Synchronous induction motor and electric hermetic compressor using the same

An electric hermetic compressor comprising:

• a hermetic housing;
• a synchronous induction motor in the hermetic housing, the synchronous induction motor including:
• a stator having a main winding and an auxiliary winding;
• a rotor having a yoke, a permanent magnet embedded in the yoke and a secondary conductor provided in a vicinity of a periphery of the yoke, and
• a starter including:
• a starting capacitor connected in series with the auxiliary winding;
• a positive temperature coefficient thermistor connected in series with the auxiliary winding and the starting capacitor;
• and
• a switching unit operable to close a circuit to the auxiliary winding from the starting capacitor when the synchronous induction motor is at rest, and operable to open the circuit and thereby cut off current flowing to the positive temperature thermistor after the synchronous induction motor is started;
• and
• a compression unit to be driven by the synchronous induction motor.

A synchronous induction motor comprising:

• a stator having a main winding and an auxiliary winding;
• a rotor having a yoke, a permanent magnet embedded in the yoke and a secondary conductor provided in a vicinity of a periphery of the yoke;
• and
• a starter including:
• a starting capacitor connected in series with the auxiliary winding;
• and
• a switching unit operable to close a circuit to the auxiliary winding from the starting capacitor when the synchronous induction motor is at rest, and to open the circuit after the synchronous induction motor is started, said switching unit including:
• a triac connected in series with the circuit;
• and
• a trigger circuit operable to control said triac.

An electric hermetic compressor comprising:

• a hermetic housing:
• a synchronous induction motor in the hermetic housing, the synchronous induction motor including:
• a stator having a main winding and an auxiliary winding;
• a rotor having a yoke, a permanent magnet embedded in the yoke and a secondary conductor provided in a vicinity of a periphery of the yoke;
• and
• a starter including:
• a starting capacitor connected in series with the auxiliary winding;
• and
• a switching unit operable to close a circuit to the auxiliary winding from the starting capacitor when the synchronous induction motor is at rest, and to open the circuit after the synchronous induction motor is started, said switching unit including:
• a triac connected in series with the circuit;
• and
• a trigger circuit operable to control the triac;
• and
• a compression unit driven by the synchronous induction motor.

A synchronous induction motor comprising:

• a stator having a main winding and an auxiliary winding;
• a rotor having a yoke, a permanent magnet embedded in the yoke and a secondary conductor provided in a vicinity of a periphery of the yoke;
• and
• a starter including:
• a starting capacitor connected in series with the auxiliary winding;
• and
• a switching unit operable to close a circuit to the auxiliary winding from the starting capacitor when the synchronous induction motor is at rest, and to open the circuit after the synchronous induction motor is started, said switching unit including:
• a bimetal switch connected in series with the circuit;
• and
• a heating element connected in parallel with the bimetal switch so as to thermally affect the bimetal switch.

An electric hermetic compressor comprising:

• a hermetic housing;
• a sychronous induction motor in the hermetic housing, the sychronous induction motor including:
• a stator having a main winding and an auxiliary winding;
• a rotor having a yoke, a permanent magnet embedded in the yoke and a secondary conductor provided in a vicinity of a periphery of the yoke;
• and
• a starter including:
• a starting capacitor connected in series with the auxiliary winding;
• and
• a switching unit operable to close a circuit to the auxiliary winding from the starting capacitor when the synchronous induction motor is at rest, and to open the circuit after the synchronous induction motor is started, said switching unit including:
• a bimetal switch connected in series with the circuit;
• and
• a heating element connected in parallel with the bimetal switch so as to thermally affect the bimetal switch;
• and
• a compression unit to be driven by the sychronous induction motor.

A synchronous induction motor comprising:

• a stator having a main winding and an auxiliary winding;
• a rotor having a yoke, a permanent magnet embedded in the yoke and a secondary conductor provided in a vicinity of a periphery of the yoke;
• and
• a starter including:
• a starting capacitor connected in series with the auxiliary winding;
• and
• a current relay operable to close a circuit to the auxiliary winding from the starting capacitor when the synchronous induction motor is at rest, and to open the circuit after the synchronous induction motor is started, the current relay including:
• a coil connected in series with the main winding;
• a movable contact driven by the coil;
• and
• a fixed contact connected in series with the circuit to attach the fixed contact.

An electric hermetic compressor comprising:

• a hermetic housing;
• a synchronous induction motor in the hermetic housing, the synchronous induction motor including:
• a stator having a main winding and an auxiliary winding;
• a rotor having a yoke, a permanent magnet embedded in the yoke and a secondary conductor provided in a vicinity of a periphery of the yoke;
• and
• a starter including:
• a starting capacitor connected in series with the auxiliary winding;
• and
• a current relay operable to close a circuit to the auxiliary winding from the starting capacitor when the synchronous induction motor is at rest, and to open the circuit after the synchronous induction motor is started, the current relay including:
• a coil connected in series with the main winding;
• a movable contact driven by the coil;
• and
• a fixed contact connected in series with the circuit to attach the fixed contact;
• and
• a compression unit to be driven by the synchronous induction motor.