Rotor drive mechanism, shaft seal structure for eccentric shaft, and pump device

摘要

To transfer and fill a fluid with high flow rate accuracy and a long operating life, and realize small size, light weight, low cost, and energy saving. A pump apparatus (39) includes: a first rotor drive mechanism (41) configured to transfer rotation of an input shaft portion (50) to an output shaft portion (49) coupled to an external screw type rotor (23) of a uniaxial eccentric screw pump (21), the input shaft portion (50) being rotated with a central axis thereof kept in a certain position; and a uniaxial eccentric screw pump (21), wherein: the output shaft portion(49) is rotatably provided via a bearing at a position eccentrically located with respect to the input shaft portion (50); the rotation of the input shaft portion (50) is transferred through a first power transmission mechanism (41a) including an inner gear (27) to the output shaft portion(49) to cause the output shaft portion(49) to carry out an eccentric rotational movement; and the input shaft portion (50) and the output shaft portion(49) are arranged inside a pitch circle of the inner gear (27).