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Патент USA US2403645

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July 9, 1946.
2,403,645
E. B.-ETCHELLS
METHOD of' MAKING BEARINGS
Filed June 7, 194s
2 Sheets-sheet 1
22
'A2595
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July 9, 1946-
E. B. E'rcHELLs
I
METHOD 0F MAKING' BEARINGS
Filed June- 7. 1943
2,403,645
2 sheets-sheet 2
Patented July 9, 1946
2,403,645
4UNrrlazo ,STATES PATENT OFFICE
RIETHOD 0F MAKING `BEARIlälG‘vS
lEugene B. Etchells, Detroit, Mich., assignor to
General Motors Corporation, Detroit, Mich., a'
corporation of Delaware
'
Application June 7, 1943, serial No. 489,892 »
s claims. (c1. :e9-149.5)
- 1
2
‘ This invention has to do with the manufacture
in forming constitutes another check on bonding.
of bearings from sheet metal clad with' bearing
revealing any poor bonding or ñaws or cracks in
the metal of the back or lining'so that th'e bear
metal, such as copper or silver. For best results
the copper or silver should be 4oxygen free.
.
I
-ing may be rejected before machining. The work
In the manufacture of bearings particularly for
service at high speeds and heavy, loads such as
are encountered in aircraft engines, it has been
ing of the metal during drawing tends to refine .
the grain structure and somewhat harden it so
that it wil1 be found desirable to anneal the bear
ings between draws. Annealing also substan
to the shape of a bearing and thereafterappl'y
tially softens the bearing metal and renders it
the bearing metal' usually by casting or electro 10 more
suitable for service.
plating. Diiiiculty has been encountered _in se
In the drawings:
.
_
curing a uniformly good bond between the back
Figure 1 is a sectional view of a suitable blank
and the bearing metal especially when heated l of clad metal adapted ‘to be made into bearings
‘ customary to form the backs, usually of steel,
over 1000° F. for desired softness and grain size -
by my process.
so that a considerable percentage of the bearings 15
v
,
Figure 2 is a sectional view of amodified blank.
manufactured by such methods are discarded be
Figure 3 is a, top plan-view with parts broken ‘
cause of poor bonding or other flaws in the back
away showing the arrangement for guiding the
or liner not discovered until> the machining has
blank into the seat in the press, a. blank beingI
been practically completed. As a consequence all
shown in operative position.
the work spent on the rejected bearing is lost.. 20 'Figure 4 is a diagrammatic view with parts
By making bearings from clad sheet metal the
broken away showing the ñrst drawing operation.
percentage of` defective bearings may be substan
Figures 5, 6, 7, 8 and 9 show in section the
tially reduced and the cost of manufacture sub- , _
shapes which the blank assumes at the endl of
stantially lowered. Sheet steel clad with'copper
successive draws.
y
'
or silver strongly bonded thereto, either with or 25 , Figure 10 shows in section the shape the blank
Without an intermediate bonding metal or alloy,
assumes after the ñnal flange forming operation.
is available on the market.
Figure 11 shows in section the blank as it ap
manufacture of the clad metal involve thorough
pears after the Ibottom has been’removed.
vcleaning of the base metal followed by bonding
Figure 12 is a longitudinal section _through the
or welding the bearing metal thereto usually in a 30 ñnished bearing.
non-oxidizing atmosphere to insure a good bond
The blank shown in Figure 1 preferably con
and prevent oxidation or embrittlement of the
sists
of steel indicated at 20 clad with bearing
bearing metal by absorption of oxygen. There
metal such as copper or silver indicated at 22.
after the composite material'is usually rolled to
This clad‘meta1 may be made by any desired
the desired thickness, the rolling being accom 35 process. For example, sheet steel ñrst thorough
,panied by annealing at intervals and followed by
a final anneal. Annealing should be done in a
_non-oxidizing atmosphere for the reasons pointed
ly cleaned, may be ,ïunited with a thin sheet of ’
silver while hot, preferably under a non-oxidizing
atmosphere, and thereafter the composite stock
may be rolled to the desired thickness aspre
out. The method of manufacture constitutes a
primary check on the character of the bond in 40 viously described; This operation may also, if '
that poor bonding is revealed‘in the rolling and
desired, be conducted under a protecting atmos
annealing operations. Rolling also tends to im
, phere.
prove the bond. The material is carefullyin
In some cases it may be desirable to provide an
spected prior- to manufacture intobearings and
intermediate bonding layer of another metal such
if the bonding is poor or otherwise defectivel the 45 as copper or silver solder between the steel and
blank is rejected before any expense is incurred '
in machining it.
