Transmission for an at least partially electrically driven vehicle and synchronization device for such a transmission

Abstract

The invention relates to a transmission (1) for an at least partially electrically driven vehicle, comprising: an input shaft (2) which can be coupled to a rotor shaft (4) of an electric machine via a synchronizing device (3); at least one friction disc (5) which is axially located between a first synchronizing ring (6) and a second synchronizing ring (7), the first synchronizing ring being connected to the rotor shaft (4) for co-rotation; a clutch body (8) which is connected to the input shaft (2) for co-rotation; and a sliding sleeve (9) which can slide axially along the clutch body (8), wherein the sliding sleeve (9) is designed to be axially moved relative to the clutch body (8) by an actuating element in order to initiate synchronization of the synchronizing ring (7) and to establish a co-rotation connection with both synchronizing rings (6, 7), thereby coupling the rotor shaft (4) to the input shaft (2). The invention also relates to a synchronizing device (3) and a vehicle having such a transmission (1) or such a synchronizing device (3).

Description

Technical Field

[0001] The invention relates to a transmission for an at least partially electrically driven vehicle and a synchronization device for such a transmission. The invention also relates to a vehicle having such a transmission and / or such a synchronization device. Background Art

[0002] During various driving maneuvers or technical procedures, pulse-like load changes can occur in the drivetrain, which can cause overloads in the drivetrain. Pulse-like load changes in the drivetrain of a motor vehicle can be described as both wheel-side shocks and load peaks caused by the drivetrain. These interference pulses occur particularly as a result of driving maneuvers, for example, through changes in wheel contact forces or sudden changes in friction conditions between the wheels and the road surface. Furthermore, interference pulses can occur when the parking lock on a vehicle is activated, leading to sudden braking of the vehicle. The resulting torque peaks lead to high loads in the drivetrain, which can also cause damage.

[0003] DE 314 83 38 A1 discloses a torsional vibration damper for transmission applications, wherein a clutch portion is arranged between a first rotating component and a second rotating component. A friction clutch in the form of a wet clutch is provided between the clutch portion and the second rotating component. The clutch portion is preloaded by a spring. A hydraulic oil chamber is provided, which changes its volume when the clutch portion moves. Summary of the Invention

[0004] The present invention is based on the further development of a transmission for an at least partially electrically driven vehicle and a synchronization device for such a transmission so that overloading and damage to drivetrain components, in particular the vehicle's electric motor, caused by interference pulses is prevented. This object is achieved by a transmission and a synchronization device having the following features. Preferred or advantageous embodiments of the invention are apparent from the following description and the accompanying drawings.

[0005] A transmission according to the present invention for an at least partially electrically driven vehicle comprises: an input shaft that can be coupled to a rotor shaft of an electric machine via a synchronizing device; at least one friction disk axially located between a first synchronizing ring and a second synchronizing ring, the first synchronizing ring being connected to the rotor shaft for common rotation; a clutch body connected to the input shaft for common rotation; and a sliding sleeve that can slide axially along the clutch body, wherein the sliding sleeve is designed to be axially moved relative to the clutch body by an actuating element to initiate synchronization of the synchronizing rings and establish a connection with the two synchronizing rings for common rotation, thereby coupling the rotor shaft to the input shaft.

[0006] By actuating and axially displacing the sliding sleeve in the direction of the first synchronizer ring, the second synchronizer ring is pressed in the direction of the first synchronizer ring, causing frictional contact between the respective friction disks of the two synchronizer rings and thereby matching the rotational speeds of the rotor shaft and the input shaft. The synchronizer device may include one or more friction disks as required, wherein the respective friction disks are provided in particular for matching the rotational speeds of the two synchronizer rings to one another, so that axial movement of the sliding sleeve onto the synchronizer ring, in particular onto the first synchronizer ring connected for co-rotation with the rotor shaft, can be performed to produce a co-rotational connection between the rotor shaft and the input shaft.

