U.S. patent application number 12/749053 was filed with the patent office on 2010-09-23 for knuckle hub assembly and method for making same.
Invention is credited to Daniel Brinker, Robert Veldman.
Application Number | 20100236069 12/749053 |
Document ID | / |
Family ID | 31989894 |
Filed Date | 2010-09-23 |
United States Patent
Application |
20100236069 |
Kind Code |
A1 |
Brinker; Daniel ; et
al. |
September 23, 2010 |
KNUCKLE HUB ASSEMBLY AND METHOD FOR MAKING SAME
Abstract
A knuckle hub assembly (10) and a method for manufacturing same
whereby brake run out is produced includes a knuckle (12), a
bearing (28) press fit into the knuckle (12), and a wheel hub (14)
coupled to the bearing (28) and rotatable with respect to the
knuckle (12). The wheel hub (14) has a flange surface (34) having a
relief channel (60) formed therein. A plurality of wheel studs (44)
are press fit into bolt opening (42) formed in the relief channel
(60). This arrangement provides a flat flange surface (34) for
mating with a rotor (42) to minimize brake run out. The knuckle hub
assembly (10) is mounted into a floating tool for finish turning of
the flange surface (34) to provide minimal run out and maximum
flatness.
Inventors: |
Brinker; Daniel; (Troy,
MI) ; Veldman; Robert; (Brighton, MI) |
Correspondence
Address: |
DOBRUSIN & THENNISCH PC
29 W LAWRENCE ST, SUITE 210
PONTIAC
MI
48342
US
|
Family ID: |
31989894 |
Appl. No.: |
12/749053 |
Filed: |
March 29, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11998865 |
Nov 30, 2007 |
7716833 |
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12749053 |
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11012074 |
Dec 14, 2004 |
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11998865 |
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10658861 |
Sep 9, 2003 |
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11012074 |
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10016589 |
Dec 14, 2001 |
6634266 |
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10658861 |
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09414113 |
Oct 8, 1999 |
6485109 |
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10016589 |
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60136535 |
May 28, 1999 |
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Current U.S.
Class: |
29/894.361 |
Current CPC
Class: |
B62D 7/18 20130101; Y10T
29/49535 20150115; F16D 2065/1384 20130101; B60B 27/00 20130101;
Y10T 29/49536 20150115; F16D 65/12 20130101; B23B 5/02 20130101;
Y10T 29/49904 20150115 |
Class at
Publication: |
29/894.361 |
International
Class: |
B21D 53/26 20060101
B21D053/26 |
Claims
1. A method for manufacturing a knuckle and hub assembly for a
vehicle comprising the steps of: providing a wheel hub having a
flange portion with an outer flange surface and an inner flange
surface; securing a plurality of wheel bolts to the flange portion
of the wheel hub; connecting a knuckle component to the wheel hub
to form the knuckle and hub assembly; clamping the knuckle and hub
assembly without attachment to the vehicle; and refinishing the
outer flange surface and the inner flange surface of the knuckle
and hub assembly to minimize run-out while the knuckle and hub
assembly is clamped without attachment to a vehicle.
2. The method of claim 1 wherein the knuckle component is
stationary and the wheel hub rotates during the refinishing of the
knuckle and hub assembly.
3. The method of claim 2 wherein the refinishing of the outer
flange and the inner flange surface reduces the run-out to 14
micrometers or less.
4. The method of claim 2 wherein the refinishing of the outer
flange surface and the inner flange surface such that the
co-planarness of the outer flange surface and the inner flange
surface is 20 micrometers or less.
5. The method of claim 1 wherein a clamping fixture clamps the
knuckle and hub assembly during the refinishing of the outer flange
surface and the inner flange surface.
6. The method of claim 1 wherein a lathe refinishes the outer
flange surface and the inner flange surface.
7. The method of claim 6 further comprising: rotating the knuckle
and hub assembly with respect to the lathe during the refinishing
of the knuckle and hub assembly.
8. The method of claim 1 wherein the wheel hub has a relief channel
disposed between the inner flange surface and the outer flange
surface.
9. A method for manufacturing a knuckle and hub assembly
comprising: providing a wheel hub having a flange portion with an
outer flange surface and an inner flange surface; connecting a
knuckle component to the wheel hub to form the knuckle and hub
assembly; clamping the knuckle component of the knuckle and hub
assembly without attachment to the vehicle; and rotating the wheel
hub of the knuckle and hub assembly to finish the outer flange
surface and the inner flange surface of the knuckle and hub
assembly to minimize run-out while the knuckle and hub assembly is
clamped without attachment to a vehicle.
10. The method of claim 9 wherein the knuckle and hub assembly is
finished such that the outer flange surface and the inner flange
surface have a co-planarness within 20 micrometers.
11. The method of claim 10 further comprising the step of: securing
the wheel bolts to the wheel hub prior to finishing the outer
flange surface and the inner flange surface.
