DE102020106339A1 - Rolling bearing, with an inner ring, an outer ring and rolling elements accommodated in between - Google Patents

Abstract

Rolling bearing, with an inner ring (2), an outer ring (4) and rolling elements (7) accommodated in between, the outer ring (4) or the inner ring (2) being accommodated in a sleeve (12), with either one between the sleeve ( 12) and the outer ring (4) or inner ring (2) given radial annular space is injected with an electrically insulating insulating material (11) based on plastic, or the insulating material (11) as a coating either on the outer ring (4), the inner ring (2 ) or the sleeve (12) is applied, and either the sleeve (12) on the coated outer ring (4) or in the coated inner ring (2), or the outer ring (4) or the inner ring (2) in or on the coated Sleeve (12) is pressed on.

Description

The invention relates to a rolling bearing with an inner ring, an outer ring and rolling elements accommodated in between.

Rolling bearings of this type are used in a wide variety of applications where two components are to be mounted radially to one another so that they can be moved relative to one another. Just one example is the installation of such roller bearings in transmissions for mounting different transmission elements in both automatic and manual transmissions. Occasionally, such a roller bearing, beyond its actual bearing properties, is designed in such a way that it also offers a further function. For example, it's off DE 10 2013 224 538 A1 a roller bearing in the form of a roller sleeve is known, which has the task of reducing noise in addition to its actual radial bearing function. For this purpose, an outer sleeve enclosing the outer ring is provided on the roller bearing, which has no inner ring but only an outer ring, with an eccentric plastic ring being inserted between the outer ring and the outer roller sleeve. As a result, the center axes of the cylindrical outer ring and the cylindrical outer roller sleeve are not coaxial with one another, but rather are arranged parallel to one another. As a result of the eccentricity, a radial tensioning of the bearing is established when it is installed, resulting from a certain softness of the plastic material of the plastic sleeve, which prevents the generation of noise. Likewise, any noises that have arisen are effectively attenuated via the plastic sleeve in the sense of structure-borne noise. This means that there is an acoustic decoupling of the rotating parts from the stationary parts, by means of which decoupling mechanical damage to the area surrounding the roller sleeve can no longer occur, or particularly smooth rolling bearing operation is given. With this roller bearing, the focus is solely on the noise dampening via the eccentric plastic ring used, which is why such a bearing is intended for applications in which the aim is to improve driving comfort in motor vehicles, for example, by eliminating noise and / or vibrations from assemblies .

In addition, applications are known, for example in electrical machines, in which an electrical insulating plane is to be created between the components that are movably mounted relative to one another via the roller bearing, that is to say that the roller bearing is equipped with electrically insulating properties. This can be achieved, for example, by means of a so-called hybrid bearing, in which the rolling bearings are made of a ceramic, i.e. of an inherently electrically insulating material, or in which at least one of the raceways on which the rolling elements run, or the rolling elements with a ceramic or plastic coating. By appropriately designing the electrical insulation properties of the material of the insulating element or elements, adequate electrical insulation can be achieved via the roller bearing. In these applications, wear protection must also be taken into account to a great extent, especially when using such roller bearings in the form of floating bearings in electrical machines and the like, which is why the mechanical properties must also be designed accordingly. Because, on the one hand, the bearing must not show any radial relative mobility of the outer ring and inner ring to one another, as must a corresponding abrasion resistance, etc.

The design of previously known roller bearings having an electrical insulation level in the form of hybrid bearings or coated bearings is relatively complex in this context, which is why the bearings on the one hand can only be produced with greater effort and on the other hand are correspondingly expensive.

The invention is therefore based on the problem of specifying a roller bearing that is improved in comparison.

To solve this problem, the invention provides for a roller bearing of the type mentioned above that an outer ring or the inner ring is received in a sleeve, with either a radial annular space between the sleeve and the outer ring or the inner ring being injected with an electrically insulating plastic-based insulating material , or wherein the insulating material is applied as a coating either to the outer ring, the inner ring or the sleeve, and either the sleeve is pressed onto the coated outer ring or into the coated inner ring, or the outer ring or the inner ring is pressed into or onto the coated sleeve.

