Patents by Inventor Balarama Murty

Balarama Murty 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).

  • Publication number: 20070234980
    Abstract: An engine coolant pump drive system for a vehicle having an engine, an engine coolant system, and at least one sensor for sensing at least one operational condition of the vehicle is disclosed. The pump drive system includes a magnetorheological fluid (MRF) clutch, and a coolant pump. The MRF clutch includes a torque input section coupled to a torque output section via a MRF, the torque input section being configured to receive a torque input from the engine. The coolant pump is configured for operable communication with the torque output section of the MRF clutch. In response to a signal from the at least one sensor, the MRF clutch is configured to provide a continuously variable torque transfer from the torque input section to the torque output section, thereby providing for variable coolant flow in the engine coolant system via the coolant pump capable of a continuously variable speed.
    Type: Application
    Filed: April 6, 2006
    Publication date: October 11, 2007
    Inventors: Chandra Namuduri, David Rule, Balarama Murty
  • Publication number: 20060254871
    Abstract: A magneto-rheological coupling (MRC) having an input assembly and an output member. The output member includes a generally cylindrical drum portion and a hub portion extending radially inwardly therefrom. The generally cylindrical drum portion has a low magnetically permeable region having a plurality of passages defined therein. Additionally, a plurality of apertures are defined by the hub portion. The plurality of passages and apertures enhance the flow of magneto-rheological fluid (MRF) within the MRC. The drum portion has a surface treatment of tungsten-carbide to enhance wear resistance. Additionally, the drum portion has an average roughness, or Ra value, of between 10 and 250 microns.
    Type: Application
    Filed: January 27, 2006
    Publication date: November 16, 2006
    Inventors: Balarama Murty, Chandra Namuduri, Kenneth Shoemaker
  • Publication number: 20060259221
    Abstract: A method of controlling a magneto-rheological power steering coupling is provided. The method is to be employed by a controller and is initiated upon engine start-up. The method includes initializing calibration parameters and reading a plurality of input values. Subsequently, a hand wheel angle rate value is calculated from one of said plurality of input values. A pump speed command value is calculated as a function of at least the hand wheel angle rate value. A pump speed error value is then calculated, and a proportional-integral-derivative calculation is performed acting on the pump speed error value to determine a pulse width modulation duty cycle value. The duty cycle value is then output to a power driver to provide a control signal to the magneto-rheological power steering coupling. Also provided is control system and apparatus operable to perform the functions described hereinabove.
    Type: Application
    Filed: February 10, 2006
    Publication date: November 16, 2006
    Inventors: Balarama Murty, Chandra Namuduri, Kenneth Shoemaker
  • Publication number: 20060254870
    Abstract: A magneto-rheological coupling (MRC) is provided having an input assembly operable to receive a torque input and an output member operable to selectively transmit torque to a driveshaft. A magneto-rheological fluid, or MRF, having a variable viscosity in response to a magnetic flux field is operable to vary the torque transmitted from the input assembly to the output member. At least one annular lip forming a magneto-rheological fluid retention pocket is provided on at least one of the input assembly and the output member of the MRC. The annular lip is operable to direct MRF away from a roller bearing, thereby reducing the likelihood of MRF fluid incursion within the roller bearing. Additionally, a labyrinth seal may be employed to provide additional protection to the bearing. The labyrinth seal may have an annular bushing disposed therein to reduce the clearances of the labyrinth seal.
    Type: Application
    Filed: October 7, 2005
    Publication date: November 16, 2006
    Inventors: Balarama Murty, Chandra Namuduri, Jie Tong, Kenneth Shoemaker
  • Publication number: 20060052198
    Abstract: A magnetorheological (MR) fluid coupling for vectoring torque with respect to a shaft capable of rotary motion is disclosed. The coupling includes a stator, a rotor having a rotational degree of freedom with respect to the stator and configured for physical communication with the shaft, and a magnetic field generator. The stator and rotor define an annular space therebetween and are coupled via a MR fluid disposed within the annular space. The magnetic field generator is in field communication with the MR fluid and is disposed to produce a substantially radially directed magnetic field across the annular space. The rotor is rotationally responsive to the application of a magnetic field at the MR fluid.
    Type: Application
    Filed: April 22, 2005
    Publication date: March 9, 2006
    Inventors: Chandra Namuduri, Balarama Murty, Anthony Smith, Jie Tong, Mark Golden, John Ulicny
  • Publication number: 20060017290
    Abstract: A belted-alternator starter system that continuously provides pre-flux when the vehicle ignition is on and the engine is off to provide a faster torque response when the engine is turned on. The alternator/starter device operates as an alternator for providing electrical energy to vehicle electrical devices and the battery when the ignition is on and the engine is running, and operates as a starter for providing engine torque to start the engine when the engine is off and the ignition is on. The system further includes an inverter/rectifier circuit to provide AC current to the armature coils when the alternator/starter device is operating as a starter. The system provides an operating field current to the field coil when the ignition and the engine are on and provides a pre-flux field current to the field coil when the vehicle ignition is on and the engine is off.
    Type: Application
    Filed: July 26, 2004
    Publication date: January 26, 2006
    Inventors: Balarama Murty, Chandra Namuduri
  • Publication number: 20050188690
    Abstract: A magneto-rheological hydraulic power steering system for a vehicle includes a magneto-rheological power steering pump interconnecting a power steering gear of the vehicle and a drive shaft of an engine of the vehicle. The magneto-rheological hydraulic power steering system also includes a controller operatively connected to the magneto-rheological power steering pump to generate a current signal to vary a speed of the magneto-rheological power steering pump.
    Type: Application
    Filed: April 1, 2005
    Publication date: September 1, 2005
    Inventors: Chandra Namuduri, Balarama Murty, Jie Tong
  • Patent number: 4544868
    Abstract: The voltage supplied to the stator windings of a brushless DC motor is pulse-width-modulated by a circuit which interrupts the energization thereof for a predetermined period of time whenever the DC line current supplied thereto exceeds a current reference. The frequency and off/on duty cycle of the applied voltage is relatively high near zero speed to produce smooth motor starting torque and decreases with increasing motor speed. The pulse-width-modulation effects regenerative braking whenever the stator winding energization sequence is changed to reverse the direction of motor rotation.
    Type: Grant
    Filed: July 20, 1984
    Date of Patent: October 1, 1985
    Assignee: General Motors Corporation
    Inventor: V. Balarama Murty