HST CIRCUIT FOR TRAVELING

摘要

<P>PROBLEM TO BE SOLVED: To provide an HST circuit for traveling which can simplify the pipe arrangement of a motor capacity control circuit for performing hydraulic pressure control on the capacity of a traveling motor based on a forward/backward change-over command. Ž<P>SOLUTION: The HST circuit includes: a main circuit 20 in which the traveling motor is connected in closed circuit connection with a main pump 22 through a pair of main hydraulic pressure pipe lines 30A, 30B; a charge circuit 40 supplying a hydraulic fluid to a low pressure side main hydraulic pressure pipe line 30A or 30B; a flushing circuit 60 returning the low pressure side main hydraulic pressure pipe line 30A or 30B to a hydraulic oil tank 64; and a motor capacity control circuit 70 which allows capacity control of a traveling motor 26 concerned with a commanded traveling direction when forward/backward change-over command, wherein the motor capacity control circuit 70 includes a branch pipe 72 branched from the flushing circuit 60; the circuit introduces a pressure of the low pressure side main hydraulic pressure pipe line 30A or 30B introduced into the flushing circuit 60 as a pilot pressure through the branch pipe 72; and the circuit controls the capacity of the traveling motor 26. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž