US2751847A - Fuel pump - Google Patents

Description

June 26, 1956 R. w. ERlKsoN FUEL PUMP 2 Sheets-Shea?I 1 Filed Feb. 28, 1952 June 26, 1956 R. w. ERlKsoN FUEL PUMP 2 Sheets-Sheet 2 Filed Feb. 28, 1952 INVENTR. veri ZZ/.Zrsom United States Patent .i

FUEL PUMP Roberty W. Erikson, Rockford, El., assigner to Sandstrand Machine Tool Co., a corporation. otvlliinois,

Application February 28, 1952, Serial No. 273,810

8 Claims. (Cl. 10342) This invention relates to a pump and-'more particularly to a pump adapted for use with 'anV oil; burner for supply;` ing fuel oil under pressure to the nozzle of the burner.

It: isV thel general object ofV this, invention to produce a new and improved oil burner pump.

lt is a more specific object of the invention to producel an oil burner pump provided with burner shutof valve means for controlling the ow of oil from the pump to the burner and so constructed and arranged as to reduce pulsations and uctuations to a minimum.

Another object of the invention is to produce an oil burner pump of the type described in the preceding paragraph having means for adjusting the valve to open at various predetermined pressures which is easily operable andf which. is constructed to operate over a comparatively wide range of pressures.

A further object of the invention is to produce" a two-VY stagc oil burner pump in which a first-stage pumping means is used to draw oil from a supply tank'to a reservoir and a second-stage pumping means is used to pumpoil from the reservoir to the burner and in which there is provided a burner cuto' valve having bypass means for bypassing excess oil moved by the second-stage pumping means backV to the reservoir, with the valve being designed. so as to be easily adjustable to open at various pressures without being inliuenced by pressure conditions. within the reservoir.

Yet another object of the invention is: to produce a pump of the type described in the preceding paragraph in whichV the valve includes a bore having a piston valve slidable therein to divide the bore into a valve chamber, having a burner port controlled by the closed; end ofl the pistou valve, and a spring chamber in which there is located a spring for urging the valve toward closed position, together with sealing rings for preventingoil in the valve chamber or oil flowing through. the bypass means from entering the spring chamber.

Av further object of the invention. is to produce a pump. of the type described in. the preceding paragraph which includes a drain port for draining oil which. may leak past the sealing means and intoV the spring chamber.

Yet. another object of the invention is to produce a pump as described in the preceding paragraphs in which the first-stage pumping means is provided with an, inlet opening, into the reservoir at the normal level of liquid therein .so as to draw oil' into the reservoir from a supply andv to draw from the reservoirl excess oil andi air, and in'wlich the discharge of the hist-stage pumpingmeans may be connected to the spring chamberof the Valve robe drained' therefrom through the drain port.

Other .and furtherV objects of' the invention will be readily apparent from theV following description and drawings, in which:

Eig.Y l is a longitudinal'v central section' through a preferred form of. the invention;

V ,lig. 2 is a sect-ion approximately along' l'ineof 'Fig'. l; and

Fig. 3 is a diagrammatic view of the fuel circuit.

2,751,847 Patented .lune 26, 1956A While thisA invention is susceptible of embodiment in many dierent forms, there is shown in the drawings and will herein be described in detail one specic embodiment, with the understanding that the present disclosure is to be considered as an exemplication of the principles of the invention and-is not intended to limit the invention to the embodiment illustrated. The scope of the inven= tonwill beponted out in the appended claims.

ln the form chosen for the purposes of disclosure, the pump may comprise a two-part casing 10, 11, a rs't pumping device or means 12, a second pumping device or means 13, a drive shaft 14, a mechanical seal v for the drive shafua strainer 16 and a control valvernecla-A nism 17a lt isV contemplated that the shaft 14 willv be connected by suitable means to a driving motor (not shown) thatV the inlet port 18 vvill be connected to a source of fluid supply and the discharge port 19ito' a' burner nozz'le. The casing parts are formed to provide a substantially cylindrical chamber in which. the pumping devices 12" and 13 and strainer 16 'are positioned and including a reservoir 20 to which the pumping devices. are connected for the purposes hereinafter more fully de; scribed.

