| 摘要 |
PROBLEM TO BE SOLVED: To maintain image quality by the transfer drum of a copying machine, laser beam printer or the like well by using a stepping motor, whose basic step angle is specific as a motor for driving the transfer drum. SOLUTION: In this directly drive system, which drives a stepping motor by connecting it directly to a transfer drum, a stepping motor whose torque variationΔT is small is selected by increasing the number of phases of a stator winding. In a complex three-phase HB-type stepping motor which involves a double three-phase winding and whose basic stepping angle is 0.3 degree, it is possible to attain rotational variation of 0.2% at a rotational speed N=60RPM. Taking the number Nr of teeth of the rotator R as 100 for the stator S and a deviation angle (α) between two main magnetic pole groups of the stator S asα=30/Nr=0.3 degree, it is possible to provide a stepping motor with basic stepping angleθs=180/(6×100)=0.3 degree. |
