Controller for a vehicle with a steering device, steering device and method for heating a working medium in a warm-up phase of the steering device

Abstract

A control (110) for a vehicle (100) having a steering device (102) with a pump device (104) comprising a pump (112) and an electric motor (118), a transmission (106), a valve (108) and a control (110), which is configured for supplying a motor signal (140) for operating the electric motor (118) of the steering device (102) to the electric motor (118) and a valve opening signal (142) for opening the valve (108) of the steering device (102) to the valve (108) in a preheating phase for heating the working medium.

Description

Technical Field

[0001] This solution relates to a controller for a vehicle with a steering system, a steering system, and a method for heating a working medium during the preheating phase of the steering system. Background Technology

[0002] In vehicle steering systems, especially in the front axle steering systems (also known as power steering systems) of medium and heavy-duty commercial vehicles, recirculating ball steering systems (Kugelumlauf-Lenkgetriebe) can be operated by an external one-way hydraulic pump. The connection between the pump and the steering transmission can be achieved, for example, through external piping. Additionally, an external reservoir is required as a compensation container. Therefore, the various components of this steering system can be distributed throughout the vehicle.

[0003] DE202019101 522U1 discloses a corresponding steering support device for vehicles, particularly for commercial motor vehicles. Summary of the Invention

[0004] In this context, the objective of this solution is to implement an improved controller for a vehicle with a steering system, an improved steering system, and an improved method for heating the working medium during the preheating phase of the steering system.

[0005] This task is accomplished by a controller having the features of the device of the present invention, by a steering device according to the present invention, and by a method according to the present invention.

[0006] The advantages that can be achieved by using the proposed scheme include, for example, improved starting performance of the steering system during cold starts of the vehicle.

[0007] A controller for a vehicle including a steering system is proposed. The steering system has a pump assembly having a pump for pumping a working medium to a first output connector or a second output connector, and an electric motor for driving the pump. Furthermore, the steering system has a transmission assembly having an input shaft coupled to a steering wheel and an output shaft coupled to a steering arm, and a transmission element movable in a first and a second direction for transmitting torque from the input shaft to the output shaft. The steering system also includes a first working medium connector and a second working medium connector, wherein the first working medium connector is connected to the first output connector to allow the transmission element to move in the first direction when using the working medium, and the second working medium connector is connected to the second output connector to allow the transmission element to move in the second direction when using the working medium. Additionally, the steering system has a valve connected between the first and second output connectors. Here, the controller is configured to provide a motor signal for operating the electric motor of the steering system and a valve opening signal for opening the valve of the steering system during a preheating phase for heating the working medium.

[0008] The vehicle is implemented, for example, as a commercial vehicle, such as a truck or bus. The steering system is advantageously used to implement the driver's steering request and, additionally, to support that steering request when using a working medium. The transmission is configured to transmit, for example, the driver's steering motion via the steering wheel to the steering arms and thus to, for example, the vehicle's axles. The pump can be implemented, for example, as a hydraulic pump, which can pump a working medium, such as hydraulic oil, through a pumping device. A valve, for example, can also be used as a backup valve to bypass the transmission. If the valve is open, the working medium pumped by the pumping device can be guided past the transmission via the valve. Therefore, the pumping device can operate during a preheating phase, but cannot provide steering support. The pumping device can be operated in this way without causing steering motion. The heat generated in the pumping device can be used to heat the working medium. Advantageously, this can improve the viscosity of the working medium, for example, before the vehicle is driven. The preheating phase can continue after the steering system is engaged until the working medium has reached a predetermined operating temperature. The warm-up phase can be followed by a normal operation phase, in which the steering mechanism can operate to support steering; alternatively, if steering support is not required, the warm-up phase can be followed by a stationary phase, for example, since the vehicle is not yet moving. The controller can be configured to provide appropriate motor control signals based on the current operating phase of the steering mechanism.

[0009] According to one embodiment, the controller can be configured to, during normal operation, provide a motor signal to the electric motor for operating the electric motor to move the steering arm and a valve closing signal to the valve for closing the valve. The normal operation phase can describe, for example, a state where the vehicle is moving and steering support is provided. Depending on the embodiment, the valve opening signal and the valve closing signal can be separate signals or different states of a single signal.

