VANNE DE COMMANDE POUR LE REGLAGE DU DEBIT D'UNE POMPE

摘要

A manually operable valve for controlling the displacement of a main pump in a hydrostatic transmission controls the quantity of fluid flow to the main pump for low speed operation of the transmission and controls the pressure of the fluid flowing to the main pump during periods of high speed operation of the transmission. The valve includes a pressure chamber acting to substantially balance forces on the valving element to obtain low-effort operation of the control plunger regardless of the position of the element and to automatically close the valve upon a failure in the control linkage for the plunger so that in the event the operator loses control of the valve through linkage failure all power to the transmission is cut off.