DE102006057874B4 - Hollow roller of a cylindrical roller bearing, method for producing such a hollow roller - Google Patents

Abstract

Hollow roller (1) for a cylindrical roller bearing with outer ring and inner ring, between which rolling elements designed as rollers are arranged, of which at least one roller is formed as a hollow roller (1), which consists of at least two coaxially pressed into each other tubes, wherein an inner circumferential surface (5 ) of a radially outer tube over its entire surface on an outer circumferential surface (4) of a radially inner tube, and in which a radially inner tube has a bore (7), characterized in that the radially inner tube is an excess relative to the radially inner diameter of the radial has the following conditions for the diameters of the individual tubes with respect to the outer diameter DW, the joint diameter DF and the inner diameter DWi of the finished hollow roll (1): the diameter ratio Qi = DWi / DW of the hollow roll (1 ) is greater than or equal to 0.5 and less than or equal to 0.8; the diameter ratio Qii = DWi / DF of the inner tube is greater than or equal to 0.5 and less than or equal to 0.9; the diameter ratio Qai = DF / DW of the outer tube is greater than or equal to 0.6 and less than or equal to 0.95.

Description

Field of the invention

The invention relates to a hollow roller for a cylindrical roller bearing with outer ring and inner ring, between which rolling elements designed as rolling elements are arranged, of which at least one roller is designed as a hollow roller, which consists of at least two coaxially pressed into each other tubes, wherein an inner circumferential surface of a radially outer tube full contact with an outer circumferential surface of a radially inner tube, and in which a radially inner tube has a bore.

Furthermore, the invention relates to a method for producing such a hollow roller.

Background of the invention

In cylindrical roller bearings and in other roller bearings, the load transfer is principally effected by rolling elements, in the case of cylindrical roller bearings by cylindrical rollers. For linear or rotary motion of the cylindrical roller bearing and the rolling elements must be moved. This movement takes place, for example, in linear guides with half the speed of the two cylindrical roller bearing parts, which usually consist of carriage and rail in linear bearings.

The energy required for this movement is generally transmitted by frictional forces. For this purpose, appropriate normal forces between the rolling elements and the raceway are required. If the normal forces are too low, slip occurs between the treads. Such slip conditions cause the rollers no longer rotate with their kinematic speed around their own axis and the rolling element no longer moves kinematically.

To avoid Wälzkörper- or Wälzkörpersatzschlupf, it is known a negative operating clearance, ie a. Preload, to use. This is often the case with tapered bearings, but is rarely used in needle, cylindrical roller and spherical roller bearings, as this leads to other disadvantages, such as increased friction. To avoid the Wälzkörpersatzschlupf, even larger individual rolling elements were installed in Wälzkörpersatz.

For example, in the DE 197 34 980 A1 a gear change proposed, with at least one cylindrical roller bearing mounted on a gear shaft gear, which is coupled via a coupling element with the transmission shaft, wherein radially between a transmission shaft associated inner race and a hub of the gear wheel associated outer race cylindrical hollow rollers are arranged in a cylindrical roller bearing cage. At least one hollow roller is elastically deformable radially biased, wherein its diameter is greater than the diameter of the remaining cylindrical rolling elements.

The one-piece hollow roller can consist of a plastic, of a thin-walled hollow steel body or of a spiral or helically wound spring steel. Hollow rollers have the disadvantage that in the region of the bore a bending-tension alternating voltage occurs, which is unfavorable in the rolling elements commonly used. On the other hand, hollow rollers also have principal advantages. They are characterized by a low weight, are flexible and well compressible, which in particular in the US Pat. No. 3,930,693 is emphasized, which also relates to one-piece hollow rollers.

There have also been described multi-part hollow rollers and rollers with concentric individual components. So revealed the DE 566 062 A a role for roller bearings, which for the purpose of limiting a particular of the centering holes of the role outgoing crack propagation consists of a core and one or more mechanically firmly joined shell layers. The purpose of such an embodiment is that crack formation during clamping of the blank for the purpose of material processing is avoided.

