Electrical generator or motor structure – Dynamoelectric – Rotary
Patent
1992-04-22
1995-03-07
Stephan, Steven L.
Electrical generator or motor structure
Dynamoelectric
Rotary
H02K 112
Patent
active
053961382
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention relates to electric motors.
The invention relates more particularly to a brush-less direct current electric motor. Such motors comprise a stator core formed of a stack of laminations held in a housing, having a stator winding positioned inside the stack and a magnetic rotor rotatably mounted inside the winding. The manufacture of the laminations and their formation and accurate positioning in the motor configuration which requires accurate stamping to produce the laminations and often post-stamping machining to remove edge burrs, is wasteful of material, and generally leads to relatively slow production methods.
BRIEF DESCRIPTION OF THE INVENTION
According to the one aspect of the invention there is provided a permanent magnet direct current electric motor including a stator core, a stator winding for the stator core, and a magnetic rotor rotatably mounted inside the stator core, in which the stator core comprises a closely wound helical coil of ferromagnetic wire, and in which the stator winding is positioned between the stator core and the rotor.
An embodiment of the invention may comprise a permanent magnet direct current electric motor including a stator core, a preformed cylindrical stator winding for the stator core, and a magnetic rotor rotatably mounted inside the stator winding, in which the stator core comprises a closely-wound helical coil of ferromagnetic wire which fits snugly over the winding having a mean inside diameter substantially equal to the outside diameter of the winding, the coil being arranged to be fitted to the winding by rotating one of its ends relative to the other to increase its inside diameter and sliding the coil over the winding.
The coil of ferromagnetic wire may be formed by at least two separate wires and formed as a multi-start coil.
The ferromagnetic wire may have a rectangular cross-section and for example be square in cross-section.
The ferromagnetic windings of the coil may be held together by one or more joining seams extending axially along the outside of the coil. The seams may be formed by welding.
The electric motor may include a magnetic material housing surrounding and in close proximity to the stator core.
The ferromagnetic wire may be coated with an electrically insulating material. The wire may be aluminium and the coating comprise alumina.
According to another aspect of the invention there is provided a method of assembling a permanent magnet direct current electric motor having a stator core, a preformed stator winding and a magnetic rotor rotatably mounted inside the stator winding, in which the stator core comprises a closely-wound helical coil of resilient ferromagnetic wire, the method comprising gripping the ends of the coil and relatively rotating the ends to increase the mean inside diameter of the coil, sliding the coil relative to the winding to fit the coil to the winding, and releasing the ends of the coil to allow the coil to relax and bear against the winding.
The method may include gripping the ends of the coil and relatively rotating the ends of the coil to decrease the mean diameter of the coil together with the winding inside the coil, sliding the coil and winding inside a casing which fits over the coil, and releasing the ends of the coil to allow the coil to relax and bear against the inside of the casing.
The method may include gripping the ends of the coil and relatively rotating the ends of the coil to decrease the mean diameter of the coil together with the winding inside the coil, and sliding the coil and winding inside a mould.
BRIEF DESCRIPTION OF THE DRAWINGS
A brushless fractional horsepower direct current motor according to the invention will now be described by way of example with reference to the accompanying diagramatic drawings in which:
FIG. 1 is an exploded view of the motor;
FIG. 2 is a cross-sectional view of motor; and
FIG. 3 is an isometric view of another stator core for the motor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, in FI
REFERENCES:
patent: B521044 (1976-02-01), Sims
patent: 4392072 (1983-07-01), Rosenberry
patent: 4543507 (1985-09-01), Heyraud
patent: 4612470 (1986-09-01), Smith, Jr. et al.
patent: 4837921 (1989-06-01), Tassinario
patent: 4987331 (1991-01-01), Horng
Patent Abstracts of Japan, vol. 14, No. 297 (E-945) (4240) 27 Jun. 1990-Japan 2,095,147 (Hitachi) 5 Apr. 1990.
Patent Abstracts of Japan, vol. 10, No. 133 (E-404) (2190) 17 May 1986-Japan 60 261 334 (Inoue Japax) 24 Dec. 1985.
Patent Abstracts of Japan vol. 12, No. 425 (E-681) (3272) 10 Nov. 1988-Japan 63 161 827 (Matsushita) 5 Jul. 1988.
Patent Abstracts of Japan vol. 8, No. 74 (E-236) (1511) 6 Apr. 1984-58 222 745 (Shibaura) 24 Dec. 1983.
Patent Abstracts of Japan vol. 8, No. 63 (E-233) (1500) 24 Mar. 1984-58 212 360 (Shibaura) 10 Dec. 1983.
Johnson Electric S.A.
Nguyen Matthew
Stephan Steven L.
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