A hollow rolling element for a bearing is fabricated by diffusion welding hollow shells together. The hollow shell halves are joined by faying surfaces and diffusion welding

Moore, T. J.

English

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REPLY TO
ATTN OF:
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
WASHINGTON. D.C. 20546
OCT 1 5 1973
TO: KSI/Scientif ic & Technical Information Division
Attention: Miss Winnie M. Morgan
FROM: GP/Office of Assistant General Counsel for
patent Matters
SUBJECT: Announcement of NASA-Owned U.S. Patents in STAR
In accordance with the procedures agreed upon by Code GP
and Code KSI, the attached NASA-owned U.S. patent is being
forwarded for abstracting and announcement in NASA STAR.
The following information is provided:
U.S. Patent No. i -X ' ^
Government or
Corporate Employee
Supplementary Corporate
Source (if applicable)
NASA patent case No.
tro
. L£\A)- I'l. 636- I'
NOTE - If this patent covers an invention made by a corporate
employee of a NASA Contractor, the following is applicable:
Yes / / No /X /
Pursuant to Section 305(a) of the National Aeronautics and
Space Act, the name of the Administrator of NASA appears on
the first page of the patent; however, the name of the actual
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an invention of ..."
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Enclosure
Copy of patent cited above
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https://ntrs.nasa.gov/search.jsp?R=19730024650 2020-03-17T09:24:07+00:00Z
United States Patent
Moore
[in 3,748,722
[45] July 31, 1973
[54] PRODUCTION OF HOLLOW COMPONENTS
FOR ROLLING ELEMENT BEARINGS BY
DIFFUSION WELDING
[75] Inventor: Thomas J. Moore, Berea, Ohio
[73] Assignee: The United States of America as
represented by the Administrator of
the National Aeronautics and Space
Administration, Washington, D.C.
[22] Filed: Nov. 9, 1971
[21] Appl. No.: 196,970
[52] U.S. Cl 29/487, 29/494, 29/497.5,
29/498
[51] Int. Cl ; B23k 31/02
[58] Field of Search 29/498, 493, 494,
29/497.5, 487
[56] References Cited
UNITED STATES PATENTS
1,3.16,384 9/1919 Murray, Jr. et al....'. 29/498 UX
1,939,467 12/1933 Short et al 29/494 X
3,193,920 7/1965 Culbertson et al 29/492
3,374,529 3/1968 Osborn, Jr. et al 29/498 X
3,528,166 9/1970 Portal et al 29/493
3,550,254 12/1970 Greenspan et al 29/493
3.623,204 11/1971 Wogle 29/493 X
3,626.582 12/1971 Melill 29/497.5 X
3,632,319 1/1972 Hoppin et al 29/487
OTHER PUBLICATIONS
Garrett et al., "Broad Applications of Diffusion Bond-
ing," NASA CR-409, March, 1966, pp. 19-25, 32-36,
80-84 and 138-140. Tech. Library.
Primary Examiner—J. Spencer Overholser
Assistant Examiner—Ronald J. Shore
Attorney—N. T. Musial, John R. Manning et al.
[57] ABSTRACT
A hollow rolling element for a bearing is fabricated by
diffusion welding hollow shells together.
3 Claims, 3 Drawing Figures
fTNASA-Case-LEH-11026-1) PRODUCTION OF
HOLLOW COHPONENTS FOB ROLLING ELEMENT
BEARINGS BY DIFFUSION WELDING Patent
(NASA) 5 p CSCL 131
N73-33383
Unclas
00/15 18060
'PATENTED Jill 3 H973 3.748,722
SHEET 1 OF 2
FIG. I
FIG. 2
BY
-16
INVENTOR
THOMAS J. MOORE
ATTORN £YS
PATENTED JUl 311973 3,748.722
SHEET 8 OF 2
ASSEMBLE
PREFORMED
COMPONENTS
APPLY DEAD-WEIGHT
LOADING TO ASSEMBLED
COMPONENTS
HEAT ASSEMBLED COMPONENTS
IN VACUUM FURNACE
REMOVE FROM FURNACE
FIG. 3
BY
INVENTOR
THOMAS J. MOORE
(P
A T T O R N E Y S
3,748,722
1 2
PRODUCTION OF HOLLOW COMPONENTS FOR in shape for balls or hemicylindrical in shape for rollers.
ROLLING ELEMENT BEARINGS BY DIFFUSION The preformed component 12 has a mating or faying
WELDING surface 16 extending about its periphery. The pre-
'sM>i^iki m? TUC IXIWCKTTT^KT formed component 14 has a similar surface 18 extend-ORIGIN OF THE INVENTION
 5 jng about it/periphery The faying surfaces 16 and 18
The invention described herein was made by an em- are lapped to ensure flatness for optimum mating con-
ployee of the United States Government and may be tact.
manufactured and used by or for the Government for Referring to FIGS. 1 and 3 the preformed compo-
governmental purposes without the payment of any nents 12 and 14 are assembled by placing the surface
royalties thereon or therfor. 10 16 in contact with the surface 18. The preformed com-
BACKGROUND OF THE INVENTION ponents are assembled in the aforementioned manner
by placing the two half shells 12 and 14 into a cort-
This invention is concerned with hollow high strength toured assembly jig 20 shown in FIG. 1. The jig 20 is
rolling elements for bearings. The invention is particu-
 of a suitable material, such as high-purity alumina that
larly directed to an improved method of fabricating 15
 does not react with ^ roUing eiement. The jig 20 in-
hollow balls and rollers from preformed components.
 c|udes a base member 22 having a suitable opening for
Hollow rolling elements, such as balls and rollers, are
 receiving a slidable member 24. The base 22 has a con-
used in bearings to reduce weight. Less energy is re-
 toured surface 26 which mates with the half sheli 14.
quired for aceleration and deceleration with hollow
 The s,idable member 24 has a similarly contoured sur-
rollmg elements because of their lower inertia. 20
 face 2g whjch mates wjth the ha]f she,, 12 as shown in
