US2298749A

US2298749A - Refrigerating mechanism

Info

Publication number: US2298749A
Application number: US362823A
Authority: US
Inventors: Oskar H Buschmann
Original assignee: Copeland Refrigeration Corp
Current assignee: Copeland Refrigeration Corp
Priority date: 1940-10-25
Filing date: 1940-10-25
Publication date: 1942-10-13
Anticipated expiration: 1959-10-13

Description

Ocf- 13 1942 o. H. BuscHMANN. "2;293749 REFRIGERATING MECHANISM Filed oct. N25, 1940 ashun-sheet 1 l INVENTOR 0L 13, 1942 o. H. BuscHMANN 2,298,749 REFRIGERATING MECHANISM Filed oct. 25, 1940 2 sheets-sheet 2 INVENTOR ATToRN &

Patent'ed Uct. 13, 1942 REFRIGERATING MCHANISM Oskar H. Buschmann, Sidney, Ohio, assignor to Copeland Refrigeration Corporation, Sidney, Ohio, a. corporation o! Michigan i .Application October 25, 1940, Serial No. 362,823

14 Claims.

This invention relates to refrigerating mecha` nism and particularly to a sealed motor compressor unit, the principal object lbeing the provision of a device of the type described having certain new and novel features of construction. Objects of the invention include the provision e of a novel lubricating mechanism for a sealed motor compressor unit; the provision of" novel means for maintaining the axial position of the shaft and rotor assembly of a motor compressor unit; the provision' of a novel construction for a pocket for collecting oil thrown about by the throw, the motor shaft being hollow and a shoulvdered tube communicating with a pocket projecting into the interior of the shaft, a Washer substantially iitting the tube being interposed between the shoulder onthe tube and the end of the shaft whereby to limit movement of the shaft in one direction, and spring means constantly urging the washer against the end of the shaft whereby to minimize the escape of oil from the interior of -the shaft about the exterior of the tube. v

vision of means for quieting the operation of a refrigerant or other compressor; the provisin if of means in a refrigerating mechanism for minimizing the noise accompanying the discharge of means for use in arefrigerantcircuit; and the provisionof a mufiiing means for a gas circuit A subjected to intermittent impulses comprising a 4 coil of closely wound spring wire closed at one end and through which the refrigerant `must pass in flowing through the circuit, the turns in the Other objects of the invention include the prof coil separating under pressure to permit the gas 'to escape therethrough.

The above being among the objects of the present invention the same .consists in certain novel `features of. construction and combinations of parts to be hereinafter described with reference to the accompanying drawings, and then claimed, having the above and other objects in view.

In the accompanying drawings which villus trate -a suitable embodiment of the present invention and in which like numerals refer to like" parts throughout the several different views,

Fig. 1 is a more or less diagrammatic repre--V sentation of a refrigerant circuit embodying a sealed motor compressor unit;'

Fig.` 2 is an enlarged vertical sectional view taken axially .through a sealed motor compressor yunitfor a refrigerating system embodying fear tures of the present invention and taken as, for instance, on the line 2 2 of Fig. 1;

Fig. 3 is a fragmentary, transverse sectional view taken on the line 3-3 of Fig. 2;

Fig. 4 is an enlarged fragmentary, sectional view taken inthe same plane as the view in Fig. 3 and illustrating the mechanism included in the circle 4 of Fig. 3 in greater detail and in further partially broken state; and,

Fig. 5 is an enlarged fragmentary, sectional view taken in the same plane as Fig.- 2 and illustrating those parts within the circle 5 in greater detail.

The present invention has particular relation" to sealed motor compressor units for refrigerating mechanism and is of the general type of construction shown and claimed in` United States Patent` No. 2,035,276, iiled by John R. Replogle and issued March 4, 1936, the same now being owned by the assignee of the present invention. As is well understood by those skilled in the art, in Vthis type of compressor all moving parts of the motor and compressor are contained in a single gas-tight housing eliminating the need of shaft seals or the like to prevent the escape oi' refrigeranttherefrom or the introduction of air thereto. In the Replogle patent above mentioned the motor and compressor have a common shaft Awhich is hollow and through which the refrigerant is fed to the compressor end of the structure and lubricating oil is fed to the same end and Yis distributed therefrom to the various wearing surfaces of the motor and compressor.

