Valve unit for a vehicle's oil supply system

Abstract

A valve unit 20 for an oil supply system 1 of an electric drive train of a vehicle is proposed, comprising a valve housing 21 which has at least one pump port 22a for connecting a pump unit 11, an actuating port 23 for connecting a hydraulic actuator 9 and a supply port 24 for connecting an oil circuit 6, with a valve spool 27 which is movable within the valve housing 21 in the axial direction with respect to a principal axis 101 between a basic position G, an actuating position B and a supply position V, wherein in the actuating position B the pump port 22a is connected to the actuating port 23 and in the supply position V the pump port 22a is connected to the supply port 24, wherein the valve housing 21 has a tank port 25 for connection to an oil tank 12,wherein in the basic position G the pump connection 22a is connected to the supply connection 24 and at the same time the actuation connection 23 is connected to the tank connection 25.

Description

[0001] The invention relates to a valve unit for an oil supply system of an electric powertrain of a vehicle with the features of the preamble of claim 1. Furthermore, the invention relates to an oil supply system with the valve unit and a method for controlling the valve unit and / or the oil supply system.

[0002] Directional control valves with multiple ports and switching positions are known for regulating the flow of fluids to actuators, such as cylinders and motors, in hydraulic and pneumatic control systems. Furthermore, hydraulic systems are known for actuating hydraulic consumers, cooling heat sources, and / or lubricating components within a motor vehicle's powertrain, where the use of a directional control valve enables the use of a common pressure source.

[0003] For example, DE 10 2021 104 241 B3 discloses a hydraulic arrangement for actuating hydraulic consumers and for cooling heat sources and / or lubricating components, in particular within a drive train of a motor vehicle, comprising a reversing pump by means of which a hydraulic medium can be conveyed in opposite directions, and the reversing pump has a first pump port and a second pump port, wherein the hydraulic arrangement includes an active valve device, wherein the active valve device is configured as a 6 / 2-way valve.

[0004] The invention aims to create a valve unit of the type mentioned above, which is characterized by the simple integration of a hydraulic actuator, in particular a disconnect unit, into an oil supply system of a drive train.

[0005] This problem is solved according to the invention by a valve unit with the features of claim 1, an oil supply system with the features of claim 11, and a method with the features of claim 15. Advantageous embodiments will become apparent from the dependent claims, the drawings, and / or the description.

[0006] The invention relates to a valve unit designed and / or suitable for an oil supply system of an electric drive train of a vehicle. In particular, the valve unit serves to selectively switch or control a pressure source between at least two hydraulic consumers. Preferably, the valve unit is designed as a directional control valve.

[0007] The valve unit comprises a valve housing which has at least one pump port for connecting a pump unit, one actuating port for connecting a hydraulic actuator, and one supply port for connecting an oil circuit. The pump port is specifically a pressure port to which oil is supplied under pressure. The actuating port and the supply port are specifically working ports from which the oil is discharged towards the respective consumer, in particular the hydraulic actuator or the oil circuit. In principle, the pump port, the supply port, and the actuating port can be located at any point on the housing. However, preferably the pump port, the supply port, and the actuating port, or preferably all ports, are arranged on a common side of the valve housing.

[0008] The valve unit also includes a valve spool which is axially movable within the valve housing between a home position, an actuated position, and a supply position with respect to a main axis. In particular, the valve spool serves to control the flow of oil within the valve unit, preferably to connect or disconnect different ports. Preferably, the valve spool is arranged to be longitudinally movable within a valve chamber, preferably a bore in the valve housing that extends coaxially with the main axis. The main axis is preferably defined by a longitudinal axis of the valve spool.

[0009] In the actuating position, the pump connection is connected to the actuating port, and in the supply position, the pump connection is connected to the supply port, preferably fluidically. In other words, in the actuating position, the pump unit delivers the oil to the hydraulic actuator, and in the supply position, it delivers it to the oil circuit. Preferably, the pump connection is fluidically separated from the supply port in the actuating position and fluidically separated from the actuating port in the supply position. The hydraulic actuator preferably serves to actuate a coupling device. A "normally closed" coupling device is particularly preferred, meaning that the coupling device is closed when depressurized and is open when pressurized. The coupling device can be designed as a positive-locking coupling, preferably a sliding sleeve or claw.The coupling device preferably serves to actuate a disconnect unit, which separates the mechanical connection of an electric machine within a drive train. Preferably, the oil circuit serves to cool and / or lubricate one or more drive and / or transmission components, e.g., electric machine, gears, bearings, etc. Particularly preferably, the oil circuit has at least one oil supply point from which the oil can be specifically supplied to a drive component requiring cooling and / or lubrication. For example, the oil circuit can be suitable and / or configured for dry sump lubrication or, alternatively, for wet sump lubrication.

