US2198722A - Pump - Google Patents

Description

April 30, 1940. A. G, HORVATH PUMP Filed Nov. '17, 1936 3' Sheets-Sheet 1 Fay. 2

III

INVENTQR Anthony G. )Zorvaih BY 0&1 W

ATTORNEYS 5 P 6 7 0 a. 3 W; 3 M 2 .0 5 H SW L A 7 \i 5 a 3 w m 3 2 z z 6 6 3 I W 2 7 \WQ; 7v 5 6 2 2 Patented Apr. 30, 1940 PATENT osricE PUMP Anthony G. Horvath; Dayton, Ohio, assignor to The Dayton Pump & Mfg. 00., Dayton, Ohio,

a corporation of Ohio Application November 17, 1936, Serial N o. 111,265

6 Claims.

This invention relates to a variable delivery pump.

3 Itis an object of this invention to provide a constant speed variable delivery pump.

5 It is a further object of this invention to provide a pump wherein the capacity is varied directly by the pressure in the tank and. indirect 1y by the quantity of fluid in the tank.

It is a further object of this invention to prog vide such a pump wherein starting and stopping is reduced to a minimum and wherein there is a constant pressure on the delivery end of the pump irrespective of the variation in the quantity of fluid supplied by the pump.

5 It. is a further object of this. invention to provide by-pass means between the pressure chamher and the air chamber. It isaiurther object of this invention to provide such by-pass means as will connect the air chamber and one of thepressure chambers of a double acting pump having two chambers.

It is a further objectof this invention to provide such by-pass means as will connect the air chamber with one of. the pressure chambers of 5 the double acting pump having two such chambers and to provide pressure responsive means between the air chamber and the other pressure chamber which will vary the capacity of the air chamber during the operation of the pump.

, Itis a further. object of this invention to pr-v vide such means which will vary the fluid delivery inversely with the delivery pressure.

It is a further object of this invention to pre vide pressure responsive means between the air i chamber and both pressurechambers in order to vary the capacity of the air chamber of a double acting pump having two pressure chambers.

It is a further object of this invention to provide such means which will periodically vary the capacity of the pump, which means is responsive to the pressure difierential between the air chamber pressure and the respective pressure chamber pressures in order to vary the fluid delivery of the pump inversely with the delivery pressure.

; It is a further object to provide means whereby a part of the fluid from a pressure chamber to the air chamber is by-passed to the other pressure chamber and the return of this bypassed fluid is controlled or varied according to the amount of air pressure in the air chamber whereby, when the pressure in the air chamber is decreased, the amount of this by-passed fluid is decreased and vice versa.

It is a further object of this invention to provide means for varyingthe capacity of the air showing the parts in another position; and

eration of various pump systems throttled todechamber directly with the pressure at the pump delivery whereby the quantity of fluid delivered by the pump will be varied inversely with the pressure at the pump delivery.

It is a further object of this invention to provide a pump wherein the amount of fluid returned from the air chamber to the pressure chamber on the suction stroke varies according to the pressure in the tank.

It is a further object of this invention to pro vide a pump adapted for constant operation during delivery with a minimum of starting and stopping and with a wide range of supply without starting or stopping and a high gallonage of delivery per hour per hOrsepower.

It is a further object of this invention to pro vide an aircushion, a combined air and water cushion and means of relieving the fluid pressure delivery and the starting and stopping oper ations with a consequent saving on the pump and motor. V

. These and otheradvantages will appear from the following description taken in connection with the drawings.

In the drawings: v

Figure 1 is a side elevational View, partly broken away, of a pump according to my invention;

Figure 2 is an end elevational view of the pump shown in Figure 1; 39

Figure 3 is a fragmentary sectional view of the structure shown in Figure 1, with the parts in one position;

Figure. 4 is asimilar view with the parts in another position; Figure 5 is a plan sectional view taken along the line 5-5. of Figure 4;

Figure dis a sectional view of the air chamber of the pump showing the attached pressure switch partly in section; i

Figure 7 is a fragmentary sectional view similar to Figure 3, but showing a modified form of my invention;

Figure 8 is a view similar to .Figure 7, but showing the parts in another position;

