U.S. patent application number 09/902230 was filed with the patent office on 2002-01-17 for bearing apparatus.
This patent application is currently assigned to Koyo Seiko Co., Ltd.. Invention is credited to Kashiwagi, Shinichirou, Kawatani, Teruyuki, Takahashi, Kenji, Toda, Kazutoshi, Wakisaka, Teruyuki.
Application Number | 20020006239 09/902230 |
Document ID | / |
Family ID | 18711046 |
Filed Date | 2002-01-17 |
United States Patent
Application |
20020006239 |
Kind Code |
A1 |
Toda, Kazutoshi ; et
al. |
January 17, 2002 |
Bearing apparatus
Abstract
A bearing is mounted to a hollow shaft provided to a hub wheel.
A shaft end of the hollow shaft is deformed radially outward and
caulked to an outer end face of an inner ring of the bearing.
Between a first area in which a spline portion is formed and a
second area in which a caulked portion is formed between a bending
starting point for bending the shaft end radially outward and an
end face of the shaft end on an inner peripheral face of the hollow
shaft, a third area for suppressing deformation of the inner
peripheral face of the hollow shaft caused by the caulking is
formed. The third area cushions deformation in the first area.
Inventors: |
Toda, Kazutoshi; (Osaka,
JP) ; Wakisaka, Teruyuki; (Nara, JP) ;
Takahashi, Kenji; (Nara, JP) ; Kawatani,
Teruyuki; (Nara, JP) ; Kashiwagi, Shinichirou;
(Osaka, JP) |
Correspondence
Address: |
Jordan and Hamburg
122 East 42nd Street
New York
NY
10168
US
|
Assignee: |
Koyo Seiko Co., Ltd.
|
Family ID: |
18711046 |
Appl. No.: |
09/902230 |
Filed: |
July 10, 2001 |
Current U.S.
Class: |
384/537 ;
384/544 |
Current CPC
Class: |
Y10T 29/49535 20150115;
F16D 2001/103 20130101; F16D 1/108 20130101; Y10T 29/49682
20150115; F16C 19/186 20130101; F16C 2326/02 20130101; Y10T
29/49696 20150115; B60B 27/0026 20130101; B60B 27/0094 20130101;
B60B 27/00 20130101; B60B 27/0005 20130101; F16C 43/04 20130101;
B60B 27/0084 20130101; F16C 35/0635 20130101; Y10T 29/49536
20150115; Y10T 29/49679 20150115 |
Class at
Publication: |
384/537 ;
384/544 |
International
Class: |
F16C 043/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 17, 2000 |
JP |
P2000-215658 |
Claims
What is claimed is:
1. A bearing apparatus comprising: a hollow shaft body; and a
rolling bearing mounted to an outer peripheral face of said shaft
body, wherein a shaft end of said shaft body is deformed radially
outward and caulked to an outer end face of an inner ring provided
to said rolling bearing, and said shaft body has on an inner
peripheral face thereof a first area in which a spline portion in
an axial direction is formed, a second area between a bending
starting point for bending said shaft end of said shaft body
radially outward and an end face of said shaft body, and a third
area between said first area and said second area for suppressing
deformation of said inner peripheral face of said shaft body caused
by said caulking.
2. The bearing apparatus according to claim 1, wherein said rolling
bearing is a double row angular contact ball bearing with vertex of
contact angles outside of bearing.
3. The bearing apparatus according to claim 1, wherein said third
area is set according to the following expression
(1):(X1/X2)>(y1/y2) (1)where X1 is an axial distance from a
position of a caulking side end portion of said first area to said
bending starting point for bending said shaft end of said shaft
body radially outward, X2 is an axial distance from said bending
starting point to a caulking side outer end face of said inner
ring, y1 is a difference between an outside diameter and a pitch
diameter of said first area, and y2 is a difference between an
outside diameter and an inside diameter of said shaft end of said
shaft body.
4. A bearing apparatus according to claim 3, wherein an inner
peripheral edge portion of a caulking side outer end face of said
inner ring is chamfered with a quarter of a circumference of a
radius of curvature from a center and a point of intersection of a
radial line from said center and said inner peripheral edge portion
is said bending starting point.
