Control device for a vehicle with a steering gear, steering gear and method for heating a working medium in a preheating phase for a steering gear - Patents.com

Abstract

A control device (110) for a vehicle (100) having a steering device (102), the steering device (102) comprising a pump device (104) including a pump (112) and an electric motor (118), a transmission device (106), a valve (108), and a control device (110), the control device (110) being configured to supply a motor signal (140) to the electric motor (118) of the steering device (102) for operating the electric motor (118) and to supply a valve opening signal (142) to the valve (108) of the steering device (102) for opening the valve (108) during a pre-heating phase for heating a working medium.

Description

[Technical field]

[0001] The approach relates to a control device for a vehicle with a steering arrangement, to a steering arrangement and to a method for heating a working medium in a pre-heating phase for a steering arrangement.

[0002] In vehicle steering systems, in particular in front-axle steering systems, also called power steering, of medium- and heavy-duty commercial vehicles, for example a recirculating ball steering gear can be actuated by a one-way external hydraulic pump. The connection between the pump and the steering gear can be effected, for example, by external piping. In addition, an external oil reservoir may be required as a compensation vessel. This allows the individual components of such a steering system to be distributed around the vehicle.

[0003] DE 202019101522 A1 discloses a corresponding steering assist device for vehicles, in particular for commercial vehicles.

[0004] Against this background, the object of the present approach is to create an improved control device for a vehicle with a steering arrangement, an improved steering arrangement, and an improved method for heating a working medium in a pre-heating phase for a steering arrangement.

[0005] This problem is solved by a control device having the features of device claim 1, by a steering device according to claim 7 and by a method according to claim 14.

[0006] An advantage achievable with the presented approach is, for example, improved starting characteristics of the steering system during a cold start of the vehicle.

[0007] In the present invention, a control device for a vehicle including a steering device is presented. The steering device has a pump device with a pump for pumping a working medium to a first discharge port or a second discharge port of the pump device, and an electric motor for driving the pump. The steering device further has a transmission device with an input shaft connectable to a steering wheel, an output shaft connectable to a pitman arm, and a transmission element moving in a first direction and a second direction to transmit torque from the input shaft to the output shaft. The steering device further includes a first working medium port and a second working medium port, the first working medium port being connected to the first discharge port for moving the transmission element in the first direction using the working medium, and the second working medium port being connected to the second discharge port for moving the transmission element in the second direction using the working medium. The steering device further has a valve connected between the first discharge port and the second discharge port. The control device is configured to provide a motor signal to the electric motor for operating the electric motor of the steering device and a valve opening signal to open the valve of the steering device in a preheating phase for heating the working medium.

[0008] The motor vehicle is realized, for example, as a commercial vehicle, for example a lorry or a bus. The steering device can be advantageously used to realize the steering request of the driver of the vehicle and to additionally assist it with the working medium. The transmission is designed, for example, to transmit the steering movement of the driver via the steering wheel to a pitman arm and thus, for example, to the axles of the vehicle. The pump can be realized, for example, as a hydraulic pump, which can pump the working medium, for example hydraulic oil, by means of the pump device. A bypass of the transmission is possible, for example, by means of a valve which can also be used as a back-up valve. When the valve is open, the working medium pumped by the pump device can pass through the valve to the transmission. In this way, the pump device can be operated in a pre-heating phase, but without providing steering assistance. In this way, the pump device can be operated without generating a steering movement. The heat generated in the pump device can be used to heat the working medium. This can advantageously be used, for example, to improve the viscosity of the working medium before the vehicle is driven. The pre-heating phase can last until the working medium reaches a predetermined working temperature after the steering device starts to operate. The pre-heating phase can be followed by a normal operation phase in which the steering device is operable to assist steering, or by a stationary phase if no steering assistance is required, for example because the vehicle is not yet in motion. The control device can be configured to provide appropriate motor control signals depending on the actual operating phase of the steering device.

[0009] According to one embodiment, the controller can be configured to provide a motor signal to the electric motor to operate the electric motor and a valve closing signal to close the valve to move the pitman arm during a normal operating phase. The normal operating phase may represent, for example, a condition when the vehicle is being driven and steering assistance is provided. Depending on the embodiment, the valve opening signal and the valve closing signal may be separate signals or different states of one signal.

