US1881012A - Pump mechanism - Google Patents

Description

2 Sheets-Sheet 1 ammer )Yi/ns e.

Oct. 4, 1932. s. wlLTsE PUMP MECHANISM Filed June 9. 1927 Oct. 4, 1932. s, wlLsE I ,1,881,012

PUM MECHANISM Filed June 9. 1927 2 Sheets-Sheet 2 l 72192 .l @ya 58 Y fra.

.Sumner )Yi/1156.

Patented @et 4, 1932 erica SUMNER WILTSE, OF DETROIT, MICHIGAN, ASSIGNOR, BY MESNE ASSIGMENTS, T

' EVANS APPLIANCE COMPANY,

A CORPORATION on MICHIGAN PUMP MECHANISM Application led June 9,

' rllhis invention relate-s to pump mechanism and particularly to a combined oil and fuel pump for internal combustion engines, the

principal object being the provision of apuni- Y 5 tary oil and fuel pump simple in construction, economica-l applied. f Another object of the invention is to providey a combined oil and fuel pump in which corresponding ends of a pair of housing inembers are each provided with a chamber for receiving one rotor of a pair of aligned rotors, each rotor terminatingin substantially the piane of the end of the housing in which it is received; the rotors are driven by acommon line of shafting; Y and the housing of one chamber closes the chamber provided in the other. l Y

Another object isto provide al combinedoil and fuel pump comprising a housing enclosing a sliding vane type pump element, a second housing enclosing' a similar pump ele- 'ment the vane-s of which are disposed at right-angles to the varies in the first pum g to Y manufacture and easily g5 element and which housing closes the first housing', a substantially Hat cap and cover lbeing provided for thesecond` housing enclosing a by-pass pressure relief valve for governing the maximum pressure capableof being` builtup bythe second pump element.

Another Objectis to provide a unitary oil and fuel pump comprising a single pair of rotors suitably housed and driven by aligned shafting, parts of which are suitably connectedtogether for equal rotation, a by-pass pressure relief valve operated by the outlet pressure of the fuel pump beinglprovi'ded for maintaining the pressure of the fuel as delivered to the carburetor at less than a pre-v determined maximum value.

Another object is to provide in combination with an internal combustion engine, a fuel pump positioned within the crankcase thereof, whereby the fuel passing through the same will absorb heat from the crank caseA and will result in a more economical and smoother running engine. K

'A furtherobject is to provide in combination with an internalcombustion engine, a

sm f

:1.1 unitary'mechanically ldriven oil and fuel 1927. k'senin No. 197,753.

pump provided with a common member therebetween, and operated within the crank case of the engine in such a position as to come in Contact with the oil therein whereby the fuel passing through the pump will be heated both by radiation of heat in the crank case and by conduction of heat from the oil pump part ofthe mechanism through ythe common member.

' The above being among the objects of the present invention, the same'consists in certain features of construction and combinations of parts to be hereinafter described with reference to the accompanying drawings, and then claimed, having the above and other `objects in view.

In the accompanying drawings which illustrate a suitable embodiment of the present invention, and in which like numerals refer to like parts throughout the several different views,-

Fig. l is a vertical sectional view taken transversely through an internal combustion engine provided with a unitary oil and fuel pump within the crank case thereof.

Fig. 2 is an enlarged side elevation of the combined oil and fuel pump shown supported within the crank case of the engine in Fig. l. v y

Fig. 3 is a vertical sectional view taken transversely of the oil pump shown in Fig. 2 as on line 3 3 of Fig. 2. v

Fig. 4 is a horizontal sectional view taken on line 4 4 of Fig. 2 showing the rotor 4and y on line y6 6 of Fig. 2 showing the rotor and' sliding vanes constituting the moving parts of the fuel pump of the present invention.

Fig. 7 is a View taken on line 7-7 of Fig. 2 being a plan view of the cover secured to the lower face of the pump.

Fig. 8 is a sectional view taken through the cover shown in Fig. 7 as on line 8-8 of Fig. 7, illustrating y,the by-pass pressure relief valve mechanism. n

The present invention is an improvement :01 discharge pipel 35.- leads from VtheY oil dison the construction shown and described in my application for Letters Patent of the United States for improvements in'pumps filed April 181511,1927, serial No. 184,573.