12. The method of claim 11 wherein the knuckle component has a
plurality of apertures formed therein for attachment of the knuckle
component to the vehicle.
13. The method of claim 12 further comprising the step of: forming
a relief channel in said flange portion between the inner flange
surface and the outer flange surface, the relief channel having a
plurality of wheel bolt receiving apertures formed therein for
receipt of the wheel bolts therethrough.
14. The method of claim 9 wherein the knuckle component remains
secured to the wheel hub during the finishing of the outer flange
surface and the inner flange surface.
15. The method of claim 10 wherein the knuckle component is held
stationary during finishing of the knuckle and hub assembly.
16. The method of claim 15 wherein a fixture having a lathe
refinishes the outer flange surface and the inner flange
surface.
17. The method of claim 15 wherein the wheel hub rotates with
respect to the lathe.
18. A method for manufacturing a knuckle and hub assembly for a
vehicle comprising: providing a wheel hub having a neck portion and
a flange portion, the flange portion having a flange face with an
inner flange surface and an outer flange surface, and a relief
channel disposed between the inner flange surface and the outer
flange surface; forming a plurality of bolt receiving apertures in
the relief channel; attaching a plurality of wheel bolts on the
wheel hub; assembling the wheel hub and a knuckle to form the
knuckle hub assembly; clamping the knuckle into a fixture
incorporating a lathe; final finishing the inner flange surface and
the outer flange surface to reduce lateral run-out wherein the
inner flange surface and the outer flange surface have a flatness
of at least 20 micrometers.
19. The method for manufacturing the method of claim 18 wherein the
knuckle is held stationary and the wheel hub is rotated during the
final finishing of the outer flange surface and the inner flange
surface.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 11/998,865, filed on Nov. 30, 2007, which is a
continuation of U.S. patent application Ser. No. 11/012,074, filed
on Dec. 14, 2004, which is a continuation of U.S. patent
application Ser. No. 10/658,861, filed Sep. 9, 2003, now abandoned.
The '861 patent application is a continuation of U.S. patent
application Ser. No. 10/016,589, filed Dec. 14, 2001, now U.S. Pat.
No. 6,634,266, which is a continuation of U.S. patent application
Ser. No. 09/414,113 filed Oct. 8, 1999, now U.S. Pat. No.
6,485,109. The '113 patent application claims the benefit of U.S.
Provisional Patent Application Ser. No. 60/136,535, filed May 28,
1999. Each patent and patent application identified above is hereby
incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The present invention relates generally to motor vehicle
wheel end components. More particularly, the present invention
relates to a knuckle/hub assembly having a unique assembly and
manufacturing process for reducing lateral run-out and a unique
apparatus for machining the rotor-mounting flange surface of the
wheel hub.
BACKGROUND ART
[0003] Most motor vehicles today include disc brake systems for the
front axle wheel assemblies and many further include disc brakes at
the rear axle position. The disc brake rotor is a circular metal
disc having opposed braking surfaces that are clamped by brake pads
carried by a brake caliper to exert a braking effect. The wheel hub
typically incorporates an anti-friction wheel bearing assembly in
which one race of the bearing is coupled to the vehicle suspension
and the other rotationally mounts the wheel hub, the brake rotor
and wheel. Ordinarily, the rotating components of the rotor and hub
assembly are manufactured separately and assembled together. This
enables the brake rotor to be serviced and replaced if necessary
during use. Moreover, the desired material characteristics for a
brake rotor and the hub components are different. Although efforts
to integrate these components have been proposed, such an approach
has not found widespread acceptance.
[0004] In order to enhance performance of the braking system, it is
desired to carefully and accurately control the dimensional
characteristics of the rotor braking surfaces as the rotor rotates.
The thickness variation of the disc and the lateral run-out or
lateral deflection of the surfaces as they rotate need to be held
to minimum tolerances. Similarly, the radial run-out of the outer
edges of the braking surfaces need to be controlled to ensure that
the brake pads engage as much of the available rotor braking
surface as possible without overlapping the edges of the rotor
which gives rise to brake run-out. However, manufacturers have
faced difficulties in achieving enhanced control over these
tolerances due to the influence of several factors.
[0005] Most efforts to date have focused on decreasing run-out by
controlling the dimensional characteristics of the rotor, and,
therefore, the relationship of the rotor surface to the wheel hub
flange or surface. However, despite the fact that the tolerances
and dimensional characteristics of the rotors have improved,
performance and run-out problems still exist. These run-out
problems are due, in large part, to other components of the wheel
end assembly, including the bearing/hub assembly, which is
comprised of a wheel hub and a bearing or the knuckle/hub assembly,
which is comprised of a knuckle, a heel hub, and a bearing.