. In accordance with the present invention the i'eatureof feeding the refrigerant through the hollow drive shaft is eliminated but the hollow conformation of the shaft is retained and employed solely for lubricating purposes. In this case the shaft is not supported in the same manner as in the Replogle patent and, therefore, requires a variation in the means for feeding the lubricant to the hollow interior of the shaft. Because of the fact that there is no material flow of refrigerant through the shaft as in the Replogle patent and whicl flow of refrigerant in the Replogle patent serves to draw the lubricating oil towards the compressor end ofthe shaft, means must be provided in the present construction for maintaining a body of oil in the hollow shaft and such construction forms one of the features of the present invention. Also in devices of this type it is preferable to allow the power shaft a small latitude of freedom in an axial direction in order to permit the rotor of the motor to seek its natural position axially of the stator, but, at the same time, means must be provided for limiting the axial movement of the shaft so that in handling of the unit in shipping, service, or otherwise displacement of the shaft and the parts carried thereby will not be permitted to an undesirable degree. In accordance with the present invention the means provided for introducing oil into the interior of the hollow drive shaft affords a means whereby the axial movement of the power shaft may be limited to the desired degree.

Another feature of the invention which is applicable to compressors generally but which is particularly adaptable for use in connection with refrigerant compressors whether they be of the sealed type or not, is in connection with muilling means for the discharge side of the compressor. As is appreciated by those skilled in the art the compressed refrigerant discharged by the piston from the cylinder of a compressor into the high side of the system often sets up pulsations of a distinctly audible nature and, because all parts of 'the refrigerating system and particularly the refrigerant circulating passages are constructed entirely of metal, this pulsation noise is telegraphed through the entire system. Moreover on occasions a slug of oil V`willl be discharged from the compressor and will be forced through the refrigerant circulating system, and when such slug is carried through the system as such distinctly audible sounds are created which are considered undesirable. In accordance with the phase of the present invention under discussion means are provided whereby the pulsations of pressure occurring at the outlet side of the compressor are smoothed out so that the refrigerant discharged into the circulation system is substantially devoid of pulsations, thus preventing the audible effects thereof from being telegraphed through the system and from being apparent therein. At the same time it serves to break up any slug of oil that attempts to flow through the system as such and thereby eliminates the undesirable effects thereof.

Referring now to the accompanying drawings and particularly to Fig. 1 there is diagrammatically illustrated a typical refrigerating system in which the numeral l0 indicates generally a motor compressor unit from which refrigerant is discharged through a tube H to a condenser I2 in which the refrigerant is condensed and then delivered to a receiver VI4 from which it is led through a tube I6 to an expansion valve i8 and then to an evaporator 20 in which the expanded gas absorbs heat and then returns through a tube 22 to the motor compressor unit I0 to again be compressed and re-circulated. The present .in-

venton particularly relates to the motor compressor unit l0.

Referring now particularly to Fig. 2 it will be noted that the motor compressor unit I0 comprises a housing 30 the lefthandportion of which is of generally circular section and the open end of which is closed and sealed in gas tight relation by means of a removable cover 32 secured in place by screws 34. The opposite end of the housing may be formed to provide one or more cylinders although in the present case by way of illustration it is shown as formed to provide two cylinder bores 36 therein. The righthand end of the housing is provided with an integral end wall provided with an axial bore 38 which is closed and'sealed by a plug 4U secured in place by screws 42 but which plug is provided with an axial bore M in turn closed by a cap 46 secured in place by screws 46. The housing 38 is also provided with an opening below the cylinder bores 36 which is closed and sealed by means of a cap 50 secured in place by screws 52, this latter opening being for the purpose of facilitating the insertion of the piston assemblies in the cylinders.

Intermediate the opposite ends of the ho sing 30 is a central integral wall 64 provided w n a central bore in which an elongated bearing bushing 56 -is ilxedly received. A shorter bearing bushing 58 is xedly received within the inner end of the bore 44 of the plug 40. Rotatably received by and between the bushings 56 and 58 is a power shaft 68 having a bore 62. The righthand end of the shaft 60 is reduced in diameterV so as to form a shoulder 64 which axially abuts the inner end of the bushing 58 to thus limit movement of the shaft 60 to the right as viewed in Fig. 1. The bore 62 at the extreme righthand end of the shaft 60 is reduced in diameter as indicated at 66 for a purpose which will hereinafter be more apparent.

