| 摘要 |
A driving apparatus comprising a roller screw member (46) that includes a main shaft (48), a plurality of roller shafts (50) projecting radially outwardly and upwardly at an angle ( alpha ) from the radial direction of the main shaft (48) and arranged at equally spaced intervals along a helical line (52) around the main shaft (48), and a plurality of rollers (54) rotatably mounted on the roller shafts (50). The rollers (54) include a roller bearing (56) for mounting them on the roller shafts (50), are tapered to the angle ( alpha ), and are oriented onto the roller shafts (50) with the tapering inwardly to the main shaft (48) thereby providing each roller (54) with the bottom (58) of its tapered surface (60) being perpendicularly oriented with the axis of the main shaft (48). The driving apparatus also includes a rail member (62) adjacent and axially oriented with the main shaft (48) of the roller screw member (46). The rail member (62) includes a plurality of equally spaced projections (64) having inclined upper surfaces (66) adapted for radial engagement with the bottom (58) of the tapered surfaces (60) of the rollers (54). The roller screw member (46) is adapted for axial movement and the rail member (62) is fixed against axial movement, the rotation of the main shaft (48) provides the roller screw member (46) to move in the axial direction of the main shaft (48) with the tapered roller bottom surfaces (58) rotatably engaging the projection upper surfaces (66). The angle ( alpha ) of the tapering is determined to provide a sliding free engagement between the roller surfaces (60) and the projection upper surfaces (66) during the movement. |