[0006] One factor that contributes to this run-out is the stack-up
of the individual components in a knuckle/hub assembly, i.e., their
combined tolerances. While the tolerances of each part can be
reduced when they are separately machined, when the parts are
assembled, the combined tolerances stack up, causing run-out that
is still relatively significant. Another factor that contributes to
stack-up is any variation in the turning processes that are used to
machine the flange surface, when the wheel hub is individually
machined, in an effort to make it flat with respect to the rotor.
Further, the installation and press condition of the wheel bolts,
the assembly process of the knuckle/hub assembly, and improperly
pre-loaded bearings, can all cause misalignment of the hub surface
with respect to the rotor and thus cause unacceptable run-out. This
run-out can cause premature failure of the brake lining due to
uneven wear which requires premature replacement of the brake
lining at an increased expense. Further, problems due to run-out
include, brake judder, steering wheel "nibble" and pedal pulses
felt by the user, and warped rotors which result in brake noise and
uneven stopping.
[0007] Presently available manufacturing methods and designs of
knuckle hub assemblies limit the accuracy to which lateral run-out
of braking surfaces can be controlled. These methods and designs
are also insufficient to solve the problems associated with
run-out, as discussed above. Current methods typically involve
finishing the knuckle and the hub individually and then assembling
the machined parts to form a completed knuckle/hub assembly. These
methods, however, do not solve the run-out problems due to the
factors discussed above, including stack-up tolerances, turning
process variations, and wheel bolt and bearing installations.
[0008] Other options have been considered in an effort to solve the
run-out problem, but they also all suffer from a variety of
disadvantages. One contemplated option for reducing run-out is to
separately decrease the run-out of each individual component, by
decreasing their respective tolerances during manufacture and then
assembling the components. The "stack up" of tolerance variations
related to such an approach is still significant and provides only
limited system improvement at an increased manufacturing cost.
Another contemplated option includes tightening the press-fit
tolerance variation between the knuckle, the wheel hub, and the
bearing. This, however, significantly increases the difficulty in
the assembly process as well as increases the manufacturing cost.
Further, this option does not provide the desired reduction in
system run-out.
[0009] It would therefore be advantageous to design a knuckle/hub
assembly for a motor vehicle that decreases system run-out without
significantly increasing the manufacturing cost of the assembly or
increasing the manufacturing difficulty.
SUMMARY OF THE INVENTION
[0010] It is therefore an object of the present invention to
provide a knuckle/hub assembly and a method for manufacturing same
that provides reduced wheel hub lateral run-out.
[0011] It is a further object of the present invention to provide a
knuckle/hub assembly and method for manufacturing same that results
in a brake configuration which minimizes brake noise and uneven
stopping.
[0012] It is still a further object of the present invention to
provide a knuckle/hub assembly and method for manufacturing same
that results in a brake configuration which minimizes uneven brake
lining wear and thus the need for frequent lining replacements.
[0013] It is a related object of the present invention to provide a
knuckle/hub assembly and a method for manufacturing same that
results in a brake configuration which increases the life of
vehicle brake linings.
[0014] It is yet another object of the present invention to provide
a knuckle/hub assembly and a method for manufacturing same that
results in a brake configuration which provides improved
performance at relatively lower cost.
[0015] It is yet a further object of the present invention to
provide a tool to allow for the machining of a knuckle/hub assembly
to provide decreased lateral run-out on the outboard wheel hub
flange face.
[0016] In accordance with the objects of the present invention a
knuckle/hub assembly for a motor vehicle is provided. The
knuckle/hub assembly includes a knuckle having a plurality of
apertures formed therein for attachment of the knuckle to a
vehicle. The knuckle also includes a bearing retention portion. The
knuckle bearing retention portion is in communication with a
bearing through press-fitting. The bearing in turn is in rotational
communication with a wheel hub. The wheel hub includes a neck
portion that is pressed into the bearing, and a flange. The flange
has a flange face, which includes an outer portion, an inner
portion, and a relief channel that is formed in the flange face
between the outer portion and the inner portion. The relief channel
has a plurality of bolt holes formed therein with each of the
plurality of bolt holes receiving a wheel bolt passed therethrough.
The inner portion and the outer portion are disposed on the same
plane and are parallel to the caliper mounting features, and
wherein the inner and outer portions have minimal run out with
respect to the bearing axis of rotation.
[0017] In accordance with another object of the present invention,
a method for forming a knuckle/hub assembly having reduced run-out
is provided. The method includes providing a knuckle having a
generally circular bore formed therein. The generally circular
knuckle bore has a bearing press-fit therein. A wheel hub having a
neck portion and a flange portion with a flange face is provided.
The flange face is then machined to form a relief channel therein,
which divides the flange surface into an inner portion and an outer
portion. The inner portion and the outer portion of the wheel hub
flange face are each finished. The relief channel has a plurality
of wheel bolts press-fit into bolt holes formed therein. The neck
portion of the wheel hub is then journaled into the bearing such
that the wheel hub can rotate with respect to the knuckle. The
knuckle/hub assembly is then mounted such that the flange face is
then final finished with the inner portion and the outer portion
being co-planar and parallel with respect to the caliper ears.
