Mark P Krefta

6952086, Oct 4, 2005

Oct 10, 2003

10/683964

Mark Peter Krefta - Murrysville PA, US
David Jonathan Hall - Pittsburgh PA, US
Kenneth Martin Eichler - Murrysville PA, US
Jiing-Liang Wu - Murrysville PA, US
Robert E. Strickler - Pittsburgh PA, US
Michael Barnaby Brennen - Pittsburgh PA, US

Curtiss-Wright Electro-Mechanical Corporation - Cheswick PA

H02K041/00

318135, 310 12

A control system for a linear motor adapted to accurately supply a moving window of power to the stator coils. A plurality of individually switched stator coils run the length of a linear motor to move a rotor down the long axis of the stator. Accurate inductive-based position sensors continuously provide position data for the moving rotor. A processing unit calculates a proper time delay from a source voltage peak in order to apply power to the next stator coil in the moving direction of the rotor such that no DC offshoot/undershoot occurs. The linear motor control system optionally includes a failure prevention switching scheme in which pairs of individual stator coils on opposite sides of a double-sided stator are switched together.

8076881, Dec 13, 2011

Jun 16, 2009

12/485788

David J. Hall - Pittsburgh PA, US
Mark P. Krefta - Murrysville PA, US

Curtiss-Wright Electro-Mechanical Corp. - Chewick PA

H02P 31/00
H02P 1/46

3184002, 31840032, 31840033, 318701, 318802

A system. The system includes a first module, a second module communicably connected to the first module, a third module communicably connected to the first module, and a fourth module communicably connected to the third module. The first module is configured for determining an angle. The angle is defined by a first rotating reference frame having an axis aligned with a permanent magnet flux of a permanent magnet motor, and a vector of a motor magnetizing flux of the permanent magnet motor. The second module is configured for defining a second rotating reference frame having an axis aligned with the vector, and for transforming a two-phase set of direct currents from the first rotating reference frame to the second rotating reference frame. The first and second rotating reference frames are synchronized. The third module is configured for generating a first direct current reference signal associated with the second rotating reference frame.

20040150283, Aug 5, 2004

Jan 31, 2003

10/356261

Raymond Calfo - Murrysville PA, US
Mark Krefta - Murrysville PA, US

H02K021/12

310/156550

A permanent magnet synchronous machine with improved torque and power characteristics. A circumferential-oriented rotor assembly is provided with alternating permanent magnets and magnetic pole pieces. In order to reduce the amount of leakage flux in the rotor and increase the effective length of the permanent magnet, a trapezoidal or otherwise tapered permanent magnet structure is used. By alternating trapezoidal permanent magnet, and magnetic pole pieces, a higher intensity magnetic field is created in the air gap utilizing the same radial space in the motor without altering the weight or volume of the motor compared to conventional machines.

20130069568, Mar 21, 2013

Sep 15, 2011

13/233055

Mark P. KREFTA - Murrysville PA, US
Kalyan K. SEN - Monroeville PA, US

Curtiss-Wright Electro-Mechanical Corporation - Cheswick PA

H02P 21/00

31840002

A system. The system includes a processor, a first module, a second module and a third module. The first module is communicably connected to the processor and is configured for calculating a q-axis voltage component and a d-axis voltage component. The second module is communicably connected to the processor and is configured for determining a voltage angle relative to the q-axis. The third module is communicably connected to the processor and is configured for (1) comparing the determined voltage angle to a predetermined value, (2) outputting the determined voltage angle if the determined voltage angle is less than the predetermined value, and (3) outputting the predetermined value if the predetermined value is less than the determined voltage angle.