[0010] According to one embodiment, the controller can be configured to provide a motor signal during the preheating phase that induces a current flow through the motor windings of the electric motor without causing rotation of the motor rotor. For example, the motor signal can have the characteristic of preventing the electric motor from starting. The motor windings are heated by the current flow. Therefore, the electric motor can be used as a heating device for heating the medium when the pump is not driven.

[0011] According to one embodiment, the controller can be configured to provide a motor signal during the preheating phase that induces a first-sized current flow through the motor windings, causing the rotor to rotate at a first speed. Furthermore, the controller can be configured to provide a motor signal during the normal operating phase that induces the same first-sized current flow through the motor windings, causing the rotor to rotate at a second speed, greater than the first speed. Therefore, the electric motor can operate during the preheating phase such that it has lower efficiency in terms of the torque provided by the electric motor compared to the normal operating phase. Advantageously, a larger proportion of electrical energy is converted into heat energy during the preheating phase compared to the normal operating phase.

[0012] The controller can be configured to activate a preheating phase in response to a temperature signal indicating a temperature below a threshold. This threshold can be associated with a specific viscosity of the working medium. This threshold can be below or at the optimal operating temperature of the working medium. The temperature can be sensed, for example, using a temperature sensor. Therefore, the preheating phase can only be implemented when heating of the working medium is favorable. For example, if the temperature signal indicates a predetermined temperature of the working medium, the preheating phase can be terminated.

[0013] According to one embodiment, the controller can be configured to activate a preheating phase in response to a start signal indicating a cold start of the vehicle. This means that the start signal is provided, for example, when the vehicle is started for the first time after a prolonged period of parking. In such a case, the working medium can be assumed to still be at the desired operating temperature. Similarly, the preheating phase can be terminated if the temperature signal indicates a predetermined temperature of the working medium.

[0014] Furthermore, a steering device for a vehicle is proposed, wherein the steering device has a pump device for pumping torque. The steering device also has a transmission device having an input shaft coupled to a steering wheel and an output shaft coupled to a steering arm, a transmission element movable in a first and a second direction for transmitting torque from the input shaft to the output shaft, and a first working medium connector and a second working medium connector. Here, the first working medium connector is connected to the first output connector to allow the transmission element to move in the first direction using a working medium, and the second working medium connector is connected to the second output connector to allow the transmission element to move in the second direction using a working medium. The steering device also has a valve and, in the proposed variant, a controller connected between the first and second output connectors.

[0015] The steering device can be implemented, for example, as a steering transmission, as is used in, for example, commercial vehicles. Advantageously, this supports the driver's steering movements.

[0016] In one embodiment, the motor windings of the electric motor are surrounded by a working medium. Advantageously, this enables good thermal coupling because the working medium can be directly heated by the motor windings.

[0017] According to one embodiment, the pump and the electric motor can share a common shaft and be arranged in a common housing. This advantageously saves structural space within the vehicle, as only one housing is installed instead of two.

[0018] The housing can have a channel for guiding the working medium from the inlet along the inner wall of the housing to the motor windings. Here, the channel can be configured to guide the working medium around the motor windings. Advantageously, the working medium is heated uniformly in this way. The channel can be configured, for example, as a groove or recess in a housing element or can also be tubular. The inlet can, for example, represent an interface between the pump and the channel, or alternatively, an interface between the storage tank and the pump assembly. Advantageously, the arrangement of the channel allows the motor windings to be cooled by means of the working medium.

[0019] According to one embodiment, the rotor of the electric motor can have a plurality of permanent magnets, wherein adjacent permanent magnets are spaced apart by gaps for guiding the working medium through.

[0020] According to one embodiment, the gap can be configured to deliver the working medium as the rotor rotates. Therefore, the gap between the permanent magnets can induce circulation of the working medium.

[0021] According to one embodiment, the pump can be configured as a bidirectional hydraulic pump. Advantageously, in this way, it is also possible to easily output the working medium depending on the desired delivery direction of the working medium.

