GB2126669A

GB2126669A - Flanged plain bearing and method of making the same

Info

Publication number: GB2126669A
Application number: GB08323608A
Authority: GB
Inventors: Eric Winston Dickson; Nigel Henry New
Original assignee: AE PLC
Current assignee: AE PLC
Priority date: 1982-09-03
Filing date: 1983-09-02
Publication date: 1984-03-28
Also published as: GB8323608D0

Abstract

A method of manufacturing a flanged plain bearing from a bearing blank 21 having a bearing backing and a bearing lining of a bearing material. A series of slits 23 are formed in a first region 22 of the blank which is to become a flanged portion 12. The first region is folded to a position in which it is perpendicular to the remainder of the blank and the blank is bent into a semi-cylindrical shape. The first region can be folded prior to the bending or the blank may be bent prior to the folding but in either case, the slits must be formed prior to one of these operations. The resulting bearing comprises a journal portion and a flange portion providing a thrust surface, the flange portion being integral with the journal portion and being made up of a series of discrete tabs 13. <IMAGE>

Description

SPECIFICATION Flanged plain bearing and method of making the same The present invention relates to plain bearings having thrust surfaces in the form of flanges, and to methods of their manufacture.

In known flanged plain bearings with flanges which are continuous, it is sometimes difficult to lubricate effectively the entire thrust surface with fresh lubricant.

It is an object of the invention to provide a flanged plain bearing having a thrust surface with improved lubrication characteristics.

Known methods for producing flanged plain bearings suffer the disadvantage that the radial extent of the flange may be severely limited as a result of the "stretching" of the material required to form the flange. A related problem is the difficulty in obtaining a shape which is even, without buckling and which is truly partcylindrical, again due to the stretching of the flange.

It is therefore a further object of the invention to provide a method of producing a flanged plain bearing which does not suffer from these disadvantages.

According to one aspect of the present invention, a method of manufacturing a flanged plain bearing from a bearing blank having a metal backing and a bearing lining of a bearing material, comprises forming a series of slits in a first region of the blank which is to become a flange portion, folding the first region to a position in which the first region is substantially perpendicular to the remainder of the blank and bending the blank into a cylindrical or part-cylindrical shape, the slits being formed prior to at least one of the folding and bending operations.

Thus, the first region may be folded prior to the bending of the blank or alternatively the blank may be bent prior to the first region being folded.

The slits may be formed prior to both these operations but must be formed prior to one of the operations.

Preferably, the base of each slit is rounded.

This may help to reduce the risk of tearing at the base of the slit.

Preferably, the fold between the journal portion and the flange portion is spaced from the bases of the slits. This may help to avoid bend lines and flattening in the journal portion extending from the slits, particulariy when the first region is folded prior to the bending operation.

According to another aspect of the invention, a flanged plain bearing comprising a journal portion and a flange portion providing a thrust surface, each portion having a metal backing and a bearing lining of a bearing material, the flange portion being integral with the journal portion and being discontinuous.

The discontinuous nature of the flange means that lubricant can be supplied to and removed from the thrust surface at intervals along its extent, thus improving the lubrication characteristics.

Preferably the flange portion comprises a series of discrete tabs which may be located at regular intervals about the journal portion. There may be a flange portion at each end of the journal portion. The journal portion may be completely cylindrical or part-cylindrical.

The backing may be of any suitable material such as steel or aluminium or aluminium alloy. The lining may be of a soft metal bearing alloy or may be a plastics bearing material or a plastics alloy.

This invention may be carried into practice in various ways and some embodiments will now be described by way of example with reference to the accompanying dawings in which: Figure 1 is an isometric sketch of a cylindrical bearing with a discontinuous flange; Figures 2 and 5 show the main stages in one method of manufacturing a semi-cylindrical bearing with a discontinuous flange; Figures 6 to 9 show the main stages in another method of manufacturing a cylindrical bearing with a discontinuous flange; Figure 10 is a detail to a larger scale of a portion of Figure 4 showing a modification thereof; and Figure 11 is a view similar to Figure 5, showing a modification thereof.

Figure 1 shows a plain bearing comprising a journal portion 11 and a discontinuous flange portion 12 at one end. The flange portion 1 2 comprises a number (in this case 8) of tabs 13 which extend radially outwardly perpendicular to the journal portion 11 to define a thrust surface 14. The bearing is made from a blank comprising a metal (e.g. steel) backing and a lining of bearing material. In the finished bearing shown in Figure 1, the lining is located at the inner surface 1 5 of the journal portion and at the thrust surface 1 4.

Naturally, the number of tabs 13 can be varied, and a second flange portion could be formed at the other end of the journal portion 11.

