US1916130A - Compressor - Google Patents

Description

L. L. TORREY June 27, 1933.

COMPRES SOR Filed Dec. 29, 1928 -5 Sheets-Sheet 1 June 27, 1933. L. TORREY 1,916,130

\ COMPRESSOR Filed Dec. 29, 1928 3 Sheets-Sheet 2 June 27, 1933. 1.. L. TORREY COMPRESSOR Filed Dec. 29, 1928 5 Sheets-Shed 3 Patented June; 27, 1933 UNITED STATESI LUCIEN' L. TORREY, OF LOS ANGELES, CALIFORNIA comrzanssoa Application filed December 29, 1928. Serial No. 829,105.

This invention relates to improvements in compressors, and more particularly concerns a compressor which is excellently adapted for employment in a refrigerating system.

()ne of the objects of the invention is to provide a compressor in which a type of valve is employed that is substantially noiseless in operation and permits the operation of the compressor with a minimum clearance and so that the valves open and close automatically and at. times when the pressure differences thereon are substantially balanced.

Another object of the invention is to provide means whereby the lubricating oil and the moving parts in the crank case, and especially the inner ends of bearings for the main shaft, shall be kept. during operation at a pressure slightly less than atmospheric, so

that the crank case gases shall not escape into easily placed and removed, and which is of simple and cheap constructionof itself.

A further object is to provide a compressor having an automatically sealed trap in the outlet or high pressure conduit;so that lubricating oil entering this conduit is separated and immediately returned to the oil supply sump.

Another object of the invention is the provision of a'compres'sor especially adapted for a refrigerating system, in which all possible means are provided to prevent intermingling of lubrlcat ng 011 and refrigerant, to which endpnly minor contacts are permitted between "the oil and the refrigerant, and then only when the latter is in the gaseous stage; and further means are provided for removing the refrigerant from the oil, and the oil from the refrigerant. i

With these and other objects in View as will appear in the course of the following specification and claims, illustrative forms of the in- .vention have been represented on the accomsomewhat larger scale, showing the compressor arrangements.

Fig. 2 is a horizontal sectional view on an enlarged scale substantially on line 22 of Fig. 1a.

Fig. 3 is a plan view of a replaceable valv plate, substantially on line 33 of Fig. 1a.

Fig. 4 is a vertical sectional view, substantially on line 4-4 of Fi 2.

Fig. 5 shows, a mod i cation of the float valve housing.

The compressor according to the'present invention comprises a crank case having an oil supply sump, and a cylinder witha piston operating therein for compressin the returning. gaseous refri erant and elivering it"for condensation. 611 top of the is mounted a valve plate containing automatically operating reed valves designed for providing a very small clearance within the cylinder, so that the compression of the gas,

ortion by portion, may be obtained without cylinder t e necessity of raising large volumes to the requisite pressure, and then permitting the reduction of suchpressure-on the portion of the gas which has not passed through the outlet valve. Mounted over this valve plate 1 is the cylinder head proper, which is provided with enlarged chambers for equilibrating the pressures at the low and'high portion sides. The compressor employs thelow pressure chamber, which during the operation of the compressor may be brought to a pressure below atmospheric, as a means of maintaining the crank case and associated parts at a pressure less than atmospheric,

whereby the lubricating oil may be freed from refrigerant. The high pressure chamber is employed as an oil tra to separate any oil, and permit it to return y gravity to the crank case, past a pressure sealing float. The cylinder head is providedwith shut-ofi' valves for permitting the repair of the compressor without entire drainage of the system.

