An attitude control means (contact section)(6f) is provided between a side surface of the eccentric shaft section (6a) of a rotating shaft (6), the side surface facing the direction of the eccentricity, and an inner wall surface of a slide hole (5aa), the inner wall surface facing the side surface, at a position coinciding with the axial center of an orbiting bearing (2d). The attitude control means (contact section)(6f) controls the attitude of a balance weight-equipped slider (5) so that the slider section (5a) of the balance weight-equipped slider (5) maintains an attitude parallel to the orbiting bearing (2d).