US2512072A - Fuel pumping unit - Google Patents

Description

June 20, 1950 c. H. RYSTROM 2,512,072

FUEL PUMPING uurr Filed Oct; 25, 1944 3 Sheets-Sheet 1 7M me C. H. RYSTROM FUEL PUMPING UNIT June 20, 1950 Filed Oct. 25, 1944 3 Sheets-Sheet 2 &

flM m M June 20,1950 c. H. RYSTROM 2,512,072

mar. puunmc uurr File d Oct. 25, 1944 :5 Sheets-Sheet a Patented June 20, 1950 UNITED STATES PATENT OFFIE Charles H. Rystrom, Rockford,'Ill. 7 Application October 25, 1944, Serial No 560,326

2 Claims. (Cl. 10342) Myinvention relates generally to fuel pumping units, particularly those of a type suitable for supplying oil under pressure to oil burners.

Domestic oil burners present somewhat of a service problem, since they are frequently located substantial distances from a factory or shop where they may be serviced, and because it is frequently hazardous to permit the oil burner to remain out of operation for any substantial length of time due to the possibility of freezing water pipes, materials in process, to say nothing of the comfort and health of theinhabitants of the building in which the oil burner is located.

It is thus an object of my invention to provide an improved fuel feed unit for oil burners, which is of extremely simple design and which is constructed of a small number of parts so arranged that they are readily accessible for inspection, service, and adjustment in the field, thus making it unnecessary to return the unit to a factory or service station for repairs.

A further object is to provide an improved fuel unit in which the component parts and subassemblies are so arranged that damage or trouble with one component or subassembly does not necessitate replacement of a major portion of the unit.

Another object is to provide an improved construction in which the part or parts which are the cause of the trouble can be repaired or replaced without disturbing the setting or adjustment of other parts of the unit which are functioning satisfactorily, and in which most of the adjustments and replacements of components or subassemblies may be made without disconnecting any of the piping normally connected to the unit. For example, the fuel oil strainer,

the pumping mechanism, or the pressure regulating valve mechanism can be individually removed, cleaned, adjusted, and replaced without disconnecting the unit from the piping or removing the bolts that hold the unit on the burner. Similarly, a new pumping mechanism, together with its shaft, housing, and seal, can be mounted on the valve housing without in most cases requiring the disconnection of any of the piping.

A further object is to provide an improved fuel pumping unit incorporating a pressure regulating and bypass valve of the plunger type, in which both the plunger and its bushing can be quickly removed without disconnecting the unit from the burner, this facility for removal of the regulating valve being of particular advantage I when the fuel oil pumped by the unit contains impurities and foreign bodies which tend to cause the valve'to. stick or fail to seat properly.

A further object is to provide an improved fuel pumpingunit having an improved pressure regulating and bypass valve that does not require a press fit' of any of the valve parts, and which does not require holding means of the clamp typefor positioning them in the housing, such holding and positioning of the pressure regulating and bypass valve being accomplished by a combined valve seat and nozzle port providing element.

A further object is to provide an improved fuel pumping unit particularly adapted for use in conjunction with oil burners, which is extremely simple in construction, reliable in operation, and

'which may be economically manufactured.

Other objects will appear from the following description, reference being had to the accompanying drawings, in which:

Fig. 1 is an end elevational view of the pumping unit, with the end cap removed;

Fig. 2 is an end elevational view taken in the direction opposite tothat of Fig. 1;

Fig. 3 is a fragmentary sectional detail, to an enlarger scale, showing the internal fuel oil high pressure discharge ducts, and taken on the line 3-.-3 of Fig. 1;

Fig. 4 is a longitudinal sectional view taken on the line 4-4 of Fig. 5;

Fig. 5 is a transverse sectional view taken substantially on the line 55 of Fig. 4; and

Fig. 6 is 'afragmentary sectional view taken on the line 55 of Fig. 4.

In general, the fuel pumping unit comprises a gear pump assembly Ill having a shaft seal assembly l2 detachably secured thereto. pump assembly is detachably secured to a strainer and regulating valve'assembly M, the latter havin a pressure regulating valve assembly It retained therein by a, detachable combined valve seat-and outlet port l8.