Figures 2 and 5 show the main stages in the manufacture of a semi-cylindrical bearing with a discontinuous flange portion at each end. Firstly (Figure 2), a blank 21 having a metal (e.g. steel) backing and a lining of bearing material is cut to size. Secondly (Figure 3), two opposite side portions 22 are folded to a position perpendicular to the remainder of the blank 21 , with the bearing lining at the outside surfaces of the side portions 22. Thirdly (Figure 4), a series of slits 23 are formed in the upstanding side portions 22. Finally (Figure 5), the blank 21 is bent into a semi cylindrical shape to define a journal portion 24 and two flange portions 25 with the bearing lining at the inner journal surface and the outer flange surfaces. The result of this bending operation is that the slits 23 open out into a V-shape to leave tabs 26 defining the flange portions.

It will be appreciated that the presence of the slits 23 allows the blank 21 to be bent without fear of the disadvantages associated with "stretching" of the flange portion. Furthermore, the flange portion 25 formed is discontinuous resulting in improved lubrication of the flange portion 25 in the final bearing.

Figures 6 to 9 show the main stages in the manufacture of a cylindrical bearing with a discontinuous flange portion at one end. Firstly (Figure 6), a blank 31, having a metal (e.g. steel) backing and a lining of bearing material is cut to size. Secondly (Figure 7), a series of slits 32 are formed in the blank 31 along one side portion 33.

Thirdly (Figure 8), the blank 31 is bent into a cylindrical shape with the bearing lining at the inside surface and the slits 32 at one end. Finally (Figure 9), the side portion 33 including the slits 32 is folded outwardly to form a flange portion 35 which is perpendicular to the remainder of the blank 31. The remainder of the blank 31 constitutes a journal portion 34. the result of the folding operation is that the slits 32 open out into a V-shape to leave tabs 36 defining the flange portion 35. Again, the flange "stretching" problems are avoided and the desired configuration achieved.

If wished, the ends of the blank may be joined at the join line 37, e.g. by welding, preferably laser beam welding.

A semi-cylindrical bearing with a discontinuous flange at each end (as shown in figure 5) can also be manufactured by a variation of the method of figures 6 to 9. In this case the steps of figures 6 and 7 are combined so that a single blanking operation produces a rectangular blank of the required dimensions with slits along opposite edges. This is then bent to a semi-cylindrical shape and the tabs folded to define the flange portions in a manner similar to that shown in Figures 8 and 9.

In a modified method of manufacture as shown in Figure 10, the slits 23 are formed with a curved base 27. This helps to ensure that when the blank 21 is finally bent into its cylindrical or semicylindrical shape, the risk of tearing at the base of the slit is minimised.

When the slits 23 extend all the way to the fold line, it is sometimes difficult to avoid kinks extending from the slits 23 across the journal portion 24 with corresponding relatively flat section between the kinks. Therefore, in this modified method, the slits 23 stop short of the fold line of the flange portion 25. This helps to ensure a truly cylindrical or part-cylindrical final shape in the final journal portion 25.

Figure 11 shows a finished semi-cylindrical double-flanged bearing made with slits 23 as described with reference to Figure 1 0.

The modifications of Figures 10 and 11 are also applicable to the method described with reference to Figures 6 to 9.

Claims

1. A method of manufacturing a flanged plain bearing from a bearing blank having a metal backing and a bearing lining of a bearing material, comprising forming a series of slits in a first region of the blank which is to become a flanged portion, folding the first region to a position in which the first region is substantially perpendicular to the remainder of the blank and bending the blank into a cylindrical or part-cylindrical shape, the slits being formed prior to at least one of the folding and bending operations.

2. A method as claimed in Claim 1 in which the first region is folded prior to the bending of the blank.

3. A method as claimed in Claim 1 in which the blank is bent prior to the first region being folded.

4. A method as claimed in any preceding claim in which the slits are formed prior to both the folding and bending operations.

5. A method as claimed in any preceding claim in which the base of each slit is rounded.

6. A method as claimed in any preceding claim in which the fold between the journal portion and the flange portion is spaced from the bases of the slits.

7. A method of manufacturing a flanged plain bearing from a bearing blank having a metal backing and a bearing lining of a bearing material substantially as herein specifically described with reference to and as shown in Figures 2 to 5 or Figures 6 to 9 of the accompanying drawings, or Figures 2 to 5 or Figures 6 to 9 when modified in accordance with Figure 10.

8. A flanged plain bearing comprising a journal portion and a flange portion providing a thrust surface, each portion having a metal backing and a bearing lining or a bearing material, the flange portion being integral with the journal portion and being discontinuous.

9. A bearing as claimed in Claim 8 in which the flange portion comprises a series of discreet tabs located at regular intervals about the journal portion.

10. A flanged plain bearing constructed and arranged substantially as herein specifically described with reference to Figure 1, Figure 5, Figure 9, or Figure 11 of the accompanying drawings.