Is there any technical reason behind it to keep the air gap between the rotor and stator of a 3-phase induction motor small or this is for design purpose.
If you study the operation principle of induction motors, you'll realize, that the air gap has a large impact on the achievable power factor and efficiency of a motor.
If you study the operation principle of induction motors, you'll realize, that the air gap has a large impact on the achievable power factor and efficiency of a motor.