drive system

Abstract

The present invention relates to a drive system (1) having a drive unit (2) having at least one motor and a transmission device (3), the transmission device having two sub-transmission devices, each sub-transmission device having at least one gear and each having a clutch (7, 8), the clutches being arranged between the rotor of the at least one motor and the corresponding transmission input shafts (4, 5) of the sub-transmission devices. To ensure safe and fail-safe operation of the drive system (1), especially in emergency operation, a first clutch (7) of the two clutches is configured to be closed in the non-operational state, and a second clutch (8) is configured to be open in the non-operational state.

Description

Technical Field

[0001] The present invention relates to a drive system having at least one motor and a transmission device having two sub-transmission devices, each sub-transmission device having at least one gear and each having a clutch, the clutch being arranged between the rotor of the at least one motor and the corresponding transmission input shaft of the sub-transmission device. Background Technology

[0002] According to document DE 10 2018 120 176 A1, a drive system having a motor and a transmission device is known. The transmission device has two transmission device input shafts and a common transmission device output shaft. A double clutch is provided between the motor and the transmission device, and a clutch is provided between the motor and the transmission device input shaft respectively. Summary of the Invention

[0003] The objective of this invention is to further improve such drive systems. In particular, the objective of this invention is to provide a drive system with electrically operated axles that can operate safely and fail-safely with a flawed control system in emergency situations.

[0004] This task is solved by the drive system according to the invention. Advantageous embodiments according to the invention are given in the specification.

[0005] The proposed drive system is used to operate a motor vehicle by means of a drive unit that operates either purely electrically, consisting of at least one electric motor, or hybridally, consisting of an internal combustion engine and an electric motor. It should be understood that the drive unit may include additional electric motors, and / or at least one electric motor may be provided on the transmission side (e.g., on at least one transmission input shaft and / or on one and / or two transmission output shafts).

[0006] To adapt the rotational speed of the drive unit to the wheel speed of the vehicle's drive wheels, a transmission device is provided. This transmission device consists of two sub-transmission devices, each having at least one gear and a clutch arranged between the rotor of at least one motor and the corresponding input shaft of each sub-transmission device. These sub-transmission devices can each be formed by a transmission input shaft and a transmission output shaft, with meshing spur gears arranged between them, for example, to form a corresponding or unique gear. Here, these transmission output shafts are connected to each other at the output end of the transmission, for example, at the differential. Alternatively, a single transmission output shaft can be provided, with a spur gear pair arranged between this output shaft and the two transmission input shafts, forming one or more gears.

[0007] To ensure safe (i.e., without distortion and similar issues should the components used to operate the clutch fail) and fail-safe (i.e., with sufficient power and in a manner exceeding pure ruddering), the first clutch is configured to be closed in the non-operational state, and a second clutch is configured to be open in the non-operational state. This means that in the event of a failure in the clutch operating system, the first clutch remains closed or engaged, and the second clutch remains open or disengaged. Therefore, the vehicle can continue to operate using the proposed drive system via a sub-transmission with the first clutch. The starting clutch function of the first clutch is not necessary in the event of a disturbance to the operating system, as starting can be initiated from zero speed using at least one motor.

[0008] Each sub-transmission unit can have a single gear or multiple gears. Here, the transmission unit switches in such a way that, at least in the sub-transmission unit with a first clutch, in the event of a malfunction or disturbance in the operation of the friction clutch, the gear with the smaller gear ratio remains engaged or engaged, thereby maintaining or reducing the speed of the drive unit in the event of a clutch malfunction. "Smaller gear ratio" here should be understood as a slower gear ratio, or a "larger gear ratio". (e.g., longer) The gear ratios, gears that move towards overdrive, or similar expressions are used. For example, in the event of a malfunction when the clutch and shift clutch are switched simultaneously when necessary, the multiple gears of a sub-drive with a first gear ratio can be configured by means of the shift clutch to engage or remain engaged by means of the shift clutch, for example by the corresponding axial preload of the shift clutch, while one or more other gear ratios are designed. In a drivetrain having a corresponding gear ratio for each sub-drive, the sub-drive with the first clutch preferably has a smaller gear ratio than the sub-drive with the second clutch.

