Simulation on the vibration characteristics of elliptical gears

Abstract

Elliptical gear drive is a typical non-circular gear drive, which can be used to transmit a variable-ratio rotation and power simultaneously. To date, elliptical gears are commonly used in automatic machinery, pumps, flow meters and printing presses. However, the vibration characteristics of elliptical gears have not been clarified yet. Due to the non-uniform rotation, the vibration of elliptical gear demonstrates particular characteristics, which should be paid attention to in practical application. This article presents a simulation method on the vibration characteristics of elliptical gears. The torsional vibration simulation model of elliptical gears is established and the simulation programme is developed. The particular gear mesh characteristics of elliptical gears are determined and both the inertial effects of the driving and driven sides of elliptical gears are taken into account in the simulation programme. By means of the simulation programme, two elliptical gear pairs which are a single elliptical gear pair and a double elliptical gear pair and, for comparison, two circular gear pairs which are of the same gear properties as the two elliptical gear pairs respectively are investigated. The torque variations, the rotation speed variations and the circumferential vibration accelerations of elliptical gears are analysed. Furthermore, the critical rotation speeds of tooth separation of elliptical gear drives are obtained and their relations with the load torques are also unveiled. Meanwhile the experiments of the test gears are carried out. The agreement of the simulative results and experimental results proves the validity of the simulation method on the vibration characteristics of elliptical gears proposed in this article.