WO2015003117A1

WO2015003117A1 - Full pressure limiting valve

Info

Publication number: WO2015003117A1
Application number: PCT/US2014/045369
Authority: WO
Inventors: Anh Hung VU; James William REINHOLDT
Original assignee: Eaton Corporation
Priority date: 2013-07-03
Filing date: 2014-07-03
Publication date: 2015-01-08

Abstract

A pressure limiting valve (10) includes a housing (12) having a primary fluid passageway that includes a primary inlet port (14) and a primary outlet port (16). The housing may include a piston chamber (62) having a secondary inlet port (22). In embodiments, a valve spool (40) is supported for axial movement within the primary fluid passageway of the housing, the valve spool being movable between an opened position to allow fluid to flow through the primary fluid passageway and a closed position to restrict or prohibit the flow of fluid through the primary fluid passageway. A piston (60) may be supported within the piston chamber of the housing, and may be movable from a first position to a second position in response to increased fluid pressure within the piston chamber. Movement of the piston from the first position to the second position can move the valve spool from the opened position to the closed position.

Description

FULL PRESSURE LIMITING VALVE

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of United States Provisional Application Serial No. 61/842,672, filed July 3, 2013, the disclosure of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

[0002] The present disclosure relates to pressure limiting valves, including a fuel pressure limiting valve that can regulate a supply of hydraulic fluid delivered to a hydraulic motor of a fuel pump in response to an outlet pressure of the fuel pump.

BACKGROUND

[0003] Aerial refueling systems can be used to transfer fuel from a tanker aircraft to a receiver aircraft during flight. In a typical aerial refueling system, a flexible hose or boom generally may extend from the tanker aircraft and can include a coupling that connects to a probe on the receiver aircraft. Once a connection is made between the tanker aircraft and the receiver aircraft, a fuel pump provided on the tanker aircraft can pump a supply of fuel through the hose or boom to the receiver aircraft.

[0004] Aerial refueling systems typically include fuel pressure regulating devices that can regulate the outlet pressure from the tanker aircraft and reduce downstream pressure surges, which might otherwise damage fuel system components on the receiver aircraft. One example of a pressure regulating device is a pressure relief valve, which can be located downstream of the fuel pump. Pressure relief valves operate effectively to limit the downstream pressure in the refueling system, however these valves can be relatively large in size and heavy in weight.

Another example of a pressure regulating device is a pressure regulator, which can also be located downstream of the fuel pump. Pressure regulators operate effectively to regulate downstream pressure in the refueling system, however they can increase pressure drops and reduce the flow rate in the refueling system, which can result in the need for a more powerful and heavier fuel pump. In addition, the pressure regulators themselves can be relatively large in size and heavy in weight.

[0005] Thus, it would be desirable to provide a fuel pressure limiting valve located upstream of the fuel pump that can regulate the outlet pressure of the fuel pump.

SUMMARY

[0006] A pressure limiting valve according to an embodiment of the present disclosure may include a housing having a primary fluid passageway that includes a primary inlet port and a primary outlet port. The housing may also include a piston chamber having a secondary inlet port. A valve spool may be supported for axial movement within the primary fluid passageway of the housing. The valve spool may be movable between an opened position to allow fluid to flow through the primary fluid passageway and a closed position to restrict or prohibit the flow of fluid through the primary fluid passageway. A piston may be supported within the piston chamber of the housing. The piston may be movable from a first position to a second position in response to increased fluid pressure within the piston chamber. Movement of the piston from the first position to the second position can move the valve spool from the opened position to the closed position.

[0007] Various aspects of the present disclosure will become apparent to those skilled in the art from the following detailed description of the various embodiments, when read in light of the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Embodiments of the present disclosure will now be described, by way of example, with reference to the accompanying drawings.

[0009] FIG. 1 is a perspective view of a fuel pressure limiting valve for a hydraulic motor driven fuel pump according to an embodiment of the present disclosure.

[0010] FIG. 2 is a cross-sectional side view of the fuel pressure limiting valve in FIG. 1 shown in an opened position.

[0011] FIG. 3 is a cross-sectional side view of the fuel pressure limiting valve in FIG. 1 shown in an intermediate position. [0012] FIG. 4 is a cross-sectional side view of the fuel pressure limiting valve in FIG. 1 shown in a closed position.

DETAILED DESCRIPTION

[0013] Reference will now be made in detail to embodiments of the present disclosure, examples of which are described herein and illustrated in the accompanying drawings. While the invention will be described in conjunction with embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims.

