| 摘要 |
<p>PURPOSE: To commonly use items and optimize distribution of transmission ratios by adding a third planetary gear device and a brake to a forward four- speed type transmission device including two pairs of planetary gear devices and brakes to modulate it to a forward five-speed type. CONSTITUTION: In a forward five-speed transmission device, a clutch K2 and a brake B3 are fastened at the first speed. The clutch K2 and a brake B2 are fastened at a second speed. The clutch K2 and a brake B1 are fastened at the third speed. Clutches K1, K2 are fastened at the fourth speed. The clutch K1 and the brake B1 are fastened at the fifth speed. A clutch K3 and the brake B2 are fastened at back running. Transmission ratios in these transmission stages are obtained as indicated by an equation by the use of tooth number ratiosα1 toα3 of planetary gear device G11 to G13. This transmission device is modulated to a forward four speed type by removing-the planetary gear device G13 and the brake B3 and connecting a communication member 14 to an output shaft E2. Even in the case that it is modulated to the forward four- speed type, deterioration of fuel consumption performance is avoided at high speed running since the first transmission stage and an overdrive transmission stage remain.</p> |
