Transmission

Abstract

A transmission for a motor vehicle includes an electric motor. A rotor shaft is connected in a torque-proof manner to a rotor of the electric motor. At least one bearing directly supports the rotor shaft. A transmission shaft is connected in a torque-proof manner to the rotor shaft. Both the transmission shaft and the rotor shaft are supported directly on a transmission component by the at least one bearing.

Claims

1. A transmission for a motor vehicle, comprising: an electric motor having a rotor; a rotor shaft connected in a torque-proof manner to the rotor of the electric motor; at least one bearing that directly supports the rotor shaft; a transmission shaft connected in a torque-proof manner to the rotor shaft; a groove nut threaded onto the transmission shaft for preloading the at least one bearing; a multi-speed transmission gearing in operative connection with the transmission shaft; and an output shaft in operative connection with the transmission shaft by the transmission gearing; wherein both the transmission shaft and the rotor shaft are supported directly on a transmission component by the at least one bearing.

2. The transmission of claim 1, further comprising an input shaft coupleable to an internal combustion engine, the input shaft connectable to the rotor shaft in a torque-proof manner by a shift element.

3. The transmission of claim 1, further comprising a retainer for retaining the electric motor, the transmission shaft and the rotor shaft supportable on the retainer by the at least one bearing.

4. The transmission of claim 3, wherein the transmission shaft is connected in a torque-proof manner to the rotor shaft by a positive-locking connection.

5. The transmission of claim 4, the at least one bearing is arranged radially between a section of the retainer and a section of the rotor shaft.

6. The transmission of claim 1, wherein the transmission shaft is supported on a transmission housing directly or through the output shaft by an additional bearing.

7. A hybrid drive comprising the transmission of claim 1, wherein an internal combustion engine is coupled with an input shaft, the input shaft connectable to the rotor shaft in a torque-proof manner by a shift element.

8. A motor vehicle comprising the hybrid drive of claim 7.

9. A motor vehicle comprising the transmission of claim 1.

10. A transmission for a motor vehicle, comprising: an electric motor having a rotor; a rotor shaft connected in a torque-proof manner to the rotor of the electric motor; at least one bearing that directly supports the rotor shaft; a transmission shaft connected in a torque-proof manner to the rotor shaft; a multi-speed transmission gearing in operative connection with the transmission shaft; and an output shaft in operative connection with the transmission shaft by the transmission gearing; wherein both the transmission shaft and the rotor shaft are supported directly on a transmission component by the at least one bearing, and wherein the at least one bearing is supported in an axial direction on one side of the at least one bearing on the rotor shaft and on another side of the at least one bearing on a shoulder of the transmission shaft.

11. A transmission for a motor vehicle, comprising: an electric motor having a rotor; a rotor shaft connected in a torque-proof manner to the rotor of the electric motor; at least one bearing that directly supports the rotor shaft; a transmission shaft connected in a torque-proof manner to the rotor shaft; a multi-speed transmission gearing in operative connection with the transmission shaft; and an output shaft in operative connection with the transmission shaft by the transmission gearing; wherein both the transmission shaft and the rotor shaft are supported directly on a transmission component by the at least one bearing, wherein the at least one bearing comprises at least one rolling bearing that is configured to absorb forces in an axial direction and a radial direction, and wherein: the at least one rolling bearing comprises a double-row angular ball bearing; or the at least one rolling bearing comprises a first single-row angular ball bearing and a second single-row angular ball bearing with an adjuster arranged between the first single-row angular ball bearing and the second single-row angular ball bearing.

12. A transmission for a motor vehicle, comprising: an electric motor having a rotor; a rotor shaft connected in a torque-proof manner to the rotor of the electric motor; at least one bearing that directly supports the rotor shaft; a transmission shaft connected in a torque-proof manner to the rotor shaft; a multi-speed transmission gearing in operative connection with the transmission shaft; and an output shaft in operative connection with the transmission shaft by the transmission gearing; wherein both the transmission shaft and the rotor shaft are supported directly on a transmission component by the at least one bearing, and wherein the at least one bearing comprises a first radial slide bearing and a second radial slide bearing.

13. The transmission of claim 12, wherein the at least one bearing comprises at least one axial bearing.

14. A transmission for a motor vehicle, comprising: an electric motor having a rotor; a rotor shaft connected in a torque-proof manner to the rotor of the electric motor; at least one bearing that directly supports the rotor shaft; a transmission shaft connected in a torque-proof manner to the rotor shaft; a multi-speed transmission gearing in operative connection with the transmission shaft; and an output shaft in operative connection with the transmission shaft by the transmission gearing; wherein both the transmission shaft and the rotor shaft are supported directly on a transmission component by the at least one bearing, wherein the at least one bearing comprises a first radial slide bearing and a second radial slide bearing, and wherein the transmission shaft is connected in a torque-proof manner to the rotor shaft by a positive-locking connection, the positive-locking connection of the rotor shaft and the transmission shaft arranged at least partially between the first and second radial slide bearings.

