DE102007000947A1 - Steering device for motor vehicle, has steering column and electromotor for assisted steering force, where steering column and electromotor are arranged together in parallel and coaxial manner - Google Patents

Abstract

The steering device has a steering column (11) and an electromotor (10) for assisted steering force. The steering column and the electromotor are arranged together in parallel and coaxial manner. A gear device (G) is provided with multiple gear elements that are moving in rotating manner for the assisted force of the electromotor on the steering column. A switching shaft (30) is provided for limiting the deflection, which limits multiple rotations of the gear elements.

Description

The Invention relates to a steering device for motor vehicles, with an electric motor for power steering on a Steering column of the motor vehicle according to the Preamble of claim 1.

Especially The invention relates to a steering device, wherein the steering column and the electric motor are arranged parallel or coaxial with each other and the power transmission by means of a transmission device takes place, the at least one belt drive, in particular a toothed belt drive, having.

Such a steering device is for example from the DE 10 2004 059 461 A1 known. There, a power steering is described in which the torque generated by the electric motor is transmitted to the steering column via at least one belt drive. The electric motor is arranged in the vicinity of the steering column in a parallel or coaxial manner, so that a steering force is assisted to the steering column itself. The construction is therefore very space-saving executable.

Also with such a steering device, it is generally necessary to provide a limitation of the deflection. In simple solutions This limitation is achieved by a direct striking of the wheel carrier (Stub axle) on the handlebar. For more comfortable solutions the steering limit or stop limit z. B. in the area the rack. Nevertheless, the known results in practical operation Problem that steering control systems have annoying impact noises can.

As a solution suggests the DE 3429597 A1 a power steering system having stop members attached to the rack to limit the axial movement of the rack against the housing, a portion of the contact surfaces being provided with resilient members so as to initially impinge upon the resilient members; so as to absorb the impact impact before contact between the metals.

Such However, a damping concept is especially for electromotive assisted steering devices are not optimal, because due to the inertia of the electric motor this Damping concept is insufficient to stop the sounds between the pairs of stops, for example track rod and steering gear housing, to dampen.

From the WO 03/029067 A1 a rack and pinion steering device known in which both for conventional and for auxiliary or power assisted steering systems, a stroke limitation is achieved while disturbing casserole noise can be avoided. In this case, a stop means made of elastically yielding material is provided, which is completely bracketed in mutually axially movable, non-elastic parts of the stop means.

however claim the known stop limits relatively much space. However, this makes it difficult, especially in the case of axis-parallel electric motor assisted steering systems reduce the technical effort to create compact designs as possible.

Therefore It is an issue of the present invention to provide a steering device of the type mentioned above with a limitation of the deflection, that overcomes the above problems in an advantageous manner.

These The object is achieved by a steering device solved with the features of claim 1.

Therefore is a steering device for a motor vehicle with a Electric motor for steering power assistance and with a steering column proposed, which are arranged parallel to each other or coaxially, wherein a transmission device is provided, the plurality of rotatable Transmission elements for a transmission of having the electric motor on the steering column, and wherein To limit the deflection, a rotation stop is provided, which is the Number of revolutions of one of the rotatable gear elements limited.

By preferred arrangement of a rotation stop on z. B. one of the drive or output shafts of the transmission device becomes a very effective and structurally compact as well as inexpensive realizable Solution allows.

advantageous Refinements and developments emerge from the dependent claims.

If z. B. the transmission elements comprise elements of a belt drive, so the rotation stop is preferably between a transmission element the belt drive and a fixed part, in particular a with the housing of the electric motor or the steering housing connected part, arranged.

When the gear elements comprise a motor shaft and output shaft of the electric motor and pulleys, wherein the output shaft and the steering column are each provided with one of the pulleys so that the pulley of the output shaft is drivingly connected to the steering wheel pulley by means of a belt, the rotation stopper is preferably at the end input shaft of the electric motor or arranged on one of the pulleys.

If the gear elements elements of an axially parallel belt drive are, the rotation stop is preferably between a transmission element the belt drive and a fixed part, in particular a arranged connected to the housing of the electric motor part.

ever according to requirements, the rotation stop is preferably as a disc stop, designed as a slide stop or as a spur gear stop.

The The invention will now be described in detail with reference to exemplary embodiments and with reference to the accompanying drawings.

