Arizona republican., 1918-01-16

ing loosened. Grooves are generally cut in the babbitt to permit of even distribution of oil. These plain bear ings are commonly used as supports for the crankshaft and for the connecting rod lower ends.
 Obviously complete and copious lu- brication is the life of bearing of this kind. If oil is not present. the shaft rotating at high speed against the metal, generates heat because of the friction and the soft metal is quickly melted, the bearing seizes and the car owner is in for trouble.
 Frequently some of these plain bear inSs will become a little worn, that is the shaft gains a little play. and the result is a knock. When a knock de- velops in the connecting rod bearing this may be taken up by means of shims so as to eliminate the play of the shaft and consequently cure the knock. Shims are strips of metal fit ting between the halves of the bearing. which may be filed down. so as to per init the bearing to be made just lit tie smaller. Another type of shim, known as a laminated one, is made in a number of layers and the removal of one or more of the leaves takes up the bearing
 There is another type of plain bear ing, which consists of simple bronze cylinder without the soft metal lining. These are sometimes called bronze bushings and they are generally used at the top of the connecting rod, in the clutch, on the brake pedals etc.
 The second class of bearings, ball bearings, consist of steel balls revolV- ing between two holders or races. For flexibility and ease of operation the ball bearing is far in the lead, and is used wherever these qualities are the principal need. Ball bearings also nave the advantage of consuming very little of the power passing through them.
 Ball bearings are of more than one type. Some of these parts, having races in the form of rings are known as annular bearings. Another type has a holder or race L-shaped with curved sides facing the balls. These are known as cup and cone bearings, and the princinpal advantage of the type is that it is adjustable, while the annular l bearing is not. Ball bearings are also classified according to the way in which they carry their loads as radial | Oi LII dSl, llie lIlleS DtliS 1dlIly Qe- scriptive. In certain cases a bearing may be built to withstand both radia1 and thrust load. One further classi- ficatiOn must be made among bal bearings and this time as to whether l they have one or two rows of balls.
 Obviously ball bearings must be 1 very accurately manufactured to have them function properly. It follow. | then that they must be properly cared | for to keep them performing their oner. ous task as they are intended to do ! When it is realized that the steel ball! 1 in bearing must not vary more thal one ten thOusandth of an inch, tn, point becomes clear. If one of the ball wears even a little, so that a replace ment is necessary. the only safe wa, is to install complete new set of balls or else to have the old bearing re
 ~round by one of the reliable firm
 doing this work.
 It is essential that the bearings b free from dirt, grit or other foreigl
 matter and from rust. Water mus never be allowed to reach them. Need
 less to say they must have copious an
 proper fabrication When a bearing i
 removed for any reason, it must b
 thoroughly cleaned all over before be
 ing returned. When a bearing
 frightened in it's housing, the nuts mus
 be turned down evenly, so as not t
 cramp the bearing In cleaning ba'
 bearings they should he washed wit