[0010] According to one embodiment, the control device can be configured to provide a motor signal during the pre-heating phase, which signal induces a current through the motor windings of the electric motor, without this current resulting in a rotation of the rotor of the electric motor. For example, the motor signal can have a characteristic that prevents the electric motor from starting. The current causes the motor windings to heat up. This allows the electric motor to be used as a heating device for heating the medium without the need to drive the pump.

[0011] According to one embodiment, the control device can be configured to provide a motor signal during the preheating phase as a signal for causing a first amount of current through the motor windings, which results in a rotation of the rotor with a first rotational speed. Furthermore, the control device can be configured to provide a motor signal during the normal operation phase as a signal for causing a first amount of current through the motor windings, which results in a rotation of the rotor with a second rotational speed higher than the first rotational speed. This allows the electric motor to be operated in the preheating phase with a lower efficiency for the torque provided by the electric motor than in the normal operation phase. Advantageously, a larger proportion of electrical energy is converted into thermal energy during the preheating phase than in the normal operation phase.

[0012] The control device can be configured to activate the pre-heating phase in response to a temperature signal indicating a temperature below a threshold value. The threshold value can be associated with a particular viscosity of the working medium. The threshold value can be below an optimal operating temperature or at an optimal operating temperature of the working medium. The temperature can be detected, for example, by a temperature sensor. This allows the pre-heating phase to be performed only if heating of the working medium is advantageous. For example, the pre-heating phase can be terminated if the temperature signal indicates a predetermined temperature of the working medium.

[0013] According to one embodiment, the control device can be configured to activate the pre-heating 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 starting the vehicle for the first time after a relatively long standstill. In such a case, it can be assumed that the working medium is not yet at the desired operating temperature. The pre-heating phase can also be terminated, for example, if the temperature signal indicates a predetermined working medium temperature.

[0014] Further, a steering device for a vehicle is presented, which has a pump device with a pump for pumping a working medium to a first or second outlet port of the pump device and an electric motor for driving the pump. The steering device further has a transmission device with an input shaft connectable to a steering wheel and an output shaft connectable to a pitman arm, a transmission element moving in a first direction and a second direction to transmit torque from the input shaft to the output shaft, and a first working medium port and a second working medium port. The first working medium port is connected to the first outlet port for moving the transmission element in the first direction using the working medium, and the second working medium port is connected to the second outlet port for moving the transmission element in the second direction using the working medium. The steering device further has a valve connected between the first outlet port and the second outlet port and a control device of one of the previously shown variants.

[0015] The steering system can be realized, for example, as a steering transmission, such as can be used, for example, in commercial vehicles, and is advantageously used to assist the driver in steering movements.

[0016] According to one embodiment, the motor windings of the electric motor may be surrounded by the working medium, which advantageously allows for good thermal coupling since the working medium can be heated directly by the motor windings.

[0017] According to one embodiment, the pump and the electric motor have a common shaft and can be arranged in a common casing, which advantageously allows to save installation space in the vehicle, since only one casing is installed instead of two.

[0018] The casing may have a passage for conducting the working medium from the inlet along the inner wall of the casing to the motor windings. The passage can be designed to conduct the working medium around the motor windings. This advantageously results in the working medium being heated evenly. The passage can be designed, for example, as a groove or recess in the casing element or also in the form of a tube. The inlet can represent, for example, the interface between the pump and the passage or alternatively the interface between a stock container and the pump device. Advantageously, the arrangement of the passage allows the motor windings to be cooled with the working medium.

[0019] According to one embodiment, the rotor of the electric motor may have a plurality of permanent magnets, adjacent permanent magnets being separated by slits for guiding the working medium.

[0020] According to one embodiment, the slits can be configured to transport the working medium as the rotor rotates, thus allowing circulation of the working medium between the permanent magnets.

[0021] According to one embodiment, the pump can be configured as a bidirectional hydraulic pump, which advantageously allows for an easy output of the working medium depending on the desired conveying direction of the working medium.

