US 4,255,696 AGranted

Synchronous motor system

AssigneeSigma Instruments, Inc.

InventorJohn H. Field, II

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Abstract

A stepping motor with toothed stator poles and two sets of oppositely magnetized rotor teeth has its stator poles energized by a driver which responds to input pulses to successively deenergize alternate poles and keep them deenergized and then successively reenergize the alternate poles in the opposite direction. Thereafter the driver successively deenergizes the poles intermediate the alternate poles and keeps them deenergized until all intermediate poles are deenergized and then successively reenergizes the intermediate poles in the other direction until all the intermediate poles are reenergized. This drives the rotor in fractional steps. For larger fractional steps, larger numbers of poles are deenergized in response to each pulse. For even larger fractions the deenergization process is eliminated.

Claims14

Dependent claims

A synchronous motor system responsive to input pulses, comprising a motor including a stator and a rotor movable relative to each other about a common axis, said stator having a plurality of radially directed stator poles, said poles having stator teeth arranged in a circle around the axis, said rotor having a plurality of rotor teeth arranged about the axis, said rotor teeth being permanently magnetized, a plurality of winding means on said stator poles for inducing magnetic fields in said poles in radial directions;

and circuit means coupled to said winding means and responsive to input pulses, said circuit means including a plurality of switches each connected in series with one of said winding means, said circuit means including driver means coupled to said switches and responsive to the pulses for rendering a plurality of said switches conductive simultaneously and energizing said winding means simultaneously, said driver means including means for energizing said winding means and inducing magnetic fields in the poles in given directions, deenergizing the winding means on alternate ones of the poles, reenergizing the deenergized ones of the winding means in reverse directions, deenergizing the winding means on the poles intermediate the alternate poles, and reenergizing the winding means on the poles intermediate the alternate poles in a direction reverse to the original direction of energization.

A synchronous motor system responsive to input pulses, comprising a motor including a stator and a rotor movable relative to each other about a common axis, said stator having a plurality of radially directed stator poles, said poles having stator teeth arranged in a circle about the axis, said rotor having a plurality of rotor teeth arranged about the axis, said rotor teeth being permanently magnetized, a plurality of winding means on said stator poles for inducing magnetic fields in said poles in radial directions;

and circuit means coupled to said winding means and responsive to input pulses, said circuit means including a plurality of switches each connected in series with one of said winding means, said circuit means including driver means coupled to said switches and responsive to the pulses for rendering a plurality of said switches conductive simultaneously and energizing said winding means simultaneously, the stator including eight stator poles P1, P2, P3, P4, P5, P6, P7, and P8;
said winding means each including a winding around each of the poles, said circuit means energizing the windings on poles P2, P4, P6, and P8 in the succession North-South-North-South and energizing the windings on the poles P1, P3, P5, and P7 North-South-North-South, said poles P1, P2, P3, P4, P5, P6, P7, and P8 being in peripheral succession on said stator, said circuit means then deenergizing the windings on said poles P1, P3, P5, and P7 in succession and maintaining the deenergization until the windings on the poles P1, P3, P5, and P7 have all been deenergized, said circuit means reenergizing the windings on the poles P1, P3, P5 and P7 in the opposite direction from their prior energization until all the windings on the poles P1, P3, P5 and P7 have been reenergized, during reenergization of the windings on the poles P1, P3, P5, and P7, said circuit means deenergizing the windings on the poles P2, P4, P6, and P8 in succession and maintaining deenergization until all the windings on the poles P2, P4, P6 and P8 have been deenergized and then reenergizing the windings on the poles P2, P4, P6, and P8 in the direction opposite to their original energization and in succession and maintaining the energization until all the windings on the poles P2, P4, P6, and P8 have been reenergized.

Dependencies are inferred from the claim text.

Facts

Application: 05/742,690Filed 17 Nov 1976 · continuation in part
Priority: 2 Feb 1976
Granted: 10 Mar 1981
Term ends: Not estimatedThe source records don’t support an estimate.

Classification2 codes

H02P 8/22
Arrangements for controlling dynamo-electric motors rotating step by step: control of step size; Intermediate stepping, e.g. microstepping
H02P
Control or regulation of electric motors, electric generators or dynamo-electric converters

Family

Serial654,400Parent of this continuation-in-part · filed 2 Feb 1976
US 4,053,966 AParent of this continuation-in-part
US 4,255,696 AThis patent

From the US filing history. Foreign family members aren’t listed.

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