| 摘要 |
PCT No. PCT/SU85/00107 Sec. 371 Date Aug. 21, 1987 Sec. 102(e) Date Aug. 21, 1987 PCT Filed Dec. 30, 1985 PCT Pub. No. WO87/04215 PCT Pub. Date Jul. 16, 1987.A downhole screw motor is designed for drilling oil and gas wells. A downhole screw motor has a stator (3) and a hollow rotor (4) having an axial passage (5) in which is mounted a flow regulator (6) having a nozzle (16). The surface of the nozzle (16) washed with working liquid is made up of two chambers disposed in series in the flow direction: an admission chamber (A) and a delivery chamber (B), the surfaces (19, 20) of the chambers being conjugated along a breaking line (21). A portion (22) of the admission chamber (A), which is adjacent to the breaking line (21), is convex with respect to the direction of flow of working liquid, and the cross-sectional area of the admission chamber (A) at the outlet thereof is smaller thereof is smaller than the cross-sectional area of the same chamber at the inlet thereof.
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