Bearings, especially bushing bearings and their corresponding bearing assemblies

Abstract

This invention relates to a bearing (2), particularly a bushing bearing (2), comprising: an outer sleeve (4) including a central sleeve opening (6) extending along a longitudinal bearing axis (L); a decoupling bushing (8) received in the central sleeve opening (6) of the outer sleeve (4), the decoupling bushing (8) including a central opening (10) extending along the longitudinal bearing axis (L); and a core element (12) received in the central opening (10) of the decoupling bushing (8), wherein the decoupling bushing (8) is made of microporous polyurethane. According to the invention, the decoupling bushing (8) has variable damping characteristics and / or stiffness in the circumferential direction (U) about the longitudinal axis (L).

Description

[0001] The present invention relates to a bearing, particularly a bushing bearing, comprising: an outer sleeve including a central sleeve opening extending along a longitudinal bearing axis; a decoupling bushing received in the central sleeve opening of the outer sleeve, the decoupling bushing including a central opening extending along the longitudinal bearing axis; and a core element received in the central opening of the decoupling bushing, wherein the decoupling bushing is made of microporous polyurethane.

[0002] The aforementioned type of bearing is known in the prior art. These bearings exhibit excellent damping characteristics in chassis and powertrain component mountings, particularly due to the use of microporous polyurethane. However, it should be considered that bearings of this type, including decoupling bushings made of microporous polyurethane, must primarily withstand compressive stresses due to their microporous structure. The use of microporous polyurethane in bushing bearings is limited to applications requiring direction-independent damping characteristics.

[0003] A bushing bearing with orientation-dependent damping characteristics is known from WO 2008 / 058914. To address this, additional polyurethane damping elements have been proposed to adjust the orientation-dependent damping characteristics. However, this increases the mechanical complexity of the bushing bearing, making it more difficult to assemble and manufacture.

[0004] Therefore, the object of the present invention is to provide a bearing of the type described at the beginning, which overcomes the aforementioned problems as much as possible. In particular, the object of the present invention is to provide a bearing, especially a bushing bearing, which includes direction-dependent stiffness and damping characteristics, particularly in the two radial directions, and which is easier to manufacture and less complex.

[0005] The present invention achieves the above-mentioned objective by providing a bearing according to claim 1, particularly a bushing bearing. According to the invention, the decoupling bushing has variable damping characteristics in the circumferential direction about the longitudinal axis. By providing a decoupling bushing with variable damping characteristics in the circumferential direction about the longitudinal axis, the bushing bearing is formed by only three components. This reduces the manufacturing complexity of the bearing. Furthermore, the bearing can be assembled with fewer assembly steps, and the overall cost of the bearing can be reduced.

[0006] According to one embodiment, the bearing includes a first radial direction and a second radial direction, the second radial direction being orthogonal to the first radial direction, and wherein the inner and / or outer contours of the decoupling bushing have a greater radial extension from the longitudinal bearing axis in the first radial direction than in the second radial direction. By adjusting the radial extension of the inner and / or outer contours from the longitudinal bearing axis of the decoupling bushing, direction-dependent stiffness and damping characteristics can be designed into the decoupling bushing.

[0007] According to one alternative embodiment, the decoupling bushing comprises a substantially constant radial thickness in its uncompressed state. Thus, the direction-dependent damping characteristics can be adjusted primarily by regulating the radial extension of the inner and / or outer contours of the decoupling bushing.

[0008] According to one embodiment, the decoupling bushing includes a first curved surface extending in a second radial direction, a second curved surface extending opposite to the first curved surface, a third curved surface extending toward the first radial direction, and a fourth curved surface extending opposite to the third curved surface. Specifically, these four curved surfaces are arranged adjacent to each other in the circumferential direction. The curved surfaces preferably include chords, wherein the chords extend perpendicular to the radial direction in which the curved surfaces extend. For example, the chord of the first curved surface may extend perpendicular to the second radial direction. The chord of the third curved surface may extend perpendicular to the first radial direction.

[0009] The proposed design of a decoupled bushing with four curved surfaces allows for tuning of direction-dependent damping characteristics.

