Hydraulic system, electrically drivable drive train of a motor vehicle and hybrid module

Abstract

A hydraulic system, an electrically drivable drive train of a motor vehicle and a hybrid module. The invention relates to a hydraulic system comprising a hydraulic storage container, a first hydraulic pump and a second hydraulic pump, the suction sides of the first hydraulic pump and of the second hydraulic pump being connected in hydraulic correspondence with the hydraulic storage container via a first suction line and a second suction line, the hydraulic system having a filter unit which is connected in hydraulic correspondence on one side with the hydraulic storage container and on the other side with the first suction line and the second suction line, a bypass valve being provided on the first suction line, the bypass valve being switchable into a closed position in a first operating temperature range of the hydraulic fluid and into an open position in a second operating temperature range of the hydraulic fluid, and a hydraulic connection line being provided between the first suction line and the second suction line, the hydraulic connection line hydraulically connecting the outlet of the first suction filter with the first suction line.

Description

Technical Field

[0001] This invention relates to a hydraulic system, particularly for an electrically driven drive system of a motor vehicle. The hydraulic system includes a hydraulic reservoir for storing hydraulic fluid, a first hydraulic pump, and a second hydraulic pump. The suction side of the first hydraulic pump is hydraulically connected to the hydraulic reservoir via a first suction line, and the suction side of the second hydraulic pump is hydraulically connected to the hydraulic reservoir via a second suction line. The hydraulic system also includes a filter unit, which is hydraulically connected to the hydraulic reservoir on one side and to the first and second suction lines on the other side. Hydraulic fluid can be transported from the hydraulic reservoir through the filter unit and the first suction line by the first hydraulic pump, and from the hydraulic reservoir through the filter unit and the second suction line by the second hydraulic pump. The filter unit has a first suction filter, which is hydraulically connected to the second suction line on one side and to the hydraulic reservoir on the other side. A filter medium that can be passed through by the hydraulic fluid is arranged within the first suction filter. This invention also relates to an electrically driven drive system of a motor vehicle and a hybrid powertrain module. Background Technology

[0002] Electric motors are increasingly being used in motor vehicles to provide an alternative to internal combustion engines that require fossil fuels. Significant efforts have been made to improve the everyday usability of electric drives and to provide users with typical driving comfort.

[0003] A detailed description of the electric drive unit can be found in an article titled "Highly Integrated and Flexible Electric Drive Unit for Electric Vehicles" (Erik Schneider, Frank Fickl, Bernd Cebulski und Jens Liebold, pp. 360-365, published May 2011) in ATZ 113. This article describes a drive unit for a vehicle axle, comprising an electric motor arranged concentrically and coaxially with a bevel gear differential. A switchable two-speed planetary gear set is positioned between the electric motor and the bevel gear differential in the powertrain, also coaxially with either the electric motor or the bevel gear differential or the spur gear differential. The drive unit's complex construction and the use of a switchable two-speed planetary gear set allow for a good trade-off between climbing ability, acceleration, and energy consumption. This type of drive unit is also known as an electric axle unit or an electrically driven drive system.

[0004] In addition to purely electric drive systems, hybrid drive systems are also known. Such hybrid vehicle drive systems typically include a combination of an internal combustion engine and an electric motor, and can operate in pure electric mode, for example, in densely populated areas, especially during long-distance driving, while maintaining sufficient effective range and availability. They can also be driven simultaneously by both an internal combustion engine and an electric motor under specific operating conditions.

[0005] In pure electric and hybrid drive systems, hydraulic systems with hydraulic fluid are used to cool existing motors, clutches and / or transmissions, as well as for hydraulically actuated clutches and / or transmissions.

[0006] Due to operating conditions, such hydraulic systems may become contaminated with hydraulic fluid containing solid particles during operation, for example, due to wear. Therefore, filter units that can filter solid particles from hydraulic fluid are known in principle by existing technology.

[0007] To avoid excessive pressure loss in such filter units, especially at relatively low operating temperatures and when the hydraulic fluid is of high viscosity, bypass valves are known in principle in the prior art. Pressure loss occurs particularly when low-viscosity hydraulic fluids, such as hydraulic oil, are drawn through the filter medium. Here, the pore size of the filter medium is essentially determined by two conflicting parameters: the pressure loss of the filter medium and the separation rate.

