Patents
Literature
Patsnap Eureka AI that helps you search prior art, draft patents, and assess FTO risks, powered by patent and scientific literature data.

215 results about "Rotational frequency" patented technology

Method for diagnosing rotor rub-impact in rotating machinery based on vibration signal deconstruction and frequency modulation characteristic anti-noise enhancement

A method for diagnosing rotor rub-impact in a rotating machinery based on vibration signal deconstruction and frequency modulation characteristic anti-noise enhancement, including: converting, based on two-stage integration transformation and high-pass filtering, vibratory acceleration signals from a rotating machinery device into vibratory displacement signals; performing targeted extraction on a rotating frequency component therein based on an improved variational mode decomposition method; calculating and estimating instantaneous fluctuation characteristics of a fundamental frequency of the extracted rotating frequency component using a quadrature-derivative-based normalized Hilbert transform to obtain an instantaneous frequency; inputting a calculated instantaneous frequency sequence into an optimum stochastic resonance system for anti-noise enhancement of intrawave frequency modulation characteristics; and processing FFT on an instantaneous frequency of intrawave frequency modulation characteristics after anti-noise enhancement, and diagnosing and identifying a rotor rub-impact fault of the rotating machinery based on a distribution characteristic of harmonic amplitudes related to a rotor rotating frequency.
Owner:ZHEJIANG UNIV

Friction stir spot welder and friction stir spot welding method

A friction stir spot welder includes: a pin; a shoulder; a rotary driver; a tool driver; and circuitry that performs an operation of driving the rotary driver and the tool driver such that the pin and the shoulder press a workpiece by a first pressing force while rotating at a first rotational frequency, and after the operation, performs an operation of driving the rotary driver and the tool driver such that a tip of the shoulder in a rotating state is pressed in to a first position. The first position is a position corresponding to 46% or more of a thickness of the workpiece from a front surface of the workpiece. A press-in speed of the shoulder until the shoulder reaches the first position is a constant speed.
Owner:KAWASAKI JUKOGYO KK

Alternating current excitation system self-starting control method and system

The invention discloses an AC excitation system self-starting control method and system, and the method comprises the steps: obtaining a rotor current rotation frequency and an actual rotor rotation frequency, and generating a slip frequency; the slip frequency is compared with a preset dynamic threshold value, and the rotating speed given value is dynamically adjusted; inquiring a preset multi-stage sectional type current control curve according to the actual rotor rotation frequency, and outputting a d-axis current given value; pI adjustment is carried out based on the slip frequency to generate a q-axis current given value, and corresponding preset current threshold limit is applied according to the frequency band where the actual rotor rotation frequency is located; performing independent parameter configuration on the magnetic flux current control loop and the torque current control loop by adopting a non-coupling parameter setting algorithm; and in the unit starting process, under the condition that the stable starting constraint condition is met, an optimal starting parameter combination is generated. According to the invention, by dynamically adjusting the rotating speed given value and controlling the current in a segmented manner, the stable self-starting of the alternating current excitation system is realized, and the reliability and efficiency of the starting process are improved.
Owner:GUANGZHOU QINGTIAN INDAL +1

Signal processing device, diagnostic system, and signal processing method

Provided are a signal processing device, a diagnostic system, and a signal processing method with which it is possible to improve the accuracy of a determination value for determining a lubrication state in a rolling device. A signal processing device (3), which calculates a determination value for determining a lubrication state in a rolling device on the basis of a measurement signal acquired by a sensor (2), is provided with: a first processing unit (321) which converts the measurement signal into a time-domain signal by performing band limitation and envelope processing on the measurement signal; a second processing unit (322) that converts the time-domain signal into a first frequency-domain signal; a third processing unit (323) that converts the logarithmic spectrum of the first frequency domain signal into a first inverse frequency domain signal; a fourth processing unit (324) that generates a second inverted-frequency-domain signal in which the high-order cepstrum domain, which includes the rotation frequency of the scrolling device, of the first inverted-frequency-domain signal is set to a prescribed value; a fifth processing unit (325) that converts the second inverted frequency domain signal into a second frequency domain signal; and a determination value calculation processing unit (33) that calculates a determination value on the basis of the second frequency domain signal.
Owner:NSK LTD

