WO2016042055A1

WO2016042055A1 - Bearing assembly for the bearing of a shaft

Info

Publication number: WO2016042055A1
Application number: PCT/EP2015/071280
Authority: WO
Inventors: Holger Fröhlich
Original assignee: Continental Automotive Gmbh
Priority date: 2014-09-18
Filing date: 2015-09-17
Publication date: 2016-03-24
Also published as: DE102014218808A1

Abstract

The invention relates to a bearing assembly in a housing for the bearing of a shaft (4) in a first bearing position with a first bearing (2) or fixed bearing, and in a second bearing position, which is arranged axially at a distance from the first bearing position, with a second bearing (3) or floating bearing, wherein the second bearing (3) or floating bearing is introduced into a floating bearing bush (10), said floating bearing bush being formed by an inner sleeve (13) arranged on the second bearing (3) and a ring-shaped element (14) which is made of an elastic material, and which surrounds the inner sleeve (13) and is connected to same. The ring-shaped element (14) has a profiling at least on an outer surface and/or inside.

Description

description

The present invention relates to a bearing arrangement in a housing for supporting a shaft in a first bearing with a first bearing and in a second spaced from the first bearing second bearing with a second bearing. Bearing arrangements with two bearings are used in a variety of ways in the art. For example, from the document WO 2011/012456 AI a bearing assembly is known to be used in the bushes of elastic materials. This arrangement allows protection against a current passage and allows vibration damping in the radial direction. The disadvantage of this, however, is that the adjustment of the axial preload, taking into account the spring travel for tolerance compensation of the bearing on the floating bearing side only on the modulus of elasticity of the sleeve made of elastic material is possible. If one additionally takes into account the thermal load on the non-locating bearing, only very limited possibilities of this bearing arrangement result due to the choice of material.

The present invention is therefore an object of the invention to provide a bearing assembly which overcomes the above drawback, so with the reliable so that a required axial pre ^¬ voltage is achieved to z. B. ensure a slip-free operation and thus an increase in the bearing life. This object is achieved by a bearing ^¬ arrangement according to claim 1. Advantageous embodiments and further developments are described in the dependent claims.

A bearing assembly in a housing for supporting a shaft in a first bearing with a first bearing and in a spaced axially from the first bearing second bearing with a second bearing or movable bearing, wherein the second bearing or floating bearing used in a floating bearing bush is, has on the floating bearing bush on an inner sleeve which is arranged on the second bearing. In addition, an inner sleeve enclosing and connected to the inner sleeve annular member is provided made of an elastic material. The annular element has a profiling on at least one outer surface and / or in its interior.

By profiling, ie by adding additional unloaded surfaces or changing a ratio of contaminated surface to unloaded

Surface of the annular, so designed as a hollow cylinder element is achieved a lower shear stiffness and thus improves the axial spring properties of the floating bearing bushing. If the loaded surface is very large relative to the unloaded surface of such element, a large modulus of elasticity and a very small deformation will result. By changing the ratio of the loaded surface to the unloaded surface of the elastic element, the elastic behavior of the elastic element can be selectively influenced. As a result, the specifications for the axial

Preload of the second bearing or movable bearing in the respective application, which is characterized by spring travel, spring force and temperature, possible. Preferably, the annular element is provided on at least two opposite outer sides with the profiling in order to achieve an efficient adjustment of the desired properties. However, it may of course also be provided to provide the profiling on more than two of the outer sides, typically on all outer surfaces of the annular element.

It can also be provided that the elastic material of the annular element has the profiling in its internal structure. Thus, changes in the ratio of loaded to unloaded surface can be made both on an outer periphery and in the interior of the annular element for profiling. By using one of yourself From already provided with a characteristic inner profile material instead of a spatially homogeneous material, the desired adjustment on the profiling can be achieved quickly and efficiently without further action on the surface contour.

The annular element may be made of an elastomer, that is dimensionally stable, but elastically deformable and yet be resistant in these properties over a wide temperature range. Preferably, the annular member made of rubber, so vulcanized rubber or a polyurethane foam is formed. The use of a polyurethane foam is low due to excellent elasticity, oil and old weathering resistance ^¬. In addition, this vibration isolation to adjacent vibration sensitive

Components and a high degree of electrical insulation achieved. The Shore hardness of the rubber materials used can be between 30 ° and 90 °. Typically, the profiling is by at least one

Recess realized on an outer surface. Alternatively or additionally, at least one hollow chamber arranged in the interior of the annular element may form part of the profiling or the entire profiling. As a result, the profiling can be varied in order to achieve the desired mechanical properties of the annular element. It can also be provided to use a plurality of juxtaposed and spaced-apart rings as an annular element.

The annular element may alternatively or additionally be enclosed by an outer sleeve. Thus, the annular element and the outer sleeve are arranged radially one above the other on the inner sleeve.