[0014] Referring now to FIG. 1, a fuel pressure limiting valve according to an embodiment of the present disclosure is shown generally at 10. In a non-limiting example, the fuel pressure limiting valve 10 can be used to regulate the flow of hydraulic fluid to a hydraulic motor that, in turn, powers a fuel pump in an aerial refueling system. By regulating the flow of hydraulic fluid to the motor, the fuel pressure limiting valve 10 can regulate the outlet pressure of the fuel pump. As generally disclosed below, the fuel pressure limiting valve 10 may use the outlet pressure of the fuel pump to regulate the flow of hydraulic fluid to the motor. It should be fully appreciated, however, that the fuel pressure limiting valve 10 can be used in any suitable environment and for any suitable purpose.

[0015] As generally shown, the fuel pressure limiting valve 10 may include a housing 12 that can define a generally cylindrical internal chamber having a closed end and an open end. The housing 12 may also define a primary fluid passageway having a primary inlet port 14 and a primary outlet port 16, which can extend through a side wall of the housing 12. The primary inlet port 14 and the primary outlet port 16 can be axially spaced apart from one another along a longitudinal axis of the housing 12, although such is not required. The housing 12 may also include a return port 18 that can be in fluid communication with the internal chamber, at least one purpose of which will be generally disclosed below. In other embodiments, the housing 12 can have any suitable shape and may include other numbers or configurations of fluid ports as desired. [0016] The fuel pressure limiting valve 10 may also include a valve cover 20 that can be secured to the open end of the housing 12. The valve cover 20 can be secured to the housing 12 using a plurality of fasteners or other suitable connection such as, for example, a clamped connection. The illustrated valve cover 20 may define a generally cylindrical internal chamber having a secondary inlet port 22 and a drain port 24 in fluid communication therewith, at least some purposes of which will be generally disclosed below. In other embodiments, the valve cover 20 can have any suitable shape and may include other numbers or configurations of fluid ports as desired.

[0017] With reference to FIGS. 2 through 4, internal components of the fuel pressure limiting valve 10 will be generally described. As generally shown, the fuel pressure limiting valve 10 may include an internal sleeve 30 that is disposed within the internal chamber of the housing 12. The internal sleeve 30 can be a generally cylindrical member and may define a plurality of apertures 32 that extend through a side wall thereof. In one embodiment, for example, a first set of the apertures 32A may generally correspond for fluid communication with the primary inlet port 14, and a second set of the apertures 32B may generally correspond for fluid communication with the primary outlet port 16. As such, a primary fluid passageway of the fuel pressure limiting valve 10 may enter the housing 12 through the primary inlet port 14, enter the internal sleeve 30 through the first set of apertures 32A, travel in an axial direction within the internal sleeve 30, exit the internal sleeve 30 through the second set of apertures 32B, and exit the housing 12 through the primary outlet port 16. Some purposes of the primary fluid passageway will be generally disclosed below.

[0018] The internal sleeve 30 may also include a plurality of seals that can circumferentially extend around an outer surface of the internal sleeve 30 for engagement with an inner surface of the housing 12, although such may not be required. The seals can be located on any portion of the internal sleeve 30 such as, for example, adjacent to and between the primary inlet port 14 and the primary outlet port 16. In other embodiments, the internal sleeve 30 may include any suitable number, configuration, or type of seals as desired.

[0019] A valve spool 40 may be supported for axial movement within the internal sleeve 30. As generally disclosed below, the valve spool 40 may be configured to move between an opened position in which hydraulic fluid is permitted to flow through the primary fluid passageway of the housing 12 (e.g., as generally shown in FIG. 2), a closed position in which hydraulic fluid is prevented or otherwise restricted from flowing through the primary fluid passageway of the housing 12 (e.g., as generally shown in FIG. 4), or any position in between to adjust the rate of fluid flow through the housing 12 (e.g., as generally shown in FIG. 3).

[0020] In an embodiment, portions of the valve spool 40 may have an outer diameter that is generally the same or slightly smaller than an inner diameter of the internal sleeve 30. Thus, these portions of the valve spool 40 can create or provide an interference fit with the internal sleeve 30 and may act as sealing surfaces as the valve spool 40 moves along an inner surface of the internal sleeve 30. The valve spool 40 may include any type of sealing features or sealing components to facilitate a sealing connection with the internal sleeve 30, although such is not required.

[0021] The valve spool 40 may also include a recessed portion that is located or otherwise provided between the sealing portions of the valve spool 40 described above. The recessed portion may have an outer diameter that is smaller than the outer diameters of the sealing portions, thereby forming a chamber between an outer surface of the valve spool 40 and an inner surface of the internal sleeve 30. As generally shown in FIG. 2, the first and second set of apertures 32 of the internal sleeve 30 may be in fluid communication with the recessed portion of the valve spool 40 when the fuel pressure limiting valve 10 is in the opened position. This arrangement can create a fluid passageway between the first and second sets of apertures 32. It should be appreciated, however, that the valve spool 40 can have any other suitable shape or configuration to accomplish the purposes described in the present disclosure.