In the drawings, in Fig. 1, the compressor 4 is shown as applied in a refri erating system, in which the compressor has a driving pulley P operated from an electric motor M by a belt B. The compressor receives the returning gaseous refrigerant under low pressure from a pipe and delivers it under increased pressure through a pipe 11 passing shut-oii valve 12 into the condenser coil K where it is cooled and brought to liquid condition so that it flows through the outlet conduit 13 past a shut-off valve 14 into a liquid the liquid refrigerant is evaporated as usual and returns through the pipe 10. The conduits and structures between the compressor including the outlet of the compressor, the

pipe 11, the condensing coil K, the deliveryconduit 13, the liquid refrigerant tank T, and. the liquid refrigerant conduit L, constitute a high pressure portion of the system, while the evaporator chamber G, evaporator coils H, and gas returnconduit 10 and the inlet side of the com ressor, constitute a low pressure portion 0 the system. The condenser coil K is referably surrounded by a jacket J and a an R is directly driven from the motor M and serves to force air over the condensing coil K whereby to absorb the heat of compression of the high pressure gaseous refrigerant, and cause it to condense to for the liquid refrigerant.

"As shown in ,Fig. 1a, the com ressqr C comprises a bottom plate 20, a b y casting havm the crank case portion 21 and the cylin er portion 22, a unitary valve platestructure 23, and a cylinder head 24. The

bottom plate 20 and the crank case 21 are held together in sealed relationship by the bolts 25, and provides a crank case sump for a supply of lubricating oil 26. The main shaft 27 of the compressor is provided with one or more offset cranks 28 to operate the connecting rods 29 connected to the pins 30 of the respective istons 31. It will be understood that any esired niimberofcylinders may be provided, and that the following description applies to each such cylinder. The piston is provided at its top with the bearing and compression ring 32, and at the bottom with the beari and oil scraper ring 33, while between t ese rings the body of the piston iscut away to form a chamber to reeeive and catch lubricating oil, which is permitted to return by suitable apertures 34 to the interior of the piston, and thence to the oil supply sump 26. The main bearings 35 for the main shaft 27; are provided with wick oilers 36 to suck up lubricating oil by capillary attraction from the sump 26 and maintain these hearings under ptroper lubrication. The bearin on the sha crank 28 is likewise lubricated y a wick 37 which dips into the oil supply sump 26 during the rotation of the main shaft 27. I

The unitary valve plate 2 3 is provided with twocavities 40, 41 on opposite sides of the plate, and each being of substantially keyhole shape, and provided at the enlarged end ness, which is tempered and ground down to v about one-half of such thickness, whereby to form a light resilient valve having definite plane surfaces to cooperate with the valve seats 44. The discharge valve 48 has fixed thereto a plug member 50 which serves substantially to fill the respective passage 43 through the valve plate, for establfshin minimum clearance and uniform operation o the valve, as will be pointed out hereinafter.

Thecylinder head 24 is provided with the inlet chamber 51 and the outlet chamber 52 of substantial size, which serve to com nsate diiierences inpressure arising from riction in the pipes 10 and 11 and the parts connectedthereto, so that the relative back and head pressures upon the compressor are kept at'a low level. The cylinder head 24 is pref-- erably formed of a body casting having the alined inlet passage 53 and outlet assage 54, which are respectively closed at t eir outer ends by the plugs 55. Threaded sleeves 56, 57, 58 and 59 are screwed into cross assages opening into the passages 53 and 54 Fig. 2), and of these the sleeves 56 and 58 are respectively provided with means for connecting and sealing the gas return pipe 10 and the compressed gas outlet pipe 11 ,for'communication with the respective inlet and outlet passages 53 and 54. The inner ends of the bushings 56 and 58 are formed as valveseats 60, 61. The bushings 57 and 59 are provided with threaded valve stems 62, 63 passing therethrough, and adapted upon rotation to present their respective heads 64, 65 into sealmg relationshipwith the valve seats 60, 61.

Suitable packing means are provided for these valves, including the stem packings 66 and the oove 45 provides a freepassage for haust chambers 51, 52 have fiat bottoms except I vtures 68, 69 to receive the clamping bolts 70a which pass down into the cylinder block' 22, and serve to clamp the members together. Thin paper or lead gaskets may be employed to establish the seals between the several members. It will be noted that the intake and exfor' the openings 70, 71 through which the gas passes into and out of the compressor cylinder, so that a very firm seat is provided for the gasket betweenthe cylinder head and valve plate: and correspondingly a large area is provided between the valve plate and the end of the cylinder block, even though the parts are made of small dimensions and close together and exposed to of several atmospheres.

