Variable reluctance stepper motor

Claim 2

A variable reluctance stepper motor comprising: a. a first stator having a plurality of poles, with said poles energizable to generate and selectively rotate a magnetic field, including means for energization comprising a first winding encircling each of said poles and first circuit means for providing plural series circuits, each series circuit including therein a distinct group of such first windings, said first stator generating an incrementally rotating magnetic field upon sequential energization of said series circuits; b. a rotor shaft; c. a first rotor having a second number of poles different from the number of poles in said first stator, said first rotor supported by said shaft in radially spaced relation to said first stator for imparting rotation to said shaft in accordance with rotation of said magnetic field, said first stator and said first rotor together defining a predetermined number of rotational positions for said first rotor where minimum magnetic reluctance exists between said first stator and said first rotor; d. a second stator having a third number of poles; e. a second rotor supported by said shaft in radially spaced relation to said second stator, said second rotor having a fourth number of poles different from said third number of poles with the poles of said rotor and said stator defining a further number of rotational positions for said second rotor wherein a minimum magnetic reluctance exists between said second stator and said second rotor, said further rotational position number being equal to or an integral multiple of said predetermined rotational position number; and f. means associated with said second stator and said second rotor for generating a fixed magnetic field for restraining rotation of said rotor shaft from one of said further predetermined number of rotational positions upon de-energization of said first stator.

Claim 3

A variable reluctance stepper motor comprising; a. a first stator having a plurality of poles, with said poles energizable to generate and selectively rotate a magnetic field; b. a rotor shaft; c. a first rotor having a second number of poles different from the number of poles in said first stator, said first rotor supported by said shaft in radially spaced relation to said first stator for imparting rotation to said shaft in accordance with rotation of said magnetic field, said first stator and said first rotor together defining a predetermined number of rotational positions for said first rotor where minimum magnetic reluctance exists between said first stator and said first rotor; d. a second stator having a third number of poles; e. a second rotor supported by said shaft in radially spaced relation to said second stator, said second rotor having a fourth number of poles different from said third number of poles with the poles of said rotor and said stator defining a further number of rotational positions for said second rotor wherein a minimum magnetic reluctance exists between said second stator and said second rotor, said further rotational position number being equal to or an integral multiple of said predetermined rotational position number, a plurality of windings, each winding encircling one of said second stator poles, said second rotor including a plurality of teeth extending radially relative to said rotor shaft, each of said teeth defining one of said second rotor poles, and inducing signals in said winding of respectively different character upon respective clockwise and counterclockwise rotation of said rotor shaft; and f. means associated with said second stator and said second rotor for generating a fixed magnetic field for restraining rotation of said rotor shaft from one of said further predetermined number of rotational positions upon de-energization of said first stator.

Claim 4

A variable reluctance stepper motor comprising; a. a first stator having a plurality of poles, with said poles energizable to generate and selectively rotate a magnetic field; b. a rotor shaft; c. a first rotor having a second number of poles different from the number of poles in said first stator, said first rotor supported by said shaft in radially spaced relation to said first stator for imparting rotation to said shaft in accordance with rotation of said magnetic field, said first stator and said first rotor together defining a predetermined number of rotational positions for said first rotor where minimum magnetic reluctance exists between said first stator and said first rotor; d. a second stator having a third number of poles; e. a second rotor supported by said shaft in radially spaced relation to said second stator, said second rotor having a fourth number of poles different from said third number of poles with the poles of said rotor and said stator defining a further number of rotational positions for said second rotor wherein a minimum magnetic reluctance exists between said second stator and said second rotor, said further rotational position number being equal to or an integral multiple of said predetermined rotational position number, a plurality of windings, each winding encircling one of said second stator poles, said second rotor including a plurality of teeth extending radially relative to said rotor shaft, each of said teeth defining one of said second rotor poles, and inducing signals in said winding of respectively different character upon respective clockwise and counterclockwise rotation of said rotor shaft; and f. means associated with said second stator and said second rotor for generating a fixed magnetic field for restraining rotation of said rotor shaft from one of said further predetermined number of rotational positions upon de-energization of said first stator.

Claim 5

The motor claimed in claim 2 wherein each of said teeth defines edges successively spaced in the direction of rotation thereof and of respectively different configuration.

