US2242441A

US2242441A - Method of making bearings

Info

Publication number: US2242441A
Application number: US224998A
Authority: US
Inventors: Robert J Shoemaker; Charles M House
Original assignee: Nat Lead Co
Current assignee: NL Industries Inc
Priority date: 1938-08-15
Filing date: 1938-08-15
Publication date: 1941-05-20
Anticipated expiration: 1958-05-20
Also published as: US2242440A

Description

y '20, 4 .1. SHOEMAKER ET AL 2,242,441

METHOD OF MAKING BEARINGS Original Filed Aug. 15, 1938 w WWW "M I I "Wm WWW INVENTORS.

BY mfi iw' ATTORNEY. v

Patented May 20,1941

cago, Ill., assignors, by mesne assignments, to National Lead Company, a corporation of New Jersey Original application August 15, 1938, Serial No. 224,997. Divided and this application August 15, 1938, Serial No. 224,998

3 Claims. (Cl. 29-1495) This invention relates in general to bearings,

and more particularly to an improved method of making the same.

In our co-pending application Serial No. 224,997 filed concurrently herewith, and of which this application is a division, we have disclosed means for materially increasing the resistance to wear, anti-friction properties and life of bearing surfaces, which improved results are accomplished, more specifically, by employing relatively hard wire netting of suitable construction and composition as a reinforcement for a relatively soft bearing metal.

A principal object of this invention is the provision of an extremely effective method of applying such a compound bearing of wire netting and soft bearing metal'to a.desired backing member.

Another important object of the invention is the provision of an improved method of firmly securing to a backing member a soft bearing metal lining.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, when taken in connection with the accompanying drawing, discloses a preferred embodiment thereof.

In the drawing:

Figure l is an end elevation of an engine truck box having a face plate mounted thereon illustrating a preliminary step in' the preparation of a used box for the application of a lateral bearing thereto in accordance with the instant invention;

Fig. 2 is a sectional view taken substantially on the line 2-2 of Fig. 1;

Fig. 3 is an end elevation of the box of Fig. 1 with the wire netting applied thereto; 1

Fig. 4 is a sectional view similar to Fig. 2 of the box of Fig. 3 after the bearing metal hasbeen applied thereto; and I Fig. 5 is a detail vertical section of a part of the mold which is used in pouring the bearing metal.

Referring more particularly to the drawing, reference numeral 2| indicates in general an engine truck box of any suitable construction which is used herein as illustrative of one type of backing member to which the instant invention may be applied in forming a novel lateral bearing surface thereon. For the purpose of illustrating the invention, the box 2| shown in the drawing is one that has been in service so that the lateral wearing surface 22 thereof has been worndown to a certain extent. The instant invention constitutes the application of a novel composite bearing or liner, as illustrated in the parent application hereof abov referred to, to this worn lateral surface 22 of the box 2 I.

In order to effect a material saving in the bearing metal to be applied to-this lateral surface 22, where the engine truck box 2| has previously been in service, the surface 22 is first machined to give a true lateral surface, and an auxiliary steel plate 23 of proper thickness to give the correct lateral dimension to the box M is then mounted thereon. The plate 23 is preferably so shaped as to extend above both the inner and outer marginal portions of the end surface 22. With this arrangement, the plate 23 may be welded to the box 2| at 24 and 25 along the entire inner and outer marginal portions thereof,

and the welds 2t and 25 may be given a bevelled outer surface, as illustrated in Fig. 2. The auxiliary bearing 26, which comprises a wire netting 21' of relatively hard metal and a relatively soft bearing metal 28, is then applied to the outer surface of the plate 23 in'the following manner. The wire netting 27, which is similar in shape to the plate 23 (Fig. 3) with the same inner dimensions as the plate and an outer diameter somewhat smaller than that of the plate, is welded at 29 along its marginal edge portions to the face of the plate. It will be understood that the face of the plate must be free from grease and dirt before the wire netting 27 can thus be applied thereto. It is preferred that the arc welding process, using bronze welding wire, be employed in thus securing the netting 21 t0 the plate 23.

After the wirenetting 21 has been thus secured to the outer face of the plate 23, as shown in Fig. 3, the relatively soft bearing metal 28 is cast thereon, as illustrated in Figs. 4 and 5, in the following manner. face of the plate 23 and the wire netting 21 are first sandblasted until clean. These parts are then pickled for approximately ten minutes, or

" until bright and clean, preferably in a solution of approximately commercial muriatic acid and 50% water. This pickling step has been found to be essential in order to obtain the necessary bond between the bearing metal 28 and the outer face of the plate 23. The pickled portions of the plate and netting should be flushed off with clear water immediately after pickling and the resulting moisture may be. blown off with an air hose.

