US2581764A

US2581764A - Metering fuel pump

Info

Publication number: US2581764A
Application number: US789106A
Authority: US
Inventors: William E Leibing
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-12-01
Filing date: 1947-12-01
Publication date: 1952-01-08
Anticipated expiration: 1969-01-08

Description

Jan. 8, 1952 w. E, L EIBING METERING FUEL PUMP Filed Dec. l, 1947 I il Jam v8, 1952 A w. E. LEIBING 2,581,764

METERING FUEL PUMP Filed Dec. l, 1947 2 SHEETS-SHEET 2 d f1.9 JI;

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.rraHA/Egs Patented Jan. 8, 1952 UNITED STATES PATENT GFFICE j METERING FUEL PUMP' William E. Leibing, Los Angeles, Calif. Application December 1, 1947, Serial No. 789,106

2 Claims.

This invention relates to fuel delivery pumps for4 use in connection with internal:v combustion engines of the type employed in automobiles, trucks, buses, aircraft, and' marine applications.

It. isy the principal object of this invention to provide a fuel pump of novel design which functionsy not only to supply liquid fuel to the engine but also to meter the rate of iiow to conform to the exact requirements of the engine under all conditions of' operation.

A related object is to eliminate the carburetor and fuel pump as conventionally employed in connection with the internal' combustion engines of the manifold induction type and to replace these two units with a single fuel pump unit capable a 'pump adapted to deliver fuel into the engine' manifold, and having a pressure responsive means in communication with the manifold adapted to control the rate of fuel delivery from the pump.

A further object is to provide a fuel pump of this type which may be positioned at a remote location with respect to the engine if desired',v so that the fuel while being metered and pumped is not subjected to the heat of the engine.

Another object is to provide a metering fuel pump which. may be economically manufactured in quantity,4 and which is adaptable to engines of wide variation. in capacity.

Another object is to provide a device of this typev which delivers fuel at. a metered rate into the engine manifold either anterior or posterior of the throttle valve controlling air flow toy the engine. Other objects and advantages will appear' hereinafter.7

In; the: drawings:

Figure 1 is a diagrammatical side elevation showing a preferred. embodimentof my' invention, and' in which multiple discharge conduits enter the intakemanifold at spaced locations.

Figure 2 is a viewV similar to Figure l. showing a singie discharge conduit entering the. intake manifold at a location anterior of the throttle valve.,

Fig-ure 3is1a view similar to Figure 2 but showing the discharge conduit'. entering the' manifold at apostion; posteriorA of the throttle valveL Figure 4; av side elevation. of a: metering fuel pump embodying my invention.

tially on the line 5-5 as' shown inFigure 4 5,

' the bearings 26 and 21.

Figure 6 is' a1- transverse sectional view partly broken. away.

Figure 'l is, a sectional elevation taken substantially on the line 'I--l as shown in Figure 6.

Figure 8 is an enlarged. sectional-"view partly broken away showingI details of constructionvof one of the pumpvunits.

Figure 9 is a sectional view of one of the deformable ring elements shown in Figures 6 and 8 J as it appears before assembly into one of the pump units.

Referring to the drawings, the pump unit I 0 includes a housing I I' provided with an end cap l2 and a closure I3. rEhe end cap I2 is connected to the housing I I'v by means of an intermediate spacer I4. The spacer I4 may be connected to'y the' housing flange. I5 by means of a series of threaded elements I6'. Another series of threaded elements I'I- serves to connect the end cap I 2 to the spacer I4;