Claim 6

A variable reluctance stepper motor comprising; a. a first stator having a plurality of poles, with said poles energizable to generate and selectively rotate a magnetic field; b. a rotor shaft defining a hollow interior in part threaded, said motor further including an exteriorly threaded shaft disposed in said rotor shaft interior in engagement with said threaded part thereof and displaced rectilinearly upon rotation of said rotor shaft; c. a first rotor having a second number of poles different from the number of poles in said first stator, said first rotor supported by said shaft in radially spaced relation to said first stator for imparting rotation to said shaft in accordance with rotation of said magnetic field, said first stator and said first rotor together defining a predetermined number of rotational positions for said first rotor where minimum magnetic reluctance exists between said first stator and said first rotor; d. a second stator having a third number of poles; e. a second rotor supported by said shaft in radially spaced relation to said second stator, said second rotor having a fourth number of poles different from said third number of poles with the poles of said rotor and said stator defining a further number of rotational positions for said second rotor wherein a minimum magnetic reluctance exists between said second stator and said second rotor, said further rotational position number being equal to or an integral multiple of said predetermined rotational position number; and f. means associated with said second stator and said second rotor for generating a fixed magnetic field for restraining rotation of said rotor shaft from one of said further predetermined number of rotational positions upon de-energization of said first stator.

Claim 7

A variable reluctance stepper motor comprising; a. a first stator having a plurality of poles, with said poles energizable to generate and selectively rotate a magnetic field; b. a rotor shaft defining a hollow interior in part threaded, said motor further including an exteriorly threaded shaft disposed in said rotor shaft interior in engagement with said threaded part thereof and displaced rectilinearly upon rotation of said rotor shaft; c. a first rotor having a second number of poles different from the number of poles in said first stator, said first rotor supported by said shaft in radially spaced relation to said first stator for imparting rotation to said shaft in accordance with rotation of said magnetic field, said first stator and said first rotor together defining a predetermined number of rotational positions for said first rotor where minimum magnetic reluctance exists between said first stator and said first rotor; d. a second stator having a third number of poles; e. a second rotor supported by said shaft in radially spaced relation to said second stator, said second rotor having a fourth number of poles different from said third number of poles with the poles of said rotor and said stator defining a further number of rotational positions for said second rotor wherein a minimum magnetic reluctance exists between said second stator and said second rotor, said further rotational position number being equal to or an integral multiple of said predetermined rotational position number; and f. means associated with said second stator and said second rotor for generating a fixed magnetic field for restraining rotation of said rotor shaft from one of said further predetermined number of rotational positions upon de-energization of said first stator.

Claim 8

The motor claimed in claim 4 wherein the surface of said exteriorly threaded shaft defines a slot extending axially relative to said rotor shaft, said motor further including key means engageable with said slot for preventing corotation of said exteriorly threaded shaft with said rotor shaft.

Claim 9

A variable reluctance stepper motor comprising; a. a first stator having a plurality of poles, with said poles energizable to generate and selectively rotate a magnetic field; b. a rotor shaft; c. first rotor having a second number of poles different from the number of poles in said first stator, said first rotor supported by said shaft in radially spaced relation to said first stator for imparting rotation to said shaft in accordance with rotation of said magnetic field, said first stator and said first rotor together defining a predetermined number of rotational positions for said first rotor where minimum magnetic reluctance exists between said first stator and said first rotor; d. a second stator having a third number of poles; e. a second rotor supported by said shaft in radially spaced relation to said second stator, said second rotor having a fourth number of poles different from said third number of poles with the poles of said rotor and said stator defining a further number of rotational positions for said second rotor wherein a minimum magnetic reluctance exists between said second stator and said second rotor, said further rotational position number being equal to or an integral multiple of said predetermined rotational position number; f. means associated with said second stator and said second rotor for generating a fixed magnetic field for restraining rotation of said rotor shaft from one of said further predetermined number of rotational positions upon de-energization of said first stator; and g. a plurality of windings, each winding encircling one of said second stator poles, the windings encircling each of said second stator poles all connected in series with each other.

Claim 10

A variable reluctance stepper motor comprising; a. a first stator having a plurality of poles, with said poles energizable to generate and selectively rotate a magnetic field; b. a rotor shaft; c. first rotor having a second number of poles different from the number of poles in said first stator, said first rotor supported by said shaft in radially spaced relation to said first stator for imparting rotation to said shaft in accordance with rotation of said magnetic field, said first stator and said first rotor together defining a predetermined number of rotational positions for said first rotor where minimum magnetic reluctance exists between said first stator and said first rotor; d. a second stator having a third number of poles; e. a second rotor supported by said shaft in radially spaced relation to said second stator, said second rotor having a fourth number of poles different from said third number of poles with the poles of said rotor and said stator defining a further number of rotational positions for said second rotor wherein a minimum magnetic reluctance exists between said second stator and said second rotor, said further rotational position number being equal to or an integral multiple of said predetermined rotational position number; f. means associated with said second stator and said second rotor for generating a fixed magnetic field for restraining rotation of said rotor shaft from one of said further predetermined number of rotational positions upon de-energization of said first stator; and g. a plurality of windings, each winding encircling one of said second stator poles, the windings encircling each of said second stator poles all connected in series with each other.