Numerical simulation of helical gear continuous generating grinding considering grinding-wheel vibration characteristics and its impact on tooth surface morphology

Abstract

Regular microscopic waves on the surface of a gear tooth are often the primary cause of “ghost frequency” noise problems in new energy vehicle gears. These waves are usually caused by vibrations of the grinding-wheel during the grinding process. In this paper, a continuous generating grinding simulation model that considers grinding-wheel vibrations is proposed to predict the tooth surface texture of gears after grinding using numerical simulation. The accuracy of the grinding simulation model was verified through a single-frequency excitation test. The influence of the grinding-wheel vibration direction, vibration frequency, and processing parameters on tooth surface waves are analyzed in this paper. The results show that the Z-direction of the grinding-wheel vibration has the greatest effect on the amplitude of the tooth surface waves. Non-integer-order grinding-wheel vibrations form a wave angle. The waves on the tooth surface change periodically in the direction of the mesh line movement when the wave angle is close to the helix angle of the base circle, which can easily cause “ghost frequency” noise. The non-integer-order vibration of the grinding-wheel shaft is converted to the tooth surface order based on the speed ratio. When the converted tooth surface order is less than the nearest integer order, the wave angle is negative; conversely, when the order is greater than the nearest integer order, the wave angle is positive. As the linear speed of the wheel increases, the wave angle increases, and as the axial feed rate of the wheel increases, the wave angle decreases. These findings provide actionable insights for optimizing gear grinding processes, enabling manufacturers to enhance gear quality by effectively managing and mitigating the impact of machine tool vibrations.