DE102008044799A1 - Rolling elements for a rolling bearing and roller bearings - Google Patents

Abstract

A roller body (2) for a roller bearing comprises a hollow roller (4) with a through bore (8) running along a rotation axis (A) of the hollow roller (4) and an inner body (6) arranged in the through hole (8). The inner body (6) serves as a support body in radial loads of the hollow roller (4). The inner body (6) has a cylindrical body (18) which lies with a radial clearance fit coaxially in the through hole (8). To improve the kinematics of the inner body (6), it is provided that the hollow roller (4) and the inner body (6) are designed for positive locking in the axial direction.

Description

Field of the invention

The The invention relates to a rolling element for a Rolling bearing comprising a hollow roller with a along a Rotation axis of the hollow roller extending through hole as well a cylindrical inner body having a radial Clearance is arranged coaxially in the through hole.

Background of the invention

rolling elements, the one through its axis of rotation extending through hole have, come z. B. then in bearings for use when the mass moment of inertia of the bearing set (rolling elements and cage) should be reduced.

A Hollow roller or a hollow cylinder as an example of such a rolling element, consisting of an open circular cylinder with a central bore, is also used in lightly loaded bearings to the To reduce the risk of slippage. This will be individual conventional massive rolling elements by hollow rollers with a slightly larger outer radius replaced. The outer radius of the hollow rollers is chosen so that these in the load-free state of the bearing a permanent Ensure contact with the raceways. The hollow rollers spring with increasing load of the bearing, so that from a certain load the massive rolling elements endorse.

In the US 3,620,585 a ball bearing is described which comprises a plurality of rolling elements, which are held by a cage. To reduce the weight of the rolling elements, these are made hollow by a through bore is formed by each rolling element. To position such a rolling element, a pin is performed through the bore, which is attached to both sides of the cage.

However, the formation of a rolling element in the manner of a hollow roller can also lead to problems. Thus, it was found that the hollow rollers represent potential weak points of the rolling bearing in terms of their load capacity and fatigue strength under a radial load. To solve this problem is in the application of the Applicant with the official file number of DPMA 10 2007 062 391.9 proposed to arrange an overload body with a radial clearance coaxially in the through hole of a hollow roller, which supports the hollow roller with radial load of the rolling element before a predetermined material stress of the hollow roller is exceeded.

Object of the invention

Of the Invention is based on the object, the kinematics of such Inner body or overload body in the Improve warehouse operations. The invention is still the task based, a rolling bearing comprising rolling elements specify with such an inner body.

Solution of the task

The The first object is achieved according to the invention by a rolling element for a rolling bearing, comprising a hollow roller with one along an axis of rotation the hollow roller extending through hole and a cylindrical Body coaxial with a radial clearance fit the through hole is arranged, wherein the hollow roller and the Inner body for a positive connection in the radial direction are formed. Under a cylindrical hull will not only a straight circular cylinder understood, but each rotationally symmetric Body with two parallel end faces, such. B. a barrel-shaped Hull.

The Invention is based on the consideration that an improvement the kinematics of the inner body when using the rolling bearing is achieved by an axial guidance of the inner body realized in the through hole by positive engagement with the hollow roller is. The positive connection is made by fitting the shape of the hollow roller and / or the inner body to each other, such that a axial displacement of the inner body in the through hole over a predetermined tolerance level is prevented. thanks the axial guidance of the inner body of the hollow roller over Positive locking takes place in particular no support of the inner body on Cage, allowing a friction reduction between the inner body and the cage and additional cage loads be avoided at high radial forces.

According to one preferred embodiment, the edge regions of the hollow roller and / or the inner body designed to form the positive connection. As a result, the use of the inner body as a support body allows, by inside the through hole space for a radial clearance fit between the inner body and the wall of the through hole is present and the positioning the inner body takes place only in the edge regions. With border area will continue in the registration area in the Near the end faces of the rolling element in which the geometry of the inner body and / or the hollow roller is modified to form the positive connection.

A particularly secure guidance of the inner body is made possible by, according to another preferred embodiment, the radius of the end face of the inner body is greater than the radius of the through hole. Thus, slippage of the inner body is prevented by the through hole, even if a clearance fit is set between the inner body and the hollow roller along the through hole.

