Patents by Inventor Vijay A. Neelakantan
Vijay A. Neelakantan 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).
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Patent number: 8037989Abstract: A hydraulic control system for actuating a torque transmitting device in a transmission includes a sump for receiving a hydraulic fluid and a piezoelectric pump for pumping the hydraulic fluid from the sump to the torque transmitting device. A first fluid flow path communicates the hydraulic fluid from the sump to the piezoelectric pump and a second fluid flow path communicates the hydraulic fluid from the piezoelectric pump to the torque transmitting device. An exhaust means selectively communicates the hydraulic fluid from the torque transmitting device to the sump.Type: GrantFiled: July 25, 2008Date of Patent: October 18, 2011Assignee: GM Global Technology Operations LLCInventors: Vijay A. Neelakantan, John C. Schultz, Bret M. Olson, Hamid Vahabzadeh, Robert L. Moses
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Publication number: 20110203401Abstract: A multiplexed electromechanical shift mechanism includes a single linear actuator with multiple independently selectable linkages actuating a clutch and multiple gears for use in motor vehicle transmissions such as a dual clutch transmission. The linear actuator may be a ball screw, a planetary roller screw or hydraulic or pneumatic operator capable of controlling bi-directional linear motion of an output member. A plurality of linear clutches selectively couple the output member to one of a plurality of linkages adapted to transfer the bi-directional motion of the output member. One of the linkages is coupled to and engages an input (main) clutch of the transmission and the remaining linkages are coupled to and bi-directionally translate shift forks and synchronizer clutches which achieve gear selection and engagement.Type: ApplicationFiled: February 23, 2010Publication date: August 25, 2011Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventors: Vijay A. Neelakantan, Bret M. Olson, James W. Haynes, Clinton E. Carey
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Publication number: 20110208396Abstract: The present invention provides an apparatus and method for estimating the realtime position of a clutch piston during the fill cycle using noisy pressure measurements which ensures proper and desired clutch operation. Pressures on both sides of a flow controlling orifice, at the fluid control actuator and the clutch cylinder are measured and these measurements in conjunction with other system parameters such as orifice size, clutch volume and return spring characteristics are used to solve nonlinear dynamic equations (algorithms) which reside in a microprocessor. The microprocessor provides outputs corresponding to an estimate of the current position of the clutch piston, an estimate of the current speed of the piston and an estimate of the current hydraulic pressure. The method can also be utilized to detect clutch wear.Type: ApplicationFiled: February 23, 2010Publication date: August 25, 2011Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventors: Paul G. Otanez, Shushan Bai, Vijay A. Neelakantan, Yue-Ming Chen
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Publication number: 20110195794Abstract: A system for absorbing vibration created by operation of an engine of the present invention includes a first plate driven by an engine shaft and a torque transmitting device for transferring torque from the engine shaft to a transmission input shaft. The system includes a first vibration absorber and a second vibration absorber. The first vibration absorber includes at least one selectively moveable mass. The second vibration absorber includes at least one biasing member and generally opposing ends. The first vibration absorber is configured to absorb vibrations created at a first harmonic of the engine and the second vibration absorber is configured to absorb vibrations created at multiple harmonics of the engine.Type: ApplicationFiled: January 14, 2011Publication date: August 11, 2011Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Shushan Bai, Paul G. Otanez, Vijay A. Neelakantan, Donald L. Dusenberry
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Publication number: 20110186399Abstract: A dual clutch assembly includes a housing, an actuation member rotationally coupled with the housing, a first member coaxial with the housing, and a second member coaxial with the first member. A first clutch includes a first plate connected with the actuation member and a second plate connected for common rotation with the first member. A second clutch includes a first plate connected with the housing and a second plate connected for common rotation with the second member. At least one first lever is pivotally coupled to the housing. The first lever is pivotable to contact the actuation member thereby translating the actuation member and the first plate towards the second plate in order to engage the first clutch. The second lever is pivotable to contact the first plate of the second clutch and translate the first plate towards the second plate in order to engage the second clutch.Type: ApplicationFiled: January 29, 2010Publication date: August 4, 2011Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventors: Shushan Bai, Clinton E. Carey, Vijay A. Neelakantan, James M. Hart, Leonid Basin
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Publication number: 20110186395Abstract: A centrifugal pendulum vibration absorber (CPVA) for absorbing torsional vibration created by operation of an engine includes a plurality of pendulums moveable with respect to a rotatable shaft. The pendulums are connected to the rotatable shaft by a plurality of pins that extend through apertures in the pendulum. The pendulums each move along a path defined by various drive line or powertrain parameters and characteristics. The path is implemented by contouring an active section of the apertures that engage the pins.Type: ApplicationFiled: December 9, 2010Publication date: August 4, 2011Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Shushan Bai, Paul G. Otanez, Vijay A. Neelakantan