[0010] Within the scope of the invention, it is proposed that the valve housing has a tank connection for connection to an oil tank, wherein, in the home position, the pump connection is connected to the supply connection and, at the same time, the actuating connection is connected to the tank connection. In other words, in the home position, the pump circulates the oil in the oil circuit, with the oil in the hydraulic actuator simultaneously being discharged into the oil tank. In particular, in the home position, the hydraulic actuator is emptied and / or vented into the oil tank, while the oil circuit is simultaneously supplied with oil.

[0011] The oil tank is preferably to be understood as an oil reservoir which is designed for the storage, preferably temporary storage, of the oil.

[0012] The advantage of the invention lies in the fact that the proposed valve unit allows a hydraulic actuator, in particular a disconnect unit, to be easily integrated into the oil circuit of a drive train and thus operated by the same pump. The three switching positions enable simple control of the valve unit, ensuring an oil supply to the oil circuit in both the open and closed states of the disconnect unit. This allows for a particularly simple and cost-effective integration of the disconnect unit. Furthermore, a valve unit is proposed that is characterized by high precision and reliability.

[0013] In a specific embodiment, the valve unit is designed as a 4 / 3-way valve. Specifically, a 4 / 3-way valve is defined as a directional control valve with four ports (pump, actuation, supply, and tank ports) and three switching positions (normal, actuation, and supply positions). The use of a 4 / 3-way valve results in a valve unit characterized by simple control and easy integration into the oil supply system.

[0014] In a further development, the valve unit has a return spring which exerts a restoring force on the valve spool towards its home position, whereby the return force moves the valve spool from the actuated position and the supply position into the home position. Specifically, the home position is to be understood as a first end position, the actuated position as an intermediate position, and the supply position as a second end position. In other words, the valve spool is deflected from the home position against the return force first into the actuated position and then into the supply position. The return spring can be designed as a compression spring, preferably a helical compression spring, which is supported on one side by the valve housing and on the other side by an end face of the valve spool.In the home position, energy consumption can be minimized because the valve spool is held in a fixed position by the return spring, eliminating the need for a continuous energy supply. This ensures both a continuous supply of oil to the circuit and the emptying of the hydraulic actuator, thus closing the clutch device, particularly the disconnect unit. This is necessary in most driving conditions, resulting in particularly efficient control of the valve unit.

[0015] In a further specific embodiment, the valve housing is provided with an additional pump connection for applying pump pressure to the valve spool, whereby the valve spool is moved from its neutral position to the actuated position and the supply position by the pump pressure. In simplified terms, the valve unit is designed as a fluid-controlled directional control valve, preferably a 4 / 3-way valve. The additional pump connection is understood here as a control port, through which the applied pump pressure is used to deflect the valve spool. In particular, the deflection of the valve spool is effected by the pump pressure, which acts on an end face of the valve spool against the restoring force. The movement of the valve spool is thus achieved by a change in the pump pressure, whereby the valve spool moves in the direction of the actuated or supply position.The valve spool moves to the supply position when the pump pressure increases and to the home position when the pump pressure decreases. A valve unit is therefore proposed in which the force required to move the valve spool is provided by the pump pressure.

[0016] In a further development, the valve unit is provided with at least one locking device designed to fix the valve spool in at least the actuated position and / or the supply position against the restoring force and / or the pump pressure. In particular, the locking device serves to fix the valve spool in the home position, the actuated position, and the supply position. Preferably, the locking device is electrically actuated, and the locking device is preferably energized to release the valve spool. The locking device prevents unintentional movement of the valve spool and ensures that the valve spool remains stable in the desired switching position even under pressure fluctuations.

[0017] In a further specification, the valve unit is provided with an additional locking device, wherein one locking device defines a stop in one direction of movement during the transfer of the valve spool, and the other locking device locks the valve spool in the opposite direction of movement after the transfer. In particular, the valve spool is designed such that, upon release of one of the two valve spools, it can be moved to the next switching position either by the pump pressure or the return spring. Preferably, the valve spool is always blocked in only one axial direction by the respective locking device and is freely or conditionally displaceable in the other axial direction. Preferably, the two locking devices are of identical construction. Preferably, the two locking devices are designed as locking magnets.The locking mechanism of the switching positions ensures reliable positioning of the valve spool, which is essential for the precise operation of actuators. Furthermore, the switching positions are clearly defined by the end stops and are therefore particularly easy to control.

[0018] In a further specific implementation, the locking device and / or the additional locking device comprise a locking element that is movable transversely to the direction of movement of the valve spool between a release position and a locked position, wherein the valve spool is supported and / or locked against the locking element in an axial direction with respect to the main axis in the locked position. When the locking device is actuated, the locking element is preferably moved from the locked position to the release position. Preferably, the locking devices designed as locking magnets have an electromagnet that moves the respective locking element to the release position or holds it in the release position upon activation or energization.Specifically, the locking element is spring-loaded in the direction of the locked position, so that it automatically returns to the locked position or is held in that position. The locking element can be designed as a pawl, pin, bolt, or similar component, which interacts with a corresponding locking contour on the valve spool. This proposes a mechanical locking mechanism for the valve spool that is particularly robust and simultaneously ensures secure fixation of the valve spool.

