Abstract: A downhole motor includes a bearing unit connected to a moving section incorporating successively arranged working members--a stator and a rotor interacting with each other along profile surfaces. The like pairs of the adjacent working members are rigidly connected to each other by means of solid threaded bushings. A mounting fixture includes two mounting elements each made as two bushings interconnected by a coupling, the bushings having their profile surfaces located on the same longitudinal axis. One of the bushings is rigidly connected to the coupling, while the other bushing is mounted with the possibility of moving with respect to the longitudinal axis. A method of assembling the downhole motor is effected with the use of a pre-adjusted mounting fixture and resides in interconnecting the like working members by thread bushings ensuring the arrangement of the profile surfaces of the working members analogously to the profile surface of the single monolithic rotor and stator.

Abstract: A valve means to be installed in a string of drill pipe above a bottom hole positive displacement motor comprises a hollow housing (1) having an inlet and an outlet for the passage of a drilling fluid therethrough, the wall of the housing having through holes (4) to communicate the interior of the housing with the annular space of the well bore. Secured in the housing (1) substantially above the through holes is a transverse plate or partition (5) provided with a plurality of calibrated openings (6) intended to produce a pressure drop. The housing (1) further accommodates a chamber (7) communicating with the through holes (4) and provided with an open face in the upper portion thereof, the chamber (7) being arranged such that through passages (10) are formed between the chamber (7) and the housing (1). The housing further comprises a sealing couple (12) intended to prevent the through holes (4) from communicating with the interior of the housing (1) in the course of drilling operation.