[0022] Furthermore, a method for heating the working medium during the preheating stage of the steering device in one of the aforementioned variations is proposed. Here, the method includes the steps of providing a motor signal to the electric motor of the steering device to operate the electric motor and providing a valve opening signal to the valve of the steering device to open the valve.

[0023] This method can be implemented, for example, in the steering system using a controller as described in one of the aforementioned variations. Advantageously, the viscosity of the working medium can be reduced by the heat generated during the operation of the electric motor, without applying torque to the steering tie rod of the steering system. Through an open valve, the working medium can circulate in the steering system's lines, allowing as much of the working medium as possible to be heated.

[0024] This method can be implemented, for example, in software, hardware, or a hybrid of both, such as in a controller. The controller can be configured to execute, manipulate, or implement variations of the method presented herein within a suitable device. This implementation variation, in the form of a device, also enables the rapid and efficient resolution of the task on which the solution is based.

[0025] The controller may have: at least one computing unit for processing signals or data; at least one storage unit for storing signals or data; at least one interface for reading sensor signals from a sensor or outputting data signals or control signals to an actuator; and / or at least one communication interface for reading or outputting data embedded in a communication protocol. The computing unit may be, for example, a signal processor, a microcontroller, etc., wherein the storage unit may be flash memory, EPROM, or magnetic storage. The communication interface may be configured for wirelessly and / or wiredly reading or outputting data, wherein a communication interface capable of reading or outputting wired data may, for example, electrically or optically read such data from a corresponding data transmission line or output such data to a corresponding data transmission line.

[0026] Currently, a "controller" can be understood as an electrical device that processes sensor signals and outputs control and / or data signals based on those signals. A controller can have an interface, which can be constructed in hardware and / or software. In a hardware construction, the interface can, for example, be part of a so-called system ASIC that contains various functions of the controller. However, it is also possible that the interface is its own integrated circuit or at least partially composed of discrete components. In a software construction, the interface can be a software module, which, among other software modules, may also exist on a microcontroller, for example. Attached Figure Description

[0027] Embodiments of the proposed solutions are described in more detail below with reference to the accompanying drawings. The drawings show:

[0028] Figure 1 A schematic illustration of a vehicle with a steering device according to one embodiment;

[0029] Figure 2 A schematic cross-sectional view of a pump device according to one embodiment; and

[0030] Figure 3 A flowchart of a method for heating a working medium in a preheating phase of a steering device, according to one embodiment. Detailed Implementation

[0031] In the following description of advantageous embodiments of this solution, the same or similar reference numerals are used for elements shown in different figures and functioning similarly, wherein repeated descriptions of these elements are omitted.

[0032] Figure 1 A schematic illustration of a vehicle 100 having a steering device 102 according to one embodiment is shown. The vehicle 100 is, for example, a commercial vehicle. The steering device 102 is configured to support the steering process of the driver of the vehicle 100. For this purpose, the steering device 102 has a pump device 104, a transmission device 106, a valve 108, and a controller 110.

[0033] Here, the pump assembly 104 includes a pump 112 for pumping the working medium to a first output connector 114 or a second output connector 116 of the pump assembly 104. Furthermore, the pump assembly 104 includes an electric motor 118 configured to drive the pump 112. For this purpose, the electric motor 118 and the pump 112 are coupled to each other via shafts. The pump 112 is, for example, implemented as a bidirectional hydraulic pump.

[0034] The transmission 106 has an input shaft 120 that can be coupled to a steering wheel and an output shaft 124 that can be coupled to a steering arm 122. Furthermore, the transmission 106 has a transmission element 130 movable along a first direction 126 and a second direction 128 for transmitting torque from the input shaft 120 to the output shaft 124. The transmission 106 also includes a first working medium connector 132 and a second working medium connector 134, wherein the first working medium connector 132 is connected to a first output connector 114 to allow the transmission element 130 to move along the first direction 126 when using a working medium, and the second working medium connector 134 is connected to a second output connector 116 to allow the transmission element 130 to move along the second direction 128 when using a working medium. To allow the transmission element 130 to move when using a working medium, according to one embodiment, at least one cylinder is provided, configured to move the transmission element 130 using the pressure of the working medium.

