| 摘要 |
In an e.g. permanent magnet electric motor, slots (3) are stamped in the sheet steel laminations forming the stator or rotor iron circuit to accommodate the winding (10). The magnetic flux is channelled to the air-gap through the teeth (2) thus formed. Each tooth is notched (8) near the tip, on either side, to receive the ends of the bridge-pieces (4), themselves stamped from the same sheet as the main laminations, which close the slot mouth over the whole length of the stator or rotor core. The correct assembly of these laminations is aided by holes stamped near each end whose rough edges, on one side, tend to bed into the slightly chamfered hole on the other face of the adjoining lamination. Bridging greatly reduces the variation in flux as each permanent magnet pole passes over the teeth. Corresponding reductions in eddy current loss allow the motor current to be increased, more than offsetting the loss of torque due to slot enclosure. Similar arrangements are described for motors with axial air-gaps. |
