BE1031995B1 - Drive system and motor vehicle - Google Patents

Abstract

Drive device (10) for a manual torque adjuster of a steer-by-wire steering system or an electromechanical steering system for a motor vehicle, at least comprising - an electric motor (11) with a stator housing in which a rotor with a rotor shaft is rotatably mounted, - a gear (12) for coupling the rotor shaft to a steering shaft (13) of the motor vehicle, and - a control unit (14) which is connected to the electric motor (11) by a connecting unit (15) for controlling the electric motor (11), wherein the gear (12) is arranged between the electric motor (11) and the control unit (14), and the connecting unit (15) for connecting the electric motor (11) to the control unit (14) at least partially bridges the gear (12).

Description

Drive device and motor vehicle

The invention relates to a drive device for a manual torque controller of a steer-by-

Wire steering system or an electromechanical steering system for a motor vehicle and a

Motor vehicle. A drive device according to the preamble of patent claim 1 is known, for example, from DE 10 2020 202 340 A1.

Steer-by-wire steering systems for motor vehicles accept manual steering commands from the driver as usual by turning a steering wheel. The steering wheel causes the rotation of a

Steering shaft, which is not mechanically but electrically connected to the wheels of the

The wheels to be steered are controlled by steering signals. The steering command is recorded via angle and/or torque sensors. A corresponding electrical control signal is transmitted to a steering actuator, which

Adjusts the steering angle of the wheels.

With steer-by-wire systems, the driver does not receive any direct mechanical feedback from the steered wheels via the steering line, which in conventional mechanically coupled steering systems is provided as a reaction or restoring torque depending on the

Road surface conditions, vehicle speed, current steering angle and/or other parameters are fed back to the steering wheel. The lack of haptic feedback makes it difficult for the driver to reliably grasp current driving situations and to take appropriate

To carry out steering maneuvers, which reduces the vehicle's steerability and thus driving safety.

To create a realistic driving experience, it is known from the state of the art to derive parameters such as vehicle speed,

Steering angle, steering reaction torque and/or other parameters are measured or calculated in a simulation. Using these parameters, a feedback signal is generated, which is fed into a manual torque controller, also called a feedback actuator or handwheel actuator. The manual torque controller brings

The feedback signal injects a restoring torque (feedback torque) into the steering shaft that corresponds to the actual reaction torque. Such systems, also called "force feedback" systems, give the driver the impression of a real driving situation, similar to a conventional steering system, which facilitates intuitive response.

A drive device for a manual torque controller is known, for example, from DE 10 2020 202 340 A1, which is attributed to the applicant. Even if the known

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drive system already works very well, there is room for improvement with regard to the

Arrangement of the drive system components, since the existing arrangement requires a lot of space. Other steering systems with a drive system for a

Feedback actuators are known, for example, from the publications DE 10 2021 214 426 A1,

DE 10 2021 201 229 A1 and WO 2021/089180 A1.

The invention is therefore based on the object of solving the problem arising from the state of the art mentioned at the outset.

The invention further aims to improve a drive device known in the art by reducing the installation space required. The invention is also based on the object of providing a motor vehicle with such a drive device for a manual torque controller.

According to the invention, this object is achieved by the subject matter of claim 1. With regard to the motor vehicle, this object is achieved by the subject matter of claim 5.

Specifically, the task is carried out by a drive device for a manual torque controller of a

Steer-by-wire steering system or an electromechanical steering system for a motor vehicle, which comprises at least the following: - an electric motor with a stator housing in which a rotor with a rotor shaft is rotatably mounted, - a gear, in particular a worm gear, for coupling the rotor shaft to a

Steering shaft of the motor vehicle, and - a control unit which is connected to the electric motor by a connecting unit for controlling the electric motor.

The gearbox is located between the electric motor and the control unit and the

Connection unit bridges the gearbox to connect the electric motor with the

Control unit at least partially.

The invention has the advantage that the installation space requirement of the drive device is reduced by arranging the electric motor and the control unit on different sides of the transmission. The transmission is thus arranged between the electric motor and the control unit. The steering shaft of the motor vehicle, on which the transmission is arranged, can be arranged between the electric motor and the control unit. This is to be understood in such a way that the electric motor and the control unit are arranged at a distance from one another.