[0007] The sliding sleeve is arranged radially outside the clutch body and is axially movable relative to the clutch body. Both the clutch body and the synchronizer ring have external toothing, with the sliding sleeve having internal toothing designed to complement the external toothing. Synchronization is initiated by actuating the sliding sleeve and, before synchronization, pushing its internal toothing axially along the clutch body onto the external toothing of the second synchronizer ring. This creates a positive fit between the clutch body, the sliding sleeve, and the second synchronizer ring, all connected for co-rotation with the input shaft. After synchronization, when the two synchronizer rings rotate at the same speed, the sliding sleeve is further moved axially until it engages with the external toothing of the first synchronizer ring. This creates a positive fit between the clutch body, the sliding sleeve, and the second synchronizer ring, all connected for co-rotation with the input shaft, and the first synchronizer ring, all connected for co-rotation with the rotor shaft. The external toothing on the synchronizer ring thus acts as a locking toothing, preventing the synchronizer ring from rotating. Furthermore, the corresponding external toothing of the synchronizer ring can be designed in a roof-like shape to prevent sudden engagement with the internal toothing of the sliding sleeve.

[0008] The sliding sleeve can be moved in the axial direction by an actuating element, wherein the sliding sleeve is arranged in a transmission for co-rotation. The actuating element is designed, for example, as an actuating fork or as a screw driver, which is drivingly connected to the sliding sleeve and can be actuated by an actuator, in particular an electric motor.

[0009] Preferably, a cone is formed on the first synchronizer ring for receiving the second synchronizer ring. In this regard, the second synchronizer ring has friction surfaces designed to be complementary, with the friction disk being spatially arranged between the first and second synchronizer rings. The sliding sleeve is first pushed or screwed onto the second synchronizer ring by actuating the sliding sleeve. As a result, the second synchronizer ring is moved or pressed in the direction of the first synchronizer ring, with the friction disk arranged between the synchronizer rings pressing axially against the corresponding friction surface of the first or second synchronizer ring, so that the rotational speed of the second synchronizer ring matches that of the first, depending on the pressure. Only after the synchronizer rings have been synchronized is the rotor shaft coupled to the input shaft, or vice versa, with the sliding sleeve being pushed or screwed onto the first synchronizer ring. This ensures that synchronization occurs first, followed by coupling. This allows for precise adjustment of the locking or clutch function.

[0010] The first synchronizer ring preferably has internal teeth that mesh with external teeth formed on the rotor shaft. Furthermore, the clutch body preferably has internal teeth that mesh with external teeth formed on the input shaft. These meshing teeth ensure a secure connection, allowing for co-rotation between the rotor shaft and the first synchronizer ring, or between the input shaft and the clutch body. Furthermore, since the first synchronizer ring or the clutch body can be easily assembled and disassembled, assembly and maintenance are simplified.

[0011] According to an exemplary embodiment, the input shaft is coaxially mounted to the rotor shaft by means of at least two bearing elements. The input shaft is thus supported at least radially and preferably also axially relative to the transmission housing of the transmission. In this sense, the two bearing elements are preferably designed to support the input shaft at least radially relative to the transmission housing. The rotor shaft is also supported radially and, if necessary, axially relative to the transmission housing at at least two points via corresponding bearing elements.

[0012] According to another exemplary embodiment, the rotor shaft is designed to be at least partially hollow at the end facing the input shaft to accommodate a first bearing element for mounting the input shaft. In other words, the input shaft partially protrudes into the at least partially hollow rotor shaft and is coaxially mounted to the rotor shaft via a bearing element, which can be designed as a needle roller bearing to save radial installation space. This arrangement and design of the input and rotor shafts offers the advantage of significantly saving axial installation space in the transmission.

[0013] Preferably, a parking lock gear with teeth is arranged on the input shaft, wherein the parking lock gear is designed so that a pawl, which is used to prevent the input shaft from rotating, engages with the teeth. The parking lock gear is part of a parking lock device, which is designed to engage with the teeth of the parking lock gear. The parking lock gear is connected to the input shaft so as to rotate together with the pawl when actuated by the vehicle driver. This engagement of the pawl prevents the input shaft of the transmission from rotating and thus prevents the vehicle from rolling away. The teeth of the parking lock gear are preferably formed on the circumferential surface of the parking lock gear and thus constitute external teeth. The pawl is at least indirectly driven by the actuator.

