Slot opening width

The slot opening width is the distance between two tooth tips.

The slot opening width is the distance between two tooth tips. As you can see in the example shown in Fig. 1, this distance is constant along the entire tooth tip depth.

Fig. 1 Illustration of slot opening width.

By increasing the slot opening width, the slot leakage reduces and more flux will be coupled between rotor and stator. In addition, it will be easier to insert the conductors into the slots during manufacturing.

By decreasing the slot opening width, the reluctance variation seen by the rotor will be lower which might reduce the cogging torque and eventually the torque ripple. A small slot opening width does also increase the slot leakage, which might be a desirable feature when your machine is designed to operate under field-weakening condition (traction applications).

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