Seal device for rolling bearing

Details Seal device for rolling bearing Seal device for rolling bearing

1998-03-12

2001-03-27

Knight, Anthony (Department: 3626)

Seal for a joint or juncture

Seal between relatively movable parts

Circumferential contact seal for other than piston

C277S560000, C277S562000, C277S571000

Reexamination Certificate

active

06206380

ABSTRACT:

TECHNICAL FIELD OF THE INVENTION
The present invention is related to a seal device for a rolling bearing, for an example, to be installed in any of a support apparatus for automobile vehicle or a rotational support portion in various industrial machines and apparatus.
BACKGROUND OF THE INVENTION
Various machines and apparatus have rotational support portions in which rolling bearings such as ball bearings, roller bearings or tapered roller bearings are installed. Such rolling bearings have seal devices installed therein, so that grease filled in the interior of the rolling bearings is prevented from leaking out or various kinds of foreign matter such as rain water or dust on the outside are kept from entering the interior of the rolling bearings.
FIGS. 1
to
3
show three examples of conventional seal devices installed in the opening portion at one end of a rolling bearing for the purposes mentioned above.
FIG. 1
shows a first example of the conventional seal device structures as disclosed in Japanese Patent Publication Tokuko Hei2-52140, which comprises a radially outer seal ring
3
and a radially inner seal ring
4
in combination. This seal device is mounted between an outer ring
8
and an inner ring
11
, portions of which are illustrated in FIG.
1
. The rotational center of the outer and inner rings
8
,
11
is located on the lower side of the inner ring
11
in FIG.
1
. The radially outer seal ring
3
comprises a reinforcing metal member
1
a
and a seal member
2
a,
and the radially inner seal ring
4
comprises a reinforcing metal member
1
b
and a seal member
2
b,
In this structure, the seal member
2
a
of the seal ring
4
is formed with one or two seal lips having a tip end edge placed in sliding contact with a surface portion of the reinforcing metal member
1
a
of the mating seal ring
3
, while the seal member
2
b
of the seal ring
3
is formed with one or two seal lips having a tip end edge placed in sliding contact with a surface portion of the reinforcing metal
1
b
of the mating seal ring
4
.
FIG. 2
shows a second example of the conventional seal device structures as disclosed in Japanese Utility Model Publication JitsuKaiHei 2-146221, which comprises a reinforcing metal member
5
, a slinger
6
and seal member
7
. This seal device is mounted between an outer ring
8
and an inner ring
11
, portions of which are illustrated in FIG.
2
. The rotational center of the outer and inner rings
8
,
11
is located on the lower side of the inner ring
11
in FIG.
2
.
The seal member
5
is formed in an annular shape with a L shaped cross section, and comprises a radially outer cylindrical portion
9
and a radially inner ring portion
10
. The radially outer cylindrical portion
9
is adapted to be fitted into and fixed to the inner peripheral portion at one end of the outer ring
8
, and the radially inner ring portion
10
extends radially inwards from the axially inner end edge of the cylindrical portion
9
. The term “axially inner end edge” is used to mean the end edge closer to the axially central portion of the rolling bearing (the left end edge in FIG.
2
).
The slinger
6
is formed in an annular shape with an L shaped cross section, and comprises a radially inner cylindrical portion
12
and a radially outer ring portion
13
. The radially inner cylindrical portion
12
is adapted to be fitted onto and fixed to the outer peripheral portion at one end of the inner ring
11
, and the radially outer.,, ring portion
13
extends radially outwards from the anally outer end edge of the cylindrical portion
12
. The term “axially outer end edge” is used to mean the end edge closer to the axial opening portion of the rolling bearing (the right end edge in FIG.
2
).
The seal member
7
is made of an elastic material such as rubber or elastomer and has a base portion
7
a
and three seal lips, i.e. outer seal lip
14
, intermediate seal lip
15
and inner seal lip
16
. The base portion
7
a
is securely connected to the reinforcing metal
5
.
The outermost seal lip
14
has a tip end edge placed in sliding contact with an axially inner surface portion of the ring portion
13
of the slinger
6
and the remaining seal lips, i.e intermediate seal lip
15
and inner seal lip
16
, have tip end edges placed in sliding contact with the outer peripheral surface portion of the cylindrical portion
12
of the slinger
6
.
FIG. 3
shows a third example of the conventional seal device structures as disclosed in Japanese Utility Model Publication JitsuKaiHei 3-121224, which is formed in a structure similar to that of the second example in
FIG. 2
, except that the innermost seal lip
16
of the three seal lips of the seal member
7
is tilted in a direction opposite to that of the second example, with its tip end edge closer to the axial central portion of the rolling bearing.
The three examples mentioned above are still required to be improved in some points as follows;
In the example of
FIG. 1
, the radially outer and inner seal rings
3
,
4
comprising the reinforcing metal members
1
a,
1
b
and the seal members
2
a,
2
b,
are troublesome in manufacturing so as to increase the cost of the whole seal device.
In the example of
FIG. 2
, the tip end edge of the inner seal lip
16
is inclined to be separated from the outer peripheral surface of the cylindrical portion
12
of the slinger
6
before installing the seal device to the open end portion of the rolling bearing or before installing the rolling bearing with the seal device to a rotational support portion.
Once the tip end edge of the seal lip
16
is separated from the outer peripheral surface of the cylindrical portion
12
of the slinger
6
, the inner seal lip
16
often turns over when the tip end edge of the seal lip
16
is fitted onto the outer peripheral surface of the cylindrical portion
12
of the slinger
6
by relatively axially moving the reinforcing metal member
5
and slinger
6
closer to each other. In the turned-over state, the contact pressure between the tip end edge of the seal lip
16
aid the outer peripheral surface of the cylindrical portion
12
of the slinger
6
is excessively large, so that the rotational torque, that is rotational resistance in the rolling bearing with the seal device installed therein, becomes large and the seal performance becomes instable.
In order to avoid such problems, the axial length of the cylindrical portion
12
may be enlarged, or the tip end edge of the inner seal lip
16
can be made closer to the ring portion
13
of the slinger
6
to increase the axial length between the tip end edge of the inner seal lip
16
and the axially inner end edge of the cylindrical portion
12
of the slinger
6
. However, if the axial length of the cylindrical portion
12
is enlarged, the installation space of the seal device will sometimes become intolerably large. And, if the tip end edge of the inner seal lip
16
is made closer to the ring portion
13
of the slinger
6
, the distance between the tip end edge of the seal lip
16
and the tip end edge of the intermediate seal lip
15
is too short to cause interference therebetween so as to worsen the seal performance.
In the example of
FIG. 3
, even if the tip end edge of the seal lip
16
is separated from the outer peripheral surface of the cylindrical portion,
12
of the slinger
6
, the inner seal lip
16
never turns over when the tip end edge of the seal lip
16
is fitted onto the outer peripheral surface of the cylindrical portion
12
of the slinger
6
. However, when the performance of the inner seal lip
16
for preventing grease leakage is too perfect, grease hardly reaches the sliding contact portions between the intermediate and outer seal lips
15
,
16
and the slinger
6
. Accordingly, the wear at the sliding contact portions can become large and the seal performance can be worsened at the sliding contact portions.
In addition, when the root portion
16
a
of the inner seal lip
16
and the root portion
15
a
of the intermediate seal lip
15
, connected to the base port

Affiliated with

Also associated with

Rating

Seal device for rolling 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 Seal device for rolling bearing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Seal device for rolling bearing will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2544078