Power transmission system in vehicle

Abstract

In a power transmission system in a vehicle including a continuously variable gear path and a multi-stage gear path, a difference between gear ratios at the start of forward travel and at the start of backward travel is minimized, while using a single-pinion type planetary gear mechanism. The continuously variable gear path includes a forward/backward travel switching mechanism comprising a single-pinion type planetary gear mechanism, and a belt-type continuously variable transmission. A multi-stage gear path comprising gears is set at a gear ratio closer to a LOW side from that of the belt-type continuously variable transmission. A difference between the gear ratios in the multi-stage gear path and the continuously variable gear path can be minimized by using the multi-stage gear path at the start of forward travel of a vehicle and using the continuously variable gear path at the start of backward travel of the vehicle. Thus, when the forward traveling and the backward traveling are switched over from one to another, it is unnecessary to suddenly change the gear ratio of the belt-type continuously variable transmission, which can contribute to an improvement in durability of belt-type continuously variable transmission.

Dependencies are inferred from the claim text.