US2627170A - Hermetic refrigeration compressor - Google Patents

Description

Feb. 3, 1953 J. TOUBORG HEIRMETIC REFRIGERATION COMPRESSOR Filed Sept. 27, 1948 4 Sheets-Sheet 1 Fig.2. 1 i ii F 4}? 5. v: r T i l u i l f attorney Feb. 3, 1953 J. TOUBORG 2,627,170

HERMETIC REFRIGERATION COMPRESSOR Filed Sept. 27, 1948 4 Sheets-Sheet 2 4 51 V 6 L u r 11" 67' Imnentor 71 7 Jensfozzozg,

24 7113 89 as WQW Clttrneg Feb. 3, 1953 OUBORG 2,627,170

HERMETIC REFRIGERATION COMPRESSOR Filed Sept. 27, 1948 4 SheetsSheet 5 Jens T0 Feb. 3, 1953 J. TOUBORG 2,627,170

HERMETIC REFRIGERATION COMPRESSOR Filed Sept. 27, 1948 4 sheets sheet 4 11 111 91,1 1 I 28 a, 11 l 94.

325 g 101 03 1 F 9 8 2113: 1 85 F1981] 7 z 1 87 1 Q 121 131' M1 10 111 91% 127 A 1 1 I12 T V I 12 Pip-9 Zmnemor Jens fouwrg,

CI orneg Patented Feb. 3, 1953 HERMETIC REFRIGERATION COMPRESSOR Jens Touborg, Tecumseh, Mich., assignor to Tresco, Inc., Tecumseh, Mich., a corporation of Michigan Application September 2'7, 1948, Serial No. 51,348

Claims. 1

This invention relates to a hermetic or sealed compressor, and it has particular reference to an improved compressor applicable to refrigeration systems. The compressor herein disclosed has subject matter in common with that described in my copending application Serial No. 774,323, filed September 16, 1947, and now Patent No. 2,540,062, January 30, 1951, and accordingly this application may be deemed to be a continuation inpart.

One purpose of the invention is to provide a hermetic compressor, incorporating a fractional horsepower motor, which is extremely compact and of relatively small dimensions for its compressive capacity. When assembled in or with refrigeration cabinets, a greater percentage of the cabinet volume may therefore be given over to the cooling compartment.

Another object of the invention is to provide an improved internal resilient mounting for the compressor cylinder and motor, wherein transversely disposed springs are employed to mount the movable parts in predetermined and spaced relation to the casing walls. Other objects of the invention are to provide an improved lubricant circulating pump; to provide built-in mufller chambers further to minimize the development of noise; to provide for the recirculation of compressed and cooled refrigerant through the lubricant, thereby to absorb heat from the compressor and increase its operating efficiency; and generally to provide improvements conducive to economics in manufacture and durability and high efllciency in operation.

The invention will be readily understood from the following description of a typical embodiment, illustrated in the accompanying drawings, wherein:

Fig. l is a side elevation of the compressor as assembled with a flue-type or static condenser on a domestic refrigerator cabinet.

Fig. 2 is a rear elevation of the compressor and condenser assembly shown in Fig. 1.

Fig. 3 is a vertical section through the compressor, with certain parts shown in elevation.

Fig. 4 is a bottom plan, the compressor casing being shown in section.

Fig. 5 is an enlarged view, partly in section and partly in elevation, as viewed from the left of Fig. 3.

Fig. 6 is a section on the line 6-6 of Fig. 5.

Figs. 7 and 7A are companion views, on an enlarged scale, illustrating the relations between piston, crank, and lubricant pump during the compression stroke of the piston. They are taken on irregular se t on ines through the same Parts shown in Fig. 3, looking up from the bottom.

Figs. 8 and 8A are also companion views, taken the same as Figs. 7 and 7A, showing the relations between the same parts during the suction stroke of the piston; and

Fig. 9 is a perspective of the crankshaft crosshead. 1

' In Figs. 1 and 2, there is illustrated a hermetic compressor generally designated by the reference numeral 20, as it may appear when assembled in a complete refrigeration system for a domestic food storage cabinet. The working partsof the compressor, hereinafter described, are enclosed in a sealed casing 2| having generally the form of a relatively short cylinder. A mounting bracket 22, welded or otherwise secured to the periphery of the casing, serves to suspend the compressor from a rail or bracket 23 mounted transversely on the rear wall of a domestic refrigerator cabinet 24, and in such manner that the axis of the casing is disposed horizontally. The rail 23 also forms a part of a vertically positioned, flue type, condenser 25, extending over the rear wall of the cabinet, and above the compressor 20. The refrigerator cabinet is invariably set up against a wall 26 of the kitchen or other room when placed in service, and the space between the walls thereby forms a flue or stack, through which air will flow by induced draft to remove the heat of compression. from the refrigerant flowing in the system. This is one way in which the parts may be assembled, but it should be understood that other assembly plans may be utilized insofar as the compressor itself is concerned.

