Measurement of Helical Gear Transmission Error and Improvement of Analytical Method.

Helical gear transmission error was measured with gear meshing to assess the validity of the conventional numerical analysis of gear meshing. For high-accuracy measurement, high-performance laser rotary encoders, a rigid gear box and rigid gear shafts were used. Three gear pairs with different tooth flank modifications were tested. Alignment errors of test gear pairs were also measured, and considered in the numerical analysis. The numerical analysis assessed is based on Umezawa and Kubo's theory that regards the gear tooth as a plate in deflection analysis. In both the test and the calculation, the amount of transmission error changed according to the working torque, and decreased under some torque conditions. The calculated results corresponded well to the measured results, and numerical analysis proved satisfactory validity for practical use. The slight discrepancy in the results would be reduced by improving the contact and bending deformation of the gear tooth in the numerical analysis.