[0035] According to this embodiment, the input shaft 120 is configured to be connected or mechanically coupled to the steering wheel 119 of the vehicle 100 via the steering column of the steering system. According to one embodiment, the input shaft 120 is configured to introduce torque from the steering column of the vehicle 100, coupled to the steering wheel 119, into the steering mechanism 102. The torque introduced via the input shaft 120 may also be referred to as input torque. According to this embodiment, the output shaft 124 is configured to derive torque from the steering mechanism 102, or to output torque to the steering arm 122. The torque derived via the output shaft 124 may also be referred to as output torque or output force. According to this embodiment, the transmission element 130 is configured to mechanically transmit torque from the input shaft 120 to the output shaft 124 and / or convert input torque into output torque. To support steering movements applied by the driver of the vehicle 100, the movement of the transmission element 130 is supported using a working medium. Accordingly, the transmission element 130 can move in an automated steering vehicle 100 using only the pressure of the working medium.

[0036] The valve 108 of the steering device 102 is connected between the first output connector 114 and the second output connector 116. According to this embodiment, the first valve connector 136 of the valve 108 is fluidly connected to the first output connector 114 and the first working medium connector 132. Similarly, according to this embodiment, the second valve connector 138 of the valve 108 is fluidly connected to the second output connector 116 and the second working medium connector 134.

[0037] The steering system 102 also includes a controller 110 configured to determine the current operating phase of the steering system 102 and, based on the current operating phase, provide appropriate motor signals 140 for operating the electric motor 118 and appropriate valve signals 142, 144 for controlling the valves 108. According to one embodiment, the controller 110 is configured to initiate a preheating phase, for example, to reduce the viscosity of the working medium, when heating the working medium is advantageous. The controller 110 can be configured to maintain the preheating phase until the working medium is heated to a predetermined temperature. Immediately following the preheating phase, the controller 110, according to one embodiment, is configured to initiate a normal operating phase in which steering support is provided by the steering system 102, for example, for normal driving operation of the vehicle 100. Here, steering support can be provided in response to a request signal indicating, for example, steering requested by the driver of the vehicle 100 and a steering direction 146 of the vehicle 100. Depending on the requested steering direction 146, the controller 110 is configured, according to one embodiment, to provide a motor signal 140 having characteristics that cause the electric motor 112 to rotate in a direction corresponding to the steering direction 146.

[0038] According to one embodiment, controller 110 is configured to provide motor signal 140 and valve signals 142, 144 during a preheating phase such that electric motor 118 is operated, i.e., energized, but without providing steering support, for example because no pressure is applied at working medium joints 132, 134, or only insufficient pressure is applied to move transmission element 130. For this purpose, the provided motor signal 140 has, for example, a characteristic that causes a current to flow through at least one winding of electric motor 118, generating a magnetic field unsuitable for moving the rotor of electric motor 118. Alternatively, the provided motor signal 140 has, for example, a characteristic that causes a current to flow through at least one winding of electric motor 118, generating a magnetic field suitable for moving the rotor of electric motor 118. In this case, controller 110 is configured to provide a valve signal in the form of valve opening signal 142 for opening valve 108. The characteristics of motor signal 140 may, for example, involve the amplitude and / or modulation of motor signal 140.

[0039] According to one embodiment, controller 110 is configured to provide a motor signal 140 during normal operation with characteristics that ensure the electric motor 112 is suitable for driving the pump 118. Furthermore, controller 110 is configured to provide a valve signal, in the form of a valve closing signal 144 for closing valve 108, to valve 108. In this way, a pressure sufficient to support directional movement of the working medium is generated, and this pressure is applied to one of the working medium connectors 132, 134 depending on the delivery direction of the pump assembly 104.

[0040] A portion of the electrical energy supplied to the electric motor 118 via motor signal 140 is converted into heat, and another portion is used to drive the rotor of the electric motor 118. According to one embodiment, controller 110 is configured to provide motor signal 140 such that the ratio of the portion of the electrical energy supplied to the electric motor 118 converted into heat to the portion used for driving is greater during the preheating phase than during the normal operation phase. According to one embodiment, controller 110 is configured to provide motor signal 140 during the preheating phase with a characteristic that causes a first-magnitude current flow through the motor windings, which generates a first magnetic field causing the rotor to rotate at a first speed. During the normal operation phase, controller 110 is configured to provide motor signal 140 with a characteristic that causes a first-magnitude current flow through the motor windings, which generates a second magnetic field causing the rotor to rotate at a second speed, which is greater than the first speed. Therefore, it is possible to...

