Massachusetts Institute of Technology

Satcon Technology Corporation

Chrysler Corporation

Lawrence Livermore National Security, LLC

Apogee Acoustics, Inc.

James L Kirtley, Jr

Gita P Rao

Dariusz Antoni Bushko

Joseph L Smith, Jr

Gary M Colello

David L Trumper

Kevin J Donegan

David B Eisenhaure

Richard T Salter, Ii

Richard C Montesanti

Thomas L Sterling

Richard H Baker

Steven B Leeb

Geoffrey B Lansberry

John R Oleksy

Leo Spiegel

Gerald L Wilson

Kevin M Avakian

Gary E Walker

David C Meeker

Anthony J Shuman

Ronald D Williams

Laban Edward Lesster

A high bandwidth rotary fast tool servo provides tool motion in a direction nominally parallel to the surface-normal of a workpiece at the point of contact between the cutting tool and workpiece. Three or more flexure blades having all ends fixed are used to form an axis of rotation for a swing arm that carries a cutting tool at a set radius from the axis of rotation. An actuator rotates a swing arm assembly such that a cutting tool is moved in and away from the lathe-mounted, rotating workpiece in a rapid and controlled manner in order to machine the workpiece. One or more position sensors provides rotation and position information for a swing arm to a control system. A control system commands and coordinates motion of the fast tool servo with the motion of a spindle, rotating table, cross-feed slide, and in-feed slide of a precision lathe.

Rotary fast tool servo system and methods

The present invention provides a variable reluctance actuator system and method that can be adapted for simultaneous rotation and translation of a moving element by applying a normal-direction magnetic flux on the moving element. In a beneficial example arrangement, the moving element includes a swing arm that carries a cutting tool at a set radius from an axis of rotation so as to produce a rotary fast tool servo that provides a tool motion in a direction substantially parallel to the surface-normal of a workpiece at the point of contact between the cutting tool and workpiece. An actuator rotates a swing arm such that a cutting tool moves toward and away from a mounted rotating workpiece in a controlled manner in order to machine the workpiece. Position sensors provide rotation and displacement information for a swing arm to a control system. A control system commands and coordinates motion of the fast tool servo with the motion of a spindle, rotating table, cross-feed slide, and in feed slide of a precision lathe.

Electromagnetic variable degrees of freedom actuator systems and methods

Several embodiments of an uninterruptible power supply (UPS) system, which system provides highly reliable output power to a load using a slip-ring induction machine and a flywheel combination, are disclosed as well as methods relating thereto. In a preferred embodiment, the UPS system comprises a back-up power source, e.g., an engine and generator, and a slip-ring, or wound-rotor, induction motor and flywheel combination, which are in parallel to a primary power source, e.g., a utility grid. During normal operation of the UPS, the primary power source supplies alternating current and voltage to the load and the UPS compensates for voltage drop across the isolating inductor. Moreover, the primary power source keeps the slip-ring induction machine and flywheel in an excited state, i.e., the rotor of the slip-ring induction machine, the shaft of which is shared by the flywheel, is excited above normal synchronous speed. When the primary power source fails, the flywheel, which is rotating at super-synchronous speed and storing kinetic energy, drives the rotor of the slip-ring induction machine and generates, i.e., induces current in the stator. Accordingly, the flywheel and slip-ring induction machine combination provides instantaneous, short term power to the load until the back-up power source has powered up and been brought on line.

Uninterruptible power supply system using a slip-ring, wound-rotor-type induction machine and a method for flywheel energy storage

Featured is a hybrid permanent magnet/homopolar power producing device and methods related thereto. The device includes first and second portions, the portions being arranged to have a common long axis and so one portion is moving with respect to the other portion. The first portion includes a stator, and a modulating field winding that generates a magnetic field responsive to a DC current therethrough. The second portion includes a support member having a mounting surface, a plurality of permanent magnets and steel poles affixed to the mounting surface, and being arranged thereon so as to form an alteration of steel and permanent magnet poles. The first and second portions and the support member are configured and arranged so each permanent magnet and each steel pole oppose a surface of the stator, so the permanent magnet flux passes between the permanent magnets, the stator and the steel poles, and so the magnetic flux generated by the modulating field winding emerges from each steel pole so as to selectively increase or decrease the permanent magnet flux. The first portion also includes a stator support structure and the first and second portions are configured and arranged so the stator support structure is spaced from the second portion support structure so the flux path between each permanent magnet and an adjacent steel pole is primarily circumferential and so the flux path for flux from the modulating field winding is primarily axial.

Hybrid permanent magnet/homopolar generator and motor

In an induction generator, an additional set of stator windings is provided, separate from and secondary to the main stator windings upon which the generator's output voltage is generated and supplied to the load. This separate stator winding is provided for the purpose of supplying the generator with the reactive electrical power it needs to maintain the rotating stator field and supplying any reactive power needed by the load. Thus, there is no need to use a capacitor assembly, for supplying the reactive power needed by the generator. Currents are injected into this separate winding in such a way that only reactive power is supplied to the generator. Specifically, a power measuring circuit measures the power in the additional set of stator windings, and a power error signal is formed by algebraically adding the outputs of the power measuring circuit. The power error signal is further processed and supplied as a timing control signal for generating the injected currents, which are maintained 90 degrees out of phase with an excitation voltage curve.

