TRANSMISSION FOR AN AT LEAST PARTIALLY ELECTRICALLY DRIVEN VEHICLE, AND SYNCHRONIZATION DEVICE FOR SUCH A TRANSMISSION

Abstract

A transmission for an at least partially electrically driven vehicle includes a rotor shaft of an electric machine, an input shaft, and a synchronization device arranged to couple the input shaft to the rotor shaft. The synchronization device includes a first synchronization ring connected to the rotor shaft for conjoint rotation, a second synchronization ring, a friction disk located axially between the first synchronization ring and the second synchronization ring, a clutch body connected to the input shaft for conjoint rotation, and a sliding sleeve, axially slidable along the clutch body to initiate synchronization of the first synchronization ring and the second synchronization ring for conjoint rotation to couple the rotor shaft to the input shaft. The first synchronization ring may have a cone for receiving the second synchronization ring.

Claims

1. A transmission for an at least partially electrically driven vehicle, comprising an input shaft which can be coupled to a rotor shaft of an electric machine via a synchronization device; at least one friction disk which is located axially between a first synchronization ring, which is connected to the rotor shaft for conjoint rotation, and a second synchronization ring; a clutch body which is connected to the input shaft for conjoint rotation; and a sliding sleeve which is axially slidable along the clutch body, wherein the sliding sleeve is designed to be moved axially in relation to the clutch body by an actuating element in order to initiate synchronization of the synchronization rings and establish a connection to the two synchronization rings for conjoint rotation in order to couple the rotor shaft to the input shaft.

2. The transmission according to claim 1, wherein a cone for receiving the second synchronization ring is formed on the first synchronization ring.

3. The transmission according to claim 1, wherein the first synchronization ring has an internal toothing, which meshes with an external toothing formed on the rotor shaft.

4. The transmission according to claim 1, wherein the clutch body has an internal toothing, which meshes with an external toothing formed on the input shaft.

5. The transmission according to claim 1, wherein the input shaft is mounted coaxially to the rotor shaftby means of at least two bearing elements.

6. The transmission according to claim 5, wherein the two bearing elements are designed to support the input shaft at least radially relative to a housing of the transmission.

7. The transmission according to claim 5, wherein the rotor shaft is designed to be hollow at least in sections at an end facing the input shaft in order to receive the first bearing element for mounting the input shaft.

8. The transmission according to claim 1, wherein a parking lock gear with a toothing is arranged on the input shaft, wherein the parking lock gear is designed such that a pawl for blocking a rotation of the input shaft engages with the toothing.

9. A synchronization device for a transmission for an at least partially electrically driven vehicle, which is designed to couple an input shaft of the transmission to a rotor shaft of an electric machine, comprising at least one friction disk which is located axially between a first synchronization ring and a second synchronization ring, wherein the first synchronization ring is designed to be connected to the rotor shaft for conjoint rotation, further comprising a clutch body, which is designed to be connected to the input shaft for conjoint rotation, and a sliding sleeve axially slidable along the clutch body, which can be moved axially in relation to the clutch body by an actuating element and initiates synchronization of the synchronization rings and establishes a connection to the two synchronization rings for conjoint rotation in order to couple the rotor shaft to the input shaft.

10. A vehicle comprising a synchronization device according to claim 9.

11. A transmission for an at least partially electrically driven vehicle, comprising: a rotor shaft of an electric machine; an input shaft; and a synchronization device arranged to couple the input shaft to the rotor shaft, the synchronization device comprising: a first synchronization ring connected to the rotor shaft for conjoint rotation; a second synchronization ring; a friction disk located axially between the first synchronization ring and the second synchronization ring; a clutch body connected to the input shaft for conjoint rotation; and a sliding sleeve, axially slidable along the clutch body to initiate synchronization of the first synchronization ring and the second synchronization ring for conjoint rotation to couple the rotor shaft to the input shaft.

12. The transmission of claim 11, wherein the first synchronization ring comprises a cone for receiving the second synchronization ring.

13. The transmission of claim 11, wherein: the rotor shaft comprises an external toothing; and the first synchronization ring comprises an internal toothing meshed with the external toothing.

14. The transmission of claim 11, wherein: the input shaft comprises an external toothing; and the clutch body comprises an internal toothing meshed with the external toothing.

