Hitachi, Ltd.

Exedy Corporation

Naohiko Takahashi

Haruo Miura

Yasuo Fukushima

Osami Matsushita

Hideo Nishida

Minoru Hiroshima

Kazuki Takahashi

Mitsuho Yoneyama

Kiyoshi Sakamoto

Hideki Hashimoto

Tsunehiro Endou

Akira Endo

Hiroshi Fujii

Kazuo Takeda

Tsunehiro Endo

Hiromi Kobayashi

Haruo Koharagi

Miyoshi Takahashi

Shinichi Wakui

Kazuyuki Yamaguchi

Tsukasa Taniguchi

Michiyuki Takagi

Yoshiaki Abe

Toyomi Yoshida

Tadashi Kaneki

Kazutoshi Yanagihara

Yohei Magara

Mitsuhiro Narita

Naohumi Sakanashi

Naofumi Sakanashi

Tomoyuki Ishikawa

Takeshi Noguchi

Katsutoshi Seino

Minoru Yoshihara

Ikuhiro Saitoh

Teturo Ohashi

In a centrifugal compressor, for the purpose of preventing the positions of a diaphragm and a head flange in a radial direction from moving with respect to a casing, preventing the unstable vibration of the rotor and enabling an efficient and stable operation even on high-pressure conditions, there is provided a barrel-shaped centrifugal compressor including a casing, a diaphragm located in the casing to define a flow channel, and a head flange attached to the end of the casing by a shear key, wherein in the inner peripheral surface of the casing and the outer peripheral surface of abutment portions of the diaphragm and the head flange in which they are abutted on the inner peripheral surface of the casing, sliding key grooves which are vertical to the surfaces are provided at least two portions in a peripheral direction, and sliding keys are provided in the key grooves.

Barrel-shaped centrifugal compressor

A vibration characteristic measuring apparatus includes a magnetic bearing that generates magnetic force on the rotating body of a multi-stage centrifugal compressor, a displacement sensor that measures the vibration amplitude of the rotating body, a current amplifier that supplies a current to the magnetic bearing, and an excitation controller which outputs an excitation control signal for applying vibration to the rotating body and which measures the response characteristics of the vibration of the rotating body to the excitation control signal. The excitation controller outputs a rotating body control signal obtained by adding a vibration eliminating signal for eliminating unbalance vibration of the rotating body to the excitation control signal when measuring the response characteristics, and the current amplifier supplies a current that generates magnetic force in accordance with the rotating body control signal to the magnetic bearing.

Apparatus and method for measuring vibration characteristics

A turbo compressor, comprising two (2) pieces of rotation shafts, being disposed in parallel with each other, wherein impellers are attached on both ends of one of the rotation shafts, thereby to build up a first-stage compressor and a second-stage compressor, while an impeller on one end of the other rotation shaft, thereby to build up a third-stage compressor. In a lower side of each of the compressors, an intercooler and an after-cooler are disposed in alignment with, for cooling down an operation gas compressed in each stage. The operation gas is guided into the first-stage compressor on a side opposing to a motor, into the second-stage compressor on a side of the motor, and into the third-stage compressor on the side opposing to the motor, in the order thereof.

Turbo compressor

There is provided a control method capable of stably rotating a synchronous motor synchronously with an output frequency even when a phase error between a real rotary axis and a control rotary axis is large. In a phase error operating unit, from the magnitude of the motor current, the magnitude of the motor voltage, the phase difference between the motor current and the motor voltage, and the motor constants, the phase difference between the motor current and the real rotary axis is determined as the first phase difference, and the phase difference between the motor current and the virtual rotary axis is determined as the second phase difference. The difference between the first and second phase differences is defined as the phase error, and the estimation position is so modified as to make the phase error zero.