Referring particularly to the gear pump assembly, it comprises a body 20 having a bore 22 extending longitudinally therethrough. The bore 22 is provided with a pair of keyway slots 24 to permit the ready removal of a drive shaft 2%, by providing clearance for the ends of a pin 28 extending diametrically through the drive shaft. This pin provides a separable driving connection between the shaft 26 and a gear 3% which meshes with its counterpart 32 to provide the rotating elementsof. a substantially conventional gear The gear pump. The gear 32 rotates freely on a stub shaft 34 pressed into the body 20.

As best shown in Fig. 5, the gears 30 and 32 rotate in a suitably conformed opening 36 provided in a casing plate 38. A cover plate 40 and the casing plate 38 are secured to the body by a plurality of cap screws 42. A removable screen 44 is provided with a rim 46 which has a sliding fit around the periphery of the casing plate 38. The cover plate 40 is provided with an oil inlet opening 48, which communicates with the opening 36 at 50, to the left of the gear wheels permit flow of oil to the uppermost and lowermost portions of the opening 36 to'improve the smooth running characteristicsof the pumQ- The discharge from the space 52 at the oppo- :preierablyma'de of a synthetic composition rubber, forming a valve face'for engagement with a seat I08 constituting part of the valve seat member H0. This valve seat member III) has a port I I2 leading from the valve seat to a tapped outlet opening II4, to which a discharge pipe is adapted to be secured for conveying the fuel oil under pressure to the burner nozzle.

site side of the gear wheels flows through a high pressure port 54, the latter communicating by way. of a duct 56, formed in the body 20, and a duct 58, formed in a regulating valve body 60, withan annular groove 62 to supply oil under pressure to the regulating valve assemblylt.

The drive shaft 26 is sealedbymeans; oiia sealing ring 64 preferably made of bronze or similar alloy, the sealing ring being structurally reinforced by a band 66 of steel or other highv tensile strength metal which is pressed over the sealing ring 84. The sealing ring 64 has anannular projection Bil which cooperatively engages w t ,r e,, e, a a e tNit a oy r similar material, which is pressedpvera seal ring I2, of steel or similar alloy, clamping a flexible diaphragm I4 between it and a fiangefl't "formed on the ring I2. The diaphragm "Ifm'ay be of any suitable flexible material, such as clothimpregnated with a plastic 'or similar material, which is oil resistant and ma es the clothsufficiently flexible to permit movement of the'ring l2 "and cause the ring I0'to maintain sealing engagement with the annular 'prtion B8 ofthe sealing ring 64 as the'latterwears. The'ring'IZ is pressed to the left by a'conical compres'sion coil spring I8, which is seated against aclosure cap 82. The'cap 82 clamps the'pe'ripheral edge of thediaphragm I4 to. the end of thebody 2i being secured to the body by a plurality ofcap screws 84.- I m The relative rotary movement thus takes place between the bronze annular-projection 68 and the ring I0 of Nitralloyorsimilar material, thereby providing an oil tight seal. If for any reason this sealneedsto be, repaired or replaced, it is clear that by removal of the capscrews 84 any component or subassembly of the sealing means may be removed for cleaning, refinishing, or replacement. 1

Similarly, if any of the components or subassemblies of the gear pump are not operating prop,- erly, the gear pump assembly may be removed as a unit by unscrewing cap screws 86 (Fig. oby which the body 20 is secured to the regulating valve body 60. In addition, upon removal of an end cap 68, by unscrewing cap screws'gsu, the strainer 44 may be removed for cleaning or replacement, whereupon the gear pump may be removed after unscrewing cap screws "42.

' Within the regulating valve body there is'aj bore 92 having a counterbore 94 at one end there-- of, part of this counterbore forming the'annu lar passageway 62 previously mentioned. "A regulating valve sleeve 96 has a chamfered shoulder 98 which has a sliding fit in the counterbo're' 94 and the chamfer surface of the sleeve presses against a sealing ring I00 which maybe made'of The valve I04 is urged to the right (Fig. 5) by a compression coil spring H6, one end of which has a spring seat H8 frictionally fitted thereto, the spring seat 8 having a conical point -I20 fitting-in 'a-wider angle conical depression I2I formed in the'inner end wall of the valve I04. The other end of the spring I I6 abuts against-an adjusting nut I22 threadedon a rotatable elongated fillister head stud I24. The stud I24 has a thin nut I26 suitably fixed thereto and is provided-with'a gasket I28, the kerfed head I30 of the screw I24 being accessible for engagement by ascrew driver through an opening I32 formed in abap1I3B, the latter beingsecured to the body (Why a plurality of cap screws I38.