Preferably, the inner sleeve and the annular element are positively and / or cohesively ver ^¬ bound together to ensure safe operation of the bearing assembly to währleisten. It can be provided that the inner sleeve and the annular element are connected to each other by gluing or by vulcanization. If the outer sleeve is used, this is typically likewise connected in a form-fitting and / or materially connected manner to the annular element. This can also be done by gluing or by vulcanization.

Alternatively or additionally, a coefficient of thermal expansion of a material of the outer sleeve is a maximum of 5 percent greater or smaller than a thermal expansion coefficient of the material of the housing to choose. This allows an adaptation of the two sleeves to the material contacting them in the bearing arrangement. If the thermal expansion coefficient of the bearing seat in the housing is too great, it may cause the outer sleeve in the housing seat to wander, which can lead to misalignment and tilting and thus increase wear.

Typically, the floating bearing is biased in the bearing assembly. To ensure a smooth running and to increase the service life, the axial preload should be one to two percent of the dynamic bearing yield. For engines subject to high vibration, the preload should be increased to three to four percent of the dynamic bearing yield.

An electric machine, typically with a rotor and a stator, may comprise the described bearing arrangement. It may be provided here that the rotor has a rotor shaft which is mounted in rotor bearings. The electric machine is typically used as a hybrid drive device in a motor vehicle.

Embodiments of the invention are illustrated in the drawings and are explained below with reference to FIGS 1 to 10. Show it:

1 shows a rotor bearing of electrical machines in a side sectional view;

Fig. 2 is an enlarged view of that shown in Fig. 1

Floating bearing;

Fig. 3 is a Fig. 2 corresponding view of another

Example of a floating bearing according to the invention;

Fig. 4 is a side view of a floating bearing bush with

several cavities inside; 5 is a view similar to FIG. 4 of a loose bearing bush with a plurality of recesses on top and bottom of an annular element; FIG.

Fig. 6 is a view similar to Figure 4 of a floating bearing bush with a plurality of recesses on the underside of an annular element.

Figure 7 is a side view of a built-floating bearing bush with zig-zag profiled annular element.

Fig. 8 is a view corresponding to Figure 7 with a ring-shaped member of polyurethane ^¬. Fig. 9 is a Fig. 7 corresponding view with a ring ^¬ shaped element in I-profile and

Fig. 10 several examples of profiles of the annular

Elements with unloaded and loaded surfaces.

An embodiment of a rotor bearing according to the invention is shown in Figure 1 in a side sectional view. In a motor housing 1, a fixed bearing 2 is arranged and axially spaced from the fixed bearing 2 a loose bearing 3 provided in a bearing plate 5. By the fixed bearing 2 and the movable bearing 3, a shaft 4 is mounted in the housing 1. In the movable bearing 3, a relative movement of the movable bearing 3 in the axial direction is possible. The fixed bearing 2 and the movable bearing 3 are designed as rolling bearings or deep groove ball bearings. The floating bearing 3 is also axially biased to ensure a sufficient minimum load or bias in the axial direction under all operating conditions. For this purpose, the floating bearing 3 is in contact with the bearing plate via a floating bearing bush 10.

A structure of the floating bearing bush 10 is shown enlarged in Figure 2. Recurring features are provided with identical reference numerals in this as well as in the following figures. The floating bearing 3 is arranged on the shaft 4 and via the Los ^¬ bearing bush 10, an inner sleeve 13, a form-fitting and cohesively inner sleeve 13 enclosing annular member 14 and the annular member 14 enclosing the outer sleeve 15, with the bearing plate 5 in contact , By the floating bearing bush 10, the axial bias, which corresponds to about two percent of a dynamic bearing yield of the floating bearing. The reference numeral 11 symbolizes a tolerance compensation for thermal expansion. The reference numeral 12 symbolizes a vibration damping.

The annular element 14 is in the illustrated embodiment ^¬ example of rubber. The inner sleeve 13 and the outer sleeve 15 are made of a metal, in the present embodiment of steel. On the outer sleeve 15 can be omitted in further embodiments. The inner sleeve 13 is the same as the Au ^¬ ßenhülse 15 connected positively and cohesively by vulcanization to the annular member 14, but may also be bonded in other embodiments. The annular element 14 has four recesses 16 on an upper side and a lower side facing each other. The recesses 16 are arranged tilted relative to a central axis of the movable bearing 10. Another embodiment of the movable bearing 10 is shown in Figure 3 in a figure 2 corresponding view. In contrast to the embodiment shown in Figure 2, the top and bottom of the annular member 14 are now closed, but four equally sized cavities 17 are provided in the interior of the annular member 14.

FIGS. 4 to 6 show a few basic examples for the design of a loose bearing bush. Figure 4 shows a side sectional view of the floating bearing bush 10 with the annular member 14 and cavities 17 in the rubber. In Figure 5, the floating bearing bush 10 is shown with attached on the top and bottom recesses 16 as another embodiment. As shown in FIG. 6, in further exemplary embodiments it is also possible to provide the recesses 16 only on one side, in the example shown only on the underside facing the inner sleeve 13.

