Patents by Inventor Khwaja Rahman
Khwaja Rahman 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: 11824413Abstract: A winding arrangement for a stator of an electric motor includes winding hairpins arranged to form one or more phases. The stator includes a plurality of motor teeth forming a plurality of slots each configured to accommodate multiple layers. A first set of winding hairpins spanning of M slots are coupled in series and coupled to a phase lead, and are arranged sequentially in a first azimuthal direction. A jumper is arranged in a layer and is coupled in series with the first set of winding hairpins. A second set of winding hairpins configured to span of M slots are coupled in series between the jumper and a neutral lead. The second set of winding hairpins are arranged sequentially in the opposite azimuthal direction, and along with the first set of winding hairpins and the jumper, form a continuous electrical path between the phase lead and the neutral lead.Type: GrantFiled: July 7, 2021Date of Patent: November 21, 2023Assignee: Rivian IP Holdings, LLCInventors: Khwaja Rahman, Dang Dinh Dang
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Patent number: 11766943Abstract: A drive system includes a first drive train and a second drive train coupled by a differential assembly. Each drive train include a motor, an output gear, and a clutch assembly that engages and disengages the output gear from respective halfshafts. The differential assembly is configured to couple the first and second halfshafts, and connect/disconnect the first output gear and the first halfshaft. The differential assembly includes, for example, side gears, a spider gearset, and an actuator for engaging and disengaging the differential casing from the first output gear. A control system is configured to actuate actuators of clutch assemblies and/or a differential assembly to achieve one or more drive modes for each drive axis. The control system determines the first drive mode, controls the clutch assemblies and differential assemblies, and controls one or more motors. The drive modes include, for example, torque vectoring, fully locked, single motor, and neutral.Type: GrantFiled: November 10, 2022Date of Patent: September 26, 2023Assignee: RIVIAN IP HOLDINGS, LLCInventors: Mason Verbridge, Cameron P. Williams, Khwaja Rahman, Henry Huang, Vinaey Kalyanaraman
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Publication number: 20230275482Abstract: A motor stator for a motor is disclosed. The motor stator includes a stator body and a plurality of windings. The stator body includes a weld end, a crown end, and a plurality of slots arranged circumferentially and extending axially therethrough between the weld end and the crown end, the slots including a plurality of layers arranged in a radial direction with layers being organized in conductor pairs. Each winding includes a plurality of coils and a plurality of weld pairs. Each weld pair includes legs of two respective coils joined together to form an electrical connection between the two respective coils. The plurality of weld pairs includes one or more jumper weld pairs arranged to jump the respective winding between two respective conductor pairs.Type: ApplicationFiled: February 25, 2022Publication date: August 31, 2023Inventors: Logan Noel Balliett, Dang Dinh Dang, Khwaja Rahman
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Publication number: 20230077890Abstract: A drive system includes a first drive train and a second drive train coupled by a differential assembly. Each drive train include a motor, an output gear, and a clutch assembly that engages and disengages the output gear from respective halfshafts. The differential assembly is configured to couple the first and second halfshafts, and connect/disconnect the first output gear and the first halfshaft. The differential assembly includes, for example, side gears, a spider gearset, and an actuator for engaging and disengaging the differential casing from the first output gear. A control system is configured to actuate actuators of clutch assemblies and/or a differential assembly to achieve one or more drive modes for each drive axis. The control system determines the first drive mode, controls the clutch assemblies and differential assemblies, and controls one or more motors. The drive modes include, for example, torque vectoring, fully locked, single motor, and neutral.Type: ApplicationFiled: November 10, 2022Publication date: March 16, 2023Inventors: Mason Verbridge, Cameron P. Williams, Khwaja Rahman, Henry Huang, Vinaey Kalyanaraman
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Publication number: 20230018571Abstract: A winding arrangement for a stator of an electric motor includes winding hairpins arranged to form one or more phases. The stator includes a plurality of motor teeth forming a plurality of slots each configured to accommodate multiple layers. A first set of winding hairpins spanning of M slots are coupled in series and coupled to a phase lead, and are arranged sequentially in a first azimuthal direction. A jumper is arranged in a layer and is coupled in series with the first set of winding hairpins. A second set of winding hairpins configured to span of M slots are coupled in series between the jumper and a neutral lead. The second set of winding hairpins are arranged sequentially in the opposite azimuthal direction, and along with the first set of winding hairpins and the jumper, form a continuous electrical path between the phase lead and the neutral lead.Type: ApplicationFiled: July 7, 2021Publication date: January 19, 2023Inventors: Khwaja Rahman, Dang Dinh Dang
