Microvalve device suitable for controlling a variable displacement compressor

• US 20070172362A1
• Filed: 03/13/2007
• Published: 07/26/2007
• Est. Priority Date: 11/24/2003
• Status: Abandoned Application

• Current Assignee: Dunan Microstaq, Inc. (Zhejiang Dun'an Artificial Environment Co., Ltd.)
• Original Assignee: Dunan Microstaq, Inc. (Zhejiang Dun'an Artificial Environment Co., Ltd.)
• Inventors: Fuller, Edward, Chance, Jeffrey, Uibel, Jeffrey, Booth, Steven, Davies, Brady
• Application Number:
  US11/717,310
• Publication Number:
  US 20070172362A1
• Time in Patent Office: Days
• US Class Current: 417/222.200
• CPC Class Codes: F04B 2027/1827 between crankcase and discharge chamber
• CPC Class Codes: F04B 2027/1831 between crankcase and suction chamber
• CPC Class Codes: F04B 2027/1854 External parameters
• CPC Class Codes: F04B 27/1804 Controlled by crankcase pressure
• CPC Class Codes: F15C 5/00 Manufacture of fluid circuit elements; Manufacture of assemblages of such elements integrated circuits
• CPC Class Codes: F16K 11/056 with ball-shaped valve members
• CPC Class Codes: F16K 2099/0076 using electrical discharge machining [EDM], milling or drilling
• CPC Class Codes: F16K 2099/008 Multi-layer fabrications
• CPC Class Codes: F16K 2099/009 Fluid power devices
• CPC Class Codes: F16K 99/0001 Microvalves microdevices B81B1/00; manufacture or treatment of devices or systems in or on a substrate B81C1/00; microfluidic structures B01L3/5027; micropumps F04B19/006
• CPC Class Codes: F16K 99/0011 Gate valves or sliding valves
• CPC Class Codes: F16K 99/0034 Operating means specially adapted for microvalves
• CPC Class Codes: F16K 99/0044 using thermo-electric means
• CPC Class Codes: F16K 99/0059 actuated by a pilot fluid
• CPC Class Codes: Y10T 137/86614 Electric
• CPC Class Codes: Y10T 137/86622 Motor-operated
• CPC Class Codes: Y10T 137/8663 Fluid motor
• CPC Class Codes: Y10T 137/87209 Electric

Abstract

A device is disclosed for controlling a variable displacement compressor. The device comprises a microvalve operated control valve. A microvalve device for controlling fluid flow and a micro spool valve for use as a microvalve are also disclosed.

Claims

1. A control valve for a variable displacement compressor having a piston having a displacement within a compression chamber, the compression chamber admitting a gas from a suction area at a suction pressure and discharging the gas to a discharge area at a discharge pressure, a gas-filled crankcase chamber having a crankcase pressure, the displacement of the piston varying according to the crankcase pressure, the control valve controlling the crankcase pressure, the control valve comprising:

a discharge pressure valve portion for controlling gas communication between the discharge area and the crankcase chamber;

a reference chamber isolated from the crankcase chamber having a reference pressure, the reference pressure established by a flow of the gas from the discharge area to the reference chamber or by a flow of the gas from the reference chamber to the suction area;

a pressure sensitive member having a suction pressure receiving area in communication with the gas at the suction area and a reference pressure receiving area in communication with the gas in said reference chamber, said pressure sensitive member moving in response to a differential pressure between the reference pressure and the suction pressure;

a member that couples movement of said pressure sensitive member to said discharge valve portion for controlling gas communication between the discharge area and the crankcase chamber; and

a microvalve device for controlling at least one of the flow of the gas from the discharge area to the reference chamber and the flow of the gas from the reference chamber to the suction area in response to electrical signals, thereby establishing the reference pressure.

2. A control valve according to claim 1, further comprising a micromachined pressure sensor in gas communication with the reference chamber, wherein the pressure sensor produces an electrical signal related to the reference pressure, said pressure sensor being integrally formed with the microvalve device.

3. A control valve according to claim 1, wherein the reference chamber is a closed space formed by rigid walls, the reference pressure receiving area of the pressure sensitive member, and a plug upon which the microvalve device is mounted.

4. The control valve according to claim 1 wherein the microvalve device comprises a thermally actuated microvalve.

5. The control valve according to claim 1 wherein the microvalve device comprises a micro spool valve.

6. The control valve according to claim 5 wherein the micro spool valve includes a pilot portion and a pilot operated spool portion.

7. The control valve according to claim 1 wherein the microvalve device comprises:

a 2-way pilot operated microvalve; and

a 4-way pilot microvalve for controlling the 2-way pilot operated microvalve.

8. The control valve according to claim 7 wherein the 4-way pilot microvalve comprises:

a body having an intermediate plate layer with a cavity formed therein, said body defining an inlet connection, an outlet connection, and first and second load connections in fluid communication with said cavity;

a moveable microvalve element disposed in said cavity moveable between a first position and a second position, said moveable element being operable to allow fluid communication between said inlet connection and said first load connection and between said outlet connection and said second load connection when said moveable element is in said first position and being operable to allow fluid communication between said inlet connection and said second load connection and between said outlet connection and said first load connection when said moveable element is in said second position; and

a microvalve actuator operable to move said moveable element between said first position and said second position.

9. The control valve according to claim 7 wherein the 2-way pilot operated microvalve comprises:

a multilayer plate valve body having an intermediate plate layer with a cavity formed therein, said body defining an inlet connection and an outlet connection in fluid communication with said cavity;

a moveable microvalve element disposed in said cavity moveable between a first position and a second position, said moveable element being operable to allow fluid communication between said inlet connection and said outlet connection when said moveable element is in said first position and being operable to block fluid communication between said inlet connection and said outlet connection when said moveable element is in said second position; and

a feedback port formed in the moveable element operable to regulate the pressure on an end of the moveable element relative to the movement of said moveable element between said first position and said second position.

10. The 2-way pilot operated microvalve of claim 9 wherein the moveable microvalve element comprises a spool blocking portion defining a recessed portion, said recessed portion slidably engaging a spool beam attached to layers of said multilayer plate valve body adjacent to said intermediate plate layer.