The floor of the inlet passage 53 in the cylinder head 24 is provided with a small aperture 80 communicating with an aperture 81 in the valve plate 23, and thence with a pressure differences cavity 82 in the cylinder block 22, which is continued as a bore hole 83 of lesser diameter,

- which opens into the crank case chamber21 of crank case 21.

the compressor. A valve seat 84 is secured in the cavity 82 to cooperate with the valve member 85 having its stem guided in a spider plate 86 held in the cavity 82. This valve is a pressure relieving and suction valve for withdrawing gaseous refrigerant from the The floor of the outlet or exhaust conduit 54 is provided with a hole 87 communicating with a similar hole 88 in the valve plate 23, and thence by a small orifice 89 through a closing plug 90 with an oil collection chamber 91 having a float 92 therein to be supported by the oil collecting in this chamber. This float has a guide stem 93 movable in a passage 94 in the closing plug 90, and is provided on its lower end with a needle valve 95 to-be seated in the walls of a passage 96 of a bottomclosing plug 97 when the float is in lowered position.

It will be noted that the head of piston 31 closely conforms to the bottom surface of the valve plate 23, andthat a clearance of .002 or .003 of an inch may easily be provided in construction, without disadvantage or danger of breakage by reason of the circulation of oil or liquid refrigerant through the cylinder drops until it is substantially equal to or a little less than the pressure in the intake -chamber 51. The reed valve 47 is then opened, at thisbala'nce of pressure, and gas flows downward through the aperture 42, the groove 45 and into the cylinder.-

The relatively large volume of-the chamber 51 prevents wire drawing and assures that the cylinder shall have a substantial volume of gas refrigerant to operate upon. I

During the up-stroke of the piston, the pressure in the cylinder rises until 'it is substantiall equal to the low pressure in the intake ciamber 51, whereupon the valve 47, closes by its resiliency, at thebalance of pressures. Thereafter, the compression in the cylinder rises further in the usual manner, until a balance of pressure is established between that in the cylinder and that in the exhaust chamber 52, and then the exhaust valve 48 is opened, and the gas under high pressure is passed through the aperture 43 and the groove 45 into the chamber 52 whence it flows by the passage '54 to the high pressure gas line 11 and to the condenser in the usual manner, being cooled in the latter anddelivered as liquid by pipe 13 into the liquid storage tank T, and then forced under the high pres sure of thesystem by the high pressure liquid line L through the controlling and ekpansion valve'16 until the tank G is filled to the level determined by the float F. The coils H are constantly filled with liquid refrigerant, and by absorption of heat from the chamber which is being cooled, this liquid refrigerant is gasified and returned by the low pressure gas line 10 to the compressor for a further passage through the cycle.

It will be specifically noted that the head of piston 31 may be brought very close to the bottom surface of the valve plate 23 during compression, and that thevery small clearance space is left in the cylinder, and especially that the valve .47 is located but slightly above the'lower surface of this plate, while the valve 48 carries the filler member 50 to substantially fill the aperture 43. The flange 44 in each instance is made of substantial internal diameter so that a large aiea of flow for the gas is provided for a small movement of the respective valve 47 or 48. a

Only the thin film of oil remaining on the cylinder walls during the downward stroke of the piston is exposed to the gaseous refrigerant in the compressor, and if any of this oil is carried along during the compression,-it immediately collects on the wall of theexhaust chamber 52, and flows downward through the openings 87, 88 and collects in a pool in the chamber 91 until a sufficiency of this has accumulated to raise the float 92, and How downward by gravity and under the diiferem tial of pressure between the high pressure portion of the system and the crank case, into the oil supply sump 26. It will be noted that the oil thus passing is exposed to the same high pressure as the refrigerant gas, and that it is warmed by the compression, so that it contains substantially no refrigerant absorbed or dissolved therein.

