U.S. patent application number 10/303460 was filed with the patent office on 2003-04-24 for axial force controlling method and bearing apparatus.
This patent application is currently assigned to Koyo Seiko Co., Ltd.. Invention is credited to Ishii, Tomohiro, Mitarai, Tadashi, Toda, Kazutoshi, Tomita, Daisaku.
Application Number | 20030074793 10/303460 |
Document ID | / |
Family ID | 15970721 |
Filed Date | 2003-04-24 |
United States Patent
Application |
20030074793 |
Kind Code |
A1 |
Toda, Kazutoshi ; et
al. |
April 24, 2003 |
Axial force controlling method and bearing apparatus
Abstract
In a bearing apparatus having a bearing and a shaft body, the
bearing being mounted to the shaft body such that the bearing fits
an outside of the shaft body, the bearing being prevented from
dropping off by holding a caulked portion against an outer end face
of an inner ring of the bearing, and the caulked portion being
formed by bending a cylindrical portion to be caulked of the shaft
body outward in a diameter direction, an axial force controlling
method controls an axial force applied to the bearing through the
caulked portion by setting a relationship between relative
positions in an axial direction of an end edge on an inner
periphery side of a chamfered portion formed at an inner peripheral
shoulder portion of the inner ring and a caulking starting point on
an inner periphery side of a cylindrical portion to be caulked.
Inventors: |
Toda, Kazutoshi;
(Tondabayashi-shi, JP) ; Ishii, Tomohiro;
(Yamatotakada-shi, JP) ; Mitarai, Tadashi;
(Kashiwara-shi, JP) ; Tomita, Daisaku;
(Kashiwara-shi, JP) |
Correspondence
Address: |
JORDAN AND HAMBURG LLP
122 EAST 42ND STREET
SUITE 4000
NEW YORK
NY
10168
US
|
Assignee: |
Koyo Seiko Co., Ltd.
Chuo-ku
JP
|
Family ID: |
15970721 |
Appl. No.: |
10/303460 |
Filed: |
November 25, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10303460 |
Nov 25, 2002 |
|
|
|
09562390 |
May 1, 2000 |
|
|
|
Current U.S.
Class: |
29/898.07 |
Current CPC
Class: |
Y10T 29/49682 20150115;
Y10T 29/49536 20150115; Y10T 29/497 20150115; F16C 43/04 20130101;
Y10T 29/49535 20150115; F16C 19/186 20130101; F16C 2326/02
20130101; B60B 27/0084 20130101; Y10T 29/49696 20150115; B60B 27/00
20130101; F16C 2240/40 20130101 |
Class at
Publication: |
29/898.07 |
International
Class: |
B21K 001/76; B23P
017/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 21, 1999 |
JP |
11-173989 |
Claims
What is claimed is:
1. An axial force controlling method for controlling an axial force
applied to a rolling bearing in a bearing apparatus having said
rolling bearing and a shaft body, said rolling bearing being
mounted to said shaft body such that said rolling bearing fits an
outside of said shaft body, said rolling bearing being prevented
from dropping off by holding a caulked portion against an outer end
face of an inner ring of said rolling bearing, and said caulked
portion being formed by bending a cylindrical portion to be caulked
on a free end side of said shaft body outward in a diameter
direction, wherein said method comprises the following steps for
controlling said axial force applied to said rolling bearing
through said caulked portion: a first step of setting a position
(first position) of an end edge on an inner periphery side of a
chamfered portion formed at an inner peripheral shoulder portion of
said inner ring; and a second step of setting a relationship
between relative positions on an axial direction of said first
position and a position (second position) of a caulking starting
point on an inner periphery side of said cylindrical portion to be
caulked.
2. An axial force controlling method according to claim 1, wherein
said second step is a step of positioning said second position on
an axially outside with respect to said first position.
3. An axial force controlling method according to claim 1, wherein
said second step is a step of axially aligning said second position
with respect to said first position.
4. An axial force controlling method according to claim 1, wherein
said second step is a step of positioning said second position on
an axially inside with respect to said first position.
5. An axial force controlling method according to claim 1 further
including a third step of setting a radial thickness of said
cylindrical portion to be caulked.
6. An axial force controlling method according to claim 1 further
including a fourth step of setting a hardness of said cylindrical
portion to be caulked.