Externally field-controlled induction generator

A method for fabricating a stator of an induction motor having a cooling jacket extending around the stator, the method including the steps of welding a channel upper surface and a channel lower surface to an inner channel side surface to create a cooling jacket, coating the inner diameter of the cooling jacket with an oxide layer, heating the cooling jacket to expand the cooling jacket, sliding the cooling jacket over the stator, and cooling the cooling jacket to contact the cooling jacket into positive engagement with the stator such that the cooling jacket is fixedly secured thereto.

Stator fabrication process

An induction motor includes a stator defining stator inner and outer diameters extending about a longitudinal axis, the stator includes a plurality of windings extending longitudinally and circumferentially about the longitudinal axis between the stator inner diameter and the outer diameter and passing an electric current therethrough to create a magnetic field, a rotor extends along the longitudinal axis having a rotor length and a rotor outer diameter less than the stator inner diameter, the rotor being rotatable about the longitudinal axis relative to the stator, the rotor includes at least one electrically conductive bar having a radial outer end and an inner end, the outer end having a notch, the at least one electrically conductive bar extending parallel to the longitudinal axis adjacent the rotor outer diameter for receiving an induced current due to the magnetic field.

Rotor squirrel cage construction

An induction motor includes a stator defining stator inner and stator outer diameters extending about a longitudinal axis, the stator includes a plurality of windings extending longitudinally and circumferentially about the longitudinal axis between the stator inner diameter and the stator outer diameter, passing an electric current therethrough to create a magnetic field, a rotor extending along the longitudinal axis having a rotor length and a rotor outer diameter less than the stator inner diameter, the rotor being rotatable about the longitudinal axis relative to the stator in response to the magnetic field, the rotor including a hoop portion disposed adjacent the rotor outer diameter and extending radially inwardly toward the longitudinal axis, the hoop portion being a solid unitary structure.

Solid rotor assembly

An induction motor includes a stator defining stator inner and stator outer diameters extending about a longitudinal axis, the stator includes a plurality of windings extending longitudinally and circumferentially about the longitudinal axis between the stator inner diameter and the stator outer diameter, passing an electric current therethrough to create a magnetic field, a rotor extending along the longitudinal axis having a rotor length and a rotor outer diameter less than the stator inner diameter, the rotor being rotatable about the longitudinal axis relative to the stator in response to the magnetic field, the rotor including a hoop portion disposed adjacent the rotor outer diameter and extending radially inwardly toward the longitudinal axis, the hoop portion being a solid unitary structure being fabricated of an Aermet alloy material.

The present invention provides a transient event detector for use in a nonintrusive electrical load monitoring system at a monitored site having at least one electrical load. The transient event detector includes a data acquisition portion for acquiring and storing start-up power transient pattern data associated with each electrical load being monitored; a monitor for continuously monitoring total power load pattern data at the site; and a processor for correlating the transient pattern data to the total power load pattern data in order to identify each electrical load.

Transient event detector for use in nonintrusive load monitoring systems

Serial multi-drop data link

The speaker system consists of a single housing containing a tweeter, mid-range and woofer transducer units. The tweeter unit consists of an elongated, aluminum ribbon positioned vertically and connected to the top and bottom of a rigid elongated frame. The ribbon is located between sets of split magnets which are designed to provide a shaped magnetic field that helps center the ribbon in a direction perpendicular to its length. Additional electromagnetic centering is provided by flat ribbon conductors located on the surfaces of the magnets sets which return the current carried by the ribbon. The mid-range transducer is similar to the tweeter transducer in construction except that the edges of the mid-range ribbon are mechanically attached to the frame by foam strips. In addition, the mid-range ribbon is transversely corrugated at variable slant angles relative to ribbon longitudinal axis. The woofer transducer consists of an elongated, trapezoidal, corrugated aluminum ribbon attached to a non-vibrating frame. In order to provide a single electrical path, the ribbon is divided into a serpentine path by a series of cuts. To prevent undesirable auto effects, the ribbon is tensioned in a transverse direction.

Ribbon speaker system

A dynamic rate integrating demand monitor which measures electric power to a customer load at closely-spaced time intervals and prices that load at each such interval on the basis of a predetermined set of factors.

Dynamic rate integrating demand monitor

A rotating electric machine in which the armature winding thereof and other parts are supported by a liquid to withstand the mechanical stresses applied during transient overloads and the like. In particular, a narrow gap is provided between the armature winding and the stator which supports it and this gap is filled with an externally pressurized viscous liquid. The liquid is externally pressurized sufficiently to balance the static loads on the armature winding. Transient mechanical loads which deform the armature winding alter the gap dimensions and thereby additionally pressurize the viscous liquid to oppose the armature winding deformation and more nearly uniformly to distribute the resulting mechanical stresses.

Rotating electric machine with fluid supported parts

A variable speed electronic motor which may be powered by an ac or dc source and wherein both the speed of the motor and the input power thereto are controlled and related to one another.

Growing community of inventors

Brookline, MA, United States of America

James L Kirtley, Jr