Patents by Inventor James A. Wafer

James A. Wafer 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: 7012350
    Abstract: A switched reluctance machine includes a stator with a plurality of circumferentially-spaced stator segment assemblies that include salient stator poles and inter-polar stator slots. Each of the stator segment assemblies includes a stack of stator plates forming a stator segment core, an end cap assembly, and winding wire wound around the stator segment core and the end cap assembly. The rotor defines a plurality of rotor poles. The rotor tends to rotate relative to the stator to maximize the inductance of an energized winding. A drive circuit energizes the winding wire around the stator segment assemblies based on a rotational position of the rotor. Each stator plate includes a first radially outer rim section and a tooth section that extends radially inwardly from a first center portion of the first radially outer rim section.
    Type: Grant
    Filed: March 12, 2001
    Date of Patent: March 14, 2006
    Assignee: Emerson Electric Co.
    Inventors: C. Theodore Peachee, Donald J. Williams, James A. Wafer, Marielle Piron, Steven P. Randall, Richard S. Wallace, Jr., Michael L. McClelland
  • Patent number: 6897591
    Abstract: A sensorless switched reluctance machine includes a stator with a plurality of circumferentially-spaced stator segment assemblies that include salient stator poles and inter-polar stator slots. Each of the stator segment assemblies includes a stack of stator plates forming a stator segment core, an end cap assembly, and winding wire wound around the stator segment core and the end cap assembly. The rotor defines a plurality of rotor poles. The rotor tends to rotate relative to the stator to a rotational position that maximizes the inductance of an energized winding. A sensorless drive circuit derives rotor position and energizes the winding wire around the stator segment assemblies based on the derived rotor position. Each stator plate includes a first radially outer rim section and a tooth section that extends radially inwardly from a first center portion of the first radially outer rim section.
    Type: Grant
    Filed: March 26, 2001
    Date of Patent: May 24, 2005
    Assignee: Emerson Electric Co.
    Inventors: C. Theodore Peachee, Donald J. Williams, James A. Wafer, Marielle Piron, Steven P. Randall, Richard S. Wallace, Jr., Michael L. McClelland
  • Patent number: 6744166
    Abstract: A winding end cap assembly for an electric machine with a stator and stator poles includes first and second end caps that are connected to opposite axial end surfaces of one of the stator poles. First and second inner winding retainer sections extend axially to connect an inner end of the first end cap to an inner end of the second end cap. The first and second end caps include an outer section, an inner section and a hub section that connects the outer section to the inner section. The first and second end caps and the first and second inner winding retainer sections define a continuous annular channel that receives and retains winding wire. First and second outer retainer sections connect the first and second end caps adjacent to the outer sections or the hub sections of the first and second end caps.
    Type: Grant
    Filed: January 4, 2001
    Date of Patent: June 1, 2004
    Assignee: Emerson Electric Co.
    Inventors: Bernard G. Harter, James A. Wafer, Donald J. Williams
  • Publication number: 20020139606
    Abstract: An electric power steering system for a vehicle includes a steering wheel, a steering shaft connected to said steering wheel, and a switched reluctance motor coupled to said steering shaft. The switched reluctance motor includes a segmented stator having a plurality of stator segment assemblies that define salient stator poles and inter-pole stator slots. Each of the stator segment assemblies includes a stack of stator plates defining a stator segment core, an end cap assembly, and winding wire that is wound around the stator segment core and the end cap assembly. The rotor tends to rotate relative to the stator to a rotational position that maximizes the inductance of an energized winding. A drive circuit energizes the winding wire around the stator segment assemblies based on the rotational position of the rotor.
    Type: Application
    Filed: April 3, 2001
    Publication date: October 3, 2002
    Inventors: Donald J. Williams, James A. Wafer, Marielle Piron, Michael L. McClelland
  • Publication number: 20020135254
    Abstract: A sensorless switched reluctance machine includes a stator with a plurality of circumferentially-spaced stator segment assemblies that include salient stator poles and inter-polar stator slots. Each of the stator segment assemblies includes a stack of stator plates forming a stator segment core, an end cap assembly, and winding wire wound around the stator segment core and the end cap assembly. The rotor defines a plurality of rotor poles. The rotor tends to rotate relative to the stator to a rotational position that maximizes the inductance of an energized winding. A sensorless drive circuit derives rotor position and energizes the winding wire around the stator segment assemblies based on the derived rotor position. Each stator plate includes a first radially outer rim section and a tooth section that extends radially inwardly from a first center portion of the first radially outer rim section.
    Type: Application
    Filed: March 26, 2001
    Publication date: September 26, 2002
    Inventors: C. Theodore Peachee, Donald J. Williams, James A. Wafer, Marielle Piron, Steven P. Randall, Richard S. Wallace, Michael L. McClelland
  • Publication number: 20020125782
    Abstract: A switched reluctance machine includes a stator with a plurality of circumferentially-spaced stator segment assemblies that include salient stator poles and inter-polar stator slots. Each of the stator segment assemblies includes a stack of stator plates forming a stator segment core, an end cap assembly, and winding wire wound around the stator segment core and the end cap assembly. The rotor defines a plurality of rotor poles. The rotor tends to rotate relative to the stator to maximize the inductance of an energized winding. A drive circuit energizes the winding wire around the stator segment assemblies based on a rotational position of the rotor. Each stator plate includes a first radially outer rim section and a tooth section that extends radially inwardly from a first center portion of the first radially outer rim section.
    Type: Application
    Filed: March 12, 2001
    Publication date: September 12, 2002
    Inventors: C. T. Peachee, Donald J. Williams, James A. Wafer, Marielle Piron, Steven P. Randall, Richard S. Wallace, Michael L. McClelland
  • Publication number: 20020093269
    Abstract: A stator for an electric machine such as a motor or a generator includes a plurality of stator segment assemblies. The stator segment assembly includes a stack of stator plates forming a stator segment core. The stator plates include an outer rim section and a tooth section that extends radially inwardly from a center portion of the outer rim section. A radially inner surface of the outer rim section is generally perpendicular to the tooth section. Undercut portions are formed in the radially inner surface of the outer rim section adjacent to the center portion. The undercut portions increase slot area and allow additional winding wire to be wound around the stack. The additional winding wire increases the current carrying capacity of the electric machine through reduced resistance or increased torque per unit volume.
    Type: Application
    Filed: January 16, 2001
    Publication date: July 18, 2002
    Inventors: Bernard G. Harter, Richard E. Hartsfield, James A. Wafer
  • Publication number: 20020084716
    Abstract: A winding end cap assembly for an electric machine with a stator and stator poles includes first and second end caps that are connected to opposite axial end surfaces of one of the stator poles. First and second inner winding retainer sections extend axially to connect an inner end of the first end cap to an inner end of the second end cap. The first and second end caps include an outer section, an inner section and a hub section that connects the outer section to the inner section. The first and second end caps and the first and second inner winding retainer sections define a continuous annular channel that receives and retains winding wire. First and second outer retainer sections connect the first and second end caps adjacent to the outer sections or the hub sections of the first and second end caps.
    Type: Application
    Filed: January 4, 2001
    Publication date: July 4, 2002
    Inventors: Bernard G. Harter, James A. Wafer, Donald J. Williams