US1823910A - Apparatus for displacing fluid - Google Patents

Description

' Sept. 22, 1931. v. w. MORAY APPARATUS FOR DISPLACING FLUID Filed Jan. 9. 1930 3 Sheets-Sheet 1 Vz'rqil WMoray BY Sept. 22, 1931. v. w. MORAY 1323,91 0

APPARATUS FOR DISPLACING FLUID- Filed Jan. 9. 1930 3 Sheets-Sheet 2 INVENTOQ 4, ATTORNEY p 1931. v. w. MORAY 1,823,910

APPARATUS FOR bIsPLAcINc FfluID Filed Jan. 9. 1930 3 Sheets-Sheet 3 IINVENTOR Patented Sept. 22, 1931 E-E STATES vrnerr. WILLIS MOBAY, on NEW YORK, n. Y.

, ArrAnA'r s ron nIsrLAoING groin Application filed Januaryft), 1930. Serial No. 419,543.

My invention relates to machines for compressing gases such as pumps for air and other gases, internal combustion engines, suction and vacuum pumps and Diesel engines.

5 It has long been common commercial practice to design compressors to'operate with constant speed of the crank shaft driving the piston or pistons. This gives a curve of speed v of the piston which we may call thenormal piston speed characteristic. The suction and compression strokes are of equal duration and the variation of piston speed between zero at the top, through maximum at an intermedi- I ate position and zero at the bottom is similar 1:3 for the up and down strokes. I have discovered that by causing a slowing down of the piston speed with respect to what I term the normal piston speed characteristic during the compression stroke and by" a reciprocal speeding up during the suction stroke, a gain in efficiency maybe obtained. This variation from the normal piston speed characteristic affects the power consumed in com? pressing a charge of gas, the mean speed ati which a compressor may be operated, and the values of pressure at which compressors may be made to operate in one or more stages of compression.

My invention consists in improved meth outs and apparatus for compressing gas involving this variation from the normal piston speed characteristic.

The general object of my invention is to' improve the eiiiciency' of compression apparatus. Another object is to provideineans for decelerating the speed otmovement of a compressor piston or like member during all or part of the compression strokesoas to.

obtain a more effectiveutilization of the cyl- 40' inder walls of the compressorfor transferring the heat of compression medium during compression. Another object is to provide means permitting an in crease of the number or revolutions a compressor may operate without'loss' of thermodynamicefficiency. Still another object of the invention istolprovidemeans forming a driving connection between a com pressor and a power sour'cef operating to. equalize theload on the power source, proto the cooling at which tecting it from undue stress and at thesame time permitting the use/of a light fly wheel.

'- Further objects and the nature and advan tages of my invention will become apparent from consideration of the following descrip tion taken in connection with the accompanying drawingsshowing preferred forms of apparatus for carrying out the invention and forming part of this specification.

Referring to the accompanying drawings: Fig 1 is a cross-sectional view of acorn: pressor embodying the invention connected to be driven by an electric motor;

Fig. 2 is across-sectional view-taken on line 2+2 of Fig. 1 and shows more'or less diagrammatically one position of the crank mechanism;

Fig. 2a shows the mechanism shown in Fig. 2 when one of the cranks has beenrotated throughan'angle of 90"degrees; Fig. 2? shows the mechanism shown in Figs. 2 and 2a but with this crank rotated through an additional 90 degrees; 9 t Fig. 20 shows the mechanism shown in Figs. 2, 2a and 2?) but with this crank rotated through an additional 100 degrees;

Fig. 3 is a cross-sectional'view taken on positions of tlIQ'IG-IllLlIldGI of crank mechanismcorre'spondin'g tothe positions of the crank mechanism shownin Fig. 6 Fig. 7 showstherelativepositionsof the mechanism shown in Fig. [6 when one of the cranks has been "rotated th-rough9O degrees. 1 Fig. 7a shows the eiiect of this-rotation upon the mechanism shown'in Fig. 6a; Fig. 8 showsthe relative positions of the mechanism shown in" Figsfi and 7 when this ures, reference character 10 designates the base of a compressor unit on which is mounted an electric motor 11 and a compressor 12. The compressor comprises a crank case 13 and a cylinder 14. The cylinder has double walls between which are spaces 15 for cooling water, suitable connections being provided for flow of cooling water through the cooling jacket. The piston cham- 7 her 16 is formed withinthe inner'cylinder wall and a piston 17 moves up and-down therein. Y

