Hydraulic system and drive unit

Abstract

The present invention relates to a hydraulic system that supplies fluid to at least one electric motor for cooling and actuation of a clutch device. Additionally, the present invention also relates to a drive unit for electrically driving a powertrain of a motor vehicle. The hydraulic system (1) includes a volume flow source (10), in particular a pump, and electric motors (110, 120) to be cooled and a clutch actuator (3) for actuating a clutch device (2), and a switching device (21) by which the fluid volume flow from the volume flow source (10) is sequentially supplied to the electric motors (110, 120) and the clutch actuator (3).

Description

Field of the Invention

[0001] The present invention relates to a hydraulic system for supplying fluid to at least one electric motor, in particular an electric motor of a hybrid module, in order to cool at least one rotating component in the electric motor and to actuate a clutch device. The present invention also relates to a drive unit for electrically driving a motor vehicle, in particular a driveline of a hybrid motor vehicle, and having a hydraulic system according to the present invention.

[0002] The present invention particularly relates to a hydraulic actuator which can be used in a series hybrid transmission. Background Art

[0003] In the prior art, drive devices for hybrid motor vehicles are known, which mainly comprise an internal combustion engine, a first electric motor and a second electric motor.

[0004] For this purpose, DE 10 2015 222 690 A1, DE 10 2015 222 691 A1 and WO 2017 084 887 A1 illustrate control methods for such drive devices, during which the drive devices can be operated in a plurality of operating modes.

[0005] DE 10 2015 222 690 A1 mainly illustrates a series hybrid mode, in which transmission torque is generated by the second electric motor, and the internal combustion engine drives the first electric motor to generate electrical energy. An explanation is made of how the internal combustion engine operates at the operating point, and for this purpose the overall efficiency of the drive device depends on the efficiency of the internal combustion engine and the efficiency of the first electric motor.

[0006] DE 10 2015 222 691 A1 and WO 2017 084 887 A1 illustrate a performance-oriented and a consumption-oriented mode, each of which depends on conditions. The conditions include increasing a target drive value to an intermediate value which lies between an internal combustion engine threshold and a parallel hybrid mode threshold, where the internal combustion engine threshold represents the maximum drive value in the parallel hybrid mode, in which only the internal combustion engine generates transmission torque, and the parallel hybrid mode threshold represents the maximum drive value of the internal combustion engine in the parallel supercharged hybrid mode.

[0007] DE 10 2015 222 692 A1, WO 2017 084 888 A1, DE 10 2015 222 694 A1 and WO2017 084 889 A1 illustrate a method for operating a drive device of a hybrid motor vehicle and thus driving drive wheels, for which the drive device comprises an internal combustion engine, a first electric motor coupled to the internal combustion engine, a second electric motor, a storage battery and a main clutch located between the internal combustion engine and the drive wheels.

[0008] It is described in DE 10 2015 222 692 A1 and WO 2017 084 888 A1 that the drive device operates in one of three operating modes, namely pure electric mode, series hybrid mode or parallel hybrid mode, wherein the transmission torque provided when switching from the first operating mode to the second operating mode conforms to an appropriately selectable change curve between the transmission torque provided before and after the switch.

[0009] It is disclosed in DE 10 2015 222 694 A1 and WO 2017 084 889 A1 that a gearbox is also arranged between the internal combustion engine and the drive wheels.

[0010] Furthermore, the respective documents mentioned also describe a hybrid motor vehicle having a hybrid drive device.

[0011] DE 102016213318 A1 discloses a method in the form of hysteresis control for maintaining the pressure level of hydraulic fluid in a hydraulic actuating device, in particular for maintaining the pressure level above a target pressure value assigned to the operating point. In this regard, in the hydraulic actuating device, a hydraulic cylinder is connected to a volume flow source through a pressure line filled with hydraulic fluid, and the operating point conforms to the position of the actuating device.

[0012] WO2012 / 113368A1 discloses a hydraulic device, in particular a hydraulic device for actuating a clutch, which has a hydraulic working cylinder arranged near the clutch. In this regard, the working cylinder is connected to a volume flow source through a hydraulic line. The volume flow of the volume flow source can be influenced by a control unit according to the signals emitted by sensors assigned to the hydraulic device. The volume flow source is formed by a combination or unit that includes an electric motor and a pump and is arranged in a common housing.

[0013] It is also known that electric motors can be cooled by means of a hydraulic system. These electric motors are mainly designed as wet motors so that these electric motors can operate within an optimal temperature range and thus within an optimal efficiency range.

[0014] The hybrid motor vehicle repeatedly described in the prior art includes an internal combustion engine, a first and a second electric motor, at least one drive wheel, a main clutch, and a first and a second clutch. In this regard, the main clutch is arranged between the internal combustion engine and the drive wheels, the first clutch is provided between the output shaft of the first electric motor and the internal combustion engine, and the second clutch is provided between the second electric motor and the drive wheels. Summary of the Invention

[0015] Based on this, the object of the present invention is to provide a hydraulic system and a drive unit equipped with this hydraulic system, by means of which an electric drive can be cooled and operated at low cost, saving energy and space, especially in operation in combination with an internal combustion engine.

[0016] The task is solved by the hydraulic system according to claim 1 of the present invention and by the drive unit according to claim 11 of the present invention. Advantageous embodiments of the hydraulic system are described in the dependent claims 2 - 10.

