Fighting Debris: Increasing Life with HTF Bearings for Transmissions

Lubricant contamination is a frequent hazard to bearing life in automotive transmissions. The “Sealed Clean” bearing concept uses dynamic, rubber seals to exclude significant contamination from transmission bearings. However there is often insufficient space in a roller bearing application to accommodate seals. HTF steel specifications and processing were developed for such applications.

Debris within a rotating bearing will create indentations in the raceway. Contact stress is concentrated at the indentation edges and fatigue damage is accelerated. A indentation's diameter and edge radius determine the stress concentration between the ball and raceway. The HTF steel specification and tightly controlled heat treatment processing have been developed to provide long life despite the contamination hazard. Testing confirms the effectiveness of the new material.