The cylinder head 18 is provided with suction and discharge conduits '19 and 20 re? spectively, and with suction and discharge valves 21 and 22 respectively. A water jacket 15a is provided in the cylinder head and is stepped as shown in order to provide a greater surface for the transmission of heat from the gases within the cylinder to water in the cylinder in the cylinder head. The piston 17 is attached to connecting rod 23 which is secured to crank shaft member 24 mounted in bearings 25 and 26. The piston is recessed at 17 a so as to receive the stepped water acket 15a and thus obtain a minimum clearance. The recess 17a is complementary to the stepped jacket 15a.

To the end of shaft member 24 isattached a crank 27. The end of shaft member 24 and crank 27 are splined so that crank 27 may have a variety of selective positions on shaft memb'er'24. A crank 28 is attached to a shaft member 29. Shaft members 24 and 29 are mounted out of alignment. Shaft member 29 is mounted in a bearing 30 which is carried on a plate'3l. Plate 31 is secured to the crank case housing by a plurality of bolts 32, equally spaced so'thatplate 31 can have a variety of selective positions on the crank case housing. The passage for shaft member 29 is eccentrically .disposed on plate 31 so that different positions of plate 31 give different positions ofshaft member. 29

' with respect to the crank case housing. and

with respect to shaft member 24.

Between shaft member 29 and motor shaft 33 is ashaft member 34 connected, to member's 29 and 33 byuniversal joints 35 and 36. This permits the adjustment of vpositionof shaft member 29 without'disturbing the posi-.

tion'of the motor. Afly-wheel 37 is attached to shaft 29. Connected between cranks 27 and 28 is a link 38.

The operation of this embodiment of my invention is as follows:

Motor 11 drives shaft 29 and crank 28 attached thereto at a substantially constant rate. That is to say crank 28 passes through equal angles during equal intervals of time. Crank 28 drives link 27 which in turn drives the shaft member 24. The relation of parts is such that while crank 28 rotates at constant speed, shaft member 24 does not rotate at constant' speed but takes a much longer time for the up stroke or working stroke than for the down stroke. This is due to the eccentric arrangement of cranks and links. The relatively slow motion of the compression stroke permits a greater interval of time in which the heat of compression may pass to the cooled cylinder walls than would be the case with a compressor of the conventional type operating at the same mean speed. As a result the temperature of the charge of gas is reduced during the compression stroke and hence, in an ultimate sense, less power is required to compress a charge of gas to a given effective pressure.

Heat is generated inv compressing gas. This heat, if not conducted away, or if conducted away at too slow a speed, serves to expand the gas internally. This expansion due to heat is lost effect because there is a corresponding loss after the gas l aves the compressor, for example, in an after-cooler for an air compressor. This loss is avoided in proportion as the heat is taken away during the compression. Two factors enter into this matter, namely surface ofheat dissipation and time of heat dissipation. My invention relates primarily to time of heat dissipation. I increase the time of the compression stroke relative to the suction stroke and thus obtain a better heat conduction, thereby lowering the compression pressure toward that ultimate pressure which obtains in the gas as a result of compression.

I combine with this'the factor of extended surface in order to further increase the efficiency, this being in the form, as shown, of extended surface of the cylinder head.

