Wildhaber—Novikov circular arc gears: geometry and kinematics

Abstract

An exact analysis of the geometry and kinematics of the Wildhaber—Novikov (W. -N.) system of high-conformity gears is described. The techniques of gear analysis developed by Dyson (1969) are used to obtain the shape of the gap between the gear teeth in contact at zero load. Exact expressions for the entrainment and sliding velocities at the point of contact are also obtained. The theory therefore provides the basic geometrical and kinematic data required for the precise analysis of contact stresses and elastohydrodynamic lubrication. The analysis has been applied to a pair of real gears, and contours of the zero-load gap between the teeth are shown for a range of centre distances and corresponding pressure angles. Values of entrainment and sliding velocities are also obtained for these gears. Regions of potential interference between W. —N. gear teeth are demonstrated and the analysis may be used to show how they can be avoided in practice.