Abstract: An airtight-type electric motor capable of reducing vibration is provided. Inside ribs of a pair of end brackets and are respectively fitted into core end portions of a stator core. Outside ribs of the pair of end brackets and are respectively brought into contact against end surfaces of the core end portions of a yoke of the stator core. With this arrangement, the pair of end brackets and are fixed to the stator core, and a housing and the stator core are arranged, without being coupled together.

Abstract: An airtight-type electric motor capable of reducing vibration is provided. Inside ribs of a pair of end brackets and are respectively fitted into core end portions of a stator core. Outside ribs of the pair of end brackets and are respectively brought into contact against end surfaces of the core end portions of a yoke of the stator core. With this arrangement, the pair of end brackets and are fixed to the stator core, and a housing and the stator core are arranged, without being coupled together.

Abstract: A rotation control method of a synchronous motor, the motor comprising: a stator having AC windings thereround; and a rotor, being mounted within said stator, rotatably, wherein on an each surface, opposing to the rotor, of poles building up the stator, are formed plural numbers of teeth portions, and on a surface of the rotor, being made of permanent magnet, opposing to the poles of the stator, are also formed plural numbers of teeth portions, with a width being nearly equal to that of the teeth portion in a circumference direction thereof, and further AC voltages having a predetermined voltage-frequency characteristic is supplied to AC windings wound around the poles of the stator, and the AC voltages supplied from the inverter is so determined in the voltage-frequency characteristic thereof, at least within a part of frequency band equal or less than a predetermined rated frequency, a pull-out torque of the synchronous motor is equal to or greater that a rated pull-out torque at the predetermined rated fre

Abstract: A rotation control method of a synchronous motor, the motor comprising: a stator having AC windings thereround; and a rotor, being mounted within said stator, rotatably, wherein on an each surface, opposing to the rotor, of poles building up the stator, are formed plural numbers of teeth portions, and on a surface of the rotor, being made of permanent magnet, opposing to the poles of the stator, are also formed plural numbers of teeth portions, with a width being nearly equal to that of the teeth portion in a circumference direction thereof, and further AC voltages having a predetermined voltage-frequency characteristic is supplied to AC windings wound around the poles of the stator, and the AC voltages supplied from the inverter is so determined in the voltage-frequency characteristic thereof, at least within a part of frequency band equal or less than a predetermined rated frequency, a pull-out torque of the synchronous motor is equal to or greater that a rated pull-out torque at the predetermined rated fre