According to the invention, in the proposed bearing, the insulation level is moved radially outward or inward from the actual bearing area itself, i.e. the actual bearing unit consisting of the outer ring, inner ring and rolling elements is formed in the usual way from metal components without integrated isolation means. To implement the wear-protected insulation plane, a metal sleeve is provided which is either designed as an outer sleeve and consequently houses the outer ring at least radially, or which is designed as an inner sleeve and houses the inner circumference of the inner ring. According to the invention, the insulation plane is now provided between the radial jacket surface of the sleeve and the radial jacket surface of the adjacent outer or inner ring, which is formed via an electrically insulating plastic-based insulation material provided there.

Two different variants are provided with regard to the integration of this insulation level or the insulation material. Either the radial annular space resulting between the sleeve and the adjacent outer or inner ring can be injected with the insulating material. This means that the plastic material is introduced into the annular space in a sufficiently soft, injectable state, where it then hardens. Alternatively, one of the elements involved, i.e. either the sleeve or the outer or inner ring, can be coated with a coating of the insulating material on the corresponding outer surface, after which the elements are pressed onto one another or into one another and, in turn, the insulating material between the opposing outer surfaces of the Bearing elements is added.

The roller bearing according to the invention offers a number of advantages. On the one hand, the actual rolling elements, ie the outer ring, inner ring and rolling elements, are not involved in the realization of the insulation level, so they can be made of steel and can therefore be used in the form of conventional bearing components. The metal sleeve used, be it in the form of an outer sleeve or in the form of an inner sleeve, is a simple, preferably drawn component made of metal. This is therefore both simple to manufacture, the sleeve also offering corresponding mechanical parameters that represent the wear protection for the adjacent plastic insulation layer. The integration of the insulating layer or the insulating material is also simple, since after the assembly of the outer ring, inner ring and rolling elements, only the sleeve has to be joined, after which in one case only the insulating material has to be injected, which can be done using a suitable plastic injection device. In the other case, the insulating material is already in the form of a coating on the corresponding bearing element, so that the insulating plane is also integrated after joining and the corresponding press fit has been achieved.

The insulating material is selected in such a way that there is sufficient electrical insulating property. The insulation level should have a dielectric strength of ≥ 10 kV / mm. Also, since the rolling bearing according to the invention does not depend on noise damping, for which corresponding soft or elastic properties of the plastic material used are required, the insulating material is designed with sufficient mechanical properties so that there is no relative movements of the outer or inner ring relative to the assembly case outer sleeve comes, which is received in a suitable bearing seat, for example a housing bore or a bearing bracket or the like. The plastic material should preferably have a compressive strength of ≥ 150 N / mm ^{2 in} order to ensure the bearing load capacity or load-bearing capacity accordingly or to design the bearing accordingly. As in relation to the dielectric strength, the compressive strength can also be selected to be significantly greater than the specified minimum value.

It is expedient in a further embodiment of the invention if the sleeve has an L-shaped cross section and overlaps the outer or inner ring at one end face, the axial annular space between the sleeve and the outer or inner ring also being sprayed or coated with the insulating material. The sleeve is thus pot-shaped or L-shaped in cross section and also supports the outer or inner ring axially, the insulating material being provided in this area as well. Such a configuration is useful on the one hand as the bearing ring is axially supported. On the other hand, there is the possibility of axially supporting the sleeve if necessary or, as is sometimes the case with floating bearings such as those installed in electrical machines, of axially springing the sleeve via a spring element integrated on the bearing seat or the like.

If the insulating material, i.e. the insulating plastic, is injected, it is particularly useful if the material creates a material connection between the sleeve and the outer or inner ring, so that the outer or inner ring and the sleeve form an inseparable unit via the injected insulating material are connected. This embodiment of the invention offers the possibility of prefabricating this unit of outer or inner ring and sleeve before the actual rolling bearing assembly, i.e. before joining the rolling elements and the second ring, which has advantages in parts handling.