In the figures 7 to 9 loose bearing bushes 10 are seen in various installation variants in a side view. In FIG. 7, the annular element 14 is profiled in a zigzag shape, that is to say that triangular recesses are arranged offset relative to one another on the upper side and the lower side. In the embodiment shown in FIG. 8, the annular element 14 is made of polyurethane. Instead of a compact polyurethane body in the form of a hollow cylinder or ring, of course, in other embodiments, a polyurethane body with recesses or cavities may be used. The annular element 14 is seated with the inner sleeve 13 on the bearing, however, in contrast to the example shown in Figure 7, the outer sleeve 15 is provided and in direct contact with the housing 1. In the in Figure 9 in a figure 7 corresponding side Sectional view shown embodiment, the ring ^¬ shaped member 14 is disposed of rubber between the inner sleeve 13 and the outer sleeve 15 and connected thereto, now has However, a so-called I-shaped profile, in which both not with the inner sleeve 13 and the outer sleeve 15 related sides have a circular recesses. Finally, Figure 10 shows several examples of useful profiles of the annular element 14. In order to realize greater spring travel, a ratio of loaded surfaces 7 to unloaded surfaces 8 is changed in favor of the unloaded surface. In Figure 10 a) a rectangular cross-section profile is shown with a centrally disposed cavity 16, while Figure 10 b) shows a pure rectangular profile. The loaded surfaces are in both embodiments shown on the top and bottom, while the sides represent unloaded surfaces 8. In the cavity 16 shown in FIG. 10 a), all sides defining this cavity 16 are unloaded surfaces 8. However, the annular element 14 can also have a parallelogram-like profile shown in FIG. 10 c) or can be trapezoidal, as shown in FIG. 10 d) , In these two exemplary embodiments, too, the loaded surfaces 7 are located on the upper side and the lower side, while the sides represent unloaded surfaces 8. Thus, in contrast to FIG. 10b), the sum of the loaded surfaces is reduced in FIG. 10d) and the sum of the unloaded surfaces is increased.

Finally, a T-shaped profile shown in FIG. 10 e) or an I-profile (FIG. 10 f)) also has symmetrical recesses on each side, which is not in contact with the outer sleeve 15 and / or the inner sleeve 13 Question. As in the previously described embodiments, the loaded surfaces 7 are again given by the top and bottom, while on the sides only unloaded surfaces 8 are present. By profiling these unloaded surfaces 8 are enlarged compared to a pure rectangular profile. Also, an H-profile, as shown in Figure 10 g), in which a recess is disposed both on the top and the bottom, or the U-profile shown in Figure 10 h) with a recess only on the top can be used. The now provided with a profile tops and bottoms are in turn loaded surfaces 7, while the side walls of the profiling in the top and the bottom are unloaded surfaces. In these examples, the sum of the loaded surfaces is reduced and at the same time increases the sum of the unloaded surfaces and thus influenced the mechanical properties of the floating bearing bush 10 with respect to the spring force and the spring travel.

The described bearing arrangement is used for example in a hybrid drive of a passenger vehicle.

Only features disclosed in the embodiments of the various embodiments can be combined and claimed individually.

Claims

claims

1. Bearing arrangement in a housing (1) for supporting a shaft (4) in a first bearing with a first bearing (2) (fixed bearing) and in an axially spaced from the first bearing second bearing with a second bearing (3) (movable bearing ), wherein the second bearing (3) in a floating bearing bush (10) is inserted, with an on the second bearing (3) arranged inner sleeve (13) and the inner sleeve (13) enclosing and connected annular element (14) of a elastic material is formed,

characterized in that

the annular element (14) on at least one outer upper ^¬ surface and / or in its interior, has a profiling.

2. Bearing arrangement according to claim 1, characterized in that the annular element (14) on at least two opposite outer sides profiling.

3. Bearing arrangement according to claim 1 or claim 2, characterized in that the elastic material of the annular element (14) has the profiling in its internal structure.

4. Bearing arrangement according to one of the preceding claims, characterized in that the annular element (14) made of an elastomer, preferably made of rubber or a

Polyurethane foam is formed.

5. Bearing arrangement according to one of the preceding claims, characterized in that the profiling is realized by at least one recess (16) on an outer surface and / or at least one arranged in the interior of the annular member hollow chamber (17).

6. Bearing arrangement according to one of the preceding claims, characterized in that an outer sleeve (15) is present, which surrounds the annular element (14).

7. Bearing arrangement according to claim 6, characterized in that a thermal expansion coefficient of a material of the outer sleeve (15) is at most 5 percent greater or smaller than a thermal expansion coefficient of a material of the housing (1).

8. Bearing arrangement according to one of the preceding claims, characterized in that the inner sleeve (13) and the annular element (14) are positively and / or materially connected, preferably connected to each other by gluing or by vulcanization.

9. Bearing arrangement according to one of the preceding claims, characterized in that the floating bearing bush (10) is biased in the bearing assembly to between one to four

Percent, preferably by between one and two percent of a dynamic Lagertragzahl the floating bearing.

10. Electrical machine with a bearing arrangement according to one of the preceding claims.