The condenser 25 is formed from a length of tubing 21, bent back and forth a few times in serpentine fashion, and a second longer length of tubing 28,"also bent back and forth. The straight portions or runs of the tubes are equipped with longitudinally extending fins 29, herein shown as channels having their webs soldered or otherwise connected to opposite sides of the tubes. and their flanges 3| extending inwardly toward each other. Brackets, such as the bracket 23 and comparable brackets 32, are secured to the tube runs at the ends of the fins 29, and adjacent the return bends 33, to integrate the structure and give it desirable rigidity. It will be seen that the facing channel shaped fins provide independent air flues, apart from the stack made by bringing the cabinet 24 close to the wall 26. ,A further description of the condenser itself will be; found in my copending' application, Serial No: 51,347, filed September 27, 1948, now abandoned.

The purpose inproviding two lengths of tubing 2i and 28, instead of one continuous length, is to eifect recirculation of cooled refrigerant into the compressor crankcase and oil bath. The inlet end of the tube 21 is connected to a discharge line 36 directly connected to the compressor exhaust, While the other end of the tube 2'! is connected to a duct 35 which also enters the casing 2i, and is there connected to a cooling coil submerged in the oil bath, as will hereinafter be explained in detail. The compressed refrigerant then fiOWs again out of the casing 2| through a line 36- which is connected to the inlet end of the tube 28, through which it flows, with concomitant cooling by the induced air draft, to the condenser outlet 31, located at the opposite end of the tube 28. The refrigerant then flows through a strainer 38 and supply line 39 to an evaporator ell located in the cabinet 24, and is returned to the compressor 26 through a suction line :12 which discharges into the casing 2 I. Inasmuch as the control of the cycle of operation is conventional, it is deemed unnecessary to illustrate the elements employed for this purpose, or to describe in detail the electrical overload and starting relays, contained in a box '43 secured'to the exterior of the casing 2!, from which extends an electrical service cord at for connection to a source of current.

The construction of the compressor 29 is more fully illustrated in the remaining views. As shown in Figs. 3, 4, and 5, the. casing 2| is formed of two sheet metal shells i and 52, one of which is somewhat deeper than the other, and each of which is formed with an annular flange 53 to provide abutting rims which can be weldedto each other to seal the casing. Within the casing is a hermetic compressor unit, comprising an electric motor 55, a casting55, and a refrigerant pump 55, all of which are connected together and are resiliently mounted in spaced relationto the casing walls. The casting 55 is generally cannular in form, and it is provided at diametrically opposed points with outstanding lugs 57, each of which is transversely bored to accommodate mounting means, as Will presently be. described. The casting is centrally formed withqan upstanding bearing boss 58 which is axially bored to receive a vertically disposed main shaftiil, whose ends project both above and below the/boss 58.

The upper end of the shaft 59 receivesabored and counterbored quill 6| whose internal shoulderseats on-the upper end of the boss '58 to provide a thrust and supporting bearing. The quill may be afiixed to the shaft by a press fit, set screw, or like means, and its external surface is pressedinto a rotor 62 for the motor 54. The motor stator 63 is seated inan annular shoulder 6.4, formed in the upper .rim .ofthe casting 5.5, and it is retained ingpositionby bolts 65 (Fig. 4), extending upwardly through suitably located apertures. The motor lead wires 66 extend through an aperture 6'! in the body of the casting to insulated terminals ,63 which pass through the wall of the she1l'5l forconnection to the relays contained in the box .43.