[0018] In accordance with another object of the present invention,
an assembly for holding a knuckle/hub assembly while it is final
finished is provided. The assembly includes a standard lathe
machine with a fixture for clamping and locating the knuckle/hub
assembly. The fixture applies a clamping force to the wheel hub and
the inner race of the bearing to generate a pre-load on the
bearing. The fixture also holds the knuckle in place so that the
wheel hub may be rotated. Thereafter, the inner and outer surfaces
of the flange face are final finished so that they are flat and
co-planar with respect to each other. These two surfaces have
minimal run-out when measured back to the knuckle/hub assembly's
axis of rotation.
[0019] These and other features and advantages of the present
invention will become apparent from the following description of
the invention when viewed in accordance with the accompanying
drawings and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a perspective view of a knucklehub assembly in
accordance with a preferred embodiment of the present
invention;
[0021] FIG. 2 is an exploded cross-sectional view illustrating the
components of a knuckle/hub assembly and a brake rotor in
accordance with a preferred embodiment of the present
invention;
[0022] FIG. 3 is a cross-sectional view of the knuckle/hub assembly
in accordance with a preferred embodiment of the present
invention;
[0023] FIG. 4 is a rear view of a knuckle/hub assembly in
accordance with a preferred embodiment of the present
invention;
[0024] FIG. 5 is an end view of a wheel hub flange face in
accordance with a preferred embodiment of the present
invention;
[0025] FIG. 6 is a cross-sectional view of the wheel hub of FIG. 5
along the 6-6;
[0026] FIG. 7 is a top view of a manufacturing fixture assembly for
use in the generation of a knuckle/hub assembly in accordance with
a preferred embodiment of the present invention;
[0027] FIG. 8 is a bottom view of a manufacturing fixture assembly
with a knuckle/hub assembly clamped therein in the direction of the
arrow 8 in FIG. 9 in accordance with a preferred embodiment of the
present invention;
[0028] FIG. 9 is a cross-sectional view of the manufacturing
fixture assembly and knuckle/hub assembly clamped therein of FIG. 7
in the direction of the arrows 9-9;
[0029] FIG. 10 is a cross-sectional view of a puller member of the
manufacturing fixture assembly of FIG. 7 in the direction arrows
10-10;
[0030] FIG. 11 is a cross-sectional view of the manufacturing
fixture assembly, with a knuckle/hub assembly positioned therein,
of FIG. 9 in the direction of the arrows 11-11;
[0031] FIG. 12 is a cross-sectional view of the manufacturing
fixture assembly, with a knuckle/hub assembly positional therein,
of FIG. 9 in the direction of the arrows 12-12;
[0032] FIG. 13 is a cross-sectional view of an alternative
embodiment of a wheel hub assembly in accordance with a preferred
embodiment of the present invention; and
[0033] FIG. 14 is a cross-sectional view of another alternative
embodiment of a wheel hub assembly in accordance with a preferred
embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0034] FIGS. 1 through 4 illustrate a preferred knucklehub
assembly, as generally indicated by reference number 10, in
accordance with the present invention. The assembly 10 is comprised
of a variety of components, including a knuckle 12 and a wheel hub
14. The knuckle 12 is preferably constructed of metal and is
generally formed by casting while the wheel hub 14 is preferably
constructed of metal. The knuckle and hub can obviously be formed
of other materials. The knuckle 12 preferably has a generally
circular bore 16 formed therein and a plurality of outwardly
extending appendages 18 that attach to the vehicle through a
plurality of apertures 20 formed in the plurality of legs 18, as is
well known in the art.
[0035] The bore 16 has a recess 22 formed therein bounded by an
upper snap ring groove 24 and a lower snap ring 26 or shoulder for
receiving a bearing 28 press fit therein. A snap ring 29 is
preferably press fit or otherwise secured into the upper snap ring
groove 24 prior to engagement of the bearing 28 with the knuckle
12. It should be understood that while the illustrated assembly has
a bore 16 formed in the knuckle 12, the bearing 28 can be attached
or secured to the knuckle 12 in a variety of configurations. For
example, the bearing 28 can be mounted to an upper surface or other
portion of the knuckle 12. Alternatively, the bearing 28 can be
only partially disposed in the bore 16. Additionally, the bore 18
can be eliminated altogether.
[0036] The bearing 28 preferably has an outer race 31 and an inner
race 33. However, it should be understood that a variety of
different beatings may be utilized as well as a variety of
different knuckle/bearing attachment configurations. For example,
instead of being press-fit with a snap ring, i.e., between the
upper retention ring 24 and the lower retention ring 26, the
bearing 28 may be press-fit without a snap ring and held in place
with a nut or other known securing methods. Alternatively, the
outer race 31 may be integrally formed with the knuckle 12 (FIG.