7. An axial force controlling method according to claim 1, wherein
said second step is a step of obtaining an axial force greater than
a required axial force by plotting said axial direction in a
one-dimensional coordinate, defining said first position as an
origin point of said one-dimensional coordinate, setting a range of
a permissible position to which said second position can be moved
away from said first position at least one of axially inward or
outward according to said required axial force, and setting said
relationship between relative positions in said axial direction of
said first position and said second position in said range.
8. A bearing apparatus comprising: a rolling bearing; and a shaft
body, said rolling bearing being mounted to said shaft body such
that said rolling bearing fits an outside of said shaft body and
said shaft body having a cylindrical portion to be caulked on a
free end side of said shaft body, wherein said cylindrical portion
to be caulked of said shaft body is bent outward in a diameter
direction onto an outer end face of an inner ring to form a caulked
portion in a state in which a relationship between relative
positions in an axial direction of a caulking starting point on an
inner periphery side of said cylindrical portion and an end edge on
an inner periphery side of a chamfered portion formed at an inner
peripheral shoulder portion of said inner ring of said rolling
bearing, and an axial force is applied to said rolling bearing
through said caulked portion.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an axial force controlling
method for controlling an axial force applied to a rolling bearing
in a bearing apparatus having a shaft body, the rolling bearing
being mounted to the shaft body such that the rolling bearing fits
an outside of the shaft body, and the bearing apparatus.
[0003] 2. Description of the Related Art
[0004] A prior-art axial force controlling method will be described
by reference to FIGS. 5 to 7.
[0005] A bearing apparatus shown in FIG. 5 is a hub unit for a
driving wheel of a vehicle. The hub unit has a hub wheel 10 as a
shaft body and an angular ball bearing 12 which is mounted to a
shaft portion 11 of the hub wheel 10 such that the ball bearing 12
fits an outside of the shaft portion 11 and which is an example of
a rolling bearing of an inclined contact type. A free end of the
shaft portion 11 is caused to bulge and deformed outward in a
diameter direction by rolling caulking to form a caulked portion
13. The bearing 12 has an inner ring 12a, an outer ring 12b, a
plurality of balls 12c, and two snap cages 12d. In the bearing 12,
necessary preload is applied to the inner ring 12a by the caulked
portion 13 and the bearing 12 is prevented from dropping off from
the hub wheel 10.
[0006] Such a hub unit is mounted between a drive shaft 14 and a
shaft case 15 of the vehicle. In other words, the shaft portion 11
of the hub wheel 10 is spline-fitted with the drive shaft 14 and
connected to the drive shaft 14 by a nut 16 and an outer ring 12b
of the bearing 12 is connected to the shaft case 15 by a bolt
17.
[0007] In the shaft portion 11 of the hub wheel 10, a caulking jig
20 as shown in FIG. 7 is held against a cylindrical portion 11a to
be caulked on a free end side of the shaft portion 11 as shown by a
phantom line in FIG. 6 before caulking. Then, by rolling the
caulking jig 20 about a one-dot dashed line O at a constant angle
.alpha., the cylindrical portion 11a to be caulked is caused to
bulge and deformed radially outward, thereby forming the caulked
portion 13 held against an outer end face of the inner ring
12a.
[0008] In the above bearing apparatus, because the caulked portion
13 is held against the outer end face of the inner ring 12a in
order to bring the balls 12c into compressed states between the
inner ring 12a and the outer ring 12b, a force for detaching the
caulked portion 13 from the inner ring 12a in an axial direction
acts on the caulked portion 13 on the contrary. As a result, an
axially inward reaction force (hereafter defined as an axial force)
for resisting the above force is generated from the caulked portion
13.
[0009] It is known that control for properly maintaining the axial
force is necessary for ensuring a rolling property of the balls
12c.
[0010] In the prior-art axial force controlling method, the axial
force is controlled by merely caulking the caulked portion 13
firmly, adjusting a thickness of the caulked portion 13, or
adjusting applied pressure in caulking. However, it is not easy to
properly control the axial force by this method.
[0011] The present inventors have studied the axial force earnestly
and as a result, found the following point. There is a caulking
starting point on an inner periphery side of the cylindrical
portion 11a to be caulked of the shaft portion 11 in caulking the
cylindrical portion 11a on the outer end face of the inner ring 12a
and outward in the radial direction by using the caulking jig
20.