As described, the insulating material is a plastic material or a plastic-based material. A thermoplastic or a thermosetting plastic is preferably used for this purpose.

The sleeve, be it the outer sleeve or the inner sleeve, is made of metal, a steel sleeve also being expediently used here, for example made of a drawn steel sheet or the like.

In addition to the roller bearing itself, the invention also relates to a bearing arrangement comprising a roller bearing of the type described above, whose sleeve surrounding the outer ring is received in a bearing seat or whose sleeve surrounding the inner ring is received on a bearing seat. In the bearing arrangement according to the invention, the rolling bearing described above is on a corresponding one Bearing carrier, which has a bearing seat, arranged. Depending on whether the sleeve is an outer sleeve or an inner sleeve, the bearing seat is designed accordingly, since the sleeve, that is to say the steel sleeve surrounding the insulating layer, forms the interface with the bearing seat.

The bearing seat can either be a housing bore into which the roller bearing is inserted. In this case the sleeve is an outer sleeve. If the sleeve is an inner sleeve, the bearing seat is expediently a shaft on which the roller bearing is placed.

In addition to the arrangement of the roller bearing with its sleeve directly on these central components of the machine, for example the electric machine or the like, it is also conceivable to form the bearing seat for the sleeve, i.e. the steel sleeve housing the insulating plane, via an additional sleeve that either in the form of an outer sleeve, which receives the sleeve surrounding the outer ring, or in the form of an inner sleeve, which receives the sleeve surrounding the inner ring. Such an outer or inner sleeve, often also called “bushing”, is used, for example, in floating bearings in electrical machines or electric drives to compensate for the expansion coefficients. The sleeve prevents any influence of the expansion of the plastic material on the sliding seat, since the sleeve, that is to say the steel sleeve, restrains this expansion. Via this additional outer or inner sleeve, the bearing or the bearing arrangement can then be installed in the actual bearing seat, such as a housing bore, a bearing plate or a bearing bracket. This outer or inner sleeve then represents the assembly interface to the respective assembly environment.

If the sleeve surrounding the insulating plane is L-shaped in cross section, the radially extending sleeve leg can serve as a stop leg in the bearing seat, regardless of how it is designed. This means that the housing bore or, like the shaft, has a collar serving as an axial stop, or that the outer sleeve or the inner sleeve has an L-shaped cross section with a radially running radial collar. The sleeve leg is supported against the collar on the bore or shaft side. In the event that the bearing seat is formed by the outer or inner sleeve, this also has an L-shaped cross-section, corresponding to the sleeve of the roller bearing, with a radially running radial collar on which the corresponding, radially extending flange of the sleeve, i.e. the sleeve-side radial collar is axially supported.

This configuration also offers the advantage of providing a spring element which springs axially the roller bearing and which is positioned either between the collar of the housing bore or the radial collar of the outer or inner sleeve and the end face of the adjacent outer ring, or between the collar of the housing bore or the radial collar of the outer or inner sleeve and the radial collar of the sleeve is arranged. Via this spring element, which is used, for example, in the case of floating bearings in electrical machines, for axially springing the floating bearing in order to improve the noise behavior of the bearing arrangement, the roller bearing is consequently axially preloaded.

The outer or inner sleeve itself is also made of metal, preferably steel, but the use of aluminum is also conceivable.

• 1 eine Prinzipdarstellung eines erfindungsgemäßen Wälzlagers einer ersten Ausführungsform,
• 2 eine Prinzipdarstellung eines erfindungsgemäßen Wälzlagers einer zweiten Ausführungsform, und
• 3 eine Prinzipdarstellung einer erfindungsgemäßen Lageranordnung.

The invention is explained below on the basis of exemplary embodiments with reference to the drawings. The drawings are schematic representations and show:

• 1 a schematic diagram of a roller bearing according to the invention of a first embodiment,
• 2 a schematic diagram of a roller bearing according to the invention of a second embodiment, and
• 3 a schematic diagram of a bearing arrangement according to the invention.