As shown in Figurey a non-rotary ring I8y is pivotally connectedl to the housingv II by means of the pin I3 secured to the housing II,H and is Y adapted` to be rmoved* laterally within the housing by means of the linkagev generally designated 20. A raceway 2l' is provided on the inner circumference of the ring I8, and `mounted in this raceway are a plurality of rollerI elements such as the balls 22..v A rotary sleeve 23 supported onthe roller elements 22 is adapted to turn within the non-rotary ring I8. Mounted withinl the rotary Vsleeve 23 is a rotor assembly generally designated 24. The rotor assembly 24 includes a shaftJ 2liV projecting outwardly throughl the end cap I2 at one endand adapted to rotate` within The bearing 26 iscarried by the end cap I2 andthebearing 2:1 is mounted withinr the closurel I3. l .Y

A` keyway 28" is provided in` the projecting end of the shaft 25 for connection to any suitable drive means, such as, for example, a eXible drive shaft, a pulley, sprocket or gear. While any of these conventional drive means may be employed for turning the shaft 25, it is to be understood that this shaft is driven at a speed proportional to the engine speed, so that variations engine speed are directly proportional tor variations in the speedA of. rotation of the` shaft 25. A preferred form of driving connection consists. ina flexible sha-ft (notl shown) connecting the shaft 25 to the cam shaft of the internalI combustion engine'. Y

The rotor assembly 24 includes a rotatable body 29 fixed on. the; shaft 25.- and provided with a pluralityof reciprocating pump units. generally designated 39. These pump units 38 are duplicates, and while I have shown that eight of these are provided in the body 29, only one will be described in detail. Each of these pump units 38 includes a piston 3| adapted to reciprocate within a radial bore 32 provided in the body 29. A

and deformed or crimped to maintain it in position. The shape of the ring before such deforma- Y tion is shown in Figure 9. The ring 38 is provided with a central aperture 39 and a plurality of breather ports 49. L

' .The pistonY generally designated 3| is provided with a centralopening 4| adapted to receive a compression spring 42 normally acting to move the' piston 3| outwardly within the bore 32. A cap V4 3 having a'contact surface 4l! at its outer endisthreadedly mounted on the upper portion of y the piston 3| andserves to confine the inner portion of thediaphragm 35 between the washer 45 and the shoulder 46 on the piston 3|. rlhe cap 43 is provided With an outer cylindrical surface 41 adapted to reciprocate within the aperture 39 in the'r'etaining ring'38.v From the above descriptionrit will be understood that the piston 3|, cap4 3 'and washer 45 may reciprocate as a unit within the cylindrical bore 32, flexing the diaphrag'm 35.

Rotation of the shaft-25 and the body 29 carries'the rotatable sleeve 23 around at the same timeA byu reason of the frictional contact between the surfaces 44 on the end caps'43 and the inner lsurfacel 48 ofthe sleeve 23. The sleeve 23 turns within the non-rotary ring |8 on the anti-friction b all'elements 22.

MYVMeans are provided forshifting the non-rotary ring |8 and the rotary sleeve 23 in a direction transver'seto the axis of the rotary shaft 25. The purpose of shifting the ring and sleeve is to develop eccentricity between the rotor assembly 2d andthe sleeve 23, so that each pump unit 3U operates as therotor revolves. As shown in Figure Vof the drawings, a link 59 is pivotally connected Vat 5|' tothe non-rotary ring 8 vand is pivotally connected to the lever 52 at 53. A crank pin 54 fixed to the actuating arm 55 is also fixed tofthe crank arm 56 within the housing A'compression spring 5| is provided for the purpose of resiliently urging the crank 58 to move in a clockwise direction as viewed in Figures 5, and hence to contact the inner end of the threaded stop,` element 58. The stop element 58 may be adjusted to the desired position and xed by means of the j am nut 59.

