The single-phase induction motor with a short-circuit auxiliary winding stands out among single-phase induction motors, because of its simplest, reliable and economical starting method. https://www.mrosupply.com/v-belts/v-belts/a-section/178198_a74_gates-rubber/ One of the most common constructive forms is that of protruding poles, of which 25 to 35% of each pole is connected by a shorted copper loop. The direction of rotation will depend on the side that is located the part of the pole, so the distorted field motor will have a single direction of rotation.
The direction of rotation can be reversed by changing the position of the rotor shaft tip relative to the stator. The distorted field motors have low starting torque (15 to 50% of nominal), low efficiency (35%) and low power factor (0.45). The current induced in the loop causes the flow that crosses it to suffer a delay in relation to the flow of the part not connected by the same. The result of this is similar to a rotating field that moves in the direction of the non-entangled part to the bonded part of the pole, causing the torque which will cause the motor to break and achieve nominal rotation.