Clutch assembly with two hydraulically actuated clutch devices

Abstract

The invention relates to a hydraulic assembly (1) for an electrically operable multi-gear axle drive train (2) of a motor vehicle (3), comprising a first clutch device (4) and a second clutch device (5) for actuating at least one gear selection device (6) of the electrically operable axle drive train (2), and comprising a central release mechanism (7) comprising a first central release mechanism piston (10) which is movable in a translatory manner relative to a central release mechanism housing (9) which is fixed in rotation to a drive train housing (8), and a second central release mechanism piston (13) which is movable in a translatory manner relative to the central release mechanism housing (9) which is fixed in rotation to the drive train housing (8), wherein a radially outer lateral surface (15) of the central release mechanism housing (9) has a groove (16) into which a shell-like toothed element (17) with an outer toothing (18) is inserted and connected in an axially fastening and torque-transmitting manner, and the outer toothing (18) engages into a corresponding toothing which is fixed in rotation to the drive train housing (8).

Description

Technical Field

[0001] This invention relates to a hydraulic assembly for an electrically operable multi-gear drivetrain of a motor vehicle, the hydraulic assembly including a first clutch device and a second clutch device for actuating at least one gear selection device of the electrically operable drivetrain, and a central release mechanism having: a first central release mechanism piston movable in a translational manner relative to a central release mechanism housing fixed non-rotatably to a drivetrain housing, wherein a first pressure chamber is defined between the central release mechanism housing and the first central release mechanism piston, into which hydraulic fluid can be introduced and pressurized such that the first central release mechanism piston can be moved hydraulically relative to the central release mechanism housing; and a second central release mechanism piston movable in a translational manner relative to the central release mechanism housing fixed non-rotatably to the drivetrain housing, wherein a second pressure chamber is defined between the central release mechanism housing and the second central release mechanism piston, into which hydraulic fluid can be introduced and pressurized such that the second central release mechanism piston can be moved hydraulically relative to the central release mechanism housing. Background Technology

[0002] Electric motors are increasingly being used to power motor vehicles as an alternative to internal combustion engines that require fossil fuels. Significant efforts have been made to improve the suitability of electric drives for everyday use and to provide users with the driving comfort they are accustomed to.

[0003] A detailed description of the electric drive can be found in an article by Erik Schneider, Frank Fickl, Bernd Cebulski, and Jens Liebold published in ATZ magazine, May 2011, Vol. 113, pp. 360-365, entitled “Hochintegrativ und Flexibel Elektrische Antriebseinheit für E-Fahrzeuge” [Highly integrative and flexible electric drive unit for e-vehicles], which is perhaps the closest prior art. The article describes a drive unit for a vehicle axle comprising an electric motor arranged concentrically and coaxially with a bevel gear differential, wherein a shiftable 2-speed planetary gear set is arranged in the transmission system between the electric motor and the bevel gear differential, the planetary gear set also being coaxially positioned with the electric motor or the bevel gear differential or the spur gear differential. This drive unit is very compact and achieves a good trade-off between climbing ability, acceleration, and energy consumption thanks to its shiftable 2-speed planetary gear set. Such a drive unit is also known as an electric axle or an electrically operated transmission.

[0004] Such electrically operated transmissions with multi-gear shifting mechanisms typically require hydraulic components for the shifting process. Hydraulic components, such as a central release mechanism, are used in vehicles with multi-gear electric axles, and interact with the clutch and / or brake to change gears without interrupting traction. Summary of the Invention

[0005] The purpose of this invention is to provide a hydraulic assembly for an electrically operable multi-gear axle drive system of a motor vehicle, which can be produced inexpensively and allows for easy adaptation to different installation space conditions in the axle drive system.

