Rotary electrical machine

1. A rotary electrical machine, comprising:

a first annular body and a second annular body facing opposite each other;

a coil interposed between the first annular body and the second annular body;

a permanent magnet mounted on one of the first annular body and the second annular body;

a rotating shaft having an axis;

both of said first annular body and said second annular body being capable of rotating about an axis of the rotating shaft provided commonly to said first annular body and said second annular body;

said first annular body or said second annular body on which said permanent magnet is mounted being rotatable about the axis of said rotating shaft together with said permanent magnet that is rotated when said coil is energized so that it can be conducted electrically in a magnetic field developed by said permanent magnet between said first annular body and said second annular body; and

the driving force of a motor being extracted through said rotating shaft which rotates with said first annular body or said second annular body while it is rotating, wherein:

a driving force of the motor is extracted via said rotating shaft which rotates with said first annular body, while said second annular body is arranged rotatably with regard to said rotating shaft independently of the rotations of said rotating shaft and said first annular body; or

a driving force of the motor is extracted via said rotating shaft which rotates with said second annular body, while said first annular body is arranged rotatably with regard to said rotating shaft independently of the rotations of said rotating shaft and said second annular body.

2. The rotary electrical machine as defined in claim 1 , wherein

said rotating shaft is supported within a housing;

said first annular body is arranged concentrically relative to said rotating shaft;

said second annular body is arranged concentrically relative to said rotating shaft and is located inside or outside said first annular body in a radial direction of said rotating shaft;

said coil is arranged concentrically on said rotating shaft and is located between said first annular body and said second annular body; and

said permanent magnet is arranged on a circumferential side of either of said first annular body and said second annular body facing opposite the other corresponding second annular body or first annular body.

3. The rotary electrical machine as defined in claim 1 , wherein

said rotating shaft is supported rotatably within a housing;

said coil is supported within said housing;

said first annular body and said second annular body are arranged so that they can face opposite each other in the axial direction of said rotating shaft in which it is extended and with said coil interposed therebetween;

either of said first annular body and said second annular body is supported rotatably with regard to said rotating shaft and the other corresponding second annular body or first annular body is supported on said rotating shaft;

said rotating shaft is rotated by causing said first annular body or said second annular body that is supported rotatably on said rotating shaft to be rotated about the axis of the rotating shaft; and

the driving force of the motor is extracted through said rotating shaft while it is rotating.

4. The rotary electrical machine according to claim 1 , wherein the first annular body and the second annular body are each configured so the rotating force by one of the first annular body and the second annular body will not be transferred to the other of the first annular body and the second annular body.