[0009] According to an advantageous embodiment, in addition to an alternative embodiment having a dry-running friction clutch (which has a clutch disc pressure plate, an axially movable clamping plate, and friction linings axially clamped therein), the clutch can also operate wetly. The clutch can be configured as a dual-clutch, which receives two clutches within a housing. The dual-clutch preferably has a single input component, such as an input shaft, which is divided into two output components by means of the two clutches. These output components are, for example, rotatably locked to the input shaft of a sub-transmission of a drivetrain.

[0010] A wet-operated clutch can be constructed as a plate clutch, which has a plate group consisting of alternating stacked input and output plates, and the disengagement element of the actuating element loads these plates axially.

[0011] The first-plate clutch plate assembly is preloaded here by means of an axially acting spring element, particularly a disc spring, against an axially fixed end plate. Here, the operating element pushes or pulls axially at the spring element and releases the preload of the spring element relative to the plate assembly, thereby disengaging the first-plate clutch.

[0012] In the second-plate clutch, the corresponding operating element of the operating system pre-tightens the plate assembly of the operating system against the axially fixed end stop, so that the second-plate clutch closes as the pre-tightening increases.

[0013] The operating element for manipulating the first plate clutch is arranged on the opposite side of the spring element relative to the plate assembly of the first plate clutch. The operating element has axially widened, peripherally distributed fingers that axially pass through the plate assembly and release the preload of the spring element for operating the plate clutch. For example, the first plate of the plate assembly, preloaded by the spring element, can move axially against the action of the spring element.

[0014] The clutch is operated by an actuation system, which is electromechanically driven, for example by means of an electric motor, which axially moves the mechanical actuating element and is controlled by a controller with an actuator transmission connected in between. For example, a so-called lever actuator can be provided. Alternatively, the clutch can be operated by an actuation system (e.g., hydraulically or hydrostatically), in which a pressure supply device (e.g., an electric motor-driven drive cylinder or a pump driven by an internal combustion engine or electric motor) applies pressure to a pressure medium, which is then applied via a pressure line to a driven cylinder, whose pressure piston or pressure tank axially actuates the corresponding clutch along the operating stroke.

[0015] To construct a hydraulically actuated operating system, for example, for each plate clutch, a pressure tank pressurized by a pressure supply device can be arranged around the plates of a first plate clutch, which is arranged to be torsionally about a rotation axis. Here, a corresponding rotation guide is provided between the pressure supply device and the pressure tank. For example, a pressure line can be guided from the pressure supply device via a corresponding switching valve through a pressure guide, which has a pressure inlet for entering the drilled shaft section and a pressure inlet for entering the piston / cylinder unit of the plate clutch from that shaft section. Each piston / cylinder unit contains a pressure tank that loads the plates, which acts as the piston of the piston / cylinder unit to actuate the corresponding plate clutch according to the applied operating pressure. A pressure compensation chamber can be provided to compensate for the volume of the pressure medium retained in the pressure chamber of the piston / cylinder unit.

[0016] To construct a hydrostatic control system, a driven cylinder, which can be loaded by a pressure supply device (e.g., a hydrostatic actuator), can be arranged to be fixed relative to the housing. An axial load is applied to a clutch (e.g., a plate clutch) rotating about a rotational axis, with an intermediate control bearing for rotational compensation; this control bearing is a release bearing in a first friction clutch and an engagement bearing in a second clutch.

[0017] According to an advantageous embodiment of the proposed drive system, the clutches are configured to be operable in the same axial direction. Thus, for example, it is possible to advantageously and uniformly configure the operating force, mounting space, mode of operation, and / or similar designs for each clutch.

[0018] To save axial installation space, the clutches can be arranged radially stacked. This allows the clutches to have substantially the same friction surface size. For example, in embodiments with plate clutches, the number of plates, the friction cross-section, and / or similar parameters can be designed accordingly. For instance, to advantageously construct the installation space, particularly when designing a dual-clutch system with plate clutches, and to avoid extensive overlap of the operating elements of the operating system, the first clutch can be arranged radially outward.