[0012] When an end edge on the inner periphery side of a chamfered
portion formed at an inner peripheral shoulder portion of the inner
ring 12a was defined as a point A, the caulking starting point was
defined as a point B, and a relationship between relative positions
of both the points A and B was changed, it was found that the axial
force applied to the outer end face of the inner ring 12a from the
caulked portion 13 varied.
SUMMARY OF THE INVENTION
[0013] Therefore, it is a main object of the present invention to
provide an axial force controlling method for properly and easily
control an axial force and a bearing apparatus according to the
method.
[0014] Other objects, features, and advantages of the invention
will become apparent from the following descriptions.
[0015] In an axial force controlling method of the present
invention for controlling an axial force applied to a rolling
bearing in a bearing apparatus having the rolling bearing and a
shaft body, the rolling bearing being mounted to the shaft body
such that the rolling bearing fits an outside of the shaft body,
the rolling bearing being prevented from dropping off by holding a
caulked portion against an outer end face of an inner ring of the
rolling bearing, and the caulked portion being formed by bending a
cylindrical portion to be caulked on a free end side of the shaft
body outward in a diameter direction, the method comprises the
following steps for controlling the axial force applied to the
rolling bearing through the caulked portion: a first step of
setting a position (first position) of an end edge on an inner
periphery side of a chamfered portion formed at an inner peripheral
shoulder portion of the inner ring; and a second step of setting a
relationship between relative positions on an axial direction of
the first position and a position (second position) of a caulking
starting point on an inner periphery side of the cylindrical
portion to be caulked, thereby controlling the axial force through
the caulked portion.
[0016] It is preferable that the second step is a step of
positioning the second position on an axially outside with respect
to the first position.
[0017] It is preferable that the second step is a step of axially
aligning the second position with respect to the first
position.
[0018] It is preferable that the second step is a step of
positioning the second position on an axially inside with respect
to the first position.
[0019] It is further preferable that the method includes a third
step of setting a radial thickness of the cylindrical portion to be
caulked.
[0020] It is further preferable that the method includes a fourth
step of setting a hardness of the cylindrical portion to be
caulked.
[0021] A bearing apparatus of the present invention comprises a
rolling bearing and a shaft body, the rolling bearing being mounted
to the shaft body such that the rolling bearing fits an outside of
the shaft body and the shaft body having a cylindrical portion to
be caulked on a free end side of the shaft body, wherein the
cylindrical portion to be caulked of the shaft body is bent outward
in a diameter direction onto an outer end face of an inner ring to
form a caulked portion in a state in which a relationship between
relative positions in an axial direction of a caulking starting
point on an inner periphery side of the cylindrical portion and an
end edge on an inner periphery side of a chamfered portion formed
at an inner peripheral shoulder portion of the inner ring of the
rolling bearing, and an axial force is applied to the rolling
bearing through-the caulked portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] These and other objects as well as advantages of the
invention will become clear by the following description of
preferred embodiments of the invention with reference to the
accompanying drawings, wherein:
[0023] FIG. 1 shows a sectional view of an essential portion of a
hub unit for a vehicle driving wheel controlled by an axial force
controlling method of an embodiment of the present invention and
shows a case in which a caulking starting point is positioned on an
axially outside of an end edge position on an inner periphery
side;
[0024] FIG. 2 corresponds to FIG. 1 and shows a case in which the
caulking starting point is axially aligned with the end edge
position on the inner periphery side;
[0025] FIG. 3 corresponds to FIG. 1 and shows a case in which the
caulking starting point is positioned on an axially inside of the
end edge position on the inner periphery side;
[0026] FIG. 4 shows a relationship between a position of the
caulking starting position and an axial force;
[0027] FIG. 5 is a vertical sectional side view of the hub unit for
the vehicle driving wheel;
[0028] FIG. 6 is an enlarged view of a caulked portion that is an
essential portion of FIG. 4; and
[0029] FIG. 7 is a step diagram for explaining a caulking form of
the caulked portion of FIG. 4.
[0030] In all these figures, like components are indicated by the
same numerals.
DETAILED DESCRIPTION OF THE INVENTION
[0031] An axial force controlling method according to a preferred
embodiment of the present invention and a bearing apparatus
according to the method will be described below by reference to the
drawings. In this embodiment, a hub unit for a vehicle driving
wheel is taken as an example of the bearing apparatus. Because a
basic structure of the hub unit is shown in FIG. 5, a detailed
description of it will be omitted.
