HYDRAULIC TRANSMISSION OF CONSTRUCTION EQUIPMENT

摘要

PROBLEM TO BE SOLVED: To effectively utilize rating output torque of an engine by accurately detecting absorption torque of a second hydraulic pump with the pure oil pressure constitution and feedback the detected torque on a first hydraulic pump side for precisely conducting all torque control.SOLUTION: A regulator of the hydraulic transmission comprises: a torque feedback circuit 112v that corrects delivery pressure of a main pump 202 so as to simulate the absorption torque of the main pump 202 and outputs the corrected delivery pressure by introducing the delivery pressure of the main pump 202 and load-sensing driving pressure to the circuit; and a torque feedback piston 112f that controls the displacement volume of a main pump 102 such that the displacement volume of the main pump 102 is reduced as the output pressure of the torque feedback circuit 112v increases so as to reduce the maximum torque T12max by introducing the output pressure of the torque feedback circuit 112v to the piston. The torque feedback circuit 112v includes first and second variable pressure reduction valves 112g and 112q.