Patent ID: 6913103

Claim:
A hydraulically driven traveling vehicle, comprising: a pair of left and right drive axles; a differential mechanism differentially connecting said pair of drive axles to each other; a traveling hydrostatic stepless transmission; a steering hydrostatic stepless transmission, wherein mutually opposite two-flow output rotations of said steering hydrostatic stepless transmission are separately transmitted to said respective drive axles while output rotation of said traveling hydrostatic stepless transmission is transmitted to an input section of said differential mechanism, thereby making said vehicle travel and turn; a speed change operation tool manipulated by a driver so as to set each speed of said vehicle traveling forward and backward, wherein manipulated variable and direction of said speed change operation tool is converted into an electric signal; a steering operation tool manipulated by a driver so as to set each turning radius of said vehicle turning left and right, wherein manipulated variable and direction of said steering operation tool is converted into an electric signal; a pair of electromagnetic solenoids serving as respective output regulating means of said traveling hydrostatic stepless transmission and said steering hydrostatic stepless transmission, wherein an output current value of each of said electromagnetic solenoids is controlled based on both the electric signals resulting from manipulation of said speed change operation tool and said steering operation tool so as to create an output rotary speed of each of said hydrostatic stepless transmissions corresponding to said controlled output current value, a brake for braking both said left and right drive axles disposed in a transmission system to both said drive axles; and a brake operation tool for acting said brake, wherein the output current values of said pair of electromagnetic solenoids are electrically controlled so as to vanish the output current values of said traveling hydrostatic stepless transmission and said steering hydrostatic stepless transmission, without changing positions of the speed change operation tool and the steering operation tool, when said brake operation tool is operated at a stroke so as to reach a prefixed neutral setting position, wherein both of the output of the traveling hydrostatic stepless transmission and the output of the steering hydrostatic stepless transmission are controlled by both of the speed change operation tool and the steering operation tool, whereby the output of the traveling hydrostatic stepless transmission and the output of the steering hydrostatic stepless transmission are correlated with each other.