,
.
The preferred method of making the cladsheet
metal into bearings consists in drawing it into
silver. 'I'he copper may be applied to the cleaned'
' steel by electroplating or by fusing or bonding a’
thin layer of copper to the steel. the silver there
after being applied to the copper after thorough
cups of the desired size by means of successive 50 cleaning, and united with it by means of heat
draws and at the same time ,forming an end
and pressure.
'
'
ñange thereon _if desired, and thereafter cutting
of! the closed end of the cup and machining the
bearing to finished dimensions. The advantage
of this procedure is that the working of the metal
The> clad metal may, if desired, consist of steel
' with av coating' of copper strongly bonded to it
as, for example, by hydrogen brazing. However,if preferred, thecopper lmay be united tc- the4 '
2,403,545
steel by means of an intermediate metal or alloy.
The copper or silver coating should be oxygen#
free because of the superior frictional and other
properties of the oxygen-free metal. Further
more if the metal is not free of oxygen it becomes
brittle when the bearing is given the preferred
annealing treatment in a non-oxidizing atmos- `
phere as hereinafter described.
Schlachter,> serial No. 342,061, med June 24, 1940.
The alloy may consist of. approximately 95%
lead and 5% tin to protect the lead against cor
rosion. Another alloy suitable for filling the
depressions in the grid consists of approximately
93% lead, 4% tin and 3% antimony. After ap
plication of this alloy, the bearing is heat-treated
at approximately 450° F. in oil or air followed
by a rapidquench. This has the eirect of re
The invention is equally applicable to clad met
taining the antimony in solution thereby increas
al, such as shown in Figure 2, in which the steel 10. ing the hardness of the alloy and giving it greater
is covered on both sides with bearing metal 2l
fatigue life. If desired, the depressions may be
shown as bonded thereto by an intermediate met
only partially filled with soft bearing metal. Or
al 26, the latter, of course, being optional.
the entire surface, both pits and spaces between
_In the top plan view of th‘e drawing die shown
th'e pits, may be plated with lead or with lead-tin
in Figure 3, 28 indicates the die aperture and
alloy or, other lead alloy resistant to corrosion.
' 30 the guides between which the circular blank
In some instances it may be desirable to an
32 is inserted so that it may be slid in placeover
neal the bearing after knurling to relieve work
the aperture 28. As best shown in Figure 4 the
hardening but I have found it unnecessary in
edges of the blank are normally received within
applications of the invention.
'
an undercut 34 provided in the blank holder 3B. 20 recent
In some instances it. will be found satisfac
When the plunger I0 is advanced the blank 32
tory to omit the lead altogether, the pits in suchà
is drawn to' the form indicated.' The die is pref
case acting as lubricant reservoirs.
erably of the bottomless type andan ejector I2
vThel working to whichth'e clad metal is sub
is provided to knock the formed blank out of the
jected in its manufacture and in drawing the
25
die.
blank- to bearing sh'ape constitutes a very good
Figures 5, 6, 7, 8 and 9 show successive stages
check on both the metals involved and the bond
in drawing a blank While Figure 10 shows the
between them. The stretching of the clad metal
sh'ape the blank assumes after the ñnal striking
results in separation of the layers in case the ‘bond
operation in which the blank is given its final
is not strong. Cracks or flaws in the backing
Between draws as well as after the final 30 and covering metal are revealed in like manner.
'This is important in the case of bearings used in
erably in a non-oxidizing atmosphere, to tem
high powered internal combustion engines be
peratures on the orderof 1250°-1300° F. A non
cause disaster may result from their failure and
set.
draw the metal is annealed by heating it, pref
oxidizing atmosphere is necessary to protect the
it is important that every possible precaution be
copper or silver bearing metal. Both silver and ‘ 35 taken to make sure that there are no flaws.
copper are oxidized if heated for a considerable
This process is applicable not only to the manu
time in the air and both absorb oxygen when '
facture of bearings from blanks such as shown
heated to annealing temperatures. In either case
in Figure l in which there is a layer of bearing
the bearing properties of the lining are seriously
impaired. At the annealing temperatures oxygen 40 metal on one surface only of the blank, but also
penetrates the silver to a depth of from .010" to
.015" so that annealing in the air may be prac
tical provided the silver which has been impaired
by oxygen absorption is removed in the subse
quent machining ofthe bearing.