[0010] According to one embodiment, the first and second curved surfaces have larger radii than the third and fourth curved surfaces. The damping characteristics can be adjusted by regulating the surface radii.

[0011] In one embodiment, the decoupling bushing is non-adhesively housed between the outer sleeve and the core element. This means that the bushing bearing can be manufactured more easily, wherein the decoupling bushing, outer sleeve, and core element can be moved relative to each other after the bushing bearing has been installed.

[0012] According to one embodiment, the outer contour of the core element and / or the inner contour of the outer sleeve have a greater radial extension from the longitudinal bearing axis in the first radial direction than in the second radial direction. By modeling the outer contour of the core element and the inner contour of the outer sleeve such that these contours have a greater radial extension from the longitudinal bearing axis in the first radial direction than in the second radial direction, the orientation-dependent characteristics of the bearing element can be further influenced.

[0013] According to one embodiment, the inner contour of the outer sleeve and / or the outer contour of the core element cause the decoupling bushing to elastically deform in order to preload the decoupling bushing, particularly in a direction-dependent manner. By designing the internal geometry of the outer sleeve and the external geometry of the core in the described manner, the curved surfaces of the decoupling bushing are compressed under load in two radial directions, thereby allowing the bearing stiffness to be defined as a function of direction. For example, the first and second curved surfaces of the decoupling bushing can be compressed to a greater extent than the third and fourth curved surfaces, thereby providing direction-dependent damping characteristics to the bushing bearing itself.

[0014] According to one embodiment, the outer contour of the core element and / or the inner contour of the outer sleeve includes a first curved surface extending in a second radial direction, a second curved surface extending opposite to the first curved outer surface, a third curved surface extending toward the first radial direction, and a fourth curved surface extending opposite to the third curved surface, wherein the first and second curved surfaces have radii larger than the third and fourth curved surfaces. Alternatively, the radii may be equal. By providing curved surfaces for the outer contours of the core element and the outer contour of the outer sleeve, wherein the first and second curved surfaces have radii different from the third and fourth curved surfaces, the preload of the decoupling bushing arranged between the outer contour of the core element and the inner contour of the outer sleeve can be further adjusted to model the direction-dependent damping characteristics of the bearing.

[0015] According to one embodiment, the outer sleeve includes an outer contour that is rotationally symmetrical about the longitudinal bearing axis. When such a circular outer sleeve is pressed into an elliptical bearing bore, this results in a direction-dependent pre-compression ratio. According to an alternative embodiment, the outer contour of the outer sleeve is elliptical in the circumferential direction about the longitudinal bearing axis. This provides another way to preload or pre-compress the decoupled bushing in various radial directions. In this way, another adjustment mechanism is provided to adjust the direction-dependent stiffness and damping characteristics of the bearing.

[0016] Specifically, the outer contour comprises an elliptical dimension relative to the bearing bore into which the bearing is intended to be inserted. When the bearing is inserted into the bearing bore, the oversized outer sleeve and its elliptical outer contour result in a direction-dependent pre-compression of the decoupling bushing, thereby providing direction-dependent damping characteristics. In a preferred embodiment, the degree of compression of the decoupling bushing can be between 0% and 50%. According to one embodiment, the damping characteristics of the bearing can be modeled by selectively adjusting the pre-compression of the decoupling bushing.

[0017] Since the damping characteristics of microporous polyurethane materials depend on the degree of compression, this effect can be used to adjust direction-dependent damping characteristics. According to one embodiment, pre-compression is adjusted such that when the bearing deflects more, the static friction between the decoupling bushing and the core element is overcome, and the friction generated between the decoupling bushing and the core additionally increases damping. This allows for improved damping characteristics in the radial direction without the decoupling bushing experiencing excessive shear.

[0018] According to one embodiment, the central opening of the decoupling bushing includes a radial recess, in which the core element can be slidably received. In other words, if one or more recesses are introduced between the decoupling bushing and the core element in the radial direction, the core element can slide within these recesses. This is also advantageous in manufacturing because bonding is not required.

[0019] The pre-assembly of the bearing is carried out with little or no pre-compression of the decoupling bushing, meaning the assembly force is very low. Pre-compression is then applied in the step of pressing the bearing into the bearing bore by compressing an oversized outer sleeve.

