Pressure feedback shuttle valve
View Patent ↗A shuttle valve 10 includes a valve body 11 , a first inlet port 12 , a second inlet port 13 , an outlet port 14 , and a shuttle poppet 15 . The inlet ports 12 and 13 may be connected to different sources of fluid pressure, and the shuttle valve 10 connects the higher pressure one of the inlet ports 12, 13 to the outlet port 14 and isolates the lower pressure one of the inlet ports 12, 13 from the outlet port 14 . First valve members 26, 46 selectively open and close fluid communication between the first inlet port 12 and the outlet port 14 . Second valve members 27, 47 selectively open and close fluid communication between the second inlet port 13 and the outlet port 14 . The shuttle valve 10 includes cushioning cavities 50 and 51 and feedback passages 56, 59 and 60 to reduce shock or water hammer in the system.
1. A shuttle valve comprising:
a valve body having first and second inlets and an outlet and a central cavity located between said first and second inlets;
a shuttle poppet located in said cavity and movable between a first position and a second position and intermediate positions between said first and second positions,
said shuttle poppet including a first valve surface between said first inlet and said outlet, said first valve surface in said first position contacting a surface of said valve body to close fluid pressure communication between said first inlet and said outlet,
said shuttle poppet including a second valve surface between said second inlet and said outlet, said second valve surface in said second position contacting another surface of said valve body to close fluid pressure communication between said second inlet and said outlet,
a variable volume cushioning cavity, said cushioning cavity being defined by surfaces of said shuttle poppet and surfaces of said valve body as said shuttle poppet moves from said first position to said intermediate positions to said second position,
said shuttle poppet including a first net lateral cross sectional area exposed to fluid pressure in said first inlet port and a second net lateral cross sectional area exposed to fluid pressure in said second inlet port and a third net lateral cross sectional area exposed to fluid pressure in said cushioning cavity when said shuttle poppet is in at least one of said intermediate positions, fluid pressure in said cushioning cavity acting against said third net cross sectional area in a direction to cushion movement of said shuttle poppet from said intermediate positions toward said second position, and
at least one feedback passage establishing fluid pressure communication between said first inlet and said cushioning cavity during at least a portion of said movement of said shuttle poppet from said intermediate positions to said second position.
2. A shuttle valve as set forth in claim 1 , wherein said outlet is disposed between said first inlet and said second inlet, and said cushioning cavity is disposed between said second inlet and said outlet.
3. A shuttle valve as set forth in claim 2 , wherein said cushioning cavity is disposed between said second valve surface and said outlet.
4. A shuttle valve as set forth in claim 3 , wherein said cushioning cavity is defined by a radially inwardly facing surface of said central cavity and by a radially outwardly facing surface of said shuttle poppet and by said third net lateral cross sectional area.
5. A shuttle valve as set forth in claim 4 , wherein at least a portion of said feedback passage is disposed within said shuttle poppet, and said radially inwardly facing surface and said radially outwardly facing surface define an annular leakage flow path extending from said cushioning chamber.
6. A shuttle valve as set forth in claim 5 , wherein the entirety of said feedback passage is disposed within said shuttle poppet, said feedback passage includes an axially extending passage portion and a radially extending passage portion, and said radially extending passage portion extends between said axially extending portion and said cushioning cavity.
7. A shuttle valve as set forth in claim 2 , wherein said cushioning cavity is defined between radially opposite surfaces of said central cavity and said shuttle poppet and by said third net lateral cross sectional area, said cushioning cavity being in fluid communication with said second inlet when said shuttle poppet is in said intermediate position, and radially opposing surfaces of said cushioning cavity being spaced apart to allow variations of the volume of said cushioning cavity and to allow only restricted fluid leakage communication between said cushioning cavity and at least one of said second inlet and said outlet when said shuttle poppet is in said intermediate position.
8. A shuttle valve as set forth in claim 7 , wherein said volume is at a minimum volume when said shuttle poppet is in said second at rest position.
9. A shuttle valve as set forth in claim 1 , including a fluid flow orifice in said feedback passage restricting flow through said passage.
10. A shuttle valve comprising:
a valve body having first and second inlets and an outlet;
a shuttle poppet movable between a first at rest position and a second at rest position and intermediate positions between said first and second at rest positions,
said shuttle poppet including a first valve surface between said first inlet and said outlet, said first valve surface in said first at rest position contacting a surface of said valve body to close fluid pressure communication between said first inlet and said outlet, said first valve surface in some of said intermediate positions and in said second at rest position being spaced from said contacted surface of said valve body to open fluid pressure communication between said first inlet and said outlet,
said shuttle poppet including a second valve surface between said second inlet and said outlet, said second valve surface in said second at rest position contacting another surface of said valve body to close fluid pressure communication between said second inlet and said outlet, said second valve surface in at least some of said intermediate positions and in said first at rest positions being spaced from said second mentioned contacted surface of said valve body to open fluid pressure communication between said second inlet and said outlet,
a variable volume cushioning cavity, said variable volume cushioning cavity being defined by moving surfaces of said shuttle poppet and stationary surfaces of said valve body as said shuttle poppet moves from some of said intermediate positions to said second position,
said shuttle poppet including a net lateral cross sectional area exposed to fluid pressure in said cushioning cavity when said shuttle poppet is in some of said intermediate positions and facing in a direction so that fluid pressure in said cushioning cavity acting against said net cross sectional area imposes a force on said shuttle poppet in a direction to cushion movement of said shuttle poppet from some of said intermediate positions toward said second position, and
a passage establishing fluid pressure communication between said first inlet and said cushioning cavity during at said movement of said shuttle poppet from some of said intermediate positions to said second position.
