SPEED CHANGER WITH HYDRAULIC MOTOR

摘要

PROBLEM TO BE SOLVED: To reduce a cost and prevent curing in running when changing speed in straight running through stabilization of the capacity changeover speed by making identical the capacity changeover speeds of a left and a right hydraulic motor without depending upon internal pressures of the left and right circuits and without providing pipes for connecting the left and right circuits. SOLUTION: Pressure oil in the left hydraulic circuits 25 and 26 is fed to a left flow control valve 35 to control a flow rate constant. Capacity position of the left variable capacity hydraulic motor 9 is changed over to a capacity position at a plurality of stages by the pressure oil controlled to a constant flow rate by the left flow control valve 35. Pressure oil in the right hydraulic circuits 25' and 26' is similarly fed to a right flow control valve 35' to control the flow rate constant. Capacity position of the right variable capacity hydraulic motor 9' is changed over to a capacity position at a plurality of stages by the pressure oil controlled by the right flow control valve 35' to a constant flow rate.