Piston-cylinder unit for e.g. linear air compressor, has exhaust pipe deriving fluid into exhaust groove at pressure level lower than pressure in compression space if piston is moved to top dead center or proximity to top dead center

摘要

The unit (1) has a movable piston (203) mounted in a cylinder (2), where an end wall (216) of the piston and an end wall (12) of the cylinder surround a compression space (18) in a region of a top dead center (OT) of the piston. The piston is provided with an exhaust groove (233) into which an exhaust pipe (233'') opens, where the exhaust groove is formed in the end wall of the piston. The exhaust pipe derives a fluid into the exhaust groove at a pressure level lower than the pressure in the compression space if the piston is moved to the top dead center or proximity to the top dead center.