RACK STEERING SYSTEM AND MOTOR VEHICLE HAVING SUCH A RACK STEERING SYSTEM

Abstract

A rack steering system and a motor vehicle having such a rack steering system. The inventive rack steering system comprises a steering gear housing, a toothed rack, which extends through the steering gear housing, an electric motor, which is coupled to the toothed rack on a thread side of the steering gear housing via a ball screw to provide an axial force to the toothed rack, and two track rod links arranged at axial ends of the toothed rack. The steering gear housing is designed in one piece such that a drive insert opening is formed on the thread side of the steering gear housing for arrangement of the electric motor and a direct stop face for a track rod link or a support face for the arrangement and axial support of a separate stop element for a track rod link is also formed on this thread side.

Claims

1. A rack steering system comprising: a steering gear housing; a toothed rack that extends through the steering gear housing; an electric motor coupled to the toothed rack on a thread side of the steering gear housing via a ball screw in order to provide an axial force at the toothed rack; and two track rod links arranged at the axial ends of the toothed rack, wherein the steering gear housing is designed in one piece such that a drive insert opening for arrangement of the electric motor is formed on the thread side of the steering gear housing and a direct stop face for a track rod link or a support face is also formed on this thread side for the arrangement and axial support of a separate stop element for a track rod link.

2. The rack steering system according to claim 1, wherein on the thread side of the housing is a mounting arm that extends in a radial and/or axial direction, or are multiple mounting arms, which extend in the radial and/or axial direction.

3. The rack steering system according to claim 2, wherein at least one screw opening is formed on each mounting arm.

4. The rack steering system according to claim 1, wherein the drive insert opening is closed via a plastic cover.

5. The rack steering system according to claim 1, wherein the drive insert opening is closed via a cuff.

6. The rack steering system according to claim 1, wherein a support face is formed, which extends only over a part of the circumference of a circular ring, and wherein a drive belt, which is functionally arranged between electric motor and ball screw, extends through the area in which there is no support face.

7. The rack steering system according to claim 1, wherein at least one support rib is provided, via which the surface of the support face is enlarged.

8. The rack steering system according to claim 1, wherein at least one circular ring-shaped disc is provided as a separate stop element.

9. The rack steering system according to claim 1, wherein a separate stop element has structures for stiffening and/or is conically formed.

10. The rack steering system according to claim 1, wherein a separate stop element is firmly connected to the steering gear housing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

[0020] FIG. 1 is a sectional view of a schematic representation of a steering gear housing of the invention with further elements arranged therein,

[0021] FIG. 2 is a representation of an inventive steering gear housing without further elements in an isometric representation,

[0022] FIG. 3 is a representation of the steering gear housing from FIG. 2 in a view according to the arrow III in FIG. 2,

[0023] FIG. 4 is a representation of the steering gear housing from FIGS. 2 and 3 in a view according to the arrow IV in FIG. 2,

[0024] FIG. 5 is an exploded view of a representation of the steering gear housing from FIGS. 2 to 4 with a stop disc, a cover, a track rod link, and mounting screws,

[0025] FIG. 6 is a sectional view of a detail of the steering gear housing from FIGS. 2 to 5 with the track rod link, stop disc and a mounting screw in the mounting position,

[0026] FIG. 7 is another example design of a stop disc with stiffeners,

[0027] FIG. 8 is another example design of a stop disc with stiffeners,

[0028] FIG. 9 is another example design of a stop disc with a two-sided conical geometry, and

[0029] FIG. 10 is another example design of a stop disc with a one-sided conical geometry.

DETAILED DESCRIPTION

[0030] FIG. 1 shows a schematic representation of a rack steering system 10 with an inventive steering gear housing 12, a toothed rack 14, which extends through the steering gear housing 12, and an electric motor 16, which is coupled to the toothed rack 14 on a thread side 18 of the steering gear housing 12 via a ball screw 20. In the embodiment shown, the link between the electric motor 16 and the ball screw 20 is established via a motor shaft 22 and a belt drive 24 transmitting the drive torque of the electric motor 16. Alternatively, the functional connection between electric motor 16 and ball screw 20 can also be made with other suitable transmission elements.

