Patents by Inventor Madhusudan Raghavan

Madhusudan Raghavan 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).

  • 8-Speed Transmission
    Patent number: 7736259
    Abstract: The transmission has a plurality of members that can be utilized in powertrains to provide eight forward speed ratios and one reverse speed ratio. The transmission includes three planetary gear sets having six torque-transmitting devices, a fixed interconnection and a grounded member. The powertrain includes an engine and torque converter that is selectively connected to at least one of the planetary gear members and an output member that is continuously connected with another one of the planetary gear members. The six torque-transmitting devices provide interconnections between various gear members, the transmission housing and with the input member, and are operated in combinations of three to establish at least eight forward speed ratios and at least one reverse speed ratio.
    Type: Grant
    Filed: August 24, 2007
    Date of Patent: June 15, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Scott H. Wittkopp, Andrew W. Phillips, Clinton E. Carey, James M. Hart, Madhusudan Raghavan
  • 8-speed transmission
    Patent number: 7731621
    Abstract: The transmission has a plurality of members that can be utilized in powertrains to provide eight forward speed ratios and one reverse speed ratio. The transmission includes three planetary gear sets, six torque-transmitting devices, and two fixed interconnections. The powertrain includes an engine and torque converter that is continuously connected to one of the planetary gear members and an output member that is continuously connected with another one of the planetary gear members. The six torque-transmitting devices provide interconnections between various gear members, and the transmission housing, and are operated in combinations of three to establish eight forward speed ratios and one reverse speed ratio.
    Type: Grant
    Filed: July 20, 2007
    Date of Patent: June 8, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Scott H. Wittkopp, James M. Hart, Andrew W. Phillips, Clinton E. Carey, Madhusudan Raghavan
  • 8-speed transmissions
    Patent number: 7731622
    Abstract: The transmission has a plurality of members that can be utilized in powertrains to provide eight forward speed ratios and one reverse speed ratio. The transmission includes three planetary gear sets, six torque-transmitting devices, one fixed interconnection and a grounded member. The powertrain includes an engine and torque converter that is continuously connected to one of the planetary gear members and an output member that is continuously connected with another one of the planetary gear members. The six torque-transmitting devices provide interconnections between various gear members, and the transmission housing, and are operated in combinations of three to establish eight forward speed ratios and one reverse speed ratio.
    Type: Grant
    Filed: July 20, 2007
    Date of Patent: June 8, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Scott H. Wittkopp, James M. Hart, Andrew W. Phillips, Clinton E. Carey, Madhusudan Raghavan
  • 8-speed transmission
    Patent number: 7727102
    Abstract: The transmission has a plurality of members that can be utilized in powertrains to provide eight forward speed ratios and one reverse speed ratio. The transmission includes four planetary gear sets having five torque-transmitting devices, two fixed interconnections and two grounded members. The powertrain includes an engine and torque converter that is continuously connected to at least one of the planetary gear members and an output member that is continuously connected with another one of the planetary gear members. The five torque-transmitting devices provide interconnections between various gear members, and are operated in combinations of three to establish at least eight forward speed ratios and at least one reverse speed ratio.
    Type: Grant
    Filed: August 24, 2007
    Date of Patent: June 1, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Andrew W. Phillips, Clinton E. Carey, James M. Hart, Scott H. Wittkopp, Madhusudan Raghavan
  • Electrically variable transmissions having two planetary gear sets and clutched input
    Patent number: 7717817
    Abstract: The electrically variable transmission family of the present invention provides low-content, low-cost electrically variable transmission mechanisms including first and second differential gear sets, a battery, two electric machines serving interchangeably as motors or generators, four or five selectable torque transmitting devices, and possibly a dog clutch. The selectable torque transmitting devices are engaged to yield an EVT with a continuously variable range of speeds (including reverse) and at least one mechanically fixed forward speed ratio. The torque transmitting devices and the first and second motor/generators are operable to provide five operating modes in the electrically variable transmission, including battery reverse mode, EVT reverse mode, reverse and forward launch modes, continuously variable transmission range mode, and fixed ratio mode.