g A pivot pin 60 serves to connect the crank 56 with the lever 52. A pin 6| at the upper end of the lever 52 connects the lever with a movable member 62 mounted centrally of the control diaphragm |53.l This control diaphragm is clamped in position between cooperating

flanges

64 and 65 provided on the housing I I and cap 6E respectively. VThe cap 66 is shaped to provide a cavity or chamber B1 therewithin on one side of the diaphragm 63 and positioned within this chamber is a compression spring 68. One end of the spring 68 engages the follower element B9 which is secured to the member 62. The other end of 4 the spring engages a movable seat 18. An adjusting screw 1| threaded through the end wall 12 of the cap 65 is provided in adjusting the compression of the spring 61, and a jam nut 13 is provided to hold the screw 1| in adjusted position. A threaded opening 14 extending through the wall of the cap 56 communicates with the chamber 61. As shown in Figures l, 2 and 3 a transfer pipe communicates between the opening 14 and the interior of vthe intakefmanifold 16 of the engine. The transfer pipe 15 enters the intake manifold at a location downstream from theA o is communicated to the chamber 61. The resulting reduction in absolute pressure within the chamber 61 enables atmospheric air pressure in the left side of the diaphragm 63 as shown in Figure 5 to'move the diaphragm 63 and member 62'to the right against the action of the force of the spring 68. Movement of the member 62 to the right causes the lever 52 to pivot about the pin 68 and, hence move the link 59 and lower portionof the ring |8 toward the right. This action reduces the eccentricity of the ring I8 and sleeve 23; hence reduces the stroke of each of the pump units 38.

As shown in Figure 6, each of the pump units 39 is provided with inlet and

discharge ports

18 and 19 which are formed within the body 29.

These pairs of

ports

18 and 19 each meet at a V series of common junction ports 89.A Four of these ports extend through the end surface 8| on the Vbody 29 and an additional four of these ports 80 extend through the end surface 82. ,A non-rotary washer 83 is adapted to contact the end face 8|, and a similar non-rotary washer 84 is adapted to contact` the end face 82. Each of these Vwashers is preferably formed of resilient material, and the faces 82 and 8| are smoothly finished and then lapped to insure .la smooth fiat surface. Each of the washers is provided with a pair of laterally extending ears 85 adapted to be received in corresponding recesses 86 in the nonrotary port members 81 positioned at opposite ends of the housing The members 81 are substantially duplicates, and .accordingly only one needvbedescribed. Each of these members 81 is provided with a central opening 88 encircling the shaft 25 and providing clearance therewith.

A counterbore 89 receives the washer 83. Communicating with this counterbore are inlet and discharge ports 90 and 9|. These ports communicate with

semi-circular grooves

92 and 93 formed in the washer 83. '

I'he grooves

92 and 93 do not meet but are separated by relatively short dikes 94. As each of the junction ports 80 revolves it is alternately placed in 'communication with the

grooves

92 and 93, and hence except for the interval when it is passing over the dikes 94 it is in communication with the inlet port 90 or the outlet port 9| provided in the member 81.

Since it is very diicult to obtain a smooth flat end surface on a rotating member which is exactly at right angles to the axis of rotation, there is always the possibility that the surfaces 8| and 82 'may be slightly out of square with the axis of the shaft 25. Accordingly, I prefer to employ

washers

83 and 84 which are resilient in character,` and further to provide resilient mountings for the members 81. Each of the members 81 includes a pair of projections 95 extending outwardly through apertures provided in a flexible diaphragm-9.6. Diaphragmst96 are confined between the'. end member I'2i and spacer It, and between theclosure I3'andthefhousing. I I respectively; Diaphragme Elliy function. toI prevent rotation of the' members. 81: and also. to` allow them` to oscillateslightly if rl necessary as the. rotor 'assembly 2l turns inl order to'r maintainl optimum sealing-f characteristics between the surface 8l' and the'. washer 83 and betweenthe surface 82v andthe washerl 8'4. A nut Sl' is threadedly mounted on each of; the'. projections 952 and serves to compress alsealing washer 98 againstthe surfacelof the diaphragm 96. A spring 99 encircles a portion of each of the projections 95- and serves to provide the proper contact vpressure between the washers and the sealing surfaces 8l and82.

