| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a planetary gear train for a vehicle automatic transmission that achieves forward 9-speed and rearward 1-speed gear stages by combining a plurality of planetary gear sets and a plurality of friction members, and reduces friction drag losses by reducing the number of friction members that is not actuated in each shift stage. <P>SOLUTION: The planetary gear train for a vehicle automatic transmission includes: an input shaft to which engine power is transmitted; an output gear for outputting speed-changed rotative power; a first composite planetary gear set; a second composite planetary gear set for receiving the transmitted rotative power of the input shaft and outputting the rotative power after secondarily speed change to forward 9-speed and rearward 1-speed gear stages; eight rotary shafts; and six friction members constituted of three clutches inserted between a rotary shaft selected from the rotary shafts and the input shaft and selectively transmitting the power and three brakes for selectively connecting the rotary shaft selected from the rotary shafts to a transmission housing. <P>COPYRIGHT: (C)2013,JPO&INPIT |