However, if any refrigerant is contained in the oil in the crank case sump 26, this, by its vapor tension, produces an "atmosphere so to speak of the refrigerant gas in the upper art of the crank case and beneath the piston.

uch gas passes by the conduit 83 to the lower 1 side of the valve85, and during the suction of the compressor, the valve 85 will be raised whereby to draw ofi this gas from the crank case. ,It will be understood that normally the low pressure gas line 10- is operated by -less than atmospheric pressure, in order to secure a proper efiiciencyin the evaporator G, H: and hence the. pressure in the crank case 21 may be maintained at less than atmospheric,'so that no gage pressure-exists in the crank case during the actual operation of the compressor to force refrigerant vapors out of the main bearings, etc thus further safeguarding these hearings against the passage of obnoxious refrigerant into the atmosphere of the room, in addition to siphon or like bearing-seals.

Further, since the compressor is hotter while running than it is after a period of quiescence, owing to the heat of compression of the gas being delivered to the c linder walls, and to these walls cooling 0 upon stoppage of the compressor, it-is apparent. that the crank case 21 will likewise have its contents cooled during a standstill, so that at such times there is even less tendency for refrigerant to escape from the compressor.

In the event of any disturbances in the system, the several parts may be shut off and disconnected. For example, if the valves or other parts of the compressor should be giving trouble, the valve caps 67 are removed, and valve stem 62 turned until the valve head.

64 engages-seat 60,- and then the compressor is operated a moment or two to clear the chamber 51.and passage 53: and then the valve stem 63 is, moved to close valve head 65 ilpon its seat 61. The conduitslO and. 11 are" then each shutofi' from the atmosphere. The bolts 7 0 may now be removed,- and the valve plate 23 slid ,out from heneaththe cylinder head .24 and replaced by a new one if necossary. It will be noted that no parts interfere" with the free sliding of the valve plate 23: and that there is at most only, a slight springing of the cylinder head 24 withvthe pipes 10 and 11- during the relnoval of thisplate and the insertion of anew one with-the appropriate gaskets. It will further be noted that bya proper running of the compressor, and the'employment of ,the further valves 12, 14 and 15, any part'of the system v may be charged with the refrigerant, while a remaining portion is substantiall exhaust. ed thereof: so that the parts of t e system may be individually disconnected and repaired. j

It is not necessary to form the passage 83 and chamber 91 integrally in the cylinder block 22: but these members may be located in separate structures as shown in Fig. 5 of the drawings, in which a top connection from the crank case 21a supports a vertical chamber 91a containing the float valve 92a, and communicating at its upper end bya nipple 89a with the outlet chamber.52a: while the inlet chamber 51a communicates with a valve chamber 82a having a valve therein to close the chamber 82a with respect to the communicating pipe 83a leading downward and opening into the crankcase 2111.

It is obvious that the invention is not limited to the forms of execution shown, but 7 blocks, and'valve members mounted in the walls ofsaid cylinder head block and movable across respective portions of the intake and exhaust chambers to establish respective sealing relationship with said valve seats whereby to block communication between said inlet and outlet conduits independently of said valve.

2. In a compressor, a crank case constituting a sump, a cylinder and a piston therein, a cylinder head having inlet and outlet chambers, and valves located between said chambers and said cylinder, the outlet chamber comprising an oil separating trap, and a gravity discharge conduit for separating oil from said "outlet chamber and including a collecting chamber, a float insaid collecting chamber, and a valve controlled by said float and opened when the said float rises upon the collection of oil in said collecting chamber whereby the oil may be returned to said sump.

