Патент USA US2403645код для вставки
July 9, 1946. 2,403,645 E. B.-ETCHELLS METHOD of' MAKING BEARINGS Filed June 7, 194s 2 Sheets-sheet 1 22 'A2595 Bu l/ ft / f ' // ' l l ' " ~ Gttornega’ 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.' / ' EUGENEÁ B. ETCHELLS.