From the US 642,204A In addition, a hollow roller of a cylindrical roller bearing is known, in which a hollow liner (lining) made of pressed fibers is introduced into a hollow roller, which encloses the bore and serves the durability of a guided through the bore pin or bolt, which in direct contact with the coating is to increase.

From the DE 101 49 833 B4 is known a hollow roller, which according to the local 4 is made of two coaxially arranged and radially spaced pipe sections, wherein ends of an outer pipe section are deformed by rotational deformation such that they come to rest on the radially inner pipe section. As a result, a cylindrical annular cavity is created in the roller, wherein through the radially inner pipe section in the rolling body a hole open on both sides is formed which is separated from the cylinder-shaped cavity by the component wall of the radially inner pipe section. With such a configured hollow role a rolling element with low weight but the same stability of a solid body should be realized, so that such configured hollow role for setting a bias is not suitable.

Finally, that describes DE 39 19 199 A1 a method for producing a hollow roller having the features of the preamble of claim 1. A with respect to the local there 2 described hollow shaft consists of three coaxially pressed tubes in which an inner circumferential surface of a radially outer tube over the entire surface of an outer surface of a radially inner tube rests, wherein a radially inner tube forms a bore open on both sides, which serves to guide a cage bolt. The hollow roller described there is except for the bore, which has a small diameter, held quite solid. The adjustment of a bias by the design of the hollow role plays no role in this document.

A disadvantage of previously known hollow rollers, which are used in cylindrical roller bearings to produce or adjust a bias, is the difficulty with which the bias can be adjusted. Furthermore, the durability of such known hollow rollers leaves something to be desired in operation, since internal stresses or bending-tension alternating voltages often lead to premature failure of these hollow rollers.

Object of the invention

The invention has for its object to provide a hollow roller, which does not have the disadvantage of high bending tension alternating voltages, and allows a bias in Wälzkörpersatz in a simple constructive manner. Furthermore, a further object is to improve the (long) durability, in particular the durability, of such a hollow roller and to allow easy adjustment of a desired bias.

Summary of the invention

The invention is based on the finding that the stated object can be achieved in that the hollow roller consists of nested tubes, wherein at least one inner tube has an oversize prior to assembly, so that by the connection, a voltage is generated on the outer tube , In addition, it has been shown that the stated object can be achieved by the fact that the inner tube and the outer tube have certain diameter ratios.

The invention is therefore based on a hollow roller for a cylindrical roller bearing with outer ring and inner ring, between which rolling elements designed as rollers are arranged, of which at least one roller is formed as a hollow roller, which consists of at least two coaxially pressed into each other tubes, wherein an inner circumferential surface of a radially outer tube is fully applied to an outer circumferential surface of a radially inner tube, and in which a radially inner tube has a bore.

In addition, it is provided in this hollow roller, that the radially inner tube has an excess, in particular from 0.1% to 15%, compared to the radially inner diameter of the radially outer tube, and that for the diameter of the individual tubes with respect to the outer diameter D. _W , the joint diameter D _F and on the inner diameter D _{Wi of} the finished hollow roll the following conditions apply:
The diameter ratio Q _i = D _Wi / D _{W of} the hollow roller is greater than or equal to 0.5 and less than or equal to 0.8.

The diameter ratio Q _ii = D _Wi / D _{F of} the inner tube is greater than or equal to 0.5 and less than or equal to 0.9.

The diameter ratio Q _ai = D _F / D _{W of} the outer tube is greater than or equal to 0.6 and less than or equal to 0.95.

With these features, a hollow roll is advantageously created, are significantly reduced in the bending-tensile alternating stresses in the region of the inner diameter of the hollow roller during circulation of the hollow roller in the cylindrical roller bearing. As a result, it is now possible to execute not only individual but all rolling elements of the cylindrical roller bearing as hollow rollers. In addition, it has been found in studies compared to conventional hollow rollers that results in a 30% to 50% longer life of the hollow roller.

In addition, it may be provided that the diameter ratio Q _{i of} the hollow roller is 0.725, that the diameter ratio Q _{ii of} the inner tube is 0.806, and that the diameter ratio Q _{ai of} the outer tube is 0.900. These values have been found in experiments to be particularly favorable.