[0032] By reference to FIGS. 1 to 3, the axial force controlling
method of the preferred embodiment of the invention will be
described. All of FIGS. 1 to 3 show a state before bending and
caulking a cylindrical portion 11a to be caulked of a shaft portion
11 outward in a diameter direction onto an outer end face of an
inner ring 12a. Illustration of a form after the caulking is
omitted.
[0033] In these drawings, a character A designates a position on an
axial direction of an end edge on an inner periphery side at a
chamfered portion at an inner peripheral shoulder portion of the
inner ring 12a of a rolling bearing 12 as a first position. In the
following description, this position will be referred to as an
origin point position A. A character B designates a position of a
caulking starting point on an inner periphery side of the
cylindrical portion 11a to be caulked as a second position.
[0034] The axial force controlling method of this embodiment
includes a first step of setting the origin point position A and a
second step of setting a relationship between relative positions in
an axial direction of the origin point position A and the caulking
starting position B as the steps for controlling an axial force
applied to the rolling bearing 12 through the caulked portion
13.
[0035] With regard to the above relationship between the relative
positions, the caulking starting point position B is positioned on
an axially outside with respect to the origin point position A in
FIG. 1, the caulking starting point position B and the origin point
position A are aligned with each other in the axial direction in
FIG. 2, and the caulking starting point position A is positioned on
an axially inside with respect to the origin point position A in
FIG. 3.
[0036] Here, the axial direction is plotted in a one-dimensional
coordinate, e.g., x, the origin point position A is defined as an
origin point of the one-dimensional coordinate x, and the caulking
starting point position B is defined as a coordinate point x on the
one-dimensional coordinate. As a result, the coordinate point x of
the caulking starting point position B is greater than 0 in the
case of FIG. 1, the coordinate point x of the caulking starting
point position B is equal to 0 in the case of FIG. 2, and the
coordinate point x of the caulking starting point position B is
less than 0 in the case of FIG. 3.
[0037] Therefore, if a thickness of the cylindrical portion 11a to
be caulked in a diameter direction is defined as t, x/t>0 in the
case of FIG. 1, x/t=0 in the case of FIG. 2, and x/t<0 in the
case of FIG. 3.
[0038] The present inventors measured the axial force according to
the settings of the relationship between the relative positions of
the origin point position A and the caulking starting point
position B in the respective cases of FIGS. 1 to 3 by experiment
and obtained results as shown in FIG. 4. A horizontal axis
designates x/t and a vertical axis designates the axial force (kgf)
respectively in FIG. 4.
[0039] In this experiment, hardness of the cylindrical portion 11a
to be caulked is varied among the case of FIG. 1, the case of FIG.
2, and the case of FIG. 3 to be low (16 to 18 HRC: hardness 1,
represented by a mark .diamond. in FIG. 4), middle (20 to 22 HRC:
hardness 2, represented by marks .quadrature. and .box-solid. in
FIG. 4), and high (26 to 28 HRC: hardness 3, represented by a mark
.DELTA. in FIG. 4).
[0040] With the hardnesses 1 and 3, the radial thickness t of the
cylindrical portion 11a to be caulked is maintained at a constant
value, i.e., 5 mm to carry out measurement.
[0041] With the hardness 2, two kinds of radial thicknesses t of
the cylindrical portion 11a to be caulked, i.e., 5 mm (.quadrature.
in FIG. 4) and 7 mm (.box-solid. in FIG. 4) are used to carry out
the measurement.
[0042] The measurement will be described below by reference to FIG.
4.
[0043] (1) The case of the relationship between the relative
positions in FIG. 1 (x/t>0):
[0044] To improve accuracy and reliability of the measurement of
the axial force, conditions of the measurement of the axial force
are as follows. {circle over (1)} The position of the caulking
starting point B is varied four times toward the outside in the
axial direction. {circle over (2)} The hardness of the cylindrical
portion 11a to be caulked is varied to be three kinds of
hardnesses, i.e., the hardness 1, the hardness 2, and the hardness
3 at the respective positions of the caulking starting point B.
{circle over (3)} With the hardness 2, the radial thickness t of
the cylindrical portion 11a to be caulked is varied to be two kinds
of thicknesses, i.e., 5 mm and 7 mm.