[0022] Furthermore, a method for heating a working medium in a pre-heating phase for a steering device in one of the above mentioned variants is presented, which includes the steps of providing a motor signal to an electric motor of the steering device to operate the electric motor, and providing a valve opening signal to a valve of the steering device to open the valve.

[0023] The method can be implemented, for example, in a steering device using one of the control devices of the above mentioned variants. Advantageously, the heat generated during operation of the electric motor can reduce the viscosity of the working medium without exerting a torque on the steering rod of the steering device. The open valve allows the working medium to circulate in the lines of the steering device, whereby the largest possible proportion of the working medium can be heated.

[0024] The method can be implemented, for example, in software or hardware or in a mixed form consisting of software and hardware, for example in a control device, which can be configured to execute, drive or realize the steps of the method variants presented in the present invention in the corresponding device. This variant embodiment of the approach in the form of a device can also quickly and efficiently solve the problem underlying the approach.

[0025] The control device may have at least one calculation unit for processing signals or data, at least one storage unit for storing signals or data, at least one interface to sensors or actuators for reading sensor signals from sensors or outputting data or control signals to actuators, and / or at least one communication interface for reading or outputting data embedded in a communication protocol. The calculation unit may be, for example, a signal processor, a microcontroller or the like, and the storage unit may be a flash memory, an EPROM or a magnetic storage unit. The communication interface may be configured to read or output data wirelessly and / or wired, and a communication interface capable of reading or outputting wired data may read or output these data from or to a corresponding data transmission path, for example electrically or optically.

[0026] In the present invention, a control device can be understood as an electrical device that processes sensor signals and outputs control and / or data signals depending on the sensor signals. The control device can have an interface that can be configured in a hardware and / or software manner. If configured in a hardware manner, the interface can be, for example, part of a so-called system ASIC, which includes several widely different functions of the control device. However, it is also possible that the interface is a specific integrated circuit or is at least partially composed of discrete elements. If configured in a software manner, the interface can be, for example, a software module that is provided in a microcontroller in addition to other software modules.

[0027] The following description, in conjunction with the figures, details several examples of the approach presented in this invention. [Brief description of the drawings]

[0028] [Figure 1] 1 is a schematic diagram of a vehicle equipped with a steering device according to one embodiment. [Diagram 2] 1 is a schematic cross-sectional view of a pump device according to one embodiment; [Diagram 3] 4 is a flow diagram of a method for heating a working medium in a pre-heating phase for a steering device according to one embodiment.

[0029] In the following description of several advantageous embodiments of the present approach, elements that are shown in different figures and that operate in a similar manner will use the same and similar reference numerals to avoid repeated description of these elements.

[0030] 1 shows a schematic diagram of a vehicle 100 with a steering arrangement 102 according to an embodiment. The vehicle 100 is realized, for example, as a commercial vehicle. The steering arrangement 102 is configured to assist the driver of the vehicle 100 in the steering process. The steering arrangement 102 has for this purpose a pump arrangement 104, a transmission arrangement 106, a valve 108 and a control arrangement 110.

[0031] The pump device 104 includes a pump 112 for pumping the working medium to a first outlet port 114 or a second outlet port 116 of the pump device 104. The pump device 104 further includes an electric motor 118 that is configured to drive the pump 112. For this purpose, the electric motor 118 and the pump 112 are connected to each other via a shaft. The pump 112 is realized, for example, as a bidirectional hydraulic pump.

[0032] The transmission 106 has an input shaft 120 connectable to a steering wheel 119 and an output shaft 124 connectable to a pitman arm 122. The transmission 106 further has a transmission element 130 moving in a first direction 126 and a second direction 128 to transmit torque from the input shaft 120 to the output shaft 124. The transmission 106 further includes a first working medium port 132 and a second working medium port 134, the first working medium port 132 being connected to the first outlet port 114 to move the transmission element 130 in the first direction 126 using a working medium, and the second working medium port 134 being connected to the second outlet port 116 to move the transmission element 130 in the second direction 128 using a working medium. To move the transmission element 130 using a working medium, according to one embodiment, at least one cylinder is provided, which is configured to use the pressure of the working medium to move the transmission element 130.