The casting 55 and the parts connected thereto are internallymounted in the casing 2| by a resilient suspensionv cooperating with the casting lugs 51. The casing sections'Bl and 52 are each provided with spaced pad portions H and 12, re spectively, located substantially radially equidistant'from the longitudinal axis of the'cylindri'cal dimension of the casing, and in an axial plane parallel thereto. Opposed pads may therefore be brought into axial alignment when'the casing shells are superimposed. As best shown in Figs. 4 and 5, each pad is provided, on its inner surface, with abutments or sockets 13 which may conveniently be welded thereto. The ends of transversely disposed spring supporting and retainer rods 14 extend into and are supported by the aligned sockets, and these rods pass through coarsely tapped openings 15 in the lugs 57. Each rod is surrounded by a coiled spring 16, and these springs also pass through the opening 15, and abut the ends of the sockets 13.

Inasmuch as the springs 16 are helical, and are herein shown also as being cylindrical, they may be screwed into the apertures 75 to project on each side thereof the correct distance, in order to center or locate the compressor assembly with respect to the casing walls. While the springs are thus in contact with the lugs, they do not touch the rods 7 3, except at the end turns, which are bent on a progressively decreasing radius, as will be apparent from Fig. 6. The end turns are also bent to approximately circular, rather than helical form, to engage as much as possible the end surfaces of the abutments 13. Each end of the rods 14 is formed with a small key H, which can enter any one of a number of keyways it formed in the sockets 13, thereby retaining the rod from rotation. These keys also provide rotational stops for the ends of the springs, which abut the keys on one side thereof, while the end turns closely engage the periphery of the rod, passing tangentially to the opposite sides of the keys as they merge into the spiral convolutions of greater diameter. Both rods and springs are therefore restrained from rotation after assembly, and the springs may be accurately adjusted between the ends of the sockets.

The spring mounting and suspension just described Will fully andadequately support the casting assembly in the casing in the desired spaced relation to the walls thereof. Rotative forces tending to turn the entire assembly around the axis of the shaft 59 are absorbed by the springs acting under compression, or axially, while forces acting in'a vertical direction are counteracted by the rigidity of the springs 15 considered as beams. Among such vertical forces is the Weight of the casting assembly, which tends to bend the springs 16 so that they contact the rods '54 at the lugs 57. In some instances, the total weight of the casting assembly is such that, in order to give the springs it enough resistance against fiexure to prevent their bottoming on the rods i l, it is necessary to sacrifice some of the desired softness along the axial direction. The result of such sacrifice is an inability of the springs it, when acting in compression, to absorb or damp out a much of the vibratory forces imposed thereon as is desired, resulting in the transmission of a greater amount of the vibrations to the casin walls, and with it some noise.

In order to counteract this possibility, and to maintain the noise of operation at the lowest possible level, and at the same time retain the over-all casing dimensions to a minimum, a portion of the total weight of the casting assembly is borne by coiled tension springs '53, whose ends are hooked respectively in pierced brackets 8i, connected to and depending from the inner peripheral wall of the shell 5i, and ears 32 on the upper portions of thelugs 5?. The springs 1'9 may be made :to support such portion of the total weight as is desired, andproportionately the springs it may bemade softer, and thus more eifectively absorb the forces which would otherwise be transmitted to the casing. The matter thus becomes one simply of selecting two sets of springs having rates compatible with the total weight of the casting assembly, the horsepower of the motor, and the duty expected from the compressor, so that vibration and noise may be reduced to a minimum. In so selecting the springs, it is apparent that, by giving to them different natural rates or vibration frequencies, they may act together to suppress any adventitious vibratory influence which might be in harmony with one or the other. Forced or sustained vibrations are thereby damped by lack of resonance.

In the course of assembly, the motor 54, casting 55, and refrigerant pump 56 are initially assembled as a unit, and the rods I4 and springs I6 are also assembled with each other and through the lugs 51. The casing shell 5I is then laid on its side, as shown in Fig. 4, and the ends of the rods 14 are placed in the sockets I3 and are locked from rotation therein by the keys 11, which enter whatever keyway adjustment purposes may dictate. The springs 19 are then connected, and, after effecting such other connections as are indicated, that is, the wires 66, etc., the shell section 52 is positioned, with the upper ends of the rods entering the companion sockets 13 in such shell. When the flanges 53 abut, the springs 16 will be placed under some compression, tending to expand their convolutions, and securely and resiliently mounting the working parts within the casing.

