Hydraulic arrangement for a working machine

Abstract

A hydraulic system is provided for a working machine. The hydraulic system comprises a system pressure control device (11), a cooler (12), and an electro-hydraulic cooler bypass valve (13). The system pressure control device (11) is designed to discharge oil at a high-pressure pressure to a high-pressure path (22). The cooler (12) is connected to the system pressure control device (11) for cooling the high-pressure oil. The electro-hydraulic cooler bypass valve (13) is connected to the high-pressure path (22) with at least a portion of the high-pressure oil to bypass the cooler (12).

Description

Technical field The present invention relates to a hydraulic arrangement for a working machine, to a gearbox with a hydraulic arrangement, to a method for controlling the hydraulic arrangement and to a working machine with a gearbox. State of the art Hydraulic arrangements for a working machine are known. A hydraulic arrangement serves, among other things, to operate the transmission of a working machine. With the increasing complexity of transmissions for working machines and the growing number of components and parts installed in working machines and their transmissions, the effort required to manufacture the working machines and their transmissions is high. US 2014 / 0193230A1 discloses a hydraulic circuit for a work vehicle with a radiator and a radiator bypass valve. One inlet of the radiator bypass valve is fluidically connected to a pressure side of a pump. Both outlets of the radiator bypass valve are fluidically connected to a reservoir. Further hydraulic arrangements are shown in DE 19651988A1 and DE 102020213773A1. Description of the invention It is an object of the present invention to provide an improved hydraulic arrangement with which a gearbox for a working machine can be operated efficiently and gently. The problem is solved by a hydraulic arrangement having the features of claim 1. Advantageous further developments are the subject of the dependent claims. In the first aspect, a hydraulic arrangement for a working machine is provided. The hydraulic arrangement includes a system pressure control device, a cooler, and an electro-hydraulic cooler bypass valve. The system pressure control device is designed to deliver oil at a pressure, for example, high pressure, as high-pressure oil to a high-pressure path. The oil can be hydraulic oil. The cooler is connected to the system pressure control device, for example, fluidically, to cool the high-pressure oil. The cooler bypass valve is connected to the high-pressure path, for example, fluidically, to bypass at least a portion of the high-pressure oil from the cooler. An inlet channel and an outlet channel of the cooler bypass valve are fluidically connected to the high-pressure path to bypass at least a portion of the high-pressure oil from the cooler. The vehicle can be configured as a work machine, such as a wheel loader, tractor, dump truck, or similar. The work machine can have a working device. The working device can be designed to perform a work task, such as lifting a load, transporting a load, powering a work tool, or the like. The work tool can be an agricultural implement, such as a plow, tedder, mulcher, or similar. The working device can be hydraulically operated, for example, via a hydraulic system. The hydraulic system can include a pump to supply the hydraulic system at a specific pressure. If two elements are fluidically connected, a fluid, such as oil, can be conveyed from one element to the other. The fluid connection can be leak-free, so that the fluid is essentially conveyed completely from one element to the other. The fluid connection can be a channel, a pipe, a hose, or the like. The fluid connection can be a direct fluid connection without any additional elements between the fluidically connected elements. Alternatively, the fluid connection can be an indirect fluid connection via additional elements between the fluidically connected elements. The system pressure adjustment device can be designed to receive oil, for example, low-pressure oil. For this purpose, the system pressure adjustment device can have a low-pressure interface. The low-pressure oil can have a low pressure that may be lower than the high pressure. The system pressure adjustment device can be designed to receive low-pressure oil, for example, from a low-pressure path. The system pressure adjustment device can be designed to pressurize the oil, for example, high pressure, pilot pressure, or the like. The system pressure adjustment device can have multiple valves and / or pumps for pressurizing the oil. Valve bodies for several or all of the valves can be formed from a common valve body unit. The system pressure adjustment device can have a pilot pressure pump or gear pump for pressurizing the oil as pilot pressure oil. The system pressure control device may include a control pressure valve designed to receive the control pressure oil and limit its flow to the control pressure. The control pressure valve may be configured as a pressure relief valve. An outlet of the control pressure valve may be configured to discharge the high-pressure oil to the high-pressure path. An inlet of the control pressure valve may be configured to discharge