    Type: Grant
    Filed: June 17, 2008
    Date of Patent: May 18, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Madhusudan Raghavan, Norman K. Bucknor
  • Multi-speed transmission
    Patent number: 7704180
    Abstract: A transmission is provided having an input member, an output member, four planetary gear sets, a plurality of coupling members and a plurality of torque transmitting devices. Each of the planetary gear sets includes first, second and third members. The torque transmitting devices may include clutches and brakes.
    Type: Grant
    Filed: December 12, 2007
    Date of Patent: April 27, 2010
    Assignee: GM Global Technology Operations Inc.
    Inventors: Scott H. Wittkopp, James M. Hart, Andrew W. Phillips, Clinton E. Carey, Madhusudan Raghavan
  • Multi-speed transmissions with a long pinion and one fixed interconnection
    Patent number: 7699745
    Abstract: The family of transmissions has a plurality of members that can be utilized in powertrains to provide at least five forward speed ratios and one reverse speed ratio. The transmission family members include three planetary gear sets having up to seven torque-transmitting mechanisms and three interconnecting members. The powertrain includes an engine that is selectively or continuously connectable to at least one of the planetary gear members and an output shaft that is continuously connected with another one of the planetary gear members. The torque-transmitting mechanisms provide interconnections between various gear members, the input shaft and the transmission housing, and are operated in combinations of two to establish at least five forward speed ratios and at least one reverse speed ratio.
    Type: Grant
    Filed: May 25, 2006
    Date of Patent: April 20, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventor: Madhusudan Raghavan
  • Multi-speed transmission
    Patent number: 7699741
    Abstract: A transmission is disclosed having an input member, an output member, a plurality of planetary gear sets, a plurality of interconnecting members and a plurality of torque-transmitting mechanisms. The plurality of planetary gear sets has first, second and third members. The input member is continuously interconnected with a member of the planetary gear sets. The output member is continuously interconnected with another member of the planetary gear sets. At least eight forward speeds and one reverse speed are produced by the selective engagement of the five torque-transmitting mechanisms.
    Type: Grant
    Filed: March 21, 2007
    Date of Patent: April 20, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: James M. Hart, James B. Borgerson, Scott H. Wittkopp, Andrew W. Phillips, Clinton E. Carey, Madhusudan Raghavan
  • 8-speed transmission with two fixed interconnections and on grounded member
    Patent number: 7699742
    Abstract: The transmission has a plurality of members that can be utilized in powertrains to provide eight forward speed ratios and one reverse speed ratio. The transmission includes three planetary gear sets having five torque-transmitting mechanisms, two fixed interconnections and a grounded member. The powertrain includes an engine and torque converter that is continuously connected to at least one of the planetary gear members and an output member that is continuously connected with another one of the planetary gear members. The five torque-transmitting mechanisms provide interconnections between various gear members, and with the transmission housing, and are operated in combinations to establish eight forward speed ratios and one reverse speed ratio.
    Type: Grant
    Filed: October 5, 2007
    Date of Patent: April 20, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: James M. Hart, Andrew W. Phillips, Clinton E. Carey, Scott H. Wittkopp, Madhusudan Raghavan
  • 8-speed transmission
    Patent number: 7695397
    Abstract: The transmission has a plurality of members that can be utilized in powertrains to provide eight forward speed ratios and one reverse speed ratio. The transmission includes three planetary gear sets having six torque-transmitting mechanisms and two fixed interconnections. The powertrain includes an engine and torque converter that is continuously connected to one of the planetary gear members and an output member that is continuously connected with another one of the planetary gear members. The six torque-transmitting mechanisms provide interconnections between various gear members, the transmission housing and with the input member, and are operated in combinations of three to establish eight forward speed ratios and one reverse speed ratio.