1 shows a roller bearing according to the invention 1 in the form of a deep groove ball bearing, as it can be used, for example, as a floating bearing in an electric machine. The roller bearing 1 includes an inner ring 2 with an inner ring raceway 3 , an outer ring 4th with an outer ring raceway 5 as well as a plurality of in a cage 6th recorded rolling elements 7th in the form of balls that run on the raceways 3 , 5 roll over. The inner ring 2 , the outer ring 4th as well as the rolling elements 7th are accordingly made of steel, depending on the storage properties to be achieved.

On the outer ring 4th is, its outer circumferential surface 8th as well as its face 9 covering, an insulation layer 10 made of an electrically insulating insulating material 11 applied on a plastic basis. The insulating material 11 is preferably a thermoplastic or a thermosetting plastic. The insulation layer 10 is in turn of a sleeve 12th surrounded, which is L-shaped in cross section and a cylindrical sleeve portion 13th and a radially inward radial collar 14th having. With their inner surface 15th lies the sleeve 12th on the insulation layer 10 at. About the insulation layer 10 an insulating layer is formed, that is, the outer ring 4th and the sleeve 12th are electrically isolated from each other. The sleeve 12th is received in the assembly position in a corresponding bearing seat, for example a housing bore or the like.

The insulation layer 10 is preferably formed in that after joining the sleeve 12th an annular gap between the inner surface 15th the sleeve 12th and the radial lateral surface 8th as well as the axial face 9 results. This annular gap is with the insulating material 11 hosed out. The insulating material 11 a material bond with the respective surfaces is formed, so that the sleeve 12th and the outer ring 4th form an inseparable unit. Alternatively, it is also conceivable to use the insulation layer 10 either on the outside of the outer ring 4th or on the inside of the sleeve 12th to be applied as a coating and then the outer ring 4th and the sleeve 12th to join, so to press into each other, so that there is a corresponding press fit.

The insulation layer 10 has adequate electrical insulating properties, in particular a correspondingly high dielectric strength, which should preferably be ≥ 150 kV / mm. It also has corresponding mechanical parameters, in particular a high compressive strength, since any relative movements of the sleeve 12th to the outer ring 4th should be prevented in the assembly position. The sleeve 12th , which is made of metal, preferably a steel sleeve, protects the insulating material 11 against wear due to any relative movements of the roller bearing 1 to the bearing seat after the sleeve 12th represents the actual assembly interface to the bearing seat or to the assembly environment. Due to the firm connection of the sleeve 12th to the insulation layer 10 and their fixed connection to the outer ring 4th ties the case 12th any expansion of the insulating material 11 .

2 shows a second embodiment of the invention of a rolling bearing 1 , the same reference numerals being used for the same components. An inner ring is again provided 2 , an outer ring 4th as well as in a cage 6th guided rolling elements 7th who are on the appropriate careers 3 , 5 roll over. In this embodiment there is again a sleeve 12th provided over an electrical insulation layer 10 made of an insulating material 11 here from the inner ring 2 is electrically isolated. That is, the sleeve 12th with their cylinder section 13th along the inner circumference 16 of the inner ring 2 runs and with the radial collar 14th the axial face 17th of the inner ring engages over, the resulting annular space with the insulation material 11 is filled out. Either is the insulation material here too 11 injected, or as a coating prior to press joining the sleeve 12th and inner ring 2 applied to one of the parts.

Finally shows 3 a bearing arrangement according to the invention 18th as it can be used, for example, as a floating bearing in an electric machine. The bearing arrangement 18th comprises a roller bearing according to the invention 1 , with inner ring 2 , Outer ring 4th and rolling elements 7th , being here, accordingly 1 , the insulation layer 10 and the sleeve 12th on the outer ring 4th are arranged.