Furthermore, in this hollow roller can also be provided that the radially inner tube has an excess in a range of 0.1% to 15% relative to the radially inner diameter of the radially outer tube.

In another practical development can be provided that the hollow roller consists of two to five nested tubes. A further embodiment of the invention provides that the nested tubes of a hollow roller have the same axial lengths. It is also within the scope of the invention to provide that a pipe has a shorter axial length than another tube.

In a particularly practical embodiment of the invention, it is provided that the radially outer tube has a radially inner circumferential surface, which has a conical shape, and that the radially inner tube has a radially outer surface, which also has a conical geometry, wherein the two conical Lateral surfaces are employed against each other.

Also particularly advantageous is an embodiment of the invention, which is characterized in that the tubes consist of the same or different materials. It is preferred that at least one tube consists of a bearing steel, for example, a 100Cr6 steel.

Finally, an embodiment of the invention is particularly advantageous, which is characterized in that the inner tube is made of aluminum, sintered material, a low alloy steel or an alloy with memory effect.

Furthermore, it is particularly advantageous if at least two of the tubes are connected to one another via an adhesive or solder joint.

It may also be particularly preferred in a development that at least one of the joining surfaces is provided with a coating which is particularly suitable for preventing fretting corrosion and / or changing the coefficient of friction in the joining surfaces.

Finally, a refinement of the invention is advantageous, in which at least between two of the tubes a micro positive connection, in particular by knurling, is produced.

In the method according to the invention for producing a hollow roller as described, it is provided that the inner tube is widened in a partially plastic manner only after the joining, so that a permanent surface pressure is created in a joint between the inner tube and the outer tube.

Brief description of the drawings

The invention will be explained in more detail below with reference to the accompanying drawings. It shows

1 a cross section through a first embodiment of a hollow roller according to the invention,

2 a longitudinal section through the hollow roller according to 1 .

3 a cross section through a second embodiment of a hollow roller according to the invention,

4 a longitudinal section through the hollow roller according to 3 , and

5 a longitudinal section through a third embodiment of a hollow roller according to the invention.

Detailed description of the drawing

In the 1 and 2 is a first embodiment of a hollow roller according to the invention 1 shown in cross section and in longitudinal section. The hollow roller 1 serves as a rolling element of a cylindrical roller bearing, not shown, with outer ring and inner ring, between which rolling elements designed as rollers are arranged, of which at least one roller as a hollow roller 1 is trained. The hollow roller 1 can have a larger or equal diameter compared to the other, massive roles.

The hollow roller 1 according to the 1 and 2 consists of two coaxially pressed tubes 2 and 3 , wherein the radially inner tube 3 coaxial with the radially outer tube 2 is pressed. The radially outer surface 4 of the radially inner tube 3 lies completely on the radially inner circumferential surface 5 of the radially outer tube 2 at. The radially inner lateral surface 6 of the radially inner tube 3 forms a hole 7 while the radially outer surface 8th of the radially outer tube 3 the outer surface of the hollow roller 1 and thus forms the outer diameter.

The diameter of the radially inner circumferential surface 6 of the radially inner tube 3 is indicated by D _Wi , the diameter at the joint between the radially outer surface 4 of the radially inner tube 3 and the radially inner circumferential surface 5 of the radially outer tube 2 with D _F , and the diameter of the hollow roller 1 or the radially outer lateral surface 8th of the radially outer tube with D _W. The radius of the radially outer circumferential surface 8th of the radially outer tube 2 is with r _a , the radius to the joint with r _F and the radius of the inner diameter of the hollow roller is denoted by r _i .

In the illustrated embodiment, the diameters D _W = 50.8 mm, D _Wi = 36.8 mm and D _F = 45.7 mm. This results in the following diameter ratios Q:
The diameter ratio Q _{i of} the hollow roller 1 D _Wi / D _W = 0.725.

The diameter ratio Q _{ii of} the inner tube 3 is D _Wi / D _F = 0.806.

The diameter ratio Q _{ai of} the outer tube 2 is D _F / D _W = 0.900.

