Modulating balance ported three way valve

Patent metadata

Field	Value
Publication number	US-9371920-B2
Application number	US-201314766282-A
Country	US
Kind code	B2
Filing date	Dec 13, 2013
Priority date	Feb 14, 2013
Publication date	Jun 21, 2016
Grant date	Jun 21, 2016

Abstract

Provided is a three-way valve having and actuator ( 66 ) and first ( 100 ) and second ( 102 ) piston assemblies movable by the actuator ( 66 ) and arranged in tandem, wherein each piston assembly ( 100,102 ) has a backside ( 104,106 ) in fluid communication with a common pressure source for pressure balancing the piston assemblies ( 100,102 ). By having the backsides ( 104,106 ) in fluid communication with a common pressure source and by isolating the piston assemblies ( 100,102 ) from a main chamber, an axial load on the actuator ( 66 ) is minimized, thereby allowing for more compact valve designs.

First claim

What is claimed is:

1. A modulating balance ported three-way valve including:
a valve body having an inlet port, a chamber, and first and second outlet ports in fluidic communication with the inlet port via the chamber;
an actuator having an output shaft;
a connection rod disposed in the valve body and coupled to the actuator such that the actuator effects longitudinal movement of the connection rod, the connection rod including a passage; and
first and second piston assemblies coupled to the connection rod, each piston assembly having a backside in fluid communication with the other backside via the passage in the connection rod for pressure balancing the piston assemblies.

2. The modulating balance ported three-way valve according to claim 1 , wherein the first and second piston assemblies are movable between a first position allowing fluid entering the inlet port to flow through the first outlet and preventing fluid flow through the second outlet, a second position preventing fluid flow through the first outlet and allowing the fluid to flow through the second outlet, and a plurality of third positions allowing a varying amount of the fluid to flow through the first and second outlets.

3. The modulating balance ported three-way valve according to claim 1 , wherein each backside is in fluid communication with a common pressure source and the common pressure source is the fluid entering the inlet port.

4. The modulating balance ported three-way valve according to claim 3 , wherein the connection rod includes at least one port through which the fluid in the chamber enters the passage.

5. The modulating balance ported three-way valve according to claim 2 , wherein the connection rod includes a port near each end of the connection rod in communication with a respective passage in the piston assemblies for venting fluid.

6. The modulating balance ported three-way valve according to claim 2 , wherein each piston assembly includes a seal near the backside of the respective piston assembly for retaining the pressure from the common pressure source.

7. The modulating balance ported three-way valve according to claim 6 , wherein each piston assembly includes a piston body through which an end of the connection rod extends and the seal near the backside of the respective piston assembly.

8. The modulating balance ported three-way valve according to claim 7 , wherein each piston assembly further includes a seal retainer coupled to a backside of the respective piston to secure the seal.

9. The modulating balance ported three-way valve according to claim 7 , wherein each piston assembly further includes a nose piece coupled to the respective piston, each nose piece having a passage in communication with the passage in the connection rod for venting fluid.

10. The modulating balance ported three-way valve according to claim 7 , wherein the second piston assembly further includes a retainer coupled to the respective end of the connection rod to couple the second piston assembly to the connection rod.

11. The modulating balance ported three-way valve according to claim 1 , wherein the actuator is an electric motor.

12. The modulating balance ported three-way valve according to claim 10 , wherein the electric motor is a stepper motor.

13. The modulating balance ported three-way valve according to claim 11 , wherein the motor has an output shaft and the connection rod is coupled to the output shaft of the motor such that rotation of the output shaft effects longitudinal movement of the connection rod.

14. The modulating balance ported three-way valve according to claim 13 , further including a drive screw rotatably coupled to the output shaft via a reduction gear assembly, and a plunger supported in the valve body for longitudinal movement along the drive screw, wherein a head of the plunger is coupled to an end of the connection rod.

15. The modulating balance ported three-way valve according to claim 1 , further including a plug for closing one end of the valve body and an adapter secured to a motor housing for closing another end of the valve body.

16. The modulating balance ported three-way valve according to claim 15 , wherein a chamber is formed between the adapter and the backside of the first piston assembly for receiving fluid from the common pressure source and a chamber is formed between the plug and the backside of the second piston assembly for receiving fluid from the common pressure source.

17. The modulating balance ported three-way valve according to claim 1 , wherein when the first and second piston assemblies are in the first position, the second piston assembly is seated against a second valve seat in the valve body, and when the first and second piston assemblies are in the second position, the first piston assembly is seated against a first valve seat in the valve body.

18. A method of modulating a three-way valve having a valve body, an actuator, a connection rod disposed in the valve body and first and second piston assemblies arranged in tandem and coupled to the connection rod, the method including:
controlling the tandem piston assemblies such that while the first piston assembly is seated against a first seat in the valve body to prevent fluid flow through a first outlet the second piston assembly is unseated from a second seat in the valve body to allow fluid flow through a second outlet, while the second piston assembly is seated against the second seat to prevent fluid flow through the second outlet the first piston assembly is unseated from the first seat to allow fluid flow through the first outlet, and while the first and second piston assemblies are unseated from the first and second seats respectively fluid flows through both the first and second outlets; and
pressure balancing the piston assemblies by using a passage in the connection rod that effects fluid communication between the backsides of the piston assemblies.

19. The method according to claim 18 , wherein while the first and second piston assemblies are unseated from the first and second seats respectively, the method further includes controlling the tandem piston assembly to vary the percentage of flow between the outlets.

20. A modulating balance ported three way valve comprising two balance ported piston assemblies, a connecting rod coupled to the ported piston assemblies having a passageway that is in fluid communication with a main chamber of the valve and respective sides of the piston assemblies opposite the main chamber of the valve to communicate pressure from the main chamber to the respective opposite sides of the pistons, and a motor actuator for controlling the position of the piston assemblies.

Assignees

• Parker Hannifin Corp

Inventors

• Coates Iii Gordon Richard
• Kuhl Scott L

Classifications

• F16K11/048 Primary

  with valve seats positioned between movable valve members · CPC title

• F16K31/04

  using a motor · CPC title