Rotating electric machine, elevator hoist, and method for magnetizing and demagnetizing permanent magnet of rotating electric machine

An elevator hoisting machine comprising:

• a rotating electric machine that is used as a motor for the hoisting machine;
• a first power source for armature coils;
• and
• a second power source for a non-armature coil, wherein
• the rotating electric machine comprises:
• a stator including an armature core including a back yoke having an annular shape, a plurality of magnetic pole teeth extending radially inward from the back yoke, and slots surrounded by the back yoke and the magnetic pole teeth, and
• a plurality of coils each of which is wound so as to straddle a plurality of the magnetic pole teeth and is disposed in the slots;
• and
• a rotor including a rotary shaft, a magnetic yoke provided on an outer peripheral side of the rotary shaft, and a plurality of permanent magnets disposed at certain intervals on an outer peripheral surface of the magnetic yoke, wherein
• the coils include armature coils for driving the rotating electric machine and a non-armature coil for magnetizing or demagnetizing the permanent magnets of the rotor.

A method for magnetizing or demagnetizing the permanent magnets of a rotating electric machine, comprising the steps of:

• passing a magnetizing or demagnetizing electric current through a non-armature coil;
• and
• rotating a rotor by a predetermined angle,
• the step of passing the magnetizing or demagnetizing electric current and the step of rotating the rotor being repeated, wherein
• the rotating electric machine comprises:
• a stator including an armature core including a back yoke having an annular shape, a plurality of magnetic pole teeth extending radially inward from the back yoke, and slots surrounded by the back yoke and the magnetic pole teeth, and
• a plurality of coils each of which is wound so as to straddle a plurality of the magnetic pole teeth and is disposed in the slots;
• and
• a rotor including a rotary shaft, a magnetic yoke provided on an outer peripheral side of the rotary shaft, and a plurality of permanent magnets disposed at certain intervals on an outer peripheral surface of the magnetic yoke, wherein
• the coils include armature coils for driving the rotating electric machine and a non-armature coil for magnetizing or demagnetizing the permanent magnets of the rotor.