[0019] In a further specific implementation, the locking elements of the two locking devices are independently controllable. To move the valve spool to the next switching position, particularly the home position, actuation position, and / or supply position, one of the two locking elements is arranged in the release position, while the other locking element remains in the blocked position to form the end stop. To fix the valve spool in the respective switching position, the two locking elements are preferably arranged in the blocked position. Specifically, the valve spool is blocked in an axial direction by one locking element and in the opposite axial direction by the other locking element with respect to the main axis.To change the position, one of the locking elements is moved to the release position, while the other locking element remains in the blocked position to form the end stop for the next switching position. Depending on which locking element is moved to the release position, the valve spool can be moved to the next switching position either by the restoring force or the pump pressure. After the valve spool has been moved, the released locking element is moved back to the blocked position, and the valve spool is fixed. This proposes a particularly simple control method for the valve unit.

[0020] In a further specific embodiment, the valve slide is designed as a stepped piston with several axially separated cylinder chambers, wherein, depending on the piston position, at least two of the ports are connected to each other via a cylinder chamber. Specifically, this means that in the home position, the actuated position, and the supply position, at least two of the ports are connected to each other via a cylinder chamber. Preferably, the at least one locking device, more preferably the locking element, engages in one of the cylinder chambers to fix the valve slide. More preferably, both locking devices, more preferably the respective locking elements, engage in different cylinder chambers to fix the valve slide. Preferably, the cylinder chambers have a greater axial extent than the valve itself.The locking elements are designed so that the valve slide, in the locked position of one locking element and in the released position of the other locking element, is displaceable within the axial extent of the cylinder chamber relative to the locking element, in particular up to the end stop. This proposes a particularly simple design of the valve slide, in which the cylinder chambers also serve as a locking contour for the locking elements, thus enabling simple locking.

[0021] In a further specification, it is provided that the stepped piston has several cylinder sections for axially limiting the cylinder chambers, with at least one of the cylinder sections interacting with a sealing seat of the valve housing in the supply position to create a fluid-tight seal between the actuating port and the tank connection. The sealing seat serves to seal the actuating port, particularly after actuation of the hydraulic actuator, against the tank connection in order to prevent pressure loss in the hydraulic actuator. Specifically, at least one sealing device is provided on the stepped piston, preferably one of the cylinder sections, which preferably seals in the axial direction with respect to the main axis in the supply position, preferably creating a fluid-tight seal against the sealing seat.Due to the sealing seat, the stepped piston exhibits a particularly high pressure tightness towards the actuating connection, especially in the supply position.

[0022] Another aspect of the invention relates to an oil supply system for an electric drive train of a vehicle, with the valve unit as previously described.

[0023] The oil supply system comprises an oil circuit, preferably as previously described, which is designed and / or suitable for cooling and lubricating at least one drive and / or transmission component of the drivetrain. In particular, the oil circuit serves to cool electrical components, such as the electric motor, power electronics, etc., as well as mechanical components, such as bearings, gears, etc., to dissipate waste heat. Alternatively or optionally, the oil circuit also serves to lubricate mechanical components, such as gears, bearings, etc., to reduce friction. Optionally, the oil circuit can be thermally coupled to a further cooling circuit.

[0024] The oil supply system includes an oil tank, preferably as previously described, which is designed and / or suitable for the intermediate storage of oil. In particular, the oil for the oil supply is drawn from the oil tank to ensure a constant and targeted oil supply regardless of the driving situation. The pump unit can be connected to the oil tank via a pressure line to supply it with oil. Alternatively or additionally, the pump unit can be connected to the oil tank via a suction line to extract oil from it. Specifically, the oil tank can be equipped with a vent or pressure equalization system.

[0025] The oil supply system comprises at least one hydraulic actuator, preferably as previously described, which is designed and / or suitable for actuating the coupling device of the disconnect unit. In particular, the hydraulic actuator serves to convert hydraulic energy into mechanical motion. The hydraulic actuator can be designed as a hydraulic cylinder, preferably a single-acting hydraulic cylinder, which performs a linear movement based on the pump pressure. The coupling device can, in principle, be designed as a friction coupling, e.g., a multi-plate clutch. Preferably, however, the coupling device is designed as a positive-locking coupling, e.g., a sliding sleeve or claw. The coupling device is preferably closed in the unprinted state (normally closed) and open in the printed state.In other words, the disconnect unit opens when the pump pressure increases, or the electric machine is disconnected.