The gearbox is located in the space between the electric motor and the control unit.

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This distance or gap is bridged by the connecting unit in order to connect the control unit for controlling the electric motor to it.

This ensures secure communication between the electric motor and the control unit. The control unit can provide the required steering assistance, which the

Electric motor has to be introduced into the steering system to relieve the driver, and passed on to the electric motor via the connection unit.

Furthermore, it is advantageous that the components of the drive device, in particular the

The control unit and the electric motor are arranged evenly around the gearbox. This reduces or eliminates the installation space required, particularly on one side of the gearbox. Furthermore, this even arrangement of the electric motor and the

The control unit around the transmission avoids an overhang on one side of the transmission. Consequently, the center of gravity of the drive mechanism is advantageously located in the area of the transmission. In other words, the center of gravity can be centrally located relative to the drive mechanism or on the steering shaft. In other words, the center of gravity of the entire arrangement is advantageously located between the electric motor and the control unit.

This makes it possible to achieve an even weight distribution of the drive system.

Furthermore, the drive device can advantageously be used for a manual torque controller, in particular an electric manual torque controller, a steer-by-wire steering system or an electromechanical steering system. In other words, the

Drive device applicable for various steering systems.

In a steer-by-wire steering system, the steered wheels and the steering wheel are not mechanically coupled, but electrically. The steered wheels are controlled by steering signals. The respective steering wheel position is detected by a steering angle sensor. The corresponding steering signal causes a steering actuator to change the position of the steered wheels.

In the case of a steer-by-wire steering system, the drive device according to the invention can be

steering shaft.

In an electromechanical steering system (Electric Power Steering; EPS for short), a program-controlled electric motor on the steering mechanism supports the steering movements of the

Driver. A distinction is made between different designs, which differ, among other things, in the positioning of the electric motor and/or the control unit in the steering system. The electric motor and/or the control unit can be mounted either on the

Steering shaft (Column-EPS), on the steering gear pinion (Pinion-EPS) or around the rack (Rack-

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EPS). The drive device according to the invention can advantageously be used for all of the aforementioned variants of the electromechanical steering system.

Preferred embodiments of the invention are specified in the subclaims.

According to the invention, the electric motor and the control unit are arranged opposite one another with respect to the transmission, in particular along an axis. In other words, the electric motor and the control unit can be arranged on opposite sides of the transmission. Due to the opposite arrangement of the electric motor and the

The control unit can be used to save installation space and avoid overhangs on one side. It is possible, but not absolutely necessary, that the control unit is mounted along a

The rotor axis of the electric motor is arranged or aligned. The rotor axis can run transversely to a longitudinal axis of the steering shaft. Alternatively, it is possible that the

The control unit and the electric motor are arranged along an axis parallel to the

rotor axis.

According to the invention, the connecting unit connects the electric motor and the control unit in such a way that the connecting unit carries the control unit. For this purpose, the

The connecting unit can be attached to the electric motor and the control unit. In other words, the connecting unit can connect the electric motor and the control unit both electrically and mechanically. Furthermore, the control unit can be connected to the connecting unit and other

Components of the vehicle, such as the vehicle body. It is possible that the control unit is connected to the gearbox or to a housing of the

gearbox. Alternatively, the control unit can be operated exclusively by the

connection unit.

Furthermore, at least one torque sensor is advantageously arranged on the steering shaft to detect the torque applied to the steering shaft during operation. This is preferably to be understood in such a way that the torque sensor detects the torque that the driver applies to the

steering wheel or the steering shaft. Based on this data, the

The control unit calculates the steering assistance that the electric motor must provide to the steering system to relieve the driver's workload. This reduces the force required to operate the steering wheel and increases driving comfort. The torque sensor is preferably located at the transmission input. Other arrangements for the torque sensor are possible.

