An Investigation of Loads, Stress Levels, and Friction Torques of Timer-Mechanism Bearings

摘要

The purpose of this investigation is to analyze the effects of axial and transverse acceleration on bearings of various shapes which may be suitable for use in spring driven timer mechanisms. The investigation considers the feasibility of each bearing in terms of loads, stress levels, and friction torques and indicates appropriate design and analysis techniques. Bearings which can withstand axial load are analyzed. Ten different combinations of shape and pressure distribution are considered. Formulas are derived in each case expressing the required bearing size as a function of its pertinent geometric parameters and the dimensionless axial load. Bearings are analyzed under transverse load. Journal bearings are investigated. An approximate method is developed for calculating contact stresses in terms of transverse load, bearing size, and meridian radius of curvature. In addition expressions for friction torque are developed. Typical loading is considered and numerical values are calculated for this loading. The estimation of typical loading and the investigation of the feasibility, for this application, of sharp vee-jewel bearings as used in precision instruments and watches are also discussed.