ELECTRIC MOTOR DRIVE Russian patent published in 1998 - IPC

FIELD: electric motor drives of sucker-rod pumps used to pump oil out of wells with direct linking up of electric mechanisms to casing pipes. SUBSTANCE: proposed electric motor drive presents combined structure of electric motor, screw converter of rotary motion to translational one and energy recuperator. Electric motor has stator 1 and rotor 2 with hollow shaft 3. Screw converter of rotary motion to translational one includes nut 8 linked up to hollow shaft 3 of rotor and lead screw 7 passing inside hollow shaft, protective enclosure made in the form of bellows 11 which bottom 13 is made fast to nonworking overhang 8 of lead screw and neck 12 is made tight and fast to frame of electric motor drive. EFFECT: prolonged service life and improved technical-and-economic indices. 1 dwg