Angular Fine Positioner
Original Publication Date: 1987-Mar-01
Included in the Prior Art Database: 2005-Feb-02
Mounting one or more small linear motors at the periphery of a polygon allows the small linear motor to overcome a high torque. The linear motor allows a large gap to move in the spoke direction (small rotations are permissible without affecting the motor operation) but no free gap in Z-direction. The cross section of the spoke should not allow any deflection. However, at higher torques, if any small deflection of spoke(s) occurs, it can be easily calculated and configured to compensate an extra angular movement by the linear motor. Fig. 1 shows a 6-spoke polygon mechanism simplified as a triangle. The rotational element (the linear motor 1) is attached to a flexure shaft 2 by spokes 3. It allows small torsional motion but is rigid in bending (X-Y direction).