An investigation of misalignment effects on the performance of acetal gears

This paper concentrates on the effects of misalignment on meshing behaviour of acetal gears as hardly any misalignment investigations on polymer gears in the existing literature. The experimental results show that the wear of acetal gears is insensitive to radial and axial misalignments but sensitive to yaw and pitch misalignments which degrade the conjugate contact action. Yaw misalignment leads to 'scoop' wear marks near tooth pitch points. Pitch misalignment causes 'superimposed palisade' wear marks and micro cracks near tooth roots. Compared with metal gears, the effects of small pitch angle on acetal gears are insignificant which may be linked closely to polymer's low elastic modulus. Strikingly different wear striations and various debris morphologies are observed by using scanning electronic and optical microscope (SEM, OM) and misalignment effects can be noted.