    Type: Grant
    Filed: June 4, 2007
    Date of Patent: April 13, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: James M. Hart, Andrew W. Phillips, Clinton E. Carey, Scott H. Wittkopp, Madhusudan Raghavan
  • Wide ratio transmissions with multiple gear ratios
    Patent number: 7686732
    Abstract: The transmission has a plurality of members that can be utilized in powertrains to provide at least seven forward speed ratios and one reverse speed ratio. The transmission includes three planetary gear sets having seven torque-transmitting mechanisms and two fixed interconnections. The powertrain includes an engine and torque converter that is continuously connected to at least one of the planetary gear members and an output member that is continuously connected with another one of the planetary gear members. The seven torque-transmitting mechanisms provide interconnections between various gear members and with the transmission housing, and are operated in combinations of three to establish at least seven forward speed ratios and at least one reverse speed ratio.
    Type: Grant
    Filed: February 23, 2007
    Date of Patent: March 30, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Madhusudan Raghavan, Norman K. Bucknor
  • Wide ratio transmission with four planetary gear sets and three fixed interconnections
    Patent number: 7686731
    Abstract: The transmission has a plurality of members that can be utilized in powertrains to provide at least eight forward speed ratios and one reverse speed ratio. The transmission includes four planetary gear sets having seven torque-transmitting mechanisms and tree fixed interconnections. The powertrain includes an engine and torque converter that is continuously connected to at least one of the planetary gear members and an output member that is continuously connected with another one of the planetary gear members. The seven torque-transmitting mechanisms provide interconnections between various gear members and with the transmission housing, and are operated in combinations of two to establish at least eight forward speed ratios and one reverse speed ratio.
    Type: Grant
    Filed: March 14, 2007
    Date of Patent: March 30, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventor: Madhusudan Raghavan
  • 8-speed transmission
    Patent number: 7678009
    Abstract: The transmission has a plurality of members that can be utilized in powertrains to provide eight forward speed ratios and one reverse speed ratio. The transmission includes three planetary gear sets having six torque-transmitting mechanisms and two fixed interconnections. The powertrain includes an engine and torque converter that is continuously connected to one of the planetary gear members and an output member that is continuously connected with another one of the planetary gear members. The six torque-transmitting mechanisms provide interconnections between various gear members, the transmission housing and with the input member, and are operated in combinations of three to establish eight forward speed ratios and one reverse speed ratio.
    Type: Grant
    Filed: May 21, 2007
    Date of Patent: March 16, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Andrew W. Phillips, Clinton E. Carey, James M. Hart, Scott H. Wittkopp, Madhusudan Raghavan
  • Wide ratio transmissions having multiple gear ratios
    Patent number: 7674201
    Abstract: The transmission has a plurality of members that can be utilized in powertrains to provide at least seven forward speed ratios and one reverse speed ratio. The transmission includes three planetary gear sets having six or seven torque-transmitting mechanisms and three fixed interconnections. The powertrain includes an engine and torque converter that is continuously connected to at least one of the planetary gear members and an output member that is continuously connected with another one of the planetary gear members. The six or seven torque-transmitting mechanisms provide interconnections between various gear members and with the transmission housing, and are operated in combinations of two to establish at least seven forward speed ratios and at least one reverse speed ratio.
    Type: Grant
    Filed: May 4, 2007
    Date of Patent: March 9, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Norman K. Bucknor, Madhusudan Raghavan
  • Eight speed transmission
    Patent number: 7674202
    Abstract: An eight speed automatic transmission is provided having an input member, an output member, three planetary gear sets, a plurality of coupling members and a plurality of torque transmitting devices. Each of the planetary gear sets includes first, second and third members. The torque transmitting devices include three clutches and three brakes.