[0017] The features of the claims can be combined in any technically reasonable way and method, for which reference can also be made to the descriptions in the following specification and the features in the drawings, which contain supplementary embodiments of the present invention.

[0018] The present invention relates to a hydraulic system for supplying fluid to at least one electric motor, especially the electric motor of a hybrid module, in order to cool at least one rotating component in the electric motor and to actuate a clutch device, especially the clutch device of a hybrid module. The hydraulic system includes a volumetric flow source, especially a pump, and the electric motor to be cooled and a clutch actuator for actuating the clutch device. The hydraulic system also has a switching device, by means of which the volumetric fluid flow from the volumetric flow source is successively conveyed to the electric motor or the clutch actuator.

[0019] The case of correspondingly arranging the switching device should not be excluded here, so that cooling of the electric motor and the clutch actuator can also be provided simultaneously.

[0020] Therefore, the main function of the present invention is to cool the electric motor, and the secondary function is clutch actuation.

[0021] From this, the pump is designed according to the volumetric flow required for the cooling function. Then the pressure level for clutch actuation is derived from this volumetric flow. From this, a low-pressure system is obtained, which is designed for a pressure in the range of approximately 10 bar.

[0022] In addition, the hydraulic system is also advantageously designed,

[0023] which includes a control device, which is specifically arranged so that it can correspondingly control the switching device to successively supply the electric motor or the clutch actuator. At this time, the control device can also be designed as a regulating device.

[0024] The control device should be advantageously arranged such that when the fluid pressure at the clutch actuator drops below the specified lower threshold, the switching device switches from cooling the electric motor to supplying the clutch actuator; and when the fluid pressure at the clutch actuator rises above the specified upper threshold, the switching device switches from supplying the clutch actuator to cooling the electric motor.

[0025] Accordingly, it is stipulated that the control device performs hysteresis control. For this purpose, the clutch actuator can over-press the actuated clutch device to reduce the average hydraulic level.

[0026] This means that the clutch device is pressed with a maximum force higher than that required to transmit the maximum torque, and then the hydraulic device section is connected through the valve position. Although the clutch actuator can now ensure cooling again, due to leakage losses, the pressure in the clutch section and thus the torque that can be transmitted on the clutch device will decrease. Once the transmissible torque drops below the lower threshold, the clutch branch is reconnected to the volume flow source and the pressure is increased again. Through this control, it is ensured that no undesirable slip occurs on the clutch device, but at the same time the pressure level in the system remains at a low level for most of the time for cooling. Therefore, in a hybrid motor vehicle equipped with a hydraulic system according to the present invention, valuable energy can be saved by virtue of the linear influence of the pressure on the energy consumption of the pump or the volume flow source.

[0027] In this regard, reference should also be made to the content published in DE 102016213318 A1, the subject of which is a method for maintaining the hydraulic pressure level in a hydraulic actuating device, in particular maintaining the pressure level higher than the target pressure value assigned to the operating point.

[0028] If pressure regulation is involved, the disclosure of this document is hereby expressly incorporated in this application.

[0029] In an embodiment of the switching device, it is stipulated that the device is a first reversing valve, in particular a two-way three-way valve. This valve can be designed as a so-called seat valve or slide valve.

[0030] Furthermore, in an advantageous embodiment, the hydraulic system can have a pressure reducing device for selectively reducing the pressure on the clutch actuator. For this purpose, the pressure reducing device is mainly a second reversing valve. The second reversing valve can in particular be a two-way two-way valve.

[0031] In order to reduce the pressure on the clutch actuator, it can also be stipulated that the pressure reducing device is used as a drainage device for discharging the fluid. For this purpose, the hydraulic system advantageously has a storage device for receiving the discharged fluid and / or supplying a sufficient amount of fluid to the cooling device or the clutch actuator.

[0032] In particular, it is stipulated that the first reversing valve is a two-way two-way valve, and a check valve is arranged between the reversing valve and the clutch actuator to prevent the volume flow from the clutch actuator to the first reversing valve.

[0033] In an alternative embodiment, it is provided that the first reversing valve is a two-position three-way valve and the volumetric flow source is a pump capable of operating in opposite directions, wherein the first output side of the pump is fluidly connected to the first reversing valve to achieve a first flow direction, and the second output side of the pump is fluidly connected to a pressure reducing device to achieve a second flow direction. A check valve is provided between the second output side of the pump and the storage device to prevent backflow into the storage device.

[0034] The hydraulic system is preferably designed for a pressure range of up to 10 bar. The hydraulic lines are preferably designed with low leakage. For this purpose, a storage device is provided to receive the returned fluid and form a reservoir for the fluid that is needed again.

[0035] The hydraulic system according to the invention can also have a so-called integral actuator, which includes a control device as a compact structural unit and an electric motor for driving the volumetric flow source. The electric motor is in particular connected to the control device in a control-technical manner such that the control device can control the electric motor according to the volumetric flow source. For this purpose, the electric motor can be integrated in a valve plate, which is part of the integral actuator. In addition, a pressure sensor and the mentioned valves can be installed in the integral actuator 80. Then, preferably, the connection between the control device and the valves to be actuated is realized in a control-technical manner directly on the control device by means of plug-in contacts.

[0036] Furthermore, the hydraulic system can have a clutch device, in particular a disengaging clutch, which is used to transmit torque from the connected internal combustion engine and / or at least one electric motor to the output element. In this case, a clutch actuator of the hydraulic system is provided for actuating the clutch device and is fluidly connected thereto.