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Patent number: 11498431Abstract: A drive system includes a first drive train and a second drive train coupled by a differential assembly. Each drive train include a motor, an output gear, and a clutch assembly that engages and disengages the output gear from respective halfshafts. The differential assembly is configured to couple the first and second halfshafts, and connect/disconnect the first output gear and the first halfshaft. The differential assembly includes, for example, side gears, a spider gearset, and an actuator for engaging and disengaging the differential casing from the first output gear. A control system is configured to actuate actuators of clutch assemblies and/or a differential assembly to achieve one or more drive modes for each drive axis. The control system determines the first drive mode, controls the clutch assemblies and differential assemblies, and controls one or more motors. The drive modes include, for example, torque vectoring, fully locked, single motor, and neutral.Type: GrantFiled: July 26, 2021Date of Patent: November 15, 2022Assignee: Rivian IP Holdings, LLCInventors: Mason Verbridge, Cameron P. Williams, Khwaja Rahman, Henry Huang, Vinaey Kalyanaraman
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Publication number: 20080061525Abstract: A vehicular wheel assembly includes a first bearing component configured to be coupled to a frame of a vehicle, a second bearing component rotatably coupled to the first bearing component, and a brake mechanism coupled to the second bearing component. The motor includes a stator and a rotor. The stator is coupled to the first bearing component and the rotor is coupled to the second bearing component such that rotation of the rotor relative to the stator causes the second bearing component to rotate relative to the first bearing component. The brake mechanism is between the motor and the frame and is configured to slow the rotation of the second bearing component and the rotor.Type: ApplicationFiled: September 7, 2007Publication date: March 13, 2008Applicant: GM GLOBAL TECHNOLOGY OPERATIONS, INC.Inventors: Terence Ward, James Nagashima, Michael Milani, Khwaja Rahman
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Publication number: 20080030155Abstract: Methods and apparatus are provided for an electric vehicle embodying an axial flux traction motor directly coupled to a wheel thereof. The traction motor comprises a stator having coils for producing a magnetic field, an annular rotor magnetically coupled to the stator and mechanically to an output shaft. Permanent magnets of alternating polarity are mounted on the annular rotor. Magnetic shunts bridge a portion of the stator slots above the coils. The magnets are arranged in groups with group-to-group spacing exceeding magnet-to-magnet spacing. Adjacent edges of the magnets diverge. The method comprises, looking up d- and q-axis currents to provide the requested torque and motor speed for the available DC voltage, combining at least one of the d- and q-axis currents with a field weakening correction term, converting the result from synchronous to stationary frame and operating an inverter therewith to provide current to the coils of the motor.Type: ApplicationFiled: August 27, 2007Publication date: February 7, 2008Inventors: Nitinkumar Patel, Silva Hiti, Khwaja Rahman
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Publication number: 20060284582Abstract: A system and method for controlling an IPM synchronous machine in a vehicle that calculates an operating trajectory of the machine on-line. The system defines three operating ranges of the machine based on voltage magnitude, where a first operating range is controlled by a current limit of the machine and second and third operating regions are controlled by a voltage limit of the machine. The system calculates d- and q-axis current reference signals in the reference rotor frame for each of the three regions. The system determines which set of current reference signals will be used to control the machine based on the operating region. The third operating region is used during over-modulation of the machine.Type: ApplicationFiled: June 17, 2005Publication date: December 21, 2006Inventors: Yu-Seok Jeong, Seung Sul, Silva Hiti, Khwaja Rahman, Bon-Ho Bae
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Patent number: 7061134Abstract: The present invention includes a method for thermal management in a voltage source inverter. The method includes sensing a low output frequency condition, determining a zero vector modulation responsive to the sensed low output frequency condition, and applying the determined zero vector modulation to reduce thermal stress in the voltage source inverter. The step of determining the zero vector modulation responsive to the sensed low output frequency condition includes mapping an output voltage requirement to a space vector structure and determining state switching space vectors based on the mapped output voltage requirement.Type: GrantFiled: August 1, 2003Date of Patent: June 13, 2006Assignee: General Motors CorporationInventors: Silva Hiti, Constantin C. Stancu, Khwaja Rahman, Scott D. Downer, James M. Nagashima, Eric R. Ostrom
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Publication number: 20060097702Abstract: A method of controlling an IPM machine having a salient rotor. Stator terminal signals are measured and rotated to obtain synchronous reference frame current signals. A rotor position is estimated based on an impedance generated using the rotor and included in the current signals. The estimated rotor position is used to control the machine. An alternator-starter system in which this method is used can provide high cranking torque and generation power over a wide speed range while providing operational efficiency.Type: ApplicationFiled: November 9, 2004Publication date: May 11, 2006Inventors: James Nagashima, Khwaja Rahman, Nitinkumar Patel, Steven Schulz, Terence Ward, Stanley Fujii