Position-sensorless controlling method of synchronous motor

In a method of accurately estimating the rotor position of a synchronous motor having saliency from observable quantities, a control system for adjusting an output frequency of an inverter on the basis of a value of axis shift of the synchronous motor to operate the motor synchronously with the output frequency is provided with an induced voltage estimating/axis shift operating unit. Currents resulting from conversion of detection currents on a control axis, voltage commands to be inputted to an inverse converter and a speed command are inputted to the operating unit to estimate an induced voltage of the motor and determine the axis shift from a phase of the estimated induced voltage. By using an electrical constant Lq of inductance, a voltage drop across the inductance is determined by the product of a motor speed command and magnitude of motor current. The voltage drop is a virtual quantity that does not depend on the motor rotor position. A vector of the virtual quantity is so introduced as not to change a phase of the original induced voltage.

Method of estimating a rotor position of synchronous motor, method of controlling synchronous motor with no position sensor and a controller of synchronous motor

In an ultra-permanent-magnet-type electric rotating machine including a stator in which a winding of armatures is wound in each of a plurality of slots of a stator core, and a rotor having permanent magnets respectively inserted into permanent-magnet-inserting holes in a magnetic steel sheet ring provided at an outer periphery of a conductive and magnetic shaft, the thickness of the stator core is 0.1 to 0.2 mm, and the magnetic steel sheet ring is made of a high-tensile-strength magnetic steel sheet had tensile strength of 80 kg/mm or more.

Permanent-magnet-type electric rotating machine and air compressor and generator using the same

A clutch disk assembly (,) is provided between an input shaft and an output shaft to selectively transmit rotation therebetween. The clutch disk assembly (,) is provided with a dampening mechanism (,) to provide smooth transition during engagement and disengagement of the clutch disk assembly. The dampening mechanism (,) has a more durable second retaining plate (,) with a rectangular window portion for transmitting torque. This second retaining plate (,) has a second receptacle (,) to support a first spring (,). The second retaining plate (,) includes a disk-like plate main body. The second receptacle (,) is formed from that plate main body. The second receptacle (,) projects in an axial direction from the plate main body. The second receptacle (,) includes an axially supporting part (,) and a circular supporting part (,). The axially supporting part (,) supports an axially outside part of the first spring (,) and continues in a radial direction. The circular supporting part (,) supports both end parts of the first spring (,), and is formed on both circular ends of the axially supporting part (,). A second hole (,) is formed at both corners of an inner circumferential side of the axially supporting part (,). The second holes (,) are elongated holes that extend in a radial direction.

Dampening disk assembly with spring retaining plate

A low pressure-side first-stage compressor impeller and a high pressure-side second-stage compressor impeller are mounted respectively on opposite ends of a rotation shaft. A rotor of an electric motor for driving the two impellers is formed at a central portion of the rotation shaft. A stator of the motor is held by a motor casing. The motor casing, a first-stage compressor casing, which cooperates with the first-stage compressor impeller to form a first-stage compressor, and a second-stage compressor casing, which cooperates with the second-stage compressor impeller to form a second-stage compressor, are cast into an integral construction. This integral casing is further formed integrally with an intermediate cooler, disposed downstream of the first-stage compressor, and a discharge cooler disposed downstream of the second-stage compressor. The intermediate cooler and the discharge cooler are disposed below the motor casing in generally parallel relation to the rotation shaft, and the main portions of the two-stage centrifugal compressor are combined into a compact, generally rectangular parallelepiped configuration.

Two-stage centrifugal compressor

A spline hub 6 is formed with a cylindrical boss (11) configured for engagement with a shaft extending from, for instance, a transmission. Axial spline grooves and circumferential grease grooves (14) are formed on the inner peripheral surface of the boss (11). A first axial end surface (14) of the grease groove (14) is tapered.

Spline hub and method of manufacturing the spline hub

In a rotating machine with employment of a sensor-less DC brushless motor, a terminal voltage of a motor is corrected in a phase corrector by using a motor phase current signal. At this time, the terminal voltage is processed in an integrator and a comparator so as to be converted into an ON/OFF signal having a duty ratio of 1:1. Then, a rotation signal is produced based on an induced voltage which is generated by rotating a permanent magnet rotor, so that a rotation sensor is no longer required. On the other hand, an output derived from the phase corrector is entered as a 1-pulse/1-rotation output signal into a PLL circuit. The PLL circuit contains a phase comparator, a low-pass filter, an oscillator, and a counter. The PLL circuit frequency-divides the 1-pulse/1-rotation output signal. The sine wave data are stored into a ROM with respect to each of the frequency-divided signal positions. The unbalance vibrations of the magnetic bearing are controlled every frequency-divided signal.

