Hitachi Industrial Equipment Systems Co., Ltd.

Hitachi, Ltd.

Masaharu Senoo

Toshiyuki Ajima

Hideharu Tanaka

Satoshi Kikuchi

Hirotaka Kameya

Masaru Yamasaki

Ryoichi Takahata

Norinaga Suzuki

Shinichi Wakui

Keiji Noma

Koji Obata

Takashi Yasuhara

Takayuki Koizumi

Takeshi Obata

Akira Saruta

Masanori Yoshizaki

Kouei Yaegashi

Koichi Teshirogi

Keizi Noma

Akihiro Sekine

Mituru Itou

An oil-flooded screw compressor drives a pair of rotors at a rotational speed which is low enough not to increase torque for a short amount of time after start-up and accelerates the pair of rotors up to a normal-operation rotational speed after oil discharge. Alternatively, the oil-flooded screw compressor rotates the pair of rotors for a short amount of time after the remaining compressed gas is discharged after a halt, thereby allowing the oil accumulated inside the working chambers to be discharged and ensuring smooth start-up after the halt.

Oil-flooded screw compressor, motor drive system, and motor control

Oil-flooded screw compressor, motor drive system, and motor control device

A permanent magnet type electric rotary machine includes a stator including a stator core having teeth and slots, and a rotor provided with permanent magnets as magnet poles in a rotor core. A pole core portion which between each of the permanent magnets and an outer surface of the rotor core is provided with a plurality of pole slits. A region of the pole core portion is defined by concave portions provided on q-axes to be interpolars on both sides of the pole core portion, and thereby configured that a gap between the outer surface on the q-axis of the rotor core and an inner surface of the stator core is larger than a gap between the outer surface on the d-axis of the pole core portion and the inner surface of the stator, so that magnetic fluxes from the permanent magnet pass through the pole core portion concentrately.

Permanent magnet type electric rotary machine and compressor using the same

A rotating electric machine includes a stator core of a cylindrical shape, a rotor core coaxially rotating inside the stator core, and a plurality of coils each formed by winding magnet wires using a slot formed axially in either the stator core or the rotor core, or both: it is preferable that each of the coils be split into a plurality of coil groups, that starting sections of winding of the magnet wires in one of the coil groups be wound adjacently to ending sections of winding of the magnet wires in another of the coil groups, and that the starting sections and ending sections of winding of the magnet wires in the two coil groups be connected at respective outgoing wire ends to one another, outside the slots.

Rotating electric machine, winding machine, and rotating electric machine system

A novel rotor construction is disclosed, in which plural permanent magnets are arranged on the outer periphery of a rotor core, which are protected with a cover, and in which a member is placed at an axial end of the rotor core cast with end rings with a balance weight on the outside thereof. The protective cover protects the outer peripheries of the end rings and dampens the centrifugal force of the balance weight. Projections provided on the outer periphery of the member are located at the center of the permanent magnets to reduce the leakage magnetic fluxes between the permanent magnets.

Reinforced permanent magnet rotor with cast zinc

Growing community of inventors

Narashino, Japan

Masaharu Senoo