[0008] It is also known to provide a bypass valve for the filter unit described at the beginning, so as to ensure the flow of hydraulic medium when the flow resistance at the filter unit is such that an increase is not permissible. In this case, opening the bypass valve ensures the supply of hydraulic fluid to the hydraulic system. Summary of the Invention

[0009] The object of this invention is to provide a hydraulic system for an electrically driven drive system with improved service life. Particularly, the object of this invention is also to achieve a hydraulic system for an electrically driven drive system that exhibits better filter separation efficiency, especially during cold starts. The object of this invention is also to provide electrically driven vehicle drive systems and hybrid power modules with improved service life.

[0010] This objective is achieved through a hydraulic system, particularly for electrically driven drive systems of motor vehicles, comprising a hydraulic reservoir for storing hydraulic fluid, a first hydraulic pump, and a second hydraulic pump. The suction side of the first hydraulic pump is hydraulically connected to the hydraulic reservoir via a first suction line, and the suction side of the second hydraulic pump is hydraulically connected to the hydraulic reservoir via a second suction line. The hydraulic system also includes a filter unit, one side of which is hydraulically connected to the hydraulic reservoir and the other side to the first and second suction lines. This allows hydraulic fluid to be transported from the hydraulic reservoir through the filter unit and the first suction line by means of the first hydraulic pump, and hydraulic fluid to be transported by means of the second hydraulic pump. The fluid is conveyed from the hydraulic storage container through a filtration unit and a second suction line. The filtration unit has a first suction filter, one side of which is hydraulically connected to the second suction line and the other side is connected to the hydraulic storage container. A filter medium that can be passed through the hydraulic fluid is provided in the first suction filter. A bypass valve is provided in or on the first suction line. The bypass valve can be switched to a closed position within a first operating temperature range of the hydraulic fluid and to an open position within a second operating temperature range of the hydraulic fluid. A hydraulic connection line is provided between the first suction line and the second suction line, which hydraulically connects the outlet of the first suction filter to the first suction line.

[0011] Therefore, the hydraulic system according to the invention includes two pumps that draw hydraulic fluid from a common hydraulic reservoir. In conventional filtration units, during, for example, the cold start phase of an electrically driven drive system equipped with a hydraulic system, the temporary opening of a bypass valve when the hydraulic fluid viscosity is high only allows the unfiltered hydraulic fluid to be delivered to the two pumps through a filter medium, which increases the probability of hydraulic system failure.

[0012] According to the invention, the hydraulic system is configured such that at least partially filtered hydraulic fluid is present in the second suction line even when the bypass valve is open. This at least increases the service life of the second pump, or the hydraulic components arranged on the pressure side of the second pump, which are sensitive to contaminated hydraulic fluid, while the first pump, which is less sensitive to the second pump, is supplied with unfiltered or only slightly filtered hydraulic fluid. Thus, one of the two pumps delivers hydraulic fluid, such as oil, to a system that has higher requirements for oil purity than the other system.

[0013] According to the present invention, the bypass valve is capable of filtering hydraulic fluid in a temperature-dependent manner. Therefore, the filter medium can be particularly suitable for use at normal operating temperatures, where a lower filtration rate is considered, especially during the cold start phase, due to pressure losses determined by the viscosity of the filter unit.

[0014] Preferably, the filter unit is at least partially arranged within the hydraulic reservoir, thereby achieving a particularly compact structural unit comprising the filter unit and the hydraulic reservoir. The hydraulic reservoir is particularly preferably configured as an oil sump. The filter unit is specifically used for filtering solid components from the hydraulic fluid.

[0015] The suction filter can be configured as a component of a hydraulic storage container, a line filter in a suction line, or located close to the inlet of a suction line.

[0016] First, the various elements of the subject matter claimed in this invention are described in the order of the claims. A particularly preferred design of the subject matter of this invention is described below.

