DC stepping permanent magnetism straight line motor drive type oil-submersible extracting pump

The present invention relates to a submersible oil extraction pump driven by a direct-current magnetoelectric linear stepper motor. The oil extraction pump is composed of a cable (1), a motor cylinder (2), a motor mover (3), a diameter-variable sheath (4), a pump cylinder (5), a plunger (6) and a ball valve set (7); wherein, the upper and the lower ends of the cable (1) are respectively connected with coils arranged in a ground control cabinet (8) and the motor cylinder (2); the upper and the lower ends of the motor cylinder (2) are respectively connected with an oil pipe (9) and the diameter-variable sheath (4) by means of threads; the lower end of the diameter-variable sheath (4) is connected with the pump cylinder (5) by means of threads; the motor mover (3), the plunger (6) and the ball valve set (7) are respectively arranged in the motor cylinder (2) and the pump cylinder (5); and the lower end of the motor mover (3) is connected with the upper end of the plunger (6). With a novel structure, the oil extr