[0020] In one embodiment, the decoupling bushing includes a resilient collar extending radially outward from the end face of the decoupling bushing. The resilient collar can be pre-compressed, for example, by means of an axial washer threaded to the support, within a range of 0% to 50%. This allows for adjustment of the axial bearing stiffness.

[0021] In another aspect, the present invention relates to a decoupling bushing for a bearing according to any one of the foregoing embodiments, the decoupling bushing comprising a central opening extending along the longitudinal bearing axis, wherein the decoupling bushing is made of microporous polyurethane. The decoupling bushing achieves its essential purpose by having variable damping characteristics in the circumferential direction about the longitudinal axis. The decoupling bushing according to the invention utilizes the same advantages and preferred embodiments as the bearing. Therefore, the preferred embodiments of the decoupling bushing are also the preferred embodiments of the bearing, and vice versa.

[0022] In another aspect, the present invention relates to a bearing assembly. The basic objective of the invention is that the bearing assembly includes a circular bearing bore and a bearing according to any one of the foregoing embodiments, the bearing being inserted into the circular bearing bore.

[0023] In another aspect, the present invention also relates to the use of bearings. The basic objective of the present invention is to use the bearing according to any one of the foregoing embodiments, particularly the bearing assembly according to the foregoing embodiments, in a bearing assembly.

[0024] The bearing assembly utilizes the advantages and preferred embodiments of the bearing and decoupling bushing of the present invention. The preferred embodiments of the bearing and decoupling bushing are also preferred embodiments of the bearing assembly and its application, and vice versa.

[0025] In a preferred embodiment, a microporous polyurethane elastomer is particularly preferred, having a density of 200 kg / m³ to 1100 kg / m³, preferably 300 kg / m³ to 800 kg / m³, according to DIN 53420; a tensile strength of 2 N / mm², preferably 2 N / mm² to 8 N / mm², according to DIN 53571; an elongation of 300%, preferably 300% to 700%, according to DIN 53571; and a tear strength of preferably 8 N / mm to 25 N / mm, according to DIN 53515.

[0026] The elastomer is preferably a microporous elastomer based on polyisocyanate addition polymerization products, preferably having pores with a diameter of 0.01 mm to 0.5 mm, particularly preferably 0.01 mm to 0.15 mm.

[0027] Elastomers based on polyisocyanate addition polymers and their preparation are well known and are extensively described in, for example, EP A62 835, EP A 36 994, EP A 250 969, DE A 195 48 770 and DE A 195 48 771.

[0028] Preparation is usually carried out by reacting the isocyanate with a compound that is reactive to the isocyanate.

[0029] Elastomers based on porous polyisocyanate addition polymerization products are typically prepared in a mold, where reactive starting components react with each other. Suitable molds here are generally conventional molds, such as metal molds, whose shape ensures the three-dimensional shape according to the invention.

[0030] Polyisocyanate addition polymers can be prepared according to commonly known methods, for example, by using the following starting materials in a one-stage or two-stage process: (a) Isocyanates, (b) Compounds that are reactive to isocyanates (c) Water and optional land (d) Catalyst, (e) foaming agents and / or (f) Additives and / or supplements, such as polysiloxanes and / or fatty acid sulfonates.

[0031] The surface temperature of the mold inner wall is typically 40°C to 95°C, preferably 50°C to 90°C. Molding is advantageously carried out at an NCO / OH ratio of 0.85 to 1.20, wherein heated starting components are mixed and introduced into a heated, preferably tightly closed molding tool in an amount corresponding to the desired molding density. The molding is cured for 5 to 60 minutes and can then be removed from the mold. The amount of reaction mixture introduced into the molding tool is typically determined in such a manner that the resulting molded body has the given density. The starting components are typically introduced into the molding tool at a temperature of 15°C to 120°C, preferably 30°C to 110°C. The compressibility used to prepare the molded body is between 1.1 and 8, preferably between 2 and 6. Porous polyisocyanate addition polymers are conveniently prepared in an open or preferably closed molding tool by a "one-step" method, using high-pressure technology, low-pressure technology, or particularly reaction injection molding (RIM). The reaction is carried out, in particular, by compression within a closed molding tool. Reaction injection molding techniques are described, for example, in the following literature: H. Piechota and H. Röhr, “Integralschaumstoffe”, Carl Hanser-Verlag, Munich, Vienna, 1975; D. J. Repelka and J. L. Wharton, Journal of Cellular Plastics, March / April 1975, pp. 87-98; and U. Knipp, Journal of Cellular Plastics, March / April 1973, pp. 76-84.