the control pressure oil to a control pressure path, for example, via a control pressure interface. The control pressure oil may be used to operate a hydrostatic transmission of the driven machine. The control pressure oil may be used to actuate switching elements of a transmission of the driven machine. The gear pump can be fluidically connected to the low-pressure path. The gear pump can be fluidically connected to the low-pressure interface, for example, via the low-pressure path. The gear pump can be designed, for example, for a driven machine. The gear pump can be designed for a flow rate in the range of 20–150 l / min, for example, 50–90 l / min. The gear pump can be fluidically connected, for example, directly, to the low-pressure interface, for example, to receive low-pressure oil. The low-pressure oil received by the low-pressure interface can be filtered. Before the low-pressure oil is received by the low-pressure interface, it can have passed through a filter device, for example, an oil filter. The filter device can be designed to clean the low-pressure oil, for example, to remove contaminants. The pressure of the pilot pressure oil can be higher than the pressure of the high-pressure oil. The low pressure can have a value in the range of 1 to 5 bar, for example, 1.5 to 3 bar. The high pressure can have a value in the range of 3 to 12 bar, for example, 5 to 10 bar. The pilot pressure can have a value in the range of 10 to 35 bar, for example, 12 to 30 bar. The oil for the control pressure oil, the low-pressure oil, the high-pressure oil, and the working pressure oil can all be the same oil, but with different pressure levels. The hydraulic system can include, for example, the low-pressure oil, the control pressure oil, the high-pressure oil, and the working pressure oil. Each oil can be a hydraulic oil. Each oil can have lubricating properties. Each oil can have cooling properties. The system pressure control device can be configured to discharge pressurized oil via an interface. The system pressure control device can have a high-pressure output interface, which can be connected to the high-pressure path for discharging high-pressure oil, for example, via a fluid connection. The system pressure control device can have a high-pressure input interface, which can be connected to the high-pressure path for receiving high-pressure oil, for example, via a fluid connection. The high-pressure output interface can be configured to direct high-pressure oil to a cooler. The high-pressure input interface can be configured to receive high-pressure oil from the cooler. The cooling system can be designed as a heat exchanger, for example as an active or passive radiator, or a heat transfer unit. The cooling system can be configured to regulate the oil temperature. This temperature regulation can include cooling, for example during normal operation of the machine. It can also include heating, for example during machine start-up. The cooler can be connected to the high-pressure outlet interface for receiving high-pressure oil, for example, via a fluid connection. The cooler can be configured to cool the high-pressure oil. The cooler can be connected to the high-pressure inlet interface for discharging cooled high-pressure oil, for example, via a fluid connection. The hydraulic system can direct at least a portion of the high-pressure oil to the cooler via the high-pressure outlet interface. The proportion of high-pressure oil directed to the cooler can be adjustable via the cooler bypass valve. The radiator bypass valve allows at least a portion of the high-pressure oil to bypass the radiator assembly and / or the high-pressure outlet and inlet interfaces, thus at least partially bypassing these elements fluidically. The radiator bypass valve can be electrically actuated, for example, via an electromagnetic valve unit. The radiator bypass valve can also be designed to control the oil flow rate through it, for example, via a hydraulic valve unit. The electromagnetic valve unit can be coupled to the hydraulic valve unit to control the oil flow rate. The electromagnetic valve unit can be controlled by an electrical control current or voltage. The cooler bypass valve can incorporate both a hydraulic valve unit and an electromagnetic valve unit. This allows the cooling capacity of the high-pressure oil routed through the cooler to be adjusted as needed. This enables the high-pressure oil to be quickly brought up to the desired operating temperature and maintained at that temperature. This facilitates rapid and efficient temperature control, resulting in efficient gearbox operation with minimal friction losses and thus a long gearbox service life. In one embodiment of the hydraulic arrangement, the arrangement may include a sensing device and a control device. The sensing device is configured to detect the actual oil temperature and an actual operating parameter of the driven machine. The control device is connected to the cooler bypass valve, for example via a fluid connection, to adjust the actual oil temperature to an adjustable target temperature based on the actual temperature and the actual operating parameter of the driven machine. The sensing device can include one or more sensors, such as a temperature sensor, a speed sensor, a pressure