A METHOD FOR SELECTION OF MODIFICATION COEFFICIENT OF INVOLUTE INTERNAL GEAR PAIR IN ZERO-TOOTH-DIFFERENCE MECHANISM

摘要

The work presented in this paper focuses on a method for selecting modification coefficient of involute internal gear in zero-tooth-difference mechanism which is used in thrust-offset gear coupling designed especially for oil-submerged motor driven progressing cavity pumping system. The daily petroleum production of such pump depends on the eccentricity of the internal gear proportionally while the eccentricity is affected by the modification coefficient. Larger radial and tangential modification coefficient can increase the amount of eccentricity but decrease the strength of gear tooth. The coupling relationship is just what to be found here. The domain of initial value is determined at first. Then, according to the tooth profile engaging equation and other constraint conditions, a reasonable set of modification coefficients is approached. The coefficients can be remodified and readjusted with optimum method until the satisfied result is obtained finally.