Electrical generator or motor structure – Dynamoelectric – Rotary
Patent
1996-02-02
1998-08-25
Stephan, Steven L.
Electrical generator or motor structure
Dynamoelectric
Rotary
310 49R, 310254, H02K 2908, H02K 3700
Patent
active
057985910
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to a motor or generator, in particular of a permanent magnet type, in which the rotor has magnetic poles with their polar axes arranged tangentially about the direction of rotation of the rotor and the stator coils enclose said poles.
BACKGROUND OF THE INVENTION
In the prior art, electromagnetic motors or generators are normally provided with a radial orientation of the magnetic fields of the stator and rotor. In addition the magnetic flux circuit of either the stator or rotor is enhanced by using a material having a high magnetic permeability. In such motors or generators there is energy loss due to eddy currents generated in this magnetic material, traditionally overcome by using laminations of the magnetic material.
Also the magnetic material has hysteresis losses and saturation of the iron circuit can occur at points within the magnetic circuit.
In addition, electromechanical devices employing a magnetic circuit normally have a disadvantage in weight since the known magnetic materials such as iron, nickel, or cobalt used in these devices are heavy, in addition to the problems stated above of any eddy current or hysteresis losses.
SUMMARY OF THE INVENTION
The present invention seeks to overcome some of these disadvantages in prior art machines or at least to ameliorate them, or to provide an alternative thereto.
According to a broad aspect of the invention there is provided an electromagnetic device of the type having a stator and a rotor, said rotor having a plurality of magnetic poles arranged about a radius of said rotor with their polar axes tangential to the said radius and said stator is an arrangement of stator coils in an open toroidal configuration enclosing said magnetic poles of said rotor.
The toroidal configuration of the stator coils is preferably of a C- or U-shape with the gap in the stator coil structure allowing the magnets of the rotor to be accommodated in the general torus thereby provided. Preferably, the magnetic poles are provided by permanent magnets which are arranged with like poles opposed.
The rotor may be made with no magnetic material, for example of a plastics material, or may be made of a conductive material such as aluminium or stainless steel. The permanent magnets may be embedded in or otherwise affixed to the rotor at the given radius from the centre of rotation of the rotor, for example at the periphery of the rotor, or may be positioned inwardly of the desired radial position with a magnetic or flux circuit conveying the magnetic field to the desired region, for example at the periphery, so that the magnetic poles of the rotor are within the toroidal space defined by the stator, preferably including the area of maximum field intensity of the stator coils.
The stator coils are made up of saddle shaped windings and are supported on a non-magnetic housing, for example, of a plastics material.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will now be described with respect to the following figures in which:
FIG. 1 shows a first embodiment of the invention;
FIG. 1a shows the general form of a stator coil according to the invention.
FIG. 2 shows a second embodiment of the invention;
FIG. 3 shows a third embodiment of the invention;
FIGS. 4-6 show schematically the operation of a three-phase, 4-pole motor according to the invention;
FIG. 7 shows a schematic illustrating a preferred arrangement of the permanent magnets according to the invention;
FIG. 8 shows the voltage output waveforms of a three-phase, 4-pole generator according to another embodiment of the invention;
FIG. 9 shows coil excitation waveforms for the embodiment of FIGS. 4-6;
FIG. 10 shows the performance for a motor with an 8-pole rotor according to the invention and
FIG. 11 shows a circuit diagram for electronically commutating the embodiment of FIGS. 4-6.
PREFERRED MODES FOR PERFORMING THE INVENTION
While the description and the embodiments to follow are of the operation of a motor and are described with respect to a pr
REFERENCES:
patent: 2623187 (1952-12-01), Adams
patent: 3330975 (1967-07-01), Osterwalder
patent: 3665227 (1972-05-01), Busch
patent: 3678311 (1972-07-01), Mattingly
patent: 3798526 (1974-03-01), Takahashi et al.
patent: 3922573 (1975-11-01), Whiteley
patent: 4141210 (1979-02-01), Flaig
patent: 4207483 (1980-06-01), Baer
patent: 4417167 (1983-11-01), Ishii et al.
patent: 4626698 (1986-12-01), Harnden, Jr. et al.
patent: 4704566 (1987-11-01), Hirano et al.
patent: 4731554 (1988-03-01), Hall et al.
patent: 4794293 (1988-12-01), Fujisaki et al.
patent: 4841189 (1989-06-01), Cooper
patent: 4922145 (1990-05-01), Shtipelman
patent: 5051641 (1991-09-01), Weh
patent: 5101131 (1992-03-01), Ushiro et al.
patent: 5107159 (1992-04-01), Kordik
patent: 5148069 (1992-09-01), Nonaka et al.
patent: 5214337 (1993-05-01), Ishibashi
patent: 5386166 (1995-01-01), Reimer et al.
Lillington David John
Lillington Paul Evan
Gallagher Thomas A.
Gordon David P.
Jacobson David S.
Nguyen Tran N.
Stephan Steven L.
LandOfFree
Electromagnetic machine with permanent magnet rotor does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electromagnetic machine with permanent magnet rotor, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electromagnetic machine with permanent magnet rotor will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-37925