GB2102531A

GB2102531A - A combination of a support body and an annular pulley body

Info

Publication number: GB2102531A
Application number: GB08219979A
Authority: GB
Inventors: Roland Haas; Manfred Brandenstein; Rudiger Hans
Original assignee: SKF Kugellagerfabriken GmbH
Current assignee: SKF GmbH
Priority date: 1981-07-09
Filing date: 1982-07-09
Publication date: 1983-02-02
Also published as: IT8222305V0; IT8222188A0; GB2102531B; FR2509407B1; FR2509407A1; IT1190901B

Abstract

A pulley body (11) is mounted for rotation on a support body (10) by a rolling bearing (12). The support body (10) comprises two sleeves (16, 17) each having an open end and means (20, 24) defining an aperture (21, 25). The two apertures (21, 25) are arranged on an axis eccentric to the sleeves (16, 17) and are adapted to receive a bolt (26) for securing the support body (10) to a structure (27). One aperture (21) is positioned at one end of the support body (10) where the head of the bolt (26) will be. To stiffen the sleeve (17) providing the aperture (21) so that thinner walled and thus lighter sleeves can be used, the sleeve at that end having the aperture (21) has a radially outwardly extending annular flange (19) in the form of an annular head. The flange (29) also provides a larger contact area for the head of the bolt thus reducing the pressure on that end of the sleeve when the bolt is tightened. <IMAGE>

Description

SPECIFICATION A combination of a support body and an annular pulley body This invention is concerned with a combination of a support body and an annular pulley body.

U.K. Patent Application No. 8114672 (Serial No.

2076108) discloses an annular pulley body mounted on and for rotation relative to a support body by a rolling bearing having an inner race ring. The support body comprises two substantially identical sleeves, each having one end open and the other end closed. Aligned apertures, one in each closed end, form an eccentric bore in the support body for reception of an element, such as a bolt, for securing the support body to a structure. The sleeves extend one from each end of the inner race ring into the bore of the inner race ring. Each sleeve has a shoulder on its outer circumferential surface limiting how far the sleeve extends into the bore of the inner race ring and so axially locating the bearing in relation to the support body.This known combination of support body and annular pulley body has the advantage that, because the two sleeves are substantially identical, the manufacturing expense and the stock keeping of the parts during manufacture are kept low and relatively simple.

In order to reduce the weight of the combination the walls of the sleeves are made thinner. This, however, has meant that the sleeves can no longer withstand the compressive load of the bolt when tightened without deforming. Also the shoulders on the sleeves can quite easily be shorn off or damaged under these high loads. Further this design cannot be easily adapted so that the distance of the pulley body from the structure can be altered.

The subject of this invention is a combination of a support body and an annular pulley body in which the support body even when made from thin walled material is sufficiently rigid to withstand the com pressive load produced when tightening the bolt to secure the support body to a structure, in which that compressive load is transmitted through the various parts without any part being broken or damaged and in which the possible applications in which the combination can be used is increased without great additional expense.

The invention provides, in combination, a support body and an annular pulley body mounted on and for rotation relative to the support body by a rolling bearing having an inner race ring mounted on the support body, the support body comprising first and second sleeves each having one end open and means defining an aperture, the two apertures being arraged on a common axis parallel to but spaced from the axis of rotation of the pulley body, the two apertures being adapted to receive an element for securing the support body to a structure, and one aperture being positioned at one end of the support body, wherein the support body has at that one end a radially outwardly extending annular flange.

The aperture and annularflange at that one end are at the end where, when the support body is secured to a structure by a bolt, the head of the bolt is. The annular flange stiffens that sleeve providing the annular flange and thus allows that sleeve to be made from a relatively thin walled material so allowing the weight to be kept low. The annular flange also enlarges the abutment surface for the head of the bolt so reducing the pressure on that sleeve.

The first sleeve of the support body may provide the annular flange, which flange may abut one end of the inner race ring, and the first sleeve may extend axially from the said one end of the inner race ring through the bore and protrude beyond the other end of the inner race ring.

With such a construction the compressive load due to tightening of the bolt is transmitted between the bolt head and the structure through the inner race ring. Also that portion of the first sleeve extending axially through the bore of the inner race ring can support and centre the second sleeve.

The second sleeve of the support body may be mounted on the protruding portion of the first sleeve and abuts the said other end of the inner race ring.

A relatively large area of contact between one end of the second sleeve and the said other end of the inner race ring reduces the pressure of the compressive load produced when the bolt is tightened.

The other end of the second sleeve will abut the structure, when the support body is secured to the structure by a boit, and so fixes the distance of the pulley body from the structure. The second sleeve can be easily altered or changed so that the distance of the pulley body from the structure can be altered.

A stock of second sleeves can be kept, all having a maximum length. To shorten the distance of the pulley body from the structure, a second sleeve is simply cut to the desired shorter length.

