DE102008050231A1 - Rolling body i.e. ball, for roller bearing, has cavity and two openings that lie opposite to each other, where body is in form of ball whose surface is flattened in region of openings - Google Patents

Abstract

The body (1) has a cavity and two openings that lie opposite to each other, where the body is in the form of a ball whose surface is flattened in a region of openings (2). The radius in the region of the opening is lesser than the radius of a vertical. Flattened sections of a surface of the body and a spherical section of the surface of the body pass into one another continuously. The body is manufactured by pressing under pressure, hot transforming under rotation, forging, pouring, sintering, extrusion molding, interior high pressure transforming, sheet-metal forming or by cutting. An independent claim is also included for a roller bearing comprising an outer ring.

Description

Field of the invention

The The invention relates to a rolling element, in particular for a rolling bearing, with a cavity and two Opposing openings.

Background of the invention

It has long been known to form rolling elements, for example, as hollow balls in order to achieve a weight reduction. In the DE 1 951 302 A the production of rolling bearing balls is described, which are composed of two hemispheres. However, their production is complex and it has been found in practice that the joining area has only a limited life.

As a hollow body formed rolling elements are also in the DE 2 407 479 A proposed. The rolling elements have a complicated inner contour, which requires complex manufacturing steps. In one variant, the hollow body is then provided with caps, which are strengthened by a welding process be. In the DE 2 407 479 A It has already been pointed out that the rolling elements align during operation in such a way that they rotate about their principal axis of inertia. This effect can be exploited by a corresponding mass distribution, which means that joining areas or the areas of the caps applied during operation experienced no high bearing loads.

In the GB 1 225 209 A a hollow rolling element is proposed which consists of two spherical shells, wherein the smaller shell is disposed within the larger shell.

A rolling bearing in which the rolling elements are designed as hollow bodies is known from US 3,574,425 known. There, however, the rolling elements require a cage that causes additional and undesirable bearing friction.

A composed of two half-shells rolling elements is in the US 3,559,307 described. In the region of the parting plane, the two hemispheres have complementary latching sections with which the two hemispheres can be latched together.

In the DE 2 200 103 a rolling bearing is described with trained as a hollow balls rolling elements, which are held by projections which engage laterally in openings of the hollow spheres. However, additional friction is generated by such projections.

In In practice, it has been found that in lightly loaded Rolling bearings slip of the rolling elements occur can. At higher speeds, the slip can be damaged the raceways of the inner ring and / or the outer ring of the Cause rolling bearing.

Object of the invention

Of the Invention is therefore based on the object, a rolling element specify with which the occurrence of slip in a rolling bearing even at higher speeds can be avoided.

Description of the invention

to Solution of this problem is in a rolling element of the type mentioned above provided according to the invention, that the rolling element is the basic shape of a sphere whose surface is in the region of the openings flattened.

Of the Invention is based on the finding that an undesirable high surface pressure in the area of the inner and / or outer ring a rolling bearing avoided by rolling elements can be whose surface in the area of the openings flattened. By this flattening or profiling it can not too high local surface pressures come when the opening area rolls over becomes. The flattening or profiling can be designed so that no adverse surface pressure occurs, so the running surfaces of the inner and / or outer ring not be damaged. In addition, leads the lower surface pressure also increased Life of the rolling elements.

at the rolling element according to the invention can the radius in the area of an opening is smaller than the radius a perpendicular to it. The vertical radius corresponds to this the radius of the solid sphere. Because the radius is in the range of an opening smaller than the radius in the vertical direction is to decrease when rolling over an opening, the local Surface pressures.

at the rolling element according to the invention is it is particularly preferred that the flattened portions of the surface of the rolling element and the spherical one Section of the surface of the rolling element continuously merge into each other. Through the continuous transition will be local voltage spikes and thus damage the storage areas avoided.

The rolling element according to the invention is preferably made of stainless steel, but depending on the particular application, other materials can be used. The rolling element, for example, by one of fol be made pressing process under pressure, hot forming under rotation, forging, casting, sintering, extrusion, hydroforming, sheet metal forming or by machining.

Besides the invention relates to a roller bearing, with an outer ring, an inner ring and arranged therebetween rolling elements, wherein at least one rolling element has a cavity and two opposing openings having.

The Inventive roller bearing is characterized characterized in that at least one rolling element the Basic shape of a sphere whose surface in the area the openings is flattened.

According to one preferred embodiment of the invention may be provided in that the rolling bearing has at least one cavity Has rolling elements and a plurality of massive rolling elements. Behave a rolling element having a cavity elastic, preventing slippage at higher speeds becomes.

