Air turbine starter with lubrication recirculation circuit
An air turbine starter (ATS) for a gas turbine engine having an accessory gear box (AGB) with a lubricant reservoir, the air turbine starter comprising a housing at least partially defining a working air flow path; a turbine section comprising a turbine having an output shaft and a plurality of blades circumferential spaced about the output shaft and at least partially extending into the working air flow path; a drive section having a drive shaft operably coupled to the output shaft to engage the AGB; and a lubrication recirculation circuit fluidly coupled to the lubricant reservoir.
1. A lubrication recirculation circuit comprising:
a housing;
a distribution chamber provided within the housing;
a piston disposed within the distribution chamber, the piston movable between a first piston position and a second piston position;
a stopper movably disposed within the piston and having at least one outlet;
a reservoir fluidly coupled to the distribution chamber; and a lubrication line fluidly coupling the reservoir to the distribution chamber, the lubrication line further comprising a first conduit and a second conduit each extending from the distribution chamber;
wherein the first conduit of the lubrication line is open to a flow of lubricant when the piston is in the first piston position, and wherein the second conduit of the lubrication line is open to a flow of lubricant when the piston is in the second piston position; and
wherein the stopper includes a hollow portion which allows the lubricant to flow through an interior of the stopper.
2. The lubrication recirculation circuit of claim 1 , further comprising a pressure valve provided within the distribution chamber, the pressure valve including a valve housing, and wherein the piston and the stopper are positioned within the valve housing.
3. The lubrication recirculation circuit of claim 2 , wherein the valve housing further includes a closed end spaced from an open end, with the open end fluidly coupling the distribution chamber to the reservoir.
4. The lubrication recirculation circuit of claim 2 , further comprising a set of openings provided in the valve housing.
5. The lubrication recirculation circuit of claim 4 , wherein the set of openings further comprise a first opening fluidly coupling the first conduit to the distribution chamber when the piston is in the first piston position, and a second opening fluidly coupling the second conduit to the distribution chamber when the piston is in the second piston position.
6. The lubrication recirculation circuit of claim 5 , wherein the piston further comprises a first piston wall defining a piston interior.
7. The lubrication recirculation circuit of claim 6 , further comprising a set of thru holes extending through the first piston wall.
8. The lubrication recirculation circuit of claim 7 , wherein the set of thru holes further includes a first thru hole fluidly coupling the piston interior to the first conduit through the first opening in the valve housing when the piston is in the first piston position, and wherein the set of thru holes further includes a second thru hole fluidly coupling the piston interior to the second conduit through the second opening in the valve housing when the piston is in the second piston position.
9. The lubrication recirculation circuit of claim 6 , further comprising a second piston wall extending into the piston interior perpendicular to the first piston wall and at least partially dividing the piston interior into a first chamber and a second chamber.
10. The lubrication recirculation circuit of claim 9 , further comprising a first spring positioned within the first chamber and a second spring positioned within the second chamber.
11. The lubrication recirculation circuit of claim 10 , wherein the first spring has a different spring constant than the second spring.
12. The lubrication recirculation circuit of claim 10 , wherein the stopper further includes a nose extending interior of the first spring and the second spring.
13. The lubrication recirculation circuit of claim 10 , wherein the stopper is movable between a first stopper position, a second stopper position, and a third stopper position, and wherein a spring constant for the second spring enables the stopper to position at the third stopper position between the first stopper position and the second stopper position.
14. The lubrication recirculation circuit of claim 13 , further comprising a bypass line and a return line, and wherein the bypass line connects the lubrication line to the return line when the stopper is at the third stopper position.
15. The lubrication recirculation circuit of claim 1 , wherein the stopper defines the hollow portion extending between a first end and a second end.
16. The lubrication recirculation circuit of claim 15 , wherein the stopper further includes a first stopper outlet fluidly coupling the hollow portion to the first conduit when the piston is in the first piston position, and a second stopper outlet fluidly coupling the hollow portion to the second conduit when the piston is in the second piston position.
17. The lubrication recirculation circuit of claim 1 , wherein the stopper is movable between a first stopper position and a second stopper position when the piston moves between the first piston position and the second piston position, wherein the stopper positions at the first stopper position when the piston is in the first piston position, and wherein the stopper positions at the second stopper position when the piston is in the second piston position.
18. A lubrication recirculation circuit comprising:
a housing;
a distribution chamber provided within the housing;
a piston disposed within the distribution chamber and defining a piston interior, the piston movable between a first piston position and a second piston position;
a stopper disposed within the piston movable between a first stopper position when the piston moves to the first piston position and a second stopper position when the piston moves to the second piston position; and
a lubrication line including a first conduit and a second conduit each extending from the distribution chamber;
wherein the first conduit of the lubrication line is open to a flow of lubricant from the distribution chamber when the piston is in the first piston position, and wherein the second conduit of the lubrication line is open to a flow of lubricant when the piston is in the second piston position.
19. The lubrication recirculation circuit of claim 18 , wherein the piston further comprises a piston wall at least partially dividing the piston interior into a first chamber and a second chamber, and wherein a first spring is provided in the first chamber and a second spring is provided in the second chamber.
20. The lubrication recirculation circuit of claim 19 , wherein the stopper is further movable to a third stopper position, wherein a spring constant for the second spring enables the stopper to position at the third stopper position between the first stopper position and the second stopper position.