US2150487A - Compressor apparatus - Google Patents

Description

I March 14, 1939. 5. BROWN 2,150,487

COMPRESSOR APPARATUS Filed June 4, 1938 INVENTOR Jay/flour fir'oa/zz ATTO R N EY lubrication is employed, the presence of ade- Patented Mar. 14, 1939 PATENT OFFICE COMPRESSOR APPARATUS Seymour Brown, Syracuse, N. Y., assignor to Carrler Corporation, Syracuse, N. Y., a corporation of Delaware Application June 4, 1938, Serial. No. 211,788

9 Claims.

This invention relates to compressor appara-- pressor is subsequently placed in operation, this refrigerant leaves the crankcase during equalization of crankcase and suction pressures and necessarily carries with it' considerable quantities of the oil by which it has been absorbed.

This results in insufllcient lubrication of the compressor,since whether splash or forced-feed quate quantities of oil in the crankcase of the compressor is essential to proper lubrication. Often irreparable damage is done to the compressor by reason of the insumcient lubrication during the starting-up period.

An object of the invention is to provide an apparatus for facilitating equalization of crankcase and suction pressures during starting-up periods, thereby to shorten such periods, and for thereafter, during an operating period, maintaining the pressure of the crankcase at a lower level than the pressure obtaining in the suction side of the compressor. The maintenance of such a pressure differential serves to provide for the return of oil from the system to the crankcase and for the retention of such oil in the crankcase, thus to assure adequate and proper lubrication of the compressor.

Another object of the invention is to provide means for preventing the delivery to the compressor of a refrigerating system of unevaporated particles of refrigerant passing from the evaporator of the system and, during the starting-up period, from the crankcase of thecompressor.

- A feature of the invention resides in providing, in conjunction with the suction line or intake of the compressor of a refrigerating system,

' means for increasing the velocity and reducing the pressure \of refrigerant passing to the compressor, and a tube or the like, providing communication between the crankcase of the compressor and the low pressure area thus created in the compressor suction line. Such-pressure-reducing means in the suction line may comprise, for example, a venturi, nozzle or orifice arrangement. The low pressure thus created in the gas suction line serves to create in the crank case a pressure which is lower than that of the suction line feeding the compressor, so that after the starting-up period of operation oil is prevented from leaving the crankcase and is, in fact, returned to the crankcase from the remainder of the system. Since at all times during the operation of the compressor subsequent to the starting-up period this arrangement pro-, vides for maintaining the pressure in the crankcase lower than the pressure in the suction line, the circulation of oil through the refrigerating system is much reduced and practically eliminated. Thus, small quantities of oil may be used with greater assurance of adequate lubrication throughout all portions of the operating periods. Further, due to the retention of the major portion of the oil in the crankcase, larger quantities of oil may be utilized than in conventional apparatus, with no increased circulation'of oil throughout the system, as would oc-. cur if larger oil quantities were used in conventional apparatus.

Also, the low pressure area formed in the gas suction line serves to facilitate evaporation-of whatever particles of liquid refrigerant may be drawn through the gas suction line from the evaporator or from the crankcase during starting-up periods. This prevents slugging of the compressor, which has been found especially troublesome in refrigerating systems of the compression type, particularly during the starting-up periods of operation.

Other objects, features and advantages of th invention will be more apparent from the following description to be read in conjunction with the accompanying drawing, in which:

Fig. 1 diagrammatically represents, in vertical section, a compressor apparatus embodying the invention;

Fig. 2 is a fragmentary view on an enlarged scale of a portion of the apparatus of Fig. 1;

Fig. 3 is a fragmentary view similar to Fig. 2 illustrating a modification of the invention, and

Fig. 4 is a fragmentary view similar to Fig. 2 illustrating still another modification of the invention.

Referring now to the drawings, the numeral Ill designates generally a compressor having a casing H, a piston l2 and a crankcase [3, the

bottom of crankcase I 3 serving as an oil reservoir, the oil in crankcase l3 being indicated at ll. Piston I2 is driven through connecting rod l6 by crankshaft l6, which is driven in any suitable manner, as by an electric motor or the like (not shown). Fluid to be compressed is supplied to the compressor l0 through suction line H and compressed fluid is discharged from the compressor through discharge line l8. Upon downward movement of the piston l2 fluid'is intaken within the body of the piston l2 through ports I! and is delivered through passages 20 to the compression chambendesignated 2|, upon opening of suction valve 22. Upon upward movement of the piston l2 the compressed fluid is discharged into discharge chamber 23 upon opening of discharge valve '24, the compressed fluid then passing to discharge line I 6.

In the suction line H is formed a venturi 25 having a throat-portion designated 25a. As fluid is drawn through the suction line l1 and passes through throat portion 26a of the venturi, its velocity is increased and its pressure is reduced, in accordance with well-understood principles. The pressure reduction which thus occurs serves to facilitate evaporationof such liquid particles of refrigerant 'as may remain unevaporated by heat exchange in the evaporator (not shown) from which the suction line H supplies refrigerant to the compressor. Since such liquid'particles areprevented from passing to the compressor, assurance is thus provided against slugging of the compressor due to the presence of liquid refrigerant drawn from the evaporator.

Tube 26 provides communication between the crankcase l3, from a point above the normal oil .level therein, and the area of low pressure proximate the throat of the venturi 25. As shown in Fig. 2, the tube 26 may communicate with the venturi 25 at a point slightly beyond the most constricted portion of the venturi or, ii desired, may be connected to that portion of the venturi which is most constricted. Upon operation of the compressor, the flow of fluid through suction line 81- and through venturi 25 draws a relatively low pressure in the crankcase It, so that the pressure in the crankcase is always lower than the pressure in the suction line IT. The relatively low pressure which is thus caused to be maintained in the crankcase serves to prevent the oil of the crankcase from passing into other parts of the refrigerating system, and to eiIect the return to the crankcase of oil which may be distributed throughout the system, and thus such oil may be eflleiently utilized to provide desired lubrication of the compressor. To prevent splashed oil particles from entering within the tube 26 there is preferably provided a guard baille or the like, 21, of any suitable design positioned over and protecting the lower end of tube 26.