Figure 9 is a fragmentary sectional view similar to Figures 3 and 7, but of a second modified form of my invention;

Figure 10 is a view similar to Figure 9, but

Figure 11 is a diagrammatic view showing at (a) the relative discharge of two faucets with various pump systems, in one of which this invention is incorporated, at (b) showing the opliver 210 gallons per hour, in graphic form, and at (0) showing, in graphic form, the operating characteristics of the pump of my invention with relation to pump capacity in gallons per minute and tank pressure in pounds per square inch, wherein the pressure switch is so regulated as to stop operation of the pump when the tank pressure reaches 45 pounds per square inch and to again start the pump when the tank pressure has been reduced to 25 pounds per square inch.

Referring to the drawings in detail, and in particular to Figures 1 and 2, I designates a pump sub-base upon which is secured a pump casting 2, in which is integrally formed at one end thereof crankcase 3, motor platform 4 and crosshead guide cylinder 5. At the other end of the casting, integrally formed therein, is a suction inlet chamber 6 having a pair of intermediate chambers I and la disposed at opposite sides thereof.

Provision is made for the attachment of suction inlet. 8 at one side of the suction chamber 6. The suction inlet is also attached to a primer vacuum chamber 9 which is equipped with suitable interior suction strainer screen (not shown) and at the top with a priming plug I9 and at the bottom with a clean-out plug I I.

Suitable bearings are provided in the crankcase portion of the casting 2 for support of crankshaft !2 which is operatively connected by means of connecting rod I3 to the crosshead M- which is mounted for reciprocation in the crosshead guide cylinder 5. Disposed on the motor platform 4 is a motor I5 or other suitable prime mover I5, which is operatively connected to the pulley it which is rigidly attached at one end of the crankshaft I2. By this means the crosshead M is caused to reciprocate in the crosshead guide cylinder 5 during operation of the prime mover, Attached at one end to the crosshead I4 and disposed axially thereof is the piston rod 11, which passes through a fluid deflector H8 at the end of the crosshead guide cylinder 5, which deflector prevents the entry of fluid on the piston rod IT into the crosshead guidecylinder 5 and thence to the crankcase. Extending across the suction chamber 6 is an open ended cylinder 20 which has its opposite ends opening into the re-. spective intermediatev chambers I and Ia. A stuffing box 2| is threadedly attached to the outer wall of the intermediate chamber 1 and the piston rod I1 which is axially disposed with respect to the stufling box 2| and the cylinder 20 extends through the stuffing box and has the piston assembly 22, which is adapted to reciprocate in the cylinder 20, attached to the threaded end thereof. The casting 2 terminates above the suction chamber 6 and intermediate chambers 1 and la in a flat wall, to which is attached the casting 23 forming the pressure chamber as a whole, which is divided into two parts or pressure chambers 25 and 25a respectively by the dividing wall 24. The pressure chamber 25 is connected by means of port 26 with the intermediate chamber 1 and the pressure chamber 25a is connected by means of port 26a .With intermediate chamber Ia. Apiston plug 28 equipped with a Schrader valve.2I-and of a diameter suitable to provide easy access to the cylinder and of suction valve assembly 29a with the suction chamber 6. The casting 23 has a top wall upon motor I5 and which responds to pressure in the air chamber to stop and start the motor I5 in a known manner. The interior of the air chamber 30 is equipped with a horizontal wall 36 having a constricted port 3! therein. The air chamber 30 is connected to the pressure chamber 25 by means of discharge valve assembly 39. The air chamber 30 is connected to the pressure chamber 250. by means of discharge valve assembly 39a and by-pass orifice 38a.

The valve assemblies 29, 29a, 39 and 3911 are identical comprising apertured plates cooperating with resilient valve plate members resiliently urged thereagainst by means of springs, the resilient valve plates being guided by vertical posts attached at one end to the apertured plates and having the upper headed end thereof adapted for abutment with the upper end of the spring which has its lower end in contact with the resilient valve plate. Suitable gaskets are provided be tween. the air chamber and the casting 23 and betweenthe casting 23 and the casting 2 as well as between the stufling box 2I and the latter casting and between the piston plug 28 and the latter casting so that the escape of fluid at all joints is effectively prevented.

