Stability Characteristics of Spherical Spiral Groove Bearings : 3rd Report. Effects of the Ungrooved Region on Load Capacity and Stability

Abstract

The characteristics of spherical spiral groove bearings, having ungrooved regions at their bottoms, are investigated. The radial bearing forces and the load capacity are found approximately valid for small radial eccentricities, and then the effects of the ungrooved region on the load capacity and the stability are examined. The existence of the ungrooved region alters the characteristics of the bearing. With an increase in the central angle 2θ1 of the ungrooved region, the load capacity diminishes to zero when θ1=90°, while the radial stiffness increases to a maximum value when θ1≒60° and then diminishes to zero when θ1=90°. When a grooved member is rotating and the proper magnitude of the angle θ1 is selected, the bearing has a very high degree of stability without much loss of the load capacity.