| 摘要 |
A highly manufacturable gas compressor includes a sheath (50) removably attached to a piston (40) by several resilient fingers (59) that snap into place at the bottom of the piston (40). The fingers (59) act to limit relative motion between the piston (40) and sheath (50) as the piston (40) is reciprocated within a cylinder bore (12). During the suction stroke of the compressor, the piston (40) and sheath (50) separate at their tops, creating an opening at the top of the sheath (50) which allows low pressure gas to flow through an opening (53a, 53b) formed in the side of the sheath (50), between the sheath (50) and piston (40), through the opening (54) at the top of the sheath (50), and into a compression chamber (70) formed between the top surfaces of the piston (40) and sheath (50) and the bottom surface of a discharge valve (80). During the compression stroke, the tops of the piston (40) and sheath (50) combine to form a contiguous surface that compresses the low pressure gas in the compression chamber (70) against the bottom surface of the discharge valve (80), forcing the discharge valve (80) open to release pressurized gas into a discharge chamber (32). The valving sheath (50) includes a lip seal (24) to prevent pressurized gas from escaping the compression chamber (70) between the sheath (50) and cylinder bore wall (22). Slugging protection means (21, 90a, 90b) are provided by the discharge valve (80) and the sheath (50). To eliminate noise and increase efficiency, the sheath (50) and discharge valve (80) are formed from a thermoplastic material. |
