Mitsubishi Electric Research Laboratories, Inc.

Massachusetts Institute of Technology

Asml Netherlands B.v.

Mitsubishi Electric Corporation

Lei Zhou

Bingnan Wang

David L Trumper

Yebin Wang

Chungwei Lin

Hongyu Wang

Ruvinda Gunawardana

Koon Hoo Teo

Hiroshi Inoue

Dehong Liu

An abnormality diagnosis device includes: a first interface to obtain a value of a driving current for driving a motor; and a processor to access a database including calculation data to be used to calculate a degree of abnormality of the motor, wherein the processor extracts a feature quantity for calculating the degree of abnormality from a current waveform specified by a value of the driving current, and calculates the degree of abnormality of the motor based on the extracted feature quantity and the calculation data.

Abnormality diagnosis device and abnormality diagnosis method

A reticle transport system having a magnetically levitated transportation stage is disclosed. Such a system may be suitable for use in vacuum environments, for example, ultra-clean vacuum environments. A magnetic levitated linear motor functions to propel the transportation stage in a linear direction along a defined axis of travel and to magnetically levitate the transportation stage.

Transport system having a magnetically levitated transportation stage

An electrical machine that is an outer runner motor having a rotor mounted rotatably about a machine axis, with the rotor rotatively attached to a shaft. A stator assembly having a stator core with a non-ferromagnetic material. An axial-flux yoke with an inner wall rigidly attached on an outer surface of a first edge wall of the stator core, or a radial-flux yoke with a continuous inner wall rigidly attached on a continuous outer wall of the stator core. Wherein the axial-flux yoke or the radial-flux yoke, include laminated sheets and slots. Windings can be positioned in the slots of either the axial-flux stator yoke or the radial-flux stator yoke. Wherein the stator core and the shaft include a spline coupling feature adapted to selectively couple and mate the stator core to the shaft.

Motor designs having spline structure connecting motor shaft and stator structure

A motor comprising a shaft, an array of stator assemblies rigidly attached to the shaft, each stator assembly includes a stator yoke having a toroid shape fixed around the shaft and having a number of slots at radial and axis directional faces with windings within the slots of the stator yoke, and a rotor assembly rotatively attached to the shaft to enclose the array of stator assemblies, the rotor assembly has a rotor drum with sections, each section embraces one stator assembly, each section has two axial-flux permanent magnet arrays attached on axial-directional inner surfaces of the section and has one radial-flux permanent magnet array attached on a radial-directional inner surface of the section furthest from the shaft, wherein the axial-flux and the radial-flux permanent magnet arrays with the number of pole pairs equals the number of the stator slots plus or minus the number of stator winding pole pair.

Multi-layer axial and radial flux vernier permanent magnet motor

An axial-flux and radial-flux motor including a rotor mounted rotatably about a machine axis, with the rotor rotatively attached to a shaft. A stator assembly having a core with a non-ferromagnetic material and including a first axial-flux stator yoke with an inner wall rigidly attached on an outer surface of a first edge wall of the core. A second axial-flux stator yoke having an inner wall rigidly attached on an outer surface of a second edge wall of the core. The first and the second axial-flux stator yokes each include an outer wall with slots. A radial-flux stator yoke with slots includes an inner wall rigidly attached on a continuous outer wall of the core. The radial-flux stator yoke and the first and the second axial-flux stator yokes include laminated sheets. Windings positioned in the slots of the first and the second axial-flux stator yokes and the radial-flux stator yoke.

Electric machine with combined axial- and radial-flux

A system for controlling an operation of an induction motor (IM). A controller processor detects a spectrum of a current signal from received sensor data using a module. Obtain a number of rotor bars and a number of pole pairs of the IM to identify a principle slot harmonics (PSH) type IM from stored IM data. Use the PSH-type IM to identify a static eccentricity (SE) fault signature signal located at a secondary PSH frequency of the PSH-type IM. Determine a level of signal strength in the spectrum of the current signal at a location of the secondary PSH frequency, and compare to a SE fault table database to obtain a SE fault level of the PSH-type IM. Compare the SE fault level to a database to obtain a SE fault threshold, and if the SE fault level is outside the SE threshold, generate an interrupt command to the controller.

Method for static eccentricity fault detection of induction motors

Described herein is a magnetically levitated linear transportation stage which utilizes a permanent magnet bias flux to generate a passive magnetic/suspension force/torque in a first set of directions orthogonal to a direction of transportation stage travel, a motor flux which forms a traveling wave along a direction of transportation stage travel and a suspension control force orthogonal to the direction of transportation stage travel. Such a magnetically levitated linear transportation stage is suitable for use in in-vacuum transportation tasks such as in conjunction with photo lithography systems (e.g. extreme ultra violet (EUV) machines).

Magnetically-levitated transporter

An electric motor is controlled using a feedback signal that includes an error between the measured current and the estimated current determined using the measured current, the measured voltage, and a model of the motor. A feedback gain is determined as an error function of a feedback signal and a speed of the motor is estimated using a product of the feedback gain and the feedback signal. The voltage of the motor is determined using a difference between the estimated speed of the motor and a reference speed of the motor and the motor us controlled using the determined voltage.

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Cambridge, MA, United States of America

Lei Zhou