Patents by Inventor Daniel C. Ewing

Daniel C. Ewing 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: 5231348
    Abstract: A method and apparatus for testing dynamoelectric machine rotors, particularly squirrel cage rotors for induction motors, to obtain resistance, reactance, and effective skew values to permit identification of rotor defects. The rotor is rotated in an alternating magnetic field and pick-up coils are used to sense the voltage generated in the rotor by sensing the magnetic flux generated by magnetization of the rotor during rotation. Current sensing is used to determine the current used in magnetizing the rotor and a separate skew pick-up coil is utilized to detect effective electrical skew. These signals are processed to determine whether the rotor meets predetermined pass/fail criteria, to provide detailed statistical data and to generate a failure indication responsive to one of the values falling outside respective predetermined limits.
    Type: Grant
    Filed: June 19, 1991
    Date of Patent: July 27, 1993
    Assignee: General Electric Company
    Inventors: Phillip R. Herrick, Daniel C. Ewing, Floyd H. Wright, Kevin M. Truelove
  • Patent number: 5045779
    Abstract: A method and apparatus for testing dynamoelectric machine rotors, particularly squirrel cage rotors for induction motors, to obtain resistance, reactance, and effective skew values to permit identification of rotor defects. The rotor is rotated in an alternating magnetic field and pick-up coils are used to sense the voltage generated in the rotor by sensing the magnetic flux generated by magnetization of the rotor during rotation. Current sensing is used to determine the current used in magnetizing the rotor and a separate skew pick-up coil is utilized to detect effective electrical skew. These signals are processed to determine whether the rotor meets predetermined pass/fail criteria, to provide detailed statistical data and to generate a failure indication responsive to one of the values falling outside respective predetermined limits.
    Type: Grant
    Filed: April 9, 1990
    Date of Patent: September 3, 1991
    Assignee: General Electric Company
    Inventors: Phillip R. Herrick, Daniel C. Ewing, Floyd H. Wright, Kevin M. Truelove
  • Patent number: 4940932
    Abstract: A method and apparatus for testing dynamoelectric machine rotors, particularly squirrel cage rotors for induction motors, to obtain resistance, reactance, and effective skew values to permit identification of rotor defects. The rotor is rotated in an alternating magnetic field and pick-up coils are used to sense the voltage generated in the rotor by sensing the magnetic flux generated by magnetization of the rotor during rotation. Current sensing is used to determine the current used in magnetizing the rotor and a separate skew pick-up coil is utilized to detect effective electrical skew. These signals are processed to determine whether the rotor meets predetermined pass/fail criteria, to provide detailed statistical data and to generate a failure indication responsive to one of the values falling outside respective predetermined limits.
    Type: Grant
    Filed: November 10, 1988
    Date of Patent: July 10, 1990
    Assignee: General Electric Company
    Inventors: Phillip R. Herrick, Daniel C. Ewing, Floyd H. Wright, Kevin M. Truelove
  • Patent number: 4801877
    Abstract: A method and apparatus for testing dynamoelectric machine rotors, particularly squirrel cage rotors for induction motors, to obtain resistance, reactance, and effective skew values to permit identification of rotor defects. The rotor is rotated in an alternating magnetic field and pick-up coils are used to sense the voltage generated in the rotor by sensing the magnetic flux generated by magnetization of the rotor during rotation. Current sensing is used to determine the current used in magnetizing the rotor and a separate skew pick-up coil is utilized to detect effective electrical skew. These signals are processed to determine whether the rotor meets predetermined pass/fail criteria, to provide detailed statistical data and to generate a failure indication responsive to one of the values falling outside respective predetermined limits.
    Type: Grant
    Filed: May 6, 1986
    Date of Patent: January 31, 1989
    Assignee: General Electric Company
    Inventors: Phillip R. Herrick, Daniel C. Ewing, Floyd H. Wright, Kevin M. Truelove