As illustrated herein the casing part 10. is in the form ot' a body member which is alsoused for supporting the fuel unit. Preferably this member is formed withA sup porting lugs 21V having bolt receiving apertureszz. The part 11- is inthe form ci a closure' or cover andiis.4 bolted to the part it) by the means of` a plurality of screw d= vices 23;

The pumping devices l2 and 13 include endr plates 24 and Z5', an intermediate plate 26 and. annular spacing members 27 and 2S. The first-stage pump 12 comprises rolier or pinion 29 and an interrneshing toothed ring 3tlwhich `are operable inthe chamber formedl intermediate the plates 24 and 26. The second-stage pump' 13 comprises a roller or pinion 31 and a toothed ring 32 operable in the chamber forx'nedy intermediate the plates 26y and 25. The rollers 29 and 31 are providedv with driving pins 33 and 34 respectively which interengage With a keyway 35 in the drive shaft 14 when the pumping unit isassembled. A crescent 36 for the rstl-stage pump is secured to the' plate 24! and a crescent 37 is secured to the intermediate plate 26 fori the' second-stage pump.

Anv inlet port 40' is drilled in the end plate` 24V and cxtendsthrough the periphery of the plate forv supplying uid to the rs't-st'age pump. The intermediate plate 26 has an arcuate discharge cavity 42 which is connected with a channel port 43 formed in the plates 26, 28 and 25. Oil in the channel port 43' is directed into ai chamber 44 by passage 44a which extends through the member 101 into achamber 4419 at the location of the seal 15 and thence into a passage 411e which connects with an annular recess `45' which is joined by a` diagonally drilled hole 5a to a return port 46. The second-stage pump is. provided withfluid from' the bottom of the reservoir 20 through an inlet porti formed in the plate 26. Fluid from the second-stage pump passes through' an outlet port SI which communicates with' a va'lve chamber' 52.

I'n' the form of thel invention illustrated herein; th'e casing part IG has an appendageY portion 60 provided' with a'transv'er'sely extending' bore 61. Theva'lveehar'nberSZ is formed iny this bore between the` adjacent-end ofC an end cap 62 which is crew-threaded into one endy of' the bore and a sleeve member 63' which is inserted into the central portion of the bore. If desired, a suitable gauge port- 64 connected tothe valve chamber 52 by passage daar may be provided.

A- hollow' piston valve 65 is slidably mounted in the sier-ive. 63 so that the closed end 66 thereof Will be subi jecte'dito' the uid' pressure in the valve chamber 52.V 'I'li' piston valve 65 is provided with substantially cylindrical side walls 67 and is open at 1ts end opposite the end 66 to divide the bore 61 into the valve chamber 52 and a spring chamber 68. A coiled spring 69 bears at one end against the inner side of the bottom 66 of the piston and at the other end against a thrust washer 70 which in turn bears against an adjusting screw 71 screw-threaded into an end cap 72 which closes that end of the bore. A cap member 73 is provided with internal threads engaging the threads on a boss portion 74 integrally formed on the end cap 72, and a sealing ring 75 is adapted to be compressed between the cap 73 and the end cap 72 to seal ott' the spring chamber 68 from the atmosphere. Adjustment of the spring 69, of course, determines the pressure at which thevalve opens.

Bypass means are provided for bypassing excess uid' moved by the second-stage pumping means 13. To provide such bypass, the piston valve 65 is arranged to uncover a bypass port 76 which is formed in the sleeve V63 and communicates with an annular vrecess 77 formed around the sleeve 63. This annular passage communicates with a bypass passage 78 which leads back to the reservoir. 20. Formed in the portion of the sleeve 63 *adjacent the valve Ychamber 52 is a plurality of passages 80 extending generally longitudinally of the sleeve, with each ofrthe passages 80 being open at one end to the valve chamber 52 and at the other end to the interior surface of the sleeve at a point spaced inwardly from the end'thereof. vAn annular groove 81 is formed on the exterior surface, of the side walls of the piston valve 65 and is adapted to establish communication between the passagesj80 and the bypass port 76 in the sleeve when the'valve is opened by uid pressure within the valve chamber. YThe degree of registry between the groove 81 and the port 76 depends, of course, upon the amount of movement of the piston valve l65 and hence the oil is variably bypassed depending upon movement of the piston valve which in turn depends upon the pressure of Vuid within the valve chamber 52 and the setting of the spring 69. Bypassed excess tluid entering the bypass port 76 passes into the annular groove 77 and into a bypass port 82 which communicates with the bypass passageV 78 to return such excess oil to the reservoir.

