GB1559567A

GB1559567A - Bearing

Info

Publication number: GB1559567A
Application number: GB11474/78A
Authority: GB
Original assignee: Caterpillar Tractor Co
Current assignee: Caterpillar Inc
Priority date: 1977-07-07
Filing date: 1978-03-22
Publication date: 1980-01-23
Also published as: CA1086363A; DE2829792A1; JPS5417448A; HK72783A; DE2829792C2

Description

(54) BEARING (71) We, CATTERPILLAR TRACTOR CO., a corporation organized and existing under the laws of the State of California, United States of America, of 100 N. E. Adams Street, Peoria, Illinois 61629, United States of America 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 :- Machine assemblies, such as an automotive crankshaft and journal bearing assembly for example, frequently incorporate thrust bearings for limiting axial motion. The thrust bearing is inserted in a cavity between the crankshaft, engine block and main journal bearing to limit motion along the axis-ouf rotation of the crankshaft. The thrust bearing has two faces winch bearing surface material on one surface only. The bearing is sometimes inadvertently inserted incorrectly with the bearing surface material towards the engine block surface which is stationary relative to the thrust bearing instead of the crankshaft thrust face or cheek which moves relative to the bearing. This damages the crankshaft and bearing.

It is desirable to have a bearing which has bearing surface material only on one surface, but which cannot be inserted incorrectly.

To this end, according to the present invention, an assembly comprises first and second relatively rotatable members, each of which has a radially extending and axially directe surface, surfaces being directe towards each other and de fining a cavity between them, the cavity having a portion of reduced crosssectional area, and a thrust bearing in the cavity, the bearing comprising a body having a periphery and a bearing surface, and a tab extending from the periphery adjacent the bearing surface, the tab being so dimensioned and arrange that it lies in the portion of the cavity of reduced cross-sectional area with the bearing surface directe towards one of the two axially facing surfaces and the tab preventing the bearing from being inserted into the cavity with the bearing surface towards the other of the two axially facing surfaces, and the tab also being spaced from the first and second members in the portion of the cavity of reduced cross-sectional area when the body of the bearing is in contact with the other of the two axially facing surfaces.

Three examples of thrust bearing assemblies in accordance with the invention incorporated in an automotive crankshaft assembly are illustrated in the accompanying drawings, in which :- Figure I is a side view of part of the crankshaft with the bearing assembly in section ; Figure 2 is an isometric view of one example of the thrust bearing ; Figure 3 is a cross-sectional view similar to part of Figure 1, but to a larger scale ; Figure 4 is a view similar to Figure 2, but of a second example of the bearing ; Figure 5 is a cross-section view similar to Figure 3 but of a second example ; and Figure 6 is a cross-sectional view similar to Figure 3 but of a third example.

Referring to Figure 1, a crankshaft 10, a main journal bearing 12 and part 14 of an engine block define between them a cavity 16. The block 14 has a protrusion 18 which extends toward a lobe 19 and cheek or thrust face 20 of the crankslaaft 10. The journal bearing 12 is held in the block 14 and preferably has its ends generally flush therewith (Figure 3). Alternatively an end portion 13 of the bearing 12 can extend to a location generally flush with the protrusion 18 (Figures 5, 6). The shape of the cavity 16 is influence by the relationship of the bearing 12, the crankshaft chebek 20 and the block 14.

Refcr, ing to Figures 2 and 3, a thrust bearing 21, preferably like a washer, is positioned in the cavity 16. The bearing 21 has a body portion 22, a bearing surface 24, inner and outer peripheries 26, 28 and at least one tab 30 adjacent the surface 24.

The tab 30 preferably extends outwardly from the outer periphery 28 in opposed relation to the inner periphery 26. The tab 30 is preferably of a smaller cross-sectional di- mension than the brody 22 of the bearing 21 and is shaped for insertion of the bearing 21 into the cavity 16 with the surface 24 oriente only toward the crankshaft cheek 20 defining the cavity 16. The tab 30 prevents insertion in any other manner by abbuting the protrusion 18 and preventing the body 22 of the bearing 21 from entering the cavity 16.

