摘要 |
<p>An automatic transmission for a vehicle, as provided a plurality of sets of planetary gear units in which the ratios of the tooth numbers of the sun gears to the tooth numbers of the ring gears are different from each other. In the two sets of planetary gear units in which the ratios of the tooth numbers of the sun gears to the tooth numbers of the ring gears are different from each other, the ring gears are identical to each other in the tooth number, the normal module, the normal pressure angle, the angle of torsion, the pitch radius, the base radius, the bottom diameter, the top diameter, the tooth height, the dedendum, the addendum, the lead, the coefficient of normal shift and the arcuate tooth thickness, and the pinions of those two sets of planetary gear units are identical to each other in at least the arcuate tooth thickness, the coefficient of normal shift, the dedendum, the addendum, the tooth height, the angle of torsion, the normal pressure angle and the normal module. <IMAGE></p> |