It will be noted from an examination of Fig. 3 that the inlet .'40 of the first-stage pump 12 is connected to the reservoir 20 near the upper portion thereof. The location otl the inlet port 40 is at the normal oil level, indicated at 90,V within the reservoir and thus the first-stage pump serves, in the iirst instance to draw oil into the reservoir from the inlet 18 and, after the reservoir has lled to the desired level, excess oil Vand air is removed therefrom by the first-stage pump. The inlet of the second-stage pump is .connected to Vthe reservoir below the normal level of liquid therein and thus receives oil by gravity flow to the inlet port 50. This particular arrangement of the inlet ports ofi the first and second-stage pumping means quite eiectnally removes air from the oil before it enters the inlet of the second-stage pump and thus prevents air from beingentrained in the oil ow to the'burner nozzle. A similar system is morelfully described and claimed in the copending application of William Ray Kiefer led 'on Februaryy 16, 1951 as Serial No. 211,244.

Avfurther advantage of the system disclosed hereinY is the factthat excess oil pumped by the second-stage pumping means,` which oil has already been freed from air'by theoperation of the first-stage pumping means, is returned to the reservoir, thus reducing the quantity of oil which must be drawn from the supply by the first-stage pumping means, thereby reducing friction losses in the feed line 'from the source of oil.

The-open endedportion of the piston valve is provided with ajpair of integrally formed rings 91 and 92 which serve to prevent leakage along theV walls of the piston valve and into the'valve chamber 68. Any leakage from the annular groove 81'past another integrally formed ring 93 which separates that annular groove from a second annular groove 94, is led into the annular groove 77 through a drain port 95 for return to the reservoir. T0 prevent leakage from the valve chamber 52 or from the various bypass passages into the spring chamber, a pair of O-rings 96 and 97 are provided between the sleeve 63 and the bore 61. Minute quantities of oil which may leak past the seals just described and into the spring chamber may be drained therefrom through a port 98 formed in the sleeve which connects with the annular groove 45 and thence to the drain line 46.

To eliminate `the number of ports required in the valve` casing and to provide for a constant pressure in the spring chamber, the discharge from the irst-stage pump through the outlet passage 44 is directed into the annular groove 45, to which, as previously noted, the port 98 is connected.

As has previously been indicated, adjustment of the compression of the spring 69 is by means of the adjusting screw 71. Inasmuch as the excess of uid moved by the second-stage pump is directed back into the reservoir, it is clear that if the sealing means previously described were not provided to seal off the spring chamber 68 from the bypass system for the second-stage pumping means, the same vacuum conditions would exist within the spring chamber as exist within the reservoir 20. As the adjusting screw 71 does not provide an'airtight seal, the cap 73 and seal 75 are provided. If the same vacuum conditions existed in the spring chamber as in the reservoir, removal of the cap 73 would disturb such vacuum condition during the adjustment of the screw and removal of cap 73 under such circumstances would actually cause the unit to be inoperative, that is, the ow of oil would cease, if reservoir 20 is under appreciable vac-v uum. Because of the fact that the spring chamberV is sealed from the bypass means, no such di'iculty in adjustment arises. Furthermorq'variations in inlet pressure within the reservoir are likewise sealed from the spring chamber to eliminate variations in valve position because of variations of the pressure in the spring chamber caused thereby. Because of the further fact that the discharge from the rst-stage pumpV is introduced into the spnng chamber, a constant positive pressure exists therein. These features facilitate proper adjustment of the spring tension on the piston valve to fit the requirements of various operating conditions and also provide for stable operation of the valve.