In Fig. 2 is shown the positions of crank 28,'link 38, crank 27, crank shaft 24 and connecting rod 23 when theconnecting rodis at the lower end of its stroke. In Fig. 2a crank 28 has been rotated through an angle of 90 degrees. This rotation of crank 28 causes crank shaft 24, driven by link 38and crank 27 to rotatejsomewhat less than 90 degrees. In Fig. 2b crank 28 has been rotated 90 dcgrees from the position shown inF 2a. This rotation; of crank 28 has caused crank shaft 24 to rotate but approximately 45 de grees from the position shown in Fig. 2a. In Fig. 2c crank 28 has been rotated 100 degrees from theposition shown in Fig. 2b. This rotation of 100 degrees has caused crank shaft 24 to rotate to a vertical position where the connection rod 23 is at the upper end of its stroke. A further rotation of degrees of crank 28 from the position shown in Fig. 20 to the position shown in Fig. 2 causes crank shaft 24 to rotate through an angle of 180 degrees. Thus it will be seen that the motion of the connecting rod 23, and hence the piston attached to the upper end thereof is much slower during the compression or up stroke than during the suction or down stroke as crank 28 passes through approximately .280. degrees in order to turn crank. shaft 24 through'lSO degreesduring the compression stroke while crank 28 turns through only 80 degrees in order to rotate crank shaft 24 through 180 degrees during the suction stroke. The ratio of the speeds of connecting rod 23 on the compression and suction strokes respectively, may be varied by varying the eccentricity of shaft 29 with respect to crank shaft 24. This may be done by rotating plate 31 as has been previously explained. Fur-;v

ther adjustment is provided by the splined shaft on which crank 27 may be turned to any position relative to the compression crank. Thus the slowest speed of the piston may be made to occur at any point. desired.

If it is desired to obtain a greater diiference in the ratio of the speeds of the con necting rod during compression and suction strokes than will be possible with this device, two such devices may beconnected together. Such an arrangement is shown in Fig. 4 where similar partsshown in Fig. 1 are represented by like reference characters. Motor 11 and compressor 12.are mounted on a common base 10. Compressor 12 may be similar to the compressor shown in Fig. 1 and hence a description thereof need not be repeated. The crank shaft 24 of the compressor has splined to one end thereof a crank 40 to which is attached a link 41, the other end of which link is attached toa crank 42 mounted on one end of an. intermediate shaft 43. Shaft 43 is rotatably supported in a bearing 44 carried by a plate 45. Plate 45 is secured to the compressor housing by means of a. series of bolts 46 passing through holes near the circumference of the plate. Bearing 44 is eccentrioally mounted on theplate so that when plate 45 is adjusted with'respect to the compressor housing by removing bolts 46 and turning the platethe eccentricity of shaft 43 with respect to crank shaft 24 is varied. Splined to the other end of intermediate shaft 43-is a crank 47. A link 48 is pivotally attached to crank 47 and toa crank '49 mounted on a driving shaft 50. Shaft 50 is carried in a bearing. 51 in the compressor housing and is attached by means of a coupling 52 to the shaft 33 of motor 11.

spectively, show the relative positions of the various members for different positions .of the driven crank 49. Figs. 6, 7, 8 and 9 show the positions of cranks 49 and 47 and link48 while Figs. 6a, 7a, 8a and 9a show corresponding positions of crank 42, link 41, crank shaft 40 and connecting rod 23. The figures are divided in this way, that is into Figs. 6 and Get, for instance, in order to more clearly show the positions ofthe various members than would be possible if. Figs." 6 and 6c, for instance, were to be combined in one figure.

,InFig 6 is shown the position of crank 49 which corresponds to the lowermost position of connecting rod 123, which is shown in Fig. 6a.. In" Fig. 7 crank 49 has been rotated through an angle of degrees from the position shown in Fig. 6 This rotation of crank 49 has caused crank shaft 24 to rotate through an angle somewhat greater than 90 degrees. In Fig. 8, crank 49 has been rotated through an angle of 90 degrees from the position shownin Fig.7. This rotation of crank 49 has caused crank shaft 24 to rotate considerably less than 45. degrees from the position shown in Fig. 7a. In Fig. 9 crank 49 has been rotated 155 degrees from the position shown in Fig. 8.- This large angle of rotation of crank 49 has caused crank shaft 24 to rotate approximately 45degrees to a vertical position. Crank 49 in the position shown in Fig.9 is only approximately 23 degrees from the position shown in Fig. 6 and hence a rota tion .of crank 49 through. 23 degrees from the position. shown in Fig. 9 will cause crank shaft 24 to rotate through an angle of 180 degrees or from the position shown in Fig. 9a to that shown in Fig. 6a.

Thus it will be seen that the compression stroke of connecting rod 23' is very much pound arrangement the speed of the piston may be readily regulated to-suit the variations in pressure occurring durlng the compresslon stroke.