[0014] Furthermore, at least one additional external toothing may be formed on the input shaft so that the intermediate shaft can at least indirectly mesh with the input shaft.Preventing rotation of the input shaft by means of the parking lock also prevents rotation of the intermediate shaft and components operatively connected to the intermediate shaft.

[0015] The synchronization device can be activated, for example, when the vehicle driver transmits a request to activate the parking lock device. In this case, after receiving the driver's request, the input shaft is first decoupled from the rotor shaft before the pawl of the parking lock device engages the teeth of the parking lock gear. This prevents shocks on the rotor shaft and overload and / or damage to the electric motor.

[0016] A synchronizing device for a transmission according to the present invention is designed to couple an input shaft of the transmission to a rotor shaft of an electric machine, the transmission being used in an at least partially electrically driven vehicle, wherein the synchronizing device comprises at least one friction disk, the at least one friction disk being axially located between a first synchronizing ring and a second synchronizing ring, wherein the first synchronizing ring is designed to be connected to the rotor shaft for common rotation, wherein the synchronizing device further comprises a clutch body, which is designed to be connected to the input shaft for common rotation, and wherein the synchronizing device comprises a sliding sleeve that can slide axially along the clutch body, wherein the sliding sleeve can be axially moved relative to the clutch body by an actuating element, and activates synchronization of the synchronizing rings and establishes a connection with the two synchronizing rings for common rotation, thereby coupling the rotor shaft to the input shaft.

[0017] The synchronizer is arranged in the power flow between a rotor shaft, which is at least indirectly operatively connected to the rotor of the electric machine, and an input shaft of the transmission. The synchronizer is designed to couple the rotor shaft and the input shaft to one another or to decouple the rotor shaft and the input shaft from one another, depending on the vehicle's operating state and / or at the driver's request. For example, when a parking lock is activated, the synchronizer is used to decouple the rotor shaft from the input shaft to protect the electric machine from damage caused by torque peaks, interference pulses, and shocks in the drive train.

[0018] The vehicle according to the present invention has a plurality of axles, at least one of which is drivable. The drive is at least partially electric, and the drive can also be provided by an internal combustion engine. The corresponding driven axles are connected to the drive train of the vehicle, which has a transmission according to the present invention. In particular, the vehicle has a synchronization device according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Further measures for improving the invention are described in more detail below together with the description of two preferred exemplary embodiments of the invention with reference to the accompanying drawings.

[0020] Figure 1 shows a schematic diagram of a transmission according to the invention, which has a synchronization device according to the invention according to a first embodiment,

[0021] Figure 2 Shown according to Figure 1 A schematic exploded view of the transmission according to the present invention,

[0022] Figure 3 shows a schematic exploded view of a transmission according to the invention having a synchronization device according to the invention according to a second embodiment, and

[0023] Figure 4 Shown according to Figure 3 A three-dimensional sectional view of a transmission device according to the present invention. DETAILED DESCRIPTION

[0024] Figures 1 to 4 A transmission 1 for an at least partially electrically driven vehicle (not shown here) is partially shown in various embodiments. The transmission 1 includes a rotor shaft 4, which is operatively connected to the rotor of an electric machine (not shown here). The transmission 1 also includes an input shaft 2, which transmits torque and rotational speed via an external toothing 17 to an intermediate shaft (also not shown here).

[0025] The rotor shaft 4 is rotatably mounted on the housing 10 of the transmission 1 via two bearing elements 22, 23. The input shaft 2 is also coaxially mounted to the rotor shaft 4 relative to the housing 10 via two bearing elements 15, 16. Figure 1 and Figure 2 In the first embodiment shown in FIG, 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 .

