Suspension strut bearing

Details Suspension strut bearing Suspension strut bearing

1998-06-26

2001-07-10

Olszewski, Robert P. (Department: 2167)

Land vehicles

Wheeled

Running gear

C280S124155, C267S220000, C267S221000

Reexamination Certificate

active

06257605

ABSTRACT:

FIELD OF THE INVENTION
The invention concerns a suspension strut for the suspension of wheels of an automotive vehicle. The suspension strut preferably used for front wheels comprises a shock absorber and a coil spring arranged coaxially around the shock absorber, the suspension strut being connected to a steering knuckle and a vehicle body at articulation points. A bearing, particularly a thrust ball bearing or an angular contact thrust ball bearing is arranged between the suspension strut and the vehicle body and is mounted sealed while being surrounded by annular carrier elements.
BACKGROUND OF THE INVENTION
In present day vehicles, so-called McPherson suspension struts are in common use. They generally comprise two relatively rotatable elements provided with a bearing arranged therebetween to facilitate rotation while at the same time permitting load transmission between the elements. The two relatively rotatable elements are generally a spring seat or bearing and an elastic damping element. For assuring a proper functioning of the spring bearing, particularly of the rolling bearing, it is necessary to protect the bearing components from pollutants such as road dust and humidity.
A suspension strut of the pre-cited type known from DE 69 001 377 T2 comprises a bearing having two bearing rings in which ball-shaped rolling elements are guided. The bearing rings are nested in plastic retention elements which are arranged centered in axially spaced carrier elements made of steel.
Besides being an expensive construction, this known bearing arrangement does not possess adequate rigidity for an elastic damping element, for example, a rubber-cushioned upper carrier element. In addition, this bearing arrangement with its many components requires a large design space.
OBJECTS OF THE INVENTION
It is an object of the invention to eliminate the aforesaid drawbacks by creating an economic mounting arrangement for a suspension strut offering adequate rigidity while being further optimized with respect to design space requirement and number of components.
This and other objects and advantages of the invention will become obvious from the following detailed description.
SUMMARY OF THE INVENTION
In the suspension strut bearing of the invention, the bearing rings of the rolling bearing are supported and centered directly on carrier elements. The only components making up the bearing of the invention are rolling elements guided in bearing rings which are surrounded by carrier elements, the bearing rings being centered on rims of the carrier elements which point axially towards each other. Compared to the prior art, the bearing of the invention has an improved rigidity as well as a clearly reduced number of components so that the design space requirements of the bearing is likewise reduced. Due to the characteristic structure of suspension struts, forces are introduced into the bearing obliquely so that the carrier elements are differently loaded. According to the invention, the structure of the carrier elements is adapted to their specific loading i.e., they have different configurations from each other and are made of different materials. Preferably, the carrier element which is supported on an elastic damping element is made of a material of higher strength so that it can have a relatively thin-walled configuration and still possess adequate strength. The weight and size optimized suspension strut bearing of the invention is further characterized by a small number of components which results in a cost advantage. The invention also covers carrier elements which can be made chiplessly by deep drawing or by injection molding. A further advantage of the invention is that the coil spring is supported directly on one of the carrier elements.
In one embodiment of the invention, the bearing is surrounded by carrier elements having rims which are radially offset to each other for centering the bearing. Alternatively, the rims of the carrier elements which point axially towards each other are associated to the inner sides of the bearing rings which are thus centered on the inside.
In a further advantageous embodiment of the invention, the rim of one of the carrier elements centers one of the bearing rings on the inside while the rim of the other carrier element centers the second ring on the outside.
In a preferred embodiment of the invention, one of the carrier elements is made of steel sheet while the other carrier element is made of plastic. The invention also covers the combination of a carrier element made of aluminium with a carrier element made of plastic. Alternatively, the suspension strut of the invention may also be provided with carrier elements made of other materials.
Preferably, the carrier element associated to the vehicle body is made of plastic and the carrier element associated to the coil spring of the suspension strut is made of steel sheet. Such an arrangement of the carrier elements prevents a transmission of structure-borne noise from the wheel guide to the vehicle body. For a further insulation of structure-borne noise, a damping disc can be arranged between the carrier element concerned and the vehicle body.
According to an advantageous feature of the invention, the carrier element made of plastic has a pot-shaped configuration and comprises on its inner and its outer side, a circumferential rim pointing towards the coil spring.
A further measure provided by the invention for reducing the manufacturing costs of the bearing is to use a wire as a base material for making the bearing rings. The wire is first shaped into a ring-shape and the ends of the wire are welded together before the rolling element raceway is formed on one side of the wire ring by axial stamping. Such a method of a chipless manufacturing of the bearing rings possesses a further potential for cost saving and can thus contribute to an economic manufacture of the rolling bearing as a whole. The drawing process by which the wire is made effects a work hardening of the material of the wire. This hardening is maintained even in the chiplessly stamped rolling element raceways of the invention which thus do not differ from the usual type of bearings with regard to strength and durability.
To improve the natural rigidity of the steel sheet carrier elements which in the installed position is remote from the coil spring, this carrier element comprises a bottom with a radially multi-stepped configuration. Said carrier element further comprises both on an inner and an outer side a circumferential rim pointing towards the coil spring. The other carrier element of the suspension strut is made of plastic. This carrier element made preferably as a plastic injection molding extends in the installed state to near the inner contour of the other carrier element forming a gap therewith.
To optimize its weight, the plastic carrier element is configured with chamber-like recesses which are arranged preferably concentrically therewithin and open towards the other carrier element which is made of steel sheet. To provide an adequate rigidity, the chamber-like recesses are interrupted by radially dispensed webs and web walls.
According to a further feature of the invention, the carrier elements engage into each other in the installed state. This is achieved by the fact that the rims of the steel carrier element engage around end regions of an inner and outer wall of the plastic carrier element. This measure prevents a detrimental penetration of pollutants and humidity into the suspension strut bearing. A further measure provided by the invention for improving sealing is to make at least parts of an end region of a wall of the plastic carrier element with a stepped configuration which results in the formation of a elongated, labyrinth-like sealing gap in the region of overlap of the carrier elements.
According to still another feature of the invention, the two carrier elements are secured to each other by positive engagement to form a pre-assembled unit including all the components of the suspension strut bearing. A simple and effecti

Affiliated with

Also associated with

Rating

Suspension strut bearing does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Suspension strut bearing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Suspension strut bearing will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2561285