[0033] According to this embodiment, the input shaft 120 is connected or mechanically coupled to the steering wheel 119 of the vehicle 100 via a steering column of the steering system. According to one embodiment, the input shaft 120 is configured to introduce the torque of the steering column of the vehicle 100, which is coupled to the steering wheel 119, to the steering device 102. The torque introduced via the input shaft 120 can also be referred to as input torque. According to this embodiment, the output shaft 124 is configured to direct this torque from the steering device 102 to the outside or to output this torque to the pitman arm 122. The torque directed to the outside via the output shaft 124 can also be referred to as output torque or output force. According to this embodiment, the transmission element 130 is configured to mechanically transfer torque from the input shaft 120 to the output shaft 124 and / or convert the input torque to an output torque. A working medium is used to assist the movement of the transmission element 130 in order to assist the steering movement performed by the driver of the vehicle 100. Correspondingly, the transmission element 130 can only be moved in the automatically steering vehicle 100 by using the pressure of the actuating medium.

[0034] The valve 108 of the steering gear 102 is connected between the first outlet port 114 and the second outlet port 116. According to this embodiment, the first valve port 136 of the valve 108 is fluidly connected to the first outlet port 114 and the first working medium port 132. Similarly, according to this embodiment, the second valve port 138 of the valve 108 is fluidly connected to the second outlet port 116 and the second working medium port 134.

[0035] The steering device 102 further comprises a control device 110, which is configured to determine an actual operating phase of the steering device 102 and to provide, depending on this actual operating phase, suitable motor signals 140 for operating the electric motor 118 and suitable valve signals 142, 144 for controlling the valves 108. According to one embodiment, the control device 110 is configured to initiate a pre-heating phase when heating of the working medium is advantageous, for example to reduce the viscosity of the working medium. The control device 110 may be configured to maintain the pre-heating phase until the working medium is heated to a predetermined temperature. According to one embodiment, following the pre-heating phase, the control device 110 is configured to initiate a normal operating phase, during which a steering assist is provided by the steering device 102, for example for normal driving operation of the vehicle 100. Here, the steering assist can be provided depending on, for example, a request signal indicating a steering requested by a driver of the vehicle 100 and a steering direction 146 of the vehicle 100. According to one embodiment, the controller 110 is configured to provide a motor signal 140 having characteristics that cause rotation of the electric motor 118 associated with one of the steering directions 146 depending on the requested steering direction 146 .

[0036] According to one embodiment, the control device 110 is configured to provide a motor signal 140 and valve signals 142, 144 in the preheating phase to operate, i.e. energize, the electric motor 118, such that, for example, no pressure or only a pressure that is insufficient to move the transmission element 130 is applied to the working medium ports 132, 134, so that no steering assistance is provided. For this purpose, the motor signal 140 is provided, for example, with a characteristic such that a current flows through at least one winding of the electric motor 118, which generates a magnetic field that is not suitable for moving the rotor of the electric motor 118. Alternatively, the motor signal 140 is provided, for example, with a characteristic such that a current flows through at least one winding of the electric motor 118, which generates a magnetic field that is suitable for moving the rotor of the electric motor 118. In this case, the control device 110 is configured to provide a valve signal in the form of a valve opening signal 142 for opening the valve 108. The characteristics of the motor signal 140 may relate to, for example, the amplitude and / or modulation of the motor signal 140 .

[0037] According to one embodiment, the control device 110 is configured to provide a motor signal 140 with a characteristic that ensures proper operation of the electric motor 118 to drive the pump 112 during a normal operating phase. Furthermore, the control device 110 is configured to provide a valve signal to the valve 108 in the form of a valve closing signal 144 for closing the valve 108. This creates a working medium pressure sufficient to assist the steering movement and is applied to one of the working medium ports 132 depending on the conveying direction of the pump device 104.