_
It has been found to be important to employ a
greater number of draws than would be necessary
in making the same shape out of plain sheet met
to bearings in which the bearingl material is ap
plied to both surfaces as shown in Figure 2.
1. The methody of making bearings which con
4:5 sists in preparing a steel blank having thermally
. bonded thereto a layer of oxygen-free metal of
` the class consisting of copper and silver, forming
a bearing shape therefrom by successive forming
operations, annealing the shape in 'a non-ox
al. Where too few draws are used there is a
idizing atmosphere between successive forming
60
tendency to produce separation or cracking of
operations and after the final forming operation,
the thin layer of bearing metal.
rough machining the bearing, hardening the
After about the third draw the .edge of the cup ' bearing back by heating the bearing to approxi~
should be trimmed to square it.
.
mately 1600° F. in a protecting atmosphere fol
The operation producing the blank as shown
lowed
by quenching and heating for approximate- in Figure l0 is followed by the 'final annealing 55 ly one hour at ya. temperature on the order of
. referred to for- th'e purpose of softening `the metal
400° F., and thereafter ñnish machining the bear
and relieving working strains. Thereafter the
mg.
.
bottom is removed froml the cup by sawing, turn
2. The method of making bearings which con
ing or the like, and the bearing is machined to
sists in bonding a layer of oxygen free metal of
i‘lnal dimensions. The finished bearing is shown 60 the class consistingvof copper and silver to a flat
in Figure 12. .
,
steel blank, forming a bearing shape therefrom,
In some applications it is desirable to have a
harder back than can lbe obtained by the process
described. Hardening is accomplished by heat
annealing the shape in a non-oxidizing atmos
phere, rough machining the bearing, hardening
the bearing back by heat treatment of the bear
treatment which -is preferably carried out after 65 ing undery a non-oxidizing atmosphere, followed
» the rough machining has been done. In the case
by quenching, tempering the bearing by heat
of a particular composition of steel the heat treat
treatment under a non-oxidizing atmosphere, and
ment consisted in heating the roughly machined
thereafter iinish machining the bearing. `
silver lined bearings at 1600” F. in a protecting
' 3. The method of making bearings which con
atmosphere, followed by quenching in oil or water 70 sists in bonding a. coating of ductile bearing metal
and heating for an hour at 400° F.
_
to a steel blank, forming a bearing shape there
Preferably the bearing surfaces are knurled to
from, annealing the shape, rough machining the
provide small depressions 50 as shown in Figure
bearing, hardening the bearing back by heat
l2 filled with soit metal as described and claimed
treatment of the bearing followed by quenching,
in th‘e copending application of Alfred W.
moans
tempering the bearing. vand thereafter finish ma
chining'the bearing.
.
’
4. The method of making bearings which eon- Y
sists’in 'preparing a steel, blank having securelyA
bonded thereto a layer ot oxygen-free metal of
the class -consisting oi' oxygen-tree copper and
silver. forming a bearing shape therefrom by suc
cessive forming operations.r annealing the. shape
in a non-oxidizing atmosphere between succes
- sive forming operations and after the iinal form
ing operation, rough machining the bearing,
hardening the bearing back by heat treatment
ot the bearing under a non-oxidizingatmosphere
tollow'edby quenching, tempering the bearing by
heat treatment under a vnon-oxidizing atmos
phere, and thereafter finish machining the bear-_`
5.- 'I'he method of making bearings which com
prises bonding a coating of ductile bearing metal
'to s. substantially nat blank of strong base metal,
drawing the blank into the form of a cup. cutting
of! the closed Yend of the cup and thereafter' ma
chining the bearing to finished dimensions.
6. The method oi making bearings which con
sists in bondingv a layer of ductile bearing metal
to a blank of strong base metal, forming a bear
ing shape thereirom by successive drawing opera
tions, annealing the shape between successive
draws, annealing the shape after the drawing,
and machining the shape to the dimensions of a
finished beßring.'
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EUGENEÁ B. ETCHELLS.
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