The axial length of the hollow roller 1 is 104 mm in the illustrated embodiment.

In comparative tests with a conventional, integral hollow roller with identical length and identical outer diameter, an inner diameter D _Wi of 40.6 mm and a diameter ratio Q _i of 0.80, it has surprisingly been found that the comparison stresses of the inventively designed hollow roller 1 was 30% higher compared to the conventional one-piece hollow roller. Compared to the one-piece hollow roller, the bias could be adjusted much better and more precise, in particular by the excess of the inner tube 3 ,

The outer diameter of the inner tube 3 is in fact before pressing into the outer tube 3 0.1 to 15% larger than after pressing. The inner tube is thus with a defined excess in the outer tube 2 pressed. This will target a bias in the outer tube 2 generated, thereby simultaneously disadvantageous alternating bending stresses during operation in the hollow roller 1 be reduced. Furthermore, it is thereby possible, the bending-tension AC voltage at the inner diameter of the hollow roller 1 during circulation of the hollow roller 1 to avoid or at least reduce.

As material for the outer tube 2 and for the inner tube 3 each grade 100Cr6 steel was used. However, it is also within the scope of the invention, for the inner tube 3 to use another material, such as a low alloy steel, aluminum or an alloy with a memory effect.

It is also possible to use the inner tube 3 made of a material with a relation to the material of the outer tube 2 produce lower or higher coefficients of expansion. It can thereby be achieved that the introduced in the finished hollow roll bias is set lower or higher at low temperatures.

In the 3 and 4 is a second embodiment of a hollow roller according to the invention 1 shown in cross section and in longitudinal section. The hollow roller 1 According to these figures also consists of two coaxially pressed into each other tubes 2 and 3 , wherein the radially inner tube 3 coaxial with the radially outer tube 2 is pressed. The radially outer surface 4 of the radially inner tube 3 lies completely on the radially inner circumferential surface 5 of the radially outer tube 2 at. The radially outer surface 8th of the radially outer tube 3 forms the outer surface of the hollow roller 1 and thus the outside diameter.

Unlike in the 1 and 2 variant shown has the hollow roller 1 according to the 3 and 4 another third pipe 9 on, which with its radially inner lateral surface 10 the hole 7 forms, while the radially outer circumferential surface 11 this tube 9 on the radially inner circumferential surface 6 of the inner tube 3 is applied. The two inner tubes 3 and 9 are in a process each with a defined excess in the outer tube 2 been pressed. The axial length of the inner or middle tube 3 deviates from the axial lengths of the radially inner tube 9 and the outer tube 2 from. While the outer tube 2 and the radially inner tube 9 have equal lengths is the tube 3 shorter than the other two tubes 2 and 9 , However, it is within the scope of the invention, including the radially inner tube 9 with one from the radially outer tube 2 and / or with one of the radial tube 3 form a different length.

By doing that the three tubes 2 . 3 and 9 have different axial lengths, is the suspension behavior of the hollow roller 1 positively influenced over the axial length transversely to the raceway of the rolling bearing. Such a hollow role 1 coming from the cylindrical nested pipes 2 . 3 and 9 manufactured, can behave like a profiled role. The different lengths of inner tubes 2 and 9 also serve for targeted adjustment of the preload in the assembled hollow roll 1 ,

In 5 is a third embodiment of a hollow roller according to the invention 1 shown in longitudinal section, in which the shape of the nested tubes 2 and 3 not cylindrical, but each one-sided tapered. Therefore, the radially outer tube 2 a thick-walled front edge 12 and an opposite thin-walled end edge 13 on, so that's the radially inner surface 5 of the radially outer tube 2 extends in an angle deviating from 90 °, in the illustrated embodiment at an angle of 86 °.

Accordingly, the radially inner tube 3 also a thin-walled front edge 14 and opposite a thick-walled end edge 15 on, so that's the radially outer surface 4 of the radially inner tube 3 in an angle deviating from 90 °, wherein the conical lateral surfaces 4 and 5 the pipes 2 and 3 are employed against each other.

