Drop-tight spool and sleeve for metering valve

Patent metadata

Field	Value
Publication number	US-10428743-B2
Application number	US-201715451788-A
Country	US
Kind code	B2
Filing date	Mar 7, 2017
Priority date	Mar 7, 2017
Publication date	Oct 1, 2019
Grant date	Oct 1, 2019

Abstract

A spool and sleeve assembly for a metering valve comprises a spool body defining a center axis, and a sleeve body having a bore that receives the spool body. The sleeve body includes at least one metering window open to the bore and is moveable between a metering position to control flow through the metering window and a shutoff position where flow is prevented from exiting an outlet end of the bore. A seal assembly reacts between the spool body and the sleeve body to provide at least a first sealing interface and a second sealing interface axially spaced from the first sealing interface when the spool body is in the shutoff position. A metering valve for a fuel system is also disclosed.

First claim

The invention claimed is:

1. A spool and sleeve assembly for a metering valve comprising:
a spool body extending between a first end portion and a second end portion to define a center axis, and wherein the spool body has an outermost diameter at a central portion between the first and second end portions and a first reduced diameter portion that is axially between the central portion and the second end portion of the spool body, and wherein the second end portion of the spool body has an increased diameter relative to the first reduced diameter portion;
a sleeve body having a bore that receives the spool body, the sleeve body including at least one metering window open to the bore, and wherein the spool body is moveable between a metering position to control flow through the metering window and a shutoff position where flow is prevented from exiting an outlet end of the bore, and wherein the first reduced diameter portion of the spool body at least partially overlaps with the at least one metering window when in the metering position; and
a seal assembly reacting between the spool body and the sleeve body to provide at least a first sealing interface associated with the first end portion of the spool body and a second sealing interface associated with the second end portion of the spool body and axially spaced from the first sealing interface when the spool body is in the shutoff position.

2. The spool and sleeve assembly according to claim 1 , wherein the spool body includes a second reduced diameter portion between the first end portion and the central portion that is defined by a diameter that is less than the outermost diameter at the central portion, and wherein the compliant seal assembly surrounds the second reduced diameter portion.

3. The spool and sleeve assembly according to claim 1 , wherein the bore includes a first seat for the first sealing interface and a second seat for the second sealing interface, and wherein the first seat comprises a linear shoulder portion that extends in a radially inward direction and includes a protruding portion that engages the compliant seal, and wherein the protruding portion transitions from the linear shoulder portion as a ramped surface that extends radially inward at an angle that extends in a direction toward the compliant seal, and wherein the spool body includes a first shoulder that exerts a seal reaction load at a radially inward portion of the compliant seal when in the shutoff position, and wherein the protruding portion exerts a pressure load against a radially outward portion of the compliant seal when in the shutoff position.

4. The spool and sleeve assembly according to claim 1 , wherein the first sealing interface comprises a compliant seal assembly and the second sealing interface comprises a direct contact interface.

5. The spool and sleeve assembly according to claim 4 , wherein the compliant seal assembly comprises at least a compliant seal and a rubber seal.

6. The spool and sleeve assembly according to claim 4 , wherein the second end portion terminates at a distal end gripping surface, and wherein the direct contact interface comprises direct contact between the distal end gripping surface of the spool body and an inner surface of the bore to form the second sealing interface.

7. The spool and sleeve assembly according to claim 6 , wherein the direct contact comprises metal-to-metal contact.

8. The spool and sleeve assembly according to claim 4 , wherein the bore includes a first seat for the first sealing interface and wherein the first seat includes a protruding portion that engages the compliant seal assembly.

9. The spool and sleeve assembly according to claim 8 , wherein the spool body includes a first shoulder that supports a radially inward portion of the compliant seal assembly and wherein the protruding portion exerts a pressure load against a radially outward portion of the compliant seal assembly when in the shutoff position.

10. The spool and sleeve assembly according to claim 8 , wherein the sleeve body includes a second seat for the second sealing interface, and wherein the spool body includes the second end portion that faces the outlet end of the bore, and wherein the second end portion terminates at a distal end gripping surface that directly engages the second seat when in the shutoff position.

11. The spool and sleeve assembly according to claim 10 , including a plunger coupled to the spool body for movement therewith and an actuator device that cooperates with the plunger to move the spool body between the metering and shutoff positions.

12. The spool and sleeve assembly according to claim 10 , wherein the metering window is configured to receive fuel from a gas turbine engine fuel supply, and wherein the first reduced diameter portion at least partially overlaps with the at least one metering window when in the metering position such that fuel can exit the outlet end of the bore when in the metering position.

13. A metering valve for a fuel system comprising:
a fuel pump drawing fuel from a fuel supply;
a metering valve receiving fuel from the fuel supply, and wherein fuel exiting the metering valve is directed to an engine, wherein the metering valve includes
a spool body extending between a first end portion and a second end portion to define a center axis, and wherein the spool body has an outermost diameter at a central portion between the first and second end portions and a first reduced diameter portion that is axially between the central portion and the second end portion of the spool body, and wherein the second end portion of the spool body has an increased diameter relative to the first reduced diameter portion
a sleeve body having a bore that receives the spool body, the sleeve body including at least one metering window open to the bore, and wherein the spool body is moveable between a metering position to control flow through the metering window and a shutoff position where flow is prevented from exiting an outlet end of the bore, and wherein the first reduced diameter portion of the spool body at least partially overlaps with the at least one metering window when in the metering position and
a seal assembly reacting between the spool body and the sleeve body to provide at least a first sealing interface associated with the first end portion of the spool body and a second sealing interface associated with the second end portion of the spool body and axially spaced from the first sealing interface when the spool body is in the shutoff position, and
a plunger coupled to the spool body for movement therewith; and

an actuator device that cooperates with the plunger to move the spool body between the metering and shutoff positions.

14. The metering valve according to claim 13 , wherein the actuator device comprises a solenoid and the engine comprises a gas turbine engine.

15. The metering valve according to claim 13 , wherein the spool body includes a second reduced diameter portion between the first end portion and the central portion that is defined by a diameter that is less than the outermost diameter at the central portion, and wherein the compliant seal assembly surrounds the second reduced diameter portion.

16. The metering valve according to claim 13 , wherein the bore has at least a first portion defined by a first diameter and a second portion that is defined by a second diameter that is greater than the first diameter, and wherein the first portion is in direct sliding engagement with the central portion of the spool body and the second portion provides an enlarged area that at least partially ov

Assignees

• Hamilton Sundstrand Corp

Inventors

• Marocchini Francis P
• Rickis Aaron F

Classifications

• F16K1/443

  the seats being in series · CPC title

• F16K31/0655

  Lift valves · CPC title

• F16K31/0693

  Pressure equilibration of the armature · CPC title

• F16K3/267

  Combination of a sliding valve and a lift valve (F16K3/262, F16K3/265 take precedence) · CPC title

• F02C9/263 Primary

  by means of fuel metering valves · CPC title