US2427638A - Compressor - Google Patents

Description

W 5, W47, E. F. VILTJER ETAL 2,427,533

COMPRES SOR Filed Aug. 16, 1944 4 Sheets-Sheet 1 L A R E T m V F 5 COMPRESSOR Filed Aug. 16, 1944 4 Sheets-Sheet 2 E. F. VILTER ETAL 2,27,38

COMPRESSOR Filed Aug. 16, 1944 4 Sheets-Sheet 3 %p&.. M, 194576 E. F. VILTE ETAL COMPRESSOR 4 sheets-sheet 4.

Filed Aug. 16, 1944 llllllvl Patented Sept. 16, 1947 COMPRESSOR Ernest F. Vilter, William E. Michener, Km L. Kraatz, Max E. Rucss, and Charles G. Bach. Milwaukee, Wis., assignors to The Viltcr Manufacturing Company, Milwaukee,

poration of Wisconsin Application August 10,1944; Serial No. 549,736

Our invention relates in general to improveecisims. (chase-20's) ments in the art oi fluid compression, and re- .0! the invention are as follows:

To provide an improved multiple cylinder compressor of variable capacity which is extremely compact in structure and quiet in operation, and all important parts of which are readily accessible for inspection.

To provide a relatively light but strong compressor assemblage having relatively large capacity but occupying minimum space, and which may be used advantageously to handlevarious kinds of refrigerants and other fluids.

To provide an improved reciprocating piston compressor all parts of which may be easily manui'actured, which may be conveniently assembled and dismantled, and similar parts of which are interchangeable.

To provide a compressor for refrigerant or the like, the various bearings of which are abundantly and eiiectively lubricated at all times, without permitting undesirable escape of lubricant with the fluid being pumped.

To provide a relatively high speed compressor the various elements of which are balanced so as to insure smooth and silent operation, and which is operable with minimum power consumption.

improved unloading mechanism therefor which is readily manipuiable to vary the output or capacity without undesirable shock or vibration.

To provide an improved lubricant circulating system for compressors or the like, wherein sufficient oil is constantly supplied to all parts requiring lubrication, while excess lubricant is bypassed to the supply chamber.

To provide an improved compressor lubricating assemblage wherein full pressure lubrication for the crank, connecting rod, and piston wrist pins is provided through accurately formed passages. and in which the oil lines are readily accessible for inspection.

To provide improved compressor valve mechanism in which valves of ample size and simple To provide an improved fluid compressor and Wla, a cor- 2 construction are utilized, and wherein the valves are conveniently accessible and replaceable.

To provide a compact but durable crank shaft and connecting rod assembly for reciprocable piston multiple cylinder compressors, wherein expansion and contraction of elements due to varying temperatures is eil'ectively compensated for.

To provide an improved multi-cylinder compressorwhereln the cylinders are disposed to provide for compactness and smooth operation, and in which the driving torque is minimized.

To provide various other improvements in the details 01' construction of fluid compressors, whereby the costs of manufacture and maintenance are reduced to a minimum. while the efficiency or operation is enhanced to a maximum.

These and other specific objects and advantages or the invention will be apparent from the following detailed description.

A clear conception of the several ieatures constituting the present improvement. and ot the mode of manufacturing and operating compressors built in accordance with the invention, may be had by referring to the drawings accompanying and iorming a part 0! this specification wherein like reference characters designate the same or similar parts in the various views.

Fig. 1 is a longitudinal vertical section taken centrally through our improved compressor, but showing some of the internal parts in elevation;

Fig. 2 is a part sectional end elevation oi the improved compressor, the section having been taken vertically and transversely through one or the cranks, cylinders, and the crank case;

Fig. 3 is an enlarged central longitudinal section taken through the lubricating oil circulating pump of the compressor;

Fig. 4. is an enlarged section taken longitudinally of the compressor through one of the capacity controls which are associated with each of the inclined sets or pairs of cylinders; and

Fig. 5 is a transverse section through the assemblage oi Fig. 4, taken along the line 5-! thereof.

While our invention has been shown and specifically described herein in connection with a six-cylinder V-type refrigerant compressor, it is not our desire or intention to thereby unnecessarily restrict the scope or the utility of the invention.

