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This paper describes the development of the ceramic cam roller follower manufactured from silicon nitride. The impact strength of the ceramic roller was investigated and proven to have sufficient strength and reliability for use in automotive engine applications. Motor simulation tests were conducted in order to study the best design for the ceramic cam roller. Results from testing show that super finishing of the roller surface is necessary in order to prevent severe wear of the metal shaft and cam. Optimum bearing clearance range was also studied. Performance tests were conducted in order to study the wear properties of the ceramic cam roller. Wear of the tested cam shaft when using the ceramic roller, was less than the conventional steel roller, even though the calculated contact stress was higher. The total amount of wear of the valve train components was significantly reduced when using the ceramic cam roller, when compared to the conventional steel roller.

High speed precision ball bearings, like those used in machine tool spindles, can have serious problems associated with spin or gyroscopic moment of the rolling elements. The use of low density, silicon nitride ceramic rolling elements reduces these problems. This report presents performance test results of bearings with silicon nitride balls, and steel balls, in a high speed turbine application, using oil jet, and oil mist lubrication methods.