GB1589322A

GB1589322A - Bearings

Info

Publication number: GB1589322A
Application number: GB3076/77A
Authority: GB
Original assignee: Glacier Metal Co Ltd
Current assignee: Federal Mogul Engineering Ltd
Priority date: 1978-04-18
Filing date: 1978-04-18
Publication date: 1981-05-13

Description

(54) BEARINGS (71) We, ThE GLACIER METAL COMPANY LIMITED, a Company registered under the Laws of England, of 368, Ealing Road., Alperton, Wembley, Middlesex, do hereby declare this 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 plain journal bearing having a thrust flange at one or each axial end, and is related to the inventions the subject of British Patent Specifications No.l 16 8914 and 1512782 which were respectively for an electron beam method and a laser beam method of welding an end flange to a partcylindrical plain journal bearing shell.

According to the present invention a bearing comprises a part-cylindrical plain journal bearing shell, having a thrust flange welded to one or each axial end, by a continuous weld extending for substantially less than the complete circumferential length of the shell.

It has previously been thought necessary to weld the shell to the flange substantially all along the circumfential length of the end of the shell, but the high temperatures of laser beam or other welding, tends to induce stresses in the bearing after cooling, which may deform the shell, and may indeed impair its load bearing properties. It has been found that welding along a part only of the circumfential length does effectively unite the bearing components while allowing them some freedom of relative movement to alleviate those stresses, so that after welding a finished bearing is obtained without the necessity for further machining.

It will be appreciated that with the socalled thin walled bearings, which have to be able to deform a little to conform with the shape of the bearing housing, precise dimensions of the bearing make the bearing much easier to fit and use.

Usually thin walled bearings have a diameter a little greater than that of the corresponding recess in the bearing housing, and they are deformed and sprung into position. The difference between the diameters of the back of the journal shell, and the recess in the housing, is known as the "freespread" and a precise amount of freespread is most desirable. Also it is desirable that the flanges remain accurately perpendicular to the axis of the journal after welding has been completed.

The method according to the present invention enables these objects to be achieved to a large extent with shell and flange components which are simply pressed out of continous flat strip lined bearing material, the pressing in the case of the journal including the formation into a semi-cylindrical shell.

The continuous weld, preferably extends to either side of the centre of the bearing, but not as far as the circumferential ends, but in an alternative construction there are two portions of continuous welding, one at each circumferential end and no welding at the centre. In the latter case the thrust flange can be in two separated parts to assist in alleviating the stresses.

In a preferred form of the invention, the flange is radially narrower at the circumferential ends that at the central part to economise in the amount of strip material that is scrapped during pressing out the flanges.

Preferably, the flange and shell each have a backing and a lining of material having a lower melting point.

The invention may be carried into practice in various ways, and one embodiment will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a journal and thrust bearing shell; Figure 2 is an exploded view of the components of the bearing shell of Figure 1 before assembly; and Figure 3 is a sketch showing how the end flanges can be pressed out from continuous strip bearing material; The thin walled bearing shell comprises a semi-cylindrical journal shell 4, and a pair of end flanges 1 and 2, and each component consists of a strong backing, for example of steel or aluminium, with a softer bearing lining defining the rubbing surface. The semi < :ylin- drical shell 4 has a lubricant inlet hole 7 leading to a circumferential oil groove 5, and each end flange 1 or 2 has a pair of oil distribution grooves 6. Alocating notch is shown at 8.

The components are assembled by an electron beam or laser beam welding process, as described in British Patent Specification No.

1168914, or 1512782, but in order to reduce the stresses in the material arising as a consequence of the welding operation and in order to give the bearing reasonable ability to flex to be sprung into its bearing housing, welding is not along a complete semi-circular path, where the flange is in contact with the axial edge of the shell 4, and instead the welding in one embodiment is only along the central part of the semi-circular arc, as indicated by the line 'A' in Figure 2. That might be about a third of the length of the arc, and at the outer ends of the arc indicated at 'B', there is no union between the shell 4 and the flanges 1 and 2.

In an alternative embodiment, there is welding along the outer arcs 'B', but no union between the components along the central arc 'A' The actual method of welding can be as described in British Patent Specification No.

1168914, or 1512782, or 1536780.

The effect will be that the area intensely heated during the weld will be smaller than if the weld was along the whole semi-circular arc, and there will be less distortion set up as the material cools again. Thus the shape of the assembled bearing, shown in Figure 1, will be substantially as if the components in Figure 2 were assembled together without distortion, and in that way the components formed by simple pressing and bending operations can be made into a finished bearing without further machining after the welding operation, and can be acurately shaped so that the predetermined amount of freespread is available.

In the embodiment in which the welding is along the arc 'B' and not along the arc 'A', it would be possible to cut the flange 1 along the line 10 after welding to release any stresses that have been established in that part of the flange.

