Machine element or mechanism – Control lever and linkage systems – Hand operated
Patent
1995-07-27
1997-04-01
Marmor, Charles A.
Machine element or mechanism
Control lever and linkage systems
Hand operated
74422, B62D 312, F16B 2118
Patent
active
056155824
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a rack-and-pinion steering gear, in particular for motor vehicles.
In such steering gears, the steering shaft bears a driving pinion that engages a rack which is arranged laterally with respect to the steering shaft and which is movable axially. To support the rack and to press into the driving pinion, there is provided a thrust piece that is retained in a housing borehole and that rests against the back of the rack by virtue of spring force. The thrust piece is supported via a stop in the housing. As stop, there is provided a snap ring, anchored in a housing borehole, and a supporting part, retained against said ring.
2. Description of the Prior Art
In a steering gear known from EP A 0 124 418, a disc lies as supporting part on the snap ring and, supported against the disc, there is a spring that keeps the thrust piece resting against the rack without clattering. This kind of thrust piece support has a very simple structure but, to adjust the play, one must measure both the thickness of the snap ring and the thickness of the disc. In addition, there is the fact that the disc must be mounted and must be held during the assembly of the snap ring.
The object of the invention is to find a reasonably priced and elastically yielding thrust piece support that will require less parts and that will use parts that are simple to install. Such a design should be suitable particularly for the large-series production of rack-and-pinion steering gears to be used in smaller passenger cars.
SUMMARY OF THE INVENTION
The support of the thrust piece according to the invention has, as a supporting part, at least one bar that is firmly connected with the snap ring and that is aimed toward the center of the thrust piece. This bar replaces the disc that is now present in the state of the art. If one makes the bar sufficiently stiff, then a spring element--for pressing the thrust piece on--can be supported on the bar. In this case, one therefore needs only two parts for the thrust piece support: the snap ring and one spring. One can also make the bar--which is connected to the snap ring--elastically. The bar then directly supports the thrust piece and at the same time acts as a spring element. One thus needs only a single part for the thrust piece support. The snap ring is anchored in a groove of the thrust piece housing borehole. The play of the thrust piece can be adjusted easily by means of the selective assembly of snap rings having different thicknesses.
In one particular embodiment, a circular plate is molded as bar in the center of the snap ring; said bar is connected to the snap ring by a constriction. The bar lies in the same plane as the snap ring a serves as supporting plate either for the spring element or for the thrust piece. The bearing is simpler and the production costs are lower because one only needs one part when the thrust piece is supported directly.
The supporting part can also be made with bars that extend in star fashion toward the snap ring and that rest on projections of the snap ring. One of the bars is attached to one projection. This design is suitable for supporting the thrust piece by means of a spring element.
According to another embodiment, one can provide on the snap ring equally spaced and inward-protruding bars on which the spring element rests. The snap rings with the inside-located spring supports can be made cheaply by means of precision stamping and subsequent hardening.
Finally, the invention also comprises another embodiment with a spring element integrated into the snap ring. For this purpose, there is provided a bar that is molded upon the snap ring and that extends into the center of the snap ring. Depending on the required spring stiffness, the bar can be made with lesser thickness than the snap ring or with the same thickness as the snap ring. The bar rests on a nose of the thrust piece and presses said piece into the rack. One can therefore eliminate a separate spring element.
The invention is desc
REFERENCES:
patent: 1988345 (1935-01-01), Vaughn
patent: 2236206 (1941-03-01), Becker
patent: 3325755 (1967-06-01), Peek et al.
patent: 3777589 (1973-12-01), Adams
patent: 4215591 (1980-08-01), Bishop
patent: 4619155 (1986-10-01), Futaba
patent: 4680981 (1987-07-01), Downing
patent: 4815329 (1989-03-01), Ansgar et al.
Grabow Troy
Marmor Charles A.
ZF Friedrichshafen AG
LandOfFree
Rack-and-pinion steering gear, in particular for motor vehicles does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Rack-and-pinion steering gear, in particular for motor vehicles, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Rack-and-pinion steering gear, in particular for motor vehicles will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-531615