The suction chamber is connected through the primer vacuum chamber 9 to a source of fluid supply and fluid is pumped from the suction chamber 6 through the suction-valves 29 and 29a to the pressure chambers 25 and 25a and thence through orifice 38a and discharge valves 39 and 39a to the air chamber 30 and thence through outlet 32 to asuitable tank or, if desired, directly to the fluid system. While an electric motor is shown and described as the prime mover, it is, of course, to be understood that the principles of my invention may be practiced by the use of other desired prime movers and that the principles thereof may be incorporated in pumps of other constructions than that shown and described, the constructionsiof which may vary widely and it is, therefore. to be understood that the description and illustration of the particular pump is made for purpose of illustration only and is in no wise to be considered as limiting.

Operation With reference particularly to Figures 3, 4 and 5, illustrating the first embodiment of my invention, it will be seen that fluid enters the suction chamber 6 from the suction inlet 8 and from thence the path of the fluid isas follows: when the piston is moving toward the left in the cylinder 20, as shown by the arrow in Figure 3, compression is placed upon the fluid in intermediate chamber 1 and it travels thence through pressure chamber 25 and through discharge valve 39 which is opened by the fluid into the air chamber 3!], whence the main part of the fluid is dis charged through outlet 32, a part thereof passing through the by-pass orifice 38a tothe chamber 2511 which is then under suction. The amount of this fluid passing through by-pass orifice 38a varies directly with the difference in pressure between the air chamber 311 and the chamber 25a.

Simultaneously, fluid is drawn into chamber 25a throughsuction valve 29c because of the suction inintermediate chamber 'la caused by the 1eitward movement of the piston in the cylinder 20.

in chamber la and in pressure chamber 25 and the fluid flowsfrorn chamber 25a into the air chamber 38 through valve 39a andalsothrough the by-pass orifice 38a. The by-pass orifice, on

this strokeof the pump, thus aids the valve 39a. l Thepressure in the air chamber 30 is equal to the pressure in the tank to which the outlet 32 is connected. The pressure switch 34 is responsive to this pressure. As will be clear from the abovedescription of the operation, the difference between the pressure in the air chamber 30 and the pressure in the chamber 25a, during leftward travel of the piston in cylinder 2!],de-

termines how much fluid will be returnedfrom the air chamber 30 through the by-pass orifice 38a during operation of the pump. Thus, when the pressure in the air chamber 30 is relatively low, the proportion of the fluid pumped from a pressure chamber to the air chamber on a particular leftward piston stroke will be greater than when the pressure is relatively higher. The

effectiveness of the by-pass orifice to reduce the rate of delivery varies, therefore,,directly with the pressure in the air chamber 30. Thus it will be seen that, when a relatively large quantity of fluid is being drawn from the tank, the pressure in the air chamber will becorrespondingly reduced and a relatively greater proportion of the total fluid pumped per stroke from the pressure chamber to the air chamber will flow out through the delivery outlet 32. Likewise, when a relativelysmall quantity of fluid is being drawn from a system, the reduction in pressure in the air chamber will be correspondingly less and a correspondingly smaller proportion of the fluid pumped per piston stroke from the pressure charn hers to the air chamber will flow through the outlet 32.

As shown at (a) in Figure 11, the flow between two faucets in a comparison of various systems shows that a 300 to ZOO-gallon per hour pump of variable capacity, due to theapplication of this invention thereto, will deliver 150 gallons per hour to each of the two faucets-while a 25il-gallon per hour pump, in which the practice of this invention is not followed, will pump only 120 gallons per hour to each of the two faucets, and further a 350-gallon per hour pump, which is not equipped for the practice of this invention, will deliver only 165 gallons per hour to each of thetWo faucets, which amounts to a mere fifteen gallons per hour more of capacity per faucet over the capacity of the smaller 300 to 200-gallon per hour pump, variable capacity, as equipped according to this invention. It will thusbe clear that the capacity of the pumps is materially increased by the application of the principles of this invention thereto.