I claim:

l. -An oil burner pump having, in combination, a casing, a pumping means in the casing, a reservoir in the casingto which-the inlet of the pumping means is connected, a bore in the casing closed at one end to forma valve chamber, an inlet port opening to said chamber and connected to the outlet of the pumping means,ran outlet in the boreV leading from said chamber, a piston valve slidable in said bore and controlling the outlet port, saidfvalve having a, closed end subject to the pressure ofthe 'fluid in said valve chamber and urgedthereby toward open position, means ypositioned in the portion 'ofy the bore separated from the valve chamber by the piston valve for biasing said valve towards closed position, and bypass means for the valve including a bypass port open: ing into' said bore at a point remote from the valve chamber, a bypass Vpassage communicating Vat one end with the bypass port and Yat the other end with the reservoir, la passage in the casing constantly open at one end to receive a portion of the uid in the valve chamber and opening at the other end to the bore atv a point spaced inwardly from said valve chamber, passage means in theexterior surface of lthe piston .valve and spaced from the closed end thereof Vand movable with said valve Vrelative to said passage to control ow fromsaid passage to saidbypass port, and sealing means for sealing theA portion of the bore separated from the valve chamber bythe piston lvalve from the liquid in the valve chamber and from` liquid owng throughsaid bypass means in all` operating positions of said piston valve.

2. An oil burner pump having, in combination, a casing, ar pumping means in the casing, a reservoirr in the casingvv to which the inlet of the pumping means is connected, a borein the casing closed at one end to form a valve chamber, an inlet port opening to said chamber and connected to the outlet of the pumping means,.an outlet inthe bore leading from said chamber, a piston. valve slidable in said valve chamber, said valve having a closed end subject to the pressure of the uid in said valve chamber and urged thereby toward. open position, means positioned in the. portion' of the bore separated fromthe valvev chamber lby the piston valve for biasingsaid valve towards closed position, and bypass means for the valve including a bypass port opening into said bore at a point remotefrom the valve chamber, a. passage in the` casing constantly open atone end to receiveaportion of thefluid inthevalve'chamber and opening at the other end to'the bore at a pointspaced inwardly from said valve cham- 'H ber,.passage means in the exterior surface of the piston valve and spaced from the closedend thereof and movable withv said valve relative to` said passage to control flow fromsaidpassage to said bypass port, a bypass passage connecting the bypass port to the reservoir, sealing means for sealing the portion of the bore separated from the valve chamber by the piston valverfrom the liquid in the valve chamber and fromv liquid flowing throughsaid bypassmeans in all operating positionsof said piston valve and a drain port connected to the last mentioned. portion of the bore for draining therefrom uid leaking pastY the sealing, means.

3. An oil burner pump having, in combination, a casing,l a pumping means in the casing, a reservoir in the casing to'which the inlet of the pumping means is conl nected, a cylindrical bore in the casingV closed at one end to formY a valve chamber, an inlet port opening to said cham-ber andV connected to the outlet of the pumping means, an outlet port leading from said chamber, a cylindrical sleeve fixed in the bore, a hollow piston valve slidable in said sleeve and controlling thev outlet port, said valve having a closed end and generally cylindrical side walls to define in said bore a spring chamber separated by the piston valve from. the valve chamber and said valve being movable in response to the pressure in the valve; chamber toward-open position, aV spring in the spring chamber andV contacting the valve to bias the valve toward closed position, and bypass means forA theV valve including a bypass port opening into saidbore at a point remote. fromV the valve chamber, a bypass port in the sleeve'communicating with the bypass port in thefbore, a passage in the sleeve constantly open at one endfto receive a. portion of the uid' in the valve chamber and, opening at the other end" to the interior surface of the sleeve at a point spaced inwardly from said valve chamber, an annular groove in the exterior surface of the piston valve spaced from the closed end thereof and movable with said valve relative to said passage to control flow from said passage to said bypass ports, and sealing means for sealing the spring chamber from the liquid in the valve chamber and from liquid owing through said bypass means.