sensor, or the like. The sensing device can be connected directly or indirectly to the control unit to transmit the actual oil temperature and the actual operating parameter, for example, via an electrical connection. The sensing device can be connected to the control unit via a vehicle control unit, for example. The actual oil temperature can refer to the temperature of the oil, for example, in a reservoir, the low-pressure oil, the high-pressure oil, and / or the control pressure oil. The actual operating parameter can include at least one of the following: speed, torque, load condition, power gradient, characteristic data (e.g., engine characteristics), drive unit and travel speed of the machine, and oil pressure (e.g., high pressure or control pressure).The control unit can be configured to execute a procedure described later. The control unit can have an input interface and an output interface. The input interface can be configured to receive signals, for example, system information about at least one of the current operating parameters, the current temperature, and the like. The input interface can be configured to receive system information via the acquisition interface. The output interface can be configured to output signals for controlling the cooler bypass valve. The output interface can be configured to control the electromagnetic valve unit, for example, to open and close it.The control device may include a storage medium, for example at least one of a solid-state memory, a volatile memory or a permanent memory, for storing data, system information and a program for executing the procedure. In one embodiment of the hydraulic arrangement, the hydraulic arrangement can include a reservoir, a low-pressure pump, and a low-pressure path. The reservoir can be configured to receive the oil. The reservoir can be configured to store the oil. The reservoir can be configured to provide an oil sump. The sensing device can be configured to detect the actual temperature of the oil in the reservoir. The low-pressure pump can be configured to pressurize the oil from the reservoir at low pressure (low-pressure oil) and to discharge the low-pressure oil into the low-pressure path. The system pressure control device can be connected to the low-pressure path for receiving the low-pressure oil. The system pressure control device can be configured to pressurize the low-pressure oil at high pressure (high-pressure oil). The low-pressure pump can be connected to the reservoir for oil intake, for example, via a fluid connection. The hydraulic assembly can include at least one filter device, for example, an oil filter. The low-pressure pump can be connected to the reservoir via the filter device, for example, via a fluid connection. The low-pressure pump can be connected to the low-pressure path via the filter device for discharge of the low-pressure oil, for example, via a fluid connection. The hydraulic assembly can include a filter bypass valve. The filter bypass valve can be configured to bypass the filter device with at least a portion of the low-pressure oil from the low-pressure pump to the low-pressure path. The system pressure adjustment device may have a low-pressure interface. The system pressure adjustment device may be designed to be connected to the low-pressure path via this interface, for example, via a fluid connection. The low-pressure interface may be designed to receive the low-pressure oil. In one embodiment of the hydraulic arrangement, the cooler bypass valve can be designed as a proportional valve. The proportional valve can be configured to control the flow rate of oil, for example through the cooler bypass valve, depending on the control current or voltage. This allows the proportional valve to be configured for a variably adjustable flow rate. In one embodiment, the radiator bypass valve can be configured as an indirect valve. The radiator bypass valve can comprise a hydraulic valve unit and an electromagnetic valve unit. The hydraulic valve unit can have an open valve state in which it is configured to bypass the radiator assembly with at least a portion of the high-pressure oil from the high-pressure path. The electromagnetic valve unit can be configured to discharge oil at an actuating pressure to actuate the hydraulic valve unit. A valve, for example a hydraulic valve unit and / or an electromagnetic valve unit, can have a valve body. The valve body can form an inlet channel for introducing oil into the valve. The valve body can form an outlet channel for expelling oil from the valve. The valve body can have a movement surface, for example a recess, extending in an axial direction of the valve. The recess can have a cylindrical shape. The valve body can form an actuation chamber, which can be configured for actuating the valve, for example hydraulically. The valve can have a valve element, for example a valve piston. The valve element can be movably arranged along the movement surface. The valve element can have an outer circumference that is adapted to the movement surface.Then the valve housing body can be designed to receive the valve element. The valve element can have two valve positions. Depending on the design of the valve body and the number of inlet and outlet channels, a valve element can also have multiple valve