The refrigerant pump unit 56 comprises a cyl inder block 85, having a cylinder 86 bored therein, whose head end is covered by a valve plate 81 and a cylinder head 88 bolted thereto. The cylinder block assembly is secured to the under side of the casting 55 by bolts 89. A piston 9| is reciprocably mounted in the cylinder 86 by means of an offset or crank portion 92 formed on the lower end of the shaft 59, and below a crank arm 93 which carries a counterweight 94. The crank 92 rotatably fits into a vertical bore 95 of a crcsshead 96 (see also Figs. 7 to 9), which is carried for transverse reciprocatory movement in a yoke 91, integrally connected to the crank end of the piston 9I. The driving connection will thus be recognized as being of the Scotch yoke type.

Refrigerant vapors returning to the compressor 29 through the suction line 42 enter the casing 2| at the upper part, circulate around the motor 54 to absorb some of its heat, and then pass into a suction tube I9I extending from one side of the head end of the cylinder block 85 to the upper portion of the casing. It will be noted that the upper end of'the'tube [9| is creased axially along a diameter, so that the opposite walls contact, and thus. in eifectform a double-barreled section I92, through which the returning refrigerant is inducted. It has been discovered that by dividing the total crosssectional area of the tube I9I into a number of smaller areas, a slight hissing noise, caused by pulsation of the inducted refrigerant vapors, is thereby eliminated. I

As best shown in Figs. 7 and 8, the cylinder block 85 is formed with laterally extending portions I03 and I94, each of which is internally cored to provide mufller chambers I95 and I96 respectively forboth incoming and discharging refrigerant. The lower end of the suction tube I9! is positioned in a duct III'I communicating with the chamber I95, and a second duct I98 leads from the chamber to a cavity I99 in. the cylinder head 88, which in turn encompasses inlet ports H9 in the valve plate 81, covered by a suction valve III. Refrigerant is accordingly inducted into the cylinder 86 on the suction stroke of the piston 9| as indicated by the arrows in Fig. 8. On the compression stroke, illustrated in Fig. 7, the refrigerant is forced through ports H2 and past a discharge valve H3 into a spaced cavity H4 in the head 88, and thence through a duct H5 communicating with the discharge muffler chamber I96. The refrigerant then flows through a duct H6 into a discharge tube II'I, coiled in a bath of oil contained in the casing 2I, and which terminates in the discharge line 34 leading to the condenser, as previously ex plained.

The provision of built-in muffler chambers in the block 85, for both the inlet and discharge sides of the cylinder, greatly reduces the tendency to develop noise, and also simplifies the construction and assembly. As the discharge tube HI tends to vibrate from the pulsating fiow of compressed refrigerant, its formation into a coil, and

disposition in the oil bath, also asuppresses another potential cause of some noise.

It Was heretofore noted that the condenser 25 is divided into two sections, and that the refri erant, after some cooling in the tube 21, is returned to the casing 2| through a line 35. This line is connected to one end of a length of tubing I I8, advantageously formed as a substantially flat spiral and disposed in the oil bath beneath the discharge coil I I1, as will readily be apparent from Figs. 3, 4., and 5. The other extremity of the tube H8 is directly connected to the line 36. leading to the other portion 28 of the condenser 25. For convenience, both ends of the tube H8 may be to the same side of the casing 2I for connection to the ducts 3'5 and 36. This arrangement provides an effective and simple method of extracting heat from the lubricant and compressor, and maintaining operating temperatures within desirable limits. Heat is transferred to the oil from the hot refrigerant passing through the discharge coil HI, and is extracted from the, oil by the relatively cool refrigerant returned from the condenser to flow through the coil I I8.

The cooling of the oil bath is very useful when the compressor 29 is assembled into a high side unit with a static condenser, that is, a system wherein an auxiliary condenser air fan and motor are omitted. Under heavy working loads, the over-all heat generation may overtax the capacity of the natural draft of cooling air, thus leading to excessive temperatures for motor and compressed refrigerant, With concurrent reduction in efficiency and risk of motor failure; It has. been discovered that, by recirculating compressed, but relatively cool refrigerantthrough the oil bath, a compressor temperature reduction may readily be effected which maintains themachine within desired temperature limits, and thus maintains a higher capacity. This method of heat extraction eliminates the necessity of a-stand-by auxiliary condenser fan and attendant controls, or a separate oil cooling radiator and circulating pump outside of the casing 2i While the section 21 of the condenser 25 is herein shown as being utilized .for the pre-cooling of the compressed refrigerant,

it should be understood that-a separate precooler may be used. It is;also apparentthat the pre-cooler section may be =made as large or as small as operating conditions may warrant, and will depend upon the desireddegre of oil cooling.

