New Concepts in Hydraulic Controls for Mobile Equipment 650669
Analyses and tests were made on various kinds of mobile equipment comparing open and closed center systems. The work cycle and maximum horsepower were kept equal in the comparison of these systems. The closed center system surpassed the open center in both cycle time and efficiency of operation.
New concepts of the closed center system evolved from this work. These concepts included: controlled acceleration and deceleration, selective maximum volume control to prevent overspeeding, and a means of lowering the circuit pressure when the valves are in neutral.
Gains with the integration of the hydrostatic transmission and the closed center hydraulic system are also demonstrated.