[0006] This objective is achieved by a hydraulic assembly for an electrically operable multi-gear drivetrain of a motor vehicle, the hydraulic assembly including a first clutch device and a second clutch device for actuating at least one gear selection device of the electrically operable drivetrain, and a central release mechanism having: a first central release mechanism piston, the first central release mechanism piston being translatably movable relative to a central release mechanism housing fixed non-rotatably to the drivetrain housing, wherein a first pressure chamber is defined between the central release mechanism housing and the first central release mechanism piston, hydraulic fluid being introduced into the first pressure chamber and pressurized such that the first central release mechanism piston is hydraulically movable relative to the central release mechanism housing. The device includes a central release mechanism piston, which is translatably movable relative to a central release mechanism housing fixed non-rotatably to the drivetrain housing. A second pressure chamber is defined between the central release mechanism housing and the second central release mechanism piston. Hydraulic fluid can be introduced into the second pressure chamber and pressurized such that the second central release mechanism piston can be hydraulically moved relative to the central release mechanism housing. The central release mechanism housing has a groove on its radially outer lateral surface. A shell-shaped toothed element with external teeth is inserted into the groove and connected to the groove in an axially fastened and torque-transmitting manner. The external teeth engage with corresponding teeth formed non-rotatably relative to the drivetrain housing.

[0007] This offers the following advantages: the central release mechanism can be manufactured independently of the tooth geometry predetermined by the mounting space of the axle drivetrain, and adaptability to the mounting space can be achieved via a separate toothed element that can be manufactured inexpensively. Therefore, the tooth geometry integrally formed with the central release mechanism housing can be omitted. Furthermore, by means of the toothed element arranged in a groove, axial fixation and preferably radial fixation of the central release mechanism housing relative to the drivetrain housing can preferably be achieved.

[0008] Preferably, the groove can be designed to be completely closed in the circumferential direction, i.e., without interruption, or to have interruptions in the circumferential direction, thereby achieving a segmented groove in the circumferential direction. The groove preferably has a rectangular cross-section. Correspondingly, the toothed element preferably has a rectangular base body from which external teeth extend radially outward, wherein the base body engages in a precisely fitted manner within the rectangular groove. The groove can, for example, be introduced directly into the central release mechanism housing during the manufacturing process, e.g., as part of an injection molding or die-casting process, or the groove can, for example, be machined into the central release mechanism housing after a single molding process.

[0009] In particular, individual toothed elements can be fixed in the groove by form fit, force fit and / or material bonding.

[0010] First, the various elements of the claimed subject matter of the present invention are explained in order of these elements, and particularly preferred embodiments of the subject matter of the present invention are described below.

[0011] The electric drivetrain of a motor vehicle includes a motor and a transmission, wherein the motor and the transmission form a structural unit. Specifically, the motor and the transmission can be arranged within a common drivetrain housing. Alternatively, the motor can also have a motor housing, and the transmission can also have a transmission housing, wherein the structural unit can then be implemented by fixing the transmission relative to the motor. This structural unit is sometimes also referred to as an electric drive axle. The motor and the transmission can also be housed within the drivetrain housing. The drivetrain housing is configured to at least accommodate the motor and the transmission.

[0012] An electric motor is used to convert electrical energy into mechanical energy and / or mechanical energy into electrical energy, and typically includes a stationary portion called a stator, support, or armature, and a portion called a rotor or wheel arranged to move relative to the stationary portion. In the case where the motor is designed as a rotary machine, a distinction is made particularly between radial-flux and axial-flux machines. A radial-flux machine is characterized by magnetic field lines extending radially in the air gap formed between the rotor and stator, while in the case of an axial-flux machine, the magnetic field lines extend axially in the air gap formed between the rotor and stator. In conjunction with this invention, the motor can be designed as either a radial-flux or axial-flux machine. In particular, the motor is intended for use in electrically operated transmission systems of motor vehicles.

[0013] Specifically, the motor is sized to enable vehicle speeds exceeding 50 km / h, preferably exceeding 80 km / h, and particularly exceeding 100 km / h. The motor particularly preferably has an output exceeding 30 kW, preferably exceeding 50 kW, and particularly exceeding 70 kW. Furthermore, it is preferred that the motor provides speeds greater than 5000 rpm, particularly preferably greater than 10000 rpm, and very particularly preferably greater than 12500 rpm.

[0014] Specifically, the drive unit of the electric vehicle's shaft drive system can be connected to a motor designed to generate drive torque for the motor vehicle. This drive torque is particularly preferably a main drive torque, such that the motor vehicle is driven solely by this drive torque.

