Application of Tooth Flank Measurement and Numerical Machine Settings

Gear noise problems in hypoid gears are largely dependent on the nature of the tooth flank form, which is usually controlled by tooth-bearing inspection. However it is difficult to obtain consistent evaluation results from such inspection. A skilled operator and a subtle adjust-ment of the cutting machines, because of their complex mechanisms, are also necessary to obtain an acceptable bearing pattern. A new technology using a CMM (Co-ordinate Measuring Machine) has been developed. A set of index numbers to quantify the tooth flank form errors enables the calculation of the corrective machine settings. The desired tooth bearing is obtained after only one correction, which has improved quality consistency of hypoid gears in mass production lines.