[0037] The electric motor is provided as part of a hybrid module to provide torque when delivering electrical energy, thereby driving the vehicle in this way or assisting the connected internal combustion engine, and / or is provided to provide the torque when torque is generated on the electric motor, to operate in a generator-driven mode and provide electrical energy in this way. The torque generated on the electric motor can be generated by the connected internal combustion engine or by the powertrain or wheels of the motor vehicle, so that part of its kinetic energy is converted into electrical energy by means of the electric motor.

[0038] The hybrid module for hybrid drive is accordingly equipped with a clutch device and an internal combustion engine, the torque of which can be directly transmitted to the output element of the motor vehicle powertrain equipped with the clutch device.

[0039] The output element is preferably designed accordingly so that the input element of the transmission or the wheel drive can be connected thereto.

[0040] For this, the actuator can have an integrated electronic control device and / or integrated valves.

[0041] The pressure regulation of the clutch device can be achieved by a clutch actuator and / or by a corresponding valve, which is provided for pressure release.

[0042] Another advantageous embodiment of the hydraulic system according to the invention is that the system comprises a hydraulic parking lock, which can be or has been fluid-connected to a volume flow source via a third reversing valve, so that the hydraulic parking lock can be actuated during the operation of the volume flow source.

[0043] Thus, depending on the operation of the volume flow source and the switching position of the third reversing valve, the rotational movement can be locked in the vehicle powertrain equipped with this hydraulic system.

[0044] The hydraulic parking lock is preferably designed to be locked in the normal state.

[0045] When the motor vehicle and the equipped hydraulic system are operating, a corresponding fluid pressure can be applied, so that pressure is continuously applied to the hydraulic parking lock and it is transferred to the open state and maintained there.

[0046] The third reversing valve is preferably a two-position four-way valve, which is connected to one side of the volume flow source, and an actuating line or a clutch device connected thereto is also provided on this side.

[0047] Another aspect of the invention relates to a drive unit for an electrically driven motor vehicle, in particular for the powertrain of a hybrid motor vehicle, and having a hydraulic system according to the invention, a first electric machine, a second electric machine and an output shaft, which also serves as the transmission input shaft, wherein the rotor of the second electric machine is torsionally connected to the output shaft, and at the same time, by means of a disengaging clutch, the rotor of the first electric machine and an internal combustion engine can be connected or have been connected to the output shaft for torque transmission, the internal combustion engine is connected to a first shaft, and the first shaft is torsionally connected to the rotor of the first electric machine.

[0048] The drive unit is preferably designed as a hybrid module and comprises an input element for torsionally coupling an internal combustion engine, so that the internal combustion engine and the first electric machine are rotationally coupled to each other or can be coupled.

[0049] In particular, it is specified that only one disengaging clutch is included in the drive unit designed as a hybrid module.

[0050] For this purpose, the hydraulic system according to the invention is arranged to cool at least one of the two electric machines and to actuate the clutch device by a clutch actuator.

[0051] For this purpose, in particular, the two electric machines are arranged in series. In a preferred embodiment, it is specified that the rotors or their rotational axes of the two electric machines are coaxially arranged. In addition to cooling the electric machines, the volume flow used for this purpose can also be used to cool the rotary bearings of the drive system.

[0052] The disengaging clutch is a switchable clutch that can be switched from an open state to a closed state and vice versa.

[0053] The drive unit can be designed accordingly such that the first shaft fixedly connected to the rotor of the first motor is arranged radially inside the output shaft fixedly connected to the rotor of the second motor. The first shaft can be designed in sections, i.e., as a hollow shaft extending centrally, on which a torsionally rigid disk hub is locally arranged, which is in turn torsionally rigidly connected to the rotor of the first motor. At this time, the radially inner side of the disengaging clutch can be torsionally rigidly connected to the disk hub on the first motor, and the radially outer side of the disengaging clutch can be connected to the output shaft, which is torsionally rigidly connected to the rotor of the second motor.

[0054] In addition, the drive unit can have a gearbox that is effectively connected to the output shaft of the drive unit, which also serves as the input shaft of the gearbox, so that the torque provided by the output shaft or the rotational movement achieved by the output shaft can be stepped up or down through the gearbox and transmitted to another gearbox unit of the motor vehicle, or can also be directly transmitted to the drive wheels of the motor vehicle.

[0055] The gearbox can comprise or be designed as a differential gearbox. The gearbox can include a first gear that meshes with the external teeth on the output shaft. In this way, the first gear realizes the second transmission stage in the drive unit. At this time, the first gear is torsionally coupled to the transmission shaft of the gearbox, and its external teeth mesh with the input gear of the differential gearbox, thereby realizing the third transmission stage.

[0056] The drive unit can also be designed accordingly such that

[0057] it has a first fluid system and a second fluid system, where the first fluid system is used to enable the circulation of a first liquid through the drive unit to at least partially cool at least one motor, and the second fluid system is used to enable the circulation of a second liquid.

[0058] The first fluid system and the second fluid system are arranged and designed accordingly such that heat can be transferred from the first liquid in the first fluid system to the second liquid in the second fluid system.

[0059] Another embodiment of the present invention is a drive device that has a drive unit according to the present invention and an internal combustion engine, and the internal combustion engine and the rotor of the first motor are torsionally rigidly coupled to each other or can be coupled.