[0015] The transmission is particularly preferably designed to be multi-gear and shiftable.

[0016] A transmission system can include a differential transmission. A differential transmission is a planetary gear system with one input and two outputs. Differential transmissions typically function to drive the two wheels of a motor vehicle at different speeds while maintaining the same propulsive force, even in corners.

[0017] The central release mechanism includes a central release mechanism housing. The housing houses the various components of the central release mechanism, particularly the movable piston, and protects these components from external mechanical or chemical influences. Furthermore, the housing allows for easy assembly and fixation of the central release mechanism within the transmission system. Preferably, the housing is formed of plastic, metal, and / or ceramic materials. The housing can be manufactured as one or more pieces. According to the invention, the housing has a groove on its radially outer lateral surface, into which a shell-shaped toothed element with external teeth is inserted and connected axially and torque-transmittingly.

[0018] The central release mechanism also has a central release mechanism piston. The central release mechanism piston functions to convert hydraulic pressure into linear displacement, which, for example, allows a clutch system to transition from an engaged to an disengaged state. The central release mechanism can have an annular central release mechanism piston or multiple central release mechanism pistons (multi-piston release mechanism).

[0019] The hydraulic assembly also includes a first clutch device and a second clutch device. For example, the clutch device can be designed as a disc clutch, a multi-disc clutch, a gear clutch, etc. The clutch device can also be configured as a brake, for example by fixing the inner or outer disc of a multi-disc clutch in a non-rotatable manner relative to the axle drive housing.

[0020] The central release mechanism can be configured such that the first central release mechanism piston can be actuated independently of the second central release mechanism piston. However, it is preferred that the two central release mechanism pistons are actuated synchronously.

[0021] Preferably, the piston of the first central release mechanism interacts with the clutch device, such that movement of the piston causes engagement or disengagement of the first clutch device. Preferably, the piston of the second central release mechanism interacts with the second clutch device in a similar manner, such that movement of the piston causes engagement or disengagement of the second clutch device.

[0022] According to an advantageous embodiment of the invention, the first central release mechanism piston and the second central release mechanism piston are movable in the axial direction. According to a further preferred embodiment of the invention, the first central release mechanism piston and the second central release mechanism piston are movable in opposite directions. In this way, a particularly space-saving implementation of the axle drivetrain can be achieved.

[0023] Furthermore, according to an equally advantageous embodiment of the invention, the cross-section of the central release mechanism housing can have a double-T profile, which is particularly advantageous in terms of manufacturing technology.

[0024] According to another particularly preferred embodiment of the invention, the central release mechanism housing may have a cylindrical annular spatial shape, which may also contribute to the compact design of the axle drivetrain.

[0025] Furthermore, the invention can be further improved such that multiple cylindrical, annular, toothed elements are distributed on the circumference of the central release mechanism housing. In particular, the advantage of this design is that multiple toothed elements can be arranged on the circumference of the central release mechanism housing in a simple manner.

[0026] In another preferred embodiment of the invention, there may be at least two, preferably at least three, and very particularly preferably at least four toothed elements, wherein these toothed elements are formed to be substantially identical, thereby further optimizing manufacturing costs due to reduced component variations and larger batch sizes.

[0027] It is also advantageous to further improve the invention such that the toothed elements, one of the toothed elements, or all the toothed elements are formed of a material different from the central release mechanism housing. In another preferred embodiment of the subject matter of the invention, in this context, the toothed elements can be formed of a metallic material, particularly steel, and the central release mechanism housing can be formed of aluminum or plastic, particularly fiber-reinforced plastic.

[0028] Finally, the invention can also be advantageously implemented such that an axially fixed fastening ring is placed on at least one axial end face of the external teeth, the fastening ring being axially fixed relative to the transmission housing. Attached Figure Description

[0029] The invention will now be explained in more detail with reference to the accompanying drawings without limiting the overall concept of the invention.

[0030] In the attached diagram:

[0031] Figure 1 The hydraulic assembly is shown in a schematic axial cross-sectional view.

[0032] Figure 2The housing of the separate central release mechanism is shown in a three-dimensional axial cross-section.