[0019] In a preferred embodiment of the proposed drivetrain, the spring element can be configured to gradually decrease along its characteristic curve after overcoming the maximum preload of the spring element, making it relatively less strenuous or energy-intensive to keep the clutch in the open state, thus allowing for a longer, more economically advantageous driving time when the first clutch is engaged. Based on the decreasing characteristic curve, the disengagement force at first clutch disengagement is less than the maximum preload of the spring element when the first clutch is engaged. Particularly advantageous economically is that the drivetrain operates when the first clutch is engaged and therefore in a long gear, since the operating system consumes no energy when the first clutch is engaged and the second clutch is disengaged.

[0020] The clutch is controlled by an operating system based on a characteristic curve of the operating stroke stored in the controller, which represents the torque that can be transmitted via the corresponding clutch. Here, the clutch characteristic curve is continuously adapted to long-term variations (e.g., wear) and short-term variations (e.g., temperature changes) by, for example, continuously taking sampling points and slopes of the characteristic curve. Alternatively, the operating stroke can be detected by means of a stroke sensor or by means of parameters related to the kinematics of the operating stroke (e.g., the rotational characteristic value of the motor given the gear ratio used for the operating element). To save on the stroke sensor and thus the installation space required for it, the pressure in the associated pressure lines can be detected, for example, by means of a pressure sensor and associated with the operating stroke. Attached Figure Description

[0021] According to Figure 1 and 2 The embodiments shown in the figures illustrate the invention in detail.

[0022] Figure 1 The upper part of the drive system, partially shown in cross-section and arranged around the axis of rotation, is also shown; and

[0023] Figure 2 Figure 1 The characteristic curve of the first clutch of the drive system. Detailed Implementation

[0024] Figure 1The upper part of the drive system 1, arranged around the axis of rotation d, is shown in cross-section. It includes: a drive unit 2, schematically shown only, of a pure electric or hybrid configuration, having an electric motor and, if necessary, an internal combustion engine; and a transmission 3, also schematically shown only, having two sub-transmissions, wherein only the transmission input shafts 4 and 5 are shown, and a dual clutch 6 arranged between the drive unit 2 and the transmission 3 is shown in cross-section. The dual clutch 6 comprises two radially stacked clutches 7 and 8, configured as wet-operation plate clutches 9 and 10. The first plate clutch 9 is configured as a forced-open (i.e., closed in a pressureless state and opened by means of operating pressure provided by the operating system 11) first clutch 7. The second plate clutch 10 is configured as a forced-close (i.e., open in a pressureless state and closed by means of operating pressure provided by the operating system 11) second clutch 8.

[0025] The clutches 7 and 8 are operated by means of an operating system 11, partially shown, which generates the operating pressure of the pressure medium by means of a pressure supply device (preferably in the form of an electrically operated pump), not shown. The pressure medium is fed to the piston / cylinder units 19 and 20 via the pipe block 12 and rotary inlets 13 and 14, through attached pressure lines 15 and 16 and connected pressure chambers 17 and 18, such that the desired operating pressure is applied to these piston / cylinder units according to the control of the pressure supply device or, in other words, through an intermediately connected bypass valve for operating the clutches 7 and 8. A rotary inlet 46 is arranged between the rotary inlets 13 and 14 for conveying the pressure medium at normal pressure, for example for cooling, supplying compensation chambers 23 and 24, and for separating the two rotary inlets 13 and 14 if necessary to guide higher operating pressures. The pressure tanks 21 and 22 of the piston / cylinder units 19 and 20, which serve as operating pistons, are axially moved by the applied operating pressure fed into the pressure chambers 17 and 18 via the rotary inlets 13 and 14. To compensate for the centrifugal force effect of the pressure medium volume of pressure chambers 17 and 18 rotating around the rotation axis d, the compensating chambers 23 and 24, which are equipped with normal pressure, are switched in the opposite direction to pressure chambers 17 and 18, so that only operating pressure is applied to pressure tanks 21 and 22.