[0045] On the above conditions of the measurement, the axial force
was measured at the respective caulking starting point positions B.
These conditions of the measurement are similar in the following
case.
[0046] The measurement results on the above conditions of the
measurement are as shown in FIG. 4. In FIG. 4, variation of the
axial force is between a measurement upper line L1 and a
measurement lower line L2 and a downward slope toward the outside
in the axial direction in an area between both the lines L1 and L2
is large.
[0047] According to the above results, with any hardnesses of the
cylindrical portion 11a to be caulked, the axial force varies to be
smaller as the caulking starting point position B moves toward the
outside in the axial direction. Therefore, because the axial force
varies depending on the setting of the relationship between the
relative positions in the axial direction of the origin point
position A and the caulking starting point position B, it is
possible to properly and easily control the axial force applied to
the rolling bearing 12 through the caulked portion 13.
[0048] Because the axial force varies also when the radial
thickness t of the cylindrical portion 11a to be caulked is varied
to be 5 mm and 7 mm with the hardness 2, it is possible to further
properly control the axial force by setting the radial thickness t
of the cylindrical portion 11a as the third step.
[0049] Because the axial force varies also when the hardness of the
cylindrical portion 11a to be caulked is varied to be the hardness
1, the hardness 2, and the hardness 3 with the same relationship
between the relative positions, it is possible to further properly
control the axial force by setting the hardness as the fourth
step.
[0050] In this case of the hardness, the lower the hardness, the
greater the axial force became. The reason for this is considered
to be as follows. If the hardness of the cylindrical portion 11a to
be caulked is smaller, the cylindrical portion 11a can be caulked
easily and the inner ring 12a can be pushed axially inward to a
greater extent. As a result, the larger axial force is obtained.
Therefore, in order to increase the axial force, it is preferable
that the hardness of the cylindrical portion 11a to be caulked is
reduced.
[0051] Furthermore, the closer the caulking starting point position
B to the origin point position A, the greater the axial force
becomes.
[0052] (2) The case of the relationship between the relative
positions in FIG. 2 (x/t=0):
[0053] The conditions of the measurement in the case of this
relationship between the relative positions are similar to those in
the above (1) except that the caulking starting point position B is
aligned with the origin point position A.
[0054] In this case also, it is possible to control the axial force
by setting the relationship between the relative positions in the
axial direction of the origin point position A and the caulking
starting point position B.
[0055] Similarly to the above (1), it is possible to control the
axial force by setting the radial thickness t of the cylindrical
portion 11a to be caulked.
[0056] Similarly to the above (1), it is possible to control the
axial force by setting the hardness. In other words, when a
comparison was made between the hardness 1, the hardness 2, and the
hardness 3 of the cylindrical portion 11a to be caulked, the
greatest axial force was obtained with the hardness 1 and the axial
force with the hardness 2 was substantially equal to that with the
hardness 3 or slightly greater than that with the hardness 3 on
average. The reason for this is considered to be the same as that
in the above (1).
[0057] (3) The case of the relationship between the relative
positions in FIG. 3 (x/t<0):
[0058] The conditions of the measurement in the case of this
relationship between the relative positions are similar to those in
the above (1) except that the caulking starting point position B is
on the axially inside.
[0059] In this case also, the axial force varies according to the
setting of the relationship between the relative positions with any
hardness. Therefore, it is possible to control the axial force by
setting the relationship between the relative positions.
[0060] Similarly to the above (1), it is also possible to control
the axial force by setting the radial thickness t of the
cylindrical portion 11a to be caulked.
[0061] Furthermore, similarly to the above (1), it is also possible
to control the axial force by setting the hardness.
[0062] In the variation of the axial force shown in FIG. 4, a
downward slope toward the outside in the axial direction in the
axial force area between the measurement upper line L1 and the
measurement lower line L2 is large in the case of x/t>0 of the
above (1) and a downward slope toward the inside in the axial
direction in an axial force area between a measurement upper line
L3 and a measurement lower line L4 is small in the case of x/t<0
of the above (3).
[0063] The reason for this is that deformed volume due to caulking
of the cylindrical portion 11a to be caulked becomes large in the
case of the above (1) and as a result, the axial force reduces if
the applied pressure is constant.