positions, and the valve can have multiple valve states. One valve position can be a closed position, in which the valve is closed. In the closed position, the valve element can reduce or prevent the flow of oil from the inlet to the outlet channel. The valve can then be in a closed valve state. Another valve position can be an open position, in which the valve is open. In the open position, the valve element can allow the flow of oil from the inlet to the outlet channel. The valve element can be moved in the closing direction, for example, in the axial direction of the valve, so that it can be brought into the closed position.The valve element can be moved, for example in the opposite direction to the closing direction, so that the valve can be opened. The valve can have a preload element, for example, a spring element, a coil spring, a compression spring, a pneumatic spring, or the like. The preload element can apply a preload force to the valve element. The preload element can preload the valve element towards a valve position, for example, the closed position. The hydraulic valve unit can be hydraulically actuated. The valve element of the hydraulic valve unit can be actuated by an actuating pressure, for example, the high pressure or the control pressure, applied to a pressure surface, such as in an actuation chamber of the hydraulic valve unit. A pressure force can be applied to the valve element at the pressure surface via the oil pressure. The preload force can be opposite to the pressure force. If the pressure force exceeds the preload force, the valve element can be moved to the other valve position, for example, the open position. An inlet channel and an outlet channel of the hydraulic valve unit can be fluidically connected to the high-pressure path with at least a portion of the high-pressure oil to bypass the cooling device, for example, when the hydraulic valve unit is in the open valve state.The open and closed valve states of the hydraulic valve unit can be related to the open and closed valve states of the cooler bypass valve. A valve element of the electromagnetic valve unit can be actuated by an actuating force, which can be provided, for example, by an electrical coil. The actuating force can be adjustable via the control current or control voltage. The actuating force can be opposite to the preload force. If the actuating force exceeds the preload force, the valve element can be moved to the other valve position, for example, the open position. An output channel of the electromagnetic valve unit can be fluidically connected to the actuating chamber of the hydraulic valve unit. In the open valve state of the electromagnetic valve unit, the actuating chamber of the hydraulic valve unit can be fluidically connected to the input channel of the electromagnetic valve unit.This allows the electromagnetic valve unit to provide the actuation pressure for the hydraulic valve unit at its input channel. The input channel of the electromagnetic valve unit can be fluidically connected to either the high-pressure or the pilot pressure path. This enables the electromagnetic valve unit to supply either high-pressure or pilot pressure oil as actuation fluid for the hydraulic valve unit. The electromagnetic valve unit can be connected to the control device to control the valve state of the radiator bypass valve, for example, by electrical connection. The radiator bypass valve can be designed as a normally closed valve. In one embodiment of the hydraulic arrangement, the electromagnetic valve unit can be connected to the high-pressure path for receiving high-pressure oil. The electromagnetic valve unit can be configured to discharge the high-pressure oil to the hydraulic valve unit as actuating oil. The valve body of the cooler bypass valve can be formed by a separate, for example, external, valve body unit. In one embodiment of the hydraulic arrangement, the system pressure adjustment device can be configured to supply oil at a control pressure to the control pressure path. The control pressure can be higher than the high pressure. The electromagnetic valve unit can be connected to the control pressure path to receive the control pressure oil, for example, via a fluid connection. The electromagnetic valve unit can be configured to supply the control pressure oil to the hydraulic valve unit as actuating oil. The valve bodies of the cooler bypass valve can be integrated into the common valve body unit. In a second aspect, a gearbox of a hydraulic arrangement according to the first aspect is provided. Features, effects, and advantages of the first aspect also represent features, effects, and advantages for the second aspect. Conversely, features, effects, and advantages of the second aspect represent features, effects, and advantages for the first aspect. The gearbox has a hydraulic consumer, an input element, and an output element. The hydraulic consumer is connected to the high-pressure path for receiving high-pressure oil, for example, via a fluid connection. The input element is designed to receive a driving force. The output element is designed to output a driving force. The gearbox provides a transmission ratio from the input element to the output element. The transmission can provide an adjustable gear ratio, for example, switchable