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US 8,708,342 B1Granted
Pneumatically controlled dual mode face seal
AssigneeBAE Systems Information and Electronic Systems Integration Inc.
InventorPhilip M Johnson
Life of this patent
Estimating the term…
Abstract
A pneumatically controlled, two part, rotational face seal is disclosed that has dual modes of operation. There is a first, static mode where a face of each of the two parts of the seal touch each other and provide an air, liquid and water vapor tight, very low leakage rate with high rotational friction between the two parts of the seal. In the second, dynamic mode wherein the two parts of the seal are separated by inert gas and the face seal functions as a gas bearing having very low rotational friction as the two parts are rotated with respect to each other. One part of the seal may be attached to a rotatable turret and the other part may be attached to a base on which the turret is mounted.
Claims18
A pneumatically controlled dual mode face seal having a first mode and a second mode, the face seal comprising:
- a first, flat plate having a first face and a second face, and having at least one groove in the first face, and there is a first hole through the first plate from its second face to the at least one groove in its first face, and there is a second hole through the first plate from its second face to the at least one groove in its first face;
- a second, flat plate having a first face and a second face;
- wherein in the first mode of the dual modes the first face of the first plate touches the first face of the second plate to create a high friction between the first and second flat plates that inhibits movement of the first plate and the second plate with respect to each other and creates a gas and liquid tight seal between the first plate and second plate,
- wherein in the second mode of the dual modes the first face of the first plate does not touch the first face of the second plate and the first flat plate and the second flat plate have no friction with respect to each other that inhibits movement of the first plate and the second plate with respect to each other,
- wherein to change the first and second plates from the first mode to the second mode gas at a first pressure is applied via the first hole to the at least one groove in the first face of the first plate to separate the first plate and second plate and create a gas bearing there between that permits the first and second plates to be easily moved with respect to each other, and
- wherein after the first plate and second plate are separated, gas at a second pressure that is lower than the first pressure is applied via the second hole to the at least one groove in the first face of the first plate to maintain the face seal in the second mode, and when it is desired to return the first and second flat plates to the first mode where they touch each other and create a gas and liquid tight seal the gas at the second pressure is terminated.
3 more elements
A pneumatically controlled, rotational, dual mode face seal having a first mode and a second mode, the face seal comprising:
- a first, flat plate having a first face and a second face, and having at least one groove in the first face and there is at least one hole through the first plate from its second face to the at least one groove in its first face;
- and
- a second, flat plate having a first face and a second face;
- wherein in the first mode of the dual modes the first face of the first plate touches the first face of the second plate to create a high friction between the two plates that inhibits rotation of the two plates with respect to each other,
- wherein in the second mode of the dual modes there is a gas bearing created between the first face of the first plate and the first face of the second plate and there is little or no friction inhibiting rotation of the two plates with respect to each other, and
- wherein to change the first and second plates from the first mode to the second mode gas at a first pressure is applied to the at least one groove in the first face of the first plate to separate the first and second plates, and to maintain the separation between the first plate and the second plate, gas at a second pressure is applied via the at least one hole to the at least one groove in the first face of the first plate, and while the first and second flat plates are in the second mode the gas at the second pressure creates the gas bearing that permits the first and second plates to be easily rotated with respect to each other, and when such rotation has been accomplished the gas at a second pressure is terminated and the first and second flat plates return to the first mode where the first plate and the second plate touch each other.
3 more elements
A pneumatically controlled dual mode face seal having a first mode and a second mode, the face seal comprising:
- a first, flat plate having a first face and a second face, having a plurality of grooves in the first face, and having a plurality of first holes through the first plate from its second face to its first face with at least one first hole to each of the plurality of grooves in the first face, and having a plurality of second holes through the first plate from its second face to its first face with at least one second hole to each of the plurality of grooves in the first face;
- a second, flat plate having a first face and a second face;
- wherein in the first mode of the dual modes the first face of the first plate touches the first face of the second plate to create a high friction between the first and second flat plates that inhibits movement of the first plate and the second plate with respect to each other and creates a gas and liquid tight seal between the first plate and second plate,
- wherein in the second mode of the dual modes the first face of the first plate does not touch the first face of the second plate and the first flat plate and the second flat plate have no friction with respect to each other that inhibits movement of the first plate and the second plate with respect to each other,
- wherein to change the first and second plates from the first mode to the second mode gas at a first pressure is applied via each of the first holes to each of the plurality of grooves in the first face of the first plate to separate the first plate from the second plate and create a gas bearing there between that permits the first and second plates to be easily moved with respect to each other, and
- wherein after the first plate and second plate are separated, gas at a second pressure that is lower than the first pressure is applied via each of the plurality of second holes to each of the plurality of grooves in the first face of the first plate to maintain the face seal in the second mode, and when it is desired to return the first and second plates to the first mode where they touch each other and create a gas and liquid tight seal the gas at the second pressure is terminated.
3 more elements
Dependencies are inferred from the claim text.