When joining the two tubes creates a press fit of the two tubes 2 and 3 , which leads to a particularly durable composite. Furthermore, it has been shown that it is due to the conical design of the two tubes 2 . 3 It is particularly easy to set the roller outside diameter.

In addition, also the joining of the hollow roller 1 be carried out after the bearing assembly, so that only then creates the bias in the camp. The bearing can then be mounted like a bearing without preload.

In deviation to the in 5 illustrated embodiment, it is also possible, the conical inner tube 3 shorter than the tapered outer tube 2 form, which for a particularly simple assembly of such a configured hollow roller 1 leads.

LIST OF REFERENCE NUMBERS

1

hollow roller

2

Outer tube

3

Inner tube

4

Outer lateral surface of the inner tube 3

5

Inner lateral surface of the outer tube 2

6

Inner surface of the inner tube 3

7

drilling

8th

Outer lateral surface of the outer tube 2

9

Inner tube

10

Inner surface of the pipe 9

11

Outer lateral surface of the tube 9

12

front edge

13

front edge

14

front edge

15

front edge

Claims (13)

Hollow roller ( 1 ) for a cylindrical roller bearing with outer ring and inner ring, between which rolling elements designed as rollers are arranged, of which at least one roller as a hollow roller ( 1 ) is formed, which consists of at least two coaxially pressed into each other tubes, wherein an inner circumferential surface ( 5 ) of a radially outer tube over its entire surface on an outer circumferential surface ( 4 ) abuts a radially inner tube, and in which a radially inner tube has a bore ( 7 ), characterized in that the radially inner tube has an oversize relative to the radially inner diameter of the radially outer tube, and that for the diameter of the individual tubes with respect to the outer diameter D _W , the joint diameter D _F and the inner diameter D _Wi the finished hollow roller ( 1 ) the following conditions apply: the diameter ratio Q _i = D _Wi / D _{W of} the hollow roller ( 1 ) is greater than or equal to 0.5 and less than or equal to 0.8; the diameter ratio Q _ii = D _Wi / D _{F of} the inner tube is greater than or equal to 0.5 and less than or equal to 0.9; the diameter ratio Q _ai = D _F / D _{W of} the outer tube is greater than or equal to 0.6 and less than or equal to 0.95. Hollow roller according to claim 1, characterized in that the diameter ratio Q _{i of} the hollow roller ( 1 ) has a value of 0.725, that the diameter ratio Q _{ii of} the inner tube is 0.806, and that the diameter ratio Q _{ai of} the outer tube ( 2 ) has a value of 0.9. Hollow roller according to claim 1 or 2, characterized in that the hollow roller ( 1 ) consists of two to five nested tubes. Hollow roller according to at least one of claims 1 to 3, characterized in that the tubes have the same axial lengths. Hollow roller according to at least one of claims 1 to 3, characterized in that a tube has a shorter axial length than another tube. Hollow roller according to at least one of claims 1, 3 to 5, characterized in that the radially outer tube has a radially inner surface ( 5 ) having a conical geometry, and that the radially inner tube has a radially outer surface ( 4 ) has a conical geometry, wherein the two conical lateral surfaces ( 4 . 5 ) are employed against each other. Hollow roller according to at least one of claims 1 to 6, characterized in that the tubes consist of the same or different materials. Hollow roller according to claim 7, characterized in that at least one tube consists of a bearing steel, in particular of a 100Cr6 steel. Hollow roller according to at least claim 7, characterized in that the inner tube consists of aluminum, of sintered material, of a low alloy steel or of an alloy with memory effect. Hollow roller according to at least one of the preceding claims, characterized in that at least two of the tubes are connected to one another via an adhesive or solder joint. Hollow roller according to at least one of the preceding claims, characterized in that at least one of the joining surfaces is provided with a coating which is particularly suitable for preventing fretting corrosion and / or changing the coefficient of friction in the joining surfaces. Hollow roller according to at least one of the preceding claims, characterized in that at least between two of the tubes a micro positive connection, in particular by knurling, is made. Method in which the hollow roller is produced according to claim 1 to 12, wherein the inner tube is widened partially plastic after joining, so that in a joint between the inner tube and the outer tube, a permanent surface pressure arises.

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