| 摘要 |
1,156,798. Reciprocating pumps and compressors. P. HAMMELMANN. July 4, 1966 [July 7, 1965], No.29872/66. Headings F1A and F1N. The crank-driven crosshead 5 of a pump or compressor is reciprocated in a housing 8, and is provided with an integral cylinder 5a having a bush 23 which slides over a fixed plunger 7, a central bore 22 in the plunger communicating with coaxial spring-loaded inlet and outlet valves 19, 9. To reduce the dead space, and thus change the output, an insert 20 may be carried by the cylinder 5a so as to reduce the space within the plunger bore. Alternatively the plunger 7 may be changed for one having a smaller bore. To prevent fluid escaping from the cylinder a seal 6 carried by the plunger 7 engages the bush 23. The insert 20 may be provided with a seal 21 which replaces or supplements the seal 6. Any fluid leaking past the seal 6 and/or 21, instead of contaminating the oil in the crankcase, flows to a surrounding annular space 7a connected to atmosphere or to the suction inlet. The plunger 7 is held in the housing 8 against an abutment ring 16 by a screw 17 acting through an intermediate member 12 and a valve seat member 11. |