[0017] The motor vehicle in this application refers to a land-based vehicle that moves by mechanical power. Motor vehicles may be selected from, for example, passenger cars (PKW), trucks (LKW), small motorcycles, light motor vehicles, motorcycles, motor buses (KOM), or tractor-trailers. Hybrid electric vehicles, also known as hybrid electric vehicles (HEVs), are electric vehicles driven by at least one electric motor and another energy converter, and obtain energy from their electrical storage (Akku) and additional fuel carried on board.

[0018] The hydraulic system according to the invention is particularly suitable for electrically driven motor vehicle drive systems. However, it is also conceivable in principle to use the hydraulic system in conventional internal combustion engine-driven drive systems of motor vehicles.

[0019] In this application, the drive system of a motor vehicle is understood as all components in the motor vehicle that generate power for driving the motor vehicle and transmit it to the road via the wheels.

[0020] Hydraulic fluids in motor vehicle hydraulic separation systems serve functions such as transmitting pressure energy with minimal loss within the vehicle's clutch system. In addition to this primary function, hydraulic fluids also provide lubrication, cooling, and corrosion protection for moving parts and the metal surfaces of the hydraulic system. Furthermore, hydraulic fluids can remove contaminants (e.g., those generated by wear), water, and air, as well as heat generated by losses.

[0021] The hydraulic system according to the invention also includes a hydraulic reservoir for containing and storing hydraulic fluid. The hydraulic reservoir can also be configured as an oil sump for containing and storing hydraulic oil. The hydraulic reservoir can also be constructed as an oil pan in an internal combustion engine, electric motor, transmission, wet clutch, etc.

[0022] According to the advantageous design of the invention, the first suction filter, bypass valve and / or connecting pipeline can be arranged within the filtration unit, thereby achieving a very compact unit structure.

[0023] According to another preferred improvement of the invention, a second suction filter may be provided in the first suction line or between the bypass valve and the hydraulic storage container, and a filter medium capable of being flowed through the hydraulic fluid may be arranged within the second suction filter. This allows for better filtration when the bypass valve is open. Particularly preferred here is that the second suction filter has lower pressure loss than the first suction filter, especially in the cold start operating range.

[0024] Furthermore, according to an equally advantageous design of the invention, the connecting lines are configured such that, in the open position of the bypass valve, hydraulic fluid flows from the second suction line to the first suction line. To achieve this design, it is particularly preferable that the volumetric flow rate of the hydraulic fluid in the second suction line is greater than that in the first suction line. Alternatively or additionally, the pressure drops in the suction lines may also be different. The advantage of this design is that, although the bypass valve is open, only a portion of the total hydraulic fluid flow is delivered unfiltered through the bypass valve.

[0025] According to another particularly preferred embodiment of the invention, the hydraulic flow resistance of the connecting pipe and the second suction pipe can be made less than the hydraulic flow resistance of the first suction pipe.

[0026] Furthermore, the present invention can be improved by selecting a first operating temperature range for the hydraulic fluid as a cold start operating range and a second operating temperature range for the hydraulic fluid as a normal operating range. Preferably, for example, the first operating temperature range has a temperature lower than 0°C as an upper temperature limit, and the second operating temperature range includes a temperature range greater than or equal to 0°C to 120°C.

[0027] In another preferred embodiment of the invention, the first and second pumps can be coupled to each other in terms of drive, so that they draw hydraulic fluid synchronously. It is also advantageous to improve the invention in such a way that the first and second pumps are driven by a common pump motor. The advantage of this is that only one pump motor is needed, which contributes to a compact and cost-effective design.

[0028] Another preferred design according to the subject matter of the invention allows the first pump, the second pump, and the pump motor to form a structural unit, which also achieves a compact structure and better installation friendliness.

[0029] The object of the present invention is also achieved by an electrically driven drive system for a motor vehicle, the drive system including a motor and a transmission assembly, wherein the motor and the transmission assembly form a structural unit, the drive system including a hydraulic system according to any one of claims 1-8, wherein the pressure side of a first pump is coupled to a cooling system and the pressure side of a second pump is coupled to an actuation system.

[0030] Preferably, the hydraulic storage container forms a structural unit with the electrically driven drive system of the motor vehicle. In particular, the hydraulic storage container can also be configured as the oil pan of the electrically driven drive system of the motor vehicle.