These pickled surfaces are then fluxed in the Where necessary, the

I usual manner and immersed in a solder pot,

preferably containing 70-30 solder for approximately ten minutes. The flux should not be allowed to dry before immersing in the solder, and the temperature of the solder should be maintained between 650 F. and 700 F. during this operation. Since the life of the bearing 26 depends to a great extent on the soundness of-the tinning, every care should be exercised to insure a thoroughly tinned surface. It is not necessary to sweep or brush off the tinned surface, if a good clean job of preparing such surface is done. The bearing metal 29 must be poured as quickly as possible after tinning, and the pouring operation should consume as little time as possible.

It has been found that the most satisfactory results are obtained when a bearing metal is employed which consists of the following'substances in proportions by weight approximately as follows:

Tin, 0.5% to 2.0%, preferably 1.0%; Calcium, 0.3% to 1.0%, preferably 0.5%;

' Mercury, 0.1% to 0.5%. preferably 0.25%;

Aluminum, 0.02% to 0.1%, preferably 0.05%:

Magnesium, 0.05% to 0.1%, preferably 0.075%;

and/or Potassium, 0.02% to 0.06%. preferably 0.04%;

and/or Lithium, 0.02% to 0.06%, preferably 0.04%;

Lead, to make up 100% In the pouring of this hearing metal, the box 2| is positioned with the outer face of the plate 23 in a substantially horizontal plane, as shown in Fig. 5, with a suitable mold 3| approximately 1 inch deep disposed thereon for retaining the molten metal. The pouring should be done in such a manner as to avoid washing the solder from the tinned surface. To accomplish this. the bearing metal 20 is poured rapidly and at a point or points where it will have to run the least distance to cover the entire surface to which it is applied. At the time of pouring, the bearing metal 20 should be between 950 F; and 1100 F.,

'1 preferably closer-to 1100 than 950. In the type a of application illustrated in the drawing, the

bearing metal." should be poured from 'Ve of an inch to 1 inch in thickness and so as to completely enclose the wire netting 27.

Since it is possible to rupture the soldered bond by rough handling before the latter has cooled sufliciently, great care should be taken in handling the box 2| after the above casting operation. This is due to the fact that the bearing metal 20 solidifies at a higher temperature than a employed only as an expedient ..for reducing'the amount of bearing metal II which must be used.

for example, the plate 23 would not have to be used if the'engine truck box 2| were new. However, the use of such an auxiliary plate will find ready application in many instances, and should be considered as part of the. instant invention. It is thought that the invention and many of its attendant advantages will be understood from v the foregoing description and it will be apparent that various changes may be made in the steps and their order of accomplishment of the process described without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the process hereinbeforo described being merely a preferred embodiment. thereof.

We claim:

1. The method of building up a lateral wearing surface of an engine truck box, or the like, comprisingtruing up said lateral wearing surface by machining thesame, securing a metal plate of substantially the same outline as said surface to the same by welding around the periphery thereof, securing relatively hard metal wire netting to the outer surface ofsaid plate by welding the marginal portions of the netting thereto, 'successively'cleaning, fiuxing and tinning said netting and the outer surface of said plate, casting relatively soft bearing metal on the box to amply cover said tinned surfaces, and machining said bearing metal to the required lateral thickness.

2. The method of applying a bearing to a backing member, comprising securing wire net ting to said backing member by welding the marginal portions of the netting thereto, cleaning the wire netting and the associated surface of the backing member by pickling the same with a suitable acid, tinning such surfaces with 70-30 solder applied thereto at a temperature of between 650 F. and 700 F., and immediately pouring a bearing metal thereon at a temperature between 950 'F. and 1100 F. and completely enclosing said wire netting.

3. The method of applying a bearing to a backing member, comprising securing wire netting to said backing member by welding the' 'temperature between 650 F. and 700 F., and

immediately casting a bearing metal at a temperature of between'950 F. and 1100 F. on said backing member to cover said tinned surfaces and completelyenclose said wire netting,

said bearing metal consisting of the following substances in proportions by weight approxi- In the article. illustrated in the instant drawing.

mately as follows: tin 0.5% to 2.0%, calcium 0.3% to 1.0%, mercury 0.1% to 0.5%, aluminum 0.02% to 0.22%, and metal from the group consisting of magnesium, potassium and lithium 0b0o2% to 0.22%, together with lead to make up 1 a ROBERT J. SHOEMAKER.

CHARLES M. HOUSE.