Air conditioning system and air conditioning method for building

To provide an air conditioning system for a building capable of improving temperature controllability and comfort in a room.SOLUTION: The present invention relates to an air conditioning system 1 for a building. The air conditioning system 1 includes an air conditioner 11, a duct 12, a fan 13, a room temperature sensor 14 and a control device 15. The control device 15 includes: a target temperature input section; a room temperature acquisition section; a normal operation section that operates the fan 13; a first determination section that determines whether or not a difference between a room temperature and a target temperature is a predetermined threshold value or larger; a second determination section that determines whether or not the fan 13 is being operated at maximum air quantity notch when the determination made by the first determination section is affirmative; a third determination section that determines whether or not rotational frequency of the fan 13 is smaller than the maximum rotational frequency when the determination made by the second determination section is affirmative; a fourth determination section that determines whether or not a stronger air conditioning action is required on the basis of a change of the difference between the room temperature and the target temperature when the determination made by the third determination section is affirmative; and a rapid operation section that further increases the rotational frequency of the fan 13 within a range up to the maximum rotational frequency when the determination made by the fourth determination section is affirmative.SELECTED DRAWING: Figure 1
Owner:PANASONIC HOMES CO LTD

Bearing fault acoustic detection method and system based on fractional harmonic phase-locked amplification

ActiveCN120429767AMachine part testingVibration amplitudeHarmonic phase
The invention discloses a bearing fault acoustic detection method and system based on fractional harmonic phase-locked amplification, and the method comprises the steps: obtaining an acoustic signal of a target motor, measuring the shaft rotation frequency of a motor shaft in real time, synchronizing the shaft rotation frequency to a fractional phase-locked loop, and carrying out the calculation of a bearing fault characteristic frequency according to the geometric parameters of a bearing, the bearing fault characteristic frequency is a non-integer multiple of the shaft rotation frequency, generating a reference signal synchronous with the bearing fault characteristic frequency through a fractional phase-locked loop, and performing phase sensitive detection on the obtained acoustic signal and the generated reference signal by using a phase-locked amplifier, specifically, performing orthogonal demodulation on the acoustic signal and the reference signal, and performing phase sensitive detection on the obtained acoustic signal and the reference signal. The method comprises the following steps: generating an in-phase component and an orthogonal component, extracting a direct-current component through low-pass filtering, calculating to obtain a vibration amplitude and phase information corresponding to a bearing fault characteristic frequency, and judging the type and severity of a bearing fault according to the comparison between the vibration amplitude and a preset baseline, the harmonic consistency and the phase stability.
Owner:ZHEJIANG GONGSHANG UNIVERSITY

Actuator mechanism for an item of household equipment

Embodiments of the invention provide a door opener for an electrical appliance of household equipment. The door opener comprises an electric motor and a pusher drivable by means of the electric motor for pressing co-operation with the door of the electrical appliance. A power transmission mechanism is provided between the electric motor and the pusher, which is capable of ensuring a variable effective velocity of the pusher at the same rotational frequency of the electric motor. Certain embodiments provide for a multi-stage rack and pinion gear for this purpose, which is formed by a gear rim and a toothed rack, which can transmit the driving force of the electric motor to the pusher via various gear pairings that can be brought alternately into meshing engagement with one another.
Owner:EMZ HANAUER GMBH & CO KGAA

Fault feature identification method and system for rotating part in tachometer-free scene

