Abstract: The invention provides a power tool, a motor and a rotor assembly of the motor. The rotor assembly includes a rotating shaft, and a rotor body, a limiting member and a cooling fan fixed on the rotating shaft, the limiting member and the cooling fan are respectively arranged at both axial ends of the rotor body, the rotor body includes a rotor core and magnets fixed in the rotor core, the limiting member and the cooling fan jointly limit an axial displacement and a radial displacement of the magnets.

Abstract: A stator, a bobbin and a method for positioning a thermistor are provided. The bobbin can be fixed on a stator core of the stator and includes a ring shaped stop plate and a plurality of winding portions extending downward from a sidewall of the stop plate. A positioning groove is defined in the sidewall of the stop plate toward one of the winding portions for accommodating the thermistor, the positioning groove opens toward the one of the winding portions.