Patent Application
20060272907
This application is a continuation of PCT Application No. PCT/EP2004/011098 filed on Oct. 5, 2004, which claims priority to German Application No. 103 46 343.7 filed Oct. 6, 2003, the disclosures of which are incorporated by reference herein.
The present invention relates to a brake disc, which may be fastened to a wheel hub, in particular of a commercial vehicle. The brake disc has two concentric friction rings and a brake disc neck.
Brake discs of such type are used, for example, in so-called fixed-caliper brakes, in which the brake disc is embodied as a sliding disc, which is mounted so as to be axially displaceable on the wheel hub or on a wheel axle.
During braking, the brake disc is pressed by a first brake shoe against an opposing second brake shoe, the respective contact faces of the brake disc being formed by the friction rings.
In order to compensate for the working stroke, which results, during each braking operation, from the air gap in the brakes which must be overcome, and for the elastic deformation of the brake linings and of the brake caliper, which occurs as force is applied, a brake disc is known from DE 101 48 681 A1 which is fastened to the wheel hub or wheel axle by an axially deflectable elastic connecting part. As a result, it is possible to dispense with previously conventional slide guides, by which the brake disc was held in an axially moveable manner, corresponding to the working stroke, on the wheel hub. The long-term operational reliability of the slide guides was restricted, in particular on account of, for example, dirt accumulation during operation.
The brake disc known from DE 101 48 681 A1 has proven itself in principle. However, the connecting part which is used here is formed in such a way that it can be connected to the brake disc only in the region of the friction rings. A desired application in a brake disc having a brake disc neck has not been possible with the known design.
The present invention is, therefore, based on further developing a brake disc of the above-mentioned type such that its service life is improved.
According to an aspect of the invention, the brake disc neck is fastened to the wheel hub by way of a connecting part, which connecting part is fixedly attached to the brake disc neck and may be elastically deformed axially relative to the friction rings.
The brake disc neck/friction rings structural unit is now axially moveable, corresponding to the required working stroke, without the need for guide elements, for example in the form of tongues and grooves as described in the prior art, for this purpose.
The connecting part is preferably formed as an annular spring element, which extends in the radial direction and is, therefore, capable of absorbing correspondingly acting forces.
This likewise applies to the fastening of the connecting part to the brake disc neck, which fastening is preferably positive and/or non-positive, the fastening being formed such that it is capable of absorbing torques acting on the friction rings during braking.
It is an advantage of the invention that it can be realized using simple design means, resulting not only in production being cost-effective, but also in practically fault-free operation.
The connecting element, which is formed as an annular spring element and completely surrounds the brake disc neck, is made from a material which permits long-term operation. This means that there are no spares costs and repair costs compared to the prior art when using the connecting part. The operational reliability of the brake disc is, therefore, likewise improved since wear-related operational faults are practically no longer possible.
The axial deformation behavior of the connecting part may be influenced by way of corresponding shaping.
Integrally formed corrugations, which run in a continuously or partially encircling manner on the spring element, are thus contemplated. As a result, a reduction in deformation forces in the axial direction is also obtainable, such as by the use of apertures which form a material weakening and, therefore, influence the shape behavior of the spring element.
The danger of radial deformation of the spring element as a result of torsional forces occurring during braking can be counteracted by providing an additional spring element, which is fixedly connected, together with the first spring element, to the wheel hub or wheel axle.
The torsional force absorption and thus the load on each spring element is varied as a function of the spacing between the two spring elements and/or of the spacing between the friction rings and the spring element which faces the latter.
High stability is also obtained if a spring element is likewise arranged in the interior of the brake disc neck, preferably in one plane with the friction rings. The spring element may rest in the wheel axle guided in the brake disc neck or may be connected to the wheel axle there. To reduce the axial deformation forces, that is to say to influence the spring force while simultaneously optimizing weight, the inner spring element may likewise be provided with corrugations or the like which are, for example, formed by material folds.
According to a further consideration of the invention, the connecting part, which is fastened to the outside of the brake disc neck, is provided with a cylindrical attachment which is connected to the brake disc neck and in a sense forms its extension.
A desired reduction in the axial deformation forces with simultaneously higher torque transmission can also be achieved when, in the connecting region to the brake disc neck, the outer and/or inner spring element has radially running tongues which are formed by recesses and engage in the brake disc neck in a positive and/or non-positive manner.
The arrangement of a plurality of spring elements, preferably two arranged in parallel and with a spacing to one another, additionally leads to effective counteraction of so-called wobbling of the brake disc, as can occur as a result of the torsional forces during braking.
In order to minimize warping of a brake disc without a brake disc neck, another embodiment provides two spring elements which are connected directly to the friction rings. The two spring elements are arranged in the plane of the brake disc with a spacing to one another and are connected to the wheel hub or wheel axle.
The spring elements may also be provided with corrugations in the form of folds or with recesses, one or both spring elements being correspondingly formed depending on requirements, in order to reduce the axial deformation forces.
Further advantageous embodiments of the inventions are described and claimed herein.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.
In addition, the brake disc 1 has a coaxial brake disc neck 3, in which a wheel axle of the vehicle can be guided.
A connecting part in the form of an annular spring element 4 is fixedly attached in a free end region, that is to say the end region which faces away from the friction rings 2, and is fastened to a wheel hub or the wheel axle.
The spring element 4 is elastically deformable axially relative to the friction rings 2, specifically to the extent defined by the working stroke of the disc brake
The spring element 4, which is otherwise arranged parallel to the friction rings 2, is preferably connected in a positive manner to the brake disc neck 3. A non-positive or cohesive connection is however also possible.
In the exemplary embodiment shown in
In order to increase the radial moment of resistance, and for an associated minimization of the radial deformation of the spring element 4, a second spring element 6 is fastened to the brake disc neck 3 parallel to the first spring element 4, as can be seen in
While, for example, in
Such an increase in stability may also be obtained by use of a second spring element 7 which, as shown in
In addition to the first spring element 4, the inner, second spring element 7 may also be provided with corrugations in the form of the folds 5, which are preferably situated on one side of the annular face, in order to reduce the axial deformation forces (see
Instead of the folds 5, the one spring element or both spring elements 4, 6 may be provided with recesses 8, as can be seen in
With this design, in addition to the mentioned reduction in the axial deformation forces, the braking torque (radial and axial) may also be transmitted without appreciable deformation.
In
A combination of the presented possibilities for reducing the axial deformation forces may be gathered from
The brake disc 1 shown in
A brake disc can be seen in
The connection of two inner spring elements 7 leads to a reduction in brake disc warping as can result from the braking torques which occur. In a manner already described, the spring elements 7 are also provided here with folds 5, by which the axial deformation resistance is reduced.
The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.
| Number | Date | Country | Kind |
|---|---|---|---|
| 103 46 343.7 | Oct 2003 | DE | national |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP04/11098 | Oct 2004 | US |
| Child | 11398611 | Apr 2006 | US |