[0031] The electric axle drive system of a motor vehicle includes a motor and a transmission, wherein the motor and transmission form a structural unit. In particular, the motor and transmission can be arranged in a common drive system housing. Alternatively, the motor can have an engine housing and the transmission a transmission housing, wherein the structural unit is created by fixing the transmission relative to the motor. This structural unit is sometimes also referred to as an E-axle assembly.

[0032] An electric motor is used to convert electrical energy into mechanical energy and / or vice versa, and typically includes a fixed component called a stator, stator segments or armature, and a component called a rotor or armature that is movably arranged relative to the fixed component.

[0033] Preferably, the electrical mechanism constitutes a rotating electric motor. Particularly preferred is that the motor is configured as a radial-flow motor or an axial-flow motor. In the case of a radial-flow motor, the magnetic field lines constructed in the gap between the rotor and the stator extend in the radial direction, while in the case of an axial-flow motor, the magnetic field lines constructed in the gap between the rotor and the stator extend in the axial direction.

[0034] Electric motors are particularly used in the drive systems of hybrid or fully electric vehicles. Specifically, the size of the motor is determined such that the vehicle speed can reach greater than 50 km / h, preferably greater than 80 km / h, and especially greater than 100 km / h. Particularly preferably, the motor has a power output greater than 30 kW, preferably greater than 50 kW, and especially greater than 70 kW. Even more preferably, the motor provides a speed greater than 5000 U / min, particularly preferably greater than 10000 U / min, and very particularly preferably greater than 12500 U / min.

[0035] The object of the present invention is also achieved by a hybrid power module for a drive system of a motor vehicle, wherein the hybrid power module is arranged in the drive system between the internal combustion engine and the transmission of the motor vehicle, the hybrid power module includes an electric motor that can be coupled into and out of the drive system of the motor vehicle, and the hybrid power module includes a hydraulic system according to any one of claims 1-8, wherein the pressure side of a first pump is coupled to a cooling system and the pressure side of a second pump is coupled to an actuation system.

[0036] In a hybrid powertrain module, the structural and functional components of the hybrid drive system can be spatially and / or structurally combined and pre-assembled, allowing the hybrid powertrain module to be integrated into the drive system of a motor vehicle in a particularly simple manner. Specifically, a motor and clutch system can be present in the hybrid powertrain module, especially a clutch system with a disengagement clutch for engaging the motor into the drive system and / or disengaging the motor from the drive system.

[0037] Based on the point of contact of the electric motor in the drive system, hybrid power modules can be classified into the following categories: P0-P5:

[0038] P0: The electric motor is positioned before the internal combustion engine and coupled to the engine, for example, via a drive belt. In this arrangement, the electric motor is sometimes also referred to as a belt starter generator (RSG).

[0039] P1: The electric motor is positioned directly after the internal combustion engine, close to ground. This arrangement allows the motor to be fixed to the crankshaft, for example, before the starting clutch.

[0040] P2: The electric motor is located between the disengagement clutch and the starting clutch, which is usually referred to as K0, but in the vehicle's drivetrain, before the transmission.

[0041] P3: The electric motor is located in the vehicle's transmission and / or transmission output shaft.

[0042] P4: The electric motor is mounted on an existing or separate axle (this is also known as an electrically driven drive system), and

[0043] P5: The electric motor is located on or in the wheel, for example as a wheel-side engine. Attached Figure Description

[0044] The present invention will now be described in detail with reference to the accompanying drawings, without being limited to the general concept of the invention.

[0045] The attached image is as follows:

[0046] Figure 1 The hydraulic system according to the present invention is shown in the block diagram.

[0047] Figure 2 The filter unit, which has a closed bypass valve, is shown in the block diagram.

[0048] Figure 3 The filter unit is shown in the block diagram, which has an open bypass valve, and

[0049] Figure 4 The block diagram illustrates motor vehicles with drive systems that are both fully electric and hybrid. Detailed Implementation

[0050] Figure 1The hydraulic system 1 is shown for an electrically driven drive system 2 for a motor vehicle 3, which, as in... Figure 4 As shown in the example.