Upon the shaft 60 and integrally therewith are two eccentrics 68 aligned with respect to thecylinder bores 36. and encircling each of the eccentrics 68 is the big end of a connecting rod 16 the upper end of each of which ls connected by means of a piston pin l2 with a piston 14 received in the corresponding bore 36. Accordingly, it will be appreciated that rotation of the shaft 66 causes reciprocation of the pistons 14, the ecceny trcs being displaced from one another angularly through 180 degrees so as to obtain alternate pumping strokes of the pistons 14.

The lefthand end of the housing 36 interiorly receives the stator of the motor, it preferably being pressed into position in a conventional manner which thereby xes it with respect to the housing 38. The rotor 82 for the motor is pressed upon the corresponding end of the shaft 60 and, of course, is radially aligned with `the stator 80. Openings 84 and 86 are provided in the central wall 54 so as to permit equalization of pressures between the opposite ends of the housing 30 and additionally the lower opening 86 provides for` the return of lubricating oil from the compressor end of the housing to the motor end thereof.

In order to provide lubrication for the various wearing surfaces of the unit lubricating oil is fed into tho bore 62 of the shaft 60 and it is distributed therefrom to the various wearing surfaces. To aid in effecting this result the shaft 82 is provided with al radial hole 88 therethrough in line with the bearing bushing 5S and the shaft 60 is peripherally out away as at 90 on either side of the hole 88 to provide an annular pocket for reception of the oil discharged thereinto from the moana bore 02 oi' the shaft160. Additionally the bore' of the bearing bushing 56 inline withthe hole 58 is internally provided with Vanfannular `groove 82 to further aid in the flow of` oil `through the opening `08. It `willbe appreciated that during rotation of the shaft 60 the oil in the shaft willbe subjected to centrifugal force which will tend to discharge `it radially outwardly through the yhole as well as other oil passages about to be described. In any event it will bey appreciated that the passage just .described affords a means whereby an ample supply of oil may be fed to the wearing surfaces between the shaft 00 and 'bear" ing bushing 60. .v l Another radial oil hole 04 is drllledthrough the shaft centrally of each of the eccentrics 00 and on the radially low side of suc-h'eccentrics.

Each connecting rod is provided with .a centrai. oil passage 08 which -is aligned with the corresponding oil passage 0l once duringi each revolution of the "shaft 60 so that oil discharged through the passagesl 04 not only is fed to wearing surfaces between the connecting rods and their corresponding eccentrics G8, but is also fed through the passages sito the wearing` surface iting axial movement of theA shaft 00 to the left. In order to accomplish this .result a `shoulder is formed onV the tube andwhile in 'the broader as- 1 `fpects of the present invention it makes kno diference whether this shoulder is formed as an integral part of the tube or formed separately `thcrefrom, the. latter is illustrated as the preferable and `more economical manner of accomplishing this result. Accordingly, in order to provide such rshoulder a second tube ||0 is sleeved-upon the tube |08 and the lefthand end thereof is arranged in abutting relationship with respect to the web |05. The opposite end of the tube |1|0 s terminates short of `the corresponding end of the nut member |02, and particularly where a washer as hereinafter described in conjunction there with is not employed, will be of sulcient ydiameter to engage `the nut member |02 to limit movement thereof, and accordingly the shaft 00, to the left as viewed in the drawings. Thus the a righthand end of the tube ||0 andthe lefthand The small bore 66 i their cylinder bores 30 are lubricated by means of oil thrown oil? of the periphery'of the eccentrlcs 60 during operation.