[0038] Electrical energy provided to the electric motor 118 via the motor signal 140 is partly converted into heat and partly used to drive the rotor of the electric motor 118. According to one embodiment, the control device 110 is configured to provide the motor signal 140 such that the part of the electrical energy provided to the electric motor 118 that is converted into heat is greater in the preheating phase than in the normal operation phase with respect to the part used for driving. According to one embodiment, the control device 110 is configured to provide the motor signal 140 having the following characteristics in the preheating phase: a first amount of current through the motor windings, which generates a first magnetic field, which results in the rotor rotating with a first rotational speed. In contrast, the control device 110 is configured to provide the motor signal 140 having the following characteristics in the normal operation phase: a first amount of current through the motor windings, which generates a second magnetic field, which results in the rotor rotating with a second rotational speed higher than the first rotational speed. This allows

[0039] According to one embodiment, the control device 110 is configured to activate the pre-heating phase in response to a temperature signal 152 indicating a temperature of the working medium below a threshold value. According to this embodiment, the temperature signal 152 is provided by a temperature sensor 154. According to this embodiment, the temperature sensor 154 is realized as part of the pump device 104. Alternatively, the temperature sensor 154 can be arranged in the vehicle 100 in another way. For example, the control device 110 is configured to terminate the pre-heating phase as soon as the temperature signal 152 indicates a temperature of the working medium above a threshold value. Alternatively or additionally, the control device 110 is configured to terminate the pre-heating phase, for example after a predetermined period of time.

[0040] According to this embodiment, the control device 110 is additionally or alternatively configured to activate the pre-heating 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 prime mover control of the vehicle 100.

[0041] According to the embodiment shown above, the pump device 104 has an optional input port 156, via which the pump device 104 is connected to a stock container 158 for pre-stocking the working medium.

[0042] In other words, the possibility of pre-heating the working medium, which can be realized as a hydraulic fluid and can also be called oil, is offered during a cold start of the vehicle 100. This means that for example, for application to the steering of the vehicle 100, for example a truck, an electrohydraulically operated steering transmission, referred to in the present invention as transmission 106, is driven by a hydraulic pump, for example in the form of a pump 112, via a bidirectionally operating pump device 104. The two ports of the pump device 104, referred to in the present invention as a first outlet port 114 and a second outlet port 116, are connected to the transmission 106, for example to at least one cylinder of a typical known steering transmission. According to one embodiment, the electric motor 118 which drives the pump 112 is surrounded by the working medium in a stock container 158, also referred to as a stock tank or auxiliary container. By appropriately driving the electric motor 118, the temperature of the working medium can be raised and thus the viscosity of the working medium can be improved already before the start of the journey.

[0043] According to one embodiment, the electric motor 118 rotates without moving the pitman arm 122 by opening the valve 108, thereby distributing the heated working medium in the pump device 104. The motor windings of the electric motor 118 can be selectively driven so that the motor windings are heated strongly even in a standstill state or when the prime mover power is low.

[0044] In Fig. 2, a schematic cross-sectional view of a pump arrangement 104 according to one embodiment is shown. The pump arrangement 104 shown in this figure may be similar to or correspond to the pump arrangement 104 described in Fig. 1. According to this embodiment, the pump 112 and the electric motor 118 are arranged adjacent to each other in a common casing 200. The casing 200 surrounds the pump 112, the electric motor 118 and a common shaft 201 connecting the pump 112 and the electric motor 118. The working medium conveyed by the pump 112 is guided through the casing 200 so that the working medium is heated by the electric motor 118.

[0045] The electric motor 118 includes a rotor 202 and a stator 203. The rotor 202 has a plurality of permanent magnets, and adjacent permanent magnets are separated by slits 204 for guiding a working medium. The slits 204 are formed to transport the working medium when the rotor 202 rotates.

[0046] According to this embodiment, the casing 200 has a passage 206 for conducting the working medium from an inlet along the inner wall of the casing 200 to a motor winding 208 of the electric motor 118 arranged in a stator 203. This passage 206 is formed to conduct the working medium around the motor winding 208. The flow direction of the working medium is clearly indicated by the depicted arrows 210. According to this embodiment, this also clearly indicates that the motor winding 208 is surrounded by the working medium, for example to allow good thermal coupling.