[0060] Such a drive device is advantageously designed accordingly such that the first transmission stage is arranged between the internal combustion engine and the first shaft, which is torsionally rigidly connected to the rotor of the first motor, so as to transmit the rotational speed of the rotational movement achieved by the internal combustion engine to the first shaft.

[0061] At this time, the output element of the internal combustion engine can be a shock absorber unit, or it can also be a clutch for opening and closing the torque transmission path between the internal combustion engine and the drive unit, or it can also be a combination of a shock absorber unit and a clutch.

[0062] In addition, the output element can have an internal gear as a component, which meshes with the external teeth of the first shaft and thus realizes the first transmission stage.

[0063] In another embodiment, the drive device further includes at least one wheel drive shaft, which is connected to the output shaft of the drive unit through a gearbox, so that the rotational motion realized by the output shaft can be transmitted to the wheel drive shaft through the gearbox. Description of the Drawings

[0064] The above invention will be explained in detail below in the context of the relevant technical background with reference to the relevant drawings, where the relevant drawings are used to show advantageous embodiments. The purely schematic drawings do not impose any limitations on the present invention. It should be noted here that the embodiments shown in the drawings are not limited to the dimensions shown. Among them

[0065] Figure 1 : A chart with a torque curve,

[0066] Figure 2 : A speed-time graph, in which the curve of the speed changing with time is plotted,

[0067] Figure 3 : The first embodiment of the hydraulic system according to the present invention,

[0068] Figure 4 : The second embodiment of the hydraulic system according to the present invention,

[0069] Figure 5 : The third embodiment of the hydraulic system according to the present invention,

[0070] Figure 6 : The fourth embodiment of the hydraulic system according to the present invention,

[0071] Figure 7 : The fifth embodiment of the hydraulic system according to the present invention,

[0072] Figure 8 : The sixth embodiment of the hydraulic system according to the present invention,

[0073] Figure 9 : The seventh embodiment of the hydraulic system according to the present invention,

[0074] Figure 10 : Two perspective views of the overall actuator,

[0075] Figure 11 : According to the eighth embodiment of the hydraulic system of the present invention,

[0076] Figure 12 : According to the ninth embodiment of the hydraulic system of the present invention,

[0077] Figure 13 : According to the tenth embodiment of the hydraulic system of the present invention,

[0078] Figure 14 : According to the eleventh embodiment of the hydraulic system of the present invention,

[0079] Figure 15 : A drive unit, with a hydraulic system according to the present invention. Detailed embodiments

[0080] In Figure 1 is shown a hysteresis control, which can be performed using the hydraulic system according to the present invention. As Figure 1 shown, at this time the variation of the torque M over time t is shown. A curve can be seen, which forms a lower threshold 70 after a linear increase. In addition, a second curve is superposed on the linear increase, which represents the upper threshold 71 in each time interval. The lower threshold 70 corresponds to the required clutch torque Mn, and the upper threshold 71 corresponds to the adjusted clutch torque Mr. It can be seen that the torque M is adjusted accordingly over time t, so as to increase the torque conforming to the lower threshold 70 in the shortest time until it reaches the value of the adjusted clutch torque Mr or the upper threshold 71. Then the torque M can drop again, i.e., during the so-called hysteresis time tH. During this hysteresis time tH, the fluid provided by the volume flow device can be used to cool one or more motors.

[0081] Thus, through this control, a differential clutch torque Md is achieved between the adjusted clutch torque Mr and the required clutch torque Mn.

[0082] Especially when viewed together with the Figure 2 shown below, it can be seen that only when it is necessary to increase the torque M above the required clutch torque Mn, i.e., until the upper threshold 71 is reached, is it necessary to operate the volume flow source or pump.

[0083] In Figure 3The basic structure of a hydraulic system 1 according to the present invention is shown. In the embodiment shown here, it includes a clutch actuator element 3 in the form of a so-called CSC (concentric slave cylinder), which is mechanically connected to a clutch device 2 to be actuated. In addition, the hydraulic system 1 includes a cooling line 4, which is fluidly connected to a volume flow source 10 and leads to a device to be cooled, such as an electric motor. Additionally, the hydraulic system 1 includes an actuating line 5, which is also fluidly connected to the volume flow source 10 and leads to the hydraulically actuated clutch actuator element 3. A switching device 21 is arranged in a fluid-technical manner between the volume flow source 10 and the device to be cooled or the clutch actuator element 3. In the embodiment shown here, this device is designed as a first reversing valve 30. The first output side 11 of the volume flow source 10 is connected downstream of the first flow direction 12 implemented by this switching device 21 or the first reversing valve 30 here. In the embodiment shown here, the first reversing valve 30 is a two-position three-way valve. The cooling line 4 is connected to the first output of the first reversing valve 30, while the actuating line 5 is connected to the second output of the first reversing valve 30. On the input side, the volume flow source 10 or the pump is fluidly connected to the storage device 60 through a suction filter 72, so as to supply fluid from the storage device 60 to the cooling line 4 or the actuating line 5 by means of the switching device 21.

[0084] In the flow path between the clutch actuator element 3 and the storage device 60, a second reversing valve 50 is arranged. In the embodiment shown here, this second reversing valve is a two-position two-way valve 52. At this time, the second reversing valve 50 is also designed as a pressure reducing device 51.

