schrittmotoru00e4hnliche customs

摘要

A stepping motor type indicator is provided, whose stepping motor forms unambiguous stable points which produce a sufficiently strong holding force in a non-excited condition, making it possible to suppress undesirable movements of a pointer. ÄMeans for ResolutionÜ A stepping motor type indicator comprises a stepping motor 2 which is constructed of a rotor 28 having an output shaft 27 and stators A, B having yokes 23, 26, from which a plurality of 232, 233, 262, 263 extend toward a curved outer surface of the rotor 28, and exciting coils 21, 24 for magnetizing the yokes 23, 26, respectively, wherein the rotor 28 is driven to rotate in accordance with a measurement value, a pointer 4 which is connected to the output shaft 27 of the stepping motor 2 and indicates the measurement value on a dial plate 3, and a stopper pin (rotor arresting means) 7 for stopping the pointer 4 at a specified stopping position P on the dial plate 3. When the exciting coils 21, 24 are not excited, there are formed a plurality of stable points a-1 of the rotor 28 along the turning direction of the pointer 4 due to magnetic forces exerted between the rotor 28 and the yokes 23, 26. The stopping position P of the rotor 28 (pointer 4) determined by the stopper pin 7 is set at a point closer to the stable point a which is located on a decreasing side of dial reading than an approximately middle point M between arbitrarily selected two adjacent stable points (a and b in this example). Since the pole end area of a specific pole tooth 232a chosen from the multiple pole teeth 232, 233, 262, 263 facing the rotor 28 is made different from the pole end areas of the other pole teeth 232, 233, 262, 263 facing the rotor 28 in this construction, the individual stable points a-1 become unambiguous and produce strong holding forces so that an attracting force exerted by the stable point a on the pointer 4 (rotor 28) toward the stopper pin 7 is increased, making it possible to positively suppress undesirable movements of the pointer 4. IMAGE