[0033] Figure 3 The central release mechanism housing is shown in schematic cross-sectional view, and

[0034] Figure 4 A schematic block diagram illustrates a motor vehicle with an electrically operable axle drivetrain. Detailed Implementation

[0035] Figure 1 The hydraulic assembly 1 of an electrically operable multi-gear drivetrain 2 for a motor vehicle 3 is shown, wherein the motor vehicle is still Figure 4 The axle drivetrain 2 is shown in an exemplary manner. It has a motor 20 and a multi-gear shiftable transmission 21, which are enclosed by a common drivetrain housing 8.

[0036] The hydraulic assembly 1 has a first clutch device 4 and a second clutch device 5 for actuating at least one gear selection device 6 of an electrically operable axle drive system 2.

[0037] Furthermore, the hydraulic assembly 1 includes a central release mechanism 7 having a first central release mechanism piston 10 movable in a translational manner relative to a central release mechanism housing 9, which is non-rotatably fixed to the transmission housing 8. A first pressure chamber 11 is defined between the central release mechanism housing 9 and the first central release mechanism piston 10, into which hydraulic fluid 12 can be introduced and pressurized to allow the first central release mechanism piston 10 to move hydraulically relative to the central release mechanism housing 9.

[0038] A second central release mechanism piston 13 is provided in the central release mechanism housing 9, which is fixed to the transmission housing 8 in a non-rotatable manner. A second pressure chamber 14 is defined between the central release mechanism housing 9 and the second central release mechanism piston 13. Hydraulic fluid 12 can also be introduced into the second pressure chamber and pressurized so that the second central release mechanism piston 13 can move relative to the central release mechanism housing 9 in a hydraulic manner.

[0039] from Figure 1 It can also be seen that the first central release mechanism piston 10 and the second central release mechanism piston 13 can move axially in opposite directions.

[0040] The central release mechanism pistons 10 and 13 are operatively connected to the clutch devices 4 and 5, respectively, such that axial movement of the central release mechanism pistons 10 and 13 causes engagement or disengagement of the corresponding clutch devices 4 and 5. In the illustrated exemplary embodiment, the clutch devices 4 and 5 are designed as brakes, which interact with the gear selection device 6 of the shiftable transmission 21 such that gear changes in the shiftable transmission 21 are achieved by engaging or braking or disengaging the brakes.

[0041] The central release mechanism housing 9 has a groove 16 on its radially outer lateral surface 15. A plurality of shell-shaped toothed elements 17 with external teeth 18 are inserted into this groove and connected to it in an axially fastened and torque-transmitting manner. The external teeth 18 engage with corresponding teeth formed in a non-rotatable manner relative to the transmission housing 8. The external teeth 18 and the corresponding teeth of the transmission housing 8 form a spline, allowing the central release mechanism housing 9 to be inserted into the transmission housing 8 axially. For axial fastening, axially fixed fastening rings 19 are placed on each of the two axial end faces of the external teeth 18, and these fastening rings are axially fixed relative to the transmission housing 8.

[0042] like Figure 2 As shown, the cross-section of the central release mechanism housing 9 has a double T-shaped profile, wherein the central release mechanism housing 9 has a cylindrical annular spatial shape.

[0043] from Figure 3 As can be seen, multiple cylindrical, annular, toothed elements 17 are distributed on the circumference of the central release mechanism housing 9. In the illustrated embodiment, there are four toothed elements 17, which are formed to be substantially identical. All toothed elements 17 are formed of a different material than the central release mechanism housing 9.

[0044] exist Figures 1 to 3 In an exemplary embodiment, the toothed element 17 is formed of steel, and the central release mechanism housing 9 is formed of aluminum or plastic.

[0045] This invention is not limited to the embodiments shown in the accompanying drawings. Therefore, the above description should not be considered limiting but rather illustrative. The appended content should be understood to refer to the presence of a specified feature in at least one embodiment of the invention. This does not exclude the presence of other features. If the above description defines a “first” feature and a “second” feature, such designation is used to distinguish between two features of the same type, without specifying a priority order.