15. The transmission of claim 11 further comprising: a first bearing element; and a second bearing element, wherein the input shaft is mounted coaxially to the rotor shaft by the first bearing element and the second bearing element.

16. The transmission of claim 15 further comprising a housing, wherein the first bearing element and the second bearing element radially support the input shaft relative to the housing.

17. The transmission of claim 15, wherein: the rotor shaft comprises a hollow section at an end facing the input shaft; and the first bearing element is disposed in the hollow section.

18. The transmission of claim 11 further comprising a parking lock gear arranged on the input shaft, wherein: the parking lock gear comprises a toothing; and the toothing is arranged to engage a pawl for blocking a rotation of the input shaft.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The disclosure is described in more detail below together with the description of two exemplary embodiments with reference to the figures. In the figures,

[0021] FIG. 1 shows a schematic view of a transmission with a synchronization device according to a first embodiment,

[0022] FIG. 2 shows a schematic exploded view of the transmission according to FIG. 1,

[0023] FIG. 3 shows a schematic exploded view of the transmission with the synchronization device according to a second embodiment, and

[0024] FIG. 4 shows a perspective sectional view of the transmission according to FIG. 3.

DETAILED DESCRIPTION

[0025] FIGS. 1 to 4 show a transmission 1 for an at least partially electrically driven vehicle, not shown here, in various embodiments in part. The transmission 1 includes a rotor shaft 4, which is operatively connected to a rotor of an electric machine, not shown here. Furthermore, the transmission 1 includes an input shaft 2, which transmits a torque and a rotational speed to an intermediate shaft, also not shown here, via an external toothing 17.

[0026] The rotor shaft 4 is rotatably mounted on a housing 10 of the transmission 1 via two bearing elements 22, 23. The input shaft 2 is also mounted coaxially to the rotor shaft 4 in relation to the housing 10 via two bearing elements 15, 16. According to a first embodiment as shown in FIGS. 1 and 2, both bearing elements 15, 16 are designed to support the input shaft 2 at least radially relative to the housing 10 of the transmission 1.

[0027] According to an alternative embodiment as shown in FIGS. 3 and 4, the rotor shaft 4 is designed to be hollow, and the input shaft 2 partially projects coaxially into the rotor shaft 4 and is supported on the rotor shaft 4 via the first bearing element 15, which is designed as a needle bearing to save radial installation space in the present case. Consequently, the rotor shaft 4 is designed to receive the first bearing element 15 for mounting the input shaft 2. The partial integration of the input shaft 2 into the interior of the rotor shaft 4 saves axial installation space of the transmission 1.

[0028] The input shaft 2 and the rotor shaft 4 can be coupled to one another via a synchronization device 3. The synchronization device 3 is configured in such a manner that, after synchronization of the rotational speeds of the input shaft 2 and the rotor shaft 4, a coupling occurs in order to transmit a torque as well as a rotational speed.

[0029] The synchronization device 3 includes a friction disk 5 which is located axially between a first synchronization ring 6 connected to the rotor shaft 4 for conjoint rotation and a second synchronization ring 7. The first synchronization ring 6 has an internal toothing 11 that meshes with an external toothing 12 formed on the rotor shaft 4. Furthermore, the synchronization device 3 has a clutch body 8 connected to the input shaft 2 for conjoint rotation, on the outer circumference of which is located a sliding sleeve 9 in an axially movable manner. The connection for conjoint rotation of the clutch body 8 to the input shaft 2 is achieved by the clutch body 8 having an internal toothing 13, which meshes with an external toothing 14 formed on the input shaft 2. The sliding sleeve 9 has an internal toothing 13, which is designed to be complementary to an external toothing 24, 25, 26 of the two synchronization rings 6, 7 and of the clutch body 8, so that a connection for conjoint rotation is provided or can be established between the components 6, 7, 8, as explained below.

[0030] In a decoupled state of the transmission 1, the sliding sleeve 9 with its internal toothing 13 exclusively meshes with the external toothing 26 of the clutch body 8, and the sliding sleeve 9 is axially movable in relation to the clutch body 8 by an actuating element, not shown here. The actuating element is designed, for example, as a shift fork, which is actuated by an actuator as a result of a driver’s request to couple the rotor shaft 4 to the input shaft 2 and as a result axially moves the sliding sleeve 9 in the direction of the synchronization rings 6, 7.