Referring to the drawings, the improved gas compressor assemblage shown therein comprises in general, a main casing having a lower crank case i and upper inlet and discharge chambers I, 9 respectively. separated from each other by a partition l3; anti-friction or roller bearings ll,

l2 carried by the opposite ends of the main casing adjacent to the crank case I: a crank shaft l2 rotatably ioumalled in the bearings ll, l2 and having an outer end i4 adapted to be drivingly connected to an electric motor or other source of power; two central upright cylinders i5 having their axes disposed in the vertical longitudinal central plane of the crank shaft l4 and spanning the inlet chamber 3; two pairs of oppositely inclined cylinders i8 radiating from the crank shaft axis on opposite sides of the vertical cylinders i5, and also spanning the intake cham- 'ber 8; a piston I'l reciprocable within each of the cylinders it, It by means or a hollow connecting rod i8 coacting with an adjacent crank it of the crank shaft l3: anannular inlet valve 20 interposed between the outer end of each cylinder I 5, l6 and thecommon suction chamber 8; an annular discharge valve 2i interposed between the outer end of each cylinder i5, i8 and the common outlet chamber 9; improved unloading mechanism coacting with theinlet valves 20 of the inclined cylinders It only; an improved lubricant circulating pumpassemblage coacting with the housing andsupport 22 of the crank shaft bearing Ii; and suitable strainers for removing lubricant from the gas which is to be compressed, and impurities from the oil, being circulated by .the pump assemblage.

'The main casing of the pump may be formed of a single integral casting having relatively large endopenings within which the bearing housings and supports 22, 23 are secured, and also having large opposite side openings normally closed byrectangular cover plates 24; and the crank case I is provided withlongitudinal ribs 25 and with an abundant supply of lubricant such as anoil basin 26, a shown in Fig. 1. The medial portion of the main pump casing also has anintegral partition 21 separating the crank chamber from'thcsuction chamber 8, and the suction anddischarge chambers 8, 9 are provided with gas inlet andoutlet connections 28, 29 respectively. The

' sleeves which form the cylinders l5, iii are snugly fitted within bores in the partitions i0, 21; and the outer end of each cylinder IS, I6 is provided withaclosure head 30 with which thevalves 20, 2| are associated. Theseheads 30 are normally held in place by means of stiff compression springs 3| coacting therewith and withremovable closure caps 32 secured to the main casing bycap screws 33 as illustrated in Figs. 1 and 2; so that all portions 01' the interior of the main pump casing are readily accessible through the various openings therein which are normally sealed by thesupports 22, 23 and thecover plates 24, theconnections 28, 29, and theclosure caps 32.

The crank shaft i3 which is rotatable within the anti-friction bearings ll, l2 and the outer end l4 of which is adapted to be driven at any desired speed by a motor or the like. has two op-. positely directed cranks l9, andcounter balancing weights 34 adjacent to the bearings ll l2. The interior of the shaft i 3 is provided with a longitudinallubricant conducting passage 35 one end of which is sealed by aplug 36, and the opposite end of which communicates through one or more small radial ports 31 with a sealedchamber 38 formed in thebearing support 23,. while the crank pins I 9 are also provided withports 39. leading to the adjacent bearings of the connect-' ing rods i8, as depicted in Figs, 1 and 2. Thechamber 33 is enclosed by acover plate 40 and an inner plate 4| andsealing rings 42, 43 are pressed shown in dot-and-dash lines in Fig. 1.

into scaling engagement with theseplates 43, 4| by means of aspring 44, so that lubricant admitted to the chamber 2| under pressure, must pass through the ports 31 into thepassage 35 and from this passage through theports 32 to the lower bearings of the hollow connecting rods II. The upper ends ofthe hollow connecting rod i3 coact with wrist-pins 45 which are secured to the adjacent pistons H by setscrews 43, and the excess lubricant delivered from theports 33 flows through the rods l8 and lubricates the upper bearings and pins 45. All of the crank and connecting rod bearings are thus constantly and abundantly lubricated by oil under pressure, and the bearings l I, I2 are likewise well lubricated by oil splashed from thecrank case basin 28 and by the improved oil pump assemblage which will subsequently be described.