[0085] The control device 20 is connected to the volume flow source 10, the first reversing valve 30, and the second reversing valve 50 by means of control technology, so as to actuate or adjust these elements according to the requirements for cooling or actuating the clutch actuator element 3.

[0086] During the operation of the volume flow source 10, it conveys fluid from the storage device 60 to the switching device 21. Depending on the position of the switching device 21, the pumped fluid is either conveyed to the cooling line 4 or conveyed to the clutch actuator element 3 via the actuating line 5 for actuating the clutch device 2. When the clutch actuator element 3 is reset, depending on the position of the second reversing valve 50, the fluid can flow back to the storage device 60 again. It can be seen that thus fluid can be supplied to the electric motor for cooling in turn, or for actuating the clutch actuator element 3. A small amount of volume flow source 10 must be set up in a corresponding manner or relatively little energy must be applied in order to maintain cooling and lubrication in a hybrid drive and ensure the required pressing force for transmitting the required clutch torque.

[0087] The first switching valve 30 shown here is a seat valve which has at least one valve seat in the clutch branch. The second switching valve 50 is preferably closed in the non-energized state, however the invention is not limited in this regard, so that the second switching valve 50 can also be designed as a valve which opens when not energized.

[0088] In Figures 4 - 9 compared with the embodiment shown in Figure 3 a different embodiment or variant of the hydraulic system 1 is shown, so that in the following, the differences of the embodiment shown in Figures 4 - 9 will mainly be considered.

[0089] Especially when integrating the hydraulic system into a transmission, it should be prevented that the suction line idles. This suction line is connected to the volume flow source 10 on the input side. For this purpose, as shown in Figure 4 an additional idle protection part 73 is arranged between the storage device 60 and the volume flow source 10. As shown in Figure 4 the idle protection part 73 can be an integral part of the suction filter 72 below it. As an alternative, the idle protection part 73 can also be directly integrated into the housing surrounding the volume flow source 10, see Figure 5 . This has the advantage of a small number of elements to be assembled.

[0090] In another alternative embodiment of the hydraulic system, as shown in Figure 6 it is provided that a first check valve 40 is arranged in the flow path between the volume flow source 10 and the storage device 60. For example, this first check valve 40 can be a flap check valve.

[0091] Different from Figure 3 the variant shown in Figure 7 an embodiment is shown in which the two switching valves 30, 50 are designed as two-way three-way valves.

[0092] In Figure 8 the embodiment shown, the first switching valve 30 is designed as a two-way three-way valve 31 and the second switching valve 50 is a two-way two-way valve 52. In the flow path between the conversion device 21 and the clutch actuator 3, this valve, in combination with the second check valve 41 as a slide valve, can be realized at low cost. The second switching valve 50 can be designed as a proportional seat valve in order to controllably release the pressure from the clutch actuator 3.

[0093] In Figure 9 the embodiment variant shown, the second switching valve 50 is again designed as a two-way two-way valve 52 and, similarly as in Figure 8As in the embodiments described, there is a second check valve 41. It is also provided here that the volumetric flow source 10 can convey in both directions, so that a second flow direction 14 can be achieved on the second outlet side 13 of the volumetric flow source 10. When the volumetric flow source 10 is operating, in order to achieve a volumetric flow in the first flow direction 12, fluid can be supplied to the cooling line 4 accordingly and thus cooled; and after the switching device 21 is switched, the clutch actuator element 3 is actuated in such a way. When switching the operation of the volumetric flow source 10, it can convey fluid in the second flow direction 14 through the second outlet side 13, so that, depending on the switching position of the second reversing valve 50, a direct supply of fluid to the clutch actuator 3 is ensured. The first check valve 40 prevents the fluid from flowing back into the suction strainer 72 or the storage device 60. In this embodiment, the second reversing valve 50 is preferably hydraulically actuated, so that the electromagnet for actuating the valve can be dispensed with. The second reversing valve 50 is designed as a seat valve, and its piston can be equipped with a seal without thereby increasing the risk of functional failures due to the resulting friction, because the force provided hydraulically is significantly greater than the force required to move the piston and the force that can be provided by an electromagnet.

[0094] Another aspect of the invention lies in the possible compact design of the hydraulic system and the connected units in the overall actuator 80, the overall actuator being shown in Figure 10 two perspective views. The overall actuator 80 includes a control device 20 and a valve plate 81 mechanically connected thereto, in which a motor can be integrated for driving the volumetric flow source. Opposite the control device 20, an adapter plate 82 is provided, on or in which the volumetric flow source 10 can be or has been mechanically connected.

[0095] Furthermore, pressure sensors and the valves mentioned can be installed in the overall actuator 80. The control-technical connection between the control device 20 and the valves to be actuated can be realized directly on the control device 20 by means of plug-in contacts. Such a compact unit can be tested individually in a simple manner and assembled in a simple manner.

[0096] In Figure 11 and 12 other variants of the hydraulic system 1 according to the invention are shown.