In order to the inner body inserted into the through hole can be, even if the radius of his face bigger is considered the radius of the through hole, is at the fuselage at least on one side in the edge region preferably arranged an edge piece, by which the radius of the inner body in the direction of Front side rises and thus forms a raised edge. The Edge piece here represents a part made separately from the hull which is later firmly connected to the fuselage, to form the inner body. When assembling the Rolling is the hull in the through hole introduced and then the edge piece for forming the complete inner body with the fuselage firmly connected. The connection between the hull and the edge piece can be non-positive, positive or cohesive be, with no relative movement between the hull and the edge piece takes place. In the simplest case, the edge piece sets one Truncated cone with a continuous lateral surface is possible. Possible but also, on the lateral surface of the edge piece notches or recesses for other elements, such as. B. seals, provided. The edge piece can be made of the same material be formed as the inner body. In one embodiment with two such edge pieces, which are arranged on both sides of the fuselage In particular, these are made of a different material than the one used Hull formed, without affecting the stability of the Inner body is impaired.

In order to the inner body can be positioned in the through hole can at least one edge piece is required, which at the edge with the introduced in the through hole Hull is connected and thus slipping through the hull prevents the through-hole. In case of only one margin piece is provided for forming the inner body is preferably the hull is profiled in the other edge region of the inner body, so that the radius of the inner body towards the front rises and forms a raised edge. The profiled edge area of the inner body in this case has an identical in particular Structure to that of the edge piece. In addition, the edge piece in particular made of the same material as the hull of the inner body, so that in its assembled state the inner body has a symmetrical structure and is equally hard on both sides in the edge area.

A particularly good adaptation of the shape of the inner body to the Form of the hollow roller in the edge regions is present, preferably the hollow roller to the through hole rounded edges and the edge regions of the inner body from the outside considered concave, wherein a radius of curvature the concave edge areas a rounding radius of the rounded Corresponds to margins. Considered from the through hole Thus, the rounded edges of the hollow roller are convex formed and correspond with the concave edge areas. There is a particularly good marginal Anschmiegung of Inner body to the hollow roller.

alternative are the edge regions of the inner body from the outside Seen also convex and contact the rounded convex edges of the hollow roller. The through hole is thus viewed in a longitudinal section laterally through two convex surfaces (rounded edge of the hollow roller and edge area of the inner body) which touch each other. There is a linear contact between the inner body and the hollow roller around the circumference of the perforation, allowing a displacement of the inner body with respect to the Hollow roller is prevented.

The Edge regions of the inner body can also indirectly touching the rounded edges of the hollow roller, z. B. via a sealing element, which has a density function Fulfills. Therefore, it is preferably on the inner body a receptacle for a sealing element between the inner body and the hollow roller provided. The recording is for example after Formed a kind of circumferential groove, in which an O-ring inserted becomes. The sealing element also provide for a reservation of oil and for an extra Damping of radial shocks.

Conveniently, is the contact point between the sealing element and the hollow roller in Edge region of the hollow roller. This means that from the axis of rotation of the rolling body from the point of contact Seal is located on a larger radius than the Radius of the through hole.

Prefers is the edge piece around the circumference of the inner body arranged in a ring. This represents a particularly material-saving Embodiment in which the annular edge piece can be sized small. In this embodiment is in particular provided that the hull at its end recesses for receiving having the edge piece.

Alternatively, the edge piece is attached to the front side of the fuselage. This results in a large-area connection between the inner body and the Edge piece, which extends in particular over the entire front side of the fuselage.

advantageously, is the edge piece of a different material than the hull educated. Here are in particular two edge pieces provided, which are arranged symmetrically on both sides of the fuselage are. In particular, in an embodiment in which the edge piece immediately touches the hollow roller, the edge piece preferably formed of a more elastic material than the inner body, so that the edge piece abut well on the edge region of the hollow roller can.

The second object is achieved according to the invention by a rolling bearing comprising a plurality of rolling elements, wherein at least one of the rolling elements is a rolling element according to one of the preceding embodiments. Such a rolling bearing can z. B. used to the moment of inertia to reduce. In this case, preferably several, in particular all rolling elements formed according to one of the preceding embodiments.

Short description of the drawing

embodiments The invention will be described below with reference to a drawing explained. Herein schematically show:

1 in a combined front and sectional view, a hollow rolling element with an inner body with raised edge regions,

2 a first embodiment of the edge region of the rolling body,

3 a second embodiment of the edge region of the rolling body,

4 a third embodiment of the edge region of the rolling body, and

5 a fourth embodiment of the edge region of the rolling body.

