Synchronous motor

A synchronous motor which comprises:

• first and second coaxial spaced stator sections, each stator section including at least one annular coil, each stator section being annular and including a plurality of teeth arranged in two circular systems on the inner surface of said stator, the number of teeth in all stator systems being equal and the spacing between adjacent teeth in all stator systems being uniform, said annular coils being each surrounded by a soft ferromagnetic material, said ferromagnetic material and said annular coils constituting a magnetic circuit, said motor further including a rotor having a geometric axis and first, second, third, and fourth circular axially spaced systems of teeth which each comprise a plurality of teeth which are uniformly spaced about the circumference of said rotor, the number of teeth in each of said systems being equal to the number of teeth in every other rotor system and also equal to the number of teeth in each system of teeth in said stator, said systems in said rotor being disposed respectively in first, second, third, and fourth planes which are disposed in substantially normal relationship to said geometric axis of said rotor, each plane in which one of said systems of said rotor is disposed also having one of said systems of said stator disposed therein, each of said systems of said rotor co-operating with one of said systems of said stator, said two systems of teeth in each of said stator sections being shifted angularly by substantially half of a tooth pitch relative to each other and said two stator sections being shifted angularly with respect to each other by substantially a quarter of a tooth pitch, said motor including a single permanent magnet which is disposed axially intermediate said stator sections and which magnetizes two systems of stator teeth which are in the same section and which are also in said first and second planes with substantially identical polarity distributions and two systems of teeth in the same section which are also in said third and fourth planes with substantially identical polarity distributions which are opposite to the polarity distributions of the systems in said first and second planes, said soft ferromagnetic material and said two systems of teeth in each stator section comprising part of a magnetic circuit which surrounds said annular coil of said stator sections, the axial distance between the teeth of said systems in one of said stator sections being at least a few times greater than the spacing between each system of stator teeth and the system of rotor teeth associated therewith, said motor further comprises at least one compensation coil magnetically in parallel with said permanent magnet.

A synchronous motor which comprises:

• first and second coaxial spaced stator sections, each stator section including at least one annular coil, each stator section being annular and including a plurality of teeth arranged in two circular systems on the inner surface of said stator, the number of teeth in all stator systems being equal and the spacing between adjacent teeth in all stator systems being uniform, said annular coils being each surrounded by a soft ferromagnetic material, said ferromagnetic material and said annular coils constituting a magnetic circuit, said motor further including a rotor having a geometric axis and first, second, third, and fourth circular axially spaced systems of teeth which each comprise a plurality of teeth which are uniformly spaced about the circumference of said rotor, the number of teeth in each of said systems being equal to the number of teeth in every other rotor system and also equal to the number of teeth in each system of teeth in said stator, said systems in said rotor being disposed respectively in first, second, third, and fourth planes which are each disposed in substantially normal relationship to said geometric axis of said rotor, each plane in which one of said systems of said rotor is disposed also having one of said systems of said stator disposed therein, each of said systems of said rotor co-operating with one of said systems of said stator, said two systems of teeth in each of said stator sections being shifted angularly by substantially half of a tooth pitch relative to each other and said two stator sections being shifted angularly with respect to each other by substantially a quarter of a tooth pitch, said motor including a single permanent magnet which is disposed axially intermediate said stator sections and which magnetizes two systems of stator teeth which are in the same section and which are also in said first and second planes with substantially identical polarity distributions and two systems of teeth in the same section which are also in said third and fourth planes with substantially identical polarity distributions which are opposite to the polarity distributions of the systems in said first and second planes, said soft ferromagnetic material and said two systems of teeth in each stator section comprising part of a magnetic circuit which surrounds said annular coil of said stator sections, the axial distance between the teeth of said systems in one of said stator sections being at least a few times greater than the spacing between each system of stator teeth and the system of rotor teeth associated therewith, wherein each of said magnetic circuits which surround the annular coils consist of integrally manufactured laminations which are disposed in substantially axial planes.