[0047] In summary, the pump 112 pumps the working medium from the pump outlet 212 through the passages 206 and along the wall of the casing 200 where, according to one embodiment, the working medium is cooled in the direction of the motor windings 208. According to this embodiment, the working medium flows from there, around the motor windings 208, through the slits 204 acting as a circulation pump, in the direction of the casing wall, for example through a heat exchanger 214, to the pump outlet 212.

[0048] In other words, the electric motor 118 is used as a heating device, for example to preheat the working medium when the outside temperature is low. Immersing the motor windings 208 in the working medium allows a good thermal coupling between the electric motor 118 and the surrounding working medium. The slits 204 between the permanent magnets in the rotor 202, also called rotor plate, are used as a drive for circulating the working medium. The working medium circulating in the direction of the arrow 210 flows through the coils of the electric motor 118, which form the motor windings 208, and is heated in the process.

[0049] In Fig. 3, a flow diagram of a method 300 for heating a working medium in a pre-heating phase for a steering device is shown according to one embodiment. The method 300 can be implemented in a control device as described in Fig. 1. The method 300 includes a step 302 of providing a motor signal to an electric motor of the steering device to operate the electric motor, and a step 304 of providing a valve opening signal to a valve of the steering device to open the valve. Steps 302 and 304 are performed in a pre-heating phase which is performed to heat the working medium. According to one embodiment, the valve remains open throughout the duration of the pre-heating phase. According to one embodiment, the electric motor is only operated in the pre-heating phase to heat the working medium, and no steering assist is provided in the pre-heating phase.

[0050] Method 300 optionally includes step 306 of providing a motor signal with the same or modified characteristics associated with step 302, and step 308 of providing a valve closing signal to close the valve. Steps 306 and 308 are performed during a normal operating phase in which pressure is applied to the working medium to steer or assist steering of the vehicle.

[0051] According to one embodiment, the method 300 includes a step 310 of reading a temperature signal indicative of the temperature of the working medium. According to one embodiment, the step 310 is continuously repeated in order to continuously monitor the temperature of the working medium. According to one embodiment, the pre-heating phase continues while the temperature signal indicates a temperature of the working medium below a predetermined operating temperature. For example, after starting the vehicle, it is checked whether the temperature of the working medium already has the operating temperature. If so, the pre-heating phase is skipped and the normal operation phase is directly started. On the other hand, if the temperature of the working medium is below the operating temperature, the pre-heating phase is performed before the start of the normal operation phase in order to raise the temperature of the working medium to the operating temperature. [Explanation of symbols]

[0052] 100 vehicles 102 Steering device 104 Pumping equipment 106 Transmission 108 Valve 110 Control device 112 Pump 114 First discharge port 116 Second discharge port 118 Electric Motor 119 Steering Wheel 120 Input shaft 122 Pitman Arm 124 Output shaft 126 1st direction 128 Second direction 130 Transmission elements 132 First working medium port 134 Second working medium port 136 First valve port 138 Second valve port 140 Motor Signal 142 Valve Open Signal 144 Valve closing signal 146 Steering Direction 148 Steering rod 150 Vehicle Wheels 152 Temperature signal 154 Temperature Sensor 156 input ports 158 Stock Container 160 Starting Signal 200 Casing 201 Axis 202 Rotor 203 Stator 204 Slit Aisle 206 208 Motor Winding 210 Arrow 212 Pump outlet 214 Heat exchanger 300 ways 302 Supplying a motor signal 304 Providing a valve open signal 306 Step of supplying a motor signal 308 Providing a valve closing signal 310 Loading Step