The invention belongs to the field of aero-engine test and fault diagnosis, relates to an engine rotating part fault positioning technology, and provides a rotating part fault feature recognition method and system in a tachometer-free scene, and the method comprises the steps: obtaining a vibration signal and a theoretical fault feature order of a rotating part; obtaining an instantaneous rotating frequency signal of the rotating part through the constructed non-convex linear transformation regular term sparse representation model; carrying out iterative solution through the constructed sparse representation model to obtain a fault characteristic signal of the rotating part; obtaining an order envelope spectrum according to the instantaneous frequency conversion signal and the fault characteristic signal; and performing health assessment and fault identification on the rotating part according to the order envelope spectrum and the theoretical fault feature order. The method can solve the problem that the variable-speed fault of the rotating shaft part of the aero-engine cannot be recognized in a non-rotating-speed scene. Through the implementation of the method, the fault of the rotating shaft part of the aero-engine is effectively identified, and technical support is provided for troubleshooting in an aero-engine test.
Owner:AECC SICHUAN GAS TURBINE RES INST

Finishing method and finishing device for finish machining of rolling element raceways

The invention relates to a finishing method for finish machining of a workpiece having at least one raceway for rolling elements that extends around a workpiece axis, the method comprising the following steps: providing a finishing tool which has an abrasive working surface; applying the finishing tool to a workpiece holder, generating spinning of the workpiece about a raceway axis at a rotational frequency; generating an oscillating movement of the tool holder, which is superimposed on the spinning of the workpiece and oscillates at an oscillating frequency; and pressing the finishing tool onto the workpiece surface in a pressing direction with a pressing force so that the abrasive working surface acts on the workpiece in the region of the raceway. The finishing method is characterised by continuous detection of a force signal, which is caused by the pressing force, within a detection time period which partly or completely overlaps a machining time period of the finish machining, and by time-resolved evaluation of the force signal in order to determine at least one geometry parameter which represents (i) a workpiece geometry in the region of the machined raceway and / or (ii) a geometric relationship between the workpiece geometry in the region of the machined raceway and a position of an oscillating apparatus.
Owner:NAGEL TECHNOLOGIES GMBH

Data extraction device and abnormality monitoring device

In a data extraction device (30) of the present invention, an envelope spectrum that is an envelope-processed wave spectrum is used as data for abnormality determination. The data for abnormality determination is less affected by noise as compared with the related art that directly uses a vibration wave spectrum, and the accuracy of abnormality determination is enhanced. The envelope spectrum in a limited frequency range including a frequency of a specific wave in the envelope-processed waves is extracted as the data for abnormality determination. Data not used for the abnormality determination is eliminated, and the abnormality determination is facilitated. The frequency of the specific wave even when changing with a change in the rotational frequency of a bearing (94) is calculated from the rotational frequency of the bearing (94) to determine the limited frequency range. The abnormality determination can be easily performed without being affected by the change in the rotational frequency of the bearing (94).
Owner:ASAHI SEIKI INDUSTRIES

Technique for controlling brushless dc motor of electric work machine

An electric work machine in one aspect of the present disclosure includes an output shaft, a brushless DC motor, a first positive-side conduction path, a first negative-side conduction path, a first switch device, a manual switch, a rotation sensor, and a controller. The first switch device is on the first positive-side conduction path or the first negative-side conduction path. The controller controls a magnitude of a conduction angle based on an actual rotational frequency and a target rotational frequency of the brushless DC motor.
Owner:MAKITA CORP

Program, information processing method, and information processing device

To provide a program or the like allowing a player to grasp a rate of rotation at optional timing in a game of a game machine.SOLUTION: A computer receives input of a rotational frequency showing the number of lotteries from the most recent winning at a point of time when a game machine wins a lottery during a game of the game machine having a start pocket in which a predetermined lottery is held when game balls enter it according to a program. Then, the computer calculates a rate of rotation showing a rotational frequency per a predetermined amount on the basis of an inputted rotational frequency, and an investment amount until an analysis instruction is received when receiving the analysis instruction of a game situation.SELECTED DRAWING: Figure 3
Owner:QHRON JOINT CO

