GB2260386A

GB2260386A - Preventing movement of an article along a shaft

Info

Publication number: GB2260386A
Application number: GB9214081A
Authority: GB
Inventors: Keith William Woodbridge; Daniel James Doncaster; Ronald Francis Hamblin
Original assignee: Svenska Kullagerfabriken AB
Current assignee: SKF AB
Priority date: 1988-12-05
Filing date: 1992-07-02
Publication date: 1993-04-14
Anticipated expiration: 2012-07-02
Also published as: GB9214081D0; GB2260386B

Abstract

For an assembly comprising a shaft (172) and an article (176) mounted on the shaft, a device (132) mounted on the shaft is provided which prevents movement of the article (176) along the shaft towards the device. The device (132) preferably comprises a ring and projections or "noses" (168) are provided, preferably as part of a cap (158), said projections etc. being produced separately from the device and the article. Alternatively the projections etc. may be pins (Figs 14 and 15) or may be formed on an annular member non-rotatably secured to the device, (Figs 16-18). <IMAGE>

Description

PREVENTING MOVEMENT OF AN ARTICLE ALONG A SHAFT This invention concerns an assembly comprising a shaft, an article which is mounted on the shaft and a device which is also mounted on the shaft and prevents movement of the article along the shaft in the direction from the article to the device, the device comprising an element extending at least part the way round the shaft and which, during assembly, can be moved along the shaft and then caused to adopt a position in which it lies in a first plane extending perpendicular to a second plane in which lies the longitudinal axis of the shaft, the first plane forming an angle with a third plane extending perpendicular to the longitudinal axis of the shaft which is no greater than tan~1 , where p is the coefficient of friction between the shaft and the element.

Such an assembly is the subject of GB-A-2169 376 and GB-A-2203 222. In these publications the device as illustrated comprises a ring having one or more projections or "noses" which contact the inner ring of a bearing (the article), the plane of the ring forming an angle no greater than tan'l p with a plane extending perpendicular to the axis of the shaft, p being the coefficient of friction between the ring and the shaft.

The device need not be a ring and could be horse-shoe shaped for example. For the sake of simplicity, in this specification a ring will be referred to but with the understanding that other shapes are to be included.

In most circumstances the assembly works very well and has merits of simplicity and ease of assembly.

The invention is characterised in that one or more members extend from the element to the article, the or each member having been produced separately from the element and article.

In an embodiment in which the element is a ring, fitting the ring to the shaft is accomplished by an axial force such as one or more blows at specified locations to lock it in place. This means that the ring has to be made of a sturdy material such as wrought steel. The production of integral projections or "noses" complicates the manufacture of the ring. By having separately produced members taking the place of the or each projection, the manufacture and production of the ring is simplified.

Preferably, the or each member is provided by an annular component interposed between the element and the article. Such a component can be relatively easily moulded from plastics or can be made from steel.

Preferably, the annular component and the element have cooperating formations which prevent rotation of one with respect to the other; which formations may be clips on the annular component engaging in recesses in the element.

The or each member may be a pin engaging in a bore in the element. The fit of the pin may be a clearance or interferance fit. With a clearance fit, the pin may be secured by an adhesive or by welding.

Preferably, the or each member is part of a cap which includes an annular portion which surrounds the element and a radially inwardly extending flange portion which is positioned between the element and the article.

Such a cap provides a measure of protection for the element from accidental knocks and blows which may otherwise dislodge the element.

Preferably a cover is provided which engages the annular portion of the cap and has a flange portion which extends radially inwardly, the element lying between the flange portions of the cap and cover.

Such a cover will assist in protecting the assembly from the environment, for example stones and grass wrap which are to be found in agricultural applications.

The flange portion of the cover may have a bore to allow the shaft to extend there through or may form a closed or blank end.

To withstand impacts that might dislodge the element or ring, the cap may be of plastics but is preferably of metal, but the cover may be of plastics.

Preferably, the element and the cap have co-operating formations which prevent rotations of one with respect to the other. This ensures that the element and the cap are correctly aligned in the assembly. When fitting the element or ring, the axial force or blow(s) applied are made at the correct specified location with respect to the projection(s) or nose(s) if the element and cap have only one relative position.

