Air cooling apparatus having an expander driven by a power transmission using a rotating magnetic field

An air cooling apparatus comprising:

• an electric motor;
• an expander rotating by rotation power of the electric motor to expand air;
• an expander housing surrounding the expander;
• and
• a power transmission device interposed between the electric motor and the expander housing to transmit the rotation power to the expander,
• wherein the power transmission device comprises a power generator;
• and a front driver module and a rear driver module disposed at a front and a rear side of the power generator to form magnetic fields around a front rotor and a rear rotor of the power generator, the power generator being mounted with the expander on a shaft of a bearing module, the power generator being mounted with the rear driver module and the expander housing spaced apart from the rear rotor by a predetermined rear gap in an axial direction of a frame, a width of the rear gap disposed in a direction orthogonal to the rear rotor, and the power generator being disposed in a direction orthogonal to the rear rotor at a rear side of the frame, a front side of the frame being mounted on the electric motor, and the front driver module being spaced from the front rotor by a predetermined front gap in the axial direction of the frame, a width of the front gap disposed in a direction orthogonal to the front rotor, and the front driver module being disposed in a direction orthogonal to the front rotor at the front side of the frame and being mounted on a shaft of the electric motor to receive the rotation power of the electric motor, and
• the front rotor and the rear rotor of the power generator face the front driver module and the rear driver module, permanent magnets included in the front rotor and the rear rotor generating magnetic fluxes, and permanent magnets included in the front driver module and the rear driver module generating magnetic fluxes such that a rotating magnetic field generated by rotation of the front driver module, a rotating magnetic field generated by the power generator and a magnetic field of the rear driver module form a rotational force with the interaction of an attractive force and a repulsive force to transfer the rotation power of the motor to the expander,
• wherein the power generator comprises:
• the frame;
• the bearing module mounted on the frame;
• the front rotor and the rear rotor disposed in a direction orthogonal to a front and a rear face of the frame, and spaced from the front and rear faces in an axial direction by a predetermined gap, the front and rear rotors being fixed to the shaft of the bearing module, allowing the permanent magnets of the front and rear rotors to be arranged in an axial diameter direction while being spaced by the predetermined gap in an axial direction of the shaft of the bearing module and disposed in an orthogonal direction of the frame;
• a driver module spaced from the front rotor and the rear rotor by the predetermined gap in an axial direction of the shaft of the bearing module and disposed in an orthogonal direction such that permanent magnets included in the driver module are arranged around the front rotor and the rear rotor in an axial diameter direction, and mounted onto the frame;
• lock nuts for fixing the front rotor and the rear rotor to the bearing module;
• and
• a fixture for fixing the bearing module to the frame.