Hitachi, Ltd.

Other

Nissan Motor Company Limited

Michiyuki Takagi

Osami Matsushita

Yasushi Takano

Yoshihiro Nagaoka

Sadashi Tanaka

Yukiji Iwase

Michiaki Ida

Yoshiharu Ueyama

Toyomi Yoshida

Mitsuho Yoneyama

Tetsuya Yoshida

Toyomi Sugaya

Fumio Tajima

Kenichi Murata

Takeshi Kudo

Kazuhiro Komatsu

Naohiko Takahashi

Kazuyuki Yamaguchi

Toshiki Iino

Masahide Kimura

Yohei Magara

Yasushi Fujita

Tsukasa Yamazaki

Kanako Nemoto

Ikuhiro Saitoh

Shunji Ooki

Akira Nezu

Hiromi Kaneko

Ikuhiro Saito

A turbomachinery includes a labyrinth seal () to prevent unstable vibration of a rotor formed by dividing the seal into segments () in a circumferential direction and combining the segments () whose comb teeth () differ in height. The labyrinth seal () preferably includes two kinds of segments () whose comb teeth () differ in height for each kind of segment, and the segments () of the greater comb tooth height are arranged in a certain reference direction on a cross section right-angled to a rotational axis, and in a direction opposite to the reference direction, and the segments () of the smaller comb tooth height are arranged in a direction right-angled to the reference direction, and in a direction opposite to that right-angled to the reference direction.

Turbomachinery

The vibration and noise excited by the electromagnetic exciting force in the radial direction of an electric motor are suppressed. In an electric motor, a rotoris divided into four rotor pieces, andfor an axial length of 2L of one group of the rotor core, and for example, the four rotor pieces, andare ideally 0.29L, 0.71L, 0.71L, and 0.29L in axial length in the axial direction, and permanent magnetsof the rotor pieces, andare arranged in the circumferential direction so that the phase differences of the electrical angle are 0, &#x3c0;, 0, and &#x3c0;. Further, when an effect is obtained even if the ideal axial length is changed, the tolerance of the aforementioned axial length is &#xb1;0.1L.

Electric motor

In a fluidal machine with an impeller rotating to urge a fluid radially outwardly by a centrifugal force, a vane guiding the fluid discharged from the impeller, a vane member which includes a front end of the vane facing to the impeller so that the fluid discharged from the impeller strikes against the front end and which is prevented from contacting the atmosphere, and a casing surrounding the vane member and contacting the atmosphere, the vane member is discrete from the casing, a vibration propagation between the vane member and the casing is prevented or restrained, and a vibration of a pipe extending from the casing is absorbed.

Fluidal machine

A band pass filter multiplies an input waveform with first trigonometric functions at a plurality of frequencies and then filters the products. Furthermore, with that filtering step, the products are multiplied, or their phase is changed by a predetermined value, and the results are multiplied by the inverse of the trigonometric functions. The sum of this, for all frequencies, generated a filtered output waveform. Where the input waveform has two components, the corresponding outputs can be obtained from the read and imaginary components of the output waveform. In practice the trigonometric functions are produced by sine and cosine components at each frequency. In this way a band pass filter device is formed which is suitable for use in the control system of an apparatus which must be controlled continuously, such as a control system for a rotor.

Band pass filter device and a method of filtering using such a device

Electromagnetic bearing control apparatus

The present invention reduces the resonance amplitude of the rotational frequency-synchronous unbalance vibration of a rotor supported by an electromagnetic bearing. To this end, the invention disposes an X-direction control servo circuit and a Y-direction control servo circuit each of which detects the deviation of the rotor from a desired position in the radial direction thereof and controls the rotor so as to be held at the desired position on the basis of the detection signal, and a tracking filter which is synchronous with the rotational frequency. Outputs from the filter are crossed to supply the Y-direction control servo circuit with the X-directional output and to supply the X-direction control servo circuit with the Y-directional output signal.

Control apparatus for a rotor supported by an electromagnetic bearing

An axial thrust balancing system including a sleeve for balancing an axial thrust applied to a rotary shaft and a bush defining therebetween a clearance having arranged therein at least one pressure chamber for dividing the clearance into a plurality of smaller clearances. The axial division of the clearance reduced the ratio of the axial length of the clearance to the diameter of the sleeve and stabilizes the bearing characteristics of a film of fluid in the clearance, thereby inhibiting the generation of a self-excited vibration of the shaft up to a high rotation velocity.

Axial thrust balancing system

Growing community of inventors

Ushiku, Japan

Michiyuki Takagi