The present invention pertains to an elastomer bearing with an inner part, an outer sleeve, which surrounds the inner part coaxially to a bearing longitudinal axis defining the center of the bearing, and with an elastomer body, which is arranged between the inner part and the outer sleeve.
Elastomer bearings are used in motor vehicles to absorb vibrations of various frequency ranges. To achieve the desired absorption, an elastomer body is accordingly arranged between an inner part and an outer sleeve in prior-art elastomer bearings. Rubber, which can be prepared from natural rubber and whose properties can be varied by adding additives, is used mostly as the elastomer body, so that absorption characteristics corresponding to the particular requirements can be obtained with the prior-art elastomer bearings. However, the steadily increasing requirements on elastomer bearings for use in motor vehicles make it necessary to increase the number of variants.
An elastomer bearing, in which the elastomer body arranged between the inner part and the outer sleeve has a bulge and at least one tapered section each is present adjacent to the bulge when viewed in the direction of the longitudinal axis of the bearing, is known from U.S. Pat. No. 5,820,115. The bulge of the elastomer bearing described in the document meshes with a groove-like depression of the inner part. Axial excursion of the elastomer bearing between the inner part and the outer sleeve is said to be prevented by this measure.
A solution similar to that described before also appears from U.S. Pat. No. 1,827,233. A class-forming design of an elastomer bearing is shown especially in
Experiments have shown that axial mobility of the elastomer body between the inner part and the outer sleeve cannot be effectively prevented from occurring by a groove-like depression on the inner part, with which the bulge of the elastomer body meshes. Additional axial stops are rather necessary in the embodiment variants on the front side in order to prevent the elastomer body from yielding in the axial longitudinal direction. It is just as impossible to achieve high radial stiffness, i.e., low mobility of the outer sleeve relative to the inner part, during loading in the direction at right angles to the longitudinal axis of the bearing, with the prior-art elastomer bearings as an effective axial supporting of the elastomer body without contact areas to be provided additionally on the elastomer body. Such complex requirements cannot be met with the solutions known from the state of the art. It is known that reinforcing elements can be introduced as intermediate layers into the elastomer body in order to thus increase the strength of the elastomer in the radial direction. Not only do the material and manufacturing costs increase as a result, but the necessary external dimensions become larger as well, which is disadvantageous in view of the limited space available for installation in modern motor vehicles.
The basic object of the present invention is to provide an elastomer bearing that has high radial stiffness, axial stability of the elastomer body, low torsion-proofness and longer service life compared to prior-art embodiments. Furthermore, the largest possible number of variants shall be obtained along with a simple design.
An elastomer bearing according to the present invention is accordingly characterized in that the outer sleeve has axial end sections with a deformation each, which is directed towards the inside of the bearing, and that before the elastomer bearing is mounted in a motor vehicle component, the elastomer body has recesses on the axial front sides of the elastomer bearing, which said recesses are filled by the elastomer body up to the area of the deformations after the elastomer bearing has been inserted into the motor vehicle component.
Several requirements imposed on such an elastomer bearing for use in a motor vehicle can be met with an elastomer bearing according to the present invention. The very high radial stiffness, i.e., the relatively low mobility of the outer sleeve relative to the inner part in the direction extending at right angles to the longitudinal axis of the housing, is achieved by the partially enlarged elastomer volume, which is present approximately in the center of the bearing as a consequence of the bulge. As a consequence of this, these axial end areas of the elastomer bearing have tapered sections. However, the advantageous overall absorption characteristics of the elastomer bearing according to the present invention are also made possible by the deformations present on the front side, which prevent the axial excursion of the elastomer body at least partially. The required low torsion-proofness of the elastomer bearing according to the present invention is affected by the properties of the elastomer body, which predetermines the parameters that are decisive for this due to its inner molecular structure if there is a connection in substance between the elastomer body, the inner part and the outer sleeve. However, it is likewise possible that the elastomer body is connected only to the inner part or to the outer sleeve in an adherent manner in order to obtain a torsionally weak design.
On the whole, a very simple design, which can be manufactured at low cost and requires only a few standardized individual parts in the form of a modular system, was created with the elastomer bearing according to the present invention.
Corresponding to an embodiment of the present invention, it is proposed, furthermore, that the fiber length of the elastomer be greater in the area of the bulge than in the adjacent tapered sections. The radial stiffness of the elastomer bearing as a whole can be improved by this difference in the fiber lengths. Moreover, the axial mobility of the elastomer bearing can also be influenced hereby, however.
To meet the need for an elastomer bearing that can be used with the smallest possible number of individual parts for different motor vehicles and applications, a kind of modular system is proposed. This can be embodied by standardized components, which are modified in details only corresponding to the requirements imposed on the elastomer bearing. Thus, a highly advantageous embodiment of the present invention is based on the fact that the inner part has a groove-like depression, which receives the bulge of the elastomer body.
To increase the possibilities of combination, it is proposed, furthermore, that inserts made of a material different from the material of the inner sleeve of the inner part be inserted into the depression. However, the insert may also be introduced into the depression of the inner part by means of a connection in substance, for example, by means of an injection process or in another manner. It is thus possible to use a uniform, standardized inner part with a depression, into which modularly different inserts can be introduced, depending on the requirements imposed on the elastomer bearing and the elastomer to be used, so that the width of the bulge of the elastomer body can be varied hereby.
