Problems of Engine Bearing Related To Mechanical Reasons

Problems of Engine Bearing Related To Mechanical Reasons Points : problems of engine bearing related to mechanical reasons, problems in internal combustion engines, ic, engine, auto diesel Incorrect Clearance It is a fallacy to assume that a tight bearing will run in to a nice free fit. Insufficient clearance prevents an adequate flow of oil through the bearings. It must be remembered that the oil must cool as well as lubricate the bearing surfaces. Excessive Clearance An excessive clearance between the bearing and journal or crank pin cause trouble, chiefly as the result of hammering of the bearing in the latter case, which will cause rapid fatigue and breaking up of the bearing surface. Incorrect Tightening Insufficient tightening or over tightening of the retaining screws or nuts will distort the bearing housing and cause rapid failure. Dirt on Linings Particle of dirt or grit embedded in the lining will eventually score the journal or crankpin. The immediate effect of the particle, however, is to displace the lining material, forming a small crater around each particle, which will reduce the clearance between the lining and the journal or crankpin. Dirt Or Grit Behind Bearing Dirt or grit on outer surface of the bearing shell or in the housing will deform the shell and create a high-spot causing a load concentration and local fatigue of the bearing metal.

Incorrect Running- in thin shell bearings do not require running — in the normal sense, the engine should be treated with discretion for the first few hundred miles.

Detonation or spark knocking imposes excessive loads on bearings and thereby shortens their life.

The effect is to impose a sudden and extra load on the piston, the connecting rod, and the bearings. An extra load of this type, added to already loaded bearings, can assist in reducing their life.