Electro-pneumatic control valve with microvalve pilot
First Claim
1. An electromechanical control valve for a variable displacement compressor of the type having a piston having a displacement within a compression chamber, the compression chamber admitting gas from a suction area at a suction pressure and discharging gas to a discharge area at a discharge pressure, the compressor having a crankcase which is filled with a gas at a crankcase pressure, the displacement of the piston varying according to the crankcase pressure, the electromechanical control valve controlling the crankcase pressure, the electromechanical control valve comprising:
- a compressor displacement control portion, including;
a discharge pressure valve portion for controlling gas communication between the discharge area and the crankcase chamber; and
a coupling member operatively connected to said discharge valve portion for controlling gas communication between the discharge area and the crankcase chamber;
a variable setpoint control portion including a reference chamber isolated from the crankcase chamber and containing gas at a reference pressure; and
a microvalve device for controlling at least one of the flow of gas from the discharge area to said reference chamber and the flow of gas from said reference chamber to the suction area in response to signals, thereby establishing said reference pressure; and
. a pressure sensitive component disposed between said compressor displacement control portion and said variable setpoint control portion, said pressure sensitive component having a suction pressure receiving area in communication with gas at the suction area and a reference pressure receiving area in communication with gas in said reference chamber, said pressure sensitive component moving in response to a differential pressure between the reference pressure and the suction pressure.
1 Assignment
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Accused Products
Abstract
The invention relates to a MEMS (Micro Electro Mechanical Systems) device in the form of a pressure control valve suitable for controlling the operation of a refrigeration compressor. The pressure control valve is responsive to a reference pressure controlled by a microvalve.
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Citations
15 Claims
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1. An electromechanical control valve for a variable displacement compressor of the type having a piston having a displacement within a compression chamber, the compression chamber admitting gas from a suction area at a suction pressure and discharging gas to a discharge area at a discharge pressure, the compressor having a crankcase which is filled with a gas at a crankcase pressure, the displacement of the piston varying according to the crankcase pressure, the electromechanical control valve controlling the crankcase pressure, the electromechanical control valve comprising:
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a compressor displacement control portion, including;
a discharge pressure valve portion for controlling gas communication between the discharge area and the crankcase chamber; and
a coupling member operatively connected to said discharge valve portion for controlling gas communication between the discharge area and the crankcase chamber;
a variable setpoint control portion including a reference chamber isolated from the crankcase chamber and containing gas at a reference pressure; and
a microvalve device for controlling at least one of the flow of gas from the discharge area to said reference chamber and the flow of gas from said reference chamber to the suction area in response to signals, thereby establishing said reference pressure; and
.a pressure sensitive component disposed between said compressor displacement control portion and said variable setpoint control portion, said pressure sensitive component having a suction pressure receiving area in communication with gas at the suction area and a reference pressure receiving area in communication with gas in said reference chamber, said pressure sensitive component moving in response to a differential pressure between the reference pressure and the suction pressure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A pressure control MEMS device, comprising:
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a control valve adapted to be connected to a source of pressurized fluid, and adapted to be connected to a load, said control valve controlling a path of fluid communication between the source of pressurized fluid and the load;
a structure defining a reference chamber;
a microvalve device connected in fluid communication with said reference chamber to establish a reference pressure in said reference chamber; and
.a pressure sensitive component operatively connected to said control valve;
said pressure sensitive component having a system pressure receiving area adapted to be connected to a fluid system to receive fluid at a system pressure, and a reference pressure receiving area in communication with fluid in said reference chamber at said reference pressure, said pressure sensitive component moving to operate said control valve in response to a difference in pressure between said system pressure and said reference pressure. - View Dependent Claims (11, 12, 13, 14)
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15. An electromechanical control valve for a variable displacement compressor of the type including a piston having a displacement within a compression chamber, the compression chamber admitting gas from a suction area at a suction pressure and discharging gas to a discharge area at a discharge pressure, the compressor also having a crankcase filled with gas at a crankcase pressure, the displacement of the piston varying according to the crankcase pressure, the control valve electromechanical controlling the crankcase pressure, the electromechanical control valve comprising:
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a compressor displacement control portion, including;
a discharge pressure valve portion for controlling gas communication between the discharge area and the crankcase chamber;
a suction pressure valve portion for controlling gas communication between the crankcase chamber and the suction area; and
a coupling member operatively connected to said discharge valve portion for controlling gas communication between the discharge area and the crankcase chamber and operatively connected to said suction valve portion for controlling gas communication between the crankcase chamber and the suction area in such a manner that as the coupling member is moved to open the discharge valve portion, the coupling member is moved to close the suction valve portion and as the coupling member is moved to close the discharge valve portion, the coupling member is moved to open the suction valve portion; and
a variable setpoint control portion including;
a pressure sensitive component operatively controlling the position of said coupling member in response to a difference between the suction pressure and a reference pressure; and
a microvalve arrangement in fluid connection with the discharge area and the suction area and controlling the application of gas to said pressure sensitive component to establish said reference pressure.
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Specification