5. A vehicle hub unit comprising a hub wheel and a double row
angular contact ball bearing with vertex of contact angles outside
of baring, wherein said hub wheel includes a hollow shaft body in
which a drive shaft of a vehicle is inserted, said shaft body
including a small-diameter outer peripheral face and a
large-diameter outer peripheral face, said angular contact ball
bearing includes a first inner ring having a single race fitted
over said small-diameter outer peripheral face of said shaft body,
a single outer ring having two rows of races, a plurality of balls
disposed in two rows, and a second inner ring having two cages and
formed of said large-diameter outer peripheral face of said hollow
shaft, and said shaft body has a shaft end deformed radially
outward and caulked to an outer end face of said inner ring of said
angular contact ball bearing and has on an inner peripheral face
thereof a first area in which a spline portion in an axial
direction is formed, a second area between a bending starting point
for bending said shaft end of said shaft body radially outward and
an end face of said shaft body, and a third area between said first
area and said second area for suppressing deformation of said inner
peripheral face of said shaft body caused by said caulking
6. The vehicle hub unit according to claim 5, wherein said third
area is set according to the following expression
(1):(X1/X2)>(y1/y2) (1)where X1 is an axial distance from a
position of a caulking side end portion of said first area to said
bending starting point for bending said shaft end of said shaft
body radially outward, X2 is an axial distance from said bending
starting point to a caulking side outer end face of said first
inner ring, y1 is a difference between an outside diameter and a
pitch diameter of said first area, and y2 is a difference between
an outside diameter and an inside diameter of said shaft end of
said shaft body.
7. The vehicle hub unit according to claim 6, wherein an inner
peripheral edge portion of said caulking side outer end face of
said first inner ring is chamfered with a quarter of a
circumference of a radius of curvature from a center and a point of
intersection of a radial line from said center and said inner
peripheral edge portion is said bending starting point.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a bearing apparatus such as
a vehicle hub unit in which a rolling bearing is mounted to a shaft
body.
[0003] 2. Description of the Related Art
[0004] A vehicle hub unit will be described. A rolling bearing is
mounted to an outer periphery of a shaft body of a hub wheel. A
shaft end of the shaft body is bulged and deformed radially outward
by rolling caulking to be a caulked portion. This caulked portion
is caulked to an outer end face of an inner ring of the bearing to
thereby apply a pre-load to the bearing and to prevent coming off
of the bearing.
[0005] The shaft body of the hub wheel has a hollow structure such
that a drive shaft can be inserted into the shaft body. For spline
fitting with the drive shaft, an inner periphery of the shaft body
has spline portions.
[0006] The spline portions are formed to be substantially adjacent
to the caulked portion of the shaft end and to be formed long in an
axial direction so as to mechanically connect the inner periphery
of the shaft body and the drive shaft with necessary strength.
[0007] Therefore, the spline portions are liable to be deformed
radially inward to such a degree as to obstruct insertion of the
drive shaft into the shaft body by force applied radially outward
to the shaft end in caulking for forming the caulked portion.
SUMMARY OF THE INVENTION
[0008] Therefore, it is a main object of the present invention to
provide a bearing apparatus in which a spline portion of an inner
periphery of a shaft body is less liable to be deformed by caulking
and high accuracy of the spline portion in the shaft body can be
maintained.
[0009] Other objects, features, and advantages of the invention
will become clear by the following description.
[0010] To put it briefly, the bearing apparatus of the invention
includes a hollow shaft body and a rolling bearing mounted to an
outer peripheral face of the shaft body; wherein a shaft end of the
shaft body is deformed radially outward and caulked to an outer end
face of an inner ring provided to the rolling bearing and the shaft
body has on an inner peripheral face thereof a first area in which
a spline portion in an axial direction is formed, a second area
between a bending starting point for bending the shaft end of the
shaft body radially outward and an end face of the shaft body, and
a third area between the first area and the second area for
suppressing deformation of the inner peripheral face of the shaft
body caused by the caulking.