[0026] In the first-plate clutch 9, which is configured for forced opening, the plate assembly 27, formed by plates 25 and 26 on the input and output sides, is preloaded against the support member 29 by means of an axially acting spring element 28, such as a disc spring. The operation (i.e., the opening process) of the first-plate clutch 9 is performed by the pressure tank 21, which, by means of its axially widened finger 30 passing through the plate assembly 27, causes the end plate 31 to move along the axial operating stroke against the action of the spring element 28 by means of the operating pressure provided by the pressure supply device. The finger 30 is fixed only in the end plate 31. This has the advantage that no additional frictional force is generated when the end plate 31 is operated, thereby producing relative movement of the finger 30 relative to the other plates 25 and 26, which, due to their hysteresis, could negatively affect the regulating behavior of the first clutch 7. Furthermore, it ensures that the finger 30 does not bend under centrifugal force at high speeds.

[0027] The clamping force of the spring element 28 is not linear and has a maximum value, which provides the maximum clamping force relative to the plate assembly 27. Therefore, in order to disengage the first plate clutch 9, an operating pressure at least corresponding to overcoming this maximum value is applied only briefly, after which the first plate clutch 9 is economically advantageously held open with an operating force much smaller than the operating pressure.

[0028] The second clutch 8 is constructed as a forced-closure second plate clutch 10, which is closed by the operating pressure applied to the pressure chamber 18 due to the movement of the pressure tank 22. Here, the pressure tank 22 pre-tightens the alternately stacked input and output plates 32, 33 of the plate group 35 against the axially fixed end plates 34 according to the operating pressure.

[0029] The plate supports 36 and 37, which receive the input side plates 25 and 32 in a torsion-resistant manner, are connected to the support component 29 in a torsion-resistant manner. The support component 29 is connected to the common input component 38 of the dual clutch 6, for example, by welding. The input component 38, which is constructed as a shaft component and includes rotating guides 13 and 14, is connected to the drive unit 2.

[0030] The output side brackets 39 and 40 of the anti-torsional receiving plates 26 and 33 are respectively anti-torsionally connected to the transmission input shafts 4 and 5 of a sub-transmission having at least one transmission ratio. Subsequently, at least one additional motor can be provided in at least one or more sub-transmissions. The transmission output shaft of the sub-transmission is connected to the drive wheels of the vehicle via a differential.

[0031] Due to installation space constraints, clutches 7 and 8 are operated axially in the same direction. The dual clutch 6 is force-balanced and is received axially and torsionally fixed relative to the housing by means of a provided support 45.

[0032] In the event of a malfunction or error in the control system 11, the system is switched without pressure, causing the first clutch 7 to engage or remain engaged and the second clutch 8 to disengage or remain disengaged. Preferably, the sub-transmission associated with the first clutch 7 has a fixed gear ratio that is smaller (e.g., longer) than the currently switched gear ratio relative to a fixed setting of the other sub-transmission, or is switched to such a gear ratio in the case of multiple gears, so that the speed of the clutches 7 and 8, or in other words, the speed of the transmission 3 with the sub-transmission, does not increase in the event of a malfunction in the control system 11. Emergency operation of the motor vehicle can be achieved using the sub-transmission associated with the first clutch 7, and if necessary, by starting from this state, because the drive unit 2 includes a motor. Due to the characteristics of this drive unit, the motor vehicle can be started from this state by means of this drive unit without speed compensation.

[0033] Figure 2 refer to Figure 1 The drive system 1 is shown in graph 41, which shows the clamping force F of the spring element 28, or the operating pressure p for disengaging the first clutch 7, along the operating stroke s. Characteristic curve 42 shows the maximum clamping force F. max The operating range of the first clutch 7 is set at the stroke points s=0 and s=0. max In order to operate the first clutch 7, use the force corresponding to the maximum clamping force F. max Maximum operating pressure p max As the operating stroke increases, the clamping force F of the spring element 28 decreases, and the required operating pressure p, shown in curve 43, decreases in the direction of arrow 44 along the operating stroke, so that the first clutch 7 can remain open under a small operating pressure p.

