摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
In a fluid machine such as multistage centrifugal compressor, the pressure of a working fluid is raised with the rotation of a impeller. A shaft sealing device is mounted at the end of the rotary shaft in order to prevent the working gas of the raised pressure from leaking out of the fluid machine and then polluting the surroundings. In a case where the fluid machine operates to rotate at high speed, a labyrinth sealing device is employed for the purpose of reducing a frictional loss in the shaft sealing device. The labyrinth sealing device includes a plurality of stages of labyrinth fins which are formed on a casing or the rotary shaft, and a layer of abradable coating to-be-bitten which is formed in the surface part of the rotary shaft or the casing opposing to the labyrinth fins. The clearances between the labyrinth fins and the rotary shaft or the casing are made narrower on the low-pressure side of the labyrinth sealing device than on the high-pressure side thereof. Thus, the fluid machine is run with the minimum clearance. Moreover, even when the coating layer has been lost in contacting the labyrinth fin or by peeling off, the labyrinth fin on the low-pressure side acts as a labyrinth seal.
摘要:
A heat exchanger used in a screw air compressor has a low temperature chamber through which low temperature fluid flows and a high temperature chamber through which high temperature fluid flows. The low temperature chamber and the high temperature chamber are separated by a partition plate. The high temperature chambers and the low temperature chambers are alternately arranged in layers, so that the low temperature chambers are disposed at both ends in a layered direction. Additionally, the flowing direction of the low temperature fluid in the low temperature chambers and the flowing direction of the high temperature fluid in the high temperature chambers are substantially orthogonal to each other.
摘要:
A heat exchanger used in a screw air compressor has a low temperature chamber through which low temperature fluid flows and a high temperature chamber through which high temperature fluid flows. The low temperature chamber and the high temperature chamber are separated by a partition plate. The high temperature chambers and the low temperature chambers are alternately arranged in layers, so that the low temperature chambers are disposed at both ends in a layered direction. Additionally, the flowing direction of the low temperature fluid in the low temperature chambers and the flowing direction of the high temperature fluid in the high temperature chambers are substantially orthogonal to each other.
摘要:
A package-type screw compressor includes a low-pressure stage state compressor and a high-pressure stage compressor. Motive power is transmitted from an electric motor to the two compressors via a speed increaser. The discharge gas, compressed and heated to a high temperature by the low-pressure stage compressor, is cooled by an intercooler. The discharge gas, compressed and heated to a high temperature by the high-pressure stage compressor, is cooled by an aftercooler. A casing of the intercooler and that of the aftercooler are formed integrally with a speed increaser casing, reducing the number of component parts. A cooler portion, formed by the intercooler and the aftercooler, is spaced from the speed increaser casing, thereby preventing heat, produced by the compressed air, from being transmitted to the speed increaser casing.
摘要:
A package-type screw compressor includes a low-pressure stage state compressor and a high-pressure stage compressor. Motive power is transmitted from an electric motor to the two compressors via a speed increaser. The discharge gas, compressed and heated to a high temperature by the low-pressure stage compressor, is cooled by an intercooler. The discharge gas, compressed and heated to a high temperature by the high-pressure stage compressor, is cooled by an aftercooler. A casing of the intercooler and that of the aftercooler are formed integrally with a speed increaser casing, reducing the number of component parts. A cooler portion, formed by the intercooler and the aftercooler, is spaced from the speed increaser casing, thereby preventing heat, produced by the compressed air, from being transmitted to the speed increaser casing.
摘要:
In a fluid machine such as multistage centrifugal compressor, the pressure of a working fluid is raised with the rotation of a impeller. A shaft sealing device is mounted at the end of the rotary shaft in order to prevent the working gas of the raised pressure from leaking out of the fluid machine and then polluting the surroundings. In a case where the fluid machine operates to rotate at high speed, a labyrinth sealing device is employed for the purpose of reducing a frictional loss in the shaft sealing device. The labyrinth sealing device includes a plurality of stages of labyrinth fins which are formed on a casing or the rotary shaft, and a layer of abradable coating to-be-bitten which is formed in the surface part of the rotary shaft or the casing opposing to the labyrinth fins. The clearances between the labyrinth fins and the rotary shaft or the casing are made narrower on the low-pressure side of the labyrinth sealing device than on the high-pressure side thereof. Thus, the fluid machine is run with the minimum clearance. Moreover, even when the coating layer has been lost in touch with the labyrinth fin or by peeling off, the labyrinth fin on the low-pressure side acts as a labyrinth seal.