As shown at (h) in Figure 11, wherein the operation ofthe various pump systems, each throttled to deliver 210 gallons per hour at the service faucet, is graphically represented, a 250-gal1on per hour pump starts and stops seven1 times per hour and in each of these cycles runs for seven minutes and stops for one minute, while a 300 to200-gal1on per hour variablecapacity pump,

, above described by-pass orifice 38a.

in which are incorporated the principles ofthis invention, delivers a steady stream offluid at constant pressure. would start and stop twenty times per hour and in each cycle would run for two minutes and stop forone minute.

At is illustrated the'operating character istics of a variable capacity pump of 300 to 200 gallons per hour capacity; in which is incorporated thisinvention. It will be noted that, when the tank pressure is zero, the capacity is 350 gallons perhour, that when the tank pressure is ten pounds per square inch, the capacity is 300 gallons per hour, that when it is twentyflve pounds per square inch, the capacity is 260 A 350-gallon per hour pump,

gallons per hour and that when the tankpressure is forty-five pounds per square inch, the capacity is 210 gallons per hour, and that when the tank pressure in pounds per square inch is fifty, thecapacity of the pump is 200 gallons per hour. As indicated in the graph in dotted lines, the pressure switch is preferably so adjusted that, when the pressure in the tank drops to twenty-five pounds per square inch, the pump will be started and will continue to run until the tank pressure reaches forty-five pounds per square inch,'when the switch will shut off the pump.

It will thus clearly appear that, besidesproducing a variable capacity in a constant speed pump, I have produced a new method of operation, by which the starting and stopping of the pump is reduced to the minimum which amounts to a great saving in power consumed andin wear j whereby a smallerpump maybe used for a predetermined load than has hitherto been possible and likewise a more economical operation may be achieved due to the fact that a smaller prime mover will be necessary than otherwise. v

In Figures 7 and 8, I have illustrated a modified form of my invention, in which the structure is similarto that of the modificationdisclosedin Figures 1 to 5 inclusive, save, that in addition to the bypass orifice 380., which is interposed between the air chamber 35'2 and the pressure cham-- ber a, Ihave utilized a diaphragm mechanism, generally designated 49, which is interposed between the airchamber and the pressure chamber 25 for the purpose of modifying the efi'cct of the Thediaphragm mechanism, as disclosed, comprises an externally threaded cylindrical body portion M which is threaded into the top wall casting 23 to communicate with boththe pressure chamber 25 and the air chamber 39. At each end of the bodyportion 4i isattac hed a cap member 42 which is provided at its inner side with a guide adapted to engage and support one end of a coil spring. The cap members 42 are or upper spring, is designated a;

body member 4|. Between each of these cup washers 43 and the adjacent. cap 42 is interposed a compression spring.

spring 45 and is normally overbalanced by the lower spring 45, as shown in Figure '7. The'cup washers and disk 44 are thus retained in the position shown in Figure 7 when the chamber 25 is under pressure and also when'the difference in pressure betweenthe air chamber 3i! and the pressure chamber 25'isequal to, or less than, the, difference in strength. between'the springs 45a and 45. In other words, whenever the sum of the fluid pressure and the spring pressure on the top cup washer 43 is less than or equal to the sum of the fluid pressure and the spring pressure on the lower cup washer 43', the parts remain in the position shown in Figure 7, whereby the effective volume or capacity of the chamber 3!] is unchanged by the diaphragm 40.

The upper springs 45a are, in effect, merely shock absorbers and other means, such as a rubber stop or the like, may be substituted therefor. It will thus be seen that the springs 45a and 45 may be so balanced that the diaphragm will not act to increase the effective volume or capacity of the chamber 39 until a predetermined pres-- sure is produced in the system (and in the air chamber (it, which is connected thereto). Other adjustments are, of course, comprehended by me in the practice of the principles of my invention.

As'shown'in Figure '7, when the pump piston is traveling to the left and the parts are in the position therein shown, fluid passes through the valve assembly 39 from the pressure chamber 25 to the air chamber 30, while a. portion thereof, varying directly with 'the difference in pressure between the chambers 30 and 25, and varying directly with the pressure in the system and in the chamber 39, will pass through the bypass orifice 38a from the chamber 30 to the chamber 25a. During this stroke, the capacities of the chambers are unmodified by the diaphragm 40.