[0031] By moving the sliding sleeve 9 in the direction of the synchronization rings 6, 7, synchronization of the synchronization rings 6, 7 is initiated, whereby a first rotational speed of the first synchronization ring 6, which is connected to the rotor shaft 4 for conjoint rotation, can be matched or is matched to a second rotational speed of the second synchronization ring 7, which is connected to the input shaft 2 for conjoint rotation, until the first and second rotational speeds are substantially equal.

[0032] The synchronization of the rotational speeds is achieved by the sliding sleeve 9 first meshing with the external toothing 25 of the second synchronization ring 7 as a result of its axial movement. Subsequently, the second synchronization ring 7 is pressed in the direction of the first synchronization ring 6 by the axially moving sliding sleeve 9, wherein the friction disk 5, which is designed here as a conical friction ring, comes into frictional contact with the two synchronization rings 6, 7. The acting frictional forces match the rotational speeds of the synchronization rings 6, 7 so that the sliding sleeve 9 can then mesh with the external toothing 24 of the first synchronization ring 6 in order to couple the rotor shaft 4 to the input shaft 2. In other words, synchronization of the rotational speeds occurs first, and a coupling of the rotor shaft 4 to the input shaft 2 occurs after synchronization. A decoupling of the rotor shaft 4 from the input shaft 2, or vice versa, is done in reverse order. The axial movement of the sliding sleeve 9 for coupling or decoupling the rotor shaft 4 with/from the input shaft 2 occurs in a continuous movement, and the components of the synchronization device 3 are designed and dimensioned accordingly.

[0033] To improve the friction properties, e.g., to increase the friction surface, the first synchronization ring 6 has a cone 21, which is designed to receive the second synchronization ring 7. For this purpose, the second synchronization ring 7 has a friction surface 20 designed to be complementary to the cone 21, wherein the friction disk 5 is also designed correspondingly.

[0034] The decoupling of the rotor shaft 4 from the input shaft 2 is beneficial if, as is the case here, a parking lock gear 18 of a parking lock device, not shown further here, is arranged on the input shaft 2 for conjoint rotation. As a result of a driver’s request to activate the parking lock, a pawl, not shown here, is actuated which, as a result of the activation of the parking lock device, engages in a toothing 19 of the parking lock gear 18 designed as an external toothing, thereby blocking a rotation of the input shaft 2. To prevent the resulting torque peaks caused by interference pulses, the synchronization device decouples the rotor shaft 4 from the input shaft 2 in the manner described above so that damage to the electric machine is prevented.

[0035] The parking lock device can include a separate actuator by means of which the pawl is at least indirectly actuated. Alternatively, the transmission 1 can be designed in such a manner that both the pawl and the sliding sleeve 9 are actuated by the same actuator. Thus, by decoupling the rotor shaft 4 from the input shaft 2, in the event that the parking lock is activated, it is possible to activate the parking lock even if the vehicle is still rolling or being driven at a very low speed without damaging the electric machine.

REFERENCE NUMERALS

[0036] 1 Transmission [0037] 2 Input shaft [0038] 3 Synchronization device [0039] 4 Rotor shaft [0040] 5 Friction disk [0041] 6 First synchronization ring [0042] 7 Second synchronization ring [0043] 8 Clutch body [0044] 9 Sliding sleeve [0045] 10 Housing of the transmission [0046] 11 Internal toothing of the first synchronization ring [0047] 12 External toothing of the rotor shaft [0048] 13 Internal toothing of the clutch body [0049] 14 First external toothing of the input shaft [0050] 15 First bearing element [0051] 16 Second bearing element [0052] 17 Second external toothing of the input shaft [0053] 18 Parking lock gear [0054] 19 Toothing of the parking lock gear [0055] 20 Friction surface of the second synchronization ring [0056] 21 Cone [0057] 22 Third bearing element [0058] 23 Fourth bearing element [0059] 24 Locking toothing of the first synchronization ring [0060] 25 Locking toothing of the second synchronization ring [0061] 26 Locking toothing of the clutch body