In order `to introduce oil into the interior of the shaft 60 an oil thrower |00 is fixed to the' lefthand end of the shaft 60by means of a hoilow nut member |02 threaded into the corre-f spending end of the bore 02. The radial extremities of the oil thrower |00 extend into yclose proximityto the bottom side of the bore in the housing 30 at the corresponding end of the housing 00 and sulcient lubricating oil is introduced into the `systerrl so as to provide a pool of oil in the lower part oi the housing into which the ends oi the oil thrower dip. The ends of kthe oil thrower thus throw a spray of oil around the interior housing and particularly against the inner circumferential shoulder |04of the cover 32 and the cover 32 is provided on its inner side with a web |05 integral therewith and cooperat-y ing with the inner face of the cover to provide a central pocket |06 into which a portion of this oil drains by gravity. A tube |08 arranged in concentric relation with respect to the shaft 60 has one end fixed in the web |05 in open communicatian with the pocket |00 and the tube |00 extends through the bore of the nutvmember |02 and into the hollow interior or bore 62 of the exaggerated for the purpose of illustrationxonly.`

This tuber|00 forming a means of communication between the pocket |06 andthe bore 02 of the shaft 00 is, in accordance with the present invention, also employed as a means for limend of the bearing bushing 58 will cooperate with the shaft 60 to maintain it agains't material axial movement between them, a certain amount of` such axial movement being permitted so as to permit the rotorv82 to seekits natural centerwithin they stator 80 as is conventionally de- 'Ihe nut member |02 having a bore smaller than the bore 02 of' the shaft 60, its inner end serves in the nature of a dam in the bore 62 serving to maintain a level of oil in the bore 02. A greater level of oil in the bore 02 may tend to produce leakage of the lubricating oil from the bore S2 of the shaft 00 between the bore of the nut |02 and the tube |08 unless otherwise prevented and this particularly where a relatively free fit is provided between these partsl'A Such leakage may be prevented where considered `necessary or desirable by means of a washer VH21," vwhich rotatably but relatively closely surrounds the tube |00 between the corresponding face of the nut member |02 and the righthand end yjef the. tube H0, this washer in effect cooperating 'y between the nut member and the tube ||0 to limit axial movement of the shaft 670 to the left, and suitable axial clearance being left between the washer and the end of the tube ||0 for the purposes previously described. A coil spring H4 surrounds the tube ||0 and is maintained under turn with respect to the nut member |02 during operation of the unit valthough it is `free to turn with respect to the spring H4; K

From the'Y above itwill be understood that in accordance with the construction thus far described means vare provided for introducing 1ubricant into the hollow interior of the shaft 60 and distributing it'therefrom to the various wearing parts of the unit, the means provided for introducing the lubricant to the hollow in'- terior of the shaft also providing a means for limiting the axial movement of the shaft 60 in vone direction and further providing means whereby an unwarranted escape of lubricant from the lefthand endof the shaft is.prevented.`

terlorly'formed to provide a relatively large chamber |26'i`and received within the chamber |26 over each of the bores 36 is a valve plate |28 provided with an inlet port |30 and a discharge port |32. A nat spring type valve |34 is arrangedand is provided with a pocket |42 therein in` open communication with the corresponding inlet port |30. As best illustrated in Fig, 3 one side of the housingr 30 is provided with an inlet conj nectlon `member |42 of conventional construction to which the tube 22 of Fig. 1 or its equivalent is connected and through which refrigerant flows into a bore |44 in the casing 30. A wire screen strainer |46 is provided in the bore |44 as illustrated in Fig. 3 not only to entrap particles of foreign material carried by the refrigerant and preventing them from being carried to the interior of the motor compressor unit, but also to separate out any oil from the refrigerant owing into the compressor. The bore |44 opens into a vertical bore |48 which opens into the crankcase portion of the compressor end of the housing 30 at its lower end and thereby affords a means whereby any lubricant separated out from the gaseous refrigerant in the strainer |46 may flow by gravity into the lower part of the housing 30. The upper end oi' the passage |40 extends into open communicationv with the pocket |40 of both members |38 so that upon each down stroke of each piston I4 the gaseous refrigerant will be drawn through the bore |44 and through the bore |48 to the corresponding pocket |40 and then down through the corresponding suction passage |30 into the corresponding cylinder 36. 'I'he `gas thus drawn into each cylinder 36 during the down stroke of the corresponding piston 14 therein is compressed upon the ensuing up-stroke of the piston and is caused to be discharged through the corresponding discharge port 32 and through the corresponding passage |40 into the chamber |26 of the cylinder head |22. e

with respect to the walls of the bore |52 and the various coils of which are tightly wound together when in normal condition. The lower coils are reduced in diameter as best illustrated in Fig. 4 and the coil at the lower end is closed by brazing or the like as indicated at |58. In order to secure the coil |56 in position and in sealed rela'- tion with respect to the walls of the bore |52,