[0011] According to the invention, even if the spline portion is
formed to be axially long on the inner periphery of the hollow
shaft body so as to be mechanically connected to a spline portion
on an outer periphery of a drive shaft, because the third area is
provided between the first area and the second area, the first area
does not directly receive an influence of radially outward
deformation of the shaft end by caulking for forming the caulked
portion. As a result, it is possible to maintain high accuracy of
the spline portion and the first area is not deformed to such a
degree as to obstruct insertion of the drive shaft.
[0012] In the invention, the third area is preferably set according
to the following expression (1):
(X1/X2)>(y1/y2) (1)
[0013] where
[0014] X1 is an axial distance from a position of a caulking side
end portion of the first area to the bending starting point for
bending the shaft end of the shaft body radially outward, X2 is an
axial distance from the bending starting point to a caulking side
outer end face of the inner ring, y1 is a difference between an
outside diameter and a pitch diameter of the first area, and y2 is
a difference between an outside diameter and an inside diameter of
the shaft end of the shaft body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] 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,
[0016] wherein:
[0017] FIG. 1 is a vertical sectional view of a hub unit according
to the preferred embodiment of the present invention in a state
before a hollow shaft of a hub wheel is caulked;
[0018] FIG. 2 is a vertical side sectional view of the hub unit
according to the preferred embodiment of the invention in a state
after the hollow shaft of the hub wheel is caulked;
[0019] FIG. 3 is an essential portion enlarged sectional view of
spline-fitted portions of an inner periphery of a shaft body of the
hub wheel and an outer periphery of a drive shaft in the hub
unit;
[0020] FIG. 4 is an essential portion enlarged plan view of
spline-fitted portions of the inner periphery of the shaft body of
the hub wheel and the outer periphery of the drive shaft in the hub
unit; and
[0021] FIG. 5 is an enlarged sectional view of a periphery of an
inner ring of a bearing and a shaft end of the hollow shaft in the
hub unit.
[0022] In all these figures, like components are indicated by the
same numerals.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0023] A preferred embodiment of the present invention will be
described with reference to FIGS. 1 to 5. Here, a vehicle hub unit
is taken as an example of a bearing apparatus. However, balls and
the like are not shown in FIG. 5 for ease of illustration.
[0024] The hub unit 10 includes a hub wheel 11 and a bearing 12.
The bearing 12 is a double row angular contact ball bearing with
vertex of contact angles outside of bearing as an example of a
rolling bearing of a diagonal contact type.
[0025] The hub wheel 11 includes a flange 13 which is in a radially
outward orientation and to which a wheel (not shown) is mounted and
a hollow shaft 14.
[0026] The bearing 12 includes one inner ring 15 fitted over a
small-diameter outer peripheral face of the hollow shaft 14 and
having a single race, a single outer ring 16 having two rows of
races, a plurality of balls 17 disposed in two rows, and two snap
cages 18. As the inner ring 15, an inner ring of a general single
row angular contact ball bearing is used as it is.
[0027] In the bearing 12, a large-diameter outer peripheral face of
the hollow shaft 14 is used as the other inner ring.
[0028] The flange 19 is provided to an outer periphery of the outer
ring 16 in the radially outward orientation.
[0029] A shaft end 14a of the hollow shaft 14 is caulked to a
caulking side outer end face of the inner ring 15 from the state in
FIG. 1 to the state in FIG. 2. As a result of this caulking, the
shaft end 14a becomes a caulked portion.
[0030] In a caulked state in FIG. 2, the hub unit 10 is mounted
between a drive shaft 20 and a shaft case 21 of a vehicle.
[0031] In other words, the hollow shaft 14 of the hub wheel 11 is
spline-fitted over the drive shaft 20 and connected to the drive
shaft 20 through a nut 22. The flange 19 of the outer ring 16 of
the bearing 12 is connected to the shaft case 21 through a bolt 23
so as not to rotate.
[0032] Here, a reference numeral 14b designates a spline portion
formed on an inner periphery of the hollow shaft 14 and a reference
numeral 20a designates a spline portion formed on an outer
periphery of the drive shaft 20. Through both the spline portions
14b and 20a, the spline fitting is carried out.