In accordancewith the present invention I have shownlnFig. 1 an internal combus- -tion enginey provided withV aunitary crank case upper half and cylinder blocky 10, cylinder head'11 and crank case lower half or oil pan 12: Rotatably i supported within the crank case of.` the engine is a crank'. shaft 13j connected by the conventional connecting rod 14 tothe piston 15 which is adapted to reciprocate within the cylinder 16,` formed within the cylinder block l0v upon rotation'` ofthe cra-nk shaft.13. The cylinder-16 1s connected bythe combustion chamber 117 to thefintake port 18 which in tur-n is connected ytothe intakejmanifold 19 which'. is provided with thensual carburetor 20. A valve 2l is positioned to-close the port 18 and is actuated by the cam 22 formedion the rotatable cam shaft 23 'through the tappet 24.,v A spi` ral bever gear 25 secured onthe camshaft` 23m-eshesfwith another suitable spiral gear 26secureidf'tofthe vertically extending shaft 27 ,suitably` supported. at its upper end by the bearing 28. Secured to the side of the crank case 10by bolts129 or other suitable rmeansyisga bracket30whichfextends down into the lower part ofthe oil pan 12 andremovably receives therein: acombined oil and fuel pumpy formedl in 'accordance withf'the presentinvention..

l A tube 31- connects the carburetor 2.0 vwith the fuel discharge side of'this pump-mecha*- nism, the tube 31f'passi'ngl through the crank case*- upper half` 10', whichv isv sealed-1' against' leakage aroun'd'thesame by means of a nipple such as32.y Af similartube 33connecting` p the; fuel'rintake side of. the pump mechanism with'arsour'ce of fuel supply, such as a; gaso- Vlfineatanlr (not shown), passes thro'ughthe crank case upper half 1() andl is sealed v against. leakagefby means ofa nipple' similar togni'pple 32 shown/"in connection with Atube` 31. A short tube 34 connects-thel oil inlet.

sidexof' thev pump mechanism with' the space inthe'fbottom ofthe" oilpan V12 andan oil charge side of the pump'unechanism tothe various'bearings of the engine. v

Asillustrated'in Figs. 2'to18 inclusive,- the pump` mechanism comprises a housing 36 providedwith externallbearing. portions and; 38Y adapted to be removably' clamped within? thelower'v en'di of the bracket; 30; Withinzthe housing' 36- and' opening into the bottom face thereof is arecess 39 circular in section. Positioned within the recess 39 eccentricall'ythereof is a rotor' 40 provided with a hub 41V extending upwardly.l into the casi-ng 36`-andprovidedfwith a suitable bear.- ing therein. ,A shaft 42 extending; axially down through the housing 36 and provided with a suitable bearing in the upper portion thereof, is loosely received within the hub 41 and is looked against relative rotation in respect thereto by the pin 43 whichloosely passes throughthe shaft 42. The lower end of the shaft 42 is provided with a tongue 44,

the purpose of which will presently be de-V scribed.

Secured tothe lower face 'of the housing 362by'means of the screwsl45is a second housing 46 closing the open end of the recess 39.

-Thelower face of the housing 46 is provided with a recess 47 similar to the recess 39, and

a rotor48 similar to the rotor 40 is positioned leccentric-ally therein, .a shaftv 49 being loosely secured to the rotor 481andfextending upwardly throughy the housing 46, 'whereit is,`

providedV with. a suitablebearing surface in axial alignment with .the shaft42: YThe upper end of the shaft 49 is slottedandv projects up through the rotor where'it is loosely re.- ceived and slidably lengagesthe tongueV 44 formedv on the :lower end of the shaft 42. A. cap 50 is shown. assubstantially hat, eX- cepting as if itis shaped toform a; valved bypass with thin metal cover 51'; and, a spacer member. 52 being 'optionallyA interposed, said cap' andcover may be secured to the lower faceof the housing 46 by meansvof screws such as 53.. Y

The rotor 40is provided withV a transverse slot 54 extending across the diameter thereof in alignment withthe tongue. 44 and for the full depth of the rotor 40,4 and slidably `Vreceived within. the slot-54 are two vanes 55. Positioned between the vanes 55 is aspring 5G which constantly urges the vanes 55 outward-v lyinto contactwith the side walls of therecess 39.y The projectin@ ends ofthe vanes 55 are bevelled offinthe direction` of rotation Vwhich is indicated by the arrow in Fig.. 4 for substantially the'fullwidth of the same, for a purpose ltobedescribed later. The rotor 40 isV of such. a diameter that the periphery thereof slidably engages thefside wall ofthe recess 39v on the line-indicated as `5'( in Figi. 4. v

