Bearings – Rotary bearing – Antifriction bearing
Reexamination Certificate
2002-09-26
2003-12-30
Hannon, Thomas R. (Department: 3682)
Bearings
Rotary bearing
Antifriction bearing
C277S351000, C277S353000
Reexamination Certificate
active
06669373
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to a sealing device disposed between inner and outer races rotatable relative to each other such as, for example, between inner and outer races of a rolling bearing assembly or between inner and outer races that forms respectively a part of a rotary shaft and a part of a housing, for sealing an inner space between the outer and inner races from an external environment and, more particularly, to the sealing device for a bearing that utilizes a combination of a sealing plate such as a slinger and a sealing lip.
2. Description of the Prior Art
Hitherto, such a sealing device for an axle bearing as shown in
FIG. 7
has been utilized. The sealing device
10
shown in
FIG. 7
is used to seal an inner annular space between a fixed inner race and a rotatable outer race and includes an inner peripheral sealing plate
51
of a generally L-sectioned configuration and an outer peripheral sealing strip
52
of a generally L-sectioned configuration. The inner and outer peripheral sealing plates
51
and
52
are so arranged and so positioned relative to each other as to define a generally rectangular sectioned annular space therebetween. The illustrated sealing device
10
also includes an elastic strip
53
made of, for example, rubber and integrated together with the outer peripheral sealing plate
52
. This elastic strip
53
has sealing lips such as a side seal lip
53
a
and radial seal lips
53
b
and
53
c
, all formed integrally therewith. These side seal lip
53
a
and the radial seal lips
53
b
and
53
c
are held in contact with a radial upright wall
51
a
and a cylindrical wall
51
b,
respectively, both forming respective parts of the inner peripheral sealing plate
51
. The radial upright wall
51
a
of the inner peripheral sealing plate
51
extends radially outwardly from the cylindrical wall
51
b
so as to terminate spaced a slight distance inwardly from a cylindrical wall
52
b
of the outer peripheral sealing plate
52
to define a labyrinth seal
54
between the radial upright wall
51
a
and the cylindrical wall
52
b.
An outer annular surface C of the radial upright wall
51
a
of the inner peripheral sealing plate
51
is held in flush with an annular end face A of the elastic strip
53
on the cylindrical wall
52
b
of the outer peripheral sealing plate
52
. It is, however, to be noted that the annular end face A is in practice represented by an annular outer end face of a portion of the elastic strip
53
that is turned around a corresponding end of the cylindrical wall
52
b
of the outer peripheral sealing plate
52
.
On the other hand, as shown in
FIG. 8
, the conventional axle bearing
200
including a rotatable inner race structure and a fixed outer race structure has been known, which includes an outer race
34
having an outer peripheral surface formed integrally with a radial flange through which the axle bearing
200
is fitted to an automobile body structure, and also having an inner peripheral surface formed with dual raceways
33
and
33
; an inner race assembly including inboard and outboard inner races
36
and
36
having respective raceways
35
and
35
defined therein in face-to-face relation with the dual raceways
33
and
33
in the outer race
34
; respective rows of rolling elements
37
and
37
rollingly accommodated between the raceways
33
and
33
in the outer race
34
and the raceways
35
and
35
in the inboard and outboard inner races
36
and
36
; and inboard and outboard sealing devices
30
B and
30
C for sealing an annular space delimited between the outer race
34
and the inboard and outboard inner races
36
and
36
.
The rolling elements
37
are retained by a retainer
39
with a predetermined circumferential space between the neighboring rolling elements
37
.
To reduce the weight of the axle bearing
200
, the width of the outer race
34
as measured in a direction axially of the axle bearing
200
is chosen to be smaller than the width of the inner race assembly, that is, the total width of the paired inner races
36
and
36
also as measured in a direction axially of the axle bearing
200
. The outer race
34
and the inner race assembly are so positioned relative to each other that an annular end face of the outer race
34
on an outboard side is held in flush with an annular end face of the outboard inner race
36
, but the opposite annular end face of the outer race
34
on an inboard side is set back axially inwardly from an annular end face of the inboard inner race
36
.
The inboard sealing device
30
B includes a sealing plate
63
A, which serves as a core, and a seal lip member
38
formed integrally therewith. The sealing plate
63
A is mounted on a shoulder at an inner end of the outer race
34
. The seal lip member
38
has an inner peripheral edge formed with bifurcated radial lips
38
b
and
38
c
that are slidingly engaged with an outer peripheral surface of an inboard end of the inboard inner race
36
. The outboard sealing device
30
c
includes a sealing plate
63
B, which serves as a core, and a seal lip member
38
formed integrally therewith. The sealing plate
63
B is mounted to an inner periphery of the outer race
34
. The seal lip member
38
of the outboard sealing device
30
c
has an inner peripheral edge formed with bifurcated radial lips
38
b
and
38
c
that are slidingly engaged with an outer peripheral surface of an outboard end of the outboard inner race
36
. The radial flange
32
integral with the outer race
34
is formed with a bolt hole
44
defined therein for passage therethrough of a corresponding bolt used to secure the axle bearing
200
to a knuckle carried by the automobile body.
To further reduce the weight of the axle bearing
200
, as shown in
FIG. 9
, in a manner similar to the opposite annular end face of the outer race
34
on an inboard side, the outboard annular end face of the outer race
34
can be set back axially inwardly from the outboard annular end face of the outboard inner race
36
. In such case, the inboard and outboard sealing devices
30
B and
30
C may have a structure identical with each other.
In the prior art sealing device
10
shown in
FIG. 7
, the annular end face A of the cylindrical wall
52
b
of the outer peripheral sealing plate
52
and the outer annular surface C of the radial upright wall
51
a
of the inner peripheral sealing plate
51
are held in flush with each other in respect of the datum, that is, as a theoretically accurate geometric reference. Considering a step occurring in an actual produce between the annular end face A and the outer annular surface C, and also considering a design tolerance and a possible variation which would occur during assembly in view of the plate thickness of each of the sealing plates
51
and
52
, the worst case it may occur would be that the outer annular end face C will protrude a distance outwardly, i.e., rightwards as viewed in
FIG. 7
, from the plane of the annular end face A.
The prior art sealing device
10
makes use of a labyrinth seal
54
as a means for avoiding ingress of muddy water in cooperation with the three seal lips
53
a,
53
b
and
53
c.
This labyrinth seal
54
is formed between a free end face a of the radial upright wall
51
a
of the inner peripheral sealing plate
51
and an inner peripheral face b of the cylindrical wall
52
b
of the outer peripheral sealing plate
52
.
However, if the outer annular end face C protrudes outwardly from the annular end face A as discussed hereinabove, the width of the labyrinth seal
54
as measured in a direction axially of the sealing device will decrease, accompanied by reduction in the capability of the labyrinth seal
54
to avoid the ingress of muddy water.
In the prior axle bearing
200
of the structure shown in
FIG. 8
or
FIG. 9
, the outer peripheral surface of the inboard end of the inboard inner race
36
, with which the bifurcated radial lips
38
b
and
38
c
of the seal lip member
38
are slidingly engaged, are e
Ohtsuki Hisashi
Suzuki Shougo
Tajima Eiji
Hannon Thomas R.
NTN Corporation
LandOfFree
Sealing device for a bearing does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sealing device for a bearing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sealing device for a bearing will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3179485