[0026] The oil supply system includes a pump unit, preferably as previously described, configured to pump oil from the oil tank either into the oil circuit or to the hydraulic actuator. In particular, the pump unit serves as the pressure source. The pump unit can be configured as an electric and / or mechanical pump unit. Specifically, an electric pump unit is understood to be one comprising at least one electrically operated pump. A mechanical pump unit is understood to be one comprising at least one mechanically operated pump. For example, the mechanically operated pump can be operatively connected to a rotating drive component and / or a rotating transmission component of the drive train. Specifically, the pump unit includes at least two pumps, forming a double pump with a common pump shaft.

[0027] Furthermore, the pump unit is designed to be fluidically connected to the pump connection, the hydraulic actuator to the actuation connection, the oil circuit to the supply connection, and the oil tank to the tank connection. Specifically, the pump unit includes a pressure pump, which is connected to the oil tank on the suction side and to the pump connection on the pressure side. Optionally, the pressure pump is connected to the additional pump connection on the pressure side to apply the pump pressure to the valve spool. The pump unit may also include at least one suction pump, which is connected to an oil source on the suction side and to the oil tank on the pressure side.

[0028] In a further development, it is provided that the oil supply system includes a dry sump, specifically as the oil source, which is designed and / or suitable for implementing dry sump lubrication. The pump unit is designed to pump the oil from the dry sump into the oil tank. In other words, the pump unit is designed to pump the oil from the dry sump into the oil tank and from the oil tank to the at least one oil supply point, with the oil then dripping or being collected back into the dry sump by gravity. For this purpose, the pump unit includes at least one pressure pump and a suction pump, with the suction pump being fluidically positioned between the dry sump and the oil tank. The oil tank is understood here as a separate oil container, preferably separate from the dry sump.Preferably, at least the rotating drive components and / or gearbox components are arranged outside, or at least largely outside, the dry sump. The advantage of dry sump lubrication is that the oil level in the oil sump or dry sump can be maintained at a constant, preferably lower, level by suction, thereby reducing churning losses and preventing thermal coupling between the rotor and stator.

[0029] In a more detailed design, the pump unit is connected to the oil tank via the suction line and to the pump connection and / or the additional pump connection via the pressure line. Specifically, the pressure pump is connected to the suction line on the suction side and to the pressure line on the pressure side. Preferably, the pressure line is directly connected to the pump connection and the additional pump connection. This ensures that the pump pressure at the valve spool corresponds to the pump pressure on the pressure side of the pressure pump. Thus, a particularly simple fluid-controlled valve unit is proposed.

[0030] In a further specification, the pump unit is connected to the dry sump via an additional suction line and to the oil tank via an additional pressure line. The tank connection is linked to the oil tank via a tank connection line and / or integrated into the additional pressure line. Specifically, the at least one suction pump is connected to the additional suction line on the suction side and to the additional pressure line on the pressure side. Preferably, the additional pressure line is directly connected to the oil tank, with the tank connection line potentially being a branch line opening into the additional pressure line. Alternatively, the tank connection line can also open directly into the oil tank and / or parallel to the additional pressure line. This allows the hydraulic actuator to be easily vented or emptied into the oil tank via the tank connection when in its home position.

[0031] A further aspect of the invention relates to a method for controlling the valve unit and / or the oil supply system, as previously described, in which the valve spool is moved to the actuating position to actuate the hydraulic actuator, whereby oil is conveyed from the pump port to the actuating port; the valve spool is moved to the supply position to supply the oil circuit, whereby oil is conveyed from the pump port to the supply port; and the valve spool is moved to the home position to supply the oil circuit and actuate the hydraulic actuator, whereby oil is conveyed from the pump port to the supply port and simultaneously oil is conveyed from the actuating port to the tank port. In other words, the hydraulic actuator is pressurized with the pump pressure in the actuating position and emptied or vented in the home position.Preferably, one of the locking devices is moved from the home position to the actuating position or from the actuating position to the supply position to the release position, while the other locking device remains in the locked position to form the end stop. Specifically, the oil supply system can include sensors designed to detect movement of the hydraulic actuator in the supply position due to a pressure drop, whereby the valve spool is briefly moved from the supply position to the actuating position upon reaching a threshold value in order to rebuild the pressure.

[0032] Further features, advantages, and effects of the invention will become apparent from the following description of preferred embodiments. These include: Fig. 1 a schematic representation of an oil supply system with a valve unit as an embodiment of the invention; Fig. 2 a perspective sectional view of the valve unit for the oil supply system from Fig. 1 in a basic position; Fig. 3 the valve unit, in the same view as in Fig. 2 shown, in an operating position; Fig. 4 the valve unit, in the same view as in Fig. 2 shown, in a supply position; Fig. 5 an alternative design of the valve unit, in the same view as in Fig. 2 shown, in the supply position; Fig. 6 a detailed view of the valve unit Fig. 5.

