SCREW GEROTOR HYDROMACHINE STATOR Russian patent published in 2006 - IPC E21B4/02 F01C1/107 F04C2/107 

FIELD: gerotor mechanisms of screw downhole motors used for oil and gas well drilling, screw pumps adapted for oil production from wells and general-duty screw hydraulic motors and pumps.

SUBSTANCE: stator comprises hollow body, stator sleeve installed in the body and provided with inner multistart screw teeth, as well as coating secured to the sleeve and having inner multistart screw teeth. The coating is made of elastomeric material, for instance of rubber. Stator sleeve includes several steps having inner multistart screw teeth, wherein inner multistart screw teeth of each step are extensions of inner multistart screw teeth of adjacent step. Surfaces of contacting ends are closed in circumferential direction. Hollow body comprises at least two adaptors located at body ends and enclosing some sleeve steps. Edge, for instance end, of each step is fastened to edge, for instance end, of adjacent step or to edges, for instance ends, of the body and the adaptor by means of weld seams.

EFFECT: improved energy characteristics, service life and reliability of hydromachine.

4 cl, 3 dwg