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Publication number: 20050275302Abstract: A machine includes a stator and a rotor having a plurality of poles. Each pole is formed at least in part by a plurality of permanent magnets recessed within the rotor at a predetermined distance from an outer surface of the rotor. The distance is predetermined to minimize rotor flux variation near the outer surface during rotation of the rotor relative to the stator. Eddy current losses are thereby reduced.Type: ApplicationFiled: June 14, 2004Publication date: December 15, 2005Inventors: Khwaja Rahman, James Nagashima
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Publication number: 20050231152Abstract: A hybrid/electric vehicle including a battery system connected to a DC charger, an inverter coupled to the battery system, and an electric AC motor coupled to the inverter. The motor has first, second and third stator windings corresponding to first, second and third phases of the motor. Each stator winding has first and second leads, and the inverter has a plurality of switches that are connected to provide current to the stator windings at the first and second leads.Type: ApplicationFiled: April 19, 2004Publication date: October 20, 2005Inventors: Brian Welchko, James Nagashima, Khwaja Rahman
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Publication number: 20050035678Abstract: Methods and apparatus are provided for an axial electric motor. The apparatus comprises, a stator having coils thereon for producing a magnetic field, a rotor rotated by the magnetic field, and an output shaft coupled to the rotor. The rotor includes a magnetic and non-magnetic component. The non-magnetic component has a lower density than the magnetic component. One or both of the rotor components have apertures therein for ventilation and weight reduction. Permanent magnets are desirably mounted on the magnetic component of the rotor facing the stator and portions of the rotor behind the permanent magnets are hollowed out to be thinner than portions of the rotor between the permanent magnets. This reduces rotor weight without significantly affecting magnetic flux density in the rotor or motor torque.Type: ApplicationFiled: July 29, 2004Publication date: February 17, 2005Inventors: Terence Ward, Khwaja Rahman, James Nagashima, Fabio Crescimbini, Federico Caricchi, Giorgio Lucchi
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Publication number: 20050035672Abstract: Methods and apparatus are provided for an axial electric motor. The apparatus comprises, a stator having coils thereon for producing a magnetic field, a rotor rotated by the magnetic field, an output shaft coupled to the rotor, and a ring incorporating a coolant channel circumferentially engaging the stator for absorbing heat and reaction torque from the stator. It is preferable that that the ring have inwardly extending teeth that mesh with the coils on the stator. The space between the teeth and the coils is preferably filled with a substantially solid thermally conductive material to transmit stator reaction torque to the teeth and cool the stator. The coils are preferably formed from a flat ribbon a portion of whose principal surface is perpendicular to the teeth. A supporting frame is desirably fixedly coupled to the ring and rotatably coupled to the output shaft.Type: ApplicationFiled: July 29, 2004Publication date: February 17, 2005Inventors: Terence Ward, Khwaja Rahman, James Nagashima, Fabio Crescimbini, Federico Caricchi, Giorgio Lucchi
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Publication number: 20050035676Abstract: Methods and apparatus are provided for an electric vehicle embodying an axial flux traction motor directly coupled to a wheel thereof. The traction motor comprises a stator having coils for producing a magnetic field, an annular rotor magnetically coupled to the stator and mechanically to an output shaft. Permanent magnets of alternating polarity are mounted on the annular rotor. Magnetic shunts bridge a portion of the stator slots above the coils. The magnets are arranged in groups with group-to-group spacing exceeding magnet-to-magnet spacing. Adjacent edges of the magnets diverge. The method comprises, looking up d- and q-axis currents to provide the requested torque and motor speed for the available DC voltage, combining at least one of the d- and q-axis currents with a field weakening correction term, converting the result from synchronous to stationary frame and operating an inverter therewith to provide current to the coils of the motor.Type: ApplicationFiled: July 29, 2004Publication date: February 17, 2005Inventors: Khwaja Rahman, Silva Hiti, Nitinkumar Patel, Terence Ward, James Nagashima, Fabio Crescimbini, Federico Caricchi
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Publication number: 20050024902Abstract: The present invention includes a method for thermal management in a voltage source inverter. The method includes sensing a low output frequency condition, determining a zero vector modulation responsive to the sensed low output frequency condition, and applying the determined zero vector modulation to reduce thermal stress in the voltage source inverter. The step of determining the zero vector modulation responsive to the sensed low output frequency condition includes mapping an output voltage requirement to a space vector structure and determining state switching space vectors based on the mapped output voltage requirement.Type: ApplicationFiled: August 1, 2003Publication date: February 3, 2005Inventors: Silva Hiti, Constantin Stancu, Khwaja Rahman, Scott Downer, James Nagashima, Eric Ostrom