It will be appreciated that because of the fact that the various turns of the coil |56 are wound tight against each other, that except for the inevitable imperfections in the wire itself and in the winding thereof the coil acts to block the flow Now referring again to Fig. 3 it will be noted that an outlet connection member |50 is provided on thatside of the housing 30 opposite the inlet connection member |42 and this member is in communication with the chamber |26 of the cylinder head |22 through a vertical passage |52 and horizontal passage |54, so that the refrigerant which is compressed and delivered into the chamber |26 may flow out of the compressor through the outlet connection |50 and thence to a condenser such as the condenser |2 illustrated in Fig. 1. It is in connection with the discharge of compressed refrigerant from the compressor that the remaining phase of the present invention is concerned. In other words, means are previded in accordance with the present invention whereby the pulsations which are commonly set up by the discharge of compressed refrigerant from the compressor are smoothed out and thereby muiiled and prevented from being telegraphed as audible sounds throughout the entire system.

This means, as best illustrated in Figs. 3 and 4, comprises a coil |56 of spring wire the major portion of which is arranged in spaced relation of refrigerant therethrough. However, the re' frigerant compressed by the compressor in being delivered under a relatively high pressure to the interior of the coil |56 causes the coil |56 to elongate suiliciently to separate the various, or at least sufcient, turns thereof to such an extent as to permit the escape of the refrigerant between them but, as will be appreciated, the coil delays the flow of refrigerant through it and requires a certain differentialof pressure on opposite sides thereof before it will separate sufficiently to permit a material flow of refrigerant through it. From a practical standpoint it is preferable to so construct the coil |56 that a pressure differential of from one to live pounds will be suiiicient to separate the various coils thereof to an extent sufficient to permit the normal output of the compressor to readily fiow therethrough,v and .although its presence may create a slightly greater head for the compressor to work in the amount is not sufficient to be material. Nevertheless, the resistance which the' oil collecting in the chamber |26 and attempting to flow through the passages |52 as a slug will be intercepted by the coil |56 and will be broken up and mixed with refrigerant in flowing through it, thus effectively eliminating the undesirable features which 'would otherwise be apparent from the presence of such slug.

Formal changes may be made in the specific embodiment of the invention described without departing from the spirit or substance of thev assembly, a pumping element in said chamber operatively connected to said shaft for receiving driving movement therefrom, a motorincluding a stator received within and xed with respect to said housing and a rotor fixed with respect to said shaft, means adjacent one end of said shaft assembly for limiting axial movement thereof in one direction, a pocket formed on the end wall of saidliousing adjacent the opposite end of said shaft, means driven by said shaft for supplying lubricating oil to said pocket, tubular means in open communication with said pocket and projecting into the hollow interior of said shaft, and a shoulder on said tubular means arrangedlin cooperating relation with respect to said opposite'end of said shaft assembly for limitsembly, a pumping element in said chamber operatively connected to said shaft for receiving driving movement therefrom, a motor including a stator received within and fixed with respect to said housing and a rotor fixed with respect to said shaft, means adjacent one end of said shaft assembly for limiting axial movement thereof in one direction, a pocket formed on the end wall of said housing adjacentthe opposite end of said shaft, means driven by said shaft for supplying lubricating oil to said pocket, and means extending between said shaft assembly and said pocket providing for the flow of oil from said pocket to the hollow interior of said shaft assembly and cooperating with said shaftto limit axial movement of said shaft in a direction opposite to the first mentioned direction of axial movement.

3. In a sealed motor compressor unit, in combination, a housing having a. pumping chamber formed integrally therewith at one end thereof. a hollow shaft rotatably 'mounted within said housing, said shaft having a passage therethrough leading to a wearing surface of said assembly, a

pumping element in said chamber operatively ing arranged to receive therein oil acted upon by said oil slinger, a tube in open communication with said pocket extending into the bore of said threaded member, and shoulder means carried by said tube cooperable with said threaded meinsaid shaft, means4 adjacent one end of said shaft for hunting axial movement thereof in one direction, a hollow member threaded into the bore of said shaft at that end thereof opposite to the ber to limit axial movement of said shaft inia first mentioned end and forming an internal dam for retaining a body of oil in said shaft against escape from the corresponding end of said shaft, an oil slinger fixed to said shaft by said threaded member, a pocket in `said housing arranged to receive therein oil acted upon by said oil slinger, a. tube in open communication with said pocket extending into the bore of said threaded member, and shoulder means carried by said tube cooperable with said threaded member to limit axial movement of said shaft in a direction opposite to the direction of the firstmentionedv axial movement.