Lubricant under pressure isv constantly circulated from the crankcase oil basin 28 by means of an improved oil pump assemblage such as shown in detail in Figs. 1 and 3, and which is associated with thebearing support 22. The improved oil pump assemblage comprises in general a positive displacement rotary pump provided with a rotor 41 revolvable within the bore of aplate 48 secured to thebearing support 22, by means of a driving shaft 49 having a flat end coacting with a slot 50 formed in the adjacent end of the crank shaft i3: and oil confining chambers 5| 52 communicating with the pump discharge. The pump illustrated is of a well known type, and may be replaced by other rotary positive displacement types, and thesuction line 53 of this oil pump communicates with the crankcase oil basin 26 through a strainer 54 and past a,needle control valve 55 as indicated in Fig. 1. The pressure oil chamber 5! is exposed to 9. flexible diaphragm 56 held in place by a peripheral snap ring 51 and having a small oil delivery hole "58 in the upper portion thereof, communicating with the adjacent main bearing H, see Fig. 3: and the pump shaft bearing is vented through a groove 59 in the bearing sleeve 60, and through an opening 5i communicating with the adjacent 4 pressure chamber 5i. Theopposite pressure chamber 52 coacts with the chamber 5i to balance the pressure acting upon the rotor 41, and is provided with a, drain plug 62 and with a.strainer 63 through which oil under pressure is constantly delivered to agage 64 andpipe line 65 leading into the upper portion of thechamber 38 as In this manner an abundance of oil under pressure is constantly delivered to the various bearings during normal operation of the compressor and the oil is returned by gravity to thebasin 26; and thestrainers 54, 63 maintain the circulating oil in clean condition.

As previously indicated, each of the compressor cylinders l5, I6 is provided with annular inlet anddischarge valves 20, 2|, associated with itscylinder head 30, and these valves are normally urged toward their seats by means of helical spiral springs 56, of well known construction. In order to prevent oil or other liquid from entering the cylinders l5, l6, two liquid removing strain=ers 61 are interposed between theinlet connection 28 andthesuction chamber 8, and a safety relief valve 68 is also interposed in the partition l0 between thesuction chamber 8 and the discharge chamber 9. This safety valve 68 may be adjusted so as to open automatically when the pressure in the discharge chamber 9 reaches dangerously high predetermined values, from the exterior of the main pump casing, through an opening normally sealed by aremovable cap 88 as shown in Fig. 2; and the strainers 81 are tubular and extend throughout the major portion of the length of the suction chamber between the central cylinders l8 and the inclined cylinders ii. The oil and other liquid removed from the gas by the strainers 81 flows downwardly along the inclined portions or thelower partition 21 to troughs 68 located below the inclined cylinders l8, from whence it may be removed or drained into the crank case basin 2! pastremovable plugs 18 one of which is shown in Fig. 2.

All of the pump cylinders l8, 18 are normally adapted to receive the gas through the strainers 81 from thecommon suction chamber 8, and to deliver the compressed gas to thedischarge chamber 8 past their respective discharge valves 2| but as previously indicated, the inclined cylinders l8 are provided with improved automatic unloading mechanisms for making them either active or inactive in accordance with the demand for compressed gas. One of these unloading assem-- 'blages is shown in detail in Figs. 4 and 5, and it is to be understood that one of these unloading rigs for controlling the compressor capacity, is applied to each parallel set of the inclined cylinders I8, and that the unloaders are independently operable so as to make either one, two, or three parallel sets of the cylinders I 5, I6. either active or inactive depending upon the demand.

Each of the improved unloaders illustrated in Figs. 4- and 5, comprises a series of parallel pins 1i slidable through openings in a medial flange 12 of each.,cylinder i8, and having their upper ends cooperable with theadjacent suction valve 28 while their lower ends are firmly attached to aring 18 slidably embracing the lower portion of the corresponding cylinder I S; a series of leaf springs Id interposed between each fixed flange l2 and theadjacent ring 18 for constantly urging the pins ii away from thevalves 20; amotion transmitting bracket 78 slidable between each parallel set of cylinders i6 along a. central bifurcated fixedpost 18 secured to a stationary plane reaction plate ii, and having contact elements i8 engageable with diametrically opposite portions of the two adjacent guide rings 73; a wedge yoke l8 having twowedges 80 at its extreme ends, each of which has a lower roller 8i engageable with the fixed plate 71 and anupper roller 82 cooperable with awedge surface 88 formed on the movable bracket 15; and aplunger 88 slidable within anauxiliary pressure cylinder 85 and havingastem 86 pivotally connected to the medial portion of the correspondingwedge yoke 19 by a pin 81. Each of thecylinders 85 is communicable past a solenoid actuatedvalve 88 and through aport 89, with themain suction chamber 8, and through another port 90 with themain discharge chamber 8; and each plunger 84 is adapted to be moved toward the leftas viewed in Fig. 4, by a helical compression spring 9i so as to close theport 80 when the pressure within thecylinder 85 drops belows a predetermined maximum. The extent of travel of each plunger 84 may be varied by adjusting ascrew 88 associated therewith, upon removal of a plug 84. Eachvalve 88 may be opened so as to connect thecorresponding cylinder 85 with thesuction chamber 8, either automatically or with the aid of a push-button switch 92, and when avalve 88 is opened, thecorresponding spring 8| will become quickly effective to raise the two correspondingsuction valves 20 through the pins ll,collars 18,

