US2031982A - Method of making bearings - Google Patents

Description

Feb. 25, 1936. 5 SALZM'AN 2,031,982

METHOD OF MAKING BEARINGS Filed Sept. 28, 1931 INVENTOR.

Georg: jafifdrt ir (12 a,

A TTORNEYJ.

Patented Feb. 25, 1935 UNITED STATES:

PATENT orncs 2,031,982 METHOD OF MAKING'BEARINGS Application September 28, 1931, Serial No. 565,557

reference to the quantity production of a semicylindrical or half-bearinghaving a bearingmetal 0r babbit lining and conforming to certain necessary precision limits. The herein described method and apparatus is particularly applicable to bearings having a steel outer face, since one of the objects of my invention is to provide means for forming semi-cylindrical shapes which is especiallyadapted to act upon the peculiar bending properties of steel.

A further object is to produce a bearing in which the bearing metal has been subjected to a g compressive force or mechanical coldworking which is productive of a refinement of the grain structure of the metal with corresponding resultant increased strength and durability of the bearing. Objects and advantages additional to those above enumerated shall become apparent during the following description.

. To the accomplishment of the foregoing and related ends, the invention, then, consists of the method hereinafter fully described and particularly pointed out in the claims.

The annexed drawing and the following description set forth in detail certain means and one mode of carrying out the invention, such disclosed means and mode illustrating, however,

- but one of various ways in which the principle of the invention may be used. I

In said annexed drawing:-

Fig. 1 is an elevational view of a pair of-die I blocks constructed in conformity to the principles of my invention, showing the bearing blank in initial position; Figs. *2- and 3 illustrate further steps in the completion of the herein described process; Fig. 4 is a transverse sectional view of a half-bearing in position on a shaft showing the flat spots which occur adjacent-the parting line to an exaggerated degree; Fig. 5 is another transverse sectional vview also showing. to an exaggerated degree the'manner in which the steel die stock tends to bend during ordinary die as practice;

Directing attention particularly toFigs. 1, 2

and 3, a fiat piece of stock I is first placed in position upon the blank holders 2 and 3. This piece of bearing stock I is preferably of a bi- 50 metallic composition, having the steel outer face a and the inner bearing metal or babbit portionb.

The upper or female die 4 has a semi-cylindrical face 5 from which extends'a plunger 6. The plunger 6 carries the stop block 1 upon which 65 bears the compression spring 8. It will thus be 6 Claims. (Cl. 29149.5)

The present invention, relating as indicated to the manufacture of bearings, has more particular lows:-The forming core it], which has a die sur- 10.

face corresponding to a segment of the inner surface of the half-bearing, is carried upon the reciprocal shaft II. The shaft is in turn springlcaded by means of the stop washer I2 and compression spring 3. The compressicnspring I3 15 is of a strength sufficient to overcome the arcuate bending resistance of the bearing blank, I. As shown in Fig. 2, the bearing blank I has been completely conformed to the inner surface 5 of the female die, and the compression spring 13 has not yet begun to act. In Fig. 3, however, upon the exertion of increased pressure upon the die block 9 the resistance of the spring I3 is overcome and the ironing pad M and upsetting punch l5 are forced with a sudden impact against the bearing blank. The ironing pad l4 also servesthe function in that it prevents a thickening of the bearing along those portions with which it contacts, and forces the metal toward the central part of the bearing,- with the result that there is accomplished a uniform upsetting action which is productive of uniform wall thickness. The force with which the punch I5 is driven against the parting line edges i6 and ll of the bearing blank I is sufiicient to impart an upsetting action to the 35 metallic structure of the blank. The die or forming core I0, it should be noted, does not'at any time seat upon the ironing pad or upsetting punch I 4 and [5 respectively, but is always un-' der spring pressure permitting the metal of the 40 hearing blank to move comparatively freely when the upsetting punch l5 strikes home. As shown in Fig. 3, there is always some clearance between the forming core I ii and ironing pad ll along the line 25.

' The purpose of this last-described action of the .forming core ID in conjunction with the ironing pad I4 is to permit the force of the upsetting blow to be transmitted throughout the arcuate section of the bearing blank.