As an alternative it would be possible to form the flange 1 into separate portions each tending a right angle at the centre of the bearing, and welding them separately to the shell 4, each along one arc 'B'.

That method has the additional advantage that the flanges 1 and 2 can be pressed out from continuous sheet material with less wastage, and indeed that can be achieved even if they are pressed out as complete semi-circular flanges provided the shape is an indicated in dashed lines in Figures 1 and 2, in which at the circumferential ends of the bearing the greater diameter portions of the flanges are omitted.

Figure 3 shows at the left-hand end that with complete uniform radial thickness flanges, there is almost as much material scrapped from a continuous strip, as shown by the cross-hatched portion, as there is material used for the flanges. At the right-hand end of Figure 3, it can be seen how by removing the portions 9, it is possible to have a narrower strip and a much closer positioning of the flanges in the strip, so that there is less scrap material. The radial width of the flanges could be increased a little to give the same thrust area while still having a considerable saving in material scrapped.

WHAT WE CLAIM IS:- 1. A bearing comprising a part-cylindrical plain journal bearing shell having a thrust flange welded to one or each axial end by a continuous weld extending for substantially less than the complete circumferential length of the shell.

2. A bearing as claimed in Claim 1 in which the continuous weld extends to either side of the centre of the flange, but not as far as the circumferential ends.

3. A bearing as claimed in Claim 1 in which the continuous weld is at each circumferential end of the flange, but not at the centre.

4. A bearing as claimed in Claim 3 in which the thrust flange is in two separated parts.

5. A bearing as claimed in any of the preceeding claims in which the flange is radially narrower at the circumferential ends than at the central part.

6. A bearing as claimed in any of the preceding claims in which the shell and flange have each a backing, and a lining of a material having a lower melting point.

7. A bearing as claimed in any of the preceding claims in which the continuous weld is a laser beam weld, 8. A bearing comprising a part-cylindrical plain journal bearing shell having a thrust flange welded to one or each axial end substantially as herein specifically described with reference to the accompanying drawings.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. consequence of the welding operation and in order to give the bearing reasonable ability to flex to be sprung into its bearing housing, welding is not along a complete semi-circular path, where the flange is in contact with the axial edge of the shell 4, and instead the welding in one embodiment is only along the central part of the semi-circular arc, as indicated by the line 'A' in Figure 2. That might be about a third of the length of the arc, and at the outer ends of the arc indicated at 'B', there is no union between the shell 4 and the flanges 1 and 2. In an alternative embodiment, there is welding along the outer arcs 'B', but no union between the components along the central arc 'A' The actual method of welding can be as described in British Patent Specification No. 1168914, or 1512782, or 1536780. The effect will be that the area intensely heated during the weld will be smaller than if the weld was along the whole semi-circular arc, and there will be less distortion set up as the material cools again. Thus the shape of the assembled bearing, shown in Figure 1, will be substantially as if the components in Figure 2 were assembled together without distortion, and in that way the components formed by simple pressing and bending operations can be made into a finished bearing without further machining after the welding operation, and can be acurately shaped so that the predetermined amount of freespread is available. In the embodiment in which the welding is along the arc 'B' and not along the arc 'A', it would be possible to cut the flange 1 along the line 10 after welding to release any stresses that have been established in that part of the flange. As an alternative it would be possible to form the flange 1 into separate portions each tending a right angle at the centre of the bearing, and welding them separately to the shell 4, each along one arc 'B'. That method has the additional advantage that the flanges 1 and 2 can be pressed out from continuous sheet material with less wastage, and indeed that can be achieved even if they are pressed out as complete semi-circular flanges provided the shape is an indicated in dashed lines in Figures 1 and 2, in which at the circumferential ends of the bearing the greater diameter portions of the flanges are omitted. Figure 3 shows at the left-hand end that with complete uniform radial thickness flanges, there is almost as much material scrapped from a continuous strip, as shown by the cross-hatched portion, as there is material used for the flanges. At the right-hand end of Figure 3, it can be seen how by removing the portions 9, it is possible to have a narrower strip and a much closer positioning of the flanges in the strip, so that there is less scrap material. The radial width of the flanges could be increased a little to give the same thrust area while still having a considerable saving in material scrapped. WHAT WE CLAIM IS:-

1. A bearing comprising a part-cylindrical plain journal bearing shell having a thrust flange welded to one or each axial end by a continuous weld extending for substantially less than the complete circumferential length of the shell.

7. A bearing as claimed in any of the preceding claims in which the continuous weld is a laser beam weld,

8. A bearing comprising a part-cylindrical plain journal bearing shell having a thrust flange welded to one or each axial end substantially as herein specifically described with reference to the accompanying drawings.