5. In a sealed motor compressod unit, in combination, a housing having a pumping chamber formed integrally therewith at one end thereof, i

assembly, a pumping element in said chamber operatively connected to said shaft for receiving driving movement therefrom, a motor including a stator received within and fixed with respect to said housing and arotor fixed with respect to said shaft, means adjacent one end of said shaft for Hunting axial movement thereof in one direction, a hollow member threaded into the bore of said shaft at that end thereof opposite to the first mentioned end, `an oil slinger fixed to said shaft by said threaded member, a pocket in said housing arranged to receive therein oil acted upon by said oil slinger, and a tube in open communication with said pocket extending into the bore of said threaded member, said tube having arelatively close running fit in said threaded member whereby to minimize the escape of oil from said shaft at the corresponding end thereof between said tube `and said threaded member.

6. In a motor compressor unit, in combination, a hollow casing providing a cylinder therein, a

, hollow shaft assembly rotatably mounted in said casing, an eccentric on said shaft assembly, a piston in said cylinder operatively connected to said eccentric, a pocket in said casing at one end thereof, means for supplying oil to said pocket during operation of said unit. a tube extending between said pocket and the interior of said shaft assembly whereby to convey oil from said pocket to the interior of said shaft assembly, shoulder means associated with said tube cooperating with an end of said shaft assembly for hunting axial movement of said shaft assembly in one direction, means for limiting axial movement of said shaft assembly in the opposite direction, said shaft assembly having radially directed openings therein for .conveying oil from the interior of said shaft assembly to wearing surfaces of said unit, and sealing means for the jointbetween said shaft assembly and said tube.

'7. In a motor compressor unit','in combination, a hollow casing providing a cylinder therein, a

hollow shaft assembly rotatably mounted in said casing, an eccentric on said shaft assembly, a piston in said cylinder operatively connected to said eccentric, a pocket in said casing at one end thereof, means for supplying oil to said pocket during operation of said unit, a tube extending between said pocket and the interior of said shaft assembly whereby to convey oil from said pocket to the interior of said shaft assembly, shoulder means associated with said tube cooperating with `oil from the interior of said an end of said shaft assembly for limiting axial movement of said shaft assembly in one direction, means for limiting axial movement of said shaft assembly in the opposite direction, said shaft assembly having radially directed openings therein for conveying oil from the interior of said shaft assembly to wearing surfaces of said unit, a washer closely but axially slidably received on said tube, and spring means constantly urging said washer against the corresponding end of said shaft assembly whereby to seal the space between said tube and said shaft assembly against undesirable leakage of oil therebetween.

8. In a motor compressor unit, in combination, a hollow casing providing a cylinder therein, a hollow shaft assembly rotatably mounted in said casing, an eccentric on said shaft assembly, a piston in said cylinder operatively connected to said eccentric, a pocket in said casing at one end f thereof, means for supplying oil to said pocket during operation of said unit, a tube extending lbetween said pocket and the interior of said shaft assembly whereby to convey oil from said pocket to the interior of said shaft assembly, a washer surrounding said tube in abutting relationship with respect to said shaft assembly, a second tube surro'unding the first mentioned tube and terminating short of said washer whereby to cooperate with said washer in limiting axial movement of said shaft assembly in one direction, means cooperating with said shaft assembly to limit axial movement thereof in the opposite direction, and said shaft assembly havingradially directed oil passages therein for conveying shaft assembly to wearing surfaces of said unit.

9. In a refrigerant compressor, a cylinder block having a at head end and a refrigerant discharge passage opening on to said end, a cylinder head overlying said end and having a chamber therein opening onto said passage, that end of said passage opening onto said end being radially enlarged to form a seat, a hollow coil of wirewound with the turns thereof in substantial contact with each other positioned in said passage in generally spaced relation with respect to the walls thereof, one end of said coil being enlarged in diameter and being received in said seat and clamped therein by said cylinder head, and the opposite end of said coil being closed, said coil being formed of spring-like material whereby when the interior thereof is subjected to the discharge pressure of said compressor the turns thereof will separate axially from one another to permit the flow of refrigerant therethrough.