a through the axis of the piston 9!.

is enclosed by a lubricant pump cylinder casing i128, formed from a number of laminated plates which are welded together, and to the under side The normal oil bath levelis approximately at the bottom of the piston '9'I,'so that it can carry a lubricating film into the cylinder 99 as the piston reciprocates. Oil is supplied to the bearings for the motor 54 by a force feed pump, generally designated by the reference numeral I'2I in Fig. 3, which operates iii-unison with the reciprocation of the piston 9|. The pump effiuent is supplied to the bearings through an axial duct I22 in the shaft 59, which extends from the bottom or crank end 92 to a point just below the upper extremity, where it merges into a radial bore I23. A similar bore, not shown, located on the main shaft section just above the crank arm 93, supplies a portion of the lubricant in the duct I22 to a spiral groove I24 on the periphery of the shaft, to furnish-oil to the main and thrust bearings. The upper bore I23 communicates with an'aligned radial opening in the quill 6i, and the portion of oil discharging therethrough is splattered over the rotor 62 to aid in cooling. Thus, in addition to the cooling of the motor effected by the returning refrigerant, further cooling is obtained by the lubricant. As just noted, the oil is cooled by the pro-cooled com pressed refrigerant. The lubricant discharged through both quill 6| and spiral groove I2 3 drains to the bottom of the casting 55 for return through the aperture 61.

The operation of the pump I26, and its synchronization with the shaft 59 and piston 9!, will be more readily understood by reference to Figs. '1 to 9. The closed but hollow piston 9! is welded to the cylindricaland open-ended yoke 91, with their axes intersecting at right angles in a horizontal plane. The upper portion of the yoke cylinder is formed with an elongated slot 526 to receive the crank 92 and to accommodate its axial component of motion, while the lower portion of the yoke 91 is formed with an arcuate slot or port I21, which is disposed on the central diameter and is therefore intersected by a vertical plane The slot 421 of the yoke 91,'and are bored to provide a pump cylinder I29 whose head end communicates with the port I21. This formation of the yoke and pump cylinder assembly provides a sturdy but light weight construction, and also simplifies problems of fabrication.

The piston I3I for the cylinder I29 consists of a fixed horizontal pin screwed into a tapped opening in the head end of the block 85, whose axis is located in the vertical planepassing through the axis of the piston9I. This pin has a diameter somewhat less than the diameter of the cylinder I29, and, upon the suctionstroke, admission of lubricantto the cylinder'l29 is effected by leakage under suction pressure through the clearance gap. Dischargeof lubricant, of course, is throughthe port 621 in communication with the head end of the cylinder I29, the dash pot effect precluding significant reverse flow through the clearance gap during the compression stroke. The length of the pin I-3I is such that its inner end is guided in the cylinder I29 at all times.

The cylindrical crosshead 96, which is closed at its ends, is medially intersected by the bore 95 Which provides a bearing for the crank 92. The length of the crank is such as to terminate-at the innermost chord taken through the arcs of intersection of the bore and'crosshead periphery. Ac-

cordingly, there'is provided a small spherical segmental cavity or'well I32 (Fig. 3) below the end of the shaft 59 and the inner wall of the yoke 91, with which the shaft duct I22 is in constant communication. The crosshead 96 is also formed adjacent one end with a circumferentially milled slot I33, intersecting the bore 95, and extending arcuately for something less than ninety degrees. This slot is so located as to be aligned with the port E21upon the compression stroke, and displaced therefrom durin the suction stroke of the compressor.

In Fig. 7, the piston 9| is shown at substantially its mid position during the compression stroke, the direction of rotation being as shown by the arrow on the counterweight 94. At this point, it will be seen that the crosshead slot I 33 overlaps or registers with the port. I21 in the yoke 91, thus placing the lower end of the shaft duct I22 in fluid communication with the cylinder I29 through the well I32. Inasmuch as the motion of the yoke 91 is then toward the left, as viewed in Figs. 7'and 7A, lubricant will be discharged to the duct I22 by thecompressive eifect of the motion of the cylinder I 29 over the piston I3I.

