| WOODWARD HRT, INC. Patent applications |
| Patent application number | Title | Published |
|---|
| 20120112109 | DIRECT DRIVE SERVOVALVE HAVING REDUNDANT DRIVE MOTORS - A direct drive servovalve ( | 05-10-2012 |
| 20120091255 | SHIFT LOCK ASSEMBLY - A shift lock assembly includes a drive member carried by a drive shaft and configured to rotatably couple to a drive motor and a shift mechanism disposed between the drive member and a ground plate, the shift mechanism configured to move between a first position and a second position relative to the drive member and the ground plate. When disposed in the first position, the shift mechanism is configured to couple the drive shaft to the ground plate and decouple the drive shaft from the drive member to allow rotation of the drive member relative to the drive shaft. When disposed in the second position, the shift mechanism is configured to couple the drive shaft to the drive member and decouple the drive shaft from the ground plate to allow rotation of the drive shaft in response to rotation of the drive member. | 04-19-2012 |
| 20120090459 | FLOATING PISTON ACTUATOR FOR OPERATION WITH MULTIPLE HYDRAULIC SYSTEMS - A floating piston actuator for use with multiple hydraulic systems includes a housing and a piston assembly. The piston assembly includes an elongate shaft or ram, at least one secured piston coupled to the ram, and a set of moveable pistons moveably disposed within the housing chamber on the ram such that the set of moveable pistons are translatable relative to a longitudinal axis of the ram. The set of moveable pistons form at least three hydraulically separate actuator cylinders where each of the three hydraulically separate actuator cylinders are disposed in fluid communication with a corresponding pressurized fluid source. The floating piston actuator allows hydraulic redundancy while maintaining a similar length compared to existing multi-system actuators. The floating pistons can be arranged in multiple configurations to allow operation with a hydraulic system failure without force fight or binding and with a higher output force than conventional multi-system actuators. | 04-19-2012 |
| 20120068095 | TORQUE MOTOR LINEARIZATION - A servovalve torque motor includes first and second pole pieces and an armature. Each of the first and second pole pieces includes an armature face that opposes the armature. The area of the armature face of the second pole piece is smaller than the area of the armature face of the first pole piece. The unequal areas of the first and second armature faces create a bias in the servovalve torque motor while allowing the first and second pole pieces to be disposed at equal distances from the armature to define substantially equal air gaps. The inclusion of substantially equal air gaps between the pole pieces and the armature reduces the maximum flux in the armature for the same bias and torque output, compared to conventional servovalve torque motors. The reduction in maximum armature flux decreases armature saturation and improves linearity during operation. | 03-22-2012 |
| 20120001582 | CONTROLLER FOR ACTUATION SYSTEM EMPLOYING KALMAN ESTIMATOR INCORPORATING EFFECT OF SYSTEM STRUCTURAL STIFFNESS - A controller for an electro-mechanical actuation system such as a missile fin actuator includes a Kalman estimator circuit which generates an estimate of operating state including position and velocity of motor, position and velocity of a position-controlled element (PCE), and motor current. The estimate is generated based on a dynamic model explicitly including the effect of structural stiffness and damping in the coupling between the motor and the PCE, for example by treating it as a mechanical oscillator having spring and damping constants. The Kalman estimator operates on a motor drive control signal and a measured position signal which may be from a Hall sensor sensing motor position. A linear quadratic regulator circuit generates a control effort signal by applying a state feedback gain matrix to a state vector. The state feedback gain matrix minimizes a quadratic cost function representing variance of the control effort signal and/or the measured position signal. | 01-05-2012 |