In the figures are the same acting parts with the same reference numerals Mistake.

Detailed description the drawing

In 1 is a rolling element 2 a rolling bearing not shown here in detail, which is essentially a hollow roller 4 and one in the hollow roll 4 arranged support or inner body 6 includes. A rolling bearing with such rolling elements 2 can z. B. in wind power transmissions and paper machines. Due to its structure, which will be described in detail below, the rolling bearing is slip-free. The slack freedom refers to the rolling element slip and the rolling element slip. By the bias of the hollow roller 4 Relative movements are at the point of contact between the raceway and the rolling element 2 avoided, especially at high shaft and career accelerations.

The hollow roller 4 has a through bore extending along a rotation axis A. 8th on, with the inner body 6 with a radial clearance adjustment coaxial in the through hole 8th is arranged. Between the hollow roller end face and the front side 14 of the inner body 6 a gap S is formed. The gap S compensates for the axial displacement of the support body 6 relative to the hollow roller 4 such that the end faces of the two components (front side 14 of the inner body 6 and the hollow roller 4 ) have a maximum allowable distance from each other. Ideally, the support body stands 6 not laterally from the hollow roller 4 out. This is especially for the frontal approach with a cage pocket 15 relevant (see 2 and 3 ), ie, the gap S is dimensioned such that a lateral approach to the cage pocket 15 is avoided.

When positioning the support or inner body 6 is a gap provided in both the axial and in the radial direction, which is selected such that the inner body 6 in the through hole 8th is defined. How out 2 is apparent, is in the axial direction between the hollow roller 4 and the inner body 6 a game .DELTA.x provided, wherein in the illustrated embodiment, that S ~ .DELTA.x / 2. In the radial direction of the inner body 6 on the hollow roller 4 in subareas.

Thanks to their shape are the hollow role 4 and the inner body 6 designed for a positive connection in the axial direction. This is done via the design of the hollow roller 4 and the inner body 6 at the edge 10 , On one side has the hollow roller 4 for through-hole 8th convex rounded edges 12 on. On the other side, the inner body points 6 corresponding, concave, raised edges on, so that the radius of the inner body 6 towards the front side 14 rises to its maximum radius R _I. The radius R _{I is} the front side 14 of the inner body 6 greater than the radius R _{D of} the through hole 8th , With regard to a good fitting of the inner body 6 to the hollow roller 4 corresponds to the radius of curvature of the concave edge region 10 of the inner body 6 the rounding radius the rounded edge 12 the hollow roller 4 ,

As in particular from the enlargement in 2 it can be seen, the raised edges of a disc-like edge piece 16 formed with a conical, curved surface, wel on a cylindrical hull 18 of the inner body 6 is arranged.

In the embodiment shown according to 2 is on both sides of the hull 18 at the edge 10 an edge piece 16 attached by means of a non-positive connection. As can be seen from the figure, the edge piece 16 while the front side of the fuselage 18 attached. The attachment of the edge piece 16 can also be done via a non-positive or positive connection. The edge piece 16 forms the raised edge, which conforms to the shape of the rounded edges 12 the hollow roller 4 is adjusted. The edge piece 16 is made of a different material than the hull 18 of the inner body 6 educated. Since both sides of the trunk 18 two equal edge pieces 16 are arranged, is the inner body 6 characterized by a symmetrical structure, even if the edge pieces 16 and the hull 18 are formed of different materials.

Alternatively, it is also possible only in one of the border areas 10 an edge piece 16 provide, wherein in the opposite edge region of the fuselage 18 of the inner body 6 is formed profiled, such that the radius R _{I of} the inner body 6 towards the front side 14 rising steadily, leaving the shape of this edge area 10 of the inner body with the shape of the edge piece 16 is identical. So that the inner body 6 is equally hard in both edge areas, is the edge piece 16 in this case, in particular, of the same material as the hull 18 educated.

The embodiment of the rolling element 2 according to 3 differs from that according to the preceding figure only in that the edge piece 16 not on the front side of the fuselage 18 but around the perimeter of the hull 18 is arranged in the manner of a ring.