At this particular instant, the motion of the crosshead is upward, as seen in Fig. 7, while the axis of the crank 92 is at a position of approximate intersection with the axis of the yoke 91. Accordingly, during the ensuing ninety degrees of rotation, the piston 9| and cylinder I29 will continue to move toward the left, to complete the compression strokes of both the refrigerant and the lubricant pumps. During such movement, however, the motion of the crosshead 96 is downward, and the slot I33 is so located, and of such width, that it will pass completely over the duct I 21, to cut off discharge therethrough as the end of the compression stroke is reached. At this moment, the crosshead is located substantially centrally in the yoke 91.

After the axis of the crank 92 has swept through the axis of the piston IN, the reciprocatory motion of the piston and yoke is reversed. The cylinder I29 is retracted from its piston I3 I, while the'piston 9| begins its motion to the right. During the first ninety degrees of rotative m0vement corresponding to these linear movements,

the crosshead 96 continues to move downwardly,

to attain the position shown in Fig. 8. The next ninety degrees of rotative motion from the position of Fig. 8 completes the suction strokes for both pumps, and reverses the motion of the crosshead to return it to its central location. Further rotation institutes the compression strokes, the slot I33 again realigning with the port I21 to open the discharge from the cylinder I29, and the parts returning to the positions of Fig. 7 to complete the cycle.

It will be seen that the lubricant feed pump I2I is of extremely simple construction, and it has but one moving part. The discharge valve control is effected through the crosshead and yoke assembly, and again no additional movable parts are required in addition to the essential components of the drive. It has been found that this lubricant pump will deliver ample quantities of oil to the motor for both lubricating and cooling purposes, and there is no significant leakage 'around the piston I 3| or the crosshead 99 on the compression stroke. 'Inasmuch'as the piston I31 is not in direct contact with the cylinder I29, there is no likelihood of wear to interfere with the efficiency of operation.

.It is believed that the functioning of the complete compressor has been made apparent as the detailed description has developed. The problem of providing high compressive capacity into a small unit is solved in part by locating the motor shaft diametrically of the casing 2|, and in providing a resilient suspension disposed at least in part axially of the casing and transversely of the motor assembly. This spring suspension also provides a metallic path to conduct heat to the casing walls. Other heat conducting media include the oil sprayed over the motor, the incoming refrigerant vapors, and the cooling coil H8 cooperating with the condenser 25.

It has been a very diflicult matter to build hermetic compressors on a low cost, high production, basis which would operate with an insignificant amount of noise. In the instant machine, the submergence of discharge and cooling coils, and utilization of built-in mufiiers, contribute to the solution of the noise problem, as also does the resilient suspension. The simplification of the structural details, and their coordination with each other, cooperate to maintain residual noise at a non-disturbing low level, and withal permit quantity manufacture at a low unit cost.

Obviously, many of the advantages of the invention may be obtained when utilizing only some of its improved features, and it will be also apparent that various modifications and changes may be made without departure from its principles. Accordingly, it is intended that the invention should not be restricted to the precise parts and complete combination as herein shown and described, but that it be accorded a scope commensurate with that expressed in the following claims.

I claim:

1. A hermetic refrigeration compressor comprising a sealed casing, a casting within the easing having a motor and compressor operatively connected thereto, spring means to support the casting in spaced relation to the casing walls, inlet and discharge ports for the compressor, an imperforate discharge line connected to the discharge port and extending through the wall of the casing, a suction line opening in the wall of the casing at a high point therein and in communication with the interior of the casing, a suction conduit in the casing having one end connected to the inlet port of the compressor and its opposite end disposed at a high point in the casing in spaced relation to the suction line opening, whereby refrigerant vapor to be compressed may circulate in the casing before entering the suction conduit, said suction conduit adjacent its open end being divided into a number'of openings each smaller than the total cross sectional area of the suction conduit to muille noise generated by the pulsation of vapors in said conduit.

2. A compressor comprising a supporting casting formed with a shaft bearing, a rotatable drive shaft mounted in the bearing, said shaft having a crank extending from one side of the bearing, a compressor cylinder block connected to the casting, a reciprocable piston mounted in the cylinder block, a Scotch yoke connection between the crank and piston, a lubricating pump cylinder formed in the yoke element of said Scotch yoke, a fixed pump piston mounted on the cylinder block and extending into the pump cylinder, an oil duct extending axially of the shaft and through the crank, said oil duct communicating with the bearing, a discharge port in the yoke element in fluid communication with the pump cylinder and adapted to be covered by the crosshead element of the Scotch yoke, and a slot formed in the crosshead element and intersecting the crank bore therein and adapted periodically to be aligned with and displaced from the discharge port as the cross head element reciprocates in the yoke element.