For each sleeve the means defining the aperture may comprise a radially inwardly extending integral projection at one end of the sleeve, and the support body may have an aperture at each end. Alternatively, a wall may be fixed to the sleeve and define the aperture.

Preferably the annular flange of the support body is an annular bead provided by a fold in the material of the first sleeve.

With the features of the annular flange abutting one end of the inner race ring and the second sleeve abutting the other end of the inner race ring and the structure, the compressive load when the bolt is tightened is transmitted between the bolt head, the annular flange, the inner race ring and the second sleeve. The portion of the first sleeve extending through the bore of the inner race ring is thus subject to only light loads.

Am embodiment of the invention will now be described by way of example, reference being made to the accompanying drawings, of which: Figure 1 is a longitudinal section and Figure 2 is an end view of a combination of a support body and an annular pulley body.

The combination shown in the drawings comprises a support body 10 and an annular pulley body 11 mounted on and for rotation relative to the support body by a rolling bearing 12.

The rolling bearing 12 is a single row deep groove ball bearing comprising an inner race ring 13, an outer race ring 14 and a row of balls 15.

The support body 10 comprises two sleeves 16 and 17 each with a co-axial bore, the two bores lying on a common axis. First sleeve 17 has a cylindrical portion 18 with one end open and at the other end a radially outwardly extending annular flange 19 in the form of an annular bead comprising a fold in the wall of the sleeve. An integral projection 20 extends radially inwardly from the flange 19 and defines, at one end of the sleeve 17, an aperture 21. The integral projection 20 also defines a further aperture 22 which is hexagonal in shape and is intended to be engaged by a tool such as a key, for turning the support body 20. The annular flange 19 abuts one axial end of the inner race ring 13 and the cylindrical portion 18 extends axially from that end through and protrudes from the other end of the inner race ring.

The second sleeve 16 is mounted on the protruding portion of the sleeve 17 and comprises a cylindrical section 23 having an open end into which the sleeve 17 extends. The open end of the sleeve 16 abuts the other end of the inner race ring 13 so that the inner race ring is caught between the open end of sleeve 16 and the flange 19. At the other end of the cylindrical section 23 of the sleeve 16 an integral projection 24 extends radially inwardly and defines an aperture 25.

Aperture 21 at one end of the support body 10 and aperture 25 at the other end are arranged on a common axis which is parallel to but spaced from the axis of rotation of the pulley body 11. The two apertures 21 and 25 define an eccentric bore in the support body 10 adapted to receive an element, such as a bolt 26 (shown in broken line), which secures the support body to a structure 27 such as part of a machine, the head of the bolt abutting the integral projection 20 of the sleeve 17.

The annular pulley body 11 comprises two sheet metal annular parts 28 and 29 which are pushed onto the outer race ring 14 and secured together by staking - sections 30 of one part being deformed to extend axially into the other part. The parts 28 and 29 may instead be secured together by welding or glueing. A pulley belt (not shown) will run on the circumferential surface of the pulley body 11. By engaging a tool in the aperture 22 at one end of the sleeve 17 and turning the support body 10 about the axis of the aligned apertures 21 and 25, the tension of the pulley belt is adjusted.

The distance A from the centre of the annular pulley body 11 to the side face of the structure 27 can be altered by replacing the sleeve 16 having the length B with a sleeve having a different length.

When the bolt 26 is tightened to secure the support body 10 to the structure 27, the compressive load between the head of the bolt and the structure is transmitted through the annular flange 19, the inner race ring 13 and the sleeve 16. The annular flange 19 stiffens the sleeve 17 and provides a larger contact area for the head of the bolt 26 so reducing the pressure.

Claims

1. A combination of a support body and an annular pulley body mounted on and for rotation relative to the support body by a rolling bearing having an inner race ring mounted on the support body, the,support body comprising first and second sleeves each having one end open and means defining an aperture, the two apertures being arranged on a common axis parallel to but spaced from the axis of rotation of the pulley body, the two apertures being adapted to receive an element for securing the support body to a structure, and one aperture being positioned at one end of the support body, wherein the support body has at that one end a radially outwardly extending annular flange.

2. A combination as claimed in claim 1, wherein the first sleeve of the support body provides the annular flange, which flange abuts one end of the inner race ring, and the first sleeve extends axially from the said one end of the inner race ring through the bore and protrudes beyond the other end of the inner race ring.

3. A combination as claimed in claim 2, wherein the second sleeve of the support body is mounted on the protruding portion of the first sleeve and abuts the said other end of the inner race ring.

4. A combination as claimed in claim 1,2 or 3, wherein for each sleeve the means defining the aperture comprises a radially inwardly extending integral projection at one end of the sleeve, the support body having an aperture at each end.

5. A combination of a support body and an annular pulley body substantially as herein described with reference to and as shown in the accompanying drawings.