| 摘要 |
PURPOSE:To enable the run of a vehicle at such a fixed speed that the revolution speed of an output shaft is kept constant even if the load torque acting to the output shaft fluctuates, by making it possible to optionally change the revolution speed of the output shaft even if that of an input shaft is constant. CONSTITUTION:A speed changing and steering device comprises a variable- capacity hydraulic pump 27, which is driven by an input shaft 1, a fixed-capacity hydraulic pump 26, which is connected to the pump 27 through an oil passage, a first and a second planet gear units 22, 23, and four clutches 8-11 for changing speed ranges for one another. When the revolution speed of the hydraulic pump 26 is increased on the side of forward rotation from the stopped state of a vehicle as the quantity of discharge of the pump 27 is controlled, a driving rotation entered from the sun gear 22a of the first planet gear unit 22 decelerated and then transmitted to an output shaft 25. As a result, clutch members 9a, 9b are engaged with each other so that motive power from the input shaft 1 is transmitted to a carrier 23b. In that state, the quantity of discharge of the hydraulic pump 27 is controlled. |