Preferably, at least one rotor position sensor is provided for detecting the angular position of the

The rotor shaft of the electric motor is located on the control unit. The advantage here is that the

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Rotor position sensor enables precise determination of the rotor position. Furthermore, the

Rotor position sensor provides highly dynamic control of the electric motor.

The rotor position sensor is preferably designed as a digital sensor that generates a robust signal. This is particularly advantageous if the rotor position sensor is located at a distance from the

Electric motor, i.e. not directly on the rotor shaft of the electric motor. For example, the rotor position sensor can be located on the control unit or on the

control unit. Alternatively, the rotor position sensor can be mounted on the

electric motor or on the rotor shaft. In this case, the

Rotor position sensor must be designed as an analog sensor.

Further preferably, a coupling for the torque-locking connection between the

The coupling can be designed as a claw coupling or as a torsionally rigid coupling, which has a high torsional stiffness. This means that the coupling is subject to little deformation under torsional stress. Alternatively, a direct connection between the gearbox and the electric motor can be used in the form of a direct

shaft, i.e. without a coupling.

According to the independent claim 5, the invention relates to a motor vehicle with a drive device according to the invention for a manual torque adjuster.

The invention is explained in more detail below using an embodiment with reference to the attached schematic figure.

This shows

Fig. 1 is a schematic representation of a drive device for a manual torque adjuster according to a preferred embodiment of the invention.

Fig. 1 shows a drive device 10 for a manual torque controller according to a preferred embodiment of the invention. This is the application of the

Drive device 10 for a manual torque controller of a steer-by-wire steering system.

Alternatively, the drive device 10 can also be used for a manual torque controller of an electromechanical steering system, in particular a column EPS system.

In Fig. 1 it can be seen that the drive device 10 comprises an electric motor 11. The electric motor 11 has a stator housing in which a rotor with a rotor shaft is rotatably mounted

6 BE2023/5778. A stator or phase winding can be mounted in the stator housing. Generally, different motor variants are possible. Preferably, the electric motor 11 is a

Synchronous machine.

From Fig. 1 it can also be seen that the drive device 10 has a gear 12 for coupling the

Rotor shaft with a steering shaft 13 of the motor vehicle. The output wheel of the

Gearbox 12 is connected to the steering shaft 13 in a rotationally fixed manner. Specifically, the gearbox 12 is

Worm gearing is used, with the worm wheel being non-rotatably connected to the steering shaft 13 and the worm shaft being coaxially aligned with the rotor shaft of the electric motor 11. Other types of gearing are possible.

In the case of an electromechanical steering system (not shown in Fig. 1), the

The drive device 10 has a shaft section on the side facing away from the steering wheel 19, which is torque-lockingly coupled to the transmission 12. Such a shaft section can be coupled to an intermediate steering shaft, which transmits the torque input by the electric motor 10 to a steering gear for steering the wheels.

The steering shaft 13 is preferably mounted in a casing unit (not shown) of a steering column, which, with the interposition of a support unit, is connected to a vehicle-fixed structure of the

motor vehicle.

Furthermore, Fig. 1 shows that the steering shaft 13 has a steering wheel 19 at its rear end with respect to the direction of travel, whereby a driver can introduce a torque into the steering shaft 13.

As shown in Fig. 1, the electrical control of the electric motor 11 is carried out by an electrical control unit 14. The control unit 14 has a control board, also

Printed circuit board (PCB) with various interconnected electrical components. Furthermore, the control board is located in a

Control housing. Different designs of the control unit 14 are possible.

Furthermore, it can be seen in Fig. 1 that the control unit 14 for controlling the electric motor 11 is connected to the electric motor 11 by a connecting unit 15. The

Connection unit 15 can be designed as a frame which provides a cable routing from

Electric motor 11 to the control unit 14.

Furthermore, Fig. 1 shows that the transmission 12 is arranged between the electric motor 11 and the control unit 14. Specifically, the transmission 12 is arranged in a space

/ BE2023/5778 between the electric motor 11 and the control unit 14. Consequently, the

Electric motor 11 and the control unit 14 are arranged at a distance from each other. This is preferably to be understood in such a way that the electric motor 11 is arranged on one side of the transmission 12 and the control unit 14 on the other side of the transmission 12. It can be seen that the components of the drive device 10, i.e. the electric motor 11, the

Control unit 14 and the gearbox 12 are arranged evenly around the steering shaft 13.