[0051] The hydraulic system 1 includes a hydraulic reservoir 4 configured as an oil sump for storing hydraulic fluid 5, a first hydraulic pump 6, and a second hydraulic pump 7, wherein the suction side of the first hydraulic pump 6 is hydraulically connected to the hydraulic reservoir 4 via a first suction line 8 and the suction side of the second hydraulic pump 7 is hydraulically connected via a second suction line 9. The first hydraulic pump 6 and the second hydraulic pump 7 are coupled to each other in terms of drive, such that hydraulic fluid 5 is drawn synchronously in the first suction line 8 and the second suction line 9. The first hydraulic pump 6 and the second hydraulic pump 7 are driven by a common pump motor (not shown).

[0052] The hydraulic system 1 also has a filter unit 10, one side of which is hydraulically connected to the hydraulic storage container 4 and the other side is connected to the first suction line 8 and the second suction line 9, so that the hydraulic fluid 5 can be transported from the hydraulic storage container 4 through the filter unit 10 and the first suction line 8 by means of the first hydraulic pump 6, and the hydraulic fluid 5 can be transported from the hydraulic storage container 4 through the filter unit 10 and the second suction line 9 by means of the second hydraulic pump 7.

[0053] The filtration unit 10 also has a first suction filter 14, one side of which is hydraulically connected to the second suction line 9 and the other side is connected to the hydraulic storage container 4. The first suction filter 14 contains a filter medium 11 that can be passed through the hydraulic fluid 5, and the filter medium is used to filter out solids from the hydraulic fluid 5.

[0054] A bypass valve 12 is provided in the first suction line 8. The bypass valve can be switched to the closed position within the first operating temperature range of the hydraulic fluid 5 and to the open position within the second operating temperature range of the hydraulic fluid 5.

[0055] In addition, a hydraulic connection pipe 13 is provided between the first suction pipe 8 and the second suction pipe 9, which hydraulically connects the outlet of the first suction filter 14 to the first suction pipe 8.

[0056] exist Figure 1 In the illustrated embodiment, the first suction filter 14, the bypass valve 12, and the connecting pipe 13 are arranged inside the filter unit 10.

[0057] exist Figure 1 In one embodiment, a second suction filter 15 is further provided in the first suction line 8 between the bypass valve 12 and the hydraulic storage container 4. The second suction filter 15 contains a filter medium 16 that can be passed through by the hydraulic fluid 5. In this invention... Figure 2-3 The design shown does not include a second suction filter 15.

[0058] The following is based on Figure 2-3 Describe in detail how the hydraulic system works.

[0059] Figure 3 The block diagram shows the filter unit 10 and the open bypass valve 12, while Figure 2 The filter unit 10 and the closed bypass valve 12 are shown.

[0060] exist Figure 3 In the illustrated hydraulic system 1, during its cold start operating range, two hydraulic pumps 6 and 7 simultaneously deliver hydraulic fluid 5 from the hydraulic storage container 4 through the filter unit 10. The filter unit 10 has an inlet line (not shown in detail) through which the hydraulic fluid 5 is drawn from the hydraulic storage container 4 into the filter unit 10. Because the bypass valve 12 is in its open operating position, the volumetric flow of the hydraulic fluid 5 entering the filter unit 10 is split, with a second volumetric flow of the hydraulic fluid 5 bypassing the filter medium 11 of the first suction filter 14 and entering the first suction line 8, while the first volumetric flow flows into the second suction line 9 after passing through the filter medium 11 of the first suction filter 14.

[0061] The dotted fillings of the arrows indicating the flow direction of hydraulic fluid 5 represent solid particles, dirt, and impurities in hydraulic fluid 5.

[0062] As clearly shown in the diagram, the portion of the hydraulic fluid 5 flowing through the bypass valve 12 is unfiltered, and thus its solid particulate impurities are essentially equivalent to those of the unfiltered hydraulic fluid 5 in the hydraulic storage container 4. The volumetric flow portion of the hydraulic fluid 5 drawn through the filter medium 11 is filtered, and solids are removed from the hydraulic fluid 5 before this volumetric flow portion enters the second suction line 9.

