ROTARY-SPIRAL HYDRAULIC MOTOR Russian patent published in 1998 - IPC

FIELD: bore-hole drilling machinery and equipment. SUBSTANCE: hydraulic motor has hollow body which accommodates stator with flexible shell, rotor, and drive shaft which is connected with rotor. Flexible shell is located between stator and rotor. Flexible shell is secured with stator and fastened on rotor with possible rotation of rotor relative to flexible shell. Created between internal surface of stator and external surface of shell are flow-passing spiral passages for delivery of working fluid. Spiral passages are made with pitch which coincides with pitch of spiral surface of stator. Aforesaid embodiment of hydraulic motor allows for substantial increase of its service life. EFFECT: higher efficiency. 2 cl, 2 dwg