14) or may be configured as an orbital formed outer race rotation
bearing/knuckle assembly. Further, the bearing outer race 31 could
alternatively be bolted to the knuckle 12 such that the inner race
33 rotates with the wheel hub 14. Moreover, the inner race 33 may
be integrally formed with the wheel hub 14 (FIG. 13). Further, a
spindle configuration having a non-driven outer race rotation may
also be utilized.
[0037] In the preferred embodiment, the wheel hub 14 has a neck
portion 30 and a flange portion 32. The neck portion 30 is
preferably pressed into contact with the inner race 33 of the
bearing 28 so that the wheel hub 14 can rotate with respect to the
knuckle 12, as shown in FIG. 3. Alternatively, the neck portion 30
may be integrally formed with the inner race 33 or the outer race
31. It should be understood that other wheel hub/bearing
configurations may also be utilized.
[0038] The flange portion 32 has a flange face 34 and a wheel and
rotor pilot portion 36. The wheel and rotor pilot portions 36
extend generally upwardly from the flange face 34 and has an inner
surface 38, which defines a spline 40. The wheel hub 14 also has a
plurality of bolt holes 42 formed in the flange face 34 through
which a plurality of respective wheel bolts 44 are passed. The
plurality of wheel bolts 44 are attached to the flange face 34 in a
predetermined pattern and on the same pitch circle diameter. The
wheel bolts 44 are oriented with the threaded ends extending
outwardly so as to connect a rotor 46 and associated wheel onto the
hub 14 in a fashion, which is more clearly described below.
Alternatively, the wheel hub 14 may have bolt holes 42 that receive
lug nuts that are attached to a vehicle wheel and are passed
through the bore holes 42 when the wheel is attached to the wheel
hub 14.
[0039] As best shown in FIG. 2, the rotor 46 comprises a cup 48
with a central aperture 50 adapted to receive therethrough a wheel
shaft (not shown) affixed to the wheel and rotor pilot portions 36
and extending outwardly from the flange face 34. The cup 48 is
dimensioned to receive the hub flange portion 32 and includes at
its outer end an annular flange 52 having a plurality of apertures
54 lying in the same pitch circle diameter relative to the wheel
shaft as the wheel bolts 44 and having a similar pattern so as to
accommodate the wheel bolts 44 therethrough.
[0040] A pair of parallel, annular discs 56 spaced from each other
by a plurality of rectangular fillets 58 extend outwardly from the
cup 48 and define braking surfaces for a plurality of brake
calipers (not shown). The completion of the assembly to the wheel
is done by positioning the wheel over the bolts 44 and the
threading nuts (not shown) over the bolts 44 so as to secure the
wheel between the nuts and the rotor 46. This invention addresses,
among other things, the problems, which occur between the mating
surfaces of the hub flange portion 32 and the rotor 46.
[0041] Turning now to FIGS. 5 and 6, which illustrate the preferred
wheel hub 14 and flange portion 32 of the present invention. The
flange face 34 has a relief channel 60 machined therein. It should
be understood that the relief channel 60 may also be forged into
the flange face 34 or may be formed by other known methods. The
relief channel 60 divides the flange face 34 into an outer flange
surface 62 and an inner flange surface 64. The relief channel 60 is
turned into the flange face 34 so that the plurality of bolt holes
42 lie in the relief channel 60. The plurality of bolt holes 42 may
be formed either before or after the relief channel 60 has been
formed. The relief channel is preferably set below the level of the
flange face 34, this is to eliminate any surface unevenness caused
by press-fitting the wheel bolts 44 into the bolt holes 42. Any
unevenness due to press-fitting of the wheel bolts 44 is
compensated for by the relief channel 60 as any unevenness will not
be raised with respect to the flange 62, 64, and therefore does not
contribute to any run-out. The relief channel 60 also allows for
final finishing or finish turning to be performed on the assembly
10 after the bolts 44 have been seemed to the wheel hub 14.
[0042] The relief channel 60 is preferably formed in the flange
surface 34 prior to the knuckle 12, the bearing 28, and the wheel
hub 14 being assembled. However, it should be understood that the
relief channel 60 can be formed in the flange surface 34 after the
wheel hub 14 is assembled to the bearing 28 and the knuckle 12 and
before the wheel studs 44 are press-fit therein. In accordance with
the preferred method of forming, the wheel hub 14 has the relief
channel 60 formed therein. Thereafter, the outer flange surface 62
and the inner flange surface 64 are finished. After the finishing
process has been completed, the wheel bolts 44 are press fit into
the bolt holes 42. Thereafter, the hub 14 is mounted to the bearing
28 and the knuckle 12 to form the completed knuckle/hub assembly
10.