[0041] According to one embodiment, controller 110 is configured to activate a preheating phase in response to a temperature signal 152 indicating a temperature of the working medium below a threshold. According to this embodiment, the temperature signal 152 is provided by a temperature sensor 154. According to this embodiment, the temperature sensor 154 is implemented as part of the pump assembly 104. Alternatively, the temperature sensor 154 may also be arranged in other ways in the vehicle 100. For example, controller 110 is configured to end the preheating phase once the temperature signal 152 indicates that the working medium is at or above a threshold temperature. Alternatively or additionally, controller 110 may be configured, for example, to end the preheating phase after a defined duration.

[0042] According to this embodiment, the controller 110 is additionally or alternatively configured to activate a warm-up phase in response to a start signal 160 indicating a cold start of the vehicle 100. The start signal 160 is provided, for example, by a motor control device of the vehicle 100.

[0043] According to the illustrated embodiment, the pump assembly 104 has an optional inlet connector 156, via which the pump assembly 104 is connected to a storage tank 158 for storing the working medium.

[0044] In other words, a possibility is proposed for preheating the working medium during the cold start of vehicle 100, which can also be realized as hydraulic oil and can be referred to as oil. This means that for applications that steer vehicle 100, such as a truck, an electro-hydraulic steering transmission (also referred to herein as transmission 106) is operated via a bidirectional pump device 104, which has a hydraulic pump, for example, in the form of pump 112. Two joints of pump device 104 are connected to transmission 106, for example to at least one cylinder of a conventional known steering transmission, the two joints here referring to a first output joint 114 and a second output joint 116. According to one embodiment, the electric motor 118 driving pump 112 is surrounded by the working medium in a storage tank 158, also referred to herein as a storage container or expansion tank. Before driving begins, it is possible to improve the viscosity of the working medium by appropriately manipulating the electric motor 118 by increasing the temperature of the working medium.

[0045] According to one embodiment, the electric motor 118 rotates by opening the valve 118 without moving the steering arm 122. Thus, the heated working medium is distributed in the pump assembly 104. The motor windings of the electric motor 118 can be optionally controlled so that the motor windings become significantly hot even when stationary or at low motor power.

[0046] Figure 2 A schematic cross-sectional view of a pump assembly 104 according to one embodiment is shown. The pump assembly 104 shown herein may be similar to or correspond to... Figure 1 The pump assembly 104 is described in the text. According to this embodiment, the pump 112 and the electric motor 118 are arranged adjacent to each other in a common housing 200. The housing 200 surrounds the pump 112, the electric motor 118, and a common shaft 201 coupled to the electric motor 118. Here, the working medium delivered by the pump 112 is guided through the housing 200 such that the working medium is heated by the electric motor 118.

[0047] The electric motor 118 includes a rotor 202 and a stator 203. The rotor 202 has a plurality of permanent magnets, wherein adjacent permanent magnets are spaced apart by a slit 204 for guiding the working medium through. The slit 204 is configured in this way to deliver the working medium as the rotor 202 rotates.

[0048] According to this embodiment, the housing 200 has a channel 206 for guiding the working medium from the inlet along the inner wall of the housing 200 to the motor winding 208 arranged on the stator 203 of the electric motor 118. Here, the channel 206 is configured to guide the working medium around the motor winding 208. Here, the flow direction of the working medium is indicated by the drawn arrow 210. According to this embodiment, it is also shown that the motor winding 208 is surrounded by the working medium in order to achieve, for example, good thermal coupling.

[0049] In summary, pump 112 pumps the working medium from pump output 212 through channel 206 along the wall of housing 200 in the direction toward motor winding 208, where, according to one embodiment, the working medium is cooled. From there, the working medium flows around motor winding 208 according to this embodiment and through slot 204, which serves as a circulation pump, in the direction toward housing wall until it reaches pump output 212 via, for example, heat exchanger 214.