[0033] Fig. Figure 1 shows a schematic representation of an oil supply system 1 for an electric drive train of a vehicle as an embodiment of the invention. The oil supply system 1 comprises an electric machine 2, which includes a stator 3 and a rotor 4 arranged radially inside the stator 3. Furthermore, the electric machine 2 has a drive shaft 5, which is non-rotatably connected to the rotor 4 and is driven about a rotor axis 100.

[0034] The oil supply system 1 comprises an oil circuit 6, which serves to cool and / or lubricate at least one drive component, in particular the stator 3, the rotor 4, and / or the rotor shaft 5, by means of oil. The oil circuit 6 includes several oil supply points 7a, 7b, through which the oil is supplied specifically for cooling and / or lubricating the drive components. One or more oil supply points 7a can be assigned to the stator 2 and one or more oil supply points 7b to the rotor 11. For example, the rotor shaft 5 is designed as a hollow shaft, with the oil being supplied to the rotor 4 via the interior of the rotor shaft 5.

[0035] To implement dry sump lubrication, the oil supply system 1 has a dry sump 8 into which the oil can drip after being supplied via the oil supply points 7a, 7b. For example, at least the rotor 4 and the rotor shaft 5 are arranged outside the dry sump 8, thereby reducing churning losses.

[0036] The oil supply system 1 includes a disconnect unit 9 with at least one hydraulic actuator 10, shown only schematically, which can disconnect the mechanical connection of the electric machine 2 within a drive train. The hydraulic actuator 10 can, for example, be designed as a hydraulic cylinder that interacts with a coupling device (not shown). For example, the hydraulic actuator is actuated to interrupt a torque path of the electric machine 2 and / or to disconnect the rotor shaft 5. For example, the disconnect unit 9, in particular the coupling device, is normally closed by means of a spring.

[0037] The oil supply system 1 has a pump unit 11 which is designed to pump oil from the dry sump 8 into an oil tank 12 and from the oil tank 12 either to actuate the disconnect unit 9 to the hydraulic actuator 10 or to cool and / or lubricate the electric machine 2 to the oil supply points 7a, 7b.

[0038] The pump unit 11 comprises a first and a second suction pump 13a, 13b, which are designed to pump the oil from the dry sump 8 into the oil tank 12. Furthermore, the pump unit 11 comprises a pressure pump 14, which is designed to pump the oil from the oil tank 12 to the hydraulic actuator 10 or the oil supply points 7a, 7b. The two suction pumps 13a, 13b and the pressure pump 14 are each formed by a pump head, which are driven via a common pump shaft 15 by a common pump drive 16. For example, the pump drive 16 is designed as an electric motor.

[0039] Furthermore, the oil supply system 1 includes a cooling circuit 17, which serves to cool at least one electronic component, for example, power electronics 18 for controlling and supplying power to the electric machine 2. A coolant, e.g., water, can circulate in the cooling circuit 17. A heat exchanger 19 is arranged in the cooling circuit 17, via which the oil circuit 6 is thermally coupled to the cooling circuit 17 on the pressure side, or, from a flow engineering perspective, downstream of the pressure pump 14, in order to exchange heat energy between the oil circuit 6 and the cooling circuit 17. For this purpose, the heat exchanger 19 is designed as a liquid heat exchanger.

[0040] Furthermore, oil supply system 1 includes a valve unit 20, which is designed to control the oil flow rate. The valve unit 20 is located on the pressure side, or from a flow-related perspective, downstream of the pressure pump 14, and, depending on its switching position, connects the pressure pump 14 either to the oil circuit 6 or to the hydraulic actuator 10. For this purpose, the valve unit 20 can be switched between three different switching positions G, B, and V, which are described in more detail below.

[0041] Fig. Figure 2 shows a perspective sectional view of the valve unit 20 in a basic position G as an embodiment of the invention. The valve unit 20 has a valve housing 21, which has two pump connections 22a, 22b for connecting the pressure pump 14, an actuating connection 23 for connecting the hydraulic actuator 10, a supply connection 24 for connecting the oil circuit 6, and a tank connection 25 for connecting the oil tank 12. The valve housing 21 also has a valve chamber 26 in which a valve spool 27 is mounted so as to be displaceable axially with respect to a main axis 101. For example, the connections 22a, 22b, 23, 24, 25 are all arranged on one side of the valve housing 21 and / or are designed as through-holes opening radially into the valve chamber 26.

[0042] The valve slide 27 is designed as a stepped piston, which has several cylinder sections 28a to 28f spaced apart from each other in the axial direction with respect to the main axis 101. The cylinder sections 28a to 28f define several cylinder chambers 29a to 29g that are fluidically separated from each other in the axial direction with respect to the main axis 100, and through which a fluid connection between two ports 22a, 23, 24, 25 is either connected or interrupted depending on the switching position.

