Abstract
A cylindrical multi-degree-of-freedom stepping motor for linear and rotary motion is presented and the advantages of the motor are discussed. The stepping motor consists of stators for axial and angular movement and a mover. Considering the shape of the mover's teeth with respect to both axial and circumferential alignment, the magnetic reluctance of the air gap is analyzed to evaluate the maximum static thrust. Moreover, the effect of magnetic saturation is roughly estimated. Maximum static thrust for axial motion is determined to be 7.84 N and maximum static torque for angular motion is 4.9 × 10-2 N·m. Compared with commercially available linear and rotary stepping motors, the merits and demerits of the multi-degree-of- freedom motor are discussed from the viewpoint of static force, mass and input. The new cylindrical motor not only achieves high performance, but realizes a simpler, smaller, lighter mechanism since gears or linkages are not needed.