[0050] In other words, the electric motor 118 serves as a heating device to preheat the working medium when the ambient temperature is cold, for example. The motor winding 108, embedded in the working medium, achieves good thermal coupling between the electric motor 118 and the surrounding working medium. The gap 204 between the multiple permanent magnets on the rotor 202 (also called the rotor disc) serves as a drive mechanism for circulating the working medium. The working medium, circulating in the direction of arrow 210, flows through the coils of the electric motor 118 forming the motor winding 108 and becomes heated therein.

[0051] Figure 3 A flowchart illustrates a method 300 for heating a working medium during a preheating phase of a steering device, according to one embodiment. Method 300 is capable of, as in... Figure 1 This is executed in the controller already described. Here, method 300 includes step 302 of providing a motor signal to the electric motor of the steering device to operate the electric motor, and step 304 of providing a valve opening signal to the valve of the steering device to open the valve. Steps 302 and 304 are performed in a preheating phase, which is executed to heat the working medium. During the duration of the preheating phase, the valve is continuously opened according to one embodiment. According to one embodiment, the electric motor is specifically operated during the preheating phase to heat the working medium, during which no steering support is provided.

[0052] Optionally, method 300 includes step 306 of providing a motor signal having the same or modified characteristics as step 302 and step 308 of providing a valve closing signal to close the valve. Steps 306 and 308 are performed during normal operation, in which the working medium is under pressure to steer or support steering of the vehicle.

[0053] According to one embodiment, method 300 includes a step 310 of reading a temperature signal indicating the temperature of the working medium. According to one embodiment, step 310 is performed repeatedly to continuously monitor the temperature of the working medium. According to one embodiment, a preheating phase continues when the temperature signal indicates a working medium temperature below a predetermined operating temperature. For example, after the vehicle is put into operation, it is checked whether the working medium temperature has reached the operating temperature. If so, the preheating phase is skipped and the normal operation phase is initiated directly. Conversely, if the working medium temperature is below the operating temperature, a preheating phase is performed before the start of the normal operation phase to raise the working medium temperature to the operating temperature.