3. In a compressor,a cylinder block, acylinder head block, a flat valve block interposed between said cylinder and cylinder head blocks and means to clamp said blocks together in sealing relationship, said valve blocks having apertures therethrough to provide communication between said cylinder head block and the cylinder, a reed valve to each of said apertur s, said reed valves being mounted on'opposit sides of said valve block, and a fillingplug carried by one of said reed valves to substantially fill the respective aperture whereby to reduce the clearance volume in the cylinder. 7

4. In a compressor, a cylinder block, a cylinder head block, a cylinder valve block interposed between said cylinder andsaid cylinder head block, and means -to clamp said blocks together, said cylinfiir head block having inlet and outlet cliam er's therein, said chambers therein, a fiat valve block of uniform thickness interposed between said cyle inder and said cylinder head blocks, and means to clamp said blocks together in sealing relationship, said valve block comprising a'valve' plate having apertures there 2 through to establish communication between said chambers and said cylinder, said plate being cut away around eachapertureand on opposite sides of said plate to providea valve seat cavity having a lateral extension therefrom, reed valves fitted in said cavities to respectively close thesame, and means to hold said valves on said valve plate, said means being located in said extensions.

6. In a compressor for refrigerating purposes, a-cylinder havinga cylinder head, a piston in said cylinder and a crank shaft to move said piston, a crank case providing means to support said crank shaft and having a closed chamber constituting a sump for lubricating oil, said cylinder head including inlet and outlet chambers, said .crank case and cylinder being in communication 'so that the refrigerant may enter' said crank case chamber, and valves to control the admission of gas from said inlet chamber to said cylinder and the discharge of compressed gas from said cylinder to said outlet'chamber, said cylinder and cylinder head having a passage extending from the crank case to the inlet chamber, said conduit being enlarged near its upper end and provided with a valve seat, and a gravitationally closed valve in said enlargement, said valve being raised from its seat by and during the suction stroke of the piston whereby gas may be sucked from said crank case chamber into said inlet chamber.

7. In a compressor, a cylinder block, a cylinder head block, a crank case, a valve block interposed between said head and cylinder blocks, means for providingca conduit from the crank case to the valve block, a valve for closing said gas conduitwhen the pressure in said inlet chamber has greater than a'predetermined ratio to the pressure in the crank case, said head block having inlet and outlet chambers and inlet and outlet connections to said chambers, said valve block having cylinder inlet and outlet ports for establishing communication between said conduit and said chambers and a port for establishing communication between said conduit and the inlet chamber, inlet and outlet valves mounted upon said valve block 'for controlling the said inlet an outlet ports, and clamping means for holding said blocks together whereby the valve block establishes. sealed communications between said cham-- bers and "the cylinder and conduit.

' 8. In a compressor, a cylinder block having a flat end, a cylinder head block having a fiat face opposite said flat end and inlet and outlet chambers, a fiat valve block interposed between said flat end and fiat face and having inlet and outlet ports for establishing communication between the cylinder and said inlet-and outlet chambers, valves for closing said ports located wholly between the s faces of the valve block, inlet and outlet connections to said inlet and outlet chambers, and releasable clamping means for holding said blocks together whereby the'valve block may be slid out upon releasing said clamping means and without disconnecting said connections.

9. In a compressor for refrigerating'pifrposes, a cylinder and a piston thereinfa cylinder head having inlet and outlet chambers,

a crank case providing a sump for lubricant, a gas conduit from sa1d crank case to' sa1d inlet chamber, a valve for controlling said conduit and opened byand during the suction stroke of the piston whereby the crank case is maintained under evacuation during operation, a gravity drainage con'duit from said outlet chamber to said crank case, and a float-controlled valve for normally closing said conduit and preventing passage of gas from said outlet chamber to said crank case,

said gas conduit operating to-draw ofl'. gas,

trapped in the oil and to maintain the crank case at low pressure during operation where-- stroke of the piston whereby the crank case is maintained under evacuation during operation, a fiat valve block interposed between said cylinder and cylinderhead and having 'nlet and outlet ports for establishing communication between the cylinderand said inlet and outlet chambers and a gravity dis charge port from said outlet chamber, inlet and outlet valves mounted on and located wholly between opposite faces of said valve conduit closed, and re valve and a contro valve block together, whereby said block may he slid from between said cylinder and head without interference with or by said float and valve.

In testimony whereof I aflix my signature.

LUCIEN L. TORREY.

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