[0043] The assembly 10 is then placed into a clamping apparatus, as
is discussed in more detail below, where it is finish turned or
final finished to provide a flat outer flange surface 62 and a flat
inner flange surface 64 that will contact the rotor 46 and thus,
minimize any run out. The refinishing will provide an inner flange
surface 64 and an outer flange surface 62 that are co-planar with
respect to each other so as to provide a flat flange surface 34.
The re-finishing process minimizes run-out with respect to not only
the rotor, but also to the center of rotation of the assembly 68,
as established by the bearing 28. Further, the method and
configuration of the present invention allows the distance between
the caliper ears and the flange surfaces 62, 64 to be accurately
controlled. Additionally, the parallelism between the caliper ears
and the flange surfaces 62, 64 can also be accurately controlled.
In the preferred embodiment, each flange surface has a flatness of
20 [.mu.m] micrometers (or microns) or better. Additionally, the
run-out is minimized to 14 [.mu.m] micrometers (or microns) or
better and the co-planarness of the inner and outer surfaces 62, 64
is 20 [.mu.m] micrometers or better. However, the flatness
requirements may be varied. A person having ordinary skill in the
art will appreciate that as used herein the terms "or better" mean
less than or having a flatness better than the mentioned amount.
For example, a flatness of 15 microns is a flatness better than 20
microns.
[0044] FIGS. 7 through 12 illustrate a preferred part clamping
fixture 70 in accordance with the present invention. The part
clamping fixture 70 is preferably incorporated into a lathe machine
(not shown) and is used to locate and hold the knuckle/hub assembly
10 for refinishing, in accordance with the process described
above.
[0045] As shown in FIG. 7, the part clamping fixture 70 includes a
generally flat top surface 72 for abutting a portion or surface of
the lathe machine. The generally flat top surface 72 includes an
opening 74 formed therein in which a split collar 76 is generally
positioned for engagement with a drive motor from the lathe. The
split collar 76 is disposed such that it is rotatable with respect
to the opening 74. The split collar 76 has a top surface 78 with a
plurality of drive motor engagement notches 80 that communicate
with the drive motor from the lathe in order to rotate the split
collar 76.
[0046] With reference to FIGS. 7 through 12, the part clamping
fixture 70 is shown in more detail. The fixture 70 includes a
plurality of keys 82 that fit into recesses 84 formed in the
generally flat top surface 72. The keys 82 have fasteners 86 that
pass through both the keys 82 and the generally flat top surface 72
to secure the keys 82 to a spacer plate 88. The spacer plate 88 is
disposed on top of a base plate 90 with the two plates 88, 90 being
secured by standard fasteners 92 that extend through the generally
flat top surface 72.
[0047] The split collar 76 has a bore 94 formed therein in which a
toothed gear 96 is disposed. The toothed gear 96 is secured to a
puller member 98 that, when lowered by the lathe, extends generally
downward and into communication with the knuckle 12. The toothed
gear 96 is rotatable with respect to the split collar 76 and is
supported at a bottom surface 100 by a u-joint adapter 102 that has
a central opening 104 formed therein that encompasses the puller
member 98.
[0048] The part clamping fixture 70 has a right housing portion
106, a right cover portion 108, and a right pull piston 110
disposed in the right housing portion 106. The part clamping
fixture 70 also includes a left housing portion 114, a left cover
116, and a left pull piston 118 disposed within the left housing
portion 114. Both the right pull piston 110 and the left pull
piston 118 are secured to the base plate 90 by respective fasteners
112, 120. Each of the right housing portion 106 and the left
housing portion 114 are moveable with respect to the respective
pull pistons 110, 118 such that respective chambers 122, 124 are
formed between each housing portion 106, 114. Each chamber 122, 124
has an orifice 126, 128 in fluid communication therewith allowing
fluid to enter and exit the respective chamber 122, 124 to assist
in moving the right and left housing portions 106, 114 upwardly and
downwardly. The left and right chambers 122, 124 are sealed from
their respective housings 106, 114 by a plurality of o-rings 130.
obviously any other sealing mechanism may alternatively be
utilized. The left pull piston 118 is preferably smaller in length
and diameter than the right pull piston 110 to ensure that equal
forces are applied to the knuckle 12. It should be understood that
the size of the pull pistons 110 and 118 may vary depending upon
the knuckle configuration.
[0049] As shown in FIG. 9, a bayonet 132 is preferably inserted
into the spline 40 defined by the inner surface 38 of the wheel
pilot portion 36 of the flange portion 32. The bayonet 132 is for
engagement with the puller member 98 to lift the knuckle/hub
assembly 10, as described in more detail below. The bayonet 132
preferably engages a washer bore or face 133 in order to lift the
assembly 10.
[0050] As shown in FIG. 11, the right housing portion 106 is
retained in proximity with the base plate 90 by a pair of retaining
blocks 134. Each of the retaining blocks 134 has a supporting
portion 136 that engages a flange portion 138 of the right housing
portion 106. Each of the retaining blocks 134 is secured to the
base plate 90 by a fastener 140 or the like. A pair of guide pins
142 are disposed in the right housing portion 106. Each of the
guide pins 142 is secured to the base plate 90 at an upper end 144
and each is in communication with a spring 146 at a lower end 148.