[0054] List of reference numerals

[0055] 100 vehicles

[0056] 102 Steering mechanism

[0057] 104 Pump Unit

[0058] 106 Transmission device

[0059] 108 valve

[0060] 110 Controller

[0061] 112 pump

[0062] 114 First Output Connector

[0063] 116 Second Output Connector

[0064] 118 electric motor

[0065] 119 Steering Wheel

[0066] 120 input axis

[0067] 122 Steering arm

[0068] 124 Output Shaft

[0069] 126 First Direction

[0070] 128 Second Direction

[0071] 130 Transmission Components

[0072] 132 First working medium connector

[0073] 134 Second Working Medium Connector

[0074] 136 First Valve Connector

[0075] 138 Second Valve Connector

[0076] 140 Motor Signal

[0077] 142 Valve Open Signal

[0078] 144 Valve Close Signal

[0079] 146 Turning direction

[0080] 148 Steering tie rod

[0081] 150 wheels

[0082] 152 Temperature Signal

[0083] 154 Temperature Sensor

[0084] 156 Input Connector

[0085] 158 storage tanks

[0086] 160 Start Signal

[0087] 200 housing

[0088] 201 shaft

[0089] 202 Rotor

[0090] 203 Stator

[0091] 204 gaps

[0092] Channel 206

[0093] 208 motor winding

[0094] 210 Arrow

[0095] 212 Pump output end

[0096] 214 Heat Exchanger

[0097] 300 methods

[0098] 302 Steps for providing motor signals

[0099] 304 Steps for providing a valve opening signal

[0100] 306 Steps for providing motor signals

[0101] 308 Steps for providing a valve closing signal

[0102] 310 Reading Steps

Claims

1. A controller (110) for a vehicle (100) having a steering device (102), the steering device comprising: - a pump assembly (104) having a pump (112) for pumping a working medium to a first output connector (114) or a second output connector (116) of the pump assembly (104) and an electric motor (118) for driving the pump (112), wherein the pump (112) and the electric motor (118) have a common shaft and are arranged in a common housing (200), wherein, The housing (200) has a channel (206) for guiding the working medium from the inlet along the inner wall of the housing (200) to the motor winding (208), and wherein the channel (206) is configured to guide the working medium around the motor winding (208), wherein the rotor (202) of the electric motor (118) has a plurality of permanent magnets, wherein adjacent permanent magnets are spaced apart by slits (204) through which the working medium is guided; A transmission device (106) having an input shaft (120) coupled to a steering wheel (119) and an output shaft (124) coupled to a steering arm (122), a transmission element (130) movable in a first direction (126) and a second direction (128) for transmitting torque from the input shaft (120) to the output shaft (124), and a first working medium connector (132) and a second working medium connector (134), wherein the first working medium connector (132) is connected to the first output connector (114) to allow the transmission element (130) to move in the first direction (126) using the working medium, and the second working medium connector (134) is connected to the second output connector (116) to allow the transmission element (130) to move in the second direction (128) using the working medium; and - A valve (108) is connected between the first output connector (114) and the second output connector (116), wherein the controller (110) is configured to provide a motor signal (140) for operating the electric motor (118) of the steering device (102) during a preheating phase for heating the working medium, such that the electric motor has a lower efficiency than during normal operation, and to provide a valve opening signal (142) for opening the valve (108) of the steering device (102) so that the pump device can be operated without causing steering movement.

2. The controller (110) according to claim 1, wherein, The controller (110) is configured to provide the motor signal (140) for operating the electric motor (118) and the valve closing signal (144) for closing the valve (108) in order to move the steering arm (122) during normal operation.

3. The controller (110) according to claim 1 or 2, wherein the controller is configured to provide a motor signal (140) during the preheating phase as a signal that causes current flow through the motor windings (208) of the electric motor (118) without causing rotation of the rotor (202) of the electric motor (118).

4. The controller (110) according to claim 3, wherein the controller is configured to provide a motor signal (140) during the preheating phase to cause a first-magnitude current flow through the motor windings (208) causing the rotor (202) to rotate at a first speed, and the controller is configured to provide a motor signal (140) during the normal operation phase to cause a first-magnitude current flow through the motor windings (208) causing the rotor (202) to rotate at a second speed greater than the first speed.

5. The controller (110) according to claim 1 or 2, wherein the controller activates the preheating phase in response to a temperature signal (152) indicating a temperature below a threshold.

6. The controller (110) according to claim 1 or 2, wherein the controller activates the preheating phase in response to a start signal (160) indicating a cold start of the vehicle (100).

7. A steering device (102) for a vehicle (100), wherein, The steering device (102) has the following features: - Pump assembly (104), the pump assembly having a pump (112) for pumping the working medium to a first output port (114) or a second output port (116) of the pump assembly (104) and an electric motor (118) for driving the pump (112); - A transmission device (106) having an input shaft (120) coupled to a steering wheel (119) and an output shaft (124) coupled to a steering arm (122), a transmission element (130) movable in a first direction (126) and a second direction (128) for transmitting torque from the input shaft (120) to the output shaft (124), and a first working medium connector (132) and a second working medium connector (134), wherein the first working medium connector (132) is connected to the first output connector (114) for the transmission element (130) to move in the first direction (126) when using the working medium, and the second working medium connector (134) is connected to the second output connector (116) for the transmission element (130) to move in the second direction (128) when using the working medium; a valve (108) connected between the first output connector (114) and the second output connector (116); and - The controller (110) according to any one of the preceding claims.

8. The steering device (102) according to claim 7, wherein, The motor windings (208) of the electric motor (118) are surrounded by the working medium.

9. The steering device (102) according to claim 7 or 8, wherein, The gap (204) between the plurality of permanent magnets of the rotor (202) of the electric motor (118) is configured to deliver the working medium when the rotor (202) rotates.

10. The steering device (102) according to claim 7 or 8, wherein, The pump (112) is configured as a bidirectional hydraulic pump.

11. A method (300) for heating a working medium during a preheating phase of a steering device (102) according to any one of claims 7 to 10, wherein, The method (300) includes the following steps: - providing a motor signal (140) to the electric motor (118) of the steering device (102) to operate the electric motor (118); and - providing a valve opening signal (142) to the valve (108) of the steering device (102) to open the valve (108).

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