Patent ID: 8556608

Claim:
A rotor drive mechanism configured to transfer rotation of a driving shaft to an external screw type rotor of a uniaxial eccentric screw pump via a connecting shaft, the driving shaft being rotated such that a center thereof is located at a fixed position, wherein: the driving shaft includes an inner space which is open toward the rotor, and the connecting shaft is inserted in the inner space; a base end portion of the connecting shaft is connected to the driving shaft, and a tip end portion of the connecting shaft is connected to the rotor; a first seal portion seals between an inner peripheral surface of an opening of the driving shaft, the opening being open toward the rotor, and an outer peripheral surface of a base end portion of the rotor configured to carry out an eccentric rotational movement or between the inner peripheral surface of the opening of the driving shaft and an outer peripheral surface of the connecting shaft; and the first seal portion deforms such that an inner wall portion thereof moves in a radial direction of the first seal portion and is formed such that the rotor carries out the eccentric rotational movement.