Abstract: A claw-pole permanent-magnet stepping motor includes a pair of cases containing two or more inductors in symmetrical arrangement with multiple claw poles. The case unit has an oval shape having thin flat side walls or thin stepped side walls and connecting thick arcuate surfaces operating to resist external flux leakage from the motor and eliminating magnetic circuit obstructions. The cases, side walls, and inductors allow the motor to have a width to length ratio from about one to one to about one to two thus allowing a reduction in size and a low profile design while retaining available output torque.

Abstract: A claw-pole permanent-magnet stepping motor includes a pair of cases containing two or more inductors in symmetrical arrangement with multiple claw poles. The case unit has an oval shape having thin flat side walls or thin stepped side walls and connecting thick arcuate surfaces operating to resist external flux leakage from the motor and eliminating magnetic circuit obstructions. The cases, side walls, and inductors allow the motor to have a width to length ratio from about one to one to about one to two thus allowing a reduction in size and a low profile design while retaining available output torque.

Abstract: A motor with a lead screw is provided with a pre-load generating member for canceling backlash in the axial direction, and the lead screw formed with a feed screw groove portion serves as the output shaft of the motor. The pre-load generating mechanism is constituted by a blind hole, a biasing member, and a movable member. The blind hole is formed concentrically in one end of the lead screw. The biasing member is inserted in the blind hole and has a stroke sufficient to generate a biasing force. The movable member is inserted in the blind hole next to the biasing member to receive the biasing force, and is held to be movable in the axial direction in the blind hole. Hence, the motor with a lead screw can be made short in the axial direction. The biasing member is set to have a sufficiently long stroke so that the stability of the pre-load generating member is maintained high, thereby eliminating backlash in the axial direction.