Patents by Inventor Gita P. Rao

Gita P. Rao has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6262505
    Abstract: A power supply device for providing uninterrupted power for a period of time is disclosed. The power supply device has a controller and a flywheel device. The flywheel device has a housing that contains a flywheel rotor and a motor/generator rotor. The flywheel rotor and the motor/generator rotor are mounted on a common shaft. An active axial magnetic bearing is located to support the shaft for frictionless rotation. The bearing provides support for the shaft, the flywheel rotor and motor/generator rotor. The axial magnetic bearing is attached to the housing and provides, in combination with the motor/generator rotor, a flux path and magnetic field to exert a magnetic force to lift the motor/generator rotor and the shaft on which it is mounted.
    Type: Grant
    Filed: March 26, 1997
    Date of Patent: July 17, 2001
    Assignee: SatCon Technology Corporation
    Inventors: Richard L. Hockney, Stephen B. Nichols, Geoffrey B. Lansberry, Francis E. Nimblett, Dariusz A. Bushko, Gita P. Rao, Luka Serdar, Michael E. Amaral, William E. Stanton, James O'Rourke
  • Patent number: 6097124
    Abstract: 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.
    Type: Grant
    Filed: October 23, 1997
    Date of Patent: August 1, 2000
    Assignee: Satcon Technology Corporation
    Inventors: Gita P. Rao, James L. Kirtley, Jr., David C. Meeker, Kevin J. Donegan
  • Patent number: 5969446
    Abstract: A flywheel energy storage device has a central shaft, a flywheel having a flywheel rotor supported by and mounted for rotation around said shaft, and a motor/generator having a stator and a rotor. The rotor is formed integrally with the flywheel rotor. The stator has an outer cylinder that is cooled by a liquid flowing in contact with its cylindrical surface. Preferably, the stator has (i) a cylindrical hub having an outer surface and longitudinal channels formed therein, (ii) a cylinder surrounding said cylindrical hub thereby providing passages through the channels, and (iii) end caps sealing the passages and providing a distribution channel for distributing fluid to said passages, thereby providing fluid cooling passages for said stator. A radial vibration dampener can be positioned at one or both ends of the shaft. The dampener has a plurality of spring members positioned between two cylindrical surfaces, one end of each spring member being attached to each cylindrical surface.
    Type: Grant
    Filed: March 26, 1998
    Date of Patent: October 19, 1999
    Assignee: Satcon Technology Corporation
    Inventors: David B. Eisenhaure, Richard L. Hockney, Gary Colello, Vijay Gondhalekar, Gita P. Rao
  • Patent number: 5929612
    Abstract: 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.
    Type: Grant
    Filed: July 3, 1997
    Date of Patent: July 27, 1999
    Assignee: Satcon Technology Corporation
    Inventors: David B. Eisenhaure, James L. Kirtley, Jr., Geoffrey B. Lansberry, Kevin J. Donegan, Gita P. Rao
  • Patent number: 5852865
    Abstract: 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.
    Type: Grant
    Filed: May 2, 1996
    Date of Patent: December 29, 1998
    Assignee: Chrysler Corporation
    Inventors: James L. Kirtley, Jr., Gita P. Rao, Dariusz A. Bushko, John R. Oleksy
  • Patent number: 5808391
    Abstract: 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.
    Type: Grant
    Filed: September 19, 1996
    Date of Patent: September 15, 1998
    Assignee: Chrysler Corporation
    Inventors: Kevin M. Avakian, James L. Kirtley, Jr., Gita P. Rao, Dariusz A. Bushko, Gary Colello
  • Patent number: 5798593
    Abstract: 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.
    Type: Grant
    Filed: May 2, 1996
    Date of Patent: August 25, 1998
    Assignee: SatCon Technology Corporation
    Inventors: Richard T. Salter, II, James L. Kirtley, Jr., Gita P. Rao, Dariusz A. Bushko, Gary Colello
  • Patent number: 5793145
    Abstract: 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 stator 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 including 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, an end cap at each end of the rotor contacting the at least one electrically conductive bar and a capture ring attached to each end of the rotor to prevent movement between the end caps and the rotor.
    Type: Grant
    Filed: July 11, 1996
    Date of Patent: August 11, 1998
    Assignee: Chrysler Corporation
    Inventors: Kevin M. Avakian, Gita P. Rao, Dariusz A. Bushko, John R. Oleksy
  • Patent number: 5793142
    Abstract: 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.
    Type: Grant
    Filed: July 11, 1996
    Date of Patent: August 11, 1998
    Assignee: Chrysler Corporation
    Inventors: Richard T. Salter, II, James L. Kirtley, Jr., Gita P. Rao, Dariusz A. Bushko, Gary Colello
  • Patent number: 5784927
    Abstract: The present invention is an energy storage apparatus. The energy storage apparatus includes a hub rotatably positioned about a stationary axial shaft. The hub supports a rotor. The rotor includes a plurality of balance bars positioned on the rotor to compensate for any stress imbalance of the rotor.
    Type: Grant
    Filed: May 2, 1996
    Date of Patent: July 28, 1998
    Inventors: Gita P. Rao, Gary M. Colello, Clifford Gunsallus
  • Patent number: 5721459
    Abstract: The present invention is an energy storage apparatus. The energy storage apparatus includes a stator that is stationary. The stator includes a winding encircling the stator for generating an output voltage. The energy storage apparatus also includes a rotor rotating relative to the stator. The rotor includes a plurality of magnets on a surface of the rotor adjacent to the stator. The rotor and stator include a gap between the magnets and the stator. The magnets are a source for the output voltage generated in the winding. The output voltage generated is dependent on the gap and the speed of the rotor. The energy storage apparatus uses centrifugal growth to regulate the output voltage.
    Type: Grant
    Filed: May 2, 1996
    Date of Patent: February 24, 1998
    Assignee: Chrysler Corporation
    Inventors: Gita P. Rao, Richard L. Hockney