Hitachi, Ltd.

Fumio Jyoraku

Yoshitaro Ishii

Hisanori Toyoshima

Kunio Miyashita

Kazuo Tahara

Haruo Koharagi

Tsunehiro Endo

Syuji Watanabe

Wakichiro Hishi

Koujirou Yamashita

Kohichi Saito

Satoshi Kikuchi

Hiroyuki Mikami

Tsukasa Taniguchi

Hisao Suka

Mitsuhisa Kawamata

Hideyuki Harada

Takeshi Abe

Toshiyuki Ajima

Masao Sunagawa

Tunehiro Endo

Shigenori Sato

Atusi Hosokawa

Motoo Futami

Hisanori Okamura

Masahisa Inagaki

Yasuhisa Aono

Sadashi Tanaka

Yukiji Iwase

Kouichi Saito

Kiyomi Nakamura

Shoichi Ito

Susumu Sato

Taiji Tajima

Shoji Hayashi

Shigetaka Kimura

Kazuyuki Sugimura

Takeshi Obana

Kohichi Hasegawa

Susumu Satoo

Jiro Arai

Hisanori Toyosima

Takayuki Sudou

Ryuji Ikeda

A permanent magnet rotating electric machine has a stator provided with a plurality of windings, and a rotor in which magnets are disposed in slots formed in a rotor core along an outer circumference thereof. The rotor core is fixed on a rotary shaft rotating inside the stator, and one magnetic pole is constituted by each group of three or more of the magnets. A total angle occupied by the group of magnets constituting one magnetic pole is in the range of 150 to 165 degrees in terms of an electrical angle.

Rotor of permanent magnet rotating electric machine

In the prior art in which permanent magnets are regularly arranged over the whole circumference of a rotor core, a satisfactory magnetic flux distribution is hard to obtain, and the cogging torque and the distortion factor of the induced electromotive force waveform are large, whereby characteristics of a rotating electric machine are poor. Also, because the permanent magnets are arranged over the whole circumference, a large number of permanent magnets are required and cost reduction is difficult. A permanent magnet rotating electric-machine of the invention comprises a stator provided with a plurality of windings, and a rotor in which magnets are disposed in slots formed in a rotor core along an outer circumference thereof, the rotor core being fixed on a rotary shaft rotating inside the stator, and in which one magnetic pole is constituted by each group of three or more of the magnets. A total angle occupied by the group of magnets constituting one magnetic pole is in the range of 150 to 165 degrees in terms of an electrical angle.

A vacuum cleaner includes a vacuum cleaner body in which a rotating brush, a dust collecting unit and an electric blower unit are integrally attached to a suction opening casing in which a brush chamber is formed. A rodlike handle is connected to the vacuum cleaner body. The rodlike handle is formed by a hollow member, and a plurality of batteries are arranged in series in the hollow member and are covered with a heat contraction tube.

Vacuum cleaner

Reduction of air resistance which acts on the conventional motor-driven blower is limited because crushed protrusions are formed on the surface of the plate of the impeller of the conventional motor-driven blower, and this air resistance is a significant impediment to an increase of the operating speed of the motor-driven blower. Thus, an impeller is provided which comprises a front plate having a suction opening, a back plate disposed opposite to the front plate, and a plurality of blades disposed between the front plate and the back plate. At least either the front plate or the back plate is formed integrally with the blades.

Motor-driven blower and method of manufacturing impeller for

A controlling apparatus controls a suction performance of a blower motor which is installed into a cleaner main body. The controlling apparatus increases the suction performance when a suction nozzle is operated and decreases the suction performance when the suction nozzle is stopped. Corresponding to a floor use suction nozzle and a crevice use suction nozzle, at a predetermined air flow amount range, the most suitable operation control being suited to a discriminated suction nozzle can carried out automatically. Plural kinds of the suction nozzles at an actual use scope are set beforehand. When the suction nozzle is exchanged the flow amount range is changed over and selected with a respective suction nozzle. Plural kinds of the suction nozzles are selected and changed over automatically according to the dimension of a change amount of an operation condition. A brushless direct motor is used as the blower motor and has a domain being operated at a chopper control duty of factor 100%.

Method and apparatus for operating a vacuum cleaner in which by detecting a rotational speed of a variable speed fan motor adapted to give a suction force to the cleaner and its change range, the choking state of the filter and the state of the cleaned surface are discriminated, and a speed command of the fan motor is corrected on the basis of the result of the discrimination, and the comfortable cleaning can be performed by the optimum suction force.