From Fig. 1 it can be seen that the connecting unit 15 connects the gear 12 to the

Connection of the electric motor 11 with the control unit 14 is bridged. In this embodiment, the connection unit 15 extends from the control unit 14 via the

Gearbox 12 to the electric motor 11. The connecting unit 15 establishes an electrical and mechanical connection between the electric motor 11 and the control unit 14.

Fig. 1 shows that the electric motor 11 and the control unit 14 are arranged opposite each other with respect to the transmission 12. Specifically, the electric motor 11 and the

Control unit 14 arranged along a common axis, which is preferably transverse to

Steering shaft 13 is aligned.

Furthermore, Fig. 1 shows that the connecting unit 15 connects the electric motor 11 and the

Control unit 14 in such a way that the connecting unit 15

Control unit 14. In other words, the connecting unit 15 is designed as a supporting structure that provides stability to the arrangement of the components of the drive device 10.

As can be seen in Fig. 1, a torque sensor 16 is provided for detecting the torque applied to the

Steering shaft 13 applied torque is arranged on the steering shaft 13. Specifically, the

Torque sensor 16 located at the gearbox input.

Furthermore, Fig. 1 shows that a rotor position sensor 17 for detecting the

Angular position of the rotor shaft of the electric motor 11 is arranged on the control unit 14.

Specifically, the rotor position sensor 17 is designed as a digital sensor. Alternatively, the

Rotor position sensor 17 can be designed as an analog sensor. The sensor type can be adapted to the position of the sensor. The rotor position sensor 17 can also be referred to as a rotation angle sensor, which can preferably comprise a vernier arrangement.

Fig. 1 further shows that a clutch 18 for the torque-locking connection between the

Gearbox 12 and electric motor 11. Specifically, on the rotor shaft of the

A clutch 18 is arranged on the transmission side of the electric motor 11. The clutch 18 can be used as

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Claw coupling. Other variants of coupling 18 are possible.

For example, the coupling 18 can be designed as a torsionally rigid coupling with a high torsional stiffness. Alternatively, the torsional load on the coupling 18 can be

Load estimation can be reduced.

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List of reference symbols 10 Drive device 11 Electric motor 12 Gearbox 13 Steering shaft 14 Control unit

Connection unit 16 Torque sensor 0 17 Rotor position sensor 18 Clutch 19 Steering wheel

Claims (5)

Claims 1. Drive device (10) for a manual torque controller of a steer-by-wire steering system or an electromechanical steering system for a motor vehicle, at least comprising - an electric motor (11) with a stator housing in which a rotor with a rotor shaft is rotatably mounted, - a gear (12) for coupling the rotor shaft to a steering shaft (13) of the motor vehicle, and - a control unit (14) which is connected to the electric motor (11) by a connecting unit (15) for controlling the electric motor (11), characterized in that the gear (12) is arranged on the steering shaft (13) between the electric motor (11) and the control unit (14), and the connecting unit (15) for connecting the electric motor (11) to the control unit (14) at least partially bridges the gear (12), wherein the electric motor (11) and the control unit (14) are arranged opposite one another with respect to the gear (12), and wherein the connecting unit (15) connects the electric motor (11) and the control unit (14) in such a way that the connecting unit (15) carries the control unit (14). 2. Drive device (10) according to claim 1, characterized in that at least one torque sensor (16) is arranged on the steering shaft (13) for detecting the torque applied to the steering shaft (13) during operation. 3. Drive device (10) according to one of the preceding claims, characterized in that at least one rotor position sensor (17) for detecting the angular position of the rotor shaft of the electric motor (11) is arranged on the control unit (14). 4. Drive device (10) according to one of the preceding claims, characterized in that a clutch (18) is arranged for the torque-locking connection between the transmission (12) and the electric motor (11). 5. Motor vehicle with a drive device (10) for an electric power steering system according to one of the preceding claims.