11. A shuttle valve as set forth in claim 10 , wherein at least a portion of said feedback passage is disposed within said shuttle poppet.
12. A shuttle valve as set forth in claim 10 , wherein the entirety of said feedback passage is disposed within said shuttle poppet, said feedback passage includes an opening on the outer surface of said shuttle poppet, said valve body includes a closing surface, said opening is axially spaced from said closing surface of said valve body and is in fluid pressure communication with said cushioning cavity when said shuttle poppet is in at least some of said intermediate positions, and said opening is in radial alignment with said closing surface of said valve body and is in fluid leakage communication with said cushioning cavity and with said outlet when said poppet is in said second at rest position.
13. A shuttle valve as set forth in claim 12 , wherein the entirety of said feedback passage is disposed within said shuttle poppet, and said feedback passage includes a fluid flow orifice restricting flow through said passage.
14. A shuttle valve as set forth in claim 13 , wherein said cushioning cavity is a variable volume cavity, and said volume is at a minimum volume when said shuttle poppet is in said second at rest position.
15. A shuttle valve as set forth in claim 14 , wherein said outlet is disposed between said first inlet and said second inlet, and said cushioning cavity is disposed between said second valve surface and said outlet.
16. A shuttle valve as set forth in claim 15 , wherein said cushioning cavity is defined between radially opposite cylindrical surfaces of said valve body and said shuttle poppet and by said net lateral cross sectional area, said cushioning cavity being in fluid communication with second inlet when said shuttle poppet is in some of said first intermediate positions, and radially opposing surfaces of said cushioning cavity defining an annular controlled leakage path to allow variations of the volume of said cushioning cavity and to allow only restricted fluid leakage between said cushioning cavity and at least one of said second inlet and said outlet when said shuttle poppet is in some of said intermediate positions.
17. A shuttle valve comprising:
a valve body having first and second inlets and an outlet,
a shuttle poppet movable between a first at rest position and a second at rest position and intermediate positions between said first and second at rest positions,
said shuttle poppet including a first valve surface between said first inlet and said outlet, said first valve surface in said first at rest position contacting a surface of said valve body to close fluid pressure communication between said first inlet and said outlet, said first valve surface in said intermediate positions and in said second at rest position being spaced from said contacted surface of said valve body to open fluid pressure communication between said first inlet and said outlet,
said shuttle poppet including a second valve surface between said second inlet and said outlet, said second valve surface in said second at rest position contacting another surface of said valve body to close fluid pressure communication between said second inlet and said outlet, said second valve surface in said intermediate positions and in said first position being spaced from said second mentioned contacted surface of said valve body to open fluid pressure communication between said first inlet and said outlet,
a first variable volume cushioning cavity, said first variable volume cushioning cavity being defined by moving surfaces of said shuttle poppet and stationary surfaces of said valve body as said shuttle poppet moves between said intermediate positions and said first at rest position, said first variable volume cushioning cavity being disposed between said first valve surface and said outlet,
said shuttle poppet including a net lateral cross sectional area exposed to fluid pressure in said first cushioning cavity when said shuttle poppet is in at least one of said intermediate positions and facing in a direction so that fluid pressure in said first cushioning cavity acting against said net cross sectional area imposes a force on said shuttle poppet in a direction to cushion movement of said shuttle poppet from said intermediate positions toward said first position,
a passage establishing fluid pressure communication between said second inlet and said first cushioning cavity during at least a portion of said movement of said shuttle poppet from said intermediate positions to said first position,
a second variable volume cushioning cavity, said second variable volume cushioning cavity being defined by other moving surfaces of said shuttle poppet and other stationary surfaces of said valve body as said shuttle poppet moves between said intermediate positions and said second at rest position, said second variable volume cushioning cavity being disposed between said second valve surface and said outlet,
said shuttle poppet including another net lateral cross sectional area exposed to fluid pressure in said second cushioning cavity when said shuttle poppet is in at least one of said intermediate positions and facing in a direction so that fluid pressure in said second cushioning cavity acting against said other net cross sectional area imposes a force on said shuttle poppet in a direction to dampen movement of said shuttle poppet from said intermediate positions toward said second at rest position,
said passage also establishing fluid pressure communication between said first inlet and said second cushioning cavity during at least a portion of said movement of said shuttle poppet from said intermediate positions to said second position, and
at least a portion of said feedback passage being disposed within said shuttle poppet.
18. A shuttle valve as set forth in claim 17 , wherein the entirety of said feedback passage is within said shuttle poppet.
19. A shuttle valve as set forth in claim 18 , including a fluid flow orifice in said feedback passage restricting flow through said passage.
20. A shuttle valve as set forth in claim 19 , wherein said first and second cushioning cavities are defined between radially opposite cylindrical surfaces of said valve body and said shuttle poppet and by said respective first and second net lateral cross sectional areas, radially opposing surfaces of said first cushioning cavity being axially slidable relative to one another and defining an annular controlled leakage path to allow variations of the volume of said first cushioning cavity and to provide restricted fluid leakage communication between said first cushioning cavity and at least one of said first inlet and said outlet when said shuttle poppet is in at least one of said intermediate positions, radially opposing surfaces of said second cushioning cavity being axially slidable relative to one another and defining an annular controlled leakage path to allow variations of the volume of said second cushioning cavity and to provide restricted fluid leakage between said second cushioning cavity and at least one of said second inlet and said outlet when said shuttle poppet is in at least one of said second intermediate positions.