    Type: Grant
    Filed: June 1, 2007
    Date of Patent: March 9, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Scott H. Wittkopp, Madhusudan Raghavan, James M. Hart
  • Electrically variable transmission having three planetary gear sets with two fixed interconnections
    Patent number: 7670242
    Abstract: The electrically variable transmission family provides low-content, low-cost electrically variable transmission mechanisms including first, second and third differential gear sets, a battery, two electric machines serving interchangeably as motors or generators, and five selectable torque-transfer devices. The selectable torque transfer devices are engaged in combinations of two or three to yield an EVT with a continuously variable range of speeds (including reverse) and four or five mechanically fixed forward speed ratios. The torque transfer devices and the first and second motor/generators are operable to provide five operating modes in the electrically variable transmission, including battery reverse mode, EVT reverse mode, reverse and forward launch modes, continuously variable transmission range mode, and fixed ratio mode.
    Type: Grant
    Filed: December 17, 2008
    Date of Patent: March 2, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Norman K. Bucknor, Madhusudan Raghavan
  • 8-speed transmission
    Patent number: 7651434
    Abstract: The transmission has a plurality of members that can be utilized in powertrains to provide eight forward speed ratios and one reverse speed ratio. The transmission includes three planetary gear sets having six torque-transmitting mechanisms, two fixed interconnections and a grounded member. The powertrain includes an engine and torque converter that is selectively connected to at least one of the planetary gear members and an output member that is continuously connected with another one of the planetary gear members. The six torque-transmitting mechanisms provide interconnections between various gear members, the transmission housing and with the input member, and are operated in combinations of three to establish eight forward speed ratios and one reverse speed ratio.
    Type: Grant
    Filed: May 1, 2007
    Date of Patent: January 26, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Clinton E. Carey, James M. Hart, Andrew W. Phillips, Madhusudan Raghavan, Scott H. Wittkopp
  • Multi-mode electrically variable transmissions with interconnected gearsets
    Patent number: 7648437
    Abstract: The electrically variable transmission family of the present invention provides low-content, low-cost electrically variable transmission mechanisms including first, second and third differential gear sets, a battery, two electric machines serving interchangeably as motors or generators and four selectable torque-transfer devices. The selectable torque transmitting devices are engaged to yield an EVT with a continuously variable range of speeds (including reverse) and four mechanically fixed forward speed ratios. The torque transmitting devices and the first and second motor/generators are operable to provide five operating modes in the electrically variable transmission, including battery reverse mode, EVT reverse mode, reverse and forward launch modes, continuously variable transmission range mode, and fixed ratio mode.
    Type: Grant
    Filed: September 28, 2006
    Date of Patent: January 19, 2010
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Madhusudan Raghavan, Alan G. Holmes
  • Hybrid powertrain
    Patent number: 7611432
    Abstract: A powertrain is provided, comprising: an internal combustion engine and an electro-mechanical transmission. The internal combustion engine has two torque output nodes operatively connected to two torque input nodes of the electro-mechanical transmission. The transmission comprises first and second electrical machines operatively connected to first and second planetary gear sets that are selectively operative to transmit torque to an output shaft. The two torque output nodes of the engine comprise an engine block comprising a cylinder with a pair of opposed pistons inserted therein, and each piston operatively connected to one of a first and a second crankshaft. The first and second crankshafts are operatively connected.
    Type: Grant
    Filed: August 8, 2006
    Date of Patent: November 3, 2009
    Assignee: GM Global Technology Operations, Inc.
    Inventors: Joel M. Maguire, Norman K. Bucknor, Madhusudan Raghavan, Paul M. Najt
  • EIGHT SPEED AUTOMATIC TRANSMISSION
    Publication number: 20090264244
    Abstract: A transmission is disclosed having an input member, an output member, four planetary gear sets, a plurality of coupling members and a plurality of torque transmitting devices. Each of the planetary gear sets includes first, second and third members. The torque transmitting devices may include clutches and brakes.
    Type: Application
    Filed: October 23, 2008
    Publication date: October 22, 2009
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.
    Inventors: JAMES M. HART, SCOTT H. WITTKOPP, ANDREW W. PHILLIPS, CLINTON E. CAREY, MADHUSUDAN RAGHAVAN