[0043] A first cylinder chamber 29a forms a pressure chamber, which is permanently connected to the pressure pump 14 via the further pump port 22b, so that the valve spool 27 is pressurized by the pump pressure generated by the pressure pump 14. In simplified terms, the pump port 22a forms a pressure port and the further pump port 22b a control port. Thus, the valve unit 20 is designed as a fluid- or pressure-controlled 4 / 3-way valve. The valve spool 27 can be moved from the neutral position G to the actuated position B or the supply position V by being pressurized by the pump pressure.

[0044] The pump pressure acts against a restoring force 102, which is applied to the valve spool 27 by a restoring spring 30. The restoring spring 30 is, for example, designed as a helical compression spring, which is arranged axially and / or coaxially with respect to the main axis 100 between the valve spool 27 and the valve housing 21 in the valve chamber 26, in particular a seventh pressure chamber 29g. The valve spool 27 is returned to its initial position G by the application of the restoring force 102 if the pressure force resulting from the pump pressure is less than the restoring force 102.

[0045] Furthermore, the valve unit 20 has two locking devices 31a, 31b, which are designed to fix the valve spool 27 at least in the respective switching positions G, B, V against the restoring force 102 and against the pump pressure. For this purpose, the two locking devices 31a, 31b each have a locking element 32a, 32b, which are each independently movable transversely to the direction of movement of the valve spool 27 between a release position F and a locking position S. The two locking devices 31a, 32b are each designed as a locking magnet, each of which has an electromagnet 33a, 33b for moving the respective locking element 32a, 32b into the release position F.The two locking elements 32a, 32b are spring-loaded in the direction of the locking position S, whereby when the electromagnet 33a, 33b is energized, the corresponding locking element 32a, 32b is moved into the release position S.

[0046] In the basic position G, the two locking elements 32a, 32b are arranged in the locking position S, whereby the valve slide 27 is axially fixed by the two locking elements 32a, 32b. For this purpose, one locking element 32a engages in a fourth cylinder chamber 29d and the other locking element 32b in a second cylinder chamber 29b, wherein the valve slide 27 rests against the locking element 32a in an axial direction with a third cylinder section 28c and against the other locking element 32b in an axial opposite direction with a second cylinder section 28b.

[0047] In an installation situation such as in Fig. As shown schematically in Figure 1, the valve unit 20 with the two pump connections 22a, 22b is connected to the pressure side of the pressure pump 14 via a pressure line 35. The pressure pump 14 is connected to the oil tank 12 via a suction line 34 on the suction side. Furthermore, the valve unit 20 with the tank connection 25 is connected to the pressure side of the two suction pumps 13a, 13b and the oil tank 12 via a tank return line 36. The suction pumps 13a, 13b are connected to the dry sump 8 via another suction line 37 on the suction side and to the oil tank 12 via another pressure line 38 on the pressure side, whereby the tank return line 36 can, for example, be integrated into the other pressure line 38. In addition, the hydraulic actuator 10 is connected to the actuation port 23 via a connecting line 39 and the oil circuit 6 is connected to the supply port 24 via another connecting line 40.

[0048] In the basic position G, the pump connection 22a is fluidically connected to the supply connection 24, specifically via a fifth cylinder chamber 29e, and the actuation connection 23 is fluidically connected to the tank connection 25, specifically via a sixth cylinder chamber 29f. During pump operation, oil is thus delivered to the oil circuit 6 via the pressure pump 14, while the hydraulic actuator 10 is emptied or vented into the oil tank 12 and is therefore depressurized. Thus, in the basic position G, the oil circuit 6 is supplied with oil, while the disconnect unit 10 is closed.

[0049] Fig. Figure 3 shows the valve unit 20 in the actuating position B, whereby the first locking device 31a is actuated to move the valve spool 27 into the actuating position B, so that the associated locking element 32a moves into the release position F and the valve spool 27 is moved from the home position G to the actuating position B due to the acting pump pressure. The locking element 32b of the second locking device 31b remains in the locking position S and simultaneously forms an end stop for the valve spool 27 in the actuating position B. Upon reaching the actuating position B, the first locking element 32a is moved back into the locking position S, so that it engages in the previously adjacent cylinder chamber 29c and the valve spool 27 is fixed axially opposite to the direction of movement.

[0050] In operating position B, the pump connection 22a is fluidically connected to the operating port 23, specifically via the fifth cylinder chamber 29e, while the supply port 24 and the tank connection 24 are fluidically separated from each other and from the pump connection 22a and the operating port 23. During pump operation, oil is thus delivered from the pressure pump 14 to the hydraulic actuator 10, thereby pressurizing the hydraulic actuator 10 with the pump pressure. In operating position B, this actuates the hydraulic actuator 10, opening the disconnect unit 10 while interrupting the oil supply to the oil circuit 6.