4. An oil burner pump having, in combination, a casing, a pumping means in the casing, a reservoir in the casing to which the inlet of the pumping means is connected a cylindrical bore in the casing closed at one end to form a valve chamber, an inlet port opening to said chamber and connected to the outlet of the pumping means, an outlet port leading from said chamber, a cylindrical sleeve fixed in the bore, a hollow piston valve slidable in said sleeve and controlling the outlet port, said valve having a closed end and generally cylindrical side walls to define in said bore a spring chamber separated by the piston valve from the valve chamber and said valve being movable in response to the pressure in the valve chamber toward open position, a spring in the spring chamber and contactingtheivalyeto bias the valve toward closed position, bypass means for the. valveincludinga bypass port' opening into said bore at a point remote from the valve. chamber, a bypassport inthe sleeve communicating with the bypass port in the bore,; apassage inthe sleeve constantly open at.one end to receiveaportionof the Huid. in the valve-chamber andopening at the otherend-to. the interior` surface of the sleeve ata point spaced inwardly from said valve chamber, an. annular groove in the exterior surface of the piston valvespaced from the closed end thereofV and movable with.y said, valve relativeto saidpassageto control flow from. said .passage to said bypass ports, and a pair of Oringseals between, tliesleeve and the bore and positioned onopposite sides ofthe bypass ports to. seal.. the spring: chamber from uid passage through said bypass means.

5.V A-n oil burner pump havingfy in combination, a casing, a pumping means in the casing, ay reservoirv in the casing to which. the inletv othe pumping means is connected, a cylindricalbore in the casing. closedl at one end. to form a valve chamber, an4 inlet port: opening to` saidv chamber and connected to they outlet Yof the pumping means, an outlet port leading from said chamber, a cylindrical sleeve fixed in` the bore, a hollow piston valve slidable in said sleeveand controlling the outlet port, said valve havingal closed end., and generally cylindrical side walls to define in.V said bore a spring chamber separated bythe piston valvel from the valvef chamberand; said val-ve beingV movable in response to the pressure in the valve chamber toward open position, a compression spring inthe spring chamber and contactingI the valvev to? bias the valve toward closed position,l means for ad: justin-grthe compression of they spring, mea-ns sealing saidv adjusting,rneansfromv the atmosphere, bypass means4 for. the valve including a bypassport opening. into. said bore at a4 point remote from the valve chamber, a bypass port. in: the sleeve communicating with the bypass. port in the bore, means connectingthe bypass port in lthe bore to the reservoir, sealing means for sealingA theportion of the bore separated from the valve chamber by the piston valve from the liquid in the valve chamber and from. liquidY flowing through said bypass means and a drain port connected to the spring chamber for draining therefrom fluidleaking past' the sealing means.

6. A1 two-stage oil burner pumpk having, in combination, acasing, a rst-stage pumping means inthe casing, a secondi-stage pumping means. in the casing, a reservoir i-nn theV casing to which the inlet of the second-stage pumping means; is connected, a supply tank connection leading to said reservoir, an. inletk connection for the first-*stage pumping means communicating with the reservoir to draw oilk th'ereinto through the supply tank connection, a bore in the casing closed at one end to form a valve chamber, an inlet port opening to said chamberand connected to the outlet of the second-stage pumping means, an outlet in the bore leading from said chamber, a piston valve slidable in said valve chamber, said Valve having a closed end subject to the pressure of the uid in said valve chamber and urged thereby toward open position, means biasing said valve towards closed position, bypass means for the Valve including a bypass port opening into said bore at a point remote from the valve chamber, a passage in the casing constantly open at one end to receive a portion of the uid in the valve chamber and opening at the other end to the bore at a point spaced inwardly from said valve chamber, passage means in the exterior surface of the piston valve and spaced from the closed end thereof and movable with said valve relative to said passage to control ow from said passage to said bypass port, means connecting the bypass port to the reservoir, sealing means for sealing the portion of the bore separated from the valve chamber by the piston valve from the liquid in the valve chamber and from liquid flowing through said bypass means, a port in the last-mentioned portion of the bore connected to the outlet of the first-stage pumping means, .and means providing a drain for said portion'of theV bore to drain therefrom excess uid pumped by the first-stage pumping means and uid leaking'pastthe sealing means.'H