According to the embodiment 4 is a sealing element 20 provided, which in a recording 22 on the edge piece 16 is arranged. The recording 22 is formed in this case in the manner of a circumferential notch and the sealing element 20 is an O-ring that extends around the perimeter of the inner body 6 extends. The sealing element 22 touches the hollow roller 4 in the area of its rounded edge 12 , wherein the contact point between the sealing element 20 and the hollow roller 4 is at a radius R _K , which is smaller than the radius R _{I of} the inner body 6 , but is greater than the radius R _{D of} the through hole 8th ,

The edge pieces 16 according to 2 . 3 and 4 have a concave shape when seen from the outside, with the convex shape of the rounded edges 12 the hollow roller 4 corresponds. On the contrary, the edge profile has 16 in 5 a convex shape and immediately contacts the rounded edge 12 , The edge profile 16 is made of a material with suitable elasticity, such. B. made of hard rubber, designed so that its guiding function is supplemented in the axial direction by a sealing function.

2

rolling elements

4

hollow roller

6

inner body

8th

Through Hole

10

border area

12

rounded edge

14

front

15

cage pocket

16

margin copy

18

hull

20

poetry

22

admission

A

axis of rotation

K

contact point between sealing element and rounded edge

R _D

radius d. Through Hole

R _I

radius d. inner body

R _K

radius d. Contact point between seal and rounded edge

S

gap

Ax

axial game

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

• - US 3620585 [0004]
• - DE 102007062391 [0005]

Claims (13)

Rolling elements ( 2 ) for a rolling bearing, comprising a hollow roller ( 4 ) with one along an axis of rotation (A) of the hollow roller ( 4 ) extending through bore ( 8th ) and an inner body ( 6 ) with a cylindrical hull ( 18 ), which with a radial clearance fit coaxially in the through hole ( 8th ), characterized in that the hollow roller ( 4 ) and the inner body ( 6 ) are formed for a positive connection in the axial direction. Rolling elements ( 2 ) according to claim 1, characterized in that the edge regions ( 10 ) of the hollow roller ( 4 ) and / or the inner body 6 ) are designed to form the positive connection. Rolling elements ( 2 ) according to claim 2, characterized in that the radius (R _I ) of an end face ( 14 ) of the inner body ( 6 ) is greater than the radius (R _D ) of the through hole ( 8th ). Rolling elements ( 2 ) according to claim 3, characterized in that on the hull ( 18 ) at the edge ( 10 ) an edge piece ( 16 ) is arranged, through which the radius (R _I ) of the inner body ( 6 ) towards the front ( 14 ) increases. Rolling elements ( 2 ) according to one of claims 3 or 4, characterized in that the hull ( 18 ) at the edge ( 10 ) is profiled, so that the radius (R _I ) of the inner body ( 6 ) towards the front ( 14 ) increases. Rolling elements ( 2 ) according to one of the preceding claims, characterized in that the hollow roller ( 4 ) to the through hole ( 8th rounded edges ( 12 ) and the edge regions ( 10 ) of the inner body ( 6 ) are concave, wherein a radius of curvature of the concave edge regions ( 10 ) a rounding radius of the rounded edges ( 12 ) corresponds. Rolling elements ( 2 ) according to one of claims 1 to 5, characterized in that the hollow roller ( 4 ) to the through hole ( 8th rounded edges ( 12 ) and the edge regions ( 10 ) of the inner body ( 6 ) are convex and the rounded edges ( 12 ) of the hollow roller ( 4 ) to contact. Rolling elements ( 2 ) according to one of the preceding claims, characterized in that on the inner body ( 6 ) a recording ( 22 ) for a sealing element ( 20 ) is provided. Rolling elements ( 2 ) according to claim 8, characterized in that the contact point (K) between the sealing element ( 20 ) and the hollow roller ( 4 ) at the edge ( 10 ) lies. Rolling elements ( 2 ) according to one of claims 4 to 9, characterized in that the edge piece ( 16 ) annularly around the circumference of the trunk ( 18 ) is arranged. Rolling elements ( 2 ) according to one of claims 4 to 9, characterized in that the edge piece ( 16 ) on the front side of the fuselage ( 8th ) is arranged. Rolling elements ( 2 ) according to one of claims 4 to 11, characterized in that the edge piece ( 16 ) of a different material than the hull ( 18 ) is trained. Rolling bearing comprising a plurality of rolling elements with at least one rolling element ( 2 ) according to any one of the preceding claims.