| 摘要 |
A gear shift control apparatus having made the degree of freedom for selecting a gear ratio higher than that of the case using the Ravigneaux type composite planetary gear train can be obtained (abstract) , while achieving a strength advantage (e.g., the gear strength or the gear lifetime) of the gear train, an improvement in the fuel economy, the coaxial positioning of an input portion and an output portion and the size reduction of an automatic transmission altogether. The apparatus achieves six forward speeds and one reverse speed by engaging/releasing three clutches C1, C2 and C3 and two brakes B1 and B2 properly. One G1 of three planetary gearsets G1, G2 and G3 is a speed-reducing or speed-increasing device for reducing/increasing the speed of an input rotation always. One G3 of the remaining two planetary gearsets G2 and G3 is a double sun gear type planetary gearset, a carrier PC3 of which has a center member CM for inputting or outputting a rotation from between two sun gears S3 and S4. <IMAGE> |