[0026] According to Figure 3 and Figure 4In the alternative embodiment shown in FIG, the rotor shaft 4 is designed to be hollow, wherein the input shaft 2 partially protrudes coaxially into the rotor shaft 4 and is supported on the rotor shaft 4 via a first bearing element 15, which is designed as a needle bearing to save radial installation space in the previous case. Therefore, 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 advantageously saves axial installation space in the transmission 1.

[0027] The input shaft 2 and the rotor shaft 4 may be coupled to each other via a synchronizer 3 , wherein the synchronizer 3 is configured such that coupling occurs after the rotational speeds of the input shaft 2 and the rotor shaft 4 are synchronized to transmit torque as well as rotational speed.

[0028] The synchronizer 3 includes a friction disk 5, which is axially positioned between a second synchronizer ring 7 and a first synchronizer ring 6 connected for co-rotation with the rotor shaft 4. The first synchronizer ring 6 has an internal toothing 11 that meshes with an external toothing 12 formed on the rotor shaft 4. Furthermore, the synchronizer 3 includes a clutch body 8, which is connected for co-rotation with the input shaft 2 and has an axially displaceable sliding sleeve 9 positioned on its outer circumference. The co-rotational connection between the clutch body 8 and the input shaft 2 is achieved by the clutch body 8 having an internal toothing 13 that meshes with an external toothing 14 formed on the input shaft 2.

[0029] The sliding sleeve 9 has an internal toothing 13 which is designed complementary to the external toothing 24 , 25 of the two synchronizer rings 6 , 7 and the external toothing 26 of the clutch body 8 , so that a connection for common rotation between the components 6 , 7 , 8 is provided or can be established, as explained below.

[0030] In the decoupled state of the transmission 1, the internal toothing 13 of the sliding sleeve 9 is fully meshed with the external toothing 26 of the clutch body 8, wherein the sliding sleeve 9 can be moved axially relative to the clutch body 8 by means of an actuating element (not shown here). The actuating element is particularly designed as a shift fork, which is actuated by an actuator in response to a driver's request to couple the rotor shaft 4 to the input shaft 2 and thus to move the sliding sleeve 9 axially in the direction of the synchronizer rings 6, 7.

[0031] Synchronization of the synchronizer rings 6 , 7 is enabled by moving the sliding sleeve 9 in the direction of the synchronizer rings 6 , 7 , whereby a first rotational speed of the first synchronizer ring 6 connected for common rotation with the rotor shaft 4 can be matched with a second rotational speed of the second synchronizer ring 7 connected for common rotation with the input shaft 2 , or vice versa, until the first and second rotational speeds are substantially equal.

[0032] Rotational speed synchronization is achieved by first engaging the external toothing 25 of the second synchronizer ring 7 due to its axial movement. Subsequently, the second synchronizer ring 7 is pressed toward the first synchronizer ring 6 by the axially displaced sliding sleeve 9, causing the friction disk 8, designed here as a conical friction ring, to come into frictional contact with both synchronizer rings 6 and 7. The resulting friction force is matched to the rotational speeds of the synchronizer rings 6 and 7, allowing the sliding sleeve 9 to then engage the external toothing 24 of the first synchronizer ring 6, coupling the rotor shaft 4 to the input shaft 2. In other words, rotational speed synchronization occurs first, followed by coupling the rotor shaft 4 to the input shaft 2. Decoupling the rotor shaft 4 from the input shaft 2, or vice versa, is accomplished in the reverse order. The axial movement of the sliding sleeve 9 for coupling or decoupling the rotor shaft 4 from the input shaft 2 occurs in a continuous motion, with the components of the synchronizer device 3 designed and dimensioned accordingly.

[0033] In order to improve the friction properties, in particular to increase the friction surface, the first synchronizer ring 6 has a cone 21 designed to receive the second synchronizer ring 7. For this purpose, the second synchronizer ring 7 has a friction surface 20 designed to complement the cone 21, wherein the friction disk 5 is also designed accordingly.