[0032] To gain a more complete understanding of the invention, it will now be described in detail with reference to the accompanying drawings. The detailed description will illustrate and describe what are considered to be preferred embodiments of the invention. It should be understood, of course, that various modifications and changes in form or detail can be readily made without departing from the spirit of the invention. Therefore, the invention is not limited to the exact forms and details shown and described herein, nor is it limited to all of the invention less than what is disclosed herein and claimed below. Furthermore, features described in the specification, drawings, and claims that disclose the invention may be necessary for the invention to be considered individually or in combination. In particular, any reference numerals in the claims should not be construed as limiting the scope of the invention. The word "comprising" does not exclude other elements or steps. The words "a" or "an" do not exclude a plurality.

[0033] The invention will now be described with reference to the accompanying drawings, which illustrate, by way of example and not limitation, one of several possible embodiments of the bearing proposed herein, and wherein: Figures 1 to 3A first embodiment of the bearing according to the invention is shown in different views; Figure 4 and Figure 5 Embodiments of the bearing assembly according to the present invention are shown in different views; Figure 6 An alternative embodiment of the bearing assembly is shown in cross-sectional view.

[0034] Figures 1 to 3 A first embodiment of a bearing 2 is shown, which is configured as a bushing bearing 2. The bearing 2 includes an outer sleeve 4. The outer sleeve 4 includes a central sleeve opening 6 extending along the longitudinal bearing axis L. The bearing 2 also includes a decoupling bushing 8. The decoupling bushing 8 is received within the central sleeve opening 6 of the outer sleeve 4. The decoupling bushing 8 includes a central opening 10 extending along the longitudinal bearing axis L. The bearing 2 also includes a core element 12. The core element 12 is received within the central opening 10 of the decoupling bushing 8. The decoupling bushing 8 is made of microporous polyurethane. Furthermore, the decoupling bushing 8 has variable damping characteristics in the circumferential direction U about the longitudinal axis L.

[0035] Specifically, bearing 2 includes a first radial direction X and a second radial direction Y, the second radial direction Y being orthogonal to the first radial direction X, and wherein the damping characteristics and / or stiffness vary between the first radial direction X and the second radial direction Y. Decoupling bushing 8 includes an inner contour 14 and an outer contour 16. The inner contour 14 and outer contour 16 of decoupling bushing 8 have a greater radial extension R from the longitudinal bearing axis L in the first radial direction X than in the second radial direction Y. This allows for adjustment of the damping characteristics and stiffness of decoupling bushing 8. Decoupling bushing 8 includes a radial thickness T. In the uncompressed state of decoupling bushing 8, the radial thickness T can be substantially constant. Figure 1 and Figure 2 As specifically shown, the decoupling bushing 8 includes a first curved surface 18a extending in a second radial direction Y and a second curved surface 18b extending opposite to the first curved surface 18a in a direction opposite to the radial direction Y. The decoupling bushing 8 also includes a third curved surface 20a extending toward a first radial direction X and a fourth curved surface 20b extending opposite to the third curved surface 20a in a direction opposite to the first radial direction X. The first curved surface 18a and the second curved surface 18b have a larger radius extension R than the third curved surface 20a and the fourth curved surface 20b. The radius extension R may also be equal.

[0036] The decoupling bushing 8 is non-adhesively housed between the outer sleeve 4 and the core element 12. In other words, the decoupling bushing 8 is not bonded to the outer sleeve 4 and the core element 12. The outer contour 24 of the core element 12 has a greater radial extension R from the longitudinal bearing axis L in the first radial direction X than in the second radial direction Y. Furthermore, the inner contour 22 of the outer sleeve 4 has a greater radial extension R from the longitudinal bearing axis L in the first radial direction X than in the second radial direction Y. Thus, the inner contour 22 of the outer sleeve 4 and the outer contour 24 of the core element 12 cause the decoupling bushing 8 to elastically deform in order to preload the decoupling bushing 8. In this way, direction-dependent damping characteristics are achieved.