Magnetic bearing, rotating machine mounting the same, and method for

A manufacturing method of a rotor for a permanent magnet-excited, high-speed electric rotary machine according to the present invention comprises, covering an outer circumferential surface of at least one permanent magnet by a fiber-reinforced plastic protection cover with prestress compressing in radial direction; inserting a steel sleeve into the at least one permanent magnet to form a permanent magnet assembly; preparing at least one permanent magnet assembly; inserting a rotor shaft into the steel sleeve while applying hydraulic pressure to an inner circumferential surface of the steel sleeve of the prepared at least one permanent magnet assembly to expand the steel sleeve; and then removing the hydraulic pressure to tight fit the at least one permanent magnet assembly onto the rotor shaft.

Rotor for permanent magnet excited, high-speed electric rotary machine,

A multi-stage compressor having at least two compressor stages comprises an inter-cooler provided between the stages for cooling a gas being discharged from a compressor in the preceding stage. The compressor stages are driven by a common electric motor, of which a rotating shaft is supported by magnetic bearings. A part of the gas cooled by the inter-cooler and a part of the work gas discharged from a bleed valve provided down-stream of a rear stage of the compressor are selectively introduced into the electric motor or the magnetic bearings. Thus, at the time of load operation the gas discharged from the inter-cooler is introduced into the motor or the magnetic bearings to cool them, and at the time of non-load operation the gas discharged from the bleed valve is introduced into the motor or the magnetic bearings to cool them. It is possible to ensure a flow rate of gas required for cooling the motor during non-load operation with economy during load operation.

Multi-stage compressor having first and second passages for cooling a

Active magnetic bearings supporting a rotor operated at high speeds is controlled by a controller. Tracking filters provided in the controller pick up forward vibration components in synchronism with the rotational speeds from the displacement signals of the rotor, and a mode separating circuit provided in a mode gain controller takes out displacements of the 3rd and 4th modes. Then, a gain controller provided in the mode gain controller determines suitable gains for the separated displacement signals. A mode synthesizing circuit provided in the mode gain controller synthesizes a controlled variable for each of the bearings from the control signals that are processed for the respective modes. By adding the control variable to the respective bearings, the vibration amplitude is suppressed in critical speed zones of high orders, and the rotor is stably operated up to a high-speed range.

High-speed rotor and controller for controlling magnetic bearings used

A magnetic bearing is provided with a simulating circuit for estimating a displacement of a rotor on the basis of a force which is exerted on the rotor. An output of the simulating circuit is compared with an actual displacement signal. A delay circuit and a subtracter are provided to subtract a run-out, which was estimated one period before the rotation of the rotor, from the displacement signal. A displacement signal from which the run-out component was eliminated is set to a new displacement signal. A signal which is obtained by adding an estimated run-out of one period before, namely, an output of the delay circuit to the run-out which was estimated by comparing the output of the simulating circuit with the new displacement signal is newly inputted to the delay circuit. Due to this, the run-out component is eliminated from the displacement signal of the magnetic bearing, the load on power amplifiers for driving the electromagnets is reduced, there is a surplus for a saturation which is caused in a high frequency band, the reliability of the control system is improved, and deterioration of positional accuracy due to the run-out is prevented.

Magnetic bearing apparatus and rotating machine having such an apparatus

A controller of magnetic bearing controls the rotor speed with a reduced drive current while suppressing the rotor vibration. The controller implements the ABS control, N-cross control, N-straight control and FF control in proper combination in addition to the basic PID control. A computer in the controller determines the activation of each control in accordance with a predetermined table of control plan in response to the detected rotor speed.

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Ibaraki, Japan

Naohiko Takahashi