Valve assembly

摘要

A valve assembly includes a valve having a head and a stem. The head is configured to seal against a valve seat. The stem has a distal end. A first piston radially extends from the stem of the valve and is enclosed within a housing. A second piston is fixed to the distal end of the stem and seals against the housing. A first chamber is defined by the first piston, second piston and the housing and receives a compressed gas and maintains a desired gas pressure. A spring device is disposed intermediate the first piston and the housing. During normal operation of the engine, the gas pressure within the first chamber seals the head of the valve against the valve seat with the spring device in a compressed arrangement and wherein during periods of insufficient gas pressure the spring device biases the valve to seal against the valve seat.

主权项

1. A valve assembly configured for use in an engine, the valve assembly comprising:
a valve having a head connected to a stem, the head configured to seal against a valve seat, the stem having a distal end; a first piston radially extending from the stem of the valve and enclosed within a housing, and configured to seal against a cylinder wall of the housing; a second piston fixed to the distal end of the stem and configured to seal against the cylinder wall of the housing; a first chamber defined by the first piston, second piston and the housing, the first chamber configured to receive a compressed gas and maintain a desired gas pressure; and a spring device disposed intermediate the first piston and the housing; wherein during normal operation of the engine, the gas pressure within the first chamber is configured to seal the head of the valve against the valve seat with the spring device in a compressed arrangement and wherein during periods of insufficient gas pressure within the first chamber the spring device is configured to bias the valve to seal against the valve seat.