Comparison of sinusoidal and involute spur gears by meshing characteristics

Abstract

The article deals with the relevant task of development of gears, that are alternative to the involute (conventional) ones, and can be applied in power drives of machines. The most common requirement for alternative types of gearing is higher comparing with traditional load capacity and durability. To provide this requirement, a sinusoidal gearing can be used. The purpose of this work is to detect its advantages comparing with conventional transmissions. In order to achieve the goal, the theoretical study of qualitative meshing characteristics, which relate to three levels - single, complex and integral, was performed. For gearings the meshing characteristics are the sliding velocity, the velocity of contact points in normal to the contact line direction, relative sliding and reduced curvature. These characteristics belong to the geometric-kinematic group, because they depend on the teeth geometry and the transmission kinematics. They are classified as single and they form part of complex characteristics, which usually include the surface strength of teeth, resistance to scuffing, wear resistance, the oil film’s thickness and the specific work of frictional forces. The complex characteristics, together with geometric-kinematic, determine the gearing power loss. This characteristic is inherently a measure of gearing effectiveness and it is an integral characteristic by its algorithm of definition. It is established that at the extreme points of the line-of-action, the sinusoidal gearing have the characteristic of surface strength at least 10.14 times greater; the characteristic of scuffing at least 10.13 times less; the characteristic of wear of pinion’s teeth surfaces at least 21.58 times less; the characteristic of wear of gear’s teeth surfaces at least 36.81 times less; the characteristic of oil film’s thickness at least 6.57 times more; specific work of frictional forces on the surface of the pinion’s teeth at least 8.3 times less; the specific work of frictional forces on the surface of gear in at least 14.16 times less. The gearing power loss of sinusoidal meshing 2.13 times less. Therefore, the assumption of sinusoidal gearing developer Ernest Wildhaber about the increase of load capacity, as well as the previous results obtained by the first researcher of this gearing Yu.V. Anikin, were approved. The results of the work may be used for further experimental studies, in particular, for the reducers’ load levels selecting during the experiments.