Bearingless motor system, compressor and refrigeration device

A bearingless motor (110) includes a rotor (111) disposed on a rotating shaft (101), and a stator (112) having a shaft support winding (113) and a motor winding (115). The first inverter (114) supplies power to the shaft support winding (113) and generates a shaft support force that supports the rotating shaft (101) in a non-contact manner. The second inverter (116) supplies power to the motor winding (115), thereby generating a rotational torque on the rotating shaft (101). The control unit (200) causes one or both of the first inverter (114) and the second inverter (116) to output a voltage or a current in which a harmonic wave obtained by multiplying the rotational frequency of the bearingless motor (110) by a natural number of 2 or more is superimposed so as to reduce fluctuations in the shaft supporting force.
Owner:DAIKIN INDUSTRIES LTD

Lawn mower

A lawn mower includes: a cutting blade motor that drives a cutting blade; a mode selector that selects one of modes including a normal lawn mowing mode and a grass removal mode in which grass accumulated at the cutting blade is brushed away; and processing circuitry configured to control the cutting blade motor in the mode selected by the mode selector. In the normal lawn mowing mode, the cutting blade motor is controlled so as to rotate in a normal rotation direction at a predetermined rotational frequency or with a predetermined torque. In the grass removal mode, the cutting blade motor is controlled such that the rotational frequency or torque of the cutting blade motor changes more significantly than the rotational frequency or torque of the cutting blade motor in the normal lawn mowing mode, or the cutting blade motor rotates in a reverse rotation direction.
Owner:KAWASAKI MOTORS LTD

Novel method for synthesizing trifluoromethyl heteroaromatic hydrocarbon in rotating magnetic field

The invention belongs to the technical field of organic chemical synthesis, and particularly relates to a novel method for synthesizing trifluoromethyl heteroaromatic hydrocarbon. The invention provides a novel method for synthesizing a trifluoromethyl heteroaromatic compound, the reaction system is mild, the substrate application range is wide, and the functional group compatibility is good. Specifically, in a rotating magnetic field, a metal conductor cuts magnetic induction lines to generate electron transfer, so that trifluoromethyl sulfosalt is reduced to generate trifluoromethyl free radicals, and the trifluoromethyl free radicals react with heteroaromatic hydrocarbon to synthesize trifluoromethyl heteroaromatic hydrocarbon. The method for synthesizing the trifluoromethyl heteroaromatic hydrocarbon comprises the following steps that firstly, heteroaromatic hydrocarbon, trifluoromethyl sulfosalt, a solvent and a metal rod are placed in a reaction tube and react in a multi-energy field coupling device, the magnetic field intensity (B) is set to be 0.01-3.00 T, the rotation frequency is set to be 5-50 Hz, the reaction time is set to be 1-24 h, finally, the trifluoromethyl heteroaromatic hydrocarbon is prepared, and the general formula of the trifluoromethyl heteroaromatic hydrocarbon is shown in the specification.
Owner:SHANDONG UNIV OF TECH +1

Method of measuring tire wear using vehicle speed

A method for determining a tread remainder on a tire is provided in which first speed data and second speed data of a vehicle are obtained, the second speed data being derived in part from a measurement of a rotational frequency of the tire. The first velocity data is filtered to obtain extracted filtered first velocity data that exceeds a first predefined velocity limit, and the second velocity data is filtered such that filtered second velocity data that exceeds a second predefined velocity limit is extracted. A ratio is calculated using the filtered first velocity data and the filtered second velocity data. Further, the method includes comparing the ratio to a tire model correlating the ratio to a tread remainder in order to determine the tread remainder on the tire.
Owner:MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)

Diagnostic apparatus, moving body, computer readable storage medium, and diagnostic method

A diagnostic apparatus, for diagnosing a state of equipment including a rotating component that rotates by force transmitted from a rotating shaft, includes: a vibration information acquisition section for acquiring vibration information including waveform information of vibration of the rotating component; an analysis section for decomposing a vibration waveform into frequency components and outputting values of vibration levels for each frequency component; and a determination section for determining a presence or absence of an abnormality in at least one of the rotating shaft and the rotating component. For a range from a first frequency, which is smaller than a rotation frequency of the rotating shaft, to the rotation frequency, the determination section compares, for each frequency component, a value of a vibration level with a normal value thereof, and determine a presence or absence of an abnormality in at least one of the rotating shaft and the rotating component.
Owner:HONDA MOTOR CO LTD

