Friction-induced vibration has been studied in a system consisting of an elastically suspended, damped slider which is loaded against a surface moving at a constant velocity. Exact analysis reveals a critical velocity which limits the incidence of vibration. The critical velocity depends on damping, load, stiffness, and friction characteristics which vary with time and velocity. Approximations in the theory yield an amplitude-velocity equation and another critical velocity relationship. Reasonable agreement is found to exist between the exact and approximate theories for critical velocity. Experimental results for several systems illustrate amplitude-velocity relationships and the existence of critical velocities. The correlation between the experimental results and the approximate theory indicates that the analytical method could be used to predict the vibration behavior of actual systems.

The isothermal Reynolds differential equation of gas film lubrication is written in finite-difference form for numerical analysis of the pressure distribution within spiral-groove thrust bearings and compressors. Appropriate jump equations are presented which provide flow continuity at the land-to-groove interfaces. Gas flow, load support, static stiffness, power consumption, and compressor efficiency are computed and theoretical performance curves are presented for this device. Agreement between computed data and experiment is discussed and presented in graphical form.

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