[0037] The outer contour 24 of the core element 12 includes a first curved surface 30a extending in the second radial direction Y, a second curved surface 30b extending opposite to the first curved outer surface, a third curved surface 32a extending in the first radial direction X, and a fourth curved surface 32b extending opposite to the third curved surface 32a. The inner contour 22 of the outer sleeve 4 includes a first curved surface 26a extending in the second radial direction Y, a second curved surface 26b extending opposite to the first curved outer surface 26a, a third curved surface 28a extending toward the first radial direction X, and a fourth curved surface 28b extending opposite to the third curved surface 28a. The first curved surfaces 26a, 30a and the second curved surfaces 26b, 30b have a radius r larger than the third curved surfaces 28a, 32a and the fourth curved surfaces 28b, 32b. The radii can also be equal.

[0038] The outer sleeve 4 includes an outer contour 34, wherein the outer contour 34 is elliptical in the circumferential direction U around the longitudinal bearing axis L. For example... Figure 2 As shown, the outer contour 34 of the outer sleeve 4 has an elliptical shape with dimensions A x B, where dimensions A and B are different from each other. Furthermore, as... Figure 1 As shown, the decoupling bushing 8 includes a resilient collar 36. The resilient collar 36 extends radially outward from the end face 38 of the decoupling bushing 8.

[0039] Figure 4 and Figure 5 Bearing assembly 100 is shown. Bearing assembly 100 includes a circular bearing bore 102 and a bearing 2. The bearing 2 is inserted into the circular bearing bore 102. Figure 4 As shown, the elastic collar 36 is pre-compressed by a screw 42, which acts on the bracket 44 and the axial washer 40, thereby compressing the decoupling bushing 8. The axial pre-compression of the decoupling bushing 8 is in the range of 0% to 50%.

[0040] from Figure 5As can be clearly seen, the circular bearing bore 102 includes an inner diameter D, wherein the bearing bore is circular. However, the outer sleeve 4 is elliptical, such that when the bearing 2 is pressed into the circular bearing bore 102, different interference fits produce a direction-dependent pre-compression of the decoupling bushing 8. This radial pre-compression can be between 0% and 50%.

[0041] exist Figure 6 In one embodiment, the central opening 10 of the decoupling bushing 8 includes a radial recess 44. The core element 12 is slidably received within the radial recess 44. This overcomes the static friction between the decoupling bushing 8 and the core element 12 as the core element 12 deflects further, and additional damping is provided by the friction generated between the core element 12 and the decoupling bushing 8. This also allows for the avoidance of significant shear forces on the decoupling bushing 8.

[0042] List of reference numerals 2 bearings / bushel bearings 4 outer sleeves 6-center sleeve opening 8 Decoupling Bushing 10 Decoupling bushing center opening 12-core component 14. Inner contour of the decoupling bushing 16 Decoupling Bushing Outer Profile 18a, b First and second curved surfaces of the decoupling bushings The third and fourth curved surfaces of the 20a and b decoupling bushings 22 Inner contour of outer sleeve Outer contour of 24-core component The first and second curved surfaces of the inner contour of the outer sleeves 26a and b The third and fourth curved surfaces of the inner contour of the outer sleeves 28a and b The first and second curved surfaces of the outer contours of the 30a and b core components The third and fourth curved surfaces of the outer contours of core components 32a and b 34 Outer contour of the outer sleeve 36 Decoupling Bushing Elastic Collar 38. End face of decoupling bushing 40 axial washers 42 screws 44 supports 46 radial recess 100 bearing assembly 102 Circular Bearing Bore The height of ellipse A The length of ellipse B D-shaped bearing bore inner diameter L longitudinal bearing axis R radial extension r radius T radial thickness U-shaped direction X-first radial direction Y second radial direction

Claims

1. A bearing (2), particularly a bushing bearing (2), said bearing comprising: - Outer sleeve (4), the outer sleeve including a central sleeve opening (6) extending along the longitudinal bearing axis (L). - Decoupling bushing (8), the decoupling bushing being received in the central sleeve opening (6) of the outer sleeve (4), the decoupling bushing (8) including a central opening (10) extending along the longitudinal bearing axis (L), and - Core element (12), the core element being housed in the central opening (10) of the decoupling bushing (8), The decoupling bushing (8) is made of microporous polyurethane. The decoupling bushing (8) is characterized by having variable damping characteristics in the circumferential direction (U) around the longitudinal axis (L).