f "7.'Av two-stage oil burner pump having, in combination, Va (casing, a rst-stage pumping means in the casing, asecond-.stage pumping means in the casing, a reservoir in the casingvto which the inlet to the second-stage pumping means is connected below the level at which the oil stands during normal operating conditions, a supply tank connection leading to said reservoir above the normal operating level of the oil therein, an inlet connection for 'the `first-stage pumping means communicating with said reservoir at the normal oil level to enable the first-stage pumping means to withdraw excess oil and any air above said level, a cylindrical bore in the casing closed at one end to form a valve chamber and closed at the other end by cap, an inlet port opening to said chamber and connec'ted to'the outlet of the second-stage pumping means,

an outlet port leading from said chamber, a cylindrical f sleeve fixed in the bore, a hollow piston valve slidable in-said sleeve and controlling the outlet port, said valve having a closed end and generally cylindrical sidewalls to d'eine in said bore a spring chamber separated by the piston valve from the valve chamber and said valve being movable in response to the pressure in the valve chamber toward open position, a compression spring in the spring'chamber and contacting the valve to bias the valve toward closed position, a screw device engaging threads formed vin an opening extending through the cap for adjusting the compression of the spring, a Aseal Vfor sealing the outer end of said opening and removable to permit adjustment of said screw device, bypass means for the valve including a bypass port opening into said borevat a point remote from the valve chamber, a bypass port in the sleeve communicating with the bypass port in the bore, a passage in the sleeve constantly open at onevend to receive a portion of the iluid in the valve chamber and opening at the other end to the interior surface of the sleeve at a point spaced inwardly from said valve chamber, an annular groove in the exterior surface of the pistonY valve-spaced from the closed end thereof and movable with said valve relative to said passage to control iiow from said passage to said bypass ports, a passage connecting the bypass port in the bore to the reservoir, a port inpthe spring chamber connected to the outlet of the rstlstage pumping means, sealing means for sealing the spring chamber from oil owing' through said bypass means, and means providing a drain for said spring chamber to drain therefrom excess fluid pumped by the first-stage -pumping means and uid leaking past the `sealing means.

8. A two-stage oil burner pump having, in combination, a casing, a iirst-stage pumping means in the casing, a second-stage pumping means in the casing, a reservoir in the casing to which the inlet to the second-stage pumping means is connected below the level at whichthe oil stands during normal operating conditions, va supply tank connection leading toV said reservoir above the` normal op# eratinglevel of' the oil therein, an inlet connection' 'for the rststage pumping means communicating with said reservoir at' the normal oil levelto euable'the lirst-s'tage pumping means to withdraw excess oil and any air above said level, a cylindrical bore in the casing closed at one end toform a valve chamber and closed at the otherend by a cap, an inlet port opening to said chamber and connected to-the outlet of the second-stage pumping means', an outlet port leading from said chamber, a cylindrical sleeve iixed in the bore, a hollow piston valve slidable in said sleeve and controlling the outlet port, said valve having a closed end and generally cylindrical side WallsV to define in saidibore a spring chamber separated'by the piston vvalve from the valve chamber and said valve being movable in response to the pressure in the valve'chamber toward openv position, a compression spring in the spring chamber and contacting the valve to bias the valve toward closed position, a screwdevice engaging threads formed in an opening extending through the cap for adjusting the compression of theV spring, a seal rfor sealing the outer end ofY said vopening and removable to permit adjustment of said screw device, bypass means for Athe valve including a bypass port opening into said;boreat a point remote from the valve chamber, a bypass portin the sleeve communicating with the bypass port in the bore, a passage in the sleeve constantly open at one end torre= ceive a portion of the iiuid in the valve chamberand opening at the other end to the interior surface of the sleeve at apoint spaced inwardly from said valve chamber, an annular groove in theexterioresurface of the lpiston valve spaced from the closed end thereof and movable with said valve relative to said passage to control ow from said passage to said bypass ports, a passage connecting the bypass port in the bore with the reservoir, a pair of 0' ring seals between the sleeve and the bore and positioned on opposite sides of the bypass port in the bore to seal the spring chamber from fluid passing through said bypass means, a port inthe spring chamber connected to the outlet of the first-stage pumping means and means providing a drain for said spring chamber to drainv therefrom excess fluid pumped by the first-stage pumping means and uid Aleaking pastthe sealing means. Y

References Cited in the file of this patent .Y

Y UNITED ySTATES PATENTS Murphy Mar. 3 1.9 36

Wahlmark Feb. 2,

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