| 摘要 |
Pressure amplifier for mounting above the drill bit at the lower end of a drill pipe for generating an increased fluid pressure in a drilling fluid flow, for example for obtaining an increased drilling effect. A reciprocating piston (6) in a cylinder (1, 2, 3) at one side (low pressure side) is designed with a large piston area (11), a first, opposite piston area (13) and a second, opposite and relatively small piston area (12) which generates an increased pressure. The valve means (4A-B) control drilling fluid flows to and from the piston. Beyond one end (2) of the cylinder (1, 2, 3) there is provided a hydraulic rotation motor (10) adapted to be driven by the pressure difference between the drilling fluid flows in the drill pipe (1A) and the annulus (50). A transmission mechanism (12, 14A, 14B) is adapted to convert the rotation of the hydraulic motor into intermittent resetting movements in said valve means (4A-B) between two operative positions.
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