| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reduce the drive loss of an oil pump by reducing the number of transmission elements. <P>SOLUTION: This automatic transmission comprises a main transmission unit formed by joining the first/second sun gears of first/second planetary gear trains to each other through a first sun gear shaft and joining a first carrier to a second ring gear through a first transmission shaft and an auxiliary transmission unit formed by joining the third/fourth sun gears of third/fourth planetary gear trains to each other through a second sun gear shaft and joining a third carrier to a fourth ring gear through a second transmission shaft. The main transmission unit is joined to the input shaft of the transmission through the first ring gear and the auxiliary transmission unit is joined to the first transmission shaft through the third ring gear. A gear train for switching between forward and backward movements is installed in a drive force transmission route on the downstream side of the auxiliary transmission unit, the second carrier and the fourth carrier are joined to a transmission case through a one-way clutch, and first/second brake mechanisms are installed to brake the first/second sun gear shafts. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