3. A compressor comprisinga supporting casting formed with a shaft bearing, a rotatable drive shaft mounted in the bearing, said shaft having a crank extending from one side of the bearing, a compressor cylinder block secured to the casting, a reciprocable piston mounted in the cylinder block, said piston having a yoke on the crankcase end thereof. said yoke having an axial slot and a radial slot in the periphery thereof, an oil pump cylinder secured to the periphery of the yoke and having a head end in fluid communication with said radial slot, said radial slot forming a discharge port for the pump cylinder, a crosshead reciprocably mounted in the yoke and having a bore therethrough, said crank being mounted in the bore and extending through the axial slot whereby the crank may rotate in the bore and reciprocate the crosshead in the yoke and the compressor piston in the compressor cylinder block, a fixed pump piston on the crankcase end of the cylinder block extending into the pump cylinder, an axial oil duct formed in the shaft and extending from the crank end thereof to said bearing, said duct thereby being in communication with the crosshead bore, and a peripheral slot formed in the crosshead and in-- tersecting the bore at one side thereof, said crosshead being so positioned in the yoke that the peripheral slot therein registers with the radial slot in the yoke when the yoke pump cylinder advances over the pump piston, and is displaced therefrom to close the radial slot when the pump cylinder is retracted.

4. A compressor comprising a supporting casting formed with a shaft bearing, a drive shaft rotatably mounted in the bearing and having a crank on one end extending therebeyoncl, a compressor cylinder block secured to the casting and formed with a cylinder, a piston reciprocably mounted in said cylinder, a fixed pump piston secured to the crankcase end of the cylinder block, a driving connection between the compressor piston and the crank, a pump cylinder operatively carried by said driving connection for reciprocable movement over the pump piston as the compressor piston is reciprocated, said pump piston being of'less diameter than the pump cylinder to provide a clearance gap therebetween, said pump cylinder and piston being adapted to be submerged in an oil bath whereby oil may flow into the piston through said gap, a discharge port for the pump cylinder at the head end thereof, an axial oil duct through the crank and shaft communicating with the shaft bearing, and valve means controlled by the rotation of the crank to place said pump cylinder discharge port in communication with the shaft duct upon compressive movement of the compressor piston and to close said pump discharge port upon reverse movement.

5. A refrigeration high side comprising a hermetic compressor including a casing having an interconnected motor and compressor sealed therein, a pool of lubricant in the casing, pump means for circulating the lubricant over the motor to extract heat therefrom and transfer said heat to the pool, a suction inlet in the casing adjacent the motor to admit relatively cool refrigerant vapors into contact with the motor to extract heat therefrom, a closed discharge line extending from the compressor through the casing wall, an imperforate cooling coil in the casing andthe pool of lubricant therein, said coil having inlet and outlet ends projecting through the casing, a condenser connected to the discharge line, exteriorly of the casing to efiect cooling of the compressed refrigerant, said condenser having its discharge end connected to the inlet of the cooling coil, whereby cooled refrigerant may extract heat from, the pool of lubricant and thereby the hermetic compressor, and a second condenser having its inlet connected to the outlet of the coil, whereby the heat absorbed by compressed refrigerant circulating through the coil may be dissipated.

JENS TOUBORG.

REFERENCES CITED The following references are of record in the file of this patent:

Number 12 UNITED STATES PATENTS- Name Date I Paulsen Aug. 31, 1920 Bourne Nov. 22, 1932 Philipp Feb. 14, 1933 Bixler Jan. 21, 1936 Bixler Sept. 20, 1938 Steenstrup- Sept. 20, 1938 Buchanan Dec. 13, 1938 Touberg Feb. 7, ,1939 Philipp Feb. '7, 1939 Simons Mar, 5, 1940 Philipp Jan. 14, 1941, I-Iigham ,June 16, 1,942 Philipp Oct. 27, 1942, Smith Mar. 2, 1943 Schlumbohn Dec. 14, 1943 Touborg Nov. 28, 194 1 Hintze Mar. 12, 1946 Heitchue Mar. 1, 1949

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