l Separate cavities H30 and I 0I are provided in Athe end' cap' I2 for' communication with' the' outlet port 9| and inlet port 90 respectively. Similarly, separatecavitiesitz andi 103? are provided in the closure I 3 for communication with the outlet port I Il@ and inlet-port |125. A passage IDS extending through the end cap I2, spacer -IA, housing II, closure I3 and` through the diaphragms. llt-and gasket IM- servesto connect the inlet cavities iI and H33 with. the inlet opening I08 at the lower central portion of the housing II. An inlet pipe IUS as shown in Figures l, 2 andY 3, serves to connect the opening HI8 with the fuel tank I I0.

The outlet openings II I and II2 provided in the end cap I2 and closure I3 communicate with the outlet cavities IUD and H12` respectively. Discharge pipes II3 and I I4 connected to the openings II I and I I2 respectively are adapted to'communicate with the inta-ke manifold. Asshown in Figure 1, these discharge pipes IIS and Iltmay communicate with the intake manifold at spaced points downstream from the throttle valve TI. As an alternate arrangement the discharge pipes II 3 and II4 may enter the manifold at a common point downstream from the throttle valve 'Il as shown in Figure 2. As a further example the discharge pipes H3 and II4 may enter the intake manifold at a common point upstream from the throttle valve 11 as shown in Figure 3. The pump assembly I Il as shown in Figures 1, 2 and 3, is illustrated as being in close proximity to the intake manifold, but is contemplated that the pump may be placed at any convenient point, away from the heat of the engine if desired. The pump I9 may be placed above or vbelow the tank I I Il.

The interior of the housing I I may be illed with a light oil if desired, and a filler opening I I5 is provided for introducing such oil. A plug I2I may be utilized to close the opening II5. The seal between such plug and the opening I I5 is not intended to be air tight, however, since it is desired that the interior of the housing II be maintained at atmospheric pressure. A seal ring I I 6 of conventional type may be employed within the end cap I2 to prevent escape of lubricant from the interior of the housing II along the shaft 25. Leakage of fuel from the passageways 8D across the sealing surfaces 8l and 82is prevented by the Contact face of the

washers

83 and 84, the fuel serving as a lubricant for the faces 8| and 32 to provide an effective seal.

In the normal operation of the device the diaphragm S3 remains in its retracted position as shown in Figure 5, while the engine is idling or operating under substantially no-load conditions, since the vacuum pressure is high at such times. If the engine is speeded up under light 6 load? or no-load conditions, the diaphragm remains substantially in. the same position since the vacuum pressure as reflected in the chamber 5l' remains high. The engine receives the proper amount of fueLhowever, since the speed of rotation of the'rctor assembly 2e increases. directly with increase in the engine speed. When a load is applied to the engine when: it is turning at either high' or low speed, the vacuum pressure diminishes, raising the absolute pressure within the chamber bl and allowing. the spring 68 to move the diaphragm 63 to the left. This motion results in pivotal movement of the lever 52 in a counterclockwise direction, hence shifts a ring i8 to the left to increase the pumping stroke of each of the pump units 3U; In this way more fuel is delivered when additional load is applied to the engine. Conversely when the load on the engine is lessened themaniold suction pressure increases and the ring t8 is moved to diminish the eccentriclty, and hence reduces the strokev of each of the'pump units i.

The control arm 55 is providedor the pur'- pose of securing greater fuel delivery rates from the pump under cold starting conditions. rI'fhus when the engine is cold the control arm 55 may be manually pivoted in a counterclockwise direction as shown in Figure 5 to compress the spring 5l and move the lower end of the lever 52 toward the left.V This increases the eccentricityV of the ring iB and sleeve. 23, and hence results in a greater rate of flow of fuel to the engine.

It is well known that the optimum fuel-air mixtures at sea level are less eiiicient at higher altitudes, and it is necessary to reduce the amount of fuel in the mixture to secure proper engine performance at higher altitudes. In accordance with a feature of my invention, I prefer to provide means for automatically limiting the maximum` rate of fuel.y delivery from the metering fuel pump in relationl to changes in atmospheric pressure.