Electron beam welding has been used to fusion weld
 FJQ j
preformed halves of hollow rolling elements. Areas of
 The assembled components and the jig 20 are placed
high stresses resulted from this welding process be- -n a vacuum chamber 30 ^ shown in FIG. ,. The vac.
cause of excess weld metal or undercut at the root of
 uum chamber 30 Js endoged jn a suitab)e jnsulated con.
the weld. When electron beam welded hollow rolling 25
 tainer 32 havi heati oils 34. ^  vacuum chamber
elements are placed m service cracking tends to start
 30 ether wjth ^ ^^ 32 c rise a vacuum
near the root of the weld causing failure of the bearing.
 fuma^. A ,Qw weldjng pfessure h app,ied to the „.
SUMMARY OF THE INVENTION sembled components by a dead weight 36. The vacuum
™ ., , . . .. , , . . , . ,0 chamber 30 is evacuated to about 2X10~s to 4x10~sThese problems have been solved by fabricating hoi- 3  . _. ., . , , , . „,„A
... . . ... . , ° . , torr. The assembled preformed components are heatedlow bearing elements by welding in accordance with . v . ^Y .
 nnnai! A
t. . . . . -,. , ,, , „ . . in vacuum to a temperature between l,90(rF andthe present invention. The hollow shell halves are „ ,cnapjoined by preparing the faying surfaces of the rolling ' , „ _ , „ . . , . • j .
element components and then diffusion welding. No „ A"er'he exponents ™ >nd 14 have been raised to
macrodeformation is involved, and no foreign material 35 this high temperature under the vacuum condition he
is introduced at the joint. low weldln« Prefure 1S maintained on the assembled
components by the dead weight 36. A very low welding
OBJECTS OF THE INVENTION pressure of about 4 psi is all that is required to form a
It is, therefore, an object of the present invention to hollow rollin« elen>ent. This pressure is maintained on
provide an improved welding method for fabricating 40 the heated components 12 and 14 for between % to 4
hollow rolling elements for bearings. hours to diffusion weld the components at the faying
A further object of the invention is to provide an im- surfaces 16 and 18.
proved hollow rolling element for a bearing. The aforementioned process was used to diffusion
These and other objects of the invention will be ap- weld balls each havin8 a diameter of eleven-sixteenths
parent from the specification which follows and from 45 inch md a thickness of one-sixteenth inch. After weld-
the drawing wherein like numerals are used throughout m& **>« components in accordance with the aforemen-
to identify like parts. tioned process the 11/16 inch diameter balls were
found to be spherical in the as-welded condition. No
DESCRIPTION OF THE DRAWING
 excess material or undercut was present at the welded
FIG. 1 is a vertical section view of apparatus for join- joints.
ing rolling elements in accordance with the present in- While the preferred embodiment of the invention has
vention; been disclosed and described it will be apparent that
FIG. 2 is an enlarged sectional view taken along the various modifications may be made without departing
line 2—2 in FIG. 1; and from the spirit of the invention or the scope of the sub-
FIG. 3 is a flow sheet illustrating diagrammatically 55 joined claims. By way of example, it may be desirable
the process for making hollow rolling elements in ac- to heat treat the welded rolling element after welding,
cordance with the invention. The aforementioned 11/16 inch diameter balls were
DESCRIPTION OF THE PREFERRED minutes and oil quenching. The balls were'then heated
EMBODIMENT 60
 {o j 125°F for two hours and air cooled.
Referring now to the drawing there is shown in FIG. What is claimed is:
1 a hollow rolling element 10 that is fabricated in ac- 1. A method of fabricating a hollow rolling element
cordance with the present invention. The rolling ele- for a bearing from preformed half shell members hav-
ment 10 may be either a ball or a roller and is made by ,, ing a thickness of about one-sixteenth inch comprising
joining two preformed components 12 and 14 shown in the steps of
both FIGS. 1 and 2. The components 12 and 14 are in forming a substantially flat surface about the periph-
the form of half shells which are either hemispherical ery of each of said members,
3,748,722
assembling said members into said hollow rolling ele-
ment configuration in a jig with said flat surfaces in
mating contact,
placing said assembled members and said jig in a vac-
uum furnace,
evacuating said furnace to a pressure between about
2XJO-5and4xlO-5 torr ,
applying dead weight pressure of about 4 psi to said
assembled members, and
heating said assembled members in said vacuum fur-
nace to an elevated temperature between 1,900°F
and 2,1 SOT while maintaining said dead weight
pressure for about one-half hour to about 4 hours
to diffusion weld said members at said flat surfaces.
2. A method as claimed in claim 1 wherein the sub-
stantially flat surfaces are formed by lapping.
3. A method as claimed in claim 1 including the step
of heat treating the rolling element after diffusion weld-
ing.
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Production of hollow components for rolling element bearings by diffusion welding

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