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Publication number: 20110180358Abstract: A system for absorbing vibration in a rotary member having a predetermined rotary speed of the present invention has a selectively moveable mass and a positioning mechanism. The mass is in communication with the rotary member having a predetermined position. The positioning mechanism exerts a force on the mass at least when the rotary member operates below the predetermined rotary speed. The force exerted by the positioning mechanism orients the mass at the predetermined position when the rotary member operates below the predetermined rotary speed.Type: ApplicationFiled: January 27, 2010Publication date: July 28, 2011Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventors: Paul G. Otanez, Shushan Bai, Vijay A. Neelakantan
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Publication number: 20110107864Abstract: An assembly for actuating a synchronizer includes a shift fork, a shift rail, and a permanent magnet connected to the shift rail. A first control coil is disposed in proximity to the permanent magnet. The first control coil is operable to produce a magnetomotive force on the permanent magnet in a first direction when a current is applied to the first control coil. A second control coil is disposed in proximity to the permanent magnet. The second control coil is operable to produce a magnetomotive force on the permanent magnet in a second direction when a current is applied to the second control coil. The permanent magnet is moved to a first position when the current is applied to the first control coil and the permanent magnet is moved to a second position when the current is applied to the second control coil. Movement of the magnet in turn moves the synchronizer between engaged positions.Type: ApplicationFiled: November 9, 2009Publication date: May 12, 2011Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventors: Shushan Bai, Vijay A. Neelakantan, Paul G. Otanez
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Publication number: 20110112737Abstract: A method of detecting substantial filling of a hydraulic cylinder of a hydraulically operated clutch of a vehicular transmission is disclosed and claimed. A pressure sensor disposed in a hydraulic line to the clutch cylinder provides a signal that the hydraulic pressure has dropped as the clutch cylinder begins to fill and also that the pressure has returned to a substantially normal level. The pressure sensor may be a continuously variable output such as an analog sensor, pulse width modulation (PWM) sensor, a similar device or, less desirably, a two state sensor. An iterative algorithm utilizes data from the sensor and a timer to determine when clutch fill is substantially complete.Type: ApplicationFiled: November 11, 2009Publication date: May 12, 2011Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventors: Vijay A. Neelakantan, Bret M. Olson
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Publication number: 20110100144Abstract: A shift mechanism for a dual clutch transmission employs a rotating barrel cam having at least three tracks which are engaged by and translate at least three associated cam followers. The cam followers extend from shift fork bodies which slide on rails and include shift forks which bi-directionally translate at least three synchronizer clutches which engage at least five forward gears or speeds and reverse. A single electric motor and gear train drive the barrel cam.Type: ApplicationFiled: November 4, 2009Publication date: May 5, 2011Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventors: Vijay A. Neelakantan, Bret M. Olson, Jesse B. Bradley, Ajit S. Grewal
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Publication number: 20110093172Abstract: A control system for a dual clutch transmission (DCT) of a vehicle comprises a difference module, a summer module, and a position control module. The difference module determines a difference between a desired position for a gear actuator and a measurement of a current position of the gear actuator. The summer module determines a sum of a derivative of the difference and a product of the difference and a predetermined gain. The position control module controls the current position of the gear actuator based on the sum. The current position of the gear actuator controls a position of a gear synchronizer that slides along an output shaft of the DCT. The position of the gear synchronizer controls coupling of a gear ratio with the output shaft.Type: ApplicationFiled: October 15, 2009Publication date: April 21, 2011Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventors: Yue-Ming Chen, Vijay A. Neelakantan
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Patent number: 7891261Abstract: A clutch actuation system for engaging and disengaging a clutch includes a hydraulically-actuated piston movable in response to hydraulic pressure to an apply position in which the piston is operable to engage the clutch. An electro mechanical actuator is movable in response to electric power to contact the piston at the apply position such that the clutch is maintained in an engaged state by the actuator, thereby permitting hydraulic pressure to be released. A method of controlling engagement of the clutch is also provided.Type: GrantFiled: August 16, 2007Date of Patent: February 22, 2011Assignee: GM Global Technology Operations LLCInventor: Vijay A. Neelakantan
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Publication number: 20100326542Abstract: A hydraulic control system for a automatic transmission includes a plurality of solenoids and valves in fluid communication with a plurality of shift actuators. The shift actuators are operable to actuate a plurality of torque transmitting devices. Selective activation of combinations of the solenoids allows for a pressurized fluid to activate at least one of the shift actuators. The solenoids are configured to provide a forward gear ratio and a reverse gear ratio when the solenoids are deengerized.Type: ApplicationFiled: June 25, 2009Publication date: December 30, 2010Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventors: Zhe Xie, Bret M. Olson, Robert L. Moses, Vijay A. Neelakantan
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Publication number: 20100304927Abstract: An automatic transmission includes a control system for controlling a clutch of the transmission. The control system includes a first variable flow solenoid and a second variable flow solenoid, each in selective fluid communication with the clutch. The first variable force solenoid provides hydraulic fluid within a first pressure range of 0 and 1,000 kPa. The second variable force solenoid provides hydraulic fluid within a second pressure range of 0 and 2,000 kPa. A transmission controller sends an electrical signal having a current between the range of 0 and 1 amp to one of the first and second variable flow solenoids. The pressure output of each of the first and second variable force solenoids is a function of, within their respective first and second pressure ranges, the amplitude of the current of the electrical signal to provide two distinct power gains to the single clutch.Type: ApplicationFiled: May 29, 2009Publication date: December 2, 2010Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventors: Vijay A. Neelakantan, Todd C. Schanz, Robert L. Moses, Bret M. Olson
