US2306813A - Compressor - Google Patents

Description

Dec. 29, 1942 E. KING 2,306,813

7 COMPRESSOR I Filed Sept. 16, 1941 Inventor: Ralph E. King,

His AttoTney' Patented Dec. 29, 19 42 COMPRESSOR Ralph E. King, Fort Wayne, Ind., assignor to General Electric Company, a corporation of New York Application September 16, 1941, Serial No. 411,036

6 Claims.

My invention relates to compressors and particularly to compressors provided with devices for separating oil from the working fluid admitted to the compressor.

Compressors operating in systems such as refrigerating machines which have closed circuits tl.rough which the'working fluid is circulated unavoidably entrain small quantities of the lubricating oil in the working fluid. In order to mainscription proceeds, and the features of novelty whichcharacterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention reference may be had to the accompanying drawing in which Fig. 1 shows a partial elevational view in section of a refrigerant compressor embodying my invention; and Fig. 2 is 1 a diagrammatic view of the compressor of Fig. 1

arranged in a refrigerating system.

Briefly, the compressor shown in the drawing comprises a cylinder block having a reciprocat ing piston mounted therein and a crankcase for holding a quantity. of lubricating oil. The 28. Thehead 2| has formed therein acha'mber compressor is provided with a valve plate and 29 about the intake port Manda second cham a head providing the intake and exhaust pasber 30 separated from the chamber 295 by a sages and valves for the compressor cylinder wall 3| and communicating with the -chamber in which the piston is mounted. In order to 29 through a restricted opening 32 in the wall I 3|. The chamber 30 is arranged'to receive-workseparate oil from the working fluid drawn into compressor two parallel paths are provided between the suction connection of the compressor-and the intake port of the cylinder. An oil separating chamber is arranged at the entrance of the two chambers and one path. leads directly to a chamber at the intake port of the compressor while the other leads through the crankcase. Most of the oil separated from the working fluid is directed so that it flowsthrough the path leading through the crankcase and the oil is trapped and retained in the crankcase while the working fluid flows to the intake port.

Referring now to the drawing,'the compressor shown in Fig. 1 comprises a block l0 having tain the desired quantity of lubricant in the a crankcase ll formed integra y therewithcompressor crankcase and also to prevent lower- Only a portion of the crankcase has been shown ing of the effective capacity of the working in Fig. 1. However, its outline is indicated in fluid, it is necessary to separate the lubricant Fig. 2 and its construction is in accordance with from the working fluid and return it to the well-known practice. A cylinder I2 is formed in crankcase. Many different arrangements have the block l0 and a ecip o a piston or been provided for this purpose. 7 placement member I3 is mounted therein. The It is an object of my invention to provide a. piston is actuated by rotation of a shaft I4 driven compressor having an improved arrangement for by a su table motor (not Shown) ou a Crank separating and returning to the crankcase lubripm Hi and a co n joined to the eating oil which has become entrained in the piston by means of a Suitable Wrist-Din working fluid returned to the compressor. counterweight I8' is provided to balance the Another object of my invention is to provide compressor and a splashing'element or finger IS a compressor having an improved oil return is secured. to the counterweight to dip into a device of simple and rugged construction which body of oil in the bottom of the crankcase and may be arranged entirely within the compressor splash oil to the working parts of the mechaand is effective to return to the crankcase a nism. The shaft I l, as shown in the drawing, high proportion of the lubricating oil entering is intended to be rotated in a counterclockwise the compressor intake with the working fluid. direction. The counterweight l8 and the finger Further objects and advantages of my inven- 19 are displaced axially to the rear of the contion will become apparent as the following denecting rod, as viewed in Fig. 1, so that they can- 'not strike the walls of the cylinder l2. The

compressor is provided with a valve plate 20 and a head 2|. Gaskets 22-are provided on either side of the valve plate, and thehad and valve plate are secured to the block by a plurality of cap screws 23. The valve plate'is provided with an intake port 24. and an intake valve 25 of the flexible 'reed type is securely held between the plate and the block to; control the port 24. Suitable pins 26 may befemplcyed to position the valve 25 securely. An"'exh'aus't port 21 is formed in the valve plate 20 i'nc'olnmunication with the cylinder li a'rld is controlled by a suitable exhaust valve indicated at suction connection being provided with a suitable fine mesh wire screen or filter toprevent foreign matter fromentering thetcompressor. The head 2| is provided withan ex haust chamber 35 in communication with the exhaust port 21 .and arranged to discharge working fluid from the compressor through an exhaust passage 36 in an exhaust or discharge connection 31.