[0097] Here, the second reversing valve is dispensed with, and only the first reversing valve 30 and the volumetric flow source 10 need to be provided, which can operate in the reverse direction. Thus in Figure 11 and 12The volume flow source 10 shown in the figure has a first output side 11 and a second output side 13, so that a first flow direction 12 can be realized and a second flow direction 14 can be realized in the opposite direction. Therefore, the volume flow source 10 also has a switching device 21, which can be switched accordingly, so that the fluid can be conveyed to the cooling pipeline 4 or to the actuating pipeline 5 for actuating the clutch actuator 3. In addition, in Figure 11 and Figure 12 the two embodiments shown also include a third check valve 42 and a fourth check valve 43. In this way, the second reversing valve 50 can be omitted, because all functions can be realized when the volume flow source 10 reverses its direction, and there is no need to return the fluid to the storage device 60. For this purpose, the check valves 40, 41, 42, 43 are designed for low pressure drop. In Figure 11 the embodiment shown, the first reversing valve 30 is a so-called shut-off valve, and the clutch actuator 3 for the storage device can be taught by using this shut-off valve.

[0098] In Figure 13 and Figure 14 other embodiments of the hydraulic system variants shown in Figure 11 and Figure 12 are shown.

[0099] Basically, a hydraulic parking lock 90 is added respectively here, and the device is fluid-coupled with the volume flow source 10, that is, through a third reversing valve 20 here.

[0100] The hydraulic parking lock 90 includes a pawl 94, which can engage into the stop teeth 95 of the rotating parts of the drive unit in the case of hydraulic actuation, and the drive unit is equipped with a hydraulic system.

[0101] The hydraulic parking lock 90 includes a piston-cylinder unit 96, which is fluid-coupled with the third reversing valve 92 through a parking lock pipeline 91. For this, the translational movement of the piston of the piston-cylinder unit 96 can be transmitted to the pawl 94 of the hydraulic parking lock 90.

[0102] The hydraulic parking lock 90 is preferably designed to be locked in the normal state.

[0103] When the motor vehicle and the equipped hydraulic system are running, the corresponding fluid pressure can be applied, so that the hydraulic parking lock 90 is continuously pressurized, and it is transferred to the open state and maintained here.

[0104] The third reversing valve 92 is preferably a two-position four-way valve, which is connected to one side of the volume flow source 10, and on this side, the actuating pipeline 5 or the clutch device 2 connected thereto is also arranged.

[0105] Accordingly, a third reversing valve 92 is integrated so that the piston - hydraulic cylinder unit 96 can be emptied into the storage device 60.

[0106] In the actuated position, the piston - hydraulic cylinder unit 96 is connected to the volume flow source 10, thereby actively designing the parking lock 90.

[0107] During this period, the branch of the hydraulic system leading to the clutch device 2 is in the locked position or open towards the storage device 60.

[0108] Once the hydraulic parking lock mechanism 90 engages, this state is maintained by the holding magnet 97. As long as the holding magnet 97 is not energized, the hydraulic parking lock 90 will automatically adjust back to the unlocked state.

[0109] For the controllable engagement of the hydraulic parking lock 90, the volume flow source 10 can first release the load on the holding magnet 97 through the third reversing valve 92 and then controllably output fluid.

[0110] The state of the hydraulic parking lock 90 can be monitored by a stroke sensor.

[0111] Additionally, the hydraulic system can be designed accordingly so that the discharge line connected to the piston - hydraulic cylinder unit 690 is fluid - connected to the cooling line 4, so that in the event of a failure of the holding magnet 97, the hydraulic parking lock 90 can continue to be held open under appropriate pressure conditions by relying on the return pressure of the cooling line 4 and the vehicle can remain drivable.

[0112] In Figure 15 is shown a drive unit 100 for an electrically drivable motor vehicle, in particular for a hybrid motor vehicle powertrain, which has a first electric machine 110 and a second electric machine 120, both electric machines being arranged on a common rotational axis 101. The rotor 111 of the first electric machine 110 is coaxially arranged with the rotational axis 101 and the rotor 121 of the second electric machine 120.

[0113] The two electric machines 110, 120 can be cooled by the hydraulic system 1 according to the invention, or the actuation system 153 can be braked as the clutch actuator 3 by the hydraulic system 1 according to the invention.

[0114] The stator 112 of the first electric machine 110 and the stator 122 of the second electric machine 120 are positioned in the housing 102 of the drive unit 100.

[0115] The rotor 111 of the first electric machine is torsionally connected to the first shaft 130.

[0116] The rotor 121 of the second electric machine 120 is torsionally connected to the output shaft 140, which can also serve as the transmission input shaft.

[0117] Furthermore, the drive unit 100 also includes a disengaging clutch 150 through which the first electric motor 110 and an internal combustion engine can be connected or are connected to the output shaft to achieve torque transmission. The internal combustion engine is connected to the first shaft 130, and the first shaft is torsionally connected to the rotor 111 of the first electric motor 110.

[0118] Therefore, the drive unit according to the present invention can also be used as a series hybrid drive, which has the possibility of directly connecting the connected internal combustion engine to the wheels in a motor vehicle equipped with the internal combustion engine.

[0119] In the embodiment shown here, the first shaft 130 has a two-piece design, that is, it consists of a hollow shaft 132 extending centrally and a disk hub 133 arranged on and torsionally connected to the hollow shaft 132. The disk hub 133 is fixedly connected to the rotor 111 of the first electric motor 110.

[0120] The disk hub 133 forms the radially inner side 151 of the disengaging clutch 150 or is fixedly connected to this input side of the disengaging clutch 150.

[0121] The radially outer side 152 of the disengaging clutch 150 forms the output side of the disengaging clutch 150 and is torsionally connected to the output shaft 140.