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Publication number: 20100087999Abstract: An improved method and apparatus for detecting end-of-fill at a hydraulic clutch in an automatic transmission with a variable force solenoid are provided. The method includes: initiating clutch fill mode by commanding a high current to the solenoid whereby a high fluid pressure is delivered to the clutch apply volume; monitoring clutch fill time; determining if the fill time is greater than a threshold fill time; monitoring the current (e.g., actual and filtered) being actively drawn by the solenoid during clutch fill mode in response to the fill time being greater than the threshold fill time; detecting if an aberration occurs in the current; and stopping distribution of fluid to the hydraulic clutch in response to the current aberration. Detecting if an aberration occurs preferably includes determining a change in instantaneous armature velocity, and determining if the change in instantaneous velocity is greater than a threshold change in armature velocity.Type: ApplicationFiled: October 3, 2008Publication date: April 8, 2010Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventors: Vijay A. Neelakantan, Shushan Bai
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Publication number: 20100071357Abstract: An auxiliary pump system for a hybrid powertrain includes a hydraulic accumulator, a hydraulic transformer, a plurality of control devices, a sump, and a plurality of fluid flow paths. The accumulator is charged by a high flow, high pressure hydraulic fluid by opening a first of the control devices and closing a second of the control devices. The accumulator is discharged by closing the first of the control devices and opening the second of the control devices. A high pressure, low flow hydraulic fluid is communicated from the accumulator to the hydraulic transformer. The hydraulic transformer converts the high pressure, low flow hydraulic fluid into a high flow, low pressure hydraulic fluid that is employed by systems within the hybrid powertrain.Type: ApplicationFiled: August 28, 2009Publication date: March 25, 2010Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventors: Philip C. Lundberg, John C. Schultz, Vijay A. Neelakantan
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Publication number: 20100018829Abstract: A hydraulic control system for actuating a torque transmitting device in a transmission includes a sump for receiving a hydraulic fluid and a piezoelectric pump for pumping the hydraulic fluid from the sump to the torque transmitting device. A first fluid flow path communicates the hydraulic fluid from the sump to the piezoelectric pump and a second fluid flow path communicates the hydraulic fluid from the piezoelectric pump to the torque transmitting device. An exhaust means selectively communicates the hydraulic fluid from the torque transmitting device to the sump.Type: ApplicationFiled: July 25, 2008Publication date: January 28, 2010Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventors: Vijay A. Neelakantan, John C. Schultz, Bret M. Olson, Hamid Vahabzadeh, Robert L. Moses
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Publication number: 20090311116Abstract: A piezoelectric pump for pumping a fluid at a high flow rate includes a housing and an actuator located within the housing. An electric voltage applied to the actuator causes the actuator to apply a force to a first diaphragm that is proximate to the actuator. A piston assembly is located within the housing and is moveable between at least a first position and a second position. A first fluid chamber is defined by the housing, the first diaphragm, and the piston assembly. A coupling fluid is located within the first fluid chamber for coupling the first diaphragm to the piston assembly. A second fluid chamber is defined by the housing and the piston assembly. An inlet valve is in communication with the second fluid chamber and an outlet valve is in communication with the second fluid chamber.Type: ApplicationFiled: June 16, 2008Publication date: December 17, 2009Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventors: Shushan Bai, John C. Schultz, Vijay A. Neelakantan
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Publication number: 20090045028Abstract: A clutch actuation system for engaging and disengaging a clutch includes a hydraulically-actuated piston movable in response to hydraulic pressure to an apply position in which the piston is operable to engage the clutch. An electro mechanical actuator is movable in response to electric power to contact the piston at the apply position such that the clutch is maintained in an engaged state by the actuator, thereby permitting hydraulic pressure to be released. A method of controlling engagement of the clutch is also provided.Type: ApplicationFiled: August 16, 2007Publication date: February 19, 2009Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventor: Vijay A. Neelakantan
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Patent number: 6830141Abstract: A friction-based clutch actuation system includes a rotatable input shaft, an output shaft, at least one input clutch plate operatively supported by the input shaft, and at least one output clutch plate operatively supported by the output shaft and moveable thereon. The friction-based clutch actuation system also includes at least one electric motor and at least one piezoelectric actuator operatively connected to the at least one electric motor. The friction-based clutch actuation system further includes a controller electrically connected to the at least one electric motor and the at least one piezoelectric actuator to activate said at least one electric motor to move the piezoelectric actuator relative to the at least one output clutch plate and to activate the piezoelectric actuator to apply a force to the at least one output clutch plate to engage the at least one input clutch plate.Type: GrantFiled: May 23, 2003Date of Patent: December 14, 2004Assignee: General Motors CorporationInventors: Vijay A. Neelakantan, Norman Kenneth Bucknor