Chip hotspot heat dissipation system based on micro robot

The application provides a chip hotspot heat dissipation system based on a micro robot, which comprises a magnetic field control device for generating a uniform magnetic field; a chip is placed in the uniform magnetic field; a heat dissipation channel is arranged on the surface of the chip, and a cooling medium for conducting convective heat exchange on a hotspot is circulated in the heat dissipation channel; a robot is made of a magnetic material and is placed in the cooling medium; and a processor is used for controlling the magnetic field control device to generate a magnetic field at a first target rotating frequency, so as to drive the robot to run in the cooling medium to a region where the hotspot of the chip is located; and the processor is also used for controlling the magnetic field control device to generate a magnetic field at a second target rotating frequency, so as to drive the robot to rotate in place in the region where the hotspot of the chip is located, so as to dissipate heat of the hotspot of the chip. The system provided by the application effectively solves the problem that the prior art is difficult to accurately match the dynamic migration characteristics of the hotspot; and the heat dissipation efficiency of the hotspot of the chip is improved.
Owner:XI'AN UNIVERSITY OF ARCHITECTURE AND TECHNOLOGY +1

Method and device for testing dynamic response to inertial sensor based on rotating mass source

The invention belongs to the technical field of inertial sensor testing, and particularly discloses a method and a device for testing dynamic response to an inertial sensor based on a rotary mass source, the device comprises a mounting platform, a rotary table and a signal processing module, two same mass sources are fixed on the rotary table, and the two mass sources are symmetrically arranged relative to the center of the rotary table; the mounting platform is used for bearing an inertial sensor to be detected and rotating according to a specific rotating frequency to generate a universal gravitation acceleration signal which changes periodically, and the frequency is two times of the rotating frequency of the turntable; and the signal processing module is used for acquiring a dynamic response test result of the inertial sensor to be tested based on the actually measured acceleration signal and the theoretical acceleration signal. According to the method and the device, the dynamic response of the inertial sensor can be accurately tested for the high-precision inertial sensor with the resolution reaching the ng magnitude level.
Owner:HUAZHONG UNIV OF SCI & TECH

Method and device for determining hydraulic damping of underwater rotating disc

The invention provides a method and device for determining hydraulic damping of an underwater rotating disc, and relates to the technical field of hydrodynamics, the method comprises the following steps: obtaining a vertical displacement vibration signal of the rotating disc in a composite mode through vibration mode measurement; performing iterative filtering on the vertical displacement vibration signal to obtain a target signal of the rotating disc in a pitch circle mode; fitting a vibration response function of the rotating disc based on the target signal; based on the vibration response function, establishing a frequency response function of the rotating disc; determining the inherent frequency of the rotating disc based on the frequency response function; based on the rotating frequency of the rotating disc, performing dimensionless processing on the inherent frequency to obtain the falling frequency of the rotating disc; and based on the drop frequency, performing linear fitting regression on the hydraulic damping of the rotating disc to obtain a relational expression between the hydraulic damping and the drop frequency. According to the method for determining the hydraulic damping of the underwater rotating disc, the hydraulic damping of the rotating disc is accurately measured.
Owner:CHINA AGRI UNIV

Adaptive frequency band division bearing fault diagnosis method and device based on variable iteration

The invention provides an adaptive frequency band division bearing fault diagnosis method and device based on variable iteration, and belongs to the technical field of bearing fault diagnosis, and the method comprises the steps: obtaining a vibration signal and a rotation frequency of a bearing fault, and determining an energy spectrum corresponding to the vibration signal; determining a target energy spectrum band; determining an adaptive frequency iteration step length based on the frequency bandwidth of the target energy spectrum band corresponding to the maximum energy amplitude; based on the initial bandwidth, the rotation frequency and a preset frequency band demodulation hierarchy number, determining the hierarchy window length of each hierarchy demodulation window; based on the window length of each layer, performing iterative search on each frequency band demodulation layer by adopting an adaptive frequency iterative step length, and determining a harmonic significant index corresponding to each frequency band demodulation layer; determining an adaptive division frequency band based on the harmonic significance index corresponding to each frequency band demodulation level; envelope demodulation is carried out based on adaptive frequency band division, the fault type of the bearing is determined, and the bearing fault diagnosis speed and positioning precision are improved.
Owner:SOUTHWEST JIAOTONG UNIV

