US Patent 10027195 Motor having cooling structure

A motor having a cooling structure includes: a motor shaft in which a cooling passage is formed in a center thereof in a lengthwise direction; a rotor disposed at an exterior circumference of the motor shaft to rotate together with the motor shaft; and a motor housing in which a stator fixed at a predetermined interval from the rotor is disposed at an interior circumference thereof and in which the motor shaft is disposed to be rotatable, wherein a coolant flowing through the cooling passage is jetted to the rotor or the stator.