TWO-STAGE ROTARY COMPRESSOR

• US 20090035166A1
• Filed: 07/30/2007
• Published: 02/05/2009
• Est. Priority Date: 07/30/2007
• Status: Active Grant

• Current Assignee: Tecumseh Products Company
• Original Assignee: Tecumseh Products Company
• Inventors: Newland, Joseph A.
• Granted Patent: US 7,866,962 B2
• Time in Patent Office: Days
• US Class Current: 418/13
• CPC Class Codes: F04C 18/3564 the surfaces of the inner and outer member, forming the working space, being surfaces of revolution
• CPC Class Codes: F04C 23/001 of similar working principle
• CPC Class Codes: F04C 23/008 Hermetic pumps

Abstract

A two-stage rotary compressor having a compression mechanism including a single muffler housing member. The single muffler housing member at least partially defines an intermediate pressure discharge cavity and a discharge pressure discharge cavity. In one exemplary embodiment, the compression mechanism includes a cylinder block having a plurality of vanes positioned within slots formed in an inner cylindrical surface of the cylinder block. The slots are in fluid communication with the discharge pressure discharge cavity and receive discharge pressure working fluid to bias the vanes radially inwardly. In another exemplary embodiment, the cylinder block includes a plurality of passages for the delivery of working fluid to and from the cylinder block.

Claims

1. A rotary compressor, comprising:

a motor;

a crankshaft operably coupled to said motor whereby operation of said motor rotates said crankshaft, said crankshaft having an eccentric portion;

a roller positioned on said eccentric portion, said roller defining an outer cylindrical surface;

a cylinder block having an inner cylindrical surface including a plurality of slots formed therein, said inner cylindrical surface defining a substantially cylindrical cavity, said eccentric portion of said crankshaft being rotatably disposed within said cylinder block, wherein said outer cylindrical surface of said roller contacts said inner cylindrical surface of said cylinder block;

a first vane positioned at least partially within one of said plurality of slots of said cylinder block, said first vane biased inwardly to contact said outer cylindrical surface of said roller;

a second vane positioned at least partially within another of said plurality of slots of said cylinder block, said second vane biased inwardly to contact said outer cylindrical surface of said roller;

a first compression chamber defined by said first vane, said second vane, said cylinder block, and said roller, in which a working fluid is compressed from a suction pressure to an intermediate pressure;

a second compression chamber defined by said first vane, said second vane, said cylinder block, and said roller, in which a working fluid is compressed from the intermediate pressure to a discharge pressure; and

a single muffler housing member at least partially defining an intermediate pressure discharge cavity and a discharge pressure discharge cavity, said intermediate pressure discharge cavity in fluid communication with said first compression chamber and said discharge pressure discharge cavity in fluid communication with said second compression chamber.

2. The rotary compressor of claim 1, further comprising a main bearing at least partially defining said intermediate pressure discharge cavity and said discharge pressure discharge cavity.

3. The rotary compressor of claim 2, wherein said main bearing and said single muffler housing member define the entirety of said intermediate discharge pressure cavity and said discharge pressure discharge cavity.

4. The rotary compressor of claim 1, further comprising a hermetic housing defining an interior, wherein said intermediate pressure discharge cavity is in fluid communication with said interior of said hermetic housing.

5. The rotary compressor of claim 1, wherein said main bearing further comprises a plurality of passageways, each of said plurality of passageways in fluid communication with a respective one of said plurality of slots in said cylinder block.

6. A rotary compressor, comprising:

a motor;

a crankshaft operably coupled to said motor whereby operation of said motor rotates said crankshaft, said crankshaft having an eccentric portion;

a roller positioned on said eccentric portion, said roller defining an outer cylindrical surface;

a cylinder block having an inner cylindrical surface including a plurality of slots formed therein, said inner cylindrical surface defining a substantially cylindrical cavity, said eccentric portion of said crankshaft being rotatably disposed within said cylinder block, wherein said outer cylindrical surface of said roller contacts said inner cylindrical surface of said cylinder block;

a first vane positioned at least partially within one of said plurality of slots of said cylinder block, said first vane biased inwardly to contact said outer cylindrical surface of said roller;

a second vane positioned at least partially within another of said plurality of slots of said cylinder block, said second vane biased inwardly to contact said outer cylindrical surface of said roller;

a first compression chamber defined by said first vane, said second vane, said cylinder block, and said roller, in which a working fluid is compressed from a suction pressure to an intermediate pressure;

a second compression chamber defined by said first vane, said second vane, said cylinder block, and said roller, in which a working fluid is compressed from the intermediate pressure to a discharge pressure;

a main bearing at least partially defining a discharge pressure discharge cavity in fluid communication with said second compression chamber; and

a plurality of passages in respective fluid communication with said discharge pressure cavity and with said plurality of slots of said cylinder block, wherein during operation of the compressor, working fluid at discharge pressure is communicated from said discharge cavity to said plurality of slots of said cylinder block to bias said vanes into engagement with said outer cylindrical surface of said roller.

7. The rotary compressor of claim 6, wherein said plurality of passages extend through said main bearing.

8. The rotary compressor of claim 6, further comprising a muffler housing member at least partially defining said discharge pressure discharge cavity, wherein said muffler housing member and said main bearing define the entirety of said discharge pressure discharge cavity.

9. The rotary compressor of claim 6, further comprising a discharge outlet in fluid communication with said discharge pressure discharge cavity.

10. The rotary compressor of claim 9, wherein said discharge outlet extends through said cylinder block.

11. A rotary compressor, comprising:

a motor;

a crankshaft operably coupled to said motor whereby operation of said motor rotates said crankshaft, said crankshaft having an eccentric portion;

a roller positioned on said eccentric portion, said roller defining an outer cylindrical surface;

a cylinder block having an inner cylindrical surface including a plurality of slots formed therein, said inner cylindrical surface defining a substantially cylindrical cavity, said eccentric portion of said crankshaft being rotatably disposed within said cylinder block, wherein said outer cylindrical surface of said roller contacts said inner cylindrical surface of said cylinder block;

a first vane positioned at least partially within one of said plurality of slots of said cylinder block, said first vane biased inwardly to contact said outer cylindrical surface of said roller;

a second vane positioned at least partially within another of said plurality of slots of said cylinder block, said second vane biased inwardly to contact said outer cylindrical surface of said roller;

a first compression chamber defined by said first vane, said second vane, said cylinder block, and said roller, in which a working fluid is compressed from a suction pressure to an intermediate pressure;

a second compression chamber defined by said first vane, said second vane, said cylinder block, and said roller, in which a working fluid is compressed from the intermediate pressure to a discharge pressure;

a suction pressure inlet extending through said cylinder block and in fluid communication with said first compression chamber;

an intermediate pressure inlet extending through said cylinder block and in fluid communication with said second compression chamber; and

an outlet extending through said cylinder block and in fluid communication with one of said first compression chamber and said second compression chamber.

12. The rotary compressor of claim 11, wherein said outlet is in fluid communication with said second compression chamber.

13. The rotary compressor of claim 11, wherein said outlet is in fluid communication with said first compression chamber.