15. A transmission for a motor vehicle, comprising: an electric motor having a rotor; a rotor shaft connected in a torque-proof manner to the rotor of the electric motor; at least one bearing that directly supports the rotor shaft; a transmission shaft connected in a torque-proof manner to the rotor shaft; a multi-speed transmission gearing in operative connection with the transmission shaft; and an output shaft in operative connection with the transmission shaft by the transmission gearing; wherein both the transmission shaft and the rotor shaft are supported directly on a transmission component by the at least one bearing, and wherein the transmission shaft is centered on the rotor shaft by a fitting, the transmission shaft is connected to the rotor shaft with a spline connection, and the fitting is separate from the spline connection between the transmission shaft and the rotor shaft.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The subject matter of the invention is shown schematically in the figures and is described below, whereas the same or equivalent elements are usually provided with the same reference signs. The following are shown:

(2) FIG. 1 a schematic view of a first embodiment of the transmission in accordance with exemplary aspects of the invention for a motor vehicle;

(3) FIG. 2 an enlarged section of the transmission in accordance with exemplary aspects of the invention for a motor vehicle in accordance with a second embodiment;

(4) FIG. 3 an enlarged section of the transmission in accordance with exemplary aspects of the invention for a motor vehicle in accordance with a third embodiment; and

(5) FIG. 4 an enlarged section of the transmission in accordance with exemplary aspects of the invention for a motor vehicle in accordance with a fourth embodiment.

DETAILED DESCRIPTION

(6) Reference will now be made to embodiments of the invention, one or more examples of which are shown in the drawings. Each embodiment is provided by way of explanation of the invention, and not as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be combined with another embodiment to yield still another embodiment. It is intended that the present invention include these and other modifications and variations to the embodiments described herein.

(7) The transmission for a motor vehicle shown in FIG. 1 features an electric motor EM that is coupled in a torque-proof manner to a rotor shaft 3, and a bearing 4 that directly supports the rotor shaft 3. In addition, the transmission features a transmission shaft 5, which is connected in a torque-proof manner to the rotor shaft 3. The transmission shaft 5 is in operative connection with a multi-speed transmission gearing 6. In addition, the transmission features an output shaft 7, which is in operative connection with the transmission shaft 5 by the transmission gearing 6. Both the transmission shaft 5 and the rotor shaft 3 are supported on a transmission component described in more detail below by the bearing 4.

(8) In the version shown in FIG. 1, the transmission component corresponds to a retainer 8, which serves to retain a stator 1 of the electric motor EM. The retainer 8 is detachably connected (in particular, screwed) to an intermediate housing 9. The intermediate housing 9 is connected in a torque-proof manner (in particular, screwed) to a transmission housing 19. The intermediate housing 9 features lines through which the individual components of the transmission can be supplied with fluid, in particular oil. In particular, the fluid can be fed to an actuating device 14, which is discussed further below. The electric motor EM features, in addition to the stator 1, a rotor 2 that is connected to the rotor shaft 3 in a torque-proof manner.

(9) The bearing 4 is a double-row angular ball bearing in an O-arrangement, and is arranged in the radial direction between the rotor shaft 3 and the retainer 8. In this case, the bearing 4 is in direct contact with the rotor shaft 3 and the transmission shaft 5. In particular, an inner ring of the double-row angular ball bearing is attached to both the rotor shaft 3 and the transmission shaft 5. The inner ring is fixed in its axial position by the transmission shaft 5 and the rotor shaft 3, such that a relative movement between the inner ring and the rotor shaft 3 and/or the transmission shaft 5 is not possible. In particular, the inner ring abuts against a shoulder 10 of the transmission shaft 5 on one side. On an opposite side of the inner ring, the inner ring abuts against a section of the rotor shaft 3 projecting in the radial direction.

(10) An outer ring of the double-row angular ball bearing is in direct contact with the retainer 8. The outer ring of the double-row angular ball bearing is fixed in its axial position by the retainer 8. This means that the outer ring cannot move in the axial direction relative to the retainer 8.

(11) The rotor shaft 3 is connected in a torque-proof manner to the transmission shaft 5 by a spline. Thereby, the bearing 4 is arranged on a section of the rotor shaft 4, which features the internally toothed hub of the spline.

(12) The transmission features a clamping device in the form of a groove nut 11. The groove nut 11 is screwed onto the drive shaft 5 and exerts an axial force on the rotor shaft 3 and thus the bearing 4. In particular, as a result of the force exerted by the groove nut 11, the bearing 4 is pressed against the shoulder 10 of the transmission shaft 5.

(13) In addition, the transmission features an input shaft 12, which is coupled to an internal combustion engine VM, and a shift element 13 in the form of a clutch. The input shaft 12 is connectable in a torque-proof manner to the rotor shaft 3 by the shift element 13.

(14) An actuation of the shift element 13 can take place by an actuating device 14, which can be, for example, a release bearing. In doing so, the actuating device 14 exerts an axial force for closing the shift element 13 on it. A lever 16 of the actuating device, through which the shift element 13 is actuated, extends through the rotor shaft 3. In addition, the actuating device 14 features a piston 23 that is coupled to the lever 16, which piston, upon the actuation of the actuating device 14, is subjected to a fluid and consequently moves in the axial direction. As a result of the axial movement of the piston, the lever 16 presses against the shift element 13 and thus exerts the axial force on the shift element 13.

