Note: Descriptions are shown in the official language in which they were submitted.
1~86363
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 of rotation
of the crankshaft. The thrust bearing has two faces with bearing
surface material on one surface only. The bearing is sometimes
inadvertently inserted incorrectly with the bearing surface
material to~ards 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 hhich has a radially extending and axially directed sur-
face, the surfaces being directed towards each other and defin-
ing 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, thetabbeing so dimensioned and arranged that it
lies in the portion of the cavity of reduced cross-sectional
area with the bearing surface directed towards one of the two axially
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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 1 is a side view of part of the crankshaftwith 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
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and cheek or thrust face 20 of the crankshaft 10.
The journal bearing 12 is held in the block 14 and
preferably has its ends generally flush therewith
(Figure 3). ~lternatively an end portion 13 of the
5. bearing 12 can extend to a location generally flush
with the protrusion 18 (Figures 5, 6). The shape of
the cavity 16 is influenced by the relationship of
the bearing 12, the crankshaft cheek 20 and the block
14.
10. Referring to Figures 2 and 3, a bearing 21,
preferably a thrust bearing 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.
15. The tab 30 preferably extends outwardly from the outer
periphery 28 in opposed relation to the inner periphery
26. m e tab 30 is preferably of a smaller cross-sectional
dimension than the body 22 of the bearing 21 and is shaped
for insertion of the bearing 21 into the cavity 16 with
20. the surface 24 oriented only toward the crankshaft cheek
20 defining the cavity 16. The tab 30 prevents insertion
in any other manner by abutting the protrusion 18 and
. preventing the body 22 of the bearing 21 from entering
the cavity 16.
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1C~86363
The tab 30 abuts the washer surface 24 which is pre-
ferably a bearing surface. The tab 30 and washer 21 are
preferably constructed of steel and the surface 24 is preferably
bonded bearing material such as aluminum. The tab 30 is spaced
a preselected distance from the engine block protrusion 18 when
the ~asher body 22 and engine block 14 are in abutting contact.
The ~asher 21 has an arcuate configuration, preferably
semi-circular, and has first and second end portions 32, 34
~Figure 2, 4). The end portions 32, 34 are preferably tapered.
The tab 30 is preferabl~ 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 inner
peripheral surface 26, spaced from the first end portion 32 and
the second end portion 34. There can be more than one tab 30.
~eferring to Figures 4 - 6, the tab 30 can extend
in~ardly from the inner peripher~ 26 in opposed relation to
the outer peripher~ 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 adjacent the engine block
14, the tab 30 abuts the engine block protrusion 18 or the
journal bearing end portion 13 and prevents incorrect insertion.
Other aspects, objects and advantages will become
apparent from a study of the specification, drawings and appended
claims.
