摘要 |
A power transmission system for swinging the upper section of a mobile crane in opposite directions comprises a prime mover, a torque converter, a modulatable torque converter clutch connected between the prime mover and the torque converter, and a transmission connected to be driven by the torque converter and including a pair of alternately actuatable modulatable transmission clutches therein. The torque converter clutch is modulatable between disengaged and engaged positions. Each transmission clutch is modulatable between a minimum engaged position and a fully engaged position. Selectively operable control means are provided for modulating the torque converter clutch and a selected one of the transmission clutches to swing the crane upper in a desired direction. The control means effect full engagement of the selected transmission clutch prior to full engagement of the torque converter clutch. The control means further include means for sensing torque converter output speed (transmission input speed) and for governing modulation of the torque converter clutch accordingly. |