(15) The transmission gearing features a multiple number of planetary gear sets and shift elements, by which different gears can be realized with different transmission ratios.

(16) The transmission shaft 5 is supported next to the bearing 4 by an additional bearing 15. The additional bearing 15 is arranged on the output shaft 7 and supports the output shaft 7 directly on the transmission housing 19.

(17) FIG. 2 shows an enlarged section of the transmission in accordance with exemplary aspects of the invention for a motor vehicle in accordance with a second embodiment. The embodiment shown in FIG. 2 differs from the embodiment shown in FIG. 1 in the formation of the bearing 4.

(18) Thus, the second embodiment shown in FIG. 2 features two single-row angular ball bearings in an O-arrangement. The two single-row angular ball bearings are arranged in a manner spaced apart in the axial direction. An adjusting disk 17 is arranged between the two angular ball bearings. The adjusting disk 17 is in direct contact with the inner rings of the two angular ball bearings.

(19) The two angular ball bearings are preloaded by the groove nut 11. In particular, an axial force exerted by the groove nut 11 is transferred through the rotor shaft 3, a first angular ball bearing, the adjusting disk 17 to the second angular ball bearing, by which the second angular ball bearing is pressed against the shoulder 10 of the transmission shaft 3.

(20) In addition, there is a difference with the embodiment shown in FIG. 1 in that only one inner ring of the angular ball bearing located further away from the input shaft and/or internal combustion engine is arranged both on the transmission shaft 5 and on the rotor shaft 3.

(21) FIG. 3 shows an enlarged section of the transmission in accordance with exemplary aspects of the invention for a motor vehicle in accordance with a third embodiment. The third embodiment differs from the second embodiment in the formation of a larger bearing base.

(22) FIG. 4 shows an enlarged section of the transmission in accordance with exemplary aspects of the invention for a motor vehicle in accordance with a fourth embodiment. With the embodiment shown in FIG. 4, a first slide bearing 24 and a second slide bearing 25 are present, by which the rotor shaft 3 and the transmission shaft 5 are supported on the retainer 8. The rotor shaft 3 is directly supported on the retainer 8 by the first and second slide bearings 24, 25. The two slide bearings 24, 25 are able to absorb radial forces exclusively. In addition, two axial bearings 21, 22, which absorb exclusively axial forces, are provided.

(23) In addition to the plug connection, the rotor shaft 3 is centered on the transmission shaft 5 by a fitting. The fitting is arranged in an area of the transmission shaft 5, which is turned away from the internal combustion engine VM in the axial direction further than the plug connection. In particular, the fitting takes place in the area of the two axial bearings 21, 22.

(24) The plug connection and the fitting support the transmission shaft 5 in the radial direction on the rotor shaft 3. This means that, in this version, the transmission shaft 5 is supported on the retainer 8 by the plug-in connection and the fitting, the rotor shaft 3 and the first and second slide bearings 24, 25.

(25) The two axial bearings 21, 22 serve to absorb the axial forces acting on the transmission shaft 5, and are formed as axial needle bearings. Thereby, a first axial bearing 21 absorbs an axial force of the transmission shaft 5 in a first axial direction. This axial force can arise, for example, if the shift element 13 is actuated. A second bearing 22 absorbs an axial force in a second direction opposite to the first axial direction. This axial force can arise if, for example, one or more shift elements present in the transmission gearing 6 is closed.

(26) Thereby, the axial force acting on the transmission shaft 5 is transferred to the first and/or second axial bearing 21, 22 through a transfer element 20. The transfer element 20 is arranged in the axial direction between the two axial bearings 21, 22 and is in operative connection with the transmission shaft 5. Thereby, the transfer element 20 is arranged free of backlash on the transmission shaft 5. In addition, the transfer element is in direct contact with the two axial bearings 21, 22 and the transmission shaft 5.

(27) Modifications and variations can be made to the embodiments illustrated or described herein without departing from the scope and spirit of the invention as set forth in the appended claims.

REFERENCE SIGNS

(28) 1 Stator

(29) 2 Rotor

(30) 3 Rotor shaft

(31) 4 Bearing

(32) 5 Transmission shaft

(33) 6 Transmission gearing

(34) 7 Output shaft

(35) 8 Retainer

(36) 9 Intermediate housing

(37) 10 Shoulder

(38) 11 Groove nut

(39) 12 Input shaft

(40) 13 Shift element

(41) 14 Actuating device

(42) 15 Additional bearing

(43) 16 Lever

(44) 17 Adjusting disk

(45) 19 Transmission housing

(46) 20 Transfer element

(47) 21 First axial bearing

(48) 22 Second axial bearing

(49) 23 Piston

(50) 24 First slide bearing

(51) 25 Second slide bearing

(52) EM Electric motor

(53) VM Internal combustion engine