GB1563935A

GB1563935A - Cage

Info

Publication number: GB1563935A
Application number: GB54127/76A
Authority: GB
Original assignee: Ransome Hoffmann Pollard Ltd
Current assignee: Pilgrim House Group Ltd
Priority date: 1976-12-24
Filing date: 1976-12-24
Publication date: 1980-04-02

Description

(54) CAGE (71) We, RANSOME HOFFMANN POL LARD LIMITED, a British Company of New Street, Chelmsford, Essex, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method, by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a cage for locating the rollers in a roller bearing.

Such roller bearing cages are usually made of a metal such as brass or steel. Typically, such a cage is constituted by an annular end wall, from which axially extend a plurality of equispaced spacers, and a cap. The rollers are positioned between adjacent pairs of spacers and the cap is then rivetted to the free ends of the spacers to complete the cage. The spacers are so shaped that the cage locates the rollers and prevents them from falling out of the cage. The rollers are, of course, free to rotate about their own axes.

The main disadvantage of cages made in this way is that of cost. Thus, in order to carry out the rivetting process, holes must be drilled through the cap and into the spacers.

This necessitates holding the cap firmly on the spacers so that each pair of holes is accurately in register. This entails a fiddly, time-consuming operation which is expensive from the point of view of labour costs. Further difficulties arise because the hot-pressing step, which forms the rivet heads during the rivetting process, is also time-consuming.

Further expense is often entailed owing to the high breakage rate of the drill bits used.

One solution to these probelms, is to mould the cages of plastics material. Unfortunately, this is only economically viable where a very large number of cages are needed. Consequently, plastics moulded cages are not suitable for the entire range of sizes of roller hearings.

The present invention provides a cage for a roller bearing, the cage comprising a body portion and a cap, the body portion having an annular base and a plurality of equispaced roller-spacing arms extending axially from the base, and th cap being annular, wherein the free end portion of each arm is provided with a notch, the notches being positioned and sized to receive the cap.

Advantageously, the notches are formed in the radially outer surface of the. arms. The cap is arranged to be a fairly tight fit in the notches and can be inserted by being pushed over the free ends of the arms to snap into the notches, the arms each moving slightly inwardly to permit this. Once the cap is in the notches, the arms move resiliently back to the original positions to hold the cap firmly.

The cap may be in the form of a circlip; this facilitates the snapping of the cap into the notches because the circlip can be opened out slightly during this process, and thus per mits a tight friction fit between the cap and the notches to be achieved. Preferably, the free ends of the circlip are formed with complementary interlocking portions; these interlocking portions help to prevent the circlip from rotating when the bearing is in use.

Alternatively, rotation could be prevented by providing the free ends of the circlip with lugs which would locate between the rollerspacing arms.

Advantageously, however, the cap is continuous around its circumference, that is, the cap is a plain ring. In this case, it is preferable to hold the ring firmly in place by means of a circlip in notches in the roller-spacing arms.

Both cap and circlip may be located in the same series of notches, but preferably a further series of notches is provided for the circlip adjacent to the first series for the cap. Here, the ring cap is placed over the arms and pushed down until it snaps into its notches, the arms each moving slightly inwards to permit this. The circlip is then snapped into its notches, these notches being positioned closely adjacent to the first series of notches so that the circlip presses the ring in the direction of the base of the body portion. In order to increase the pressure of the circlip on the ring, each of the notches of the second series may be formed with a chamfer.

As compared with the provision of a circlip serving as the cap, the provision of a plain ring as the cap and a separate circlip to hold the ring tends to reduce the possibility of the cap being dislodged by the rollers in use of the bearing.

In either case, all the parts of the cage can be made of metal and as assembly of the cage is quick and easy, it will be apparent that the unit cost of such a cage will be considerably less than that of a comparable prior art rivetted cage.

Two forms of roller bearing cage constructed in accordance with the invention, will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of the first form of cage; Figure 2 is an axial section taken through one of the spacer arms of the cage of Figure 1; Figure 3 is a perspective view of the second form of cage; and Figure 4 is an axial-section taken through one of the spacer arms of the cage of Figure 3.

