Effects of Eccentricity on Transmission Errors of Trochoidal Gears

This article deals with the effects of eccentricity on transmission errors of trochoidal gears (consisting of a roller gear and cam gear). For the tests, three types of roller gears and three types of cam gears (which had different eccentricity) were used. The experimental results showed that the peak to peak values of transmission errors had a tendency to be greater under a larger eccentricity. The measured transmission error waveforms fluctuated with periods 1/f_r, 1/f_c and 1/z_rf_r (in which f_r and f_c are the rotational frequencies of the roller gears and cam gears, while z_r is the number of rollers). The peaks with nf_r (n = 1, 2, 3, …), nf_c, nz_rf_r, nz_rf_r ± mf_r (m = 1, 2, 3, …) and nz_rf_r ± mf_c appeared in the measured transmission error spectra. The amplitudes of peaks with f_r and nz_rf_r ± mf_r increased as e_r increased, while the amplitudes of peaks with f_c and nz_rf_r ± mf_c increased as e_c increased. The transmission errors of test gears with eccentricity were estimated by the multibody analysis (MBA). A reasonable correlation exits between the calculated results obtained by the MBA and the measured experimental results.