192 clutches and power-stop control – Clutches – Automatic
Reexamination Certificate
2003-08-21
2004-11-09
Rodriguez, Saúl J. (Department: 3681)
192 clutches and power-stop control
Clutches
Automatic
C192S113320
Reexamination Certificate
active
06814199
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a one-way clutch for use in a transmission of an automobile.
As a one-way clutch for use in a transmission of an automobile or the like, one is conventionally known such as in Japanese Examined Utility Model Publication No. Hei. 7-55391.
FIG. 8
shows a related one-way clutch and it includes an outer race
50
, an inner race
51
, a plurality of engaging members (sprags)
52
disposed between the inner and outer races, an inner retainer
53
, an outer retainer
54
, springs
55
, a pair of end bearings
56
, and the like.
The aforementioned sprags
52
are retained by the inner retainer
53
, and the outer retainer
54
in a space formed by the end bearings
56
fitted to opposite sides between the inner race
51
and the outer race
50
, and are disposed in such a manner as to be urged in one direction by the springs
55
disposed between the inner and outer retainers
53
and
54
. Each end bearing
56
is formed into a U-shaped cross section and is constituted by a first hollow cylindrical portion
57
fitted to an outer peripheral surface
51
a
of the inner race
51
, a second hollow cylindrical portion
58
fitted to an inner peripheral surface
50
a
of the outer race
50
, and an annular portion
59
which radially connects the first hollow cylindrical portion
57
to the second hollow cylindrical portion
58
. The annular portion
59
of each end bearing
56
having the U-shaped cross section is located on each outer side of the one-way clutch. Each annular portion
59
has substantially the same thickness from its inner periphery to its outer periphery and is formed in such a manner as to extend radially so as to be substantially perpendicular to the axis of the inner race
51
. In each of the end bearings
56
, an inner peripheral surface
57
a
of the first hollow cylindrical portion
57
opposing the outer peripheral surface
51
a
of the inner race
51
, as well as an outer peripheral surface
58
a
of the second hollow cylindrical portion
58
opposing the inner peripheral surface
50
a
of the outer race
50
, are formed as smooth surfaces.
In the above-described conventional one-way clutch, the end bearings
56
are disposed between the inner and outer races
51
and
50
and have a function as slide bearings. Namely, the inner peripheral surface
57
a
of the first hollow cylindrical portion
57
slides on the outer peripheral surface
51
a
of the inner race
51
, and the outer peripheral surface
58
a
of the second hollow cylindrical portion
58
slides on the inner peripheral surface
50
a
of the outer race
50
. The clearance between the inner race
51
and the first hollow cylindrical portion
57
of the end bearing
56
and the clearance between the outer race
50
and the second hollow cylindrical portion
58
of the end bearing
56
are made extremely small in view of securing the space for the sprags
52
of the one-way clutch. For this reason, there have been problems in that the friction, i.e., the drag torque, between the inner race
51
and the first hollow cylindrical portion
57
of the end bearing
56
and between the outer race
50
and the second hollow cylindrical portion
58
of the end bearing
56
cannot be made small, and that seizure is likely to occur. This friction constitutes a problem particularly between the inner race
51
and the first hollow cylindrical portion
57
. The reason is that consideration is generally given to eliminate as much as possible the clearance between the outer race
50
and the second hollow cylindrical portion
58
, which is located on the side where the peripheral speed is large, so as to prevent the occurrence of sliding between the two members
50
and
58
, whereas a clearance is provided between the inner race
51
and the first hollow cylindrical portion
57
, where the peripheral speed is small, so as to positively allow sliding to occur between the two members
51
and
57
.
In addition, to overcome the above-described problems, an arrangement has been proposed in which, as shown in
FIG. 9
, axial grooves
60
are formed at a plurality of circumferential positions in the inner peripheral surface
57
a
of the first hollow cylindrical portion
57
of the end bearing
56
by lathe turning machining, so as to lower the contact area. However, since the processing of the axial grooves
60
is effected by machining, there are problems in that the cost becomes high, and that mass productivity is poor.
SUMMARY OF THE INVENTION
In view of the above-described problems, the object of the invention is to provide a one-way clutch which excels in mass productivity and in which friction is small.
The object of the invention is to provide a one-way clutch in which an axial groove for enlarging the amount of lubricating oil retained and enhancing the reduction of friction between the first hollow cylindrical portion and the inner race is formed in the inner peripheral surface of the first hollow cylindrical portion of the end bearing.
In order to solve the aforesaid object, the invention is characterized by having the following arrangement.
(1) A one-way clutch comprising:
an inner race;
an outer race;
a plurality of engaging members disposed between the inner and outer races;
retainers for retaining the engaging members;
springs for urging the engaging members in one direction; and
a pair of end bearings which are respectively disposed on opposite sides between the inner race and the outer race, each of the end bearings having a U-shaped cross section and including,
a first hollow cylindrical portion fitted to an outer peripheral surface of the inner race,
a second hollow cylindrical portion fitted to an inner peripheral surface of said outer race,
an annular portion connecting the first hollow cylindrical portion to second hollow cylindrical portion, and
a plurality of recessed portions formed at least in the inner peripheral surface of the first hollow cylindrical portion of each of the end bearings.
(2) The one-way clutch according to (1), wherein the recessed portions are a plurality of dimple-like dents.
(3) The one-way clutch according to (1), wherein the recessed portions are axial grooves formed by press forming.
(4) The one-way clutch according to (1), wherein the recessed portions are axial grooves formed by press forming and a circumferential groove formed by press forming so as to intersect the axial grooves.
(5) A one-way clutch comprising:
an inner race;
an outer race;
a plurality of engaging members disposed between the inner and outer races;
retainers for retaining the engaging members;
springs for urging the engaging members in one direction; and
a pair of end bearings which are respectively disposed on opposite sides between the inner race and the outer race, each of the end bearings having a U-shaped cross section and including,
a first hollow cylindrical portion fitted to an outer peripheral surface of the inner race,
a second hollow cylindrical portion fitted to an inner peripheral surface of said outer race,
an annular portion connecting the first hollow cylindrical portion to second hollow cylindrical portion, and
a plurality of projections formed at least on the inner peripheral surface of the first hollow cylindrical portion of each of said end bearings.
(6) A one-way clutch including:
an inner race;
an outer race;
a plurality of engaging members disposed between the inner and outer races;
retainers for retaining the engaging members;
springs for urging the engaging members in one direction; and
a pair of end bearings which are respectively disposed on opposite sides between the inner race and the outer race, each of the end bearings having a U-shaped cross section and including,
a first hollow cylindrical portion fitted to an outer peripheral surface of the inner race,
a second hollow cylindrical portion fitted to an inner peripheral surface of said outer race,
an annular portion connecting the first hollow cylindrical portion to second hollow cylindrical portion, and
axial grooves which extend through to opposite ends of
Koyo Seiko Co. Ltd.
McGinn & Gibb PLLC
Rodriguez Saúl J.
LandOfFree
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