DOWNHOLE MUD MOTOR Russian patent published in 2012 - IPC E21B4/02 

FIELD: engines and pumps.

SUBSTANCE: proposed mud motor comprises oil compensator, stator and rotor devices. Stator device case has cylindrical chambers to accommodate rotor device oval working discs and turn blades in contact with said shaped surfaces to make variable-volume working chambers with intake and discharge openings. Working discs of rotor device are turned in pairs through 90° relative to each other. Said turn blades are fitted to shut off working chamber intake openings. Intake openings are communicated with pressure channels while discharge openings are communicated with drain channels. Said turn blades are free running components. Engine incorporates central shaft running in radial-axial bearings to support rotor device working discs and oil compensator.

EFFECT: simplified design, smaller length.

3 cl, 3 dwg