Compressor inlet valve with improved response time

摘要

A compressor has an air inlet valve for controlling air intake when demand for service air from the compressor changes. The valve has a housing with an inlet and an outlet which is connected to a compressor. A rod in the housing is movable relative to the housing and has a shoulder and a piston. A movable valve member is mounted on the rod and a spring is interposed between the piston and the housing for moving the shoulder into engagement with the valve member and biasing the valve member toward the closed position. The housing has a chamber on each side of the piston for receiving air that discharges from the compressor. Air pressure is connected to one of the chambers to move the valve member toward the closed position when the pressure of air in the receiver tank exceeds a set-point. Air pressure is disconnected from the one chamber to reduce bias on the valve member whereby the valve member is permitted to move away from the closed position when the pressure of air in the receiver tank is less than the set-point. The one chamber contains liquid to reduce the volume of air receivable in the chamber and thereby reduce the amount of time required for pressure of air in the chamber to a) increase and move the valve member toward the closed position after pressure of air in the receiver tank exceeds the set-point and b) decrease and reduce bias on the valve member after pressure of air in the receiver tank is less than the set-point.