Hitachi Appliances, Inc

Hitachi Industrial Equipment Systems Co., Ltd.

Japan Servo Co.,ltd.

Hitachi Powdered Metals Co., Ltd.

Akeshi Takahashi

Tomio Yoshikawa

Satoshi Kikuchi

Haruo Koharagi

Baiying Huang

Keiji Tanaka

Ryoso Masaki

Yuji Enomoto

Kenji Tojo

Katsuyuki Yamazaki

Motoya Ito

Masashi Kitamura

Chio Ishihara

Hiroyuki Mikami

Shigekazu Nozawa

Yasuaki Motegi

Shoji Ohiwa

Kazuo Asaka

Masaru Ohtahara

Masashi Miyake

Yasuro Ohishi

Hideyuki Kumakura

Masahide Yamazaki

Baiying Hang

Susumu Nakayaka

A self-starting type permanent magnet synchronous motor comprises a stator and a rotor. The rotor comprises a rotor core having a plurality of slots provided in an outer periphery thereof and a cage winding comprising conductive bars embedded in the slots and conductive end rings that short-circuit the conductive bars on both end faces of the bars in an axial direction thereof. The rotor core comprises at least one magnet insertion hole arranged on an inner peripheral side from the slots, and at least one permanent magnet embedded in the at least one magnet insertion hole. When a pole center axis is denoted as a d-axis and an axis deviating from the pole center axis by an electrical angle 90&#xb0; is denoted as a q-axis, a flux content generated by the cage winding during start-up becomes maximal in the vicinity of and on one of the d-axis and the q-axis.

Self-starting type permanent magnet synchronous motor and a compressor using the same

The inventive self-initiated permanent magnet synchronous motor has a rotor that has two-pole permanent magnets, as well as magnetic substances in a peripheral direction between the magnetic poles of the permanent magnets. The present invention provides a high-efficiency, high-torque permanent magnet synchronous motor with an improved power factor, its rotor, and a compressor using the permanent magnet synchronous motor, without a reduction in the maximum torque and an increase in costs.

Permanent magnet synchronous motor, rotor of the same, and compressor using the same

A three-phase permanent magnet brushless motor comprises a stator having three-phase windings, and a rotor having a permanent magnet with a plurality of poles for serving as a field magnet. The stator comprises a stator core which includes a powder core that is compacted at a high density in at least teeth thereof. A combination of the number of magnetic poles of the rotor with the number of slots of the stator satisfies a condition that a least common multiple of the number of slots and the number of magnetic poles is 60 or more in a region in which the number of magnetic poles is 16 or less, and the number of slots is 12 or less. The powder core is made by compacting magnetic powders to have a green density of 7.5 g/cmor higher.

Three-phase permanent magnet brushless motor

In a method of manufacturing a self-start synchronous motor for preventing deterioration of permanent magnets used in a rotor, and also for enhancing the efficiency of the self-start synchronous motor, the self-start synchronous motor comprising a stator having a stator core and windings wound around the stator core, and a rotor having an outer diameter slightly smaller than an inner diameter of the stator and arranged inside of the stator. The rotor is provided with a rotor core, a plurality of conductor bars embedded in the outer peripheral portion of the rotor core over an entire periphery thereof, end rings provided on opposite end sides of the conductor bars and constituting a squirrel cage conductor in cooperation with the conductor bars, and a plurality of permanent magnets embedded in the rotor core and arranged at a position inner than that of an inner peripheral surface of the conductor bars. Further, the conductor bars and the end rings are electrically and mechanically joined together through frictional agitation joint.

Self-start synchronous motor with permanent magnets and at least one frictional agitation joint, method for manufacturing the same and compressor comprising the same

The invention provides a motor comprising a stator and a rotor. The stator core includes a laminated stator core made of laminated stator core plates in which straight cut surfaces are formed on a circular outer peripheral surface of the laminated stator core plates. The straight cut surfaces of the laminated stator core plates are circumferentially displaced every predetermined laminated stator core plates so that the straight cut surfaces are uniformly distributed in an axial and a circumferential direction of the laminated stator core. Therefore, a flow passage for lubricating oil is ensured, while local magnetic saturation of the stator core is dissolved and a cogging torque and an induced voltage waveform distortion rate are improved.

Motor, compressor, and air conditioner

A permanent magnet synchronous motor includes a rotor having cage windings and permanent magnets placed on an inner peripheral side of these cage winding bars, where the permanent magnets are placed and polarized so that a ratio &#x3b8;/&#x3b1; between a circumferential pitch angle &#x3b8; of magnetic flux distribution of the permanent magnets and a magnet pole pitch angle &#x3b1; is between 0.67 and 0.91.

Permanent magnet synchronous motor and compressor using the same

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Hitachi, Japan

Akeshi Takahashi