FLOW AND LOAD CHARACTERISTICS OF MICROBEARINGS WITH SLIP

The fluid mechanics and operating characteristics of bearings that sup port rotating surfaces in micromachines are different from their large r cousins. The present study analyzes microbearings represented as an eccentric cylinder rotating in a stationary housing. The flow Reynolds number is assumed small, the clearance between shaft and housing is n ot small relative to the overall bearing dimensions, and there is slip at the walls due to non-continuum effects. The two-dimensional govern ing equations are written in terms of the streamfunction in bipolar co ordinates and an infinite-series solution is obtained. For high values of the eccentricity and low slip factors the flow may develop a recir culation region. The force and torque on the load-bearing inner cylind er increase with increasing eccentricity and decrease with increasing slip.