A synchronous motor which comprises:

• first and second coaxial spaced stator sections, each stator section including at least one annular coil, each stator section being annular and including a plurality of teeth arranged in two circular systems on the inner surface of said stator, the number of teeth in all stator systems being equal and the spacing between adjacent teeth in all stator systems being uniform, said annular coils being each surrounded by a soft ferromagnetic material, said ferromagnetic material and said annular coils constituting a magnetic circuit, said motor further including a rotor having a geometric axis and first, second, third, and fourth circular axially spaced systems of teeth which each comprise a plurality of teeth which are uniformly spaced about the circumference of said rotor, the number of teeth in each of said systems being equal to the number of teeth in every other rotor system and also equal to the number of teeth in each system of teeth in said stator, said systems in said rotor being disposed respectively in first, second, third, and fourth planes which are disposed in substantially normal relationship to said geometric axis of said rotor, each plane in which one of said systems of said rotor is disposed also having one of said systems of said stator disposed therein, each of said systems of said rotor co-operating with one of said systems of said stator, said two systems of teeth in each of said stator sections being shifted angularly by substantially half of a tooth pitch relative to each other and said two stator sections being shifted angularly with respect to each other by substantially a quarter of a tooth pitch, said motor including a single permanent magnet which is disposed axially intermediate said stator sections and which magnetizes two systems of stator teeth which are in the same section and which are also in said first and second planes with substantially identical polarity distributions and two systems of teeth in the same section which are also in said third and fourth planes with substantially identical polarity distributions which are opposite to the polarity distributions of the systems in said first and second planes, said soft ferromagnetic material and said two systems of teeth in each stator section comprising part of a magnetic circuit which surrounds said annular coil of said stator sections, the axial distance between the teeth of said systems in one of said stator sections being at least a few times greater than the spacing between each system of stator teeth and the system of rotor teeth associated therewith, said permanent magnet being an axially magnetized permanent-magnetic ring, each of said magnetic circuits surrounding the annular coils of each stator sections each consisting of two parallel annular plates which are disposed in planes substantially perpendicular to the axis of the rotor, at the inner circumference of which said systems of teeth are formed and whose outer circumference adjoins the inner surface of a cylindrical ring belonging to said stator section, between which plates and the cylindrical ring the annular coil is included, both cylindrical rings extending as far as the permanent-magnetic ring and being provided with means for receiving the flux of the permanent-magnetic ring, so that between the two annular plates which face the permanent-magnetic ring and the permanent magnetic ring spaces are obtained with a magnetic resistance which is comparatively high relative to the magnetic resistance between the permanent-magnetic ring and the cylindrical ring.

A synchronous motor which comprises:

• first and second coaxial axially spaced stator sections, each stator section including at least one annular coil, each stator section being annular and including a plurality of teeth arranged in two circular systems on the inner surface of said stator, the number of teeth in all stator systems being equal and the spacing between adjacent teeth in all stator systems being uniform, said annular coils being each surrounded by a soft ferromagnetic material, said ferromagnetic material and said annular coils constituting a magnetic circuit, said motor further including a rotor having a geometric axis and four circular axially spaced systems of teeth which each comprise a plurality of teeth which are uniformly spaced about the circumference of said rotor, the number of teeth in each of said systems being equal to the number of teeth in every other rotor system and also equal to the number of teeth in each system of teeth in said stator, each of said systems in said rotor extending through a single plane which is disposed in substantially normal relationship to said geometric axis of said rotor, each plane which extends through one of said systems of said rotor also extending through one of said systems of said stator, each of said systems of said rotor co-operating with one of said systems of said stator, said two systems of teeth in each of said stator sections being shifted angularly by substantially half a tooth pitch relative to each other and said two stator sections being shifted angularly with respect to each other by substantially a quarter of a tooth pitch relative to each other, said stator including a single permanent magnet which is disposed axially intermediate said stator sections and which magnetizes both systems of stator teeth in said first stator section with a first polarity and both systems of teeth of said second stator section with a second polarity, said soft ferromagnetic material and said two systems of teeth in each stator section comprising part of a magnetic circuit which surrounds said annular coil of said stator section, the axial distance between the teeth of said systems in one of said stator sections being at least a few times greater than the spacing between each system of stator teeth and the system of rotor teeth associated therewith.