic transmission and an electrically driven axle, both of which are equipped with a rotor assembly.

Inventors

• Thomas Riedisser
• Matthias Weidner
• Peter Fenn
• Florian Pöhnlein
• Claudius Flogaus

Assignees

• ZF FRIEDRICHSHAFEN AG

Dates

Publication Date

20260512

Application Date

20220503

Priority Date

20210506

Claims (17)

1. 1 . A hybrid automatic gear mechanism of a vehicle comprising: a rotor arrangement for an electric machine, the rotor arrangement comprising: a rotor which comprises a metal sheet assembly carrier and a rotor carrier and a rotor hub, wherein the rotor carrier is substantially disk-like and has at least one circumferential annular rib portion configured to increase rigidity; and a housing having therein: at least one electric machine arranged coaxially relative to a centrally arranged gear mechanism shaft; and a plate switching element arranged radially inside a rotor of the electric machine, wherein the rotor carrier of the rotor is arranged axially between a plate carrier of the plate switching element and a pre-transmission in the housing, and wherein the annular rib portion of the rotor carrier is arranged in a state radially nested in a formation of the plate carrier.
2. 2 . The hybrid automatic gear mechanism according to claim 1 , wherein the annular rib portion is provided over an entire circumference and protrudes in an axial direction on the rotor carrier.
3. 3 . The hybrid automatic gear mechanism according to claim 2 , wherein the annular rib portion is arranged, when viewed radially between the metal sheet assembly carrier and the rotor hub, on the rotor carrier.
4. 4 . The hybrid automatic gear mechanism according to claim 2 , wherein the annular rib portion comprises a U-shaped formation.
5. 5 . The hybrid automatic gear mechanism according to claim 2 , wherein the annular rib portion is provided as a materially reinforced region by means of forging.
6. 6 . The hybrid automatic gear mechanism according to claim 2 , wherein the annular rib portion is provided as a separate component on the rotor carrier.
7. 7 . The hybrid automatic gear mechanism according to claim 1 , wherein the annular rib portion is arranged, when viewed radially between the metal sheet assembly carrier and the rotor hub, on the rotor carrier.
8. 8 . The hybrid automatic gear mechanism according to claim 7 , wherein the annular rib portion comprises a U-shaped formation.
9. 9 . The hybrid automatic gear mechanism according to claim 7 , wherein the annular rib portion is provided as a materially reinforced region by means of forging.
10. 10 . The hybrid automatic gear mechanism according to claim 7 , wherein the annular rib portion is provided as a separate component on the rotor carrier.
11. 11 . The hybrid automatic gear mechanism according to claim 1 , wherein the annular rib portion comprises a U-shaped formation.
12. 12 . The hybrid automatic gear mechanism according to claim 11 , wherein the annular rib portion is provided as a materially reinforced region by means of forging.
13. 13 . The hybrid automatic gear mechanism according to claim 11 , wherein the annular rib portion is provided as a separate component on the rotor carrier.
14. 14 . The hybrid automatic gear mechanism according to claim 1 , wherein the annular rib portion is provided as a materially reinforced region by means of forging.
15. 15 . The hybrid automatic gear mechanism according to claim 14 , wherein the annular rib portion is provided as a separate component on the rotor carrier.
16. 16 . The hybrid automatic gear mechanism according to claim 1 , wherein the annular rib portion is provided as a separate component on the rotor carrier.
17. 17 . An electrically driven vehicle comprising the hybrid automatic gear mechanism according to claim 1 .

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a U.S. national stage application under 35 U.S.C. § 371 of PCT Application No. PCT/EP2022/061808, filed on May 3, 2022, and published as WO 2022/233845 A1 on Nov. 10, 2022, which claims priority from German Application No. DE 10 2021 204 575.8, filed on May 6, 2021, the entirety of which are each hereby fully incorporated by reference herein. The present invention relates to a rotor arrangement for an electric machine according to the type defined in greater detail in the preamble of patent claim 1. The invention further relates to an electric machine having a rotor arrangement and a hybrid automatic gear mechanism of a vehicle and an electrically driven axle of a vehicle having a rotor arrangement in each case. Document DE 10 2016 211 940 A1 discloses, for example, a hybrid drive module for a motor vehicle drive train having an electric machine in a housing of a hybrid automatic gear mechanism. The electric machine is arranged coaxially relative to a central gear mechanism shaft, wherein a plate switching element is provided radially inside a metal sheet assembly carrier of a rotor of the electric machine. The metal sheet assembly carrier is rotatably supported on the central gear mechanism shaft by means of a rotor carrier and a rotor hub. In order to optimize the efficiency of the electric machine, the smallest possible air gap is provided between the stator and the rotor of the electric machine in order to thereby bring about a positive effect on the degree of efficiency of the electric machine since the losses increase as the air gap increases. With a decreasing air gap, however, the static magnetic force with which the permanent magnets in the metal sheet assembly carrier of the rotor are attracted to the stator also increases. With ideal coaxiality theoretically over 360°, these static magnetic forces are identical and opposed in terms of their vector magnitude and therefore balanced in terms of force. However, as soon as the rotor is displaced from the center relative to the stator and the air gap consequently becomes unequal, the magnetic forces increase at the narrow location and decrease at the location with the larger air gap. This effect leads to a single-sided radial loading of the rotor. Consequently, a curvature or a bend is produced on the disk-like rotor carrier. This axial curvature of the planar face on the rotor carrier leads to a radial inclination of the entire rotor within the air gap. For this reason, the rotor carrier is accordingly generally configured to be thick-walled or solid. However, this leads to considerable additional weight and additional costs and to an undesirably high structural space requirement. An object of the present invention is to provide a rotor arrangement and an electric machine and a hybrid automatic gear mechanism and an electric drive axle which provide a configuration of a rotor carrier which is optimized in terms of rigidity for increasing the degree of efficiency with the lowest possible production costs and lowest possible structural space requirement. This object is achieved according to the invention by the features of patent claims 1 and 7 or 8 and 10. Advantageous and claimed further developments will be appreciated from the respective dependent claims and the description and the drawings. Consequently, a rotor arrangement for an electric machine having a rotor which comprises a metal sheet assembly carrier and a rotor carrier and a rotor hub is proposed. In order in particular to achieve a configuration of the rotor carrier which is optimized in terms of rigidity, there is provision for the substantially disk-like rotor carrier to have at least one circumferential annular rib portion or an annular rib in order to increase rigidity. With the proposed rotor arrangement, as a result of the annular rib portion provided, there is brought about a clear stiffening of the planar face or the disk-ring-like region of the rotor carrier. The effect of the annular rib portion reduces the curvature of the entire disk-like rotor carrier as a result of the high level of annular rigidity of the annular rib portion since a torsion resulting from the ring closure and the build-up of tension/compression stresses is not permitted. The axial curvature of the rotor carrier is also thereby reduced, which consequently also prevents a radial inclination of the entire rotor with respect to the stator which is fixed to the housing. In the context of the invention, there is provision for the annular rib portion to be provided over the entire circumference and so as to protrude in an axial direction on the rotor carrier. The annular rib portion consequently produces virtually a 360° circumferential geometric element, which is as far as possible axially elongate and at the same time has a relatively small radial height. The arrangement position of the annular rib portion on the rotor carrier is determined at locations