It It is particularly preferred that the rolling elements having a cavity a larger outer diameter than the have massive rolling elements. This results the effect of a bias, causing slippage of the rolling elements is avoided in the rolling bearing.

at the rolling bearing according to the invention can the ratio of a cavity having rolling elements to the massive rolling elements 1: 6 to 1: 2 amount.

Short description of the drawing

A preferred embodiment of the invention formed Rolling elements will be referred to below explained in more detail in the accompanying drawings. Showing:

1 a first view of a rolling element according to the invention,

2 the rolling element of 1 in a view rotated by 90 °;

3 the rolling element of 2 in a sectional view; and

4 a section through a rolling bearing with rolling elements according to the invention.

Detailed description the drawing

The in 1 shown rolling elements 1 has the basic shape of a sphere whose surface is in the region of openings 2 flattened. In the side view of 1 is the circular peripheral contour of the rolling element 1 to recognize. The rolling element 1 is hollow, the cavity is with the opposite openings 2 connected.

2 shows the rolling element 1 in a 90 ° rotated view. In this view is visible that the rolling element 1 flattened sections on two opposite sides 3 . 4 that has the openings 2 surrounded by a ring. The radius R1 of the rolling element 1 along the opening 2 is smaller than the perpendicular radius R2. In the illustrated embodiment, the flattened portions go 3 . 4 the surface of the rolling element 1 and the spherical section 5 the surface of the rolling element 1 almost continuously into each other.

3 shows the rolling element of 2 in a cut view. The rolling element 1 has a nearly constant wall thickness, inside the rolling element 1 trained cavity 6 extends to the openings 2 , The dot-dashed horizontal line is both the axis of symmetry and the main axis of inertia of the rolling element 1 , During operation, the rolling element depends 1 so that a rotation around the main axis of inertia takes place.

In 4 is a rolling bearing 7 shown, consisting of an outer ring 8th , an inner ring 9 and arranged therebetween rolling elements. Some rolling elements 1 are hollow and correspond to the in the 1 to 3 shown rolling elements, the remaining rolling elements 10 are solid. The outer diameter of a cavity having rolling elements 1 is greater than the outer diameter of the solid rolling elements 10 whereby an elastic effect is achieved during operation and the occurrence of slippage is avoided.

When operating the rolling bearing 7 The rolling elements which have the cavity are aligned 1 around its main axis of inertia, so that a roll over the openings 2 the rolling elements 1 is avoided. If, nevertheless, during start-up or at low speeds, a rollover of the openings 2 occurs through the flattened sections 3 . 4 Damage to the raceways of the outer ring 8th and the inner ring 9 as well as the rolling elements 1 even avoided.

1

rolling elements

2

opening

3

flattened section

4

flattened section

5

spherical section

6

cavity

7

roller bearing

8th

outer ring

9

inner ring

10

rolling elements

R1

radius

R2

radius

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 1951302 A [0002]
• - DE 2407479 A [0003, 0003]
• - GB 1225209 A [0004]
• - US 3574425 [0005]
• US 3559307 [0006]
• - DE 2200103 [0007]

Claims (8)

Rolling elements, in particular for a roller bearing, having a cavity and two mutually opposite openings, characterized in that the rolling elements ( 1 ) has the basic shape of a sphere whose surface in the region of the openings ( 2 ) is flattened. Rolling element according to claim 1, characterized in that the radius (R1) in the region of an opening ( 2 ) is smaller than the radius (R2) of a perpendicular to it. Rolling element according to claim 1 or 2, characterized in that the flattened sections ( 3 . 4 ) of the surface of the rolling element ( 1 ) and the spherical section ( 5 ) of the surface of the rolling element ( 1 ) continuously merge. Rolling element according to one of the preceding claims, characterized in that it is characterized by at least one of the following Process is prepared: pressing under pressure, hot forming under rotation, forging, casting, sintering, extrusion, Hydroforming, sheet metal forming, machining. Rolling bearing having an outer ring, an inner ring and arranged therebetween rolling elements, wherein at least one rolling element has a cavity and two opposing openings, characterized in that at least one rolling element ( 1 ) has the basic shape of a sphere whose surface in the region of the openings ( 2 ) is flattened. Rolling bearing according to claim 5, characterized in that it has at least one cavity ( 6 ) having rolling elements ( 1 ) and several massive rolling elements ( 10 ) having. Rolling bearing according to claim 6, characterized in that the one cavity ( 6 ) having rolling elements ( 1 ) has a larger outer diameter than the solid rolling elements ( 10 ) exhibit. Rolling bearing according to claim 6 or 7, characterized in that the ratio of a cavity ( 6 ) having rolling elements ( 1 ) to the massive rolling elements ( 10 ) Is 1: 6 to 1: 2.