Coupling device for measuring offset and rotational frequency, drive train and method for measuring an offset or rotational frequency in a coupling

A coupling device (100) for measuring misalignment and rotational frequency for coupling a first shaft (210) with a second shaft (220) comprises a hub component (110) with a hub configured to connect to the first shaft (210). The coupling device (100) further comprises a transmission device (120) configured to transmit torque between the first shaft (210) and the second shaft (220) and to compensate for any misalignment between them. The coupling device (100) further comprises a connecting element (130) configured to connect the transmission device (120) to the hub component (110).The connecting element (130) includes a measuring device inside the connecting element (130), and the measuring device is configured to measure a load on the connecting element (130) when the rotational movement is transmitted between the first shaft (210) and the second shaft (220) in order to determine the offset or rotational frequency of the first shaft (210) and the second shaft (220).
Owner:TECH UNIV DARMSTADT

Abnormality detection device, air conditioner, and abnormality detection method

The purpose of an abnormality detection device (1) according to the present disclosure is to detect an incipient turn-to-turn short. The abnormality detection device (1) is characterized by comprising: a frequency analysis unit (12) that performs frequency analysis on physical-quantity data of a rotating electrical machine (2); a mechanical-angle rotational frequency harmonic component extraction unit (13) that extracts a specific-order harmonic component of a mechanical-angle rotational frequency from among components having been subjected to the frequency analysis; and an abnormality determination unit (15) that compares the extracted specific-order harmonic component with a threshold value (I threshold) and that determines the presence or absence of a turn-to-turn short circuit in the rotating electrical machine (2).
Owner:MITSUBISHI ELECTRIC CORP

Compressor and control method thereof

A compressor (1) is provided with: a compressor main body (2) that sucks and compresses a gas to be compressed; heat exchangers (11, 12) that cool a cooling object while circulating the cooling object inside; a fan (14) that is driven by a fan motor (13) and blows cooling gas against the heat exchangers (11, 12) to exhaust heat therefrom; a temperature sensor (21) that detects a temperature of the cooling gas, i.e., a cooling gas initial temperature, which has not yet been subjected to heat exhaust by the heat exchangers (11, 12); and a control unit (5) that can set an upper limit frequency as an upper limit of a rotation frequency of the fan motor (13). The control unit (5) sets the upper limit frequency so that, at each cooling gas initial temperature detected by the temperature sensor (21), the upper limit frequency is a rotation frequency at which a current supplied to the fan motor (13) becomes a permissible current value or less.
Owner:KOSCO COMPRESSOR CO LTD

Air conditioner

An air conditioner according to an embodiment of the present invention includes: a refrigerant circuit including a compressor, an outdoor heat exchanger, an indoor heat exchanger, and a pressure reducer that is disposed between the outdoor heat exchanger and the indoor heat exchanger; an outdoor fan that blows the air to the outdoor heat exchanger; an indoor fan that blows the air to the indoor heat exchanger; and a control device that sets an upper limit value of a rotational frequency of the outdoor fan in accordance with a rotational frequency of the indoor fan.
Owner:FUJITSU GENERAL LTD

Abnormality detection system for hydraulic rotary machine

PCT designated stageWO2025187111A8Pump testingPump controlFrequency spectrumPressure amplitude
An abnormality detection system (7) for a hydraulic rotary machine (1) according to an embodiment includes: a pressure gauge (71) that measures pressure relating to the hydraulic rotary machine (1); and a processing circuit (73). The processing circuit (73) performs frequency analysis of a pressure waveform, which is the measurement result of the pressure gauge (71), a plurality of times to create a frequency spectrum, records the pressure amplitude of a specific order component that is an integral multiple of the rotation frequency in the frequency spectrum, calculates the occurrence frequency of each value of the recorded pressure amplitude, and determines the presence or absence of an abnormality in the hydraulic rotary machine (1) on the basis of a temporal change in a frequency curve on a graph relating to the pressure amplitude and the occurrence frequency.
Owner:KAWASAKI JUKOGYO KK