The nut I22 is held fromrotation by a pair of pins I40 pressed in the cap I36 and projecting freely'through notches formedin the flanged portion'of the nut I22. It will thus be clear that by rotating the adjustingstud'I24 the degree of compression of the spring -I Hi may be varied so as to determine the pressure requiredto move the valve I04 from its seat I08. The valve I04 has an annular' groove I44 which'under all circumstances is in communication with the passageways I02. on'm the annular groove 62 has access to the face of the valve member I06 through a plurality of slots I46 cut in the end face of the sleeve 96. Thus, when the pressure at the outlet of the pump exceeds a predetermineddesirable value, the'valve I04 will move to the left (Fig. 4) to permit dischargejof the oil through'thenozzle connected outlet port I I2. 'Whenthe pressure becomes materially greater than the predetermined pressure required for proper discharge of the oil from the burner nozzle, the spring I IE will be further compressedand the annular groove I44 will form a. path for the flow of oil from the annular groove 62 through the ports I02 and the annular groove I44 to apluralityoffsymmetrically arranged ports 148 which are formed in the valve sleeve 96.

Theoil which thus enters the bore 92 may be returned to the fuel tank, or other source, through a pipe connected to a tapped outlet opening I50, the oil flowing past a plug I52, through a passageway I53. When'desired, the oil discharge into the bore' 92 maybe returned to a tapped inlet port I54 through a bypass duct I56, by removal of the plug I52 andinserting a solid plug in the tapped outlet I50. The oil from the tank or other source is supplied to the pump through a conduit connected to the inlet port 54, which communicates by way of a' passageway I'58' with the screenchamber I60. v

As best shown in Fig; 6, a tapped suction port I62 is pr0vided,-this port'bei-ng in communication withthe duct I58. The latter port is provided for the "attachment of-a*vacuum cause when municating via a duct I66 with the annular groove 62, the gauge thus being enabled to indicate the pressure generated by the gear pump, and assuming that oil is being discharged at the burner nozzle, it will also indicate approximately the pressure at which the oil is being discharged from the port II 2 to the nozzle, making. due allowance for the pressure drop in the piping leading to the nozzle. 7

From the foregoing it will be clear thatshould the regulating valve operate improperly -;for any reason whatsoever, the serviceman need. merely remove the cap IIO, whereupon the valve body I04 and all parts carried thereby, as well as the sleeve 95, may readily be removed, since these parts have sliding fits relative to one another and the sleeve 96 has a sliding fit in the body 60. Upon replacement of the sleeve 96 and valve I04, the sleeve is tightly sealed by means of the composition rubber ring I00, when the cap II is secured in place by means of its cap screws III. Suitable gaskets (not shown) may be used wherever necessary to assure oil tight seals between the Various separable parts.

It will also be understood, from the foregoing description, that the shaft seal may readily be removed and replaced without disturbing the gear pump mechanism or the regulating valve mechanism. Similarly, the gear pump may readily be removed with the shaft seal without disturbing the regulating valve or the shaft seal. For servicing the gear pump, the cap 88 and strainer 44 may be removed, thereby making cap screws 42 accessible and permitting removal of the gear pump. Adjustment of the pressures at which the valve I04 opens to permit discharge of oil to the burner nozzle and the pressure at which the bypass begins to take place are adjustable without removing any parts of the unit. If the gasket I28 for the adjusting screw I24 should leak, or if the valve I04, or any part carried thereby should need repair or replacement, the cap I36 may be removed, making all of these parts accessible for removal. When it is necessary to clean the sleeve 96 or to remove it for any other purpose, the cap screws I I I are removed, whereupon the cap I I0 which constitutes the outlet and valve seat, may be pushed to one side, with the pipe still connected to it, and the sleeve 96, together with the valve body I04 and parts associated therewith, may be removed. When it is desired to clean the screen 44, it is necessary merely to remove the cap 88.

It will thus appear that each movable component of the unit is readily accessible without in any way disturbing other components, and without making it necessary to disconnect the unit from any of the pipes or from the burner. The regulating valve may be utilized as a pressure responsive bypass from the high pressure side of the pump to the low pressure side thereof through the duct I50, or the oil which escapes past the pressure regulating valve may flow through the outlet I55 and pipe connected thereto to the source of oil.