Referring to the drawings, Figure 1 shows a cage constituted by a main body portion I and a cap in the form of a circlip 2. The main body portion 1 is made of a metal such as brass or steel and comprises an annular base portion 3 and a plurality of equispaced spacer arms 4, the arms extending axially from the base. Adjacent to it's free end, each arm 4 is provided with a notch 5, the notches being situated on the radially outer surfaces of the arms and being sized and positioned to receive the circlip 2 in a tight friction fit. The circlip 2 is formed by cutting through an annular metallic ring (brass or steel). As can be seen from Figure 1 the cut, denoted by the reference numeral 6, is ofjagged or "jig-saw" shape so that, in use the free ends of the circlip interdigitate. This helps to stop the circlip 2 from rotating when the cage is in use.

In order to assemble the cage, the rollers (not shown) are positioned between adjacent pairs of arms 4. The circlip 2 is then forced over the free ends of the arms 4. During this forcing process, the arms 4 move slightly inwardly and the circlip 2 widens out slightly to permit the circlip to ride over the wider diameter of the ends of the arms. The circlip 2 is then pushed down until it snaps into the notches 5 where it is held as a tight friction fit.

Once the circlip 2 is in the notches 5, the arms 4 move back to their original positions and the circlip closes up once more.

Figures 3 and 4 show the second form of cage. Here, the cage is constituted by a main body portion 10, a cap 11 in the form of an annular ring, and a circlip 12 for holding the cap firmly in position. All three parts of the cage are made of a metal such as brass or steel. The body portion 10 comprises an annular base portion 13 and a plurality of equispaced spacer arms 14, the arms extending axially from the base portion. Adjacent to its free end, each arm 14 is provided with a pait of adjacent notches 15 and 16, the notches being situated on the radially outer surfaces of the arms. The notches 15 are shaped and positioned to support the ring 11 and the notches 16 are shaped and positioned to receive the circlip 12 in such a manner that it forces the ring firmly against the vertical side walls of the notches 15 (as seen in Figure 4).

In order to assemble the cage, the rollers (not shown) are positioned between adjacent pairs of arms 14. The ring 11 is then pushed over the free ends of the arms 14 and into the notches 15. The circlip 12 is then forced over the free ends of the arms 14 and snapped into the notches 16, the arms moving slightly inwardly and the circlip opening out slightly to permit this. When in position, the circlip 12 forces down hard on the ring 11 and prevents the ring from rotating when the cage is in use.

A number of modifications could be made to the cages described above. In particular, the wall of the notches 5 or 16 further from the base portion 3 could be tapered slightly.

This allows for manufacturing tolerances of the circlip notches 5 or 16, the circlips 2 or 12 themselves and, in the case of the embodiment of Figures 3 and 4, the thickness of the ring 11. This tapering also increases the sideways force, either of the circlip 2 against the side of the notch 5 nearest to the base portion or of the circlip 12 against the ring 11.

Thus, in the former case there is still less tendency for the circlip 2 to rotate when in use, and in the latter case there is similarly even less tendency for the ring 11 to rotate.

Further, the caps 2 or 11 could be formed with notches on the face nearest to the base portion to interlock with the arms 4 or 14 to prevent rotation.

An advantage of the construction of Figures 3 and 4 over that of Figures 1 and 2 is that, with the latter, there is a tendency for the circlip to be opened, and possibly, displaced from its notches by the action of a roller on the ends of the circlip, whereas, with the former, this tendency is greatly reduced since the rollers do not bear directly against the circlip.

WHAT WE CLAIM IS:- 1. A cage for a roller bearing, the cage comprising a body portion and a cap, the body portion having an annular base and a plurality of equispaced roller-spacing arms extending axially from the base, and the cap being annular, wherein the free end portion of each arm is provided with a notch, the notches being positioned and sized to receive the cap.

2. A cage as claimed in claim 1, in which the cap is in the form of circlip.

3. A cage as claimed in claim 2, wherein the free ends of the circlip are formed with complementary interlocking portions.