1 shows a side view of a first embodiment;

2 shows in more detail a realized in the first embodiment stop limit;

3 shows a side view of a second embodiment;

The 1 shows as the first embodiment of the invention the essential part or region of a steering device, in which an electric motor 10 parallel to a steering column 11 is arranged. The supporting power transmission from the electric motor 10 on the steering column 11 via a transmission device G, the two belt drives with toothed belt 23 and 24 having. Starting from the electric motor 10 is a torque generated there via the first transmission element, namely via an output shaft or rotor shaft 12 initially transferred to a first belt drive. This first belt drive comprises a first pulley 19 on the rotor shaft 12 attached is a second pulley 21 that on another wave 20 attached, and a belt 23 , The belt 23 serves to connect the two pulleys 19 . 21 and may be implemented as a toothed belt, V-belt, multi-ribbed belt (poly-V) or the like. In the illustrated embodiment, the belt 23 designed as a toothed belt.

With the help of the first belt drive thus the generated motor torque is on the other shaft 20 transfer. This shaft in turn has a small pulley 22 that has another toothed belt 24 with a pulley 14 connected, which is on the steering column 11 located. Thus, a two-stage gearbox, which acts in the power transmission or steering assistance is reducing and that of the electric motor 10 Torque generated reliably on the steering column 11 transmits. Depending on the direction of rotation and speed of the output shaft or motor shaft 12 then acts a servo force, which is the rotation of the steering column 11 supported.

To limit the deflection is according to the invention in at least one of the rotatable transmission elements in the transmission device 12 . 14 . 19 . 20 . 21 . 22 . 23 , and or 24 a rotation stop 30 provided here z. B. on the motor shaft 12 is mounted, and thus the number of revolutions of the motor shaft 12 defined limited.

As based on the 2 still clearly he can be seen in the first embodiment shown, the rotation stop 30 designed as a disc stop, in which several loose discs 32 or disc segments on the motor shaft 12 Rotor shaft are arranged adjacent to each other, wherein each disc has a nose, so that after each a certain angle of rotation, a disc takes the next with, until the last disc by a stop pin 31 is prevented from further rotation. Thus, a precisely vorgebare number of revolutions can be met. The use of a rotation stop 30 represents a very accurate and compact feasible solution and z. B. also be designed as a mother stop, slide stop Stirnradanschlag.

Through here in the 1 and 2 shown arrangement with a multi-stage belt transmission can be dispensed with a relatively expensive and space-consuming worm gear or the like. In addition, belt transmissions have a lower efficiency compared to worm gears. The use of belts thus saves costs and installation space. In addition, the use of timing belt enables a secure torque transmission, the timing belt work normally over the entire vehicle life without play and noise. Alternatively to the here in 1 and 2 In the embodiment shown, it is also possible to use a transmission in which the toothed belt is toothed on both sides and the two sides of the toothed belt have a different number of teeth, so that an extremely high reduction ratio can be realized.

When using the 1 and 2 described embodiment, the motor shaft 12 and the steering column 11 as well as the further wave 20 arranged parallel to each other. The further wave 20 is used in the transmission device as an intermediate shaft on which the pulleys 21 and pulley 22 are mounted in order to achieve the highest possible reduction ratio and to realize a two-stage belt transmission, wherein the diameter of the pulleys 19 . 21 . 22 and 14 are chosen so that as possible a large reduction of the rotation number of the electric motor 10 is reached. Of course, besides the wave 20 Even more waves are provided to build higher-level belt transmissions, and thereby even larger ratios of the speed of the electric motor 10 to reach.

The 3 now shows as a second embodiment a coaxial arrangement comprising a hollow motor shaft 51 having. In the hollow motor shaft 51 is a steering column 52 introduced, which is why this embodiment requires very little space. Parallel to the motor shaft 51 and to the steering column 52 is another wave 53 arranged on the one big pulley 56 and a small pulley 57 is arranged, with the large pulley 56 with a smaller pulley 54 on the motor shaft 51 and the small pulley 57 with a larger pulley 55 on the steering column 52 connected is.

Due to the selected arrangement of the pulleys 54 . 55 . 56 and 57 Also, a high reduction ratio can be achieved.

The pulleys 55 and 57 are on the waves 52 and 53 to the right of the pulleys 56 and 58 arranged. By this arrangement, a torque sensor not shown here in the steering column 52 in the area of the electric motor 50 to get integrated. The torque sensor may then detect the torque required for steering to allow the electric motor 50 depending on the determined torque can produce the required power steering. Conveniently, the steering column 52 stored in a steering column housing.

