Rotary shafts – gudgeons – housings – and flexible couplings for ro – Coupling accommodates drive between members having... – Coupling transmits torque via radially spaced ball
Reexamination Certificate
2000-11-30
2003-10-21
Browne, Lynne H. (Department: 3679)
Rotary shafts, gudgeons, housings, and flexible couplings for ro
Coupling accommodates drive between members having...
Coupling transmits torque via radially spaced ball
C384S544000, C464S175000
Reexamination Certificate
active
06634951
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a driving wheel bearing unit which comprises a drive train of a motor vehicle. In particular, the prevent invention relates to a driving wheel bearing unit in which a wheel bearing for supporting a driving wheel of a motor vehicle is integrated with a constant velocity joint that establishes coupling with a driving shaft for transmitting power to the driving wheel.
2. Description of the Related Art
As shown in
FIGS. 9 and 10
, this type of wheel bearing unit includes a driving shaft
1
which is coupled at its inner end to a differential
3
via a slide type constant velocity joint
2
and at its outer end to a wheel bearing
4
via a rigid type constant velocity joint
14
. Here, the inner end of the driving shaft
1
refers to the end on the inside when viewed in the direction of width of a car body (the right sides in
FIGS. 1-6
,
9
, and
10
). Then, the outer end of the driving shaft
1
refers to the end on the outside when viewed in the direction of width of the car body (the left sides in
FIGS. 1-6
,
9
, and
10
). The wheel bearing
4
comprises an external member
11
and an internal member
13
. The external member
11
is fixed to a knuckle
10
which is supported by the car body via a suspension system. The internal member
13
is rotatably supported inside the external member
11
via two rows of rolling elements
12
a
and
12
b
. An outside joint member
15
of the constant velocity joint
14
is coaxially coupled to and integrated with the internal member
13
.
The knuckle
10
has a circular mounting hole
10
a
drilled therethrough in the car width direction. The external member
11
has a cylindrical outer periphery
11
a
at one end and a flange
11
b
at the other. The outer periphery
11
a
of the external member
11
is fitted to the mounting hole
10
a
in the knuckle
10
. Then, mounting bolts
21
are inserted through bolt holes in the knuckle
10
from inside, and screwed into a plurality of screw holes
11
c
formed in the flange
11
b
. This fastens the knuckle
10
and the external member
11
to each other. Outer races
11
d
and
11
e
for the two rows of rolling elements
12
a
and
12
b
are formed in the inner periphery of the external member
11
. Of two inner races corresponding to these outer races, one
13
c
is formed in the outer periphery of the internal member
13
, and the other
15
a
is formed in the outer periphery of the outside joint member
15
of the constant velocity joint
14
.
The constant velocity joint
14
is chiefly composed of the outside joint member
15
, an inside joint member
16
, a cage
17
, a plurality of torque transmission balls
18
, and a boot
19
. The outside joint member
15
consists of a bowl-like mouth part and a shaft-like stem part. The mouth part has a spherical inner periphery provided with six guide grooves which extend along the axial direction at regular circumferential intervals. Formed on the stem part are a shoulder portion
15
b
extending perpendicularly to the axis, a press-in portion
15
c
having a cylindrical outer periphery, a spline shaft portion
15
d
, and a caulking portion
15
e
. These portions
15
b
-
15
e
are arranged in series on the shaft-end side of the above-described inner race
15
a
. The inside joint member
16
has a spherical outer periphery provided with six guide grooves which extend along the axial direction at regular circumferential intervals. The outer end of the driving shaft
1
is spline-connected to this inside joint member
16
. The guide grooves in the outside joint member
15
and the guide grooves in the inside joint member
16
are paired to form six ball tracks, in which six torque transmission balls
18
are arranged, i.e. one in each ball track, to make torque transmission between both the joint members. The cage
17
for retaining the torque transmission balls
18
is interposed between the inner periphery of the outside joint member
15
and the outer periphery of the inside joint member
16
. The boot
19
of accordion form is fixed at its larger end to the outer periphery of the mouth part of the outside joint member
15
. The smaller end of the boot
19
is fixed to the outer periphery of the driving shaft
1
.
A flange
13
a
intended for wheel mounting is integrally formed on the outer periphery of the internal member
13
. Hub bolts
22
are fixed to the flange
13
a
at a plurality of positions along the circumferential direction. The internal member
13
is shaped like a hollow cylinder, having a cylindrical hole portion and a spline hole portion
13
b
to be fitted to the outside joint member
15
. The press-in portion
15
c
of the outside joint member
15
is pressed into the inner periphery of the internal member
13
, and the spline shaft portion
15
d
of the outside joint member
15
is spline-connected to the spline hole portion
13
b
of the internal member
13
. Then, with the shoulder portion
15
b
pressed against the inner end of the internal member
13
, the caulking portion
15
e
is caulked with the outer end of the internal member
13
to integrate the internal member
13
and the outside joint member
15
with each other.
In the wheel bearing unit described above, the maximum outer diameter of the constant velocity joint
14
, especially of the boot
19
, is greater than the inner diameter of the mounting hole
10
a
in the knuckle
10
. Accordingly, there has been a necessity to assemble the constant velocity joint
14
and the wheel bearing
4
on carmaker side, meaning poor workability. Besides, when the wheel bearing
4
and constant velocity joint
14
mounted on a car body are to undergo inspections, repairs, and the like, and when the constant velocity joint is to undergo boot replacement in particular, it has been needed that the entire unit including the knuckle
10
be dismounted from the car body, resulting in poor workability.
SUMMARY OF THE INVENTION
An object of the present invention is to facilitate the disassembly, assembly, and other works on a driving wheel bearing unit.
The present invention has solved the foregoing problem by rendering the diameter of the constant velocity joint across its maximum diameter portion equal to or smaller than the diameter of the external member across the fitting surface thereof.
In general, the maximum outer diameter portion of a boot attached to the outer periphery of the outside joint member makes the maximum diameter portion of the constant velocity joint. Therefore, when the diameter of this boot's maximum outer diameter portion is set to be equal to or smaller than the diameter of the external member across the fitting surface, it becomes possible to pass the entire constant velocity joint through a mating member to be fitted to the fitting surface of the external member, i.e., the mounting hole in the knuckle.
According to the present invention, it becomes possible to mount a wheel bearing and a constant velocity joint to a knuckle after assembly, with an improvement in workability. For example, when the wheel bearing and the constant velocity joint are mounted to a car body, their preassembly can be inserted from outside the car body to a mounting hole in the knuckle for mounting. When they are dismounted from the car body, the fastening between the external member and the knuckle can be released to allow the unitary extraction of the wheel bearing and the constant velocity joint from the mounting hole in the knuckle. This facilitates works including inspections and repairs.
More specifically, a driving wheel bearing unit is provided comprising: a wheel bearing including an external member having an outer periphery provided with a mounting flange for car-body mounting and a fitting surface, and an inner periphery provided with two outer races, and an internal member rotatably arranged inside the external member via a rolling element, the internal member having an outer periphery provided with a race and a wheel mounting flange for mounting a wheel; and a constant veloc
Hozumi Kazuhiko
Ohtsuki Hisashi
Ozawa Masahiro
Sahashi Koji
Sone Keisuke
Arent Fox Kintner & Plotkin & Kahn, PLLC
NTN Corporation
Thompson Kenneth
LandOfFree
Driving wheel bearing unit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Driving wheel bearing unit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Driving wheel bearing unit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3164117