4. A cage as claimed in claim 2, wherein the free ends of the circlip are provided with

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. the ring tends to reduce the possibility of the cap being dislodged by the rollers in use of the bearing. In either case, all the parts of the cage can be made of metal and as assembly of the cage is quick and easy, it will be apparent that the unit cost of such a cage will be considerably less than that of a comparable prior art rivetted cage. Two forms of roller bearing cage constructed in accordance with the invention, will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of the first form of cage; Figure 2 is an axial section taken through one of the spacer arms of the cage of Figure 1; Figure 3 is a perspective view of the second form of cage; and Figure 4 is an axial-section taken through one of the spacer arms of the cage of Figure 3. Referring to the drawings, Figure 1 shows a cage constituted by a main body portion I and a cap in the form of a circlip 2. The main body portion 1 is made of a metal such as brass or steel and comprises an annular base portion 3 and a plurality of equispaced spacer arms 4, the arms extending axially from the base. Adjacent to it's free end, each arm 4 is provided with a notch 5, the notches being situated on the radially outer surfaces of the arms and being sized and positioned to receive the circlip 2 in a tight friction fit. The circlip 2 is formed by cutting through an annular metallic ring (brass or steel). As can be seen from Figure 1 the cut, denoted by the reference numeral 6, is ofjagged or "jig-saw" shape so that, in use the free ends of the circlip interdigitate. This helps to stop the circlip 2 from rotating when the cage is in use. In order to assemble the cage, the rollers (not shown) are positioned between adjacent pairs of arms 4. The circlip 2 is then forced over the free ends of the arms 4. During this forcing process, the arms 4 move slightly inwardly and the circlip 2 widens out slightly to permit the circlip to ride over the wider diameter of the ends of the arms. The circlip 2 is then pushed down until it snaps into the notches 5 where it is held as a tight friction fit. Once the circlip 2 is in the notches 5, the arms 4 move back to their original positions and the circlip closes up once more. Figures 3 and 4 show the second form of cage. Here, the cage is constituted by a main body portion 10, a cap 11 in the form of an annular ring, and a circlip 12 for holding the cap firmly in position. All three parts of the cage are made of a metal such as brass or steel. The body portion 10 comprises an annular base portion 13 and a plurality of equispaced spacer arms 14, the arms extending axially from the base portion. Adjacent to its free end, each arm 14 is provided with a pait of adjacent notches 15 and 16, the notches being situated on the radially outer surfaces of the arms. The notches 15 are shaped and positioned to support the ring 11 and the notches 16 are shaped and positioned to receive the circlip 12 in such a manner that it forces the ring firmly against the vertical side walls of the notches 15 (as seen in Figure 4). In order to assemble the cage, the rollers (not shown) are positioned between adjacent pairs of arms 14. The ring 11 is then pushed over the free ends of the arms 14 and into the notches 15. The circlip 12 is then forced over the free ends of the arms 14 and snapped into the notches 16, the arms moving slightly inwardly and the circlip opening out slightly to permit this. When in position, the circlip 12 forces down hard on the ring 11 and prevents the ring from rotating when the cage is in use. A number of modifications could be made to the cages described above. In particular, the wall of the notches 5 or 16 further from the base portion 3 could be tapered slightly. This allows for manufacturing tolerances of the circlip notches 5 or 16, the circlips 2 or 12 themselves and, in the case of the embodiment of Figures 3 and 4, the thickness of the ring 11. This tapering also increases the sideways force, either of the circlip 2 against the side of the notch 5 nearest to the base portion or of the circlip 12 against the ring 11. Thus, in the former case there is still less tendency for the circlip 2 to rotate when in use, and in the latter case there is similarly even less tendency for the ring 11 to rotate. Further, the caps 2 or 11 could be formed with notches on the face nearest to the base portion to interlock with the arms 4 or 14 to prevent rotation. An advantage of the construction of Figures 3 and 4 over that of Figures 1 and 2 is that, with the latter, there is a tendency for the circlip to be opened, and possibly, displaced from its notches by the action of a roller on the ends of the circlip, whereas, with the former, this tendency is greatly reduced since the rollers do not bear directly against the circlip. WHAT WE CLAIM IS:-

1. A cage for a roller bearing, the cage comprising a body portion and a cap, the body portion having an annular base and a plurality of equispaced roller-spacing arms extending axially from the base, and the cap being annular, wherein the free end portion of each arm is provided with a notch, the notches being positioned and sized to receive the cap.

2. A cage as claimed in claim 1, in which the cap is in the form of circlip.

lugs for engagement with the roller-spacing arms.

5. A cage as claimed in claim 1, wherein the cap is continuous around its circumference.

6. A cage as claimed in claim 5, wherein a circlip engaged in further notches in the rollerspacing arms is provided which bears against the cap to hold it in position.

7. A cage as claimed in claim 6, wherein the circlip engages a tapered wall of each further notch to urge the circlip against the cap.

8. A cage is claimed in any one of claims 1 to 7, wherein the notches are formed on the radially outer surfaces of the arms.

9. A cage for a roller bearing substantially as hereinbefore described with reference to Figure 1 or Figure 2 of the accompanying drawings.

10. A roller bearing incorporating a cage constructed in accordance with any of the preceding claims.