The arrangement of the chamber 30 and the restricted opening 32 is such that considerable turbulence of the working fluid drawn into the compressor occurs in the chamber 30 and lubricating oil entrained in the working fluid is separated and falls to the bottom of the chamber. This lubricant may be returned to the crankcase through a suitable duct 38 formed in the block l and in the plate 20. In order to cause a positive flow downwardlv through the duct 38, I provide a second duct 39 in the block "I and valve plate 20 in communication with the chamber 29 at its upper end and with the crankcase at its lower end. A suitable tube 40 may be inserted in the lower end of the duct 39 and the end thereof bent toward the side of the crankcase so that its open end, indicated at 4|, is in the same direction as the direction of movement of the splashing element l9, and the tendency of oil to be splashed into the opening 4| is minimized. The extension tube 40 is not, however, necessary to the satisfactory separation of the oil from the gaseous refrigerant entering the cylinder.

The duct 39 is preferably made of a larger cross-sectional area than the duct38 to facilitate the drawing of working fluid through the duct 33 into the crankcase and thence into the duct 39 to the chamber 29. This provides a parallel path for the flow of gaseous working fluid from the suction connection 33 to the chamber 29. Most of the working fluid flows from the connection 33-to the chamber 29 through the chambers 29 and 30 and the opening 32 in series communication. The positive flow of fluid through the duct 38 draws into the crankcase the lubricant separated from the working fluid in the chamber 30 This lubricant is trapped in the crankcase while the working fluid .flows from the crankcase to the chamber 29 through the duct 39. This construction provides a'simple and effective device for separating lubricant from the working fluid admitted to the compressor and ing svstem as indicated in Fig. 2. The discharge connection 31 is secured to a connector 42 of a discharge line by which the hot compressed refri erant is conduc ed to a condenser 43. The refrigerant in the condenser 43 is cooled and liquefied by operation of a fan 44 driven by an electric mo or 45. and the liquid refrigerant is delivered to a receiver 46. From the receiver 46 the refrigerant flows to an evaporator 41 under the controlof a thermostatic expansion valve 43 having its thermal element 49 in heat exchange with the outlet or suction line 50 of the evaporator. The vaporized refri erant is returned to the compressor through the suction line 50 which is secured by a suitable connector to the suction connection of the compressor.

During the operation of the'refrigerating system shown in 'Fig. 2 a certain amount of the lubricant in the crankcase l unavoidably enters the cylinder of the compressor because of the.

pumping action of the piston which forces the oil or lubricant along the cylinder walls, and this lubricant is entrained with the refrigerant discharged to the condenser and flnds its way to the evaporator and eventually is returned to the compressor intake through the suction line 50. The greater part of the lubricant which enters the compressor head with the refrigerant is separated from the vaporized refrigerant in the chamber 30 of the compressor and flows from the chamber 30 through the duct 38 to the crankcase. The greater portion of the vaporized refrigerant flows to the chamber 29 and the intake port 24 through the'restricted opening 32, and the portion of the gaseous refrigerant flowing through the crankcase reaches the chamber 29 and the intake port 24 through the duct 39.

From the foregoing it is readily apparent that I have provided a simple and effective arrangement for separating lubricating oil from the working fluid admitted to the compressor and for returning the oil to the crankcase. This arrangement requires no additional working parts and no complicated structure and may be built easily into the head of the compressor.

While I have described my invention in connection with a refrigerant compressor, other applications will readily be apparent to those skilled in the art. I do not therefore desire my invention to be limited to the particular construction shown and described, and I intend in the appended'claims to cover all modifications within R the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. A compressor having a crankcase, working fluid suction and exhaust connections for said compressor, said compressor having a cylinder and a displacement member therein, means providing intake and exhaust ports and valves therefor, means providing two parallel paths for the flow of gaseous working fluid from said suction connection to said intake port, one. of said paths including said crankcase, and means adjacent the inlet of said one of said parallel paths for separating lubricant from the working fluid flowing from said suction connection to said paths and for directing the lubricant into said one path whereby lubricant entrained in the working fluid entering said suction connection is returned to said crankcase.

