Normally-closed zero-leak valve with magnetostrictive actuator
AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration
InventorsDANIEL J. RAMSPACHER, JAMES A. RICHARD
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Abstract
A non-pyrotechnic, normally-closed, zero-leak valve is a replacement for the pyrovalve used for both in-space and launch vehicle applications. The valve utilizes a magnetostrictive alloy for actuation, rather than pyrotechnic charges. The alloy, such as Terfenol-D, experiences magnetostriction, i.e. a gross elongation, when exposed to a magnetic field. This elongation fractures a parent metal seal, allowing fluid flow through the valve. The required magnetic field is generated by redundant coils that are isolated from the working fluid.
Claims20
A zero-leak, normally-closed fluid valve having a central longitudinal axis, comprising:
- an actuator housing and a flow cavity housing, the flow cavity housing having a flow inlet and a flow outlet;
- an actuator column including an actuator rod disposed in the actuator housing, the actuator rod centered on the central longitudinal axis and made of a magnetostrictive material;
- a solenoid that surrounds the actuator rod and, when activated, creates magnetostriction in the actuator rod;
- a Belleville spring stack including a mandrel guide that is axially aligned with the actuator rod;
- a valve stem having a portion axially translatable in an opening in one end of the mandrel guide;
- a fracture plate axially aligned with and fixed to the valve stem, the fracture plate sealing the flow outlet in a normally-closed position of the fluid valve;
- a compression spring with a first end that bears on a surface of the actuator housing and a second end that bears on the valve stem to bias the valve stem towards the flow outlet;
- and
- a bellows that extends between the surface of the actuator housing and the valve stem and that seals the actuator housing from the flow cavity housing.
A zero-leak, normally-closed fluid valve having a central longitudinal axis, comprising:
- an actuator housing and a flow cavity housing, the flow cavity housing having a flow inlet and a flow outlet;
- an actuator column including an actuator rod disposed in the actuator housing, the actuator rod centered on the central longitudinal axis and made of Terfenol-D;
- a solenoid that surrounds the actuator rod and, when activated, creates magnetostriction in the actuator rod, the solenoid including primary coils and secondary coils that are redundant to the primary coils;
- a Belleville spring stack including a mandrel guide that is axially aligned with the actuator rod;
- a valve stem having a portion axially translatable in an opening in one end of the mandrel guide;
- a fracture plate axially aligned with and fixed to the valve stem, the fracture plate sealing the flow outlet in a normally-closed position of the fluid valve;
- a compression spring with a first end that bears on a surface of the actuator housing and a second end that bears on the valve stem to bias the valve stem towards the flow outlet;
- and
- a bellows that extends between the surface of the actuator housing and the valve stem and that seals the actuator housing from the flow cavity housing.
Dependencies are inferred from the claim text.