| 摘要 |
A down hole wing motor comprises a generally tubular casing (1), a rotor (4) mounted for rotation within the casing (1) with an a nnular chamber (18) therebetween. The casing (1) is provided with angularly spaced apart inlets and outlets (19, 20) for ingress and egress of pressurised working fluid to and from the chamber (8). The rotor (4) has angularly spaced apart wings (15) mounted in radially extending recesses (16) so as to be displaceable therein from a radially projecting position in sealing engagement with the inner casing (1) to a retracted position. The wings (15) and the inlets (19) and outlets (20) are angularly disposed so that a flow of pressurised fluid into the chamber (18) acts against an upstream side (18c) of a first wing 15<1> so as to rotate the rotor (4) while venting fluid from its downstream side (18d) until the wing 15<1> traverses the outlet (20) and a second wing 15<2> traverses the inlet (19) whereupon the process is repeated. The rotor (4) is provided with a conduit (32a) having an inlet for ingress of pressurised working fluid, at a pressure higher thanthat obtaining in the chamber (18) and has outlet portions leading into the radially extending recesses (16) so as to direct a jet flow of pressurised working fluid against the underside of the wings (15) for driving the wings (15) radially outwardly of the recesses (16). The wings (15) and recesses (16) provide clearance passages for the escape of pressurised working fluid jet flow around the wings (15) into the chamber (18) in the radially projecting position of the wings (15). |