and / or variable, between the input and output elements. The transmission can provide several such gear ratios. The transmission can have at least one switching element, for example, for switching between at least two gear ratios. The switching element can be hydraulically actuated, for example, via pilot pressure oil. The transmission can have several switching elements and / or a switching control device for distributing the pilot pressure oil to one or more switching elements. The switching element can constitute a hydraulic consumer. The transmission can have other hydraulic consumers, for example, lubrication points, cooling points, a hydrostatic drive, a variator, a hydrostatic transmission component, or the like, or a combination thereof. The hydraulic consumer can be designed to remove used oil, for example, after a cooling process, a switching operation, or a lubrication process. The hydraulic consumer can be fluidically connected to the reservoir, for example, directly, to discharge used oil. The hydraulic consumer can have a discharge interface. The discharge interface can be fluidically connected to the reservoir, for example, directly. In a third aspect, a working machine with a transmission according to the second aspect is provided. Features, effects, and advantages of any of the preceding aspects represent features, effects, and advantages for the third aspect. Conversely, features, effects, and advantages of the third aspect represent features, effects, and advantages for the preceding aspects. The working machine has a drive unit and at least one traction element. The drive unit is mechanically connected to the input element of the transmission for the purpose of applying a driving force. The traction element is mechanically operatively connected to the output element of the transmission for the purpose of moving the working machine. A traction element can be designed as a track drive or a drive wheel. The working machine can have multiple traction elements. If two elements are mechanically connected, they are coupled to each other directly or indirectly in such a way that a movement of one element causes a reaction of the other. For example, a mechanical connection can be provided by a positive-locking or friction-locking connection. The mechanical connection can correspond to the meshing of corresponding gear teeth on the two elements. Further elements, such as one or more spur gear stages, can be provided between the elements. A permanently rotationally fixed connection between two elements, on the other hand, is understood to be a connection in which the two elements are rigidly coupled to each other in all intended states of the transmission. The elements can be individual components rigidly connected to each other or even as a single piece.However, a switching element, such as a clutch or brake, can be used to selectively establish or break a rotationally fixed connection between two elements. The drive unit can include a drive motor, for example, an electric motor and / or an internal combustion engine. The drive unit can have an output shaft. The drive unit can be designed to output a driving force at the output shaft. The output shaft of the drive unit can be mechanically connected to the input element of the transmission. The output element of the transmission can be mechanically connected to one or more traction elements via at least one drive shaft and a differential. The machine may have a vehicle control unit. The vehicle control unit may be configured to output control signals for controlling the drive unit and / or the transmission. The vehicle control unit may be connected to the sensing device to receive the current temperature and operating parameters, for example, by electrical connection. The vehicle control unit may also be connected to the control device to transmit the current temperature and operating parameters, for example, by electrical connection. A fourth aspect describes a method for controlling a hydraulic arrangement according to the first aspect. Features, effects, and benefits of any of the preceding aspects represent features, effects, and benefits for the fourth aspect. Conversely, features, effects, and benefits of the fourth aspect represent features, effects, and benefits for the preceding aspects. The method includes sensing the actual temperature and the actual operating parameter using the sensing device. The method further includes adjusting the actual temperature to an adjustable setpoint temperature by actuating the cooler bypass valve, depending on the actual temperature and the actual operating parameter. The actual temperature can include the actual temperature of oil in the reservoir. The adjustment of the actual temperature can be based on an actual temperature gradient.The actual operating parameter can include at least one of the following: rotational speed, torque, load condition, power gradient, characteristic data (e.g., engine characteristics), drive unit, the travel speed of the machine, and the oil pressure (e.g., high pressure or control pressure). Adjusting the actual temperature can involve increasing it, for example, raising it early, to the target temperature. Adjusting the actual temperature can also involve decreasing it, for example, reducing