' In Fig. 3 is illustrated a modification of the invention in which the venturi 25 is replaced by a restricting member 26 provided with an orifice opening 29. The opening 29 is relatively small and hence fluid flowing through the suction line I] and the opening 29 travels past the upper extremity of tube 26 at relatively high velocity, thus creating a low pressure area at the upper extremity of the tubing 26 which serves to reduce the pressure in crankcase I3 in the manner explained above.

In Fig. 4. is illustrated another modification of the invention in which the same principle of operation is employed. In Fig. 4 a nozzle 36 is provided for increasing the velocity of flow of fluid passing to the compressor through suction line i 1, and the nozzle 30 is so arranged that its discharge end is proximate and surrounds the upper extremity of tube 26a. The low pressure area created at the upper end of tube 26a. by the high velocity discharge from nozzle 36 serves to maintain the pressure in the crankcase 13 at a relatively low value.

During starting-up periods, oil and refrigerant are drawn from the crankcase through tube 26. When such refrigerant, in the form of liquid particles, passes into the low pressure area proximate the venturi 25 or the like, these particles of refrigerant are vaporized, and slugging" is thus avoided.

While the invention has been described with particular reference to a compressor of the reciprocating type, it will be apparent that the invention may be employed in conjunction with other types of compressors without departing from the scope of the invention.

Since many changes may be made in the invention without departing from its scope, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative only and not in a limiting sense, applicant limiting himself only as indicated in the appended claims.

I claim: I

1. In a compressor apparatus including fluid compression means, a fluid supply line and a crankcase, the combination of means for creating within said fluid supply line an area in which the pressure is substantially lower than the suction pressure of said compression means, and means for providing communication between said area of low pressure and said crankcase at a point above the normal oil level therein.

2. In a compressor apparatus including fluid compression means, means for supplying fluid to be compressed to said compression means, and an oil reservoir having a normal 011 level, the

combination of means for creating within said fluid supply means an area in whichthe pressure is substantially lower than the suction pressure of said compression means, and means for providing communication between-said area of low pressure and said oil reservoir at a point above for forming an area in which the pressure is substantially lower than the suction pressure of said compressor, and means providing communication between said area of low pressure and said crankcase at a point above the normal oil level therein.

4. In combination with a compressor apparatus having an oil reservoir formed in the crankcase thereof and means for supplying to said compressor fluid to be compressed, means operative respcnsive to the supply of fluid to said compressor for forming an area in which the pressure is substantially lower than the suction pressure of said compressor, and a conduit providing communication between said area of low pressure and said crankcase at a point above the normal oil level therein.

5. In combination with a compressor apparatus having an oil reservoir formed in the crankcase thereof and means for supplying to said compressorfluid to be compressed, means operative responsive to the supply of fluid to said compressor for forming an area of lower pressure than the suction pressure of said compressor apparatus, said last-mentioned means comprising a venturi forming a part of said fluid supply means, and a conduit providing communication between said area of low pressure and said crankcase at a point above the normal oil level therein.

6. In combination with a compressor apparatus having an oil reservoir formed in the crankcase thereof and means for supplying to said compressor fluid to be compressed, means operative responsive to the supply of fluid to said compressor for forming an area of lower pressure than the suction pressure of said compressor apparatus, said last-mentioned means comprising a venturi forming a part of said fluid supply means,

and means forming a passageway providing communication between the crankcase of said compressor, at a point above the normal oil level therein, and the fluid supply means proximate the throat of said venturi.

7. In combination with a compressor apparatus having an oil reservoir formed in the crankcase thereof and means forsupplying to said compressor fluid to be compressed, means operative responsive to the supply of fluid to said a compressor for forming an area of lower pressure than the suction pressure of said compressor apparatus, said last-mentioned means including means for restricting communication between upstream and downstream portions of said fluid supply means, whereby fluid passing to the compressor will attain a relatively high velocity proximate said communication-restricting means and thus form an area of relatively low pressure proximate the downstream side of said communication-restricting means, and means forming a passageway providing communication between said area of relatively low pressure and the crankcase of said compressor above the normal oil level.

8. In combination with a compressor apparatus having an oil reservoir formed in the crankcase thereof and means for supplying to said compressor fluid to be compressed, means oper- 9. In combination with a compressor apparatus having an oil reservoir formed in the crankcase thereof and means for supplying to said compressor fluid to be compressed, means operative responsive to the supplyof fluid to said compressor for forming an area in which the pressure is substantially lower than the suction pressure of said compressor apparatus, said lastmentioned means includinga nozzle formation through which fluid passing from the upstream portions of said fluid supply means to the downstream portions thereof is routed, and means forming a passageway communicating between the area of relatively low pressure formed proximate the discharge end of said nozzle formation and the crankcase of said compressor above the normal oil level therein.

. SEYMOUR BROWN.

DISCLAIMER 2,150,487.Seymom' Brown, Syracuse, New York. COMPRESSOR APPARATUS. Patent dated March 14, 1939. Disclaimer filed July 26, 1940, by the assignee, Carrier Corporation. Hereby enters this disclaimer to claims 1, 2, 3, 4, 5, 6 and 7 of said Letters Patent.

[Ofiic'ial Gazette August 27, 1940.]

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