Electric motor arrangement

• US 3,878,414 A
• Filed: 11/21/1973
• Issued: 04/15/1975
• Est. Priority Date: 11/22/1972
• Status: Expired due to Term

• Current Assignee: Mototaka Harakawa
• Original Assignee: Mototaka Harakawa
• Inventors: Harakawa, Mototaka
• Primary Examiner(s): Duggan, Donovan F.
• Application Number:
  US05/418,040
• Time in Patent Office: 510 Days
• Field of Search: 310/156,162-164,263
• US Class Current: 310/156.62
• CPC Class Codes: H02K 21/185 with the axis of the rotor perpendicular to the plane of the armature
• CPC Class Codes: H02K 21/20 having windings each turn of which co-operates only with poles of one polarity, e.g. homopolar machine

Abstract

An electric motor arrangement comprises a rotor being formed as a single rotatable disc made of soft magnetic material, the disc having a plurality of radially projecting rotor poles disposed equidistantly on its periphery, each of the rotor poles having a turn-up axial projection; a concentric disc-shaped permanent magnet being mounted fixedly to the lower surface of the disc; a rotor shaft, the disc and the permanent magnet being mounted fixedly on the rotor shaft; a stator plate consisting of a pair of parallel arms which form stator elements and are disposed at a 180*- offset manner, the arms having a plurality of diametrically opposed stator poles disposed concentrically to the disc, the stator poles being disposed with a pre-determined air gap from the rotor poles and arranged at equal pitches with the rotor poles; and an energizing coil being wound on one of the arms of the stator plate, the permanent magnet magnetizing the rotor poles to a pre-determined magnetic polarity and the stator poles to the opposite magnetic polarity thereby preventing fluxes flowing to the rotor poles and the stator poles from causing axial forces in the rotor shaft and thus providing a large torque to the rotor shaft at a small input power.

Claims

1. An electric motor arrangement comprising:

a rotor being formed as a single rotatable disc made of soft magnetic material, said disc having a plurality of radially projecting rotor poles disposed equi-distantly on its periphery, each of said rotor poles having a turned-up axial projection;

a concentric disc-shaped permanent magnet being mounted fixedly to the lower surface of said disc;

a rotor shaft, said disc and said permanent magnet being mounteD fixedly on said rotor shaft;

a stator plate consisting of a pair of parallel arms which form stator elements and are disposed in a 180* - offset manner, said arms having a plurality of diametrically opposite stator poles disposed concentrically to the disc, said stator poles being disposed across a pre-determined air gap from said rotor poles and arranged at equal pitches with said rotor poles; and

an energizing coil being wound on one of said arms of said stator plate, said permanent magnet magnetizing said rotor poles to a pre-determined magnetic polarity and said stator poles to the opposite magnetic polarity thereby preventing the fluxes flowing through said rotor poles and said stator poles from causing axial forces in said rotor shaft and thus providing a large torque to said rotor shaft at a small input power.

2. An apparatus arrangement comprising:

a rotor shaft;

a ring-shaped permanent magnet being mounted co-axially with said rotor shaft;

a drive pole plate made of soft magnetic material and having three projecting rotor poles disposed equi-distantly thereon, said drive pole plate being disposed concentrically on the lower surface of said permanent magnet;

an indexing pole plate having six projecting rotor poles disposed equi-distantly thereon, said indexing pole plate being mounted concentrically on the upper opposite surface of said permanent magnet;

a pair of stator elements having two diametrically pairs of projecting stator poles disposed concentrically to said projecting rotor poles of said drive pole plate, said stator poles being offset to said rotor poles of said drive pole plate at a certain angle, said stator poles being disposed across a pre-determined air gap from said rotor poles of said drive pole plate and arranged at equal pitches with said rotor poles thereof;

an energizing coil being wound on said stator elements;

a non-magnetic plate being formed with a round opening, said non-magnetic plate overlapping said pair of stator elements; and

an auxillary stator plate made of soft magnetic material and having three inwardly projecting stator poles, said auxillary stator plate being disposed in the common plane of said indexing pole plate and with air gaps relative thereto, said auxillary stator plate being mounted on said non-magnetic plate, said permanent magnet magnetizing said rotor poles of said drive pole plate and said stator poles of said auxillary stator plate, and magnetizing said rotor poles of said indexing pole plate and said stator poles of said stator elements to the opposite magnetic polarity, thereby preventing the fluxes flowing through said rotor poles of said drive pole plate, said stator poles of said auxillary stator plate, said rotor poles of said indexing pole plate and said stator poles of said stator elements from causing axial forces in said rotor shaft and thus providing a large torque to said rotor shaft at a small input power.

3. An electric motor arrangement comprising:

a rotor shaft;

two ring-shaped permanent magnets each of which is disposed radially at a certain distance from the axis of said rotor shaft;

a drive pole plate made of soft magnetic material and having three projecting rotor poles disposed equi-distantly thereon, said drive pole plate being disposed concentrically on said rotor shaft and on the lower surfaces of said permanent magnets;

an indexing pole plate having six projecting rotor poles disposed equi-distantly thereon, said an indexing pole plate being mounted concentrically on said rotor shaft and on the upper opposite surfaces of said permanent magnets;

a pair of stator elements having two diametrically projecting stator poles disposed concentrically to said projecting rotor poles of said drive pole plate, said stator poles being offset to said rotor poles at a certain angle, said stator poles being disposed across a pre-determined air gap from said rotor poles of said drive pole plate and arranged at Equal pitches with said rotor poles of said drive pole plate;

an energizing coil being wound on said stator elements;

a non-magnetic plate being formed with a round opening, said non-magnetic plate overlapping said pair of stator elements; and

an auxilliary stator plate made of soft magnetic material and having three inwardly projecting stator poles, said auxilliary stator plate being disposed in the common plane of said indexing pole plate and with air gaps relative thereto, said auxilliary stator plate being mounted on said non-magnetic plate, said permanent magnet magnetizing said rotor poles of said drive pole plate and said stator poles of said auxilliary stator plate to a pre-determined magnetic polarity, and magnetizing said rotor poles of said indexing pole plate and said stator poles of said stator elements to the opposite magnetic polarity thereby preventing the fluxes flowing through said rotor poles of said drive pole plate, said stator poles of said auxilliary stator plate, said rotor poles of said indexing pole plate and said stator poles of said stator elements from causing axial forces in said rotor shaft and thus providing a large torque to said rotor shaft at a small input power.