[0031] For the sake of completeness, it is also pointed out that in the shown embodiment the toothed rack 14 has a toothing on the side opposite the thread side 18 on which a pinion 28 arranged at the lower end of a steering shaft 26 engages. By turning a not-shown steering wheel, which is coupled to the steering shaft 26, it is possible for the driver of a not-shown motor vehicle to manually apply a steering torque. If necessary, this steering torque can be supported by a steering auxiliary torque of the electric motor 16 by supporting a displacement of the toothed rack 14 via the ball screw 20.

[0032] Only schematically shown in FIG. 1 are a first mounting arm 36 extending in the axial direction and the radial direction, and a second mounting arm 38 extending predominantly in the radial direction. Furthermore, a third mounting arm 46 and a fourth mounting arm 48 are formed on the steering gear housing 12 on the side opposite the thread side, both of which have an opening 50, 52 each.

[0033] FIGS. 2 to 6 show different views of a slightly deviating embodiment of a steering gear housing 12 according to the invention. The steering gear housing 12 is also designed in one piece in such a way that a drive insert opening 44 is formed on the thread side 18 for inserting the electric motor. A support face 30 for the arrangement and axial support of a separate stop element 32 for a track rod link 34 is also formed on the thread side 18.

[0034] As can be clearly seen in FIGS. 2 to 6, a first mounting arm 36 extending in the axial direction and a second mounting arm 38 extending in the axial direction are further formed on the steering gear housing 12 on the thread side 18. In the embodiment shown, the two mounting arms 36, 38 both have an opening 40, 42 each and thus allow for simple screwing of the mounting arms 36, 38 to a body-fixed element, in particular to a not-shown subframe of a motor vehicle.

[0035] As can be seen in FIG. 2, a third mounting arm 46 and a fourth mounting arm 48 are formed on the steering gear housing 12 on the side opposite the thread side 18, both of which also have an opening 50, 52 each. The third mounting arm 46 and the fourth mounting arm 48 each extend predominantly in the radial direction and slightly in the axial direction.

[0036] As can be clearly seen in FIG. 6, the stop element 32 is firmly connected to the steering gear housing 12 in the final assembly position, e.g., by caulking, pressing, soldering, welding and/or gluing. The drive insert opening 18 is closed by means of a cover 54, which is preferably made inexpensively of plastic. In the embodiment shown, the cover is screwed with four mounting screws 56.

[0037] In FIGS. 5 and 6, a simple circular ring-shaped disc is provided as a stop element 32.

[0038] Here it can also be seen in FIG. 6 that in the steering gear housing 12, a support rib 64 extending in the axial direction is formed in such a way that an additional support face 30 is provided, specifically a suitable circular ring-shaped design of the steering gear housing 12 with a shoulder serving as a support face 30 and the left-facing end face of the support rib 64 serving as a further support face 30, so that the overall result is a larger support face 30.

[0039] FIGS. 7 to 10 show further variants for usable, alternative stop elements 32, which are also designed as circular ring-shaped discs.

[0040] The stop element 32 according to FIG. 7 has six stiffeners 58 in the form of stamped embossments 60.

[0041] The stop element 32 according to FIG. 8 has six stiffeners 58 in the form of ribs 62, which can be produced in particular by molding.

[0042] The stop element 32 according to FIG. 9 is designed to be conical on two sides.

[0043] The stop element 32 according to FIG. 10 is designed to be conical on one side as a spring disc.

[0044] The features of the invention disclosed in the present description, drawings and claims may be essential, both individually and in any combination, for the implementation of the invention in its various embodiments. The invention can be varied within the scope of the claims and taking into account the knowledge of the competent skilled person.

[0045] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.