2. The bearing (2) according to claim 1. The bearing (2) includes a first radial direction (X) and a second radial direction (Y), wherein the second radial direction (Y) is orthogonal to the first radial direction (X). Furthermore, the inner contour (14) and / or outer contour (16) of the decoupling bushing (8) have a greater radial extension (R) from the longitudinal bearing axis (L) in the first radial direction (X) than in the second radial direction (Y).

3. The bearing (2) according to any one of the preceding claims. The decoupling bushing (8) has a substantially constant radial thickness (T) in the uncompressed state.

4. The bearing (2) according to claim 2 or 3. The decoupling bushing (8) comprises: - A first curved surface (18a) extending in the second radial direction (Y). - A second curved surface (18b) extending opposite to the first curved surface (18a). - A third curved surface (20a) extending toward the first radial direction (X), and - A fourth curved surface (20b) extending opposite to the third curved surface (20a).

5. The bearing (2) according to claim 4. The first curved surface (18a) and the second curved surface (18b) have a larger radius (r) than the third curved surface (20a) and the fourth curved surface (20b).

6. The bearing (2) according to any one of the preceding claims. The decoupling bushing (8) is non-adhesively housed between the outer sleeve (4) and the core element (12).

7. The bearing (2) according to any one of the preceding claims. The outer contour (24) of the core element (12) and / or the inner contour (22) of the outer sleeve (4) have a greater radial extension (R) from the longitudinal bearing axis (L) in the first radial direction (X) than in the second radial direction (Y).

8. The bearing (2) according to any one of the preceding claims. The inner contour (22) of the outer sleeve (4) and / or the outer contour (24) of the core element (12) cause the decoupling bushing (8) to elastically deform in order to preload the decoupling bushing (8), particularly in relation to orientation.

9. The bearing (2) according to claim 7 or 8. The outer contour (24) of the core element (12) and / or the inner contour (22) of the outer sleeve (4) include: - A first curved surface (26a, 30a) extending in the second radial direction (Y). - A second curved surface (26b, 30b) extending opposite to the first curved outer surface (26a, 30a). - A third curved surface (28a, 32a) extending toward the first radial direction (X), and - A fourth curved surface (28b, 32b) extending opposite to the third curved surface (28a, 30a). The first curved surface (26a, 30a) and the second curved surface (26b, 30b) may optionally have a larger radius (r) than the third curved surface (28a, 32a) and the fourth curved surface (28b, 32b).

10. The bearing (2) according to any one of the preceding claims. The outer sleeve (4) includes an outer contour (34) which is rotationally symmetrical about the longitudinal bearing axis (L).

11. The bearing (2) according to any one of the preceding claims. The outer contour (34) of the outer sleeve (4) is elliptical in the circumferential direction (U) around the longitudinal bearing axis (L).

12. The bearing (2) according to any one of the preceding claims. The decoupling bushing (8) includes a resilient collar (36) extending radially outward from the end face (38) of the decoupling bushing (8), and / or The central opening (10) of the decoupling bushing (8) includes a radial recess (44), and the core element (12) is slidably accommodated in the radial recess (44).

13. A decoupling bushing (8) for a bearing (2) according to any one of the preceding claims, the decoupling bushing (8) comprising a central opening (10) extending along the longitudinal bearing axis (L), wherein the decoupling bushing (8) is made of microporous polyurethane. Its features are, The decoupling bushing (8) has variable damping characteristics in the circumferential direction (U) around the longitudinal axis (L).

14. A bearing assembly (100) comprising a circular bearing bore (102) and a bearing (2) according to any one of the preceding claims inserted into the circular bearing bore (102).

15. Use of the bearing (2) according to any one of the preceding claims in a bearing assembly (100), particularly in a bearing assembly (100) according to claim 14.

Images