The bearing arrangement 18th further comprises a bearing seat 19th , here by a sleeve designed as an outer sleeve 20th is formed which is L-shaped in cross section and has a cylindrical portion 21 as well as a radial collar 22nd having. In this sleeve 20th that is made of aluminum or steel, but in any case made of metal, is the rolling bearing 1 pushed in or pressed in, that is, the sleeve 12th is in the sleeve 20th used. Between the two radial collars 14th and 22nd is a spring element 23 used in the form of an annular spring over which the roller bearing 1 is axially sprung. This serves to improve the noise behavior in the assembly application. The sleeve 20th , which can serve to compensate for different expansion coefficients, in this case serves as a mounting interface to the mounting environment, which can be a housing bore into which the bearing arrangement 18th respectively the sleeve 20th is used, but it can also be a recording in a bearing bracket or a bearing plate.

Although 3 a roller bearing 1 according to 1 with a sleeve designed as an outer sleeve 20th shows, it is of course also conceivable, the roller bearing 1 the end 2 with a corresponding sleeve, then designed as an inner sleeve 20th to be provided, with a spring element if necessary in this case as well 23 can be integrated.

List of reference symbols

1

roller bearing

2

Inner ring

3

Inner ring raceway

4th

Outer ring

5

Outer ring raceway

6th

Cage

7th

Rolling elements

8th

Outer jacket surface

9

Face

10

Insulation layer

11

insulating material

12th

Sleeve

13th

Sleeve section

14th

Radial collar

15th

Inner surface

16

Inner circumference

17th

Face

18th

Bearing arrangement

19th

Bearing seat

20th

Sleeve

21

section

22nd

Radial collar

23

Spring element

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102013224538 A1 [0002]

Claims (10)

Rolling bearing, with an inner ring (2), an outer ring (4) and rolling elements (7) received in between, characterized in that the outer ring (4) or the inner ring (2) is received in a sleeve (12), with either one between the sleeve (12) and the outer ring (4) or inner ring (2) given radial annular space is injected with an electrically insulating insulating material (11) based on plastic, or the insulating material (11) as a coating either on the outer ring (4), the Inner ring (2) or the sleeve (12) is applied, and either the sleeve (12) on the coated outer ring (4) or in the coated inner ring (2), or the outer ring (4) or the inner ring (2) in or is pressed onto the coated sleeve (12). Roller bearings after Claim 1 , characterized in that the sleeve (12) has an L-shaped cross section and overlaps the outer ring (4) or inner ring (2) at one end face (9, 17), the one between the sleeve (12) and the outer ring ( 4) or the inner ring (2) given axial annular space is sprayed or coated with the insulating material (11). Roller bearings after Claim 1 or 2 , characterized in that the outer ring (4) or the inner ring (2) and the sleeve (12) are connected to a non-separable unit via the injected insulating material (11). Rolling bearing according to one of the preceding claims, characterized in that the insulating material (11) is a thermoplastic or a duroplastic. Rolling bearing according to one of the preceding claims, characterized in that the sleeve (12) is a steel sleeve. Bearing arrangement comprising a roller bearing (1) according to one of the preceding claims, whose sleeve (12) surrounding the outer ring (4) is received in a bearing seat or whose sleeve (12) surrounding the inner ring (2) is received on a bearing seat. Bearing arrangement according to Claim 6 , characterized in that the bearing seat is either a housing bore into which the rolling bearing (1) is inserted, or a shaft on which the rolling bearing (1) is placed, or that the bearing seat is an outer sleeve (20) that supports the The sleeve (12) surrounding the outer ring (4) receives, or an inner sleeve (20) which receives the sleeve (12) surrounding the inner ring (2). Bearing arrangement according to Claim 7 , characterized in that the housing bore or the shaft has a collar serving as an axial stop, or that the outer sleeve (20) or the inner sleeve (20) has an L-shaped cross section with a radially running radial collar (22). Bearing arrangement according to Claim 8 , characterized in that the roller bearing (1) axially resilient spring element (23) is provided, which either between the collar of the housing bore or the radial collar (22) of the outer or inner sleeve (20) and the end face (9) of the adjacent outer - Or inner ring (4, 2), or between the collar of the housing bore or the radial collar (22) of the outer or inner sleeve (20) and the radial collar (14) of the sleeve (12). Bearing arrangement according to one of the Claims 6 until 8th , characterized in that the outer or inner sleeve (20) is made of steel or aluminum.

Images