Due to the provision of several radial ports I02 and H38, which are preferably, but not necessarily, equally spaced circumferentially of the valve sleeve 96, it has been found that the valve member I04 will not vibrate but instead will move smoothly and gradually to the position required for the maintenanceof the propercoperat ing pressure- Thus pulsations in the oil, flowing to -the burner nozzle are avoided. If such pulsations in the pressure fuelsupplied to the burner nozzle were present, they wouldcause unsatisfact rs oper io Qt h burner,

.The unit is thus ofextreme simplicity and ready accessibility ofits components. This ready accessibiltyof the parts of the unit isalso afactor contributing to low cost of. manufacture of the unitbecause of the rapidity with which the various partslmay be assembled. I

Whilel have shown and described particular embodiments of my invention, it. willbe apparent that" numerous variations and modifications thereof may be made without departing from the-underlying principles of. the invention. I therefore desire,'-by :the following. claims, to include within: the scope of my invention all such variations and modifications by which substantially the results of my invention may be obtained through the use of substantially the same or equivalent means.

I claim:

1. A pressure regulating device for the fuel supply system of an oil burner comprising a body having a main bore, a counterbore coaxial with the main bore and providing a shoulder at the junction of the two bores, a freely removable sleeve having a flange engaging the shoulder, the flange having a free sliding fit in the counterbore and the remaining portion of the sleeve having a free sliding fitin the main bore, said sleeve having a vent port in the wall thereof, a asket between the shoulder and the flange, a seat forming a, discharge port through which fuel is discharged to the oil burner, a piston valve having a close sliding fit in said sleeve and having a relatively wide annular groove spaced from its ends, means on the closed end of the piston valve to engage the seat at the discharge port, the major portion of the area of the closed end of the piston being subjected to the pressure of fuel supplied to the device when the piston is in position engaging the seat and the entire cross sectional area of the piston being subjected to the pressure of the fuel supplied when the piston is moved away from the seat, a spring compressed to hold-the piston in engagement with the seat as long as the pressure of fuel supplied is less than a predetermined value, a port in the sleeve to conduct fuel supplied to the annular groove in the piston valve, the vent port in the sleeve being located so as to communicate with the annular groove in the piston valve only when the latter has been moved by the pressure of the fuel a predetermined distance from the seat, and a removable closure secured to the body to hold the sleeve in position, said closure and body having fiat engaging surfaces whereby said closure may be slid laterally for removal, the removal of the closure making the sleeve, valve, gasket, and spring accessible for removal without disconnection of any pipes.

2. A pressure regulating valve comprising a body having a bore and having a portion of enlarged diameter at one end of the bore to provide a shoulder, a ported sleeve having a sliding fit in the bore and having a flange engageable with the shoulder, a gasket forming a seal between the flange and the shoulder, means for connecting the source of fuel under pressure to one end of the bore, a cylindrical valve member slidable in the sleeve and normally having its end face subjected to the pressure 01 the fuel supplied, said valve member having a groove cooperable with the ports in the sleeve, one port in the sleeve affording a bypass forthe fuel when the pressure thereof exceeds a predetermined maximum value, means providing a valve seat with discharge port, adjustable resilient means engaging the valve member and forcing it against said seat, and a single removable member holding the sleeve valve member and resilient means in assembled relationship within the body, said removable member and body having fiat engaging surfaces whereby said member may be slid sidewise for removal, said valve seat being movable with said member, the removal of the removable member making the sleeve, valve member, and resilient means readily accessible for removal without disconnection of any pipes.

.- CHARLES H. RYSTROM.

' i REFERENCES CITED The following'lre ferences are of record in the me of thispatent:

v UNITED STATES PATENTS Number Name Date 976,917 Richards Nov. 29, 1910 1,663,647 Brush Mar. 27, 1928 2,157,089 Storch et al. May 2, 1939 2,159,720 Wahlmark May 23, 1939 2,163,313 I Voit June 30, 1939 2,184,133 Wahlmark Dec. 10, 1939 2,212,833 Huber Aug. 27, 1940 2,232,983 7 Wahlmark Feb. 25, 1941 2,233,709 Osborne Mar. 4, 1941 2,309,683

Wahlmark Feb. 2, 1943

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