I The relative movement of crank shaft 24 with respect to crank 49 maybe varied in this modification by varying the eccentricity of intermediate,shaft'43 with respect to both shaft 50 and crank shaft24 by rotating plate 45. ,Further adjustment of the crank shaft different compressors may be obtained by varying the positions of the cranks on their splined shafts relative to each other. 7

Thus it will be seen that my invention provides means whereby a constant driving speed may be transformedinto a variable piston speed and hence a slow compression stroke may be employed with the result that more time is allowed forheat to be-transmittedfrom the gases during compression through the cylinder walls to the cooling medium. This heat transmission is further in creased by the additional surface presented by water jacket 15a. The increased rate of cooling in turn increases the thermodynamic efficiency and hence a less powerful motor may be employed.

The apparatus constituting my invention maybe used for creating a vacuum as well as compressing a gas. In this event the cranks on the splined shafts would be so adjusted that the downward or suction stroke would take longer than the upward or discharge stroke, as when being used to create a vacuum the suction stroke is the working stroke while the discharge is the return stroke. On the other hand, when being used as a compressor the discharge is the working stroke. In either case the working stroke is comparatively slow and the return stroke fast.

WVhileI have shown and described more or less specific embodiments of my invention it is to be understood that modifications thereof fall within its scope which is to be limited only by the appended claims viewed in the light of prior art.

' What I claim is:

1. In a device for displacing fluid, the combination of a cylinder, a piston in said cylinder. a shaft member, a connecting rod connected to said piston and to said shaft member and means for producing varying speed of said shaft member comprising a second shaft member out of alignment with the first mentionec shaft member, a link eccentrically and. pivotally mounted on both the shaft members, means for rotating the second shaft member at constant speed and means for adjusting the relation of speed of the shaft members.

2; In a device for displacing fluid, the combination of a cylinder, a piston in said cylinder, a shaft member, a connecting rodconnected to said piston and to said shaft member and means for producing varying speed of said shaft member comprising a second shaft member out-of alignment with the first mentioned shaft member, a link eccentrically and pivotally mounted on both the shaft members, means for rotating the second shaft member at constant speed and means for varying the relative alignment of the shafts.

, second link 3. In a device for displacing fluid, the combination of a cylinder, a piston in said cylinder, a crank shaft, a connecting rod connected to said piston and to said crank shaftof'ali 'nment with said intermediate shaft a second link eceentricallv and pivotally mounted on both the driving and intermediate shafts, and means for rotating the driving shaft at a constant speed.

4. In a device for displacing fluid, the combination of a cylinder, a piston in said cylinder, a crank shaft,a connecting rod connected to said piston and to said crank shaft and means for producing varying speed of said crank shaft comprising an intermediate shaft out of alignment with said crank shaft, a link eccentrically and pivotally mounted on both the aforesaid shafts, a driving shaft out of alignment with said intermediate shaft. a eccentrically and pivotally mounted on both the driving and intermediate shafts, means for rotating the driving shaft at a constant speed and means for adjusting the relation of speed of said shafts.

5. In a device for displacing fluid, the combination of a cylinder, a piston in said cylinder, a crank shaft, a connecting rod connected to said piston and to said crank shaft and means for producing varying speed of said crank shaft comprising an intermediate shaft out of alignment with said crank shaft, a linkeccentrically and pivotally mounted on both the aforesaid shafts, a driving shaft out of alignment with said. intermediate shaft, a second link eccentrically and pivotallv mounted on both the driving and intermediate shafts, means for rotating the driving shaft at a constant speed and means for varying the alignment. of said intermediate shaft with respect to one of the other shafts.

6. In a device for displacing fluid, the combination. of a cylinder, apiston in said cylinder, a crank shaft, a connecting rod connected to said piston and to said crank shaft and means for producing varying speed of said crank shaft comprisingan intermediate shaft out of alignment with said crank shaft, a link eccentrically and pivotally mounted on both the aforesaid shafts. a driving shaft out of alignment with said intermediate shaft. a second link eccentrically and pivotally mounted'on both the drivinpandintermediate shafts. means for rotating the driving shaft at a constant speed and means for vary ing the alignmentof said intermediate sha with respect to said crank shaft and said driving shaft.

In testimony whereof I hereunto ar'fix my signature.

VIRGIL WILLIS MORAY.

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