[0122] The disengaging clutch 150 is a switchable clutch that can be switched from the open state to the closed state and vice versa. For this purpose, the disengaging clutch 150 is assigned to an actuating system 153.

[0123] Thus, when the disengaging clutch 150 is closed, torque can be transmitted from the first shaft 130 to the output shaft 140 and vice versa.

[0124] Therefore, in the embodiment shown here, it is provided that the two electric motors 110, 120 are arranged in series, and the rotors 111, 121 of the two electric motors 110, 120 or their rotational axes are coaxially arranged.

[0125] At this time, the first shaft 130 or its centrally extending hollow shaft 132 extends radially inside the output shaft 140, so that the structural volume required for the drive unit 100 can generally be reduced.

[0126] Furthermore, the drive unit 100 shown here includes a transmission 160 that is effectively connected to the output shaft 140 of the drive unit 100. The output shaft also serves as the transmission input shaft, so that the torque provided by the output shaft 140 or the rotational movement achieved by the output shaft 140 can be stepped up or down through the transmission 160 and transmitted to another transmission unit of the motor vehicle, or can also be directly transmitted to the drive wheels of the motor vehicle.

[0127] In the embodiment shown here, the transmission 160 includes a differential transmission 170.

[0128] In addition, the transmission 160 includes a first gear 161 that meshes with the external teeth 141 on the output shaft 140. In this way, the first gear 161 realizes the second transmission stage 162 in the drive unit 100. At this time, the first gear 161 is torsionally coupled with the transmission shaft 163 of the transmission 160, and its external teeth 164 mesh with the input gear 171 of the differential transmission 170, thereby realizing the third transmission stage 172.

[0129] In the embodiment of the drive device 200 also shown here, the drive unit 100 is an integral part thereof.

[0130] In addition, the drive device 200 also has an internal combustion engine (not shown here). When connected to the shown interface 210, the internal combustion engine is torsionally coupled to the rotor 111 of the first electric machine 110 through the first shaft 130, or can be coupled in the case where another clutch is interposed.

[0131] The shown drive device 200 is designed accordingly such that a first transmission stage 142 is formed between the interface 210 for the internal combustion engine (not shown here) and the first shaft 130. The first shaft 130 is torsionally connected to the rotor 111 of the first electric machine 110, thereby transmitting the rotational speed of the rotational motion realized by the internal combustion engine or its interface 210 to the first shaft 130.

[0132] For this purpose, an output element 220 of the internal combustion engine is provided, which may have a shock absorber unit 221 or a clutch 222 for opening and closing the torque transmission path between the internal combustion engine and the drive unit 100, or a combination of the shown shock absorber unit 221 and clutch 222.

[0133] In addition, the output element 220 includes an internal gear 223 as an integral part, which meshes with the external teeth 131 of the first shaft 130 and thus realizes the first transmission stage 142.

[0134] It can be seen that in the embodiment shown here, the rotational axis of the output element 220 is laterally offset with respect to the rotational axis 101 of the drive unit 100.

[0135] In this way, the rotational motion generated by the internal combustion engine (not shown here) can be transmitted to the first shaft 130 through the output element 220 and the first transmission stage 142, so that the rotor 111 of the first electric machine 110 located thereon can start to rotate and operate as a generator.

[0136] When the disconnect clutch 150 is closed, the resulting rotational movement can be transmitted from the first shaft 130 to the output shaft 140, and may be enhanced by motor-driven actuation by the first electric machine 110 if necessary. Based on the torsionally rigid connection of the rotor 122 of the second electric machine 120 to the output shaft 140, the torque provided by the second electric machine 120 can likewise be applied to the output shaft 140.

[0137] As an alternative, when the disconnect clutch 150 is open, only the second electric machine 120 can be operated alone to rotate the output shaft 140.

[0138] The rotational movement of the output shaft 140 is transmitted via its external teeth 141 to the first gear 161 of the connected gearbox 160, and in so doing, the second transmission stage 162 is realized.

[0139] The torque or rotational movement is transmitted from the first gear 161 to the transmission shaft 163, from where it is transmitted to the input gear 171 of the differential gearbox 170.

[0140] The torque is transmitted from the differential gearbox 170 to a wheel drive shaft (not shown here), or, if necessary, from another gearbox, in order to increase or reduce the torque or rotational speed.

[0141] By means of the drive device 200 shown, a plurality of driving states can be realized, for example, operating only the internal combustion engine to drive a motor vehicle, or alternatively operating with the second electric machine and / or the first electric machine connected, and, when the internal combustion engine and / or the second electric machine are operating, operating the first electric machine in generator drive mode at the same time, and operating only the second electric machine, or the regenerative operation of the first electric machine and / or the second electric machine.

[0142] Overall, by means of the present invention, a hydraulic system and a drive unit equipped with this system are provided, which ensure the low-cost and efficient operation of at least one electric machine in a minimum structural space, especially in the case of interconnection with an internal combustion engine.