it early, to the target temperature. Adjusting the actual temperature can involve opening and / or closing the cooler bypass valve. Adjusting the actual temperature can involve setting or adjusting the cooling capacity, for example, the amount of high-pressure oil passing through the cooler. The procedure can include determining the operating state of the machine based on the current operating parameter. An operating state can include start-up, acceleration, constant speed operation, maximum power operation, braking, or similar conditions. The procedure can include adjusting the actual temperature to the target temperature early on, depending on the current operating state. The procedure can also include adjusting the actual temperature by actuating the cooler bypass valve, again depending on the current operating state. For example, cooling capacity can be increased if the actual temperature gradient is high, meaning the oil heats up quickly. Conversely, cooling capacity can be reduced even if the actual temperature gradient is high, such as when the machine is starting up.This allows the gearbox and drive unit to quickly heat up to a desired operating temperature, or setpoint temperature, during start-up. For example, cooling capacity can be increased even with a low actual temperature gradient when the machine is braking or operating at maximum power. Different setpoint temperatures can be specified for different operating conditions. The setpoint temperature can be configured by the user via the control unit. Brief description of the characters Fig. 1 is a schematic representation of one embodiment of a hydraulic arrangement for a machine. Fig. 2 is a schematic representation of another embodiment of the hydraulic arrangement. Fig. 3 is a schematic representation of another embodiment of the hydraulic arrangement. Fig. 4 is a top view of a schematic representation of an embodiment of a machine with the hydraulic arrangement. Fig. 5 is a flowchart of an embodiment of a method for controlling the hydraulic arrangement. Detailed description of embodiments Fig. 1 is a schematic representation of an embodiment of a hydraulic arrangement for a machine. The hydraulic arrangement includes a system pressure control device 11 with a high-pressure outlet interface 42 for supplying high-pressure oil to a high-pressure path 22. The high-pressure oil is supplied by oil, in this case hydraulic oil, at high pressure. The system pressure control device 11 has a high-pressure inlet interface 43 for receiving high-pressure oil from the high-pressure path 22. The hydraulic arrangement includes a cooler 12, which is fluidically connected to the system pressure control device 11 via the high-pressure inlet interface 43 and the high-pressure outlet interface 42 for cooling the high-pressure oil. The hydraulic arrangement includes an electro-hydraulic cooler bypass valve 13, which is connected to the high-pressure path 22 with at least a portion of the high-pressure oil to bypass the cooler 12.The cooler bypass valve 13 is electrically actuated. This allows the cooling capacity of the high-pressure oil routed through the cooler unit 12 to be adjusted as needed. This enables fast and efficient temperature control of the high-pressure oil. The hydraulic assembly includes a reservoir 25 for receiving and storing oil. The hydraulic assembly includes a low-pressure pump 17 for drawing oil from the reservoir 25. The low-pressure pump 17 is fluidically connected to the reservoir 25 via a filter assembly 18. The low-pressure pump 17 is designed to pressurize the oil to low pressure. The low-pressure pump 17 is configured to deliver the low-pressure oil to a low-pressure path 23. For this purpose, the low-pressure pump 17 is fluidically connected to the low-pressure path 23 via a further filter assembly 18. The hydraulic assembly includes a filter bypass valve 16, which is configured to bypass the filter assembly 18 with at least a portion of the low-pressure oil when necessary. The hydraulic system includes a low-pressure lubrication point 21, in this case a differential gear of a driven axle unit. The low-pressure lubrication point 21 is fluidically connected to the low-pressure path 23 and is supplied with low-pressure oil. The hydraulic system includes a hydraulically operated working device 20 and a working pressure pump 19. The working device 20 is operable with working pressure oil. The working pressure pump 19 is fluidically connected to the low-pressure path 23 for receiving low-pressure oil. The working pressure pump 19 is designed to pressurize the low-pressure oil to the working pressure of the working pressure oil. The working pressure pump 19 is configured to deliver the working pressure oil to the working device 20. Working pressure oil consumed by the working device 20 is returned to the reservoir 25. The system pressure adjusting device 11 has a low-pressure interface 41 for receiving low-pressure oil from the low-pressure path 23. The system pressure adjusting device 11 is designed to pressurize the low-pressure oil to high pressure as high-pressure oil and to discharge the high-pressure oil via the high-pressure output interface 42. The hydraulic assembly includes a sensing device 32, which is configured to detect the actual temperature of the