Each spring 146 fits within a recess 150 formed in the lower end
144 of each of the guide pins 142 and extends downwardly into
contact with the right housing portion 106. The biasing force from
the springs 146 helps bias the right housing portion 106 away from
the guide pins 142.
[0051] As also shown in FIG. 11, the right housing portion 106
includes a pair of bores 152 within which a respective piston 154
reciprocates. Each piston 154 moves between a normally unengaged
position and a knuckle engaging position. The bores 152 are each
sealed adjacent the outer ends 156 of the pistons 154 by an end cap
158. The inner ends 160 of each of the pistons 154 has a gripper
portion 162 and a swiveling gripper portion 164 which allow the
piston 154 to engage and hold the upper strut arm 155 of the
knuckle 12 when the piston 154 is in the knuckle engaging position.
Each piston 154 reciprocates within a bushing 166 secured within
the respective bore 152 to ensure proper alignment of the gripper
portions 162 and the swiveling gripper portions 164 with respect to
the upper strut arm 155.
[0052] Turning now to FIG. 12, which is a cross-sectional view of
the fixture assembly 70 through the left housing portion 114. The
left housing portion 114 is also retained in proximity with the
base plate 90 by a pair of retaining blocks 168. Each of the
retaining blocks 168 has a supporting portion 170 that engages a
flange portion 171 of the left housing portion 114. Each of the
retaining blocks 168 is secured to the base plate 90 by a fastener
172 or other securing means. A pair of guide pins 174 are disposed
in the left housing portion 114. Each of the guide pins 174 is
secured to the base plate 90 at an upper end 176 and each is in
communication with a spring 178 at a lower end 180 of the guide
pins 174. Each spring 178 fits within a recess 182 formed in the
lower end 180 and extends downwardly into contact with the left
housing portion 114. The biasing force from the springs 178 helps
bias the left housing portion 114 away from the guide pins 174. The
left guide pins 174 are preferably smaller in length and diameter
than the right guide pins 142.
[0053] As also shown in FIG. 12, the left housing portion 114
includes a pair of bores 184 within which a respective piston 186
reciprocates. Each piston 186 moves between a normally unengaged
position and a knuckle engaging position. The bores 184 are each
sealed adjacent the outer ends 188 of the pistons 186 by a
respective end cap 190. The inner ends 182 of each of the pistons
186 have a gripper portion 194 and a swiveling gripper portion 196
which allow the pistons 186 to engage and clamp the lower ball
joint 198 of the knuckle 12 when the pistons 186 are in a knuckle
engaging position. Each piston 186 reciprocates within a busing 188
secured within each bore 184 to ensure proper alignment of the
gripper portion 194 and the swiveling gripper portion 196 with
respect to the lower ball joint 198.
[0054] Referring now to FIGS. 9 and 10, which illustrate the puller
member 98 and the surrounding encasing 200. The puller member 98
has a head portion 202 around which the toothed gear 96 is located,
a neck portion 204 which passes through the opening 104 in the
u-joint adapter 102, and a stem portion 206 which is rotatable
within a bore 208 formed in the surrounding encasing 200. The
surrounding encasing 200 has a plurality of bearings 210 disposed
around the bore 208 to assist in the rotation of the stem portion
206.
[0055] The encasing 200 includes an upper body portion 212 that has
an upper end cap portion 214 disposed thereabove, a lower end cap
portion 216 disposed therebelow, and a spacer portion 218 disposed
between the upper body portion 212 and the lower end cap portion
216. The components of the upper body portion 212 are held together
by a fastener 220 or other securing mechanism. The encasing 200
also includes a lower stop portion 222 which is secured to an upper
end cap 224 by a fastener 226 or other securing mechanism. The
upper body portion 212 and the lower stop portion 222 are
surrounded by a body portion 228 having a stop portion 230 secured
thereto. The encasing 200 is preferably secured to the underside of
the base plate 90 by a plurality of fasteners 232, such as bolts or
other securing mechanisms.
[0056] An upper reservoir 234 is preferably formed in the upper
body portion 212. The upper reservoir 234 is in fluid communication
with a fluid inlet port 236 for receiving hydraulic fluid therein.
The upper reservoir 234 is also in fluid communication with a first
fluid orifice 238 formed in the stem portion 206 of the puller
member 98. The first fluid orifice 238 is in fluid communication
with an internal fluid passageway 240 which is in fluid
communication with a second fluid orifice 242 formed in the stem
portion 206. Fluid that passes through the second fluid orifice 242
is passed into a lower reservoir 244. The lower reservoir 244 is
formed between the lower stop portion 222 and the upper end cap
224.
