Variable magnetic flux electric rotary machine

An electric rotary machine comprising:

• a stator having a winding;
• a triple rotor which is rotatably disposed with a gap from the stator and divided axially along a shaft into a first rotor, a second rotor and a third rotor each having field magnets with different polarities arranged alternately in a rotation direction;
• and
• a mechanism for varying axial positions of the second rotor and the third rotor relative to the first rotor continuously.

An electric rotary machine comprising:

• a stator having a winding;
• a rotor which is rotatably disposed with a gap from the stator and divided axially along a shaft into four or more sub-rotors each having field magnets with different polarities arranged alternately in a rotation direction;
• and
• a control mechanism for controlling rotation of each rotor.