[0051] Fig. Figure 4 shows the valve unit 20 in the supply position V. To move the valve spool 27 into the supply position V, the second locking device 31b is actuated, so that the associated locking element 32b moves into the release position F and the valve spool 27 is moved from the actuating position B to the supply position V due to the acting pump pressure. The locking element 32a of the first locking device 31a remains in the blocked position S and simultaneously forms an end stop for the valve spool 27 in the supply position V. Upon reaching the supply position V, the second locking element 32b is moved back into the blocked position S, so that it engages in the previously adjacent cylinder chamber 29a and the valve spool 27 is fixed axially opposite to the direction of movement.

[0052] In supply position V, the pump connection 22a is fluidically connected to the supply connection 24, specifically via the fourth cylinder chamber 29d, while the actuating connection 23 and the tank connection 24 are fluidically separated from each other and from the pump connection 22a and the supply connection 24. During pump operation, oil is thus delivered to the oil circuit 6 via the pressure pump 14, while the hydraulic actuator 10 is pressurized by the pump pressure. Therefore, in supply position V, the oil circuit 6 is supplied with oil, while the disconnect unit 10 is open.

[0053] The valve slide 27 is reset from the supply position V or the actuation position B to the home position G by a reverse control of the locking devices 31a, 31b, whereby the pump pressure must be reduced at the same time so that a reset by the return spring 30 is ensured.

[0054] Fig. Figure 5 shows an alternative embodiment of the valve unit 20 in the supply position V, wherein the actuating port 23 is fluid-tightly sealed against the tank port 25 by a sealing device 41. This ensures that the hydraulic actuator 10 has a high pressure tightness in the actuated or pressurized state and thus prevents the disconnect unit 9 from closing automatically due to a pressure loss.

[0055] Optionally, sensors can be provided that detect movement of the hydraulic actuator and / or the coupling device, for example the sliding sleeve, if the oil pressure in the hydraulic actuator 10 drops accordingly. The oil pressure can then be rebuilt by means of appropriate wiring, whereby the valve spool 27 is briefly moved from the supply position V to the actuation position B.

[0056] Fig.Figure 6 shows a detailed view of the valve unit 20 with the sealing device 41 in the supply position V. The valve housing 21 has a sealing seat 42 against which the sealing device 41, in the supply position V, seals in the axial direction with respect to the main axis 101. The sealing seat 42 is formed by a reduction in the diameter of the valve chamber 26, with the sealing device 41 being fixed to one of the cylinder sections 28e, which, in the supply position V, separates the actuating port 23 from the tank connection 25. For example, the sealing device 41 is designed as an O-ring, which is inserted in an annular groove 42 provided on the outer circumference of the cylinder section 28e. This ensures a particularly reliable seal of the actuating port 23 in the supply position V. Reference sign 1 Oil supply system 2 electric machine 3 Stator 4 Rotor 5 Rotor shaft 6 Oil circuit 7a, b Oil supply points 8 Dry swamp 9 Disconnect Unit 10 hydraulic actuators 11 Pump unit 12 Oil tank 13a, b Suction pumps 14 Pressure pump 15 Pump shaft 16 Pump drive 17 Cooling circuit 18 Power Electronics 19 heat exchangers 20 valve unit 21 Valve housings 22a, b Pump connections 23 Actuating connection 24 supply connection 25 Tank connection 26 Valve chamber 27 valve slides 28a-f Cylinder sections 29a-g Cylinder spaces 30 Return spring 31a, b Locking devices 32a, b Locking elements 33a, b Electromagnets 34 Suction line 35 Pressure line 36 Tank connection line 37 additional suction lines 38 more pressure lines 39 Connection cable 40 additional connection lines 41 Sealing device 42 Sealing seat 43 Ring groove 100 Rotor axis 101 Main axis 102 Restoring force B Actuation position G Basic position F Release position S Locking position V Supply position QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2021 104 241 B3

[0003]