To influence the characteristics of the elastomer bearing, collars present on the axial front sides are advantageous, for example, to limit the freedom of motion of the elastomer body in the axial direction. These collars can be produced by partially expanding the inner part, but it is just as possible to arrange the collars on the inner part later.
An especially simple variant of the present invention may be to provide the inner part with a continuously regular cylindrical geometry. This embodiment makes possible a high level of variability in terms of the shaping of the inner part.
Thus, it is possible, for example, to attach the aforementioned collars on the uniformly standardized inner part or to provide the outer sleeve with a bulged expansion, with which the bulge of the elastomer body meshes. Furthermore, such an embodiment of the inner part makes it possible to arrange at least one jacket with a central depression, into which the bulge of the elastomer body is inserted, on the outer surface. Providing a jacket each on the axial end sections of the inner part is also within the scope of the present invention, in which case the jackets should be located at spaced locations from one another when viewed in the direction of the longitudinal axis of the bearing, so that a groove-like depression, which is used to receive the bulge of the elastomer body, is formed between the jackets.
Insofar as a groove-like depression is mentioned in connection with the present invention, this may be provided as a circumferential depression or as a depression located in some sections on the inner part or on the outer sleeve.
It is common to the aforementioned suggestions that the central area of the elastomer body, which is present approximately in the center of the bearing, has a bulge, which meshes with a complementarily shaped depression of the inner part or of the outer part, so that a greater height of the elastomer body can be achieved at least in some sections in this central area when viewed in the cross section, and the requirements imposed on the elastomer bearing in terms of radial stiffness can be met.
The inserts of the collars and/or the at least one jacket may consist of a plastic in an elastomer bearing according to the present invention or manufactured from another material, for example, a material that can be processed by injection molding. Inserts or collars or jackets made of metals such as aluminum or other materials are conceivable as well.
In order not to influence the properties of the elastomer body in an undesired manner, it is advantageous to provide the outer sleeve of the elastomer bearing with a jacket surface that is closed in itself over its circumference.
To influence the properties of the elastomer bearing according to the present invention, it is advantageous, moreover, to calibrate same by radial deformation of the inner part and/or the outer sleeve before it is installed in the motor vehicle component. Either the external dimensions of the outer sleeve are reduced and/or the external dimensions of the inner part are enlarged, i.e., widened. The elastomer body is prestressed by the calibration. The final requirements imposed on the elastomer bearing in terms of the properties of the elastomer body are attained by the final installation of the elastomer bearing in the motor vehicle component.
It shall be mentioned in connection with the elastomer bearing according to the present invention that it is possible in the sense of the solution being proposed that the elastomer body has a connection in substance to the inner part and/or the outer part, so that at least there is an adherent connection between the elastomer body and at least one of the parts of the elastomer body. The adherent connection may be produced already during the vulcanization process of the elastomer or later. The torsion-proofness of the elastomer body can be reduced by such a measure to such an extent that the elastomer body possesses sliding properties to a limited extent.
However, an adherent connection is not obligatory, so that one embodiment of the present invention also provides for a design in which the elastomer body is only inserted between the inner part and the outer sleeve without there having to be an adherent connection.
Moreover, it is useful in the course of the simplification of the design of an elastomer bearing according to the present invention to design the elastomer bearing as a whole as a radially symmetrical bearing.
The solution according to the present invention leads, on the whole, to an elastomer bearing that guarantees high radial stiffness with low torsion-proofness. It has a very simple design and can be composed from standardized components in the sense of a modular system according to the requirements imposed on the elastomer bearing for different vehicle models. An undercut is created by the bulge of the elastomer body in the central area of the elastomer bearing. The parameters of the elastomer bearing can be set very meticulously by calibrating the elastomer body. The axial load-bearing capacity is limited essentially by the deformation of the outer limit or by the expansion or the formation of collars on the outer jacket of the inner part. A longer elastomer fiber is obtained due to the elastomer body designed according to the present invention in the central area, in which the bulge is located, than in the tapered sections located adjacent to this bulge, so that there is a reduced fiber length in the tapered sections compared to the bulge.
Various preferred embodiments of an elastomer bearing according to the present invention will be explained in more detail below on the basis of the drawings.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.
In the drawings:
Referring to the drawings in particular, the exemplary embodiment of an elastomer bearing according to the present invention, designated as a whole by 1, which is shown in
After the elastomer bearing 1 has been installed in the motor vehicle component 11, the recesses 12 and 13 of the elastomer body 5 are largely filled, as was already described in connection with the first embodiment, so that the elastomer body 5 extends up into the area of the deformations 9 and 10 in the axial direction.
The geometry of the outer sleeve 4 corresponds in this embodiment variant to the view in
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
Number | Date | Country | Kind |
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10 2004 045 064.1 | Sep 2004 | DE | national |
This application is a United States National Phase application of International Application PCT/DE2005/001611 and claims the benefit of priority under 35 U.S.C. §119 of German Patent Application DE 10 2004 045 064.1 filed Sep. 15, 2004, the entire contents of which are incorporated herein by reference.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/DE05/01611 | 9/14/2005 | WO | 7/5/2007 |