[0057] The stem portion 206 has an annular flange 246 integrally
formed thereon. The annular flange 246 is preferably disposed in
the lower reservoir 244. The annular flange 246 and the upper end
cap 224 are in mechanical communication through the inclusion of a
plurality of springs 248 disposed in recesses 250, 252 formed in
their respective surfaces and a spring drive pin 254. Thus, as
hydraulic fluid enters the lower reservoir 244 through the second
fluid orifice 242, the annular flange 246 is caused to move upward
against the force of the springs 248.
[0058] In operation, a knuckle/hub assembly 10 which is to be
refinished in accordance with the process, as described in detail
above, is located in the lathe and generally beneath the part
clamping fixture 70. The knuckle/hub assembly 10 is preferably
resting on a pallet or other supporting structure with unobstructed
passages. After the knuckle/hub assembly 10 has been located on the
pallet beneath the part clamping fixture 70, the bayonet 132 enters
the spline 40 of the assembly 10 by passing up through the pallet
upon which the assembly 10 is resting. The bayonet 132 is pressed
upward until a shoulder portion 256 contacts the washer face 133 of
the flange portion 32 forcing it upward. The assembly 10 is lifted
by the bayonet 132 at least enough so that the wheel studs 44 are
clear from the pallet 10.
[0059] Thereafter, the lathe lowers the puller member 98 and the
puller encasing 200 through the opening 74 and into communication
with the knuckle 12. The stem portion 206 of the puller member 98
has a recess 258 formed at its lower end 260 which is opposite the
head portion 202. The recess 258 is non-uniform in diameter as in
one orientation, it is large enough to receive a rounded top
portion 260 of the bayonet 132 therewithin. However, when the stem
portion 206 is rotated 90 degrees, its diameter is not large enough
to receive the rounded top portion 260 therewithin or to allow the
rounded top portion 260 to be withdrawn from the recess 258 if it
is positioned therein. Thus, when the puller member 98 is lowered,
it is oriented so as to receive the rounded top portion 260
therewithin.
[0060] After the puller member 98 and the puller encasing 200 have
been lowered, the pair of right pistons 154 and the pair of left
pistons 186 are hydraulically actuated in order to apply a pinching
or clamping force to the knuckle 12. The right pistons 156 apply a
clamping force to the opposing sides of the upper strut arm 155
through the use of the gripper portions 162 and the swiveling
gripper portions 164. Similarly, the left pistons 186 apply a
clamping force to the opposing sides of the lower ball joint 198
through the use of the gripper portions 192 and the swiveling
gripper portions 196. The lifting of the assembly 10 by the bayonet
132 and the lowering of the puller member 98 forces the knuckle 12
into contact with the stop portion 230. The stop portion 230 has an
annular shoulder 262 which engages knuckle 12. These actions locate
the knuckle/hub assembly 10 within the lathe and also fix the
knuckle 12 to the lathe separately from any drive mechanism.
Further, the knuckle 12 acted on by the pullers and grippers so
that the knuckle is fixed and located. The knuckle 12 is not
exposed to any bearing pre-load force.
[0061] After the assembly 10 is located, the bayonet 132 is engaged
by rotating the puller member 98 and the puller encasing 200 with
respect to the surrounding body portion 228. The puller member 98
and the puller encasing 200 are free to rotate with respect to the
body portion 228 and are rotated 90.degree. in order to engage the
bayonet 132. Thereafter, a clamping force is introduced by applying
pressure to the annular flange 236 by introducing hydraulic fluid
into the lower reservoir 244 through the second fluid orifice 242
forcing the puller 20 upward. By pulling the puller member 98 up,
the bayonet 132 is also pulled upward such that the lower stop
portion 222 sits on the inner race 31 of the bearing 28 in order to
apply a force thereto and thus preload the bearing 28.
[0062] After the assembly 10 has been located and clamped as
described above, the final finishing process of the inner and outer
surfaces 62, 64 of the hub flange face 34 can be performed by a
finishing tool. In such a process, the hub 14 is driven such that
it is rotating with respect to the knuckle 12 in which is fixed.
The finishing tool is also preferably single tool such as a CNC
tool, as is well known in the art. However, a variety of the other
finishing tools may alternatively be utilized.
[0063] One of the features of the fixture assembly 70 is to turn
the wheel hub 14 and the bearing 28 compliantly, such that the stem
portion 206 and the annular flange 246 are free to float and follow
the knuckle/hub bearing's axis of rotation. It is further preferred
that the flange surface 34 is probed before final finishing to
ensure a small final finish cut, i.e., decreasing the amount of
material removal that is required during the final finish cut. This
helps control the distance between the caliper ears and the flange
face 34.
[0064] Other objects and features of the present invention will
become apparent when reviewed in light of detailed description of
the preferred embodiment when taken in conjunction with the
attached drawings and appended claims.
* * * * *