10. In a gas compressor of the type wherein a piston reciprocates in a cylinder and the cylinder is provided with a discharge passage having an associated valve permitting flow of gas from said cylinder therethrough only in a direction from said cylinder, the combination with said passage of means arranged in obstructing relation therein on the downstream side of said passage from said valve, said means being Alocated at a sufficient distance from said valve as to provide a pulsation chamber of material volume in the uid passage between it and said valve, and said means comprising a hollow coil of ilexible wire wound with the coils thereof normally substantially in contact with one another and having one end thereof closed and the opposite end thereof sealed to the walls of said passage,

said means being arranged to receive the iiowy of gas from said compressor in the hollow interior thereof.

1l. In a gas compressor of the t'ype wherein a piston reciprocates in a cylinder and the cylinder is provided with a discharge passage having an associated valve permitting dow nf gas from said cylinder therethrough only in a direction from said cylinder, the combination with said passage of means arranged in obstructing relation there-I in on the downstream side of said passage from said valve, said means being located at a suiiicient distance from said valve as to provide a pulsation chamber of material volume in the fluid passage between it and said valve, and said means comprising a hollow coil of flexible wire arranged with its major portion in spaced relation with respect to the walls of said passage and the various turns thereof normally in substantial contact with one another, one end of said `coil being closed and the opposite end of` said coil being sealed to the walls of said passage, the latter endv of said coil being disposed on the upstream side of the normal flow in said passage with respect to the closedend thereof.

l2. In a gas compressor of the type wherein a piston reciprocates in a cylinder and the cylinder is provided with a discharge passage having an associated valve permitting flow of gas from said cylinder therethrough onlyv in a direction from said cylinder, the combination with said passage of means arranged in obstructing relation therein on the downstream side of said passage from said valve, said means being located at a sufficient distance from said valve as to provide a pulsation chamber of material volume in the fluid passage between it and said valve, and said means comprising a hollow coil of wire arranged with its majo;- portion in spaced relation with 'respect to the walls of said passage and the varito the closed end thereof, said wire being of a spring-like character and at least part of the turns thereof being adapted to separate from each other on the application of pressure internally of said coil whereby to permit the flow of gas therethrough. h

13. In a gas compressor of the type wherein a piston reciprocates in a cylinder and the cylinder is provided with a discharge port having an associated jvalve permitting flow of gas from said cylinder therethrough in one direction only, the combination with said discharge port of a pair of associatedmembers arranged to receive said gas discharged from said port past said valve, one of said members having a passage therein for the iiow of said refrigerant and said passage being enlarged to provide a seat adjacent the line of junction of said members, a hollow coil of Wire having the turns thereof in sub` stantial contact with each other received within said passage, said coil being provided with a radial enlargement adjacent one end thereof received in said seat and clamped thereagainst by the other of said members when said members are secured together, the opposite end of said coil being closed, and said Wire being of resilient characteristics whereby pressure on the interior of said coil materially in excess of that on the exterior thereof will effect elongation of said coil and separation of at least certain turns thereof to permit the ow of refrigerant therethrough.

14. In a gas compressor of the type wherein,

a piston reciprocates in a cylinder and the cylinder is provided with a discharge port having an gas discharged from said port past said valve, one l0' of said members being provided with a passage therein and the other oi said members overlying a face of the tlrst mentioned member and arranged to deliver refrigerant to said passage, said passage being outwardly iiared at that end 15 thereof closest to the second mentioned member,y and a hollow coil of resilient wire disposed in said passage in generally spaced relation with respect to the walls thereof, said coil being wound with the various turns thereof in substantial contact with veach other and the turns at one end thereof being enlarged to form a tapered end portion complementary in shape and size to said flaredl endA of said passage and received therein, said tapered end being clamped against the walls of said ilaredy end of said passage when said second mentioned member is secured to: said rst mentioned member, and the opposite end of said coil being closed.

OSKAR H. BUSCHMANN.