To eliminate a screw shaft or a driven shaft exclusive for shift at an intermediate bearing position when a motor-driven screw shaft 3 supported along a traveling path of a conveying truck 1 is constituted of a plurality of screw shaft single bodies 9A, 9B which are concentrically connected by an intermediate bearing 12A.

In the conveying truck 1, a pivotally supported movable body 16 around the axis 20a of rotation orthogonal to the axis of a screw shaft 3 in an oscillating manner is provided at a side opposite to the side of a supporting part 38 of the intermediate bearing 12A when viewed in the axial direction. Driven rollers 17A-17C are pivotally supported by the movable body 16, respectively, in at least three parts in the circumferential direction along a blade 14 of the screw shaft 3 in a circumferential area not including any supporting part 38 of the intermediate bearing 12A when the screw shaft 3 is viewed in the axial direction.