Method and apparatus for operating vacuum cleaner

In a vacuum cleaner, both static pressure H.sub.data and a variation width .DELTA.H in the static pressure appearing when a suction port is operated are detected from a pressure sensor provided at a rear side of a filter within a main body of the vacuum cleaner; a current variation width .DELTA.pbi appearing when the suction port is operated is detected from a current of a nozzel motor for driving a rotary brush stored in a power brush suction port; an air quantity at the suction port is calculated from the current, rotational speed of a fan motor and static pressure; command values are newly obtained by performing a fuzzy calculation with the variation width .DELTA.pbi, static-pressure command value Hcmd; the variation width .DELTA.H and the static-pressure command value Qcmd; the variation width .DELTA.pbi and static-pressure command value Hcmd; and also the variation width .DELTA.H and static-pressure command value Qcmd as the input thereto; the rotational speeds of the fan motor and nozzel motor are controlled from the result of the command values; and further optimum air suction force is automatically obtained, depending upon the suction port under use and cleaning floor plane.

Vacuum cleaner with fuzzy logic control

Motor control apparatus for an electric vacuum cleaner

An electric blower has an electric motor, a centrifugal impeller rotating by the driving of the electric motor, an end bracket for separating the electric motor from the centrifugal impeller, and a diffuser. The diffuser includes a plurality of diffuser vanes arranged near the outer periphery of the centrifugal impeller, and a flat plate portion which extends between the centrifugal impeller and the end bracket for supporting the diffuser vanes. The flat plate portion has a plurality of guide vanes formed on an opposite surface thereof from the diffuser vanes. A passage is defined by the end bracket, the flat plate portion and the guide vanes so as to return the air flow, discharged from the centrifugal impeller through the diffuser vanes, inwardly of the blower. The end bracket is formed in a substantially convex shape so as to extend away from the flat plate portion of the diffuser, with the end bracket extending from a central portion toward its periphery, thereby defining an opening area of the discharge air flow return passage. A sound absorbing material is arranged in the discharge air flow return passage to absorb sounds from the discharging air flow.

Electric blower having improved return passage for discharged air flow

A vacuum cleaner comprising a fan motor disposed in a main body case thereof and having a motor with a permanent magnet stator or rotor, and a fan arranged to be rotated by the motor. A dust-collecting chamber collects dust suctioned into the main body case due to the rotation of the fan motor, and a dust-collecting filter causes the dust suctioned into the main body case to be caught in the dust-collecting chamber. A magnetic material adhesion preventing device is provided in a passage through which air flows due to rotation of the fan motor, with the magnetic material adhesion preventing device acting to prevent adhesion of fine dust composed of magnetic materials included in the air flow to a portion in the vicinity of the permanent magnet. As a result, adhesion of fine dust between the rotor and stator can be prevented thereby increasing the service life and the reliability of the vacuum cleaner.

Method and apparatus for operating a vacuum cleaner in which by detecting a rotational speed of a variable speed fan motor adapted to give a suction force to the cleaner and its change range, the choking state of the filter and the state of the cleaner surface are discriminated, and a speed command of the fan motor is corrected on the basis of the result of the discrimination, and the comfortable cleaning can be performed by the optimum suction force.

In a vacuum cleaner comprising an electric blower and a speed control unit to operate the electric blower at a variable speed, a plurality of kinds of operation control rules of the electric blower are previously stored in the speed control unit, a load current value of the electric blower is continuously detected during the cleaning and the type of the surface to be cleaned is estimated from the load current value. Thereafter, the operation control rule suitable for the estimated cleaning surface is selected from the operation control rules stored in the speed control unit and the electric blower is driven on the basis of the selected operation control rule.

A vacuum cleaner comprises a vacuum cleaner body in which at least a dust collecting chamber, an electric blower chamber, and an exhaust chamber are formed integrally and an accommodating case for accommodating the vacuum cleaner body and attachments of the vacuum cleaner, and a suction opening and an exhaust opening are provided in the accommodating case which includes a body case accommodating at least the vacuum cleaner body and a cover case for covering an opening of the body case, with the result that a portable, compact vacuum cleaner is provided.

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Hitachi, Japan

Fumio Jyoraku