[0063] Connecting pipe 13 connects the second suction pipe 9 to the first suction pipe 8 after the bypass valve 12 along the suction direction after the filter medium 11. Based on the design and configuration of connecting pipe 12, filter medium 11, second suction pipe 9, first suction pipe 8, and hydraulic pumps 6 and 7, three different operating modes of hydraulic system 1 can be set.

[0064] In the first operating mode, hydraulic fluid 5 flows from the second suction line 9 through the connecting line 13 to the first suction line 8, wherein the unfiltered volumetric flow of hydraulic fluid 5 is mixed with the filtered volumetric flow. This dilution reduces the amount of solid impurities in the hydraulic fluid 5 in the first suction line 8.

[0065] In a second possible operating mode, hydraulic fluid 5 flows from the first suction line 8 through the connecting line 13 to the second suction line 9, wherein the unfiltered volumetric flow of hydraulic fluid 5 is mixed with the filtered volumetric flow. This allows, for example, a higher volumetric flow of hydraulic fluid 5 in the second suction line 9, but with fewer solid impurities in the hydraulic fluid 5.

[0066] Finally, it can be considered that in the third operating mode, there is no volumetric flow of hydraulic fluid 5 through the connecting pipeline.

[0067] exist Figure 3 In this configuration, the first operating temperature range of the hydraulic fluid 5 is within its cold start operating range with the bypass valve 12 open. If the hydraulic fluid 5 reaches the second operating temperature range within its normal operating range, the bypass valve 12 closes. This state is... Figure 2 As shown in the image.

[0068] exist Figure 2 As can be seen, no more hydraulic fluid 5 flows through the bypass valve 12. All the hydraulic fluid 5 flowing from the hydraulic storage container 4 is drawn through the filter medium 11 and, after filtration, distributed to the second suction line 9 and the first suction line 8 via the connecting line 13.

[0069] Figure 4 The lower half of the schematic diagram shows an electrically driven drive system 2 of a motor vehicle 3, the drive system including a motor and a transmission assembly, wherein the motor and the transmission assembly form a structural unit, the structural unit including a hydraulic system 1 according to any one of claims 1-8, wherein the pressure side of a first pump 6 is coupled to a cooling system, particularly for the motor and / or transmission, and the pressure side of a second pump 7 is coupled to an actuation system, for example, for switching hydraulic valves.

[0070] Figure 4 The upper schematic diagram also shows a hybrid power module 17 for the drive system 2 of the motor vehicle 3, wherein the hybrid power module 17 is arranged in the drive system 2 between the internal combustion engine and the transmission of the motor vehicle 3, the hybrid power module includes an electric motor 3, which can be coupled into and decoupled from the drive system 2 of the motor vehicle 3, and the hybrid power module includes a hydraulic system 1 according to any one of claims 1-8, wherein the pressure side of the first pump 6 is coupled to a cooling system, particularly for the electric motor and / or the transmission, and the pressure side of the second pump 7 is coupled to an actuation system, for example, for switching hydraulic valves.

[0071] This invention is not limited to the embodiments shown in the accompanying drawings. Therefore, the foregoing description is not restrictive but rather explanatory. The following claims should be understood to include the features mentioned in at least one embodiment of the invention. This does not exclude the presence of other features. If the claims and the foregoing description define "first" and "second" features, this wording is used to distinguish two features of the same type, rather than to determine their priority.

