| 摘要 |
PCT No. PCT/NO95/00179 Sec. 371 Date Apr. 11, 1997 Sec. 102(e) Date Apr. 11, 1997 PCT Filed Oct. 5, 1995 PCT Pub. No. WO96/12083 PCT Pub. Date Apr. 25, 1996A pressure amplifier can be mounted above a drill bit at the lower end of a drill pipe for generating an increased fluid pressure in a drilling fluid flow to, for example, obtain an increased drilling effect, A reciprocating piston in a cylinder has at one side (a low pressure side) a large piston area and also has a first opposite piston area and a second opposite and relatively small piston area, which generates an increased pressure. A valve device controls drilling fluid flows to and from the piston. Beyond one end of the cylinder there is provided a hydraulic rotary motor adapted to be driven by the pressure difference between the drilling fluid flows in the drill pipe and an annulus. A transmission mechanism converts the rotation of the hydraulic motor into intermittent movements of the valve device between two operative positions. |