[0046] List of reference numerals

[0047] 1 Hydraulic components

[0048] 2. Axle Drive System

[0049] 3 Motor vehicles

[0050] 4. Clutch assembly

[0051] 5. Clutch assembly

[0052] 6-speed selection device

[0053] 7. Central Release Agency

[0054] 8. Transmission system housing

[0055] 9. Central release mechanism housing

[0056] 10. Central release mechanism piston

[0057] 11 Pressure Chamber

[0058] 12 Hydraulic fluid

[0059] 13. Central release mechanism piston

[0060] 14 Pressure Chamber

[0061] 15 Lateral surfaces

[0062] 16 Grooves

[0063] 17 Toothed elements

[0064] 18 External teeth

[0065] 19 Fastening ring

[0066] 20 motors

[0067] 21 Transmission device

Claims

1. A hydraulic assembly (1) for an electrically operable multi-gear drive system (2) of a motor vehicle (3), the hydraulic assembly comprising: First clutch device (4) and Second clutch device (5) The first clutch device and the second clutch device are used to actuate at least one gear selection device (6) of the electrically operable axle drive system (2), and Central release mechanism (7), said central release mechanism having: A first central release mechanism piston (10) is translatably movable relative to a central release mechanism housing (9), which is non-rotatably fixed to a transmission housing (8). A first pressure chamber (11) is defined between the central release mechanism housing (9) and the first central release mechanism piston (10). Hydraulic fluid (12) can be introduced into the first pressure chamber and pressurized such that the first central release mechanism piston (10) is hydraulically movable relative to the central release mechanism housing (9). A second central release mechanism piston (13) is translatably movable relative to a central release mechanism housing (9) which is non-rotatably fixed to the transmission housing (8), wherein a second pressure chamber (14) is defined between the central release mechanism housing (9) and the second central release mechanism piston (13), and hydraulic fluid (12) is introduced into the second pressure chamber and pressurized such that the second central release mechanism piston (13) is hydraulically movable relative to the central release mechanism housing (9). Its features are, The central release mechanism housing (9) has a groove (16) on the radially outer lateral surface (15) of the central release mechanism housing. A shell-shaped toothed element (17) with external teeth (18) is inserted into the groove and connected to the groove in an axially fastened and torque-transmitting manner, wherein the external teeth (18) engage in corresponding teeth formed in a non-rotatable manner relative to the transmission housing (8).

2. The hydraulic assembly (1) according to claim 1. Its features are, The first central release mechanism piston (10) and the second central release mechanism piston (13) are capable of moving in the axial direction.

3. The hydraulic assembly (1) according to claim 1 above. Its features are, The first central release mechanism piston (10) and the second central release mechanism piston (13) are capable of moving in opposite directions.

4. The hydraulic assembly (1) according to claim 1 above. Its features are, The cross-section of the housing (9) of the central release mechanism has a double T-shaped profile.

5. The hydraulic assembly (1) according to claim 1 above. Its features are, The housing (9) of the central release mechanism has a cylindrical annular spatial shape.

6. The hydraulic assembly (1) according to any one of claims 1 to 5. Its features are, Multiple cylindrical annular toothed elements (17) are distributed on the circumference of the central release mechanism housing (9).

7. The hydraulic assembly (1) according to claim 6. Its features are, There are at least two of the toothed elements (17), wherein the toothed elements (17) are formed to be substantially identical.

8. The hydraulic assembly (1) according to any one of claims 1 to 5. Its features are, The toothed element (17), one of the toothed elements (17), or all the toothed elements (17) are formed of a material different from that of the central release mechanism housing (9).

9. The hydraulic assembly (1) according to any one of claims 1 to 5. Its features are, The toothed element (17) is made of metal, and the housing (9) of the central release mechanism is made of aluminum or plastic.

10. The hydraulic assembly (1) according to claim 9. Its features are, The toothed element (17) is made of steel.

11. The hydraulic assembly (1) according to claim 9, wherein the central release mechanism housing (9) is formed of fiber-reinforced plastic.

12. The hydraulic assembly (1) according to claim 1 above. Its features are, An axially fixed fastening ring (19) is placed on at least one axial end face of the external toothed portion (18), the fastening ring being axially fixed relative to the transmission housing (8).

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