[0022] The fuel pressure limiting valve 10 may also include a spring member configured to bias the valve spool 40 in the opened position. As generally shown, a spring member 42 may be disposed between an end flange of the valve spool 40 and a radially extending shoulder provided on the internal sleeve 30. It should become apparent that the spring member 42 can be selected to provide a desired spring load and spring rate to automatically control operation of the fuel pressure limiting valve 10, which in turn can regulate the outlet pressure of the fuel pump within a desired pressure range. In a non-limiting example, the fuel pressure limiting valve 10 can be configured to regulate the outlet pressure of the fuel pump between 100 psig and 120 psig. It should be appreciated, however, that the fuel pressure limiting valve 10 can be used to regulate the outlet pressure of the fuel pump within any suitable pressure range.

[0023] The valve spool 40 may also define a pressure relief conduit 44 that can extend along an axis of the valve spool 40, although such is not required. The pressure relief conduit 44 may extend from an open end of the valve spool nearest the closed end of the housing 12 and exit into a chamber that houses the spring member 42. Thus, the pressure relief conduit 44 may be configured to relieve pressure that might otherwise accumulate between the end of the valve spool 40 and the closed end of the housing 12. In turn, the return port 18 of the housing 12 can communicate with the chamber that houses the spring member 42 to relieve pressure in that chamber.

[0024] The fuel pressure limiting valve 10 may also include an adjuster 50 that is supported on an end of the internal sleeve 30. In an embodiment, the adjuster 50 can be a internally threaded member that may be supported for axial movement on the internal sleeve 30. The adjuster 50 can be configured to selectively increase or decrease an operating length of the spring member 42. As such, the fuel pressure limiting valve 10 can be adjusted to control the operating range of the fuel pressure limiting valve 10, which in turn can regulate the outlet pressure of the fuel pump within a desired pressure range. In other embodiments, the adjuster 50 can be any suitable mechanism that is configured to selectively adjust the operating range of the fuel pressure limiting valve 10.

[0025] The fuel pressure limiting valve 10 may also include a piston 60 that can be supported for axial movement within a chamber of the valve cover 20 of the housing 12. As generally shown, the piston 60 may include a head portion that can be supported by the valve cover 20 and a stem that can extend from the head portion for engagement with an end of the valve spool 40. The piston 60 can be configured to move the valve spool 40 between the opened and closed positions. To accomplish this, for example, a piston chamber 62 may be formed between the head portion of the piston 60 and an end surface of the valve cover 20. The secondary inlet port 22 of the valve cover 20 may be in fluid communication with the piston chamber 62. The drain port 24 of the valve cover 20 can be located on the backside of the piston 60 nearest the stem to vent pressure and/or drain fluid that may otherwise accumulate between the piston 60 and the adjuster 50. [0026] An operation of the fuel pressure limiting valve 10 will now be described with reference to FIGS. 2 through 4. As briefly described above, the fuel pressure limiting valve 10 may be initially biased in the opened position, for example, as generally shown in FIG. 2. In the opened position, hydraulic fluid can generally flow in unrestricted manner through the primary fluid passageway (i.e., into the primary inlet port 14, through the internal sleeve 30, and out of the housing 12 through the primary outlet port 16) to power the hydraulic motor of the fuel pump.

[0027] A supply of pressurized fuel from the outlet of the fuel pump may be routed to the secondary inlet port 22 in the valve cover 20. If the outlet pressure from the fuel pump exceeds an upper limit, then the fluid pressure in the piston chamber 62 may generate a force on the piston 60 that can overcome an opposing force exerted on the valve spool 40 by the spring member 42. As a result, the piston 60 can begin to move the valve spool 40 from the opened position to an intermediate position, for example, as generally shown in FIG. 3. In the intermediate position, a portion of the valve spool 40 can partially block the second set of apertures 32B in the internal sleeve 30 that correspond with the primary outlet port 16. In doing so, the flow rate and fluid pressure of hydraulic fluid passing through the primary fluid passageway of the fuel pressure limiting valve 10 can be restricted, which in turn restricts the amount of hydraulic fluid being delivered to the hydraulic motor of the fuel pump.

[0028] If the outlet pressure from the fuel pump continues to increase, then the piston 60 can continue to move the valve spool 40 from the intermediate position toward a closed position, for example, as generally shown in FIG. 4. In the closed position, a portion of the valve spool 40 can completely or substantially close and seal the second set of apertures 32B in the internal sleeve 30 that correspond with the primary outlet port 16. As a result, the fuel pressure limiting valve 10 may be configured to prohibit or substantially restrict the flow of hydraulic fluid to the hydraulic motor of the fuel pump.