Method for welding coated steel plates

The present invention provides a method for welding coated steel sheets, preferably for welding aluminum-silicon-based metal-coated steel sheets, comprising the following steps: providing a structure with two laser beams, said laser beams acting on the molten pool to be formed, at least one laser beam rotating about a rotation axis so that said laser beams move relative to each other, said laser beams being guided along the welding axis, in order to mix the molten pool, observing a defined stirring effect in conjunction with a defined welding speed, the following conditions applying to the stirring effect: wherein f rot is the rotation frequency, v w For the welding speed, the following conditions apply: when welding the coated steel sheets, auxiliary materials, in particular welding filler wires, are used. The auxiliary materials, in particular welding filler wires, are used.
Owner:WÖSTALPINE AUTOMOTIVE COMPONENTS LINZ GMBH & CO CAGE

Motor-driven compressor

Motor-driven compressor (10), with an electric motor (16) including a rotor (51), a housing (11) including a suction port (11a) which sucks in a fluid, a compression unit (15) driven by the electric motor (16), the compression unit (15) compressing an inlet fluid, which is the fluid sucked in through the suction port (11a), and discharging a compressed fluid, which is the compressed inlet fluid, a drive circuit (55) which drives the electric motor (16), and a control device (60) which controls the drive circuit (55) to control rotation of the rotor (51), wherein the compression unit (15) has a fixed roller (31) attached to the housing (11), a movable roller (32) engaged with the fixed roller (31) and adapted to orbit the fixed roller (31), and a compression chamber (33) defined by the fixed roller (31) and the movable roller (32), wherein, when the rotor (51) rotates in a predetermined forward direction, the movable roller (32) orbits in the forward direction, and the compression unit (15) thereby compresses the inlet fluid sucked into the compression chamber (33), wherein the motor-driven compressor (10) further comprises an injection port (43) which sucks an intermediate pressure fluid into the compression chamber (33), the intermediate pressure fluid having a pressure higher than that of the inlet fluid and lower than that of the compressed fluid, wherein the control device (60) comprises a deceleration control device that performs a deceleration control that decelerates the rotor (51) during a first period in response to rotating the rotor (51) in a direction opposite to the forward direction, and a continuation control means which performs a continuation control which continues the rotation of the rotor (51) during a second period of time which is longer than the first period of time after the deceleration control is performed, and wherein a fluctuation difference of a rotation frequency of the rotor (51) during the continuation control is less than a deceleration rotation frequency difference, which is a difference between a rotation frequency of the rotor (51) when the deceleration control is started and a rotation frequency of the rotor (51) when the deceleration control is ended.
Owner:TOYOTA INDUSTRIES CORP

Vibration suppression method, device and system for rotor in magnetic bearing system

The present invention relates to a method, device, and system for suppressing rotor vibration in a magnetic bearing system, belonging to the field of magnetic bearing control technology. The method comprises: predicting a second displacement signal of the rotor at the current moment based on the current signal of the magnetic bearing winding at the current moment and the first displacement signal of the rotor at the previous moment; determining a current compensation signal based on the rotor's rotational frequency and the second displacement signal determined by the current signal of the winding at the current moment; and superimposing the current compensation signal and the original current command to obtain a target current command. The method provided by the present invention can extract the rotational frequency and rotor position without installing a position sensor inside the motor, greatly optimizing the motor's structural design and avoiding operational instability and maintenance costs caused by sensor damage. It can effectively implement a vibration suppression algorithm in magnetic bearing systems where sensors are not installed or cannot be installed, effectively suppressing rotor vibration.
Owner:WUHAN INSTITUTE OF MARINE ELECTRIC PROPULSION (THE 712TH RESEARCH INSTITUTE OF CHINA STATE SHIPBUILDING CORP LTD)