PISTON SEAL Russian patent published in 1994 - IPC

FIELD: compressors. SUBSTANCE: sealing members are received by circular grooves in pistons. Chamber formed by members, piston and cylinder is connected with chambers of cylinder by means of passage in piston through normally open check valves. Shutoff members of check valves are made in form of part of end surfaces of two-way spring-loaded spool valve located in additional chamber of piston. Sealing members are made in form of chute-shaped collars with parts of chutes open on side of piston axis forming inter-collar closed chambers together with bottom of piston circular grooves. These chambers are connected with check valves through the throttle valve. Spool valve is made in form of two outer and one inner circular members which are interconnected. Outer circular members are provided with holes. Spool valve is mounted for shutting off the passages which connected chamber between sealing members and inter-collar chamber with piston chamber. EFFECT: enhanced efficiency. 1 dwg