The tab 30 abuts the washer surface 24 which is preferably a bearing surface. The tab 30 and washer 21 are preferably constructed of steel and the surface 24 is pre ferahly bonded bearing material such as aluminium. The tab 30 is spaced a preselected distance from the engine block protrusion 18 when the washer body 22 and engine block 14 are in abutting contact.

The washer 21 has an arcuate configuration, preferably semi-circular, and has first and second end portions 32, 34 (FIG. 2, 4). The end portions 32, 34 are preferably tapered. The tab 30 is preferably spaced a preselected distance from the end portions 32, 34. The tab 30 can extend radially outward from the outer peripheral surface 28 or inwardly from-the interperipheral surface 26 from the first end portion 32 to the second end portion 34.

There can be more than one tab 30.

Referring to FIGS. 4-6, the tab 30 can extend inwardly from the inner periphery 26 in opposed relation to the outer periphery 28. The tab 30 can be tapered adjacent the surface 24 and the body 22 can be tapered adjacent the tab 30.

In operation, an assembler inserts the thrust bearing 21 into the cavity 16 with the surface 24 adjacent the crankshaft cheek 20.

If the assembler attempts to insert the thrust bearing 21 with the bearing surface 24 ad jacent the engine block 14, the tab 30 abots the engine block protrusion 18 or the journal bearing end portion 36 and prevents incorrect insertion.

Claims

WHAT WE CLAIM IS :- 1. An assembly comprising first and second relatively rotatable members, each of which has a radially extending and axially directe surface, the surfaces being directe towards each other and defining a cavity between them, the cavity having a portion of reduced cross-sectional area, and a thrust bearing in the cavity, the bearing comprising a body having a periphery and a bearing surface and a tab extending from the periphery adjacent the bearing surface, the tab being so dimensioned and arranbed trat it lies in the portion of the cavity of reduced cross-sectional area with the bearing surface directe towards one of the two axially facing surfaces and the tab preventing the bearing from being inserted into the cavity with the bearing surface towards the other of the two axially facing surfaces, and the tab also being spaced from the first and second members in the portion of the cavity of reduced cross sectional area when the body of the bearing is in contact with the other of the two axially facing surfaces.
2. An assembly according to Claim 1, in which the body of the bearing has inner and outer peripheries and said tab extends inwardly from said inner periphery in opposed relation to said outer periphery.
3. An assembly according to Claim 1 in which the body of the bearing has inner and outer peripheries and said tab extends outwardly from said outer periphery in opposed relation to said inner periphery.
4. An assembly according to any one of the preceding Claims, wherein said tab is tapered adjacent said bearing surface.
5. An assembly according to any one of the preceding Claims, in which the bearing is arcuately shaped and has first and second end portions.
6. An assembly according to Claim 5, wherein said tab is peripherally spaced a preselected distance from said end portions.
7. An assembly according to Claim 5 or Claim 6, wherein said end portions are taperez.
8. An assembly according to any one of the preceding claims, wherein said body is tapered adjacent said tab.
9. An assembly according to Claim 1, substantially as described with reference to Figures 1 to 3, of Figures 4 and 4, or Figure 6 of the accompanying drawings.
10. An automotive crankshaft assembly comprising a crankshaft having a cheek, a main journal bearing rotatably supporting the crankshaft and an engine block super porting the main journal bearing wherein the cheek forms the first relatively rotatable member of an assembly in accordance with any one of the preceding claims and a part of the engine block forms the second of the relatively rotatable members bearing surface of the thrust bearing being directe towards the cheek.
11. An automotive crankshaft assembly according to Claim 10, substantially as described with reference to Figures 1 to 3, or Figures 4 and 5, or Figures 6 of the accompanying drawings.