[0029] The outlet pressure of the fuel pump may be directly proportional to the amount of hydraulic fluid that is delivered to the hydraulic motor, and vice versa. As such, the fuel pressure limiting valve 10 can be configured to automatically regulate the amount of hydraulic fluid that is delivered to the hydraulic pump in response to the outlet pressure of the fuel pump. Thus, it should be appreciated that the fuel pressure limiting valve 10 of the present disclosure may be configured to automatically regulate the outlet pressure of the fuel pump within a desired pressure range.

[0030] The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and various modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to explain the principles of the invention and its practical application, to thereby enable others skilled in the art to utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims and their equivalents.

Claims

CLAIMS What is claimed is:

1. A pressure limiting valve for regulating a supply of pressurized fluid delivered to a hydraulic motor of a fluid pump, the pressure limiting valve comprising:

a housing having a primary fluid passageway that includes a primary inlet port and a primary outlet port, and a piston chamber having a secondary inlet port;

a valve spool supported for axial movement within the primary fluid passageway of the housing, wherein the valve spool is movable between an opened position to allow fluid to flow through the primary fluid passageway and a closed position to restrict or prohibit the flow of fluid through the primary fluid passageway; and

a piston supported within the piston chamber of the housing, wherein the piston is movable from a first position to a second position in response to increased fluid pressure within the piston chamber, and movement of the piston from the first position to the second position moves the valve spool from the opened position to the closed position.

2. The pressure limiting valve of claim 1, including an internal sleeve supported within the primary fluid passageway of the housing, wherein the internal sleeve includes a first set of apertures in fluid communication with the primary inlet port and a second set of apertures in fluid communication with primary outlet port.

3. The pressure limiting valve of claim 2, wherein the first set of apertures are in fluid communication with the second set of apertures when the valve spool is in the opened position.

4. The pressure limiting valve of claim 2, wherein the valve spool blocks at least one of the first set of apertures and the second set of apertures in the internal sleeve when the valve spool is in the closed position.

5. The pressure limiting valve of claim 1, including a biasing member disposed between a portion of the housing and the valve spool to bias the valve spool in the opened position.

6. The pressure limiting valve of claim 5, wherein the biasing member is supported within an internal chamber of the housing, and the housing includes a return port in fluid communication with the internal chamber.

7. The pressure limiting valve of claim 2, including a threaded adjuster supported on the internal sleeve, wherein the threaded adjuster is configured to axially adjust the internal sleeve within the primary fluid passageway.

8. The pressure limiting valve of claim 1, wherein a pressure relief conduit extends through the valve spool to relieve pressure in a chamber formed between an end of the valve spool and a closed end of the housing.

9. The pressure limiting valve of claim 1, including a valve cover attached to the housing, and the secondary inlet port is provided in the valve cover.

10. The pressure limiting valve of claim 9, wherein the piston chamber is defined by the valve cover.

11. The pressure limiting valve of claim 9, wherein the valve cover includes a drain port that is in fluid communication with a portion of the piston chamber.

12. The pressure limiting valve of claim 1, wherein the piston includes a stem that is engaged with the valve spool so that movement of the piston moves the valve spool.

13. A fuel pressure limiting valve for use in an aerial refueling system to regulate a supply of hydraulic fluid delivered to a hydraulic motor of a fuel pump in response to outlet pressure of said fuel pump, the fuel pressure limiting valve comprising:

a housing having a primary fluid passageway that includes a primary inlet port and a primary outlet port configured to supply hydraulic fluid to said hydraulic motor, and a piston chamber having a secondary inlet port configured to receive a supply of pressurized fuel from an outlet of said fuel pump;

a piston supported within the piston chamber of the housing, wherein the piston is movable from a first position to a second position in response to increased outlet pressure of said fluid pump, and movement of the piston from the first position to the second position moves the valve spool from the opened position to the closed position.

14. The fuel pressure limiting valve of claim 13, including an internal sleeve supported within the primary fluid passageway of the housing, wherein the internal sleeve includes a first set of apertures in fluid communication with the primary inlet port and a second set of apertures in fluid communication with primary outlet port.

15. The fuel pressure limiting valve of claim 14, wherein the first set of apertures are in fluid communication with the second set of apertures when the valve spool is in the opened position.

16. The fuel pressure limiting valve of claim 14, wherein the valve spool impedes or blocks at least one of the first set of apertures and the second set of apertures in the internal sleeve when the valve spool is in the closed position.

17. The fuel pressure limiting valve of claim 14, including a threaded adjuster supported on the internal sleeve, and the threaded adjuster is configured to axially adjust the internal sleeve within the primary fluid passageway.

18. The fuel pressure limiting valve of claim 13, including a valve cover attached to the housing, and the secondary inlet port is provided in the valve cover.

19. The fuel pressure limiting valve of claim 18, wherein the valve cover includes a drain port that is in fluid communication with a portion of the piston chamber.

20. The fuel pressure limiting valve of claim 13, wherein the piston includes a stem that is engaged with the valve spool so that movement of the piston moves the valve spool.