摘要 |
A variable mechanical advantage shaft coupling (1), typically used in an electric power assisted steering system, comprising: an input shaft (2); an output shaft (3); and at least one lever (9), each lever comprising: a lever body; a first connection (5) connecting the lever body to a first shaft (2) of the input shaft and the output shaft at a point offset from an axis of rotation of the first shaft so that the lever body can pivot relative to the first shaft; a second connection (11)connecting the lever body to a second (3), different, shaft of the input shaft and the output shaft at a point offset from its axis of rotation so that the lever body can pivot relative to the second shaft; and a fulcrum point about which the lever body can pivot; in which each first connection (5) is able to slide along an axis substantially parallel to the axes of rotation oft he first and second shafts (2, 3) along the respective lever body, each lever connecting the input and output shafts (2, 3) with a mechanical advantage that varies dependent upon the position of each sliding connection along the first shaft. |