[0064] If the minimum axial force (required axial force) required
to ensure the rolling property of the balls 12c of the rolling
bearing 12 is 2500 kgf, for example, x/t is in a range of
-0.15.ltoreq.x/t.ltoreq.0.05 for the respective hardnesses 1, 2,
and 3 from the graph in FIG. 4. If the radial thickness t of the
cylindrical portion 11a to be caulked is equal to 5 mm, for
example, -0.75.ltoreq.x.ltoreq.0.25, in other words, a maximum
permissible position to which the caulking starting point B of the
cylindrical portion 11a to be caulked can move axially inward from
the origin point position A is 0.75 mm in FIG. 3 and the maximum
permissible position to which the caulking starting point position
B of the cylindrical portion 11a to be caulked can move axially
outward from the origin point position A is 0.25 mm in FIG. 1.
Within this range, the required axial force of 2500 Kgf or more can
be obtained.
[0065] As pieced together from the above measurement results, the
closer the caulking starting point position B to the origin point
position A, the greater the axial force becomes, but the caulking
starting position B does not necessarily have to be aligned with
the origin point position A if the above-described axial force
required to ensure the rolling property of the balls 12c is
considered and the caulking starting position B may be separated
axially outward or axially inward from the origin point position A.
In this case, there are both axially outward and inward maximum
permissible separated distances, it is necessary to set the
caulking starting point position B within a range of the maximum
separated distances to control the axial force.
[0066] In order to obtain a necessary axial force with high
accuracy, it is preferable to properly separate the caulking
starting point position B axially outward or inward from the origin
point position A.
[0067] Furthermore, because the radial thickness of the cylindrical
portion 11a to be caulked is also related to the axial force, it is
preferable to consider the radial thickness in addition to the
axial position of the caulking starting point position B in
controlling the axial force.
[0068] Moreover, because the hardness of the cylindrical portion
11a to be caulked is related to the axial force, it is preferable
to consider the hardness in addition to the axial position of the
caulking starting point position B in controlling the axial
force.
[0069] In the above manner, according to the axial force
controlling method of the present embodiment, it is possible to
easily control the axial force such that the proper axial force can
be obtained basically by setting the relationship between the
relative positions.
[0070] The bearing apparatus to which the present invention is
applied is not limited to the hub wheel shown in the
above-described embodiment. The invention can be applied to control
of the axial force in every bearing apparatus having a rolling
bearing and a shaft body, the rolling bearing being mounted to the
shaft body such that the rolling bearing fits an outside of the
shaft body, the rolling bearing being prevented from dropping off
by holding the caulked portion against the outer end face of the
inner ring of the rolling bearing, the caulked portion being formed
by bending the cylindrical portion to be caulked on the free end
side of the shaft body outward in the diameter direction.
[0071] Although the above hardness has a range of 2 HRC, this is
variation caused by a heat treatment and this amount of variation
is generated even in a treatment of the same lot.
[0072] The smaller the hardness, the larger the axial force becomes
from the above measurement results only. However, a lower limit of
the hardness is 16 HRC.
[0073] By the above axial force controlling method, the bearing
apparatus according to the embodiment has the rolling bearing 12
and the shaft body 11, the rolling bearing 12 being mounted to the
shaft body 11 such that the rolling bearing 12 fits the outside of
the shaft body 11, and the shaft body 11 having the cylindrical
portion 11a to be caulked on the free end side of the shaft body
11. The cylindrical portion 11a to be caulked of the shaft body 11
is bent outward in the diameter direction onto the outer end face
of the inner ring 12a to form the caulked portion 13 in a state in
which the relationship between the relative positions in the axial
direction of the caulking starting point position B on the inner
periphery side of the cylindrical portion 11a and the position A of
the end edge on the inner periphery side of the chamfered portion
formed at the inner peripheral shoulder portion of the inner ring
of the rolling bearing is set. In this manner, in the case of this
bearing apparatus, the axial force is applied to the rolling
bearing 12 through the caulked portion 13 and it is possible to
control the axial force applied to the rolling bearing 12 by
setting the relationship between the relative positions.
[0074] While there has been described what is at present considered
to be preferred embodiments of this invention, it will be
understood that various modifications may be made therein, and it
is intended to cover in the appended claims all such modifications
as fall within the true spirit and scope of this invention.
* * * * *