As shown in Figure 8, in which the difference in pressure between the air chamber'30 and the pressure chamber 25 is taken asgreat enough to cause compression of spring 45, and in which the parts are in the position shown in Figure 4 and the piston is traveling to the right, the pressure chamber 25a is under compression, while the pressure chamber 25 is under suction. Fluid flows from the pressure chamber 25a through valve assembly 280i and through by-pass orifice 38a to the air chamber 30. The cup washers of the diaphragm 40 are depressed against pressure of the spring 45, wherebythe volume of the air chamber 3llis increased and the volume of the pressure chamber 25 is decreased. Considered in another way, the diaphragm. has then temporarily increased the pressure in the pressure chamber 25 and has decreased the pressure in the air chamber 30. I

When desired, Iumay omit the orifice 38a between the air chamber 30 and the pressure chamber 25a, in which case the effect of the diaphragm 40 will be to increase the capacity or volume of the air chamber 30, when the pressure chamber 25 is under suction, while at the same time decreasing the amount of fluid entering the chamber 25 due to the temporary decrease in the permanent effective volume thereof. Likewise, when the chamber 25 is under pressure, the diaphragm 40 will be ineffective to modify the capacities of the respective chambers.-

Likewise, when desired I use, in addition to the diaphragm interposed between the airchamber 3d and the pressure chamber 25, a similar diaphragm 40a similarly disposed between the'air chamber 30 and the pressure chamber 25a,-as shown in Figures 9 and 10. As shown diagrame matically in these figures, when the parts are in the position illustrated in Figure 9, and the pump piston is traveling to the left, the diaphragm 40 will be ineffective to decrease the pressure in the chamber 25,.which is then under pressure, or to decrease the pressure in the air chamber 30, while the diaphragm the is simultaneously decreasing the pressure in the chamber 30 by increasing the effective volume or displacement that the functions of the respective diaphragms 4t! and Mia are, in that case, reversed.

As explained above, in the description of the embodiment disclosed in Figures '7 and 8, as the mean effective pressure in the air chamber 30 increases upon increase of pressure in the pump system, the mean effective volume, displacement or capacity of the chambers 25 and 25a decreases. Thus, the mean effective capacities or volumes of the chambers 25 and 25a vary inversely with the mean effective pressure in the air chamber 30. As the spring 45 of each diaphragm follows Hookes law, the compression thereof will vary directly as the pressure in. the air chamber 30 because the spring overbalancing pressure will vary directly therewith;

As will be clearly understood, the effects of the orifice 38a and diaphragm 40 in the embodiment illustrated in Figure '7 will be-dependent upon the pressure differential between the air chamber 30 and the respective pressure chambers 25 and 25a. The particular characteristics of the pump operation are further dependent upon the sensitivity or strength of the opposed springs 45 and 45a in the diaphragm. Likewise, the strengths of the opposed springs 45 and 45a may be varied to secure further modification of the operating characteristics of the pump. In any event, both in the embodiment disclosed in Figures '7 and 8 and in the modification thereof (which, though not illustrated, has been described as being similar to that disclosed in Figures '7 and 8, save that the orifice 38a has been omitted), the pressure differential between the air chamber 30 and the chamber 25 will be decreased by the diaphragm 40 when the pressure differential exceeds a predetermined value. Thus, when the pressure in the air chamber 30 is: increased, the amount of fluid passing into this chamber from the chamber 25 is decreased.

Likewise, in the embodiment illustrated in Figures 9 and 10, the pressure differential between the air chamberflfi and both pressure chambers 25 and 25a will be decreased by the diaphragms. 40 and 40a by an amount which will vary directly with the pressure in the air chamber. The amount of fluid passing into the air chamber on each reciprocation of the pump piston will likewise be lessened by an amount varying directly with the pressurein the air chamber 30.