yoke wedge 18 and plunger ll, thereby unloading the corresponding pair of cylinders l8. However, it thevalves 88 remain closed when the discharge pressure in thechamber 8 is high. the pressure within thecylinders 85 will be suflicient to overcome the corresponding spring pressures, and the plungers 84 will then be held in the position shown in Fig. 4 subjected to discharge pressure through theports 88, so that thesuction valves 28 will be under the normal influence oi thesprings 88 coacting therewith. It should be noted that since the two central upright cylinders ii are not provided with an unloading device, these will always be active, but the two sets of inclined cylinders ii are subject to either simultaneous or successive unloading and loading, depending upon the demand for compressed gas.

.During normal operation of our improved compressor, the'crank case basin 2| should be provided with an abundant supply of clean lubricant such as high grade oil, and all closures should be tightly sealed. When high speed rotary motion is imparted to the main crank shaft l3 through its outer end l4, the lubricating pump rotor 41 will be constantly revolved to properly circulate oil under pressure through the various bearings, and the pistons i! will be rapidly reciprocated within their respective cylinders l8, l8. If the discharge pressure within thechamber 8 is low, due to large demand for compressed gas, the unloading devices associated with the inclined cylinders It will be inactive as shown in Fig. 4, and all of the 'six cylinders l8, l8 and pistons II, will function to deliver compressed gas to thedischarge chamber 8 anddelivery line 28. The solenoid actuatedvalves 88 of the unloading devices will then be closed and discharge pressure will be maintained within theauxiliary cylinders 85 through the ports to hold theplungers 88 to the right as shown in Fig. 4, and to thereby permit the leaf springs 14 to retract the pins H from the zones of action of thesuction valves 28. However, if the demand for compressed gas decreases, thevalves 88 will automatically open either simultaneously or successively, depending upon the setting of the stop screws 88, and this opening of thevalves 88 will cause the pressures within thecylinders 88 to quickly drop through theports 88 thus permitting the springs 8i to force thewedge rollers 8 i, 82 to the left as viewed in Fig. 4, and to thereby raise thecollars 13 and pins ll so as to lift thesuction valves 28 and thus unload the corresponding cylinders l8. Subsequent increase in the demand for compressed gas will again cause thevalves 88 to close either simultaneously or successively, and this closing of thevalves 88 will be promptly followed by restoration of the collars I8 and pins H to inactive position, so that thesuction valves 28 will again be free to function normally. It will thus be noted that the compressor functions automatically and quickly to meet varying demands for compressed gas, and that proper lubrication is maintained at all times.

From the foregoing detailed description it will be apparent that our present invention provides an improved compressor assemblage which may be operated at relatively high speed to meet varying desirable conditions of operation, and to automatically maintain desirably high pressures in the discharge line. While the improved compressor is especially useful in connection with refrigerating apparatus, it may be used for the compression of air and gases of various types, and by virtue of the improved construction of the assemblage with numerous removable covers and closure plates, the machines may obviously be readily assembled. dismantled or inspected with minimum effort. The improved oil pump assemblage maintains eflicient lubrication of all working parts at all times, and thestrainers 54, 63 function to prevent foreign matter from reaching the bearings. The strainers 81 efl'ectively separate the oil from the gases being delivered to the cylinders, and this oil may be quickly returned to the crankcase basin 28 for re-use. The improved lubricant circulating pump is effectively balanced and is automatically driven by the revolving crank shaft, and all joints are thoroughly sealed against possible escape of lubricant and gas. The improved unloading device functions to automatically unload the successive valves and to restore these valves to normal operation condition when unloading is not desired, and by providing three sets of cylinders and .two unloading devices, either one, two, or three sets of the cylinders may be made active or inactive under varying conditions of operation. The improved unloading device besides being extremely simple and compact, is also reliable in operation, and insures simultaneous operation of the set of cylinders IS with which it is associated. This unloading device while being applied to only two sets of the cylinders l6, may also be applied to the third set of cylinders IE it so desired, and the pressure relief valve 68 positively prevents the establishment of excess pressure. within the discharge chamber-9 thus enhancing the safety of operation of the unit.