2. A compressor having a crankcase, workin fluid suction and exhaust connections for said compressor, said compressor having a cylinder and a displacement member therein, means providing an intake port and an exhaust port for said cylinder and valves therefor, means providing a first chamber adjacent and in communication with said intake port, means providing a second chamber between said first chamber and said suction connection and a restricted opening between said chambers, means providing ducts between said chambers and said crankcase, the duct between said flrst chamber and said crankcase having a larger cross-sectional area than the duct between said second chamber and said crankcase whereby a portion of the working fluid entering said second chamber flows to said flrst chamber through said crankcase and oil carried thereby is separated therefrom and retained in said crankcase.

3. A compressor comprising a block having a cylinder and a working fluid displacement member therein and a crankcase for holding a body of lubricating 011, said cylinder having intake and exhaust ports, valves for said ports, intake and exhaust. connections for said compressor, means providing two chambers connected in series communication between said intake connection and said intake port to provide a. first path for gaseous working fluid flowing from said intake connection to said intake port, means providing ducts connecting both of said chambers with said crankcase to provide a second path for gaseous working fluid flowing from said intake connection to said intake port, said paths being so arranged that portion of the gaseous working fluid flow from said intake connection through said paths in parallel to said intake port whereby oil entrained in the portion of the working fluid flowing through said second path is retained in said crankcase.

4. A. compressor comprising a block having a cylinder and a working fluid displacement member therein and a crankcase for holding a body of lubricating oil, said cylinder having intake and exhaust ports, valves for said ports, intake and exhaust connections for said compressor, a head for said compressor havinga chamber formed therein about said intake port, means providing communication between said chamber and said crankcase, said head having a second chamber formed therein and arranged in communication with said intake connection and with said first mentioned chamber for separating oil from the gaseous working fluid flowing from said intake connection to said intake port, means providing communication between said second chamber and said crankcase whereby a portion of the gaseous working fluid flowing to said intake port passes to said flrst mentioned chamber through said crankcase and oil separated from the working fluid in said second chamber flows to said crankcase and is trapped therein.

5. A compressor comprising a cylinder block and a crankcase, said cylinder block having a cylinderand a reciprocating piston mounted therein, a valve plate having intake and exhaust ports for said cylinder, valves for said ports, a head for said compressor having intake and exhaust con nections, said head having two chambers formed therein and having a restricted opening providing communication between said chambers one of said chambers being in direct communication with said intake port and the other of said chambers being in direct communication with said intake connection, said block and said valve plate having a first duct formed therein providing communication between said crankcase and said other chamber and a second duct providing communication between said crankcase and said one chamber, said other chamber being so arranged and constructed as to facilitate the separation of oil from the refrigerant in the Working fluid entering said compressor, the major portion of the working fluid flowin to said intake portpassing through said restricted opening and the remaining portion passing through said ducts and said crankcase whereby oil separated from the working fluid in said other chamber is trapped in said crankcase.

6. A compressor comprising a cylinder block and a crankcase, said. cylinder block having a cylinder and a reciprocating piston mounted therein, means including a rotating member having a crank pin thereon and a connecting rod between said crank pin and said pistontfor reciprocating said piston, an oil splashing element secured to said rotating member for directing oil to the working parts of said compressor, a valve plate having intake and exhaust ports for said cylinder, valves for said ports, a head for said compressor having intake and exhaust connections, said head having two chambers formed therein and having a restricted opening providing communication between said chambers, one of said chambers being in direct communication with said intake port and the other of said chambers being in direct communication with said intake connection, said block and said valve plate having a first duct formed therein providing communication between said crankcase and said other chamber and a second duct providing communication between said crankcase and said one chamber, an intake tube communicating with said second duct for conducting working fluid to said'second duct from said crankcase, said tube having its open end turned toward one side of said crankcase in the same direction as that of the movement of said splashing element whereby the tendency to splash oil into said tube is minimized, said other chamber being so arranged and constructed as to facilitate the separation of oil from the refrigerant in the working fluid entering said compressor, the major portion 01' the working fluid flowing to said intake port passing through said restricted opening and the remaining portion passing through said ducts and said crankcase whereby oil separated from the working fluid in said other chamber is trapped in said crankcase.

RALPH E. KING.

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