In one aspect of this feature, the cap has an "external" keyway and the element has an "internal" keyway.

Preferably, the cap has a sealing lip contacting the article, which lip may be inclined.

If, for example, the article is a rolling bearing, with the cap abutting the inner ring, the sealing lip contacts the outer ring, providing additional protection for the bearing from environmental contamination.

The cap with sealing lip is preferably an integral, moulded one-piece plastics component.

However, it may be a multi-part component, the parts being produced separately and which then may be secured together, and the parts may be of dissimilar materials, for example, metal and plastics.

In the accompanying drawings: Figure 1 is an end view of a sheet metal protective cap with integral noses; Figure 2 is a section on the cap of Figure 1 taken on II - II; Figure 3 is an end view of a moulded plastics protective cap with an integral nose; Figure 4 is a section on the cap of Figure 3 taken on IV - IV; Figure 5 is a side view of the cap of Figure 3; Figure 6 is an end view of a moulded plastics protective cap with an integral nose and a sealing lip; Figure 7 is a section on the cap of Figure 6 taken an VII - VII1 Figure 8 is an end view of a locking ring for use with the caps of Figures 1 to 7; Figure 9 is a section on the locking ring of Figure 8 taken on IX - IX;; Figure 10 is an end view of an assembly comprising a stepped shaft, a locking ring as shown in Figures 8 and 9, a protective cap as shown in Figures 6 and 7 and a ball bearing; Figure 11 is a section on the assembly of Figure 10 taken on XI - XIt Figure 12 is an end view of an assembly comprising a shaft, a locking ring as shown in Figures 8 and 9, a protective cap as shown in Figures 6 and 7 and a ball bearing, with the locking ring, cap and bearing located within the end cap of an idler conveyor roller; Figure 13 is a section on the mounting of Figure 12 taken on XIII - XIII; Figure 14 is an end view of a locking ring having two axially extending apertures; Figure 15 is a section on the ring of Figure 14 taken on XV - XV and showing a stepped pin for fitting in one of the apertures to provide a nose;; Figure 16 is an end view of a combination of a locking ring and an annular moulded platics component, which component provides two noses; Figure 17 is a side view of the combination of Figure 16; Figure 18 is a view of the combination of Figure 19 taken from the opposite end.

Figures 1 and 2 show one construction; Figures 3, 4 and 5 show a second construction and Figures 6 and 7 show a third construction of a cap suitable for use with the locking ring 132 shown in Figures 8 and 9. This locking ring 132 is a plain circular ring with no noses or projections. The ring has an axially extending slot or groove 134 in its radially outer circumferential surface forming an internal keyway and has inner curved bevelled edges 136.

Figures 1 and 2 show a cap 138 which is made of sheet metal with an annular outer portion 140 and a radially inwardly extending flange portion 142. The annular portion 140 has a projection 144 punched radially inwardly and forming an external keyway for interengagement with the slot 134 of the locking ring 132 (shown in broken line in Figure 2). The flange portion 142 has two projections 146 bent back inside from its radially inner periphery. These projections 146 take the place of the projections or noses 142 and 143 on the locking ring 140 of Figures 11 and 12 of GB-A-2,169,376 so simplifying the manufacture of the locking ring 132.

Figures 3 to 5 show a cap 148 moulded out of plastics. The cap 148 has an annular outer portion 150 and a radially inwardly extending flange portion 152. The annular portion 150 has a radially inwardly and longitudinally extending projection 154 on its inner surface forming an external keyway for interengagement with the slot 134 of the locking ring 132 (shown in broken line in Figure 4). The flange portion 152 has a thicker segment 156 forming a projection extending back inside the cap 148. This projection 156 takes the place of the projections or noses 142 and 143 on the locking ring 140 of Figures 11 and 12 of GB-A-2,169,376.

Figures 6 and 7 show a cap 158 which is a development of the cap 148 of Figures 3 to 5. The cap 158 is moulded from plastics and like the cap 148, comprises an annular outer portion 160, a flange portion 162, a projection 164 for interengagement with the slot 134 of the locking ring 132 (shown in broken line in Figure 7) and a projection 166. In addition the cap 158 has an annular projection 168 extending from the radially inner periphery of the flange portion 162 and an annular inclined sealing lip 170 extending from the radially outer periphery of the flange portion 162.