The Solution according to the invention can in all ways be applied by steering, such. B. on rack-and-pinion steering or steering having a ball screw thread. Also suitable the solution according to the invention for for steer-by-wire steering, which has a second electric motor and a second transmission device.

10

electric motor

11

steering column

G

Transmission device (between electric motor 10 and steering column 11 )

12

Motor shaft or output shaft of the electric motor 10

20

Further Shaft (intermediate shaft)

19 21 22, 14

pulleys

23 24

toothed belt

30

Rotation stop (designed as a disc stop) on the motor shaft 12

31

Housing part (of the electric motor 10 ) with stop pin

32

loose Slices with stop noses

50

electric motor (in the second embodiment)

51

Motor shaft or output shaft of the electric motor 50 (designed as a hollow shaft)

52

steering column

53

Further wave

54 55, 56, 57

pulleys

58 59

toothed belt

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 102004059461 A1 [0003]
• - DE 3429597 A1 [0005]
• WO 03/029067 A1 [0007]

Claims (9)

Steering device for a motor vehicle with a steering column ( 11 ) and with an electric motor ( 10 ) to the power steering, wherein the steering column ( 11 ) and the electric motor ( 10 ) are arranged parallel or coaxial with each other and a transmission device (G) is provided, the plurality of rotatable gear elements ( 12 . 20 ) for a power transmission from the electric motor ( 2 ) on the steering column ( 11 ), characterized in that to limit the deflection, a rotation stop ( 30 ) is provided, which determines the number of revolutions of one of the rotatable transmission elements ( 12 . 20 ) limited. Steering device according to claim 1, characterized in that the transmission elements ( 12 . 20 ) Elements of an axis-parallel belt drive ( 12 . 14 . 19 . 20 . 21 . 22 . 23 . 24 ), wherein the rotation stop ( 30 ) between a transmission element ( 12 ) of the belt drive and a fixed part, in particular one with the housing of the electric motor ( 10 ) or the steering device connected part ( 31 ) is arranged. Steering device according to claim 1 or 2, characterized in that the transmission elements an output shaft ( 12 ) of the electric motor ( 10 ) and pulleys ( 19 . 21 . 22 . 14 ), wherein the output shaft ( 12 ) and the steering column ( 11 ) each with one of the pulleys ( 19 . 14 ), so that the pulley ( 19 ) of the output shaft ( 12 ) with the pulley ( 14 ) of the steering column ( 11 ) by means of at least one belt ( 23 . 24 ) is drivingly connected, wherein the rotation stop ( 30 ) on the output shaft ( 12 ) of the electric motor ( 10 ) or on one of the pulleys ( 19 . 21 . 22 . 14 ) is arranged. Steering device according to claim 1 or 2, characterized in that the gear elements form a further shaft ( 20 ), which are for a power transmission from the electric motor ( 10 ) on the steering column ( 11 ) via one of the belts ( 23 . 24 ) with the output shaft ( 12 ) of the electric motor ( 10 ) or the steering column ( 11 ), wherein the rotation stop on the further shaft ( 20 ) or on the steering column ( 11 ) is arranged. Steering device according to claim 1 or 2, characterized in that the gear elements a hollow output shaft ( 51 ) of the electric motor ( 50 ), in which the steering column ( 52 ), and pulleys ( 54 . 55 . 56 . 57 ), wherein the output shaft ( 51 ) and the steering column ( 11 ) each with one of the pulleys ( 54 ; 55 ), so that the pulley ( 54 ) of the output shaft ( 51 ) with the pulley ( 55 ) of the steering column ( 51 ) by means of at least one belt ( 58 . 59 ) is drivingly connected, wherein the rotation stop ( 30 ) on the hollow output shaft ( 51 ) of the electric motor ( 50 ) or on one of the pulleys ( 54 . 55 . 56 . 57 ) is arranged. Steering device according to one of the preceding claims, characterized in that the rotation stop as a mother stop is executed. Steering device according to one of the preceding claims, characterized in that the rotation stop as a disc stop ( 30 ) is executed. Steering device according to one of the preceding claims, characterized in that the rotation stop as a slide stop is executed. Steering device according to one of the preceding claims, characterized in that the rotation stop as Stirnradanschlag is executed.