Bearings – Rotary bearing – Antifriction bearing
Reissue Patent
2001-03-15
2003-03-04
Hannon, Thomas R. (Department: 3682)
Bearings
Rotary bearing
Antifriction bearing
C384S579000
Reissue Patent
active
RE038015
ABSTRACT:
This application claims the benefit of Japanese Patent Application No. 9-287627, and a Japanese Application (No. not yet assigned, attorney's docket No. 98NSP057) filed Sep. 10, 1998 which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a roller bearing with a cage on which a large load or an impact load is to be imposed, and more specifically, to a technology to facilitate the assembly or to enhance the durability thereof.
2. Related Background Art
A roller bearing with a cage is frequently used for supporting a gear shaft, a spindle, rollers, etc., since in a reduction apparatus for a rolling mill, a pinion stand, a crusher, or the like, a large load or an impact load is caused to act on each of the constituent parts and, moreover, the apparatus itself vibrates severely. With such roller bearing with a cage, rollers are supported by a pin-type cage or a stud-type cage so that a friction or damage of rollers and the main body of the case caused by the mutual contact is not brought about, and the rollers can be securely retained.
A roller bearing with a pin-type cage is a bearing for retaining rollers by means of a pin-type cage which comprises a plurality of pins and a pair of annular side plates for supporting the rollers to be rotatable. Such roller bearing is described in Japanese Utility Model Publication No. 49-37730, et al., and a structure in which such pin-type cage is applied to a conical roller bearing is shown in
FIGS. 10 and 11
.
In a pin-type cage
13
of a bearing
1
shown in
FIG. 10
, pins
11
and an annular side plate
17
are connected with each other by use of parallel screws, while the pins
11
and an annular side plate
15
are connected with each other by means of welding. More specifically, parallel screw portions
71
are formed at the fore ends of the pins
11
, and after these parallel screw portions
71
are inserted into through holes
73
which are formed on the annular side plate
17
, nuts
75
are screwed onto the parallel screw portions
71
, whereby the pins
11
and the annular side plate
17
are connected with each other. On the other hand, flange portions
77
are formed at the hind ends of the pins
11
. After these flange portions
77
are fitted in recesses
79
formed on the outer side surface of the annular side plate
15
, a weld is carried out to connect the pins
11
with the annular side plate
15
. It should be noted that when the pin-type cage
13
is to be assembled, the pins
11
and the annular side plate
17
are connected with each other after the pins
11
are inserted through rollers
7
.
Also, in a pin-type cage
13
of a bearing
1
shown in
FIG. 11
, a pin
11
and an annular side plate
15
are connected with each other by means of welding. On the other hand, the pin
11
and an annular side plate
17
are connected with each other by means of a cone screw. More specifically, a cone screw portion
81
is formed at the fore end of the pin
11
, and this cone screw portion
81
is screwed into a cone screw hole
83
which is formed on the annular side plate
17
, whereby the pin
11
and the annular side plate
17
are connected with each other.
On the other hand, a roller bearing with a stud-type cage is a bearing for retaining rollers by means of a cage which comprises a plurality of stud pins and stay-type pins and a pair of annular side plates. This roller bearing is described in U.S. Pat. No. 4099803, et al., and a structure in which such stud-type cage is applied to a cylindrical roller bearing is shown in FIG.
12
.
In a stud-type cage of a bearing
1
shown in
FIG. 12
, a stay
55
and two annular side plates
15
and
17
are connected with each other by press fitting or welding, meanwhile cylindrical rollers
7
are retained to be rotatable by stud pins
85
which are press fitted in the inner surface sides of the both annular side plates
15
and
17
.
There exist various demands for the above-mentioned roller bearing with a cage, in order to enhance the assembling performance or improve the strength of the bearing, or the like.
For example, in the pin-type cage shown in
FIG. 10
, which uses the parallel screws for connecting the pins
11
and the annular side plate
17
, a jig is required for adjusting a space between the both annular side plates
15
and
17
, and moreover, close attention much to be paid when each nut
75
is fastened, which results in a very poor assembling performance. On the other hand, with respect to the pin-type cage shown in
FIG. 11
which uses the cone screws, if a manufacturing error of a referential diameter of the cone screw is great, the axial position of the pin
11
with respect to the annular side plate
17
becomes hardly constant, so that the cone screw portion
81
may extrude inside the annular side plate
17
, as shown in FIG.
13
. In this case, a stress is concentrated on a trough of the cone screw portion
81
so that the strength of the pin
11
is decreased and the pin
11
may be broken or damaged due to its long use under severe use conditions. In addition, also in the roller bearing with the stud-type cage shown in
FIG. 12
in which a pin-type stay
55
is press fitted into the two annular side plates
15
and
17
and welded together, a jig is required for adjusting a space between the both annular side plates
15
and
17
. Moreover, if a space between the both annular side plates
15
and
17
is too narrow, the adjustment thereof is difficult, which results in a problem of a very poor production yield.
The pin
11
(or the stay-type pin
55
) and the annular side plate
17
(or the annular side plates
15
and
17
) are connected together by means of welding, as shown in
FIG. 14
(showing the essential part of the roller bearing with the pin-type cage of FIG.
11
). However, it is difficult to evaluate the quality of the welding part itself at a low cost, and there is another problem that some limitation may be placed on the hardening treatment or the like of the pin
11
. That is, though it is desirable that the pin
11
and the stay-type pin
55
be subjected to carburization or quenching treatment to enhance the hardness thereof, it is difficult to conduct such treatment on the entire body of the pin
11
or the stay-type pin
55
in order to prevent cracks in welding. As a result, it is difficult to reduce a frictional abrasion caused by the contact with a roller
13
or enhance the strength of the pin
11
or the stay-type pin
55
itself in a part in which a range for conducting the hardening treatment is restricted so that a desired hardness can not be obtained.
On the other hand, about a half of a load which is applied onto the pin
11
from the roller
13
is caused to act on a contact portion with the annular side plate
15
. However, in the above-mentioned conventional roller bearing, the flange portion
77
is positioned outside of the annular side plate
15
so that the length of action becomes large. As a result, a stress generated in the welding portion becomes great, which is disadvantageous for the purpose of enhancing this strength of the portion.
SUMMARY OF THE INVENTION
The present invention was conceived taking the above circumstances into consideration and an object of the invention is to provide a roller bearing with a cage which can facilitate the assembly or enhancing the durability of the bearing.
In order to achieve the above object, according to the present invention, there is provided a roller bearing with a cage comprising:
an inner race and an outer race concentric with each other;
a plurality of rollers interposed between the inner race and the outer race; and
a cage for retaining these rollers,
characterized in that:
the cage comprises a pair of annular side plates disposed at the both ends of the rollers for supporting the rollers to be rotatable, and a plurality of pins each having its both ends respectively connected to connection portions of the pair of annular side plates;
parallel screw portions are respectively formed at the b
Fujii Osamu
Mori Michitsugu
Murai Takashi
Hannon Thomas R.
Miles & Stockbridge P.C.
NSK Ltd.
LandOfFree
Roller bearing with a cage does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Roller bearing with a cage, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Roller bearing with a cage will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3030582