US2205876A - Bearing - Google Patents

Description

20 tion that it has a different coeflicientof expanthus produced is employed to produce a bearing 20.

I through which the load is transmitted to it. each. 45

A still further object is to provide a bearing of It is to be noted that not only must the bearing high strength. and journal or other part be similar in structure Patented June 25, 1949 BEARING William J. Conley, Rochester, N. Y., assignor to E. Phelps Langworthy, Rochester, N. Y.

No Drawing. Application September 9, 1937,

Serial No. 163,059

7 Claims. (Cl. 308-242) This invention relates to improvements in stantially less than .8% and a network of cemenbearings. tite if the carbon content is substantially in ex- Standard bearings are, for the most part, process of this amount. The steel described is duced from alloys, the different metals of which spheroidized in any suitable manner. It may,

provide hard and soft constituents. The former for example, be initially heated to a temperature 5 have a relatively low coefficient of friction and of the order of 1500 F. to cause the cementite are adapted to carry the load while the latter to enter into solution with the ferrite and then provide aplastic bed or matrix in which the quenched and reheated to a temperature in the harder constituents are permitted to adjust range of 1l00 F.-1l00 F. to cause the formation 10 themselves to accommodate the journal or other of globular cementite. The steel isheld at this 10 part through which the load is transmitted to latter temperature until a predetermined cementhe bearing. In order to insure, satisfactory pertite count is obtained, the cementite particles formance it is essential that the hard constituents thus produced being uniformly distributed be present in an amount which will enable them throughout the matrix or bed provided by the lit to carry the entire load applied to the bearing ferrite.

without becoming dislodged or wearing exces- I have discovered that, when the heat treatsively, the proportions of the metals beingpredements referred to are so regulated as to producev termined with this object in view. A bearing of a cementite count in a range centering about the character described, however, has the objec- 28x10 spheroids per square inch and the steel sion from the part through which the load is and the journal or other part through which the transmitted to it. Hence when the said part is load is transmitted to the bearing, dry contacta journal, for example, the clearance between ing surfacesare provided which have a coefficient it and the bearing'varies as the working temof friction comparing favorably to that of bronze perature varies, thereby preventing the said on steel, 1. e. between .30 and .40, and hence 25 parts from being fitted in such a manner that a which will prevent excess wearing or' scoring if proper clearance will be maintained at all temfor any reason the parts are not properly lubriperatures. Such a hearing has the further obcated. The cementite particles in the bearing jection that it is of low strength and must, therecarry the load while the ferrite particles provide to fore, in installations in which a high strength for their adjustment. In this respect, therefore, 30 characteristic is required be employed as a lining the constituents of the bearing function in sub for a brass or holder of a. stronger metal. stantially the same manner as those of an alloy The principal object of the present invention bearing. It will be noted, however, that in the is to overcome the above objections, this object present instance the journal or other part 5 contemplating the use of spheroidized steel'for through which the load is transmitted to the both the bearing and the journal or other part bearing has a structure similar to that of the through which the load is transmitted to the bearing, 1. e., hard and soft constituents of cebearing and involving the adjustment of the 'mentite and ferrite, respectively, and that the micro-structures of the co-operating parts to pre- 'said constituents have the same functions as vent excessive abrasion, galling or any other disthose of the bearing. In other words both the 40 turbance of the surfaces which would precede bearing and the part through which the load is wearing orscoring of the contacting surfaces. transmitted to the bearing are structurally simi- A further object is to provide a bearing having lar and provision is made for the automatic. adthe same coeflicient of expansion as the part justment of the load supporting constituents of A still further object is to provide for simand have substantially the same cementite count plicity and economy in the manufacture and asin order to prevent excess wearing or scoring in m sembly of the bearing and cooperating part. the absence of a lubricating medium but the ce- In the practice of the invention a steel having mentite count itself must be within a predetera carbon content in excess of 3% is preferably mined range. The count of 28x10 above noted employed. Such a steel consists of laminated is substantially the value at which optimum rezones of cementite and ferrite surrounded by a results can be obtained. When a steel having a network of ferrite if the carbon content is subcarbon content of .8% was employed the average 55 area of the cementite particles was found to be of the order of .64 As steels of a lower cementite count are employed wearing and scoring of the contacting surfaces increase progressively until at a count of the order of 17 X 10" no practical results can be obtained. In a like manner wearing and scoring of the contacting surfaces increase progressively as the cementite count is raised beyond 223x10 although not so rapidly as when the count is reduced. A steel having a count of 10x10 for example, has proved to be partially satisfactory as will, no doubt, steels having a higher count.

From the foregoing it will be apparent that the use of spheroidized steel in the manner described has the advantage that it enables a bearing to be produced from the same metal as the journal or other part through which the load is transmitted to the bearing. The bearing and journal or other part thus have the same coefficient of expansion and can, therefore, be fitted so that the desired clearance will be maintained under varying operating temperatures. The use of spheroidized steelhas the further advantages that it enables the production of bearings stronger than those of alloys and provides for facility and economy the manufacture and assembly of the parts.

. I claim as my invention:

1. A bearing assembly comprising companion relatively movable parts which are formed to provide cooperating contacting surfaces, said parts being of spheroidized steel and having cementite counts at said surfaces which are substantially equal and which are in excess of 17 x 10 and less than 28x10 spheroids per square inch.

2. A bearing assembly comprising companion relatively movable parts which are formed to provide cooperating contacting surfaces, said parts being of spheroidized steel and having cementite counts at said surfaces which are substantially equal and in excess of 17x10? spheroids per square inch.

3. A bearing assembly comprising companion relatively movable parts which are formed to provide cooperating contacting surfaces, said parts being of spheroidized steel and having cementite counts at said surfaces which are substantially equal and whereby easily machined cooperating steel bearing surfaces are provided being substantially equal in respect to coefficient of expansion, friction, hardness, and resistance to surface disturbance in a range centering about 28x10" spheroids per square inch. 7

4. The method of manufacturing mating steel bearing surfaces comprising spheroidizing the steel to be used so that the mating surfaces comprise spheroidized steel having spheroid carbide counts which are substantially equal and which are of a size ranging from approximately17x10 to 28x10 spheroids per square inch whereby easily machined steel bearing surfaces are provided being substantially equal in respect to coefi'icient of expansion, friction, hardness, and re sistance to surface disturbance.

5. A bearing, the component parts of which comprise metals having a high melting point, said parts being formed of spheroidized steel, the carbide counts thereof ranging above 1'7 10' spheroids per square inch whereby close fitting, high-heat-resisting bearing parts maybe provided moving relatively with the minimum. of mechanical interference between the respective spheroids of said parts with and without lubricant in temperatures up to the range where said carbide particles are disintegrated, or caused to change their form.

6. A hearing metal comprising an easily machinable ferritic mass having heterogeneously arranged therein a plurality of hard globular car-.

bide particles and being of a size and number ranging above, 17x19 globules per square inch whereby a mass of similar hardness in the ab.- sence of lubricant may easily move in bearing relationthereto with a minimum of mechanical and frictional resistance.

'7. A bearing comprising cooperating steel bearing members, each having a steel bearing surface movable and in contact relatively to each other, composed of spheroidized steel, the spheroid counts thereof ranging above 1'7 l0 globules per squareinch whereby easily machined hard surfaced, long-life bearing members are obtained when machined, requiring no further heat treatment.

WILLIAM J. CONLEY.