The improved oil pump and diaphragm assemblage is relatively important since it permits'the pump rotor to draw oil from an external container in order to add lubricant to the machine while in operation. The diaphragm and the vent hole in the upper portion thereof permits the pump to draw oil from such outside source against the normal crank case pressure, and prevents gas from going through the pump bearing and into the pump pressure chambers under such operating conditions. By providing a structure such as illustrated in Fig. 3, the pump bearing is sealed with oil by gravity during the time that oil is being drawn in from the outside'oi' the machine, and this improved assemblage has therefore proven highly advantageous in eliminating oil pump difficulties. The improved compressor with its lubricating and unloading systems, has gone into highly successful commercial use and is obviously extremely compact considering its great capacity and may be manufactured and sold at moderate cost.

It should be understood that it is not desired to limit this invention to the exact details of construction or to the precise mode of use, herein shown and described, for various modifications within the scope of the appended claims may occur to persons skilled in the art.

We claim:

1. In a compressor, an upright cylinder and oppositely inclined cylinders on opposite sides of said upright cylinder, a casing forming segregated suction and discharge chambers common to and surrounding all of said cylinders, a pressure relief valve interposed between said chambers, suction and discharge valves interposed between each cylinder and said chambers respectively, a piston reciprocable in each cylinder, and an independent unloading device for the suction valves of said oppositely inclined cylinders only, each of said devices comprising a ring slidable along the adjacent cylinder and havin pins cooperable with the adjacent suction valve to hold it open, leaf springsnormally urging said ring and pins away from said valve, wedge rollers for compressing said springs, and a plunger subjectable to suction pressure within said suction chamber to move said wedge rollers to open said valve.

2. In a compressor, a casing having an enclosed crank chamber and a plurality of cylinders radiating from said chamber, a piston reciprocable within each of said cylinders, a crank shaft rotatable in said chamber, connecting rods operatively connecting said shaftwith said pistons, a liquid pump direct connected to an end of said shaft for delivering lubricant under pressure from said chamber to said pistons and cylinders, and a flexible diaphragm interposed between said chamber and said pump and having a flexible diaphragm interposed between said chamber and said pump and having a vent opening connecting the interior of the pump with the chamber, and conduit means connecting the shaft bearing of said pump with the internal pump chamber exposed to said diaphragm, said conduit means being completely submerged in lubricant at all times.

4. In a compressor, an upright cylinder and oppositely inclined cylinders on opposite sides of said upright cylinder, a casing forming segregated suction and discharge chambers common to and surrounding all, of said cylinders, a pressure relief valve interposed between said chambers, suction and discharge valves interposed between each cylinder and said chambers respectively, a piston reciprocable in each cylinder, and an independent unloading device for the suction valves of said oppositely inclined cylinders only, each of said devices comprising a member slidable along the adjacent cylinder and having elongated parallel elements cooperable with the adjacent suction valve to hold it open, springs normally urging said member and elements away from said valve, wedge rollers for compressing said springs, and a plunger subjectable to suction pressure within said suction chamber to move said wedge rollers to open said valve.

5. In a' compressor, an upright cylinder and oppositely inclined cylinders on opposite sides of said upright cylinder, a casing forming segregated suction and discharge chambers common to and surrounding all of said cylinders, a pressure relief valve interposed between said chambers, suction and discharge valves interposed between each cylinder and said chambers respectively, a piston reciprocable in each cylinder, and an independent unloading device for the suction valves of said oppositely inclined cylinders only, each of said unloading devices comprising an annular member slidable along the adjacent cylinder and cooperable with the adjacent suction valve to hold it open, resilient means normally urging said member away from said valve, wedge rollers for compressing said resilient means, and

means subjectable to suction pressure within said suction chamber to move saidwedge rollers 1 to open said valve.

6. In a. compressor, a'unitary casing,having therein an enclosed crank chamber and a plurality of cylinders radiating from said chamber, a piston reciprocable within each of said cylinders, a crank shaft rotatable within said chamber,

connecting rods operatively connecting said shaft with said pistons, a liquid pump direct connected to an end of said shaft for delivering lubricant under pressure from said chamber to said pistons and cylinders, and afiexible diaphragm having opposite sides exposed to said chamber and said pump respectively and also having a vent opening connecting the interior of the pump with the crank chamber.

ERNEST F. VILTER. WILLIAM E. momma. KARL L. KR-AATZ.

MAX E. RUESS. CHARLES G. EACH.

- 10 REFEnENcEs mm The following references are of record in the 5 me 01 this patent:

UNITED STATES PATENTS Number Date McCormack Jan. 5, 1932

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