Electrically operated compressor capacity control system with integral pressure sensors

• US 6,732,541 B2
• Filed: 10/09/2002
• Issued: 05/11/2004
• Est. Priority Date: 05/03/2002
• Status: Expired due to Term

• Current Assignee: Mahle International GmbH (MAHLE-STIFTUNG GmbH)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Barnes, Michael S., Jackson, Andrew J., Gutierrez, Ernesto Jose, Urbank, Thomas Martin, Sangwan, Karma Vir
• Primary Examiner(s): NORMAN, MARC E
• Application Number:
  US10/267,725
• Publication Number:
  US 20030029180A1
• Time in Patent Office: 580 Days
• Field of Search: 622/283, 622/285, 417/222.2, 417/222.1, 417/269, 417/270, 417/213, 74/60
• US Class Current: 62/228.3
• CPC Class Codes: F04B 2027/1813 Crankcase pressure
• CPC Class Codes: F04B 2027/1827 between crankcase and discharge chamber
• CPC Class Codes: F04B 2027/185 Discharge pressure
• CPC Class Codes: F04B 2027/1859 Suction pressure
• CPC Class Codes: F04B 2027/1895 between crankcase and suction chamber
• CPC Class Codes: F04B 2205/02 Pressure in the inlet chamber
• CPC Class Codes: F04B 2205/04 Pressure in the outlet chamber
• CPC Class Codes: F04B 27/1804 Controlled by crankcase pressure

Abstract

A capacity control system for a variable capacity refrigerant compressor includes an internal bleed passage coupling a crankcase chamber of the compressor to a suction port, an electrically-operated two-port control valve that selectively opens and closes a passage between the crankcase chamber and a discharge chamber, and pressure sensors for measuring the compressor discharge pressure and suction pressure. A plunger of the control valve is disposed within the passage coupling the crankcase chamber and the discharge chamber, and a solenoid armature linearly positions the plunger within the passage to open and close the passage. The plunger has an axial bore that forms a continuous passage between the discharge chamber and a cavity in which the discharge pressure sensor is retained so that the sensor is continuously exposed to the discharge pressure regardless of the plunger position.

Claims

1. Capacity control apparatus for a refrigerant compressor having a pumping capacity that varies according to a refrigerant pressure in a crankcase chamber thereof, the compressor additionally having a refrigerant inlet chamber and a refrigerant outlet chamber, the capacity control apparatus comprising:

a refrigerant bleed passage for continuously permitting refrigerant flow from said crankcase chamber to said inlet chamber;

a two-port control valve that selectively opens and closes a passage between the crankcase and outlet chambers for permitting the refrigerant pressure in the crankcase chamber to increase toward a discharge pressure in said outlet chamber;

a discharge pressure sensor integrated with said control valve for measuring said discharge pressure; and

a suction pressure sensor integrated with said control valve for measuring a refrigerant pressure in said inlet chamber.

2. The capacity control apparatus of claim 1, wherein the control valve includes a plunger partially disposed within the passage coupling the crankcase and outlet chambers that is axially positioned to open and close the passage, said plunger having an axial bore that partially defines a continuous passage between the outlet chamber and a discharge sensor cavity to which said discharge pressure sensor is coupled so that said discharge pressure sensor is continuously exposed to said discharge pressure regardless of the plunger position.

3. The capacity control apparatus of claim 2, where the control valve includes a housing member defining said discharge sensor cavity and a passage coupling said discharge sensor cavity to a chamber in which an outboard end of said plunger is disposed, said housing member additionally defining a stop for limiting outboard movement of said plunger.

4. The capacity control apparatus of claim 3, wherein said housing member additionally includes a suction sensor cavity for said suction pressure sensor and a passage coupling said suction sensor cavity to said inlet chamber.

5. The capacity control apparatus of claim 1, wherein the control valve comprises:

a plunger partially disposed within the passage coupling the crankcase and outlet chambers that is axially positioned to open and close the passage; and

an electrically activated solenoid including a permanent magnet pole piece disposed about said plunger, and a moving coil armature affixed to said plunger such that activation of said moving coil armature produces a magnetic force for axially positioning said plunger.

6. The capacity control apparatus of claim 5, wherein said magnetic force positions said plunger to close the passage coupling the crankcase and outlet chambers so that said bleed passage allows the refrigerant pressure in said crankcase chamber to bleed down toward a suction pressure in said inlet chamber, and said control valve includes a spring for positioning said plunger to open the passage coupling the crankcase and outlet chambers in an absence of said magnetic force so that the refrigerant pressure in said crankcase chamber increases toward said discharge pressure.

7. The capacity control apparatus of claim 1, wherein the control valve comprises:

a plunger partially disposed within the passage coupling the crankcase and outlet chambers that is axially positioned to open and close the passage;

a first stop disposed in said passage coupling the crankcase and outlet chambers to define a first limit position of said plunger; and

a second stop defining a second limit position of said plunger.

8. The capacity control apparatus of claim 1, wherein the control valve comprises:

a pressure port having an axial bore defining said passage;

a plunger partially disposed within the axial bore of said pressure port and axially positionable therein to open and close said passage; and

balance grooves formed on an exterior periphery of said plunger within said axial bore for laterally balancing said plunger within said axial bore.