Variable capacity reciprocating compressor

Patent metadata

Field	Value
Publication number	US-10145372-B2
Application number	US-201615332728-A
Country	US
Kind code	B2
Filing date	Oct 24, 2016
Priority date	Aug 8, 2013
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

A reciprocating compressor may include a shell, a first cylinder, a plate, a second cylinder, and a piston. The first cylinder may be disposed within the shell and may include a first valve. The plate may be fixed relative to the first cylinder and may include a second valve. The second cylinder may be axially aligned with the first cylinder and may be moveable relative to the first cylinder between first and second positions. The piston may be disposed within the second cylinder and may include a third valve. The piston may reciprocate relative to the first and second cylinders. The piston and the plate may define a first compression chamber therebetween. The piston and the first cylinder may define a second compression chamber therebetween. A fluid-injection passage extending through the first cylinder selectively provides a working fluid from a source to the second compression chamber.

First claim

What is claimed is:

1. A reciprocating compressor comprising:
a shell;
a first cylinder disposed within said shell and including a first valve;
a plate fixed relative to said first cylinder and including a second valve;
a second cylinder axially aligned with said first cylinder and moveable relative to said first cylinder between first and second positions;
a piston disposed within said second cylinder and including a third valve, said piston reciprocating relative to said first and second cylinders, said piston and said plate defining a first compression chamber therebetween, said piston and said first cylinder defining a second compression chamber therebetween;
a fluid-injection passage extends through said first cylinder and provides a working fluid to said second compression chamber; and
a fluid-injection valve in said fluid-injection passage is moveable between an open position allowing fluid to be injected into said second compression chamber through said fluid-injection passage and a closed position restricting fluid communication between said second compression chamber and said fluid-injection passage.

2. The reciprocating compressor of claim 1 , wherein motion of said piston toward said plate compresses fluid within said first compression chamber and forces the compressed fluid out of said first compression chamber and into said second compression chamber without exiting said shell.

3. The reciprocating compressor of claim 1 , wherein an inner diametrical surface of the piston slidably and sealingly engages an outer diametrical surface of the first cylinder.

4. The reciprocating compressor of claim 1 , wherein said third valve is movable between a first position restricting communication between said first and second compression chambers and a second position allowing communication between said first and second compression chambers.

5. The reciprocating compressor of claim 1 , wherein an inner diametric surface of said second cylinder includes an opening extending therethrough and communicating with an interior volume of said shell.

6. The reciprocating compressor of claim 5 , wherein said opening in said second cylinder is isolated from said first compression chamber when said second cylinder is in said first position and is allowed to communicate with said first compression chamber when said second cylinder is in said second position.

7. The reciprocating compressor of claim 1 , wherein fluid within said first compression chamber is compressed therein to a first pressure when said second cylinder is in said first position and is compressed therein to a second pressure when said second cylinder is in said second position, said second pressure being lower than said first pressure.

8. The reciprocating compressor of claim 7 , wherein said second cylinder includes an opening in fluid communication with an interior volume of said shell that contains suction-pressure working fluid,
wherein when said second cylinder is in said second position, said opening is in fluid communication with said first compression chamber for a portion of a stroke of said piston, thereby allowing working fluid in said first compression chamber to leak into said interior volume through said opening during said portion of said stroke, and
wherein when said second cylinder is in said first position, said opening is fluidly isolated from said first compression chamber during an entire stroke of said piston, thereby preventing working fluid in said first compression chamber from leaking into said interior volume through said opening.

9. The reciprocating compressor of claim 1 , further comprising a crankshaft driving said piston, said second cylinder moving between said first and second positions independently of motion of said crankshaft.

10. A reciprocating compressor comprising:
a shell;
a first cylinder disposed within said shell and defining a discharge passage;
a second cylinder axially aligned with said first cylinder and moveable relative to said first cylinder between first and second positions;
a piston disposed within said second cylinder and reciprocating relative to said first and second cylinders, said piston and said second cylinder defining a first compression chamber, said piston and said first cylinder defining a second compression chamber;
a first valve disposed within said first cylinder and movable relative to the first cylinder between an open position allowing fluid flow from said second compression chamber through said discharge passage and a closed position restricting fluid flow through said discharge passage;
a second valve disposed within said first compression chamber and movable from a closed position to an open position to allow working fluid into said first compression chamber; and
a third valve disposed within said second compression chamber and movable between an open position allowing fluid flow from said first compression chamber to said second compression chamber.

11. The reciprocating compressor of claim 10 , wherein motion of said piston away from said first cylinder compresses fluid within said first compression chamber and forces the compressed fluid out of said first compression chamber and into said second compression chamber without exiting said shell.

12. The reciprocating compressor of claim 10 , further comprising:
a fluid-injection passage extends through said first cylinder and provides a working fluid to said second compression chamber; and
a fluid-injection valve in said fluid-injection passage is moveable between an open position allowing fluid to be injected into said second compression chamber through said fluid-injection passage and a closed position restricting fluid communication between said second compression chamber and said fluid-injection passage.

13. The reciprocating compressor of claim 10 , further comprising a plate fixed relative to said first cylinder and cooperating with said piston and said second cylinder to define said first compression chamber.

14. The reciprocating compressor of claim 13 , wherein said second valve seals against said plate when said second valve is in said closed position.

15. The reciprocating compressor of claim 10 , wherein an inner diametrical surface of the piston slidably and sealingly engages an outer diametrical surface of the first cylinder.

16. The reciprocating compressor of claim 10 , wherein an inner diametric surface of said second cylinder includes an opening extending therethrough and communicating with an interior volume of said shell.

17. The reciprocating compressor of claim 16 , wherein said opening in said second cylinder is isolated from said first compression chamber when said second cylinder is in said first position and is allowed to communicate with said first compression chamber when said second cylinder is in said second position.

18. The reciprocating compressor of claim 10 , wherein fluid within said first compression chamber is compressed therein to a first pressure when said second cylinder is in said first position and is compressed therein to a second pressure when said second cylinder is in said second position, said second pressure being lower than said first pressure.

19. The reciprocating compressor of claim 18 , wherein said second cylinder includes an opening in fluid communication with an interior volume of said shell that contains suction-pressure working fluid,
wherein when said second cylinder is in said second position, said opening is in fluid communication with said first compression chamber for a portion of a s

Assignees

• Emerson Climate Technologies

Inventors

• Wallis Frank S

Classifications

• F04B7/02

  the valving being fluid-actuated · CPC title

• F04B19/22

  of reciprocating-piston type · CPC title

• F04B39/122

  Cylinder block · CPC title

• F04B39/121

  Casings · CPC title

• F04B49/225

  with throttling valves or valves varying the pump inlet opening or the outlet opening · CPC title