oil, in this case the low-pressure oil. In a further embodiment, the sensing device 32 is configured to detect the actual temperature of the oil in the reservoir 25. The sensing device 32 is also configured to detect an actual operating parameter. The actual operating parameter comprises a load state of a drive unit 60 of the machine, which is shown with reference to Fig. 4 and is configured as an internal combustion engine. The actual oil temperature and the actual operating parameter are transmitted to a vehicle control unit 33 and evaluated there. The vehicle control unit 33 is electrically connected to the sensing device 32. The actual oil temperature and the actual operating parameter are transmitted from the vehicle control unit 33 to a control unit 31 of the hydraulic assembly.The vehicle control unit 33 is electrically connected to the control device 31. The control device 31 is electrically connected to the cooler bypass valve 13 for adjusting the actual oil temperature to an adjustable target temperature based on the actual temperature and the actual operating parameters of the machine. The cooler bypass valve 13 comprises an electromagnetic valve unit 14 and a hydraulic valve unit 15. The hydraulic valve unit 15 has an inlet channel and an outlet channel, both of which are fluidically connected to the high-pressure path 22 for bypassing the cooler assembly 12. The hydraulic valve unit 15 has an actuation chamber through which a valve piston can be hydraulically moved from a closed position to an open position against a preload force. The electromagnetic valve unit 14 has an inlet channel and an outlet channel. The outlet channel of the electromagnetic valve unit 14 is fluidically connected to the actuation chamber of the hydraulic valve unit 15 to supply actuation oil at an actuation pressure. The inlet channel of the electromagnetic valve unit 14 is fluidically connected to the high-pressure path 22. In an open valve state, the inlet and outlet channels of the electromagnetic valve unit 14 are fluidically connected. The actuation chamber of the hydraulic valve unit 15 is supplied with high-pressure oil as actuation oil via the electromagnetic valve unit 14 when the electromagnetic valve unit 14 is in the open valve state. Thus, the electromagnetic valve unit 14 is configured to control the valve state of the hydraulic valve unit 15.The electromagnetic valve unit 14 is electrically connected to the control unit 31. The electromagnetic valve unit 14 can be electrically moved into the open valve state via the control unit 31. Fig. 2 is a schematic representation of another embodiment of the hydraulic arrangement. The present embodiment differs from the embodiment described with reference to Fig. 1 in that the cooler bypass valve 13 is designed as a proportional valve. This allows the oil flow rate to be variably adjusted depending on an electrical control current. As a result, the cooling capacity of the high-pressure oil passing through the cooler assembly 12 can be precisely adjusted. Fig. 3 is a schematic representation of another embodiment of the hydraulic arrangement. The present embodiment differs from the embodiment described with reference to Fig. 1 in that the system pressure adjusting device 11 includes a control pressure pump for pressurizing the low-pressure oil with a control pressure as control pressure oil. Switching elements of a transmission 50, shown with reference to Fig. 4, can be actuated via the control pressure oil. The system pressure adjusting device 11 outputs the control pressure to a control pressure path 24 via a control pressure interface 44. The input channel of the electromagnetic valve unit 14 is fluidically connected to the control pressure path 24. The actuation chamber of the hydraulic valve unit 15 is supplied with control pressure oil as actuation oil via the electromagnetic valve unit 14. Fig. 4 is a top view of a schematic representation of an embodiment of a working machine with the hydraulic arrangement described above. The working machine has the drive unit 60 with a drive shaft. The gearbox 50 has an input element 51 and an output element 52. The gearbox 50 has a transmission ratio from the input element 51 to the output element 52 that is adjustable via the system pressure adjusting device 11. The cooler 12 is connected to the system pressure adjusting device 11 via the high-pressure path 22 for cooling the high-pressure oil. The cooling capacity of the high-pressure oil routed through the cooler 12 can be adjusted as required via the electro-hydraulic cooler bypass valve 13. The drive shaft of the drive unit 60 is mechanically connected to the input element 51 for transmitting a drive force to the transmission 50. The working machine has two traction elements 70, which are mechanically connected to the output element 52 via the differential gear for driving the vehicle. The hydraulic arrangement also includes, among other things, the sensing device 32 for detecting the actual temperature and the actual operating parameter. Fig. 5 is a flowchart of an embodiment of a method for controlling the hydraulic arrangement. The method comprises, in a first step I, acquiring the actual temperature and the actual operating parameter using the acquiring device 32. In a second step II, the method