Formed within the-walls'of 'therecess 39 on eitherV side of the line 57 f is the; inlet port58 and outlet yport 59., VThe inlet port-158 is convided, with va transverseslot. 63 yof similarV character to the slot 54previously described inl connection withthe rotor 40, and which slidably receives the vanes 64 which are shaped similarly to the vanes 55 and which are beveled off in the same manner and in the same direction, a suitable spring 65 being provided for constantly urging the vanes 64 apart and into Contact with the side walls of the recess 47 y It is to be particularly noted that the axial line of the vanes 55 and the axial line of the vanes 65 are at right-angles to each other, this feature being provided in order to equalize the `turning resistance between the same to provide a quieter running mechanism,and reduce the wear.

The rotor 48 contacts with the'side walls of the recess 47 along the line indicated as 66 in Fig. 6, in the same manner as the rotor 40 contacts against the side wall of the recess 89, and formed in the side walls of the recess 47 on either side thereof is the intake port 67 and outlet port 68, the inlet port 67 being `connected by the passage 69 with the exterior face of the housing 46 and to which passage 69 the fuel inlet pipe 33 is adapted to be suitably secured. The outlet port 68 eommuni- Cates with the exterior face of the housing 46 by means of the passage 70 which is adapted to be suitably connected to the tube 81 extending from the same to the carburetor. Openings 71 and 72 connect the ports 67 and 68 with the lower face of the housing 46, and openings 7 3 and 74 may be formed in acooperating part such as the mentioned cover member 5l between the cap 50 and housing 46 and in alignment with the openings 7l and- 72. Formed in the upper face of the cap 50 and extending between the openings 7 3 and 74 is a ymentioned by-pass passage 75 which passage is shown as completed by said cover member and as enlarged below the opening 74; and received therein is a coil spring 76. A disc 77 of larger diameter than the opening 74 and slidably received in the enlarged end of the passage 75 is shown as illustrating one type of valve element suitable to be constantly urged by the spring 76 upwardly against the under face of the member 5l in which position it closes the opening 74l from the passage 75. l f

Formed within the upper face of the housing 46 as indicated in Fig.v 5', is a groove 78 extending from the discharge port 59 to the bearing for the shaft 49 wit-hin the housing 46, the same groove being provided for conducting oil under pressure to the bearing in order that the same may provide a seal between the recesses 39 and 47. If desired, circumferential grooves such as 79 (see Fig. 8) may be provided in the bearing for the shaft 49 in order that oil may be conducted thereto from the passage 78 and better seal the recesses 39 and 47 from each other against the passage of fuel. Y

The operation of the device will be apparent from the above'description which, stated shortly, is as follows:

Upon rotation of the cam shaft 23, the gear 25 secured thereto is caused to rotate and in turn causes rotation of the gear 26 secured to the shaft 27. The shaft 27 is provided with a suitable type of sleeve joint at its lower end, provided with a tongue (not shown) which slidably engages the groove in the upper end of the shaft 42, thus causing rotation of the shaft 42. In rotating, the shaft 42 carries with it the rotor 40 which, as before eX- plained, is mounted eccentrically in the recess 39. In rotating, the vanes 55 seal the space between the rotor 40 and the side walls of the recess 39 and slide inwardly and outwardly of the slot 54 in order to accommodate the variation of the of the rotor 40 and the side wall of the recess 39. As each vane 55 rotates past the intake port 59 it creates a suction back of it, thus causing the oil to be drawn through the port 58 between the rotor 40 and side wall recess 39 and between the vane 55 and the line of contact 57, the succeeding vane 55 causing this oil to follow around each of the first mentioned vanes 55, and as soon as the first menwithin the'slot with their outer ends in contact with the side walls of the recess 47 in eX- actly the same manner as the vanes previously described in connection with the rotor 40, causing the fuel to be drawn in through the port. 67and discharged through the port 68. It is to be noted that the passages 7l and 72, openings 73 and 74, and the closed passage 75 form a continuous passage which, but for the valve disc 77, would allow fuel forced out of the port 68 to immediately return to the intake port 67, thus preventing any pressure from being built up in the fuel pump. The spring 76 is provided for controlling this return flow of fuel between the ports 67 and 68, it being so proportioned that until the maximum desirable pressure is built up in the discharge passages of the fuel pump, the disc 77 will remain seated and close the opening 74, butis so designed that as soon as this maX- imum desired pressure is built up, the disc 77 will be acted upon by such pressure, and will be moved away from the plate 51