As shown in Figure 5 a metallic Sylphon bellows II'! is sealed at both ends containing an inert gas at atmospheric pressure, the gas preferably-being one with a low coeflicient of temperature expansion. The metallic bellows II'I is preferably mounted within the housing II and carried on an adjusting screw II8 provided with a jam nut I I9. 'Ihe adjusting screw is positioned so that at sea level the contact lug E20 on the ring I8 just begins to engage the free end of the bellows II'I when the ring I8 is in idling position; that is, at a Very small eccentricity. When theengine operates at elevations above sea level the force exerted by the bellows against the contact lug I20 remains substantially constant for any particular position of the ring i8, while the force exerted by reason of the differential in pressure across the diaphragm 63 is reduced, owing to reduction in pressure on the atmospheric side of the diaphragm 63. The effect of the force exerted by the bellows II'I therefore increases as the atmospheric pressure decreases. Accordingly, at any altitude at which the engine operates the maximum correction occurs at full throttle, and from full throttle the bellows I VI acts on a diminishing scale down to idle position.

It will be understood that various changes in the mounting of the bellows may be made without departing from the spirit of this invention in order that the bellows may be made effective under any given range of movement of the ring I8, as desired. The position of the ring I8 at any given instant is determined by the balance of forces exerted by the bellows I l1 and the link 502 The spring rate or relative stiffness of the bellows I l1 is chosen so that it is effective in resisting to the proper degree the resultant force applied by the diaphragm 63 and spring 61. v

Having fully described my invention, it is to be understood that I do not wish to be limited to the details herein set forth, but my invention is of the full scope of the appended claims.

I claim:

l. In a fuel pump, the combination of a casing; a rotor within the casing; pump means on the rotor, the rotor having a plane end face provided with ports communicating with said pump means; valve means including a, nonrotatable ported washer adapted to contact said end face in sealing relation; a support member for said washer, said member being provided with inlet and outlet passageways communicating with said ported washer; a diaphragm positioned in sealed relationship with respect to said casing; means whereby the support member is carried on the diaphragm; and resilient means acting on the member to maintain pressure between said ported washer and the rotor end surface, the resilient means and diaphragm cooperating to provide a iiexible support for said member and washel` to accommodate any wobble of said rotor end surface. f

2. In a fuel pump, the combination of a casing;v a rotor within the casing; pump means on the rotor, the rotor having a plane end face provided with ports communicating with said pump means ;y valve means including a nonrotatable ported washer adapted to contact said end face in sealing relation; a support member for said washer, said member being provided with inletI and outlet passageways communicating with said ported washer; a diaphragm positioned in sealed relationship with respect to said casing; means whereby the support member' is carried on` the diaphragm, said means including a plurality of radially spaced projections extending axially through the diaphragm, said member being provvided with inlet and outlet passageways com- WILLIAM E. LEIBING.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 557,395 Kelly et al Mar. 31, 1896 1,427,716 Bluhm Aug. 29, 1922 2,153,559 Hendricks Apr. 11, 1939 2,233,035 Schweizer et al Feb. 25, 1941 2,244,669 Becker June 10, 1941 2,292,181 Tucker Aug. 4, 1942 2,293,692 Wylie Aug. 18, 1943 2,341,257 Wunsch Feb. 8, 1944 2,351,732 Almond et al June 20, 1944 2,376,016 Schnell May 15, 1945 2,397,314 Grosser Mar. 26, 1946 2,406,138 Ferris et al Aug. 20, 1946 2,414,617 Summers Jan. 21, 1947 2,439,498 Wallace Apr. 13, 1948 2,458,985 Ferris et al Jan. 11, 1949 FOREIGN PATENTS Number Country Date Great Britain 1940