comprises adjusting the actual temperature to an adjustable setpoint temperature by actuating the cooler bypass valve 13 as a function of the actual temperature, the setpoint temperature, and the actual operating parameter. Reference sign 11 System pressure adjusting device 12 Cooler device 13 Cooler bypass valve 14 Electromagnetic valve unit 15 Hydraulic valve unit 16 Filter bypass valve 17 Low-pressure pump 18 Filter device 19 Working pressure pump 20 Working device 21 Low-pressure lubrication point 22 High-pressure path 23 Low-pressure path 24 Control pressure path 25 Reservoir 31 Control device 32 Detection device 33 Vehicle control unit 41 Low-pressure interface 42 High-pressure output interface 43 High-pressure input interface 44 Control pressure interface 50 Transmission 51 Input element 52 Output element 60 Drive unit 70 Traction element

Claims

Hydraulic arrangement for a working machine, wherein the hydraulic arrangement comprises: a system pressure adjusting device (11) configured to discharge oil at a pressure as high-pressure oil to a high-pressure path (22), a cooler device (12) connected to the system pressure adjusting device (11) for cooling the high-pressure oil, and an electro-hydraulic cooler bypass valve (13) connected to the high-pressure path (22) for bypassing the cooler device (12) with at least a portion of the high-pressure oil, wherein an inlet channel and an outlet channel of the cooler bypass valve (13) are fluidically connected to the high-pressure path (22) for bypassing the cooler device (12) with at least a portion of the high-pressure oil. Hydraulic arrangement according to claim 1, characterized in that the hydraulic arrangement comprises: a detection device (32) which is configured to detect an actual temperature of the oil and an actual operating parameter of the working machine, and a control device (31) which is connected to the cooler bypass valve (13) for adjusting the actual temperature of the oil to an adjustable target temperature based on the actual temperature and the actual operating parameter of the working machine. Hydraulic arrangement according to one of the preceding claims, characterized in that the hydraulic arrangement comprises: a reservoir (25) designed to receive the oil, and a low-pressure pump (17) designed to supply the oil from the reservoir (25) with low pressure as low-pressure oil and to discharge the low-pressure oil to a low-pressure path (23), wherein the system pressure adjusting device (11) is connected to the low-pressure path (23) for receiving the low-pressure oil and is designed to supply the low-pressure oil with high pressure as high-pressure oil. Hydraulic arrangement according to one of the preceding claims, characterized in that the cooler bypass valve (13) is designed as a proportional valve. Hydraulic arrangement according to one of the preceding claims, characterized in that the cooler bypass valve (13) is designed as an indirect valve, comprising a hydraulic valve unit (15) which has an open valve state in which the hydraulic valve unit (15) is configured to bypass the cooler device (12) with at least a part of the high-pressure oil from the high-pressure path (22), and comprising an electromagnetic valve unit (14) which is configured to dispense oil at an actuating pressure as actuating oil for adjusting the valve state of the hydraulic valve unit (15). Hydraulic arrangement according to claim 5, characterized in that the electromagnetic valve unit (14) is connected to the high-pressure path (22) for receiving high-pressure oil and is configured to discharge the high-pressure oil to the hydraulic valve unit (15) as actuating oil. Hydraulic arrangement according to claim 5, characterized in that the system pressure adjusting device (11) is designed to supply oil with a control pressure as control pressure oil to a control pressure path (24) and the electromagnetic valve unit (14) is connected to the control pressure path (24) for receiving control pressure oil and is configured to supply the control pressure oil to the hydraulic valve unit (15) as actuating oil. Gearbox (50) comprising a hydraulic arrangement according to one of claims 1 to 7, a hydraulic consumer connected to the high-pressure path (22) for receiving high-pressure oil, an input element (51) for receiving a drive force and an output element (52) for outputting a drive force, wherein the gearbox (50) provides a transmission ratio from the input element (51) to the output element (52). Working machine comprising a gearbox (50) according to claim 8, a drive unit (60) which is mechanically connected to the input element (51) of the gearbox (50) for the purpose of applying a drive force, and a traction element (70) which is mechanically connected to the output element (52) of the gearbox (50) for the purpose of moving the working machine. Method for controlling a hydraulic arrangement according to one of claims 1 to 7, wherein the method comprises: detecting (I) the actual temperature and the actual operating parameter with the detection device (32), adjusting (II) the actual temperature to an adjustable target temperature by actuating the cooler bypass valve (13) depending on the actual temperature and the actual operating parameter.

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