[0034] Decoupling the rotor shaft 4 from the input shaft 2 is particularly advantageous if, as is the case here, the parking lock gear 18 of a parking lock device (not shown here) is arranged for co-rotation with the input shaft 2. Due to the driver's request to activate the parking lock, a pawl (not shown here) is actuated. Due to the activation of the parking lock device, the pawl engages in the toothing 19 of the parking lock gear 18, which is designed as an external toothing, thereby blocking rotation of the input shaft 2. To prevent torque peaks caused by interference pulses, the synchronizer decouples the rotor shaft 4 from the input shaft 2 in the manner described above, thereby preventing damage to the electric machine.

[0035] The parking lock arrangement may include a separate actuator by means of which the pawl is actuated at least indirectly. Alternatively, the transmission 1 may be designed so 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 when the parking lock is activated, the parking lock can be activated even when the vehicle is still rolling or driven at very low speeds, without damaging the motor.

[0036] Reference Signs List

[0037] 1 Transmission

[0038] 2 Input shaft

[0039] 3 Synchronizer

[0040] 4 Rotor shaft

[0041] 5 friction disc

[0042] 6 First synchronizer ring

[0043] 7 Second synchronizer ring

[0044] 8 Clutch body

[0045] 9 Sliding sleeve

[0046] 10 Transmission housing

[0047] 11 Inner teeth of the first synchronizer ring

[0048] 12 External teeth of the rotor shaft

[0049] 13 Internal teeth of the clutch body

[0050] 14 First external tooth portion of input shaft

[0051] 15 First bearing element

[0052] 16 Second bearing element

[0053] 17 Second external tooth portion of input shaft

[0054] 18 Parking lock gear

[0055] 19 Parking lock gear teeth

[0056] 20 Friction surface of the second synchronizer ring

[0057] 21 cone

[0058] 22 Third bearing element

[0059] 23 Fourth bearing element

[0060] 24 Locking tooth of the first synchronizer ring

[0061] 25 Locking tooth of the second synchronizer ring

[0062] 26 Locking teeth of the clutch body.

Claims

1. A transmission device (1) for at least partially electrically driving a vehicle, the transmission device comprising: An input shaft (2) capable of being coupled to a rotor shaft (4) of an electric motor via a synchronizing device (3); at least one friction disc (5) axially located between a first synchronizing ring (6) and a second synchronizing ring (7), the first synchronizing ring being connected to the rotor shaft (4) for common rotation; a clutch body (8) connected to the input shaft (2) for common rotation; and a sliding sleeve (9) capable of sliding axially along the clutch body (8), wherein the sliding sleeve (9) is designed to be axially moved relative to the clutch body (8) by an actuating element to initiate synchronization of the second synchronizing ring (7) and to establish a connection with the two synchronizing rings (6, 7) for common rotation, thereby coupling the rotor shaft (4) to the input shaft (2), a parking lock gear (18) having a toothing (19) being arranged on the input shaft (2), wherein the parking lock gear (18) is designed so that a pawl for preventing rotation of the input shaft (2) engages with the toothing (19).

2. The transmission device (1) according to claim 1, It is characterized by: A cone (21) for receiving the second synchronizer ring (7) is formed on the first synchronizer ring (6).

3. The transmission device (1) according to claim 1, It is characterized in that The first synchronizer ring (6) has an inner tooth portion (11), and the inner tooth portion of the first synchronizer ring meshes with an outer tooth portion (12) formed on the rotor shaft (4).

4. The transmission device (1) according to claim 1, It is characterized in that The clutch body (8) has an internal tooth portion (13) that meshes with an external tooth portion (14) formed on the input shaft (2).

5. Transmission device (1) according to any one of the preceding claims, It is characterized in that The input shaft (2) is coaxially mounted to the rotor shaft (4) by means of at least a first bearing element and a second bearing element.

6. The transmission device (1) according to claim 5, It is characterized in that The first bearing element and the second bearing element are designed to support the input shaft (2) at least radially relative to a housing (10) of the transmission (1).

7. The transmission device (1) according to claim 5, It is characterized in that The rotor shaft (4) is designed to be at least partially hollow at the end facing the input shaft (2) to receive the first bearing element (15) for mounting the input shaft (2).

8. A vehicle comprising a transmission (1) according to any one of claims 1 to 7.

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