[0034] List of reference numerals

[0035] 1 Drive System

[0036] 2 drive units

[0037] 3. Transmission device

[0038] 4. Input shaft of transmission device

[0039] 5. Input shaft of transmission device

[0040] 6 Dual-clutch

[0041] 7 First Clutch

[0042] 8 Second Clutch

[0043] 9 First-plate clutch

[0044] 10 Second-plate clutch

[0045] 11. Operating System

[0046] 12 bearing blocks

[0047] 13 Rotating threading section

[0048] 14 Rotating threading section

[0049] 15 Pressure piping

[0050] 16 Pressure piping

[0051] 17. Pressure Chamber

[0052] 18 Pressure Chamber

[0053] 19 Piston / Cylinder Unit

[0054] 20 Piston / Cylinder Unit

[0055] 21 Pressure Tank

[0056] 22 Pressure Tanks

[0057] 23 Compensation cavity

[0058] 24 Compensation cavity

[0059] 25 pieces

[0060] 26 pieces

[0061] 27-piece set

[0062] 28 Spring elements

[0063] 29. Bracket Components

[0064] 30 finger-shaped components

[0065] 31 End piece

[0066] 32 pieces

[0067] 33 pieces

[0068] 34 end pieces

[0069] 35-piece set

[0070] 36-piece support

[0071] 37-piece support

[0072] 38 Input Components

[0073] 39-piece support

[0074] 40 support pieces

[0075] 41-line chart

[0076] 42 Characteristic Curves

[0077] 43 curves

[0078] 44 arrows

[0079] 45 Support section

[0080] 46. ​​Piercing section

[0081] d. Rotation axis

[0082] F clamping force

[0083] F max Maximum clamping force

[0084] p Manipulating pressure

[0085] p max Maximum operating pressure

[0086] s control stroke

[0087] s max Maximum operating travel

Claims

1. A drive system (1) having a drive unit (2) having at least one motor and a transmission device (3), the transmission device having two sub-transmission devices, each sub-transmission device having at least one gear and each having a clutch, the clutches being arranged between the rotor of the at least one motor and the corresponding transmission input shaft of the sub-transmission device, characterized in that, The first clutch (7) is configured to be closed in the non-operational state, and the other second clutch (8) is configured to be open in the non-operational state. The clutch is configured as a plate clutch, and the plate group (27) consisting of the alternating stacked input and output plates of the first plate clutch (9) is axially preloaded against the support member (29) by means of an axially acting spring element (28). The operating element of the first plate clutch (9) is arranged on the opposite side of the spring element (28) and passes axially through the plate group (27) by means of an axially widened finger (30) to release the preload of the spring element (28) for operating the plate clutch (9).

2. The drive system (1) according to claim 1, characterized in that, Each of the sub-transmission devices has a unique gear, wherein the sub-transmission device with the first clutch (7) has a smaller gear ratio than the sub-transmission device with the second clutch (8).

3. The drive system (1) according to claim 1, characterized in that, A pressure tank capable of being pressurized by a pressure supply device, together with the plate clutch, is arranged around a rotation axis d, and a rotating guide is provided between the pressure supply device and the pressure tank (21).

4. The drive system according to claim 1, characterized in that, The driven cylinder, which can be loaded by a pressure supply device, is arranged to be fixed relative to the housing and with a release bearing connected in the middle, thus releasing the preload of the spring element for operating the first plate clutch.

5. The drive system (1) according to any one of claims 1 to 4, characterized in that, The clutch is configured to be operated in the same axial direction.

6. The drive system (1) according to any one of claims 1 to 4, characterized in that, The clutches are arranged in a radially overlapping manner.

7. The drive system (1) according to claim 4, characterized in that, The first clutch (7) is arranged radially outward.

8. The drive system (1) according to any one of claims 1 to 4, characterized in that, The disengagement force when the first clutch (7) disengages is less than the maximum clamping force F of the spring element (28) when the first clutch (7) engages. max .

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