For the purposes of further illustration of the theory of my invention I have shown in Fig. 4 a

bearing blank I which has merely been subjected to the coin-pressingact'ion of two semi-cylindrical dies. It will be noted that there occur the 5 Z4 ment in the bearing metal portion.

be further noted that this final mechanical work'- 'ing or refinement of the grain structure is pro- 10 line of the bearing, and of sufiicient magnitude to rearrange the grain structure of the material ofthe-bearing.

In order to still further illustrate the func tional features of my method and apparatus, 15 there has ,been shown in Fig. 5 the manner in which the die stock, especially when of steel constituency, tends to bulge at its center portion. This bulge is indicated to an exaggerated degree at the point'24.. The presence of the spring 20 loaded retractable plunger 6 therefore is for the purpose of eliminating the tendency of the die stock to bend into a radius less than that of the x semi-cylindrical die. I, y Y

, t should also benoted that the presence of the f ing'co're or die I!) maybe dispensed with p when the upsetting pressure is, exerted along the parting line of the bearing die stock. The forming core Ill, after performing its function of con--' forming the flat blank to the semi-cylindrical die 30 surface 5, effects no, further mechanical'deformation upon the die stock and during the upsetting stroke serves merely as a means for properly re? taining the semijcylindrical blank in-place,

- My method and apparatus perform the further 5 function in that thereis imparted a refining or densifying action upon the bearing metal b. 7 When the bi-metallic blank is first arcuated .as shown in Fig.2, there occurs a slight extrusion of the hobbit, due to the fact that the inner s ace 40 of the bearingblank l is subjected to the gr ater deformation, When the upsetting punch strikes 5 home,as shown inFig. 3, there is exerted upon the babbit metal portion b a secondary mechanical deformation which produces a grain "refine- It should duced by stress acting in a tangential direction,

which hasa tendency therefore to improve the '50 properties of the bearing metal in that particular.direction in which the maximum stresses will be exerted upon it when in use.

, It will thus be seen that my invention provides a'method and means f r economically and rapid I 55 1y producing .sem'i-cyli drical bearings which will 1 not'only conform to the requirements of precl; sion practice, but also possess improved qualities of durability. a f v Othenforms may be employed embodying the features of my invention instead of the one here explained, change being made in the form or cons'truction, provided the elements 'stated by any of I H, I I V J V L bearing,- and then applying a compressive force the following claims or the equivalent of such stated elements be employed, whether produced by-my preferred method or by others embodying steps equivalent to those statedin the following claims.

l I therefore particularly point out and distinctly claim as my invention:---

1. In the manufacture Y of semi-cylindrical bearings and the like, the method of conforming the bearing to a radius equal to that of the com- 10 pleted article and then applying a tangentially directed force against the parting line of.,the bearing suflicient to mechanically deform andrearrange the grain structure ofthe bearing material.

2. In the -manufacture of semi-cylindrical bearingsand the like, the method of arcuating the central portion of a flat blank to a radius equal to that of the completed bearing and then applying a compressive force against the end facesof, said blanlg whereby the blank is subjected to mechanical deformation and the grain structureof its material rearranged. 4

3. In the .manufacture of semi-cy ndrical bearings andthe like, the method of arcuating the central portion "of a hat blank to a radius equal to that of the completed bearing, and then applying a compressive force against the parting line of the bearing, whereby the blank is subjected to me hanical deformation and the grain structure of ts material rearranged.

4. In the manufacture of semi-cylindrical "bearings and the like;'the method of arcuating' the central perigicn' of a flat blank to a radius equal to that of the completed bearing, and then applying a compressive force against the parting line of the bearing, while saidcentral portion is held under forming pressure, whereby the' blank is subjected to mechanical deformation and the grain structure of its material rearranged.

5. In the nufacture of semi-cylindrical bearings and. the like, the method of arcuating the central portion of a flat bla k 'to a radius equal to that of the completed bea ng, and then subjecting the end faces to a sudden impact tangentially directed against the parting line of the bearing, whereby the blank is subjected .to mechanical deformation and the grain structure fofits material rearranged. 6.'-I-n the manufacture of semi-cylindrical bearings and the like, the method of retaining the center portion of a fiat blank against'an arcuate male die surface during the operation of arcuate bending of said blank, conforming said blank to a radius equal to that of the completed againstvthe parting line of the bearing, whereby -the blank is subjected to mechanical deformation and thegrain structureof its material rear ranged. 1

v GEORGE S. SALZMAN.

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