Claims

[1] Valve unit (20) for an oil supply system (1) of an electric powertrain of a vehicle, - with a valve housing (21) which has at least one pump connection (22a) for connecting a pump unit (11), an actuation connection (23) for connecting a hydraulic actuator (9) and a supply connection (24) for connecting an oil circuit (6), - with a valve slide (27) which is movable in the axial direction with respect to a main axis (101) within the valve housing (21) between a basic position (G), an actuating position (B) and a supply position (V), wherein in the actuating position (B) the pump port (22a) is connected to the actuating port (23) and in the supply position (V) the pump port (22a) is connected to the supply port (24), characterized by, that the valve housing (21) has a tank connection (25) for connection to an oil tank (12), wherein in the basic position (G) the pump connection (22a) is connected to the supply connection (24) and at the same time the actuating connection (23) is connected to the tank connection (25). [2] Valve unit (20) according to claim 1, characterized by , that the valve unit (20) is designed as a 4 / 3-way valve. [3] Valve unit (20) according to claim 1 or 2, characterized by a return spring (30) which applies a return force (102) to the valve slide (27) in the direction of the home position (G), whereby a transfer of the valve slide (27) from the actuating position (B) and the supply position (V) to the home position (G) is possible by the return force (102). [4] Valve unit (20) according to one of the preceding claims, characterized by, that the valve housing (21) has a further pump connection (22b) for applying a pump pressure from the pump unit (11) to the valve spool (27), wherein the valve spool (27) can be moved from the home position (G) to the actuating position (B) and the supply position (V) by the pump pressure. [5] Valve unit (20) according to one of the preceding claims, characterized by at least one locking device (31a) which is designed to fix the valve slide (27) at least in the actuating position (B) and / or in the supply position (V) against the restoring force (102) and / or against the pump pressure. [6] Valve unit (20) according to claim 5, characterized bya further locking device (31b), wherein one locking device (31a, 31b) defines a stop in one direction of movement when the valve slide (27) is moved, and the other locking device (31a, 31b) locks the valve slide (27) after the move in the opposite direction of movement. [7] Valve unit (20) according to claim 5 or 6, characterized by , that the locking device (31a) and / or the further locking device (31b) have a locking element (32a, 32b) which is movable transversely to the direction of movement of the valve slide (27) between a release position (F) and a locking position (S), wherein the valve slide (27) in the locking position (S) is supported and / or locked in an axial direction with respect to the main axis (100) on the locking element (32a, 32b). [8] Valve unit (20) according to claim 7, characterized by, that the locking elements (32a, 32b) of the two locking devices (31a, 31b) are independently controllable, wherein, in order to move the valve slide (27) at least into the actuating position (B) and / or into the supply position (V), one of the two locking elements (32a, 32b) is arranged in the release position (F) and the other locking element (32a, 32b) is arranged in the locking position (S) to form the end stop. [9] Valve unit (20) according to any one of the preceding claims, characterized by , that the valve slide (27) is designed as a stepped piston which defines several axially separated cylinder chambers (29a-g), wherein, depending on the switching position (G, B, V), at least two of the ports (22a, 23, 24, 25) are connected to each other via one of the cylinder chambers (29a-g). [10] Valve unit (20) according to claim 9, characterized by, that the stepped piston has several cylinder sections (28a-f) for axially limiting the cylinder spaces (29a-g), wherein at least one of the cylinder sections (28a-f) in the supply position (V) interacts with a sealing seat (42) of the valve housing (21) to fluid-tightly seal the actuating port (23) against the tank port (25). [11] Oil supply system (1) for an electric powertrain of a vehicle, - with an oil circuit (6) for cooling and / or lubricating at least one drive component of the drive train by means of oil, - with an oil tank (12) for intermediate storage of the oil, - with at least one hydraulic actuator (10) for actuating a coupling device of a disconnect unit (9), - with a pump unit (11) which is designed to pump the oil from the oil tank (12) either into the oil circuit (6) or to the hydraulic actuator (10), characterized bya valve unit (20) according to one of the preceding claims, wherein the pump unit (11) is fluidically connected to the pump connection (22a), the hydraulic actuator (10) to the actuation connection (23), the oil circuit (6) to the supply connection (24) and the oil tank (12) to the tank connection (25). [12] Oil supply system (1) according to claim 11, characterized by a dry sump (8) wherein the pump unit (11) is designed to pump the oil from the dry sump (8) into the oil tank (12) for the implementation of a dry sump lubrication. [13] Oil supply system (1) according to claim 11 or 12, characterized by , that the pump unit (11) is connected to the oil tank (12) via a suction line (34) and is connected to the pump connection (22a) and / or to the further pump connection (22b) via a pressure line (35). [14] Oil supply system (1) according to 12 and 13, characterized by, that the pump unit (11) is connected to the dry sump (8) via a further suction line (37) and to the oil tank (12) via a further pressure line (38), wherein the tank connection (25) is connected to the oil tank (12) via a tank connection line (36) and / or is integrated into the further pressure line (38). [15] Method for controlling the valve unit (20) according to any one of claims 1 to 10 and / or the oil supply system (1) according to any one of claims 11 to 14, wherein: - the valve slide (27) is moved to the actuating position (B) to actuate the hydraulic actuator (10), whereby oil is conveyed from the pump port (22a) to the actuating port (23); - the valve slide (27) for supplying the oil circuit (6) is moved into the supply position (V), whereby oil is pumped from the pump connection (22a) to the supply connection (24); - the valve slide (27) is moved to the home position (G) to supply the oil circuit (6) and to actuate the hydraulic actuator (10), whereby oil is pumped from the pump connection (22a) to the supply connection (24) and at the same time oil is pumped from the actuating connection (23) to the tank connection (25).

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