Claims

1. A control device (110) for a vehicle (100) having a steering device (102), the steering device (102) comprising: A pump device (104) including a pump (112) for pumping a working medium to a first discharge port (114) or a second discharge port (116) of the pump device (104) and an electric motor (118) for driving the pump (112); A transmission device (106), The pump (112) and the electric motor (118) have a common shaft and are disposed in a common casing (200); the casing (200) has a passage (206) for directing the working medium from an inlet along an inner wall of the casing (200) to a motor winding (208), the passage (206) being configured to direct the working medium around the motor winding (208); The rotor (202) of the electric motor (118) has a plurality of permanent magnets, and adjacent permanent magnets are separated by slits (204) for guiding the working medium; The transmission device (106) includes an input shaft (120) connectable to a steering wheel (119) and an output shaft (124) connectable to a pitman arm (122), a transmission element (130) moving in a first direction (126) and a second direction (128) to transmit torque from the input shaft (120) to the output shaft (124), and a first working medium port (132) and a second working medium port (134), the first working medium port (132) being connected to the first outlet port (114) for moving the transmission element (130) in the first direction (126) using the working medium, and the second working medium port (134) being connected to the second outlet port (116) for moving the transmission element (130) in the second direction (128) using the working medium, and the control device (110) further includes: a valve (108) connected between the first discharge port (114) and the second discharge port (116); The control device (110) is configured to supply a motor signal (140) to the electric motor (118) of the steering device (102) for operating the electric motor (118) with a lower efficiency than in a normal operation phase during a pre-heating phase for heating the working medium, and to supply a valve opening signal (142) to the valve (108) of the steering device (102) for opening the valve (108), thereby operating the pump device without generating a steering movement.

2. 2. The control device (110) of claim 1, wherein the control device (110) is configured to provide the motor signal (140) to the electric motor (118) for operating the electric motor (118) to move the pitman arm (122) during a normal operating phase and to provide a valve close signal (144) to the valve (108) for closing the valve (108).

3. 3. The control device (110) of claim 2, wherein the control device (110) is configured to provide the motor signal (140) as a signal that causes a current to flow through a motor winding (208) of the electric motor (118) during the preheat phase, the current not resulting in rotation of a rotor (202) of the electric motor (118).

4. 4. The control device (110) of claim 3, wherein the control device (110) is configured to provide the motor signal (140) as a signal that causes a first amount of current to flow through the motor windings (208) during the preheat phase, the current resulting in rotation of the rotor (202) having a first rotational speed, and to provide the motor signal (140) as a signal that causes the first amount of current to flow through the motor windings (208) during the normal operation phase, the current resulting in rotation of the rotor (202) having a second rotational speed higher than the first rotational speed.

5. The control device (110) of any one of claims 1 to 4, wherein the control device (110) activates the pre-heat phase in response to a temperature signal (152) indicative of a temperature below a threshold.

6. The control device (110) of any one of claims 1 to 5, wherein the control device (110) activates the pre-heating phase in response to a start signal (160) indicative of a cold start of the vehicle (100).

7. A steering device (102) for a vehicle (100), said steering device (102) having the following features: A pump device (104) including a pump (112) for pumping a working medium to a first discharge port (114) or a second discharge port (116) of the pump device (104) and an electric motor (118) for driving the pump (112); and The present invention is characterized by a transmission device (106), the transmission device (106) comprising: an input shaft (120) connectable to a steering wheel (119), an output shaft (124) connectable to a pitman arm (122), a transmission element (130) moving in a first direction (126) and a second direction (128) to transmit torque from the input shaft (120) to the output shaft (124), a first working medium port (132) and a second working medium port (134), the first working medium port (132) being connected to the first discharge port (114) for moving the transmission element (130) in the first direction (126) using the working medium, and the second working medium port (134) being connected to the second discharge port (116) for moving the transmission element (130) in the second direction (128) using the working medium; The steering device (102) further includes a valve (108) connected between the first discharge port (114) and the second discharge port (116); and A steering device (102) characterized by a control device (110) according to any one of claims 1 to 6.

8. The steering arrangement (102) of claim 7, wherein a motor winding (208) of the electric motor (118) is surrounded by the working medium.

9. The steering device (102) according to claim 7 or 8, wherein the slits (204) are configured to convey the working medium when the rotor (202) rotates.

10. 10. The steering device (102) according to any one of claims 7 to 9, wherein the pump (112) is configured as a bidirectional hydraulic pump.

11. A method (300) for heating a working medium in a pre-heating phase for a steering device (102) according to any one of claims 7 to 10, said method (300) comprising the steps of: providing a motor signal (140) to an electric motor (118) of the steering device (102) to operate the electric motor (118); and providing a valve open signal (142) to a valve (108) of the steering device (102) to open the valve (108).

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