in each of the embodiments described, the de' liveryoffthe pump will vary inversely with the 1 pressure in the air chamber 30. "The pressure 1 in the air chamber iil) beingiclentical with the delivery chamber ortank pressure of the pump, the; delivery rate of the pump will, therefore, vary inversely witht'he delivery. pressure of the pump. i -1 WhileI have illustrated only one form of diaphragmitis, of course; to be understood that various other types of diaphragms may be used .for the same purpose. Likewise, if it is desiredto unbalance the deliveries of fluid from the re spective chambers 25. and '25s, this may be acjcomp-lished by suitable variation of the spring pressures on the respective diaphragms dllfand lisa, by variation of the size of the by-pass orifice K fiua and/or the use of more than onediaphragm where one haslbee'n illustrated and/or the use of pdiaphragms of difierentsizes and/orcharacteristics. For instance, in the embodiment illustrated in Figures 9 and 10,two diaphragms may be substituted for one of the diaphragmsw there shown. The same result might be accomplished the substitution for one of the diaphragms shownof a diaphragm having greater cross sectional area. Likewise, the connection of, the dia- I phragm between the air chamberand one of the means and bysuitable associated valves these j diaphragmsmay be made selectively operable.

pressure chambers may be made throughexterior When, a pump constructed according to the principles of my invention is applied to a fluid r pressure system including an air pressure tank,

1 withdrawal of fluid from the system causes entry of air into thegtank. Afterthe entry of air into thetank, the air intake valve remains closed. vIf .unequipped according to theprinciplesoi my in- .ventiornthe pump would tend to deliver, its full capacity; until the pressure in the tank and inthe .crease of pressure in the system wherebyto prevent undue starting and stopping of themotor and unduewear upon the pump and upon the motor. This is due to thegprovision of the bysystem were raised sufliciently tocause the pres sure switch l-A to shut down the motor. How ever, due to the incorporation in the pump; of the 1 principles of my invention, the delivery of the.

pump will be progressively decreased with inpass oriflcer38a, in the embodimentdisciosed in Figures 1 to 6. inclusive, to the'provision of the diaphragm 40 and by-pass orifice 38min the embodiment illustrated in Figures 7 andS, to the ,1 provision of the diaphragm 40 alone with theby pass orifice 38a eliminatedin the above described unillustrated modification, and to the provisionof both diaphragms 41! and 40a in the embodiment illustrated in Figures 9. and 10.

513:; the provision of these meanspthe pump is given a capacity which variesinversely with re- .spect to the pressure of theesystem, because of Ithe above described lessening of the intake in the pressure chambers 25 and 25a and/or the return from the air chamber 38 of a quantity of fluid through the bypass orifice 38a (when utilized) which quantity varies directly with the pressure in the system. The incorporation of the i above described features in i a pump permits greater increase of displacement without loss of prime than is otherwise possible. i

It will be understoodtthat the above described structure is merely illustrative ofthe manner in which my invention maybe carried out and that I desire to comprehend within my invention such sage of predetermined size between said air chamher and said pumping chamber for automatically varyingthe delivery of the" pump inversely with the pressurein said air chamber.

2. In a pump having an air chamber and a pumping chamber adapted to supply fluid thereto,

the pressure in said airchamber comprising fixed 25 means for varying the delivery inversely with by-pass means connecting said air chamber to said pumping chamber internally of the pump.

3. Ina pumpjhavingran air chamber and 'a pumping chamber adapted to supply fluid thereto, means disposed interiorly of the pump for by- .passing from said air chamber to said pumping chamber aportion of said fluid directly proportional to the pressure in said air chamber.

4. In a constant speed pump having, an air chamber and a pumping chamber adapted to supply fluid thereto, means responsive to the pressure in said air chamber for varyingthe delivery of said pump atconstant speed by returning from said air chamber to said pumpingchamher a portion of the pressure insaid air chamber.

5. In a constant speed. pump; having an air chamber and a pair of pumping chambers adapted to supply fluid thereto, one of said chambers having. air intake means, means for controlling the delivery of said pump by returningfrom the air chamber tethe pumping chamberhaving air intake means, a portion of said fluidvarying di rectly with the pressure in said air chamber. i

6. In a pump having an .air chamber, a pumping chamber adapted to supply fluid thereto, and

, valve means adapted to provide communication v between said pumping chamber and said air chamber in one direction, means-for varyingthe delivery of saidpump in inverse ratio to the pressaid fluid varying directly with sure in said air chamber, comprising by-pass meansdisposedinterinrly of said pump and connecting said pressure chamber and said air chamber.

i ANTHONY; G. HORVA'I'H.

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