Although not shown, each of the caps 138, 148 and 158 may be used in combination with a plastics cover engaging the annular outer portion of the cap.

The cover has a flange portion which extends radially inwardly, with the locking ring lying between the flange portions of the cap and the cover. The flange portion of the cover has a bore through which a shaft extends or the flange portion forms a closed or blank end.

Figures 10 and 11 shown an assembly comprising a shaft 172 having a shoulder 174, a radial ball bearing 176 mounted on the smaller diameter portion of the shaft, the cap 158 of Figures 6 and 7 and the locking ring 132 of Figures 8 and 9. The bearing 176 is mounted with the inner ring butting up against the shoulder 174; the cap 158 is mounted with the projection 168 contacting the inner ring and the lip 170 contacting the outer ring; and the locking ring 132 is arranged inside the annular portion 160 and contacting the projection 166.

Figures 12 and 13 show one end of a conveyor roller mounted for rotation on a shaft 178 by means of a ball bearing 180. The roller has an end cap 182 which provides a seating bore 184 for the bearing 180 and leads to a radially inwardly extending flange 186. Between the flange 186 and the bearing 180 there is arranged a seal plate 188. The bearing 180 is prevented from moving axially in the outboard direction by means of a combination of the cap 158 of Figures 6 and 7 and the locking ring 132 of Figures 8 and 9. The projection 168 of the cap 158 abuts the inner ring of the bearing 180 and the lip 170 is in sealing contact with the outer ring of the bearing.

Figures 14 and 15 show a locking ring 190, which is a plain circular ring with bevelled edges in its bore. The ring 190 has two bores 192 and two stepped pins 194 (only one of which is shown) are formed separately from the ring for fitting in the bores.

The pins 194 may be of plastics or metal, maybe a loose or tight fit in the bores 192 and may be secured by gluing or welding or left loose. With the pins 194 in place, the ring 190 has the required projections or noses for preventing movement of an article on a shaft.

Figures 16, 17 and 18 show a locking ring 196 in combination with a separately formed annular plastics component 198. The plastics component 198 provides two projections or noses 200. The locking ring 196 has two recesses 202 in its outer periphery, and the annular component 198 has two L-shaped elastically bendable arms 204 which engage in the recesses 202 and hold the component to the ring and prevent their relative rotation.

Claims

1. An assembly comprising a shaft, an article mounted on the shaft and a device which is also mounted on the shaft and prevents movement of the article along the shaft in the direction from the article to the device, the device comprising an element extending at least part the way round the shaft and which, during assembly, can be moved along the shaft and then caused to adopt a position in which lies in a first plane extending perpendicular to a second plane in which lies the longitudinal axis of the shaft, the first plane forming an angle with a third plane extending perpendicular to the longitudinal axis of the shaft which is no greater than tan'l p, where A is the coefficient of friction between the shaft and the element, characterised in that one or more members extend from the element to the article, the or each member having been produced separately from the element and article.

2. An assembly as claimed in claim 1, wherein the or each member is provided by an annular component interposed between the element and the article.

3. An assembly as claimed in claim 2, wherein the element and the annular component have co-operating formations which prevent rotation of one with respect to the other.

4. An assembly as claimed in claim 1, wherein the or each member is a pin engaging in a bore in the element.

5. An assembly as claimed in claim 1,2,3 or 4, wherein the or each member is part of a cap which includes an annular portion which surrounds the element and a radially inwardly extending flange portion which is positioned between the element and the article.

6. An assembly as claimed in claim 5, wherein a cover is provided which engages the annular portion of the cap and has a flange portion which extends radially inwardly, the element lying between the flange portions of the cap and cover.

7. An assembly as claimed in claim 6, wherein the cover has a bore through which the shaft extends.

8. An assembly as claimed in claim 5, 6 or 7, wherein the element and the cap have co-operating formations which prevent rotation of one with respect to the other.

9. An assembly as claimed in any one of claims 5 to 8, wherein the cap has a sealing lip contacting the article.

10. An assembly comprising a shaft, an article mounted on the shaft and a device which is also mounted on the shaft and prevents movement of the article along the shaft in the direction from the article to the device substantially as herein described with reference to and as shown in the accompanying drawings.