Automotive Bearing Materials and Their Application 380165
DEVELOPMENT of higher octane fuels, which will allow more power output through higher compression ratios with a given size engine, and the increasing use of Diesel engines for trucks and buses, will bring about a need for radically superior bearing materials, Mr. Underwood predicts in the early part of this paper.
Stating that a bearing material does not always require excellence in all characteristics, he lists the properties which make a good bearing alloy as: fatigue strength; ability to resist seizure to the steel shaft during periods when there is metal-to-metal contact; good bonding characteristics; mechanical compressive strength; conformability; embeddability; and corrosion resistance.
After describing tests for each characteristic, he treats the functional differences of the present available bearing materials, some of which are still in the final period of development.
Mr. Underwood shows that the numerous commercially available bearing materials have individual characteristics which must be considered in conjunction with the use to which each one is put. Bearings are like people, he says, in that they must be selected for the job they are to perform.
The author believes that future bearing materials will give greater fatigue life than the popular white metals and will have their anti-score characteristics. They will be non-corrosive and less susceptible to dirt and deflections, he adds.
Bearings, he predicts, will be designed for higher load factors as these materials are developed. This trend means narrower bearings, he says, and states that even now one design of connecting-rod has reached the limiting width necessary for the bolt.