Gear Noise Reduction through Transmission Error Control and Gear Blank Dynamic Tuning

Gear whine can be reduced through a combination of gear parameter selection and manufacturing process design directed at reducing the effective transmission error. The process of gear selection and profile modification design is greatly facilitated through the use of simulation tools to evaluate the details of the tooth contact analysis through the roll angle, including the effect of gear tooth, gear blank and shaft deflections under load. The simulation of transmission error for a range of gear designs under consideration was shown to provide a 3-5 dB range in transmission error. Use of these tools enables the designer to achieve these lower noise limits.

An equally important concern is the dynamic mesh stiffness and transmissibility of force from the mesh to the bearings. Design parameters which affect these issues will determine the sensitivity of a transmission to a given level of transmission error. These dynamics are studied through the use of detailed finite element models of the transmission internals.

A systematic approach to gear element design will be presented to optimize the gear blank design from the perspective of the influence both the transmission error and system dynamics on operating noise. The correlation of model predictions with measured operating data on prototype transmissions will be presented. The model results will be used to illustrate how the use of proper tuning of gear blank resonances can be used to further reduce noise levels by 5 - 10 dB.