[0072] List of reference numerals

[0073] 1. Hydraulic System

[0074] 2. Drive System

[0075] 3 Motor vehicles

[0076] 4. Hydraulic storage container

[0077] 5. Hydraulic fluid

[0078] 6 First hydraulic pump

[0079] 7 Second hydraulic pump

[0080] 8 First suction line

[0081] 9 Second suction line

[0082] 10 Filter Units

[0083] 11 Filter Media

[0084] 12 Bypass valve

[0085] 13 Connecting pipes

[0086] 14. Suction Filter

[0087] 15. Suction Filter

[0088] 16 Filter Media

[0089] 17 Hybrid Power Module

Claims

1. A hydraulic system (1) for an electrically driven drive system (2) of a motor vehicle (3), said hydraulic system comprising: Hydraulic storage container (4) for storing hydraulic fluid (5) and First hydraulic pump (6) and Second hydraulic pump (7) The first hydraulic pump (6) is hydraulically connected to the hydraulic storage container (4) via a first suction pipe (8) and the second hydraulic pump (7) is hydraulically connected to the hydraulic storage container (4) via a second suction pipe (9). The hydraulic system (1) also includes a filter unit (10), which is hydraulically connected to the hydraulic storage container (4) on one side. On the other side, it is connected to the first suction line (8) and the second suction line (9) respectively. Thus, the first hydraulic pump (6) can deliver hydraulic fluid (5) from the hydraulic storage container (4) through the filter unit (10) and the first suction line (8), and the second hydraulic pump (7) can deliver hydraulic fluid (5) from the hydraulic storage container (4) through the filter unit (10) and the second suction line (9). The filtration unit (10) includes a first suction filter (14), one side of which is hydraulically connected to the second suction pipe (9) and the other side is connected to the hydraulic storage container (4). Furthermore, a filter medium (11) that can be flowed by hydraulic fluid (5) is provided in the first suction filter (14). Its features are, A bypass valve (12) is provided on or in the first suction line (8). The bypass valve can be switched to a closed position within the first operating temperature range of the hydraulic fluid (5) and to an open position within the second operating temperature range of the hydraulic fluid (5). Furthermore, a hydraulic connection pipe (13) is provided between the first suction pipe (8) and the second suction pipe (9), the hydraulic connection pipe causing the outlet of the first suction filter (14) to be hydraulically connected to the first suction pipe (8).

2. The hydraulic system (1) according to claim 1, characterized in that, The first suction filter (14), the bypass valve (12) and / or the hydraulic connection line (13) are arranged inside the filter unit (10).

3. The hydraulic system (1) according to claim 2, characterized in that, A second suction filter (15) is provided on or in the first suction line (8) between the bypass valve (12) and the hydraulic storage container (4), and a filter medium (16) that can be flowed by the hydraulic fluid (5) is arranged in the second suction filter (15).

4. The hydraulic system (1) according to claim 1, characterized in that, The hydraulic connection line (13) is configured such that when the bypass valve (12) is in the open position, hydraulic fluid (5) flows from the second suction line (9) to the first suction line (8).

5. The hydraulic system (1) according to any one of the preceding claims, characterized in that, The hydraulic flow resistance of the hydraulic connection pipeline (13) and the second suction pipeline (9) is less than the hydraulic flow resistance of the first suction pipeline (8).

6. The hydraulic system (1) according to any one of claims 1 to 4, characterized in that, The first operating temperature range of the hydraulic fluid (5) is selected as the cold start operating range, and the second operating temperature range of the hydraulic fluid (5) is selected as the normal operating range.

7. The hydraulic system (1) according to any one of claims 1 to 4, characterized in that, The first hydraulic pump (6) and the second hydraulic pump (7) are coupled to each other in terms of drive, so that they draw hydraulic fluid (5) synchronously.

8. The hydraulic system (1) according to any one of claims 1 to 4, characterized in that, The first hydraulic pump (6) and the second hydraulic pump (7) are driven by a common pump motor.

9. An electrically driven drive system (2) of a motor vehicle (3), said drive system comprising a motor and a transmission assembly, wherein, The motor and the transmission assembly form a structural unit, and the drive system includes a hydraulic system (1) according to any one of claims 1-8, wherein the pressure side of the first pump (6) is coupled to a cooling system and the pressure side of the second pump (7) is coupled to an actuation system.

10. A hybrid power module for use in the drive system (2) of a motor vehicle (3), wherein, The hybrid power module is arranged in the drive system (2) between the internal combustion engine and the vehicle transmission of the motor vehicle (3), the hybrid power module includes an electric motor that can be connected and disconnected from the drive system (2) of the motor vehicle (3), and the hybrid power module includes a hydraulic system (1) according to any one of claims 1-8, wherein the pressure side of the first pump (6) is coupled to the cooling system and the pressure side of the second pump (7) is coupled to the actuation system.

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