[0033] A fitted state of the spline portions 14b of the hollow
shaft 14 and the spline portions 20a of the drive shaft 20 is as
shown in FIGS. 3 and 4. In other words, the respective spline
portions 14b and 20a are spaced uniformly in circumferential
directions and are in involute shapes. In this case, shapes of both
the spline portions 14b and 20a are not limited to the involute
shapes but may be other shapes.
[0034] The spline portions 14b of the hollow shaft 14 are inclined
in the circumferential direction. One sides of the spline portions
14b in the circumferential direction are in contact with one sides
of the spline portions 20a of the drive shaft 14 in the
circumferential direction while the other sides of the spline
portions 14b in the circumferential direction are in contact with
the other sides of the spline portions 20a in the circumferential
direction.
[0035] By reference to FIG. 5, features of the present embodiment
will be described.
[0036] In the hollow shaft 14, a spline portion forming area (first
area) 141 in which the spline portions 14b are formed and a caulked
portion forming area (second area) 142 in which the caulked portion
14a is formed are formed.
[0037] Between both the areas 141 and 142, a cushioning area (third
area) 143 for suppressing deformation of the inner peripheral face
of the hollow shaft 14 caused by caulking of the shaft end 14a of
the hollow shaft 14 is provided.
[0038] Therefore, influence of caulking of the shaft end 14a of the
hollow shaft 14 on the first area 141 is cushioned by the third
area 143. As a result, deformation of the first area 141 due to the
caulking is alleviated or suppressed.
[0039] Thus, high accuracy of the spline portions 14b in the first
area 141 can be maintained even in the caulking and such a degree
of deformation of the spline portions 14b as to obstruct insertion
of the drive shaft 20 can be prevented.
[0040] This will be described more specifically.
[0041] The first area 141 is an area between axially opposite end
faces of the spline portions 14b formed on the inner periphery of
the hollow shaft 14 and a caulking side end face on a pitch circle
line of the spline portion 14b is defined as a caulking side end
portion A of the first area 141.
[0042] The second area 142 is an area from a bending starting point
B of the shaft end 14a of the hollow shaft 14 to an end face of the
shaft end 14a. Here, an inner peripheral edge portion 15a of a
caulking side outer end face of the inner ring 15 is chamfered
round, e.g., with a quarter of a circumference of a radius of
curvature X2 from a center O. A point of intersection of a radial
line from the center O and the inner peripheral edge portion 15a is
defined as the bending starting point B.
[0043] The third area 143 is an area between the caulking side end
portion A and the bending starting point B.
[0044] Here, if a difference between an outside diameter Do of the
hollow shaft 14 and a pitch diameter Dp of the spline portion 14b
is y1, a difference between the outside diameter Do and an inside
diameter Di of the hollow shaft 14 is y2, an axial distance
(corresponding to an axial length of the third area 143) from the
caulking side end portion A of the spline portion 20b to the
bending starting point B is X1, and an axial distance from the
bending starting point B to the caulking side outer end face of the
inner ring 15 is X2, a position of the third area 143 is set
according to the following expression (1).
(X1/X2)>(y1/y2) (1)
[0045] Setting the position of the third area 143 by using the
above expression (1) is preferable because production of the hollow
shaft 14, i.e., settings of positions in which the spline portions
are formed and the shaft end which will be the caulked portion and
the like are easy.
[0046] A ground for the above expression (1) will be described. The
following expression (2) is obtained by transforming the expression
(1).
X1/X2)>(y1/y2) (1)
[0047] Here, X2 is the axial distance from the bending starting
point B to the caulking side outer end face of the inner ring 15.
This is based on setting the axial length X1 of the third area 143
at a large value because the influence of deformation in caulking
the shaft end 14a of the hollow shaft 14 on the first area 141
becomes large when the radius of curvature of chamfering of the
inner peripheral edge portion 15a of the inner ring 15 becomes
large or when a ratio between y2 and y1, i.e., a ratio between wall
thicknesses of the first and second areas 141 and 142 becomes
large.
[0048] The invention can be similarly applied to a vehicle hub unit
having a hollow shaft with a bottom in an axial direction. The
invention can be similarly applied to a vehicle hub unit for a
vehicle follower wheel.
[0049] 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.
* * * * *