Motor/generator and motor drive circuit

Apparatus for use as a motor or generator, comprising:

• a first part;
• a second part movable relative to the first part and spaced from the first part by an air gap;
• and
• a plurality of laterally spaced electromagnet elements provided on the first part, each electromagnet element being operative to apply a magnetic field in the air gap in response to application of an electric current;
• wherein each electromagnet element comprises:
• a pole piece comprising:
• an outer section defining an elongate air-gap facing surface of area A1, perimeter P1, lateral width W1, and longitudinal length L1, wherein L1 is greater than W1;
• and
• a coil-winding section of cross-sectional area A2, cross-sectional perimeter P2, lateral width W2, and longitudinal length L2;
• and
• an electrically conductive coil wound around the coil-winding section of the pole piece;
• wherein:
• P2 is less than P1 and W2 is substantially equal to L2;
• and
• the outer section has a first saturation level S1 and the coil-winding section has a second saturation level S2, wherein S2 is greater than S1.

Apparatus for use as a motor or generator, comprising:

• a first part;
• a second part movable relative to the first part and spaced from the first part by an air gap;
• and
• a plurality of laterally spaced electromagnet elements provided on the first part, each electromagnet element being operative to apply a magnetic field in the air gap in response to application of an electric current;
• wherein each electromagnet element comprises:
• a pole piece comprising:
• an outer section defining an elongate air-gap facing surface of area A1, perimeter P1, lateral width W1, and longitudinal length L1, wherein L1 is greater than W1;
• and
• a coil-winding section of cross-sectional area A2, cross-sectional perimeter P2, lateral width W2, and longitudinal length L2;
• and
• an electrically conductive coil wound around the coil-winding section of the pole piece;
• wherein:
• P2 is less than P1 and W2 is substantially equal to L2;
• and
• P2 is less than or equal to 0.9 times P1.

Apparatus for use as a motor or generator, comprising:

• a first part;
• a second part movable relative to the first part and spaced from the first part by an air gap;
• and
• a plurality of laterally spaced electromagnet elements provided on the first part, each electromagnet element being operative to apply a magnetic field in the air gap in response to application of an electric current;
• wherein each electromagnet element comprises:
• a pole piece comprising:
• an outer section defining an elongate air-gap facing surface of area A1, perimeter P1, lateral width W1, and longitudinal length L1, wherein L1 is greater than W1;
• and
• a coil-winding section of cross-sectional area A2, cross-sectional perimeter P2, lateral width W2, and longitudinal length L2;
• and
• an electrically conductive coil wound around the coil-winding section of the pole piece;
• wherein:
• P2 is less than P1 and W2 is substantially equal to L2;
• and
• W2 is greater than W1.