Search Results

Some papers on gear noise indicate that for helical gears,the vibrational excitation becomes a minimum when the gears in mesh rotate at a total tooth-contact ratio,where the variation of tooth-stiffnes may be minimized (1). Based on this finding, we have designed a pair of herlical gears, of which number of teeth in contact (2,3,or4) would be fixed at any instant of time during the gear rotation. Both the face- and total-contact ratios of involute tooth-face have often been considered to be integers, and a little higher value for the gear with inaccurate tooth-face. Meanwhile, it has been confirmed by computation and experiments that the vibrational excitation of carburized production gears,paired with carburized or hard-finished ones,would decrease if their total contact ratios have been set higher. The present study reveals that the exciting force is much dependent on the total contact ratio, and is little affected by chosing a integer contact ratio.