[0143] Explanation of reference numerals

[0144] 1 Hydraulic system 2 Clutch device 3 Clutch actuating element 4 Cooling line 5 Actuating line 10 Volume flow source 11 First output side 12 First flow direction 13 Second output side 14 Second flow direction 20 Control device 21 Conversion device 30 First reversing valve 31 Two-position three-way valve 32 Two-position two-way valve 40 First check valve 41 Second check valve 42 Third check valve 43 Fourth check valve 50 Second reversing valve 51 Pressure reducing device 52 Two-position two-way valve 60 Storage device 70 Lower threshold 71 Upper threshold 72 Suction filter 73 Idle protection part 80 Integral actuating element 81 Valve plate 82 Adapter plate 90 Hydraulic parking lock 91 Parking lock line 92 Third reversing valve 94 Pawl 95 Stop tooth 96 Piston-cylinder unit 97 Holding magnet M Clutch torque Mr Adjusted clutch torque Mn Required clutch torque Md Differential clutch torque n Pump speed t Time tH Hysteresis time 100 Drive unit 101 Axis of rotation 102 Housing 110 First motor 111 Rotor of the first motor 112 Stator of the first motor 120 Second motor 121 Rotor of the second motor 122 Stator of the second motor 130 First shaft 131 External teeth of the first shaft 132 Hollow shaft extending centrally 133 Disk hub 140 Output shaft 141 External teeth of the output shaft 142 First transmission stage 150 Clutch release 151 Radial inner side of the clutch release 152 Radial outer side of the clutch release 153 Braking system 160 Gearbox 161 First gear 162 Second transmission stage 163 Transmission shaft 164 External teeth of the transmission shaft 170 Differential gearbox 171 Input gear 172 Third transmission stage 200 Drive device 210 Internal combustion engine interface 220 Output element 221 Shock absorber unit 222 Clutch 223 Internally meshing gear.

Claims

1. A hydraulic system (1) for supplying fluid to at least one electric motor (110, 120) to cool at least one rotating component in the electric motor (110, 120) and to actuate a clutch device (2), the hydraulic system (1) comprising a volumetric flow source (10), the electric motor (110, 120) to be cooled and a clutch actuator (3) for actuating the clutch device (2), and a switching device (21) for sequentially delivering the fluid volumetric flow from the volumetric flow source (10) to the electric motor (110, 120) or the clutch actuator (3), a hydraulic parking lock (90) which can be fluid-connected or is fluid-connected to the volumetric flow source (10) via a third reversing valve (92) such that the hydraulic parking lock (90) can be actuated during operation of the volumetric flow source (10), the third reversing valve (92) being a two-position four-way valve which is simultaneously connected to one side of the volumetric flow source (10), on which side there is also arranged an actuation line (5) for actuating the clutch actuator (3), the volumetric flow source (10) being a pump which can operate in opposite directions, and the hydraulic parking lock (90) can be actuated according to the operation of the volumetric flow source (10) and the switching position of the third reversing valve (92).

2. The hydraulic system (1) according to claim 1, characterized in that, The hydraulic system (1) comprises a control device (20) which is specifically configured to be able to correspondingly control the switching device (21) so as to sequentially supply the electric motor (110, 120) or the clutch actuator (3).

3. The hydraulic system (1) according to claim 2, characterized in that, The control device (20) is specifically configured such that when the fluid pressure at the clutch actuator (3) drops below a specified lower threshold (70), the switching device (21) switches from cooling the electric motor (110, 120) to supplying the clutch actuator (3); and when the fluid pressure at the clutch actuator (3) rises above a specified higher threshold (71), the switching device (21) switches from supplying the clutch actuator (3) to cooling the electric motor (110, 120).

4. The hydraulic system (1) according to claim 1, characterized in that, The switching device (21) is a first reversing valve (30).

5. The hydraulic system (1) according to claim 4, characterized in that, The hydraulic system (1) has a pressure reducing device (51) for specifically reducing the pressure on the clutch actuator (3), and for this purpose the pressure reducing device (51) is mainly a second reversing valve (50).

6. The hydraulic system (1) according to claim 4, characterized in that, The first reversing valve (30) is a two-position two-way valve (32), and a check valve is arranged between the reversing valve and the clutch actuator (3) to prevent the volumetric flow from the clutch actuator (3) to the first reversing valve (30).

7. The hydraulic system (1) according to claim 5, characterized in that, The first switching valve (30) is a two-position three-way valve (31), and the volumetric flow rate source (10) is a pump capable of operating in opposite directions. The first output side (11) of the pump is fluidly connected to the first switching valve (30) to achieve a first flow direction (12), and the second output side (13) of the pump is fluidly connected to the pressure reducing device (51) to achieve a second flow direction (14). Moreover, a check valve is provided between the second output side (13) of the pump and the storage device (60) to prevent backflow into the storage device (60).

8. The hydraulic system (1) according to any one of claims 2 to 7, characterized in that, The hydraulic system includes an integral actuator (80), which is a compact structural unit including a control device (20) and an electric motor for driving the volumetric flow rate source (10).

9. The hydraulic system (1) according to any one of claims 2 to 7, characterized in that, The hydraulic system (1) has a clutch device (2), which is a disengaging clutch. This device is used to transmit torque from the connected internal combustion engine and / or at least one electric motor (110, 120) to the output element (220). At this time, a clutch actuator (3) of the hydraulic system (1) is provided for actuating the clutch device (2), and a fluid connection is established therewith.

10. A drive unit (100) for an electrically driven motor vehicle powertrain, including the hydraulic system (1) according to claim 1, a first electric motor (110), a second electric motor (120), and an output shaft (140). The rotor (121) of the second electric motor (120) is torsionally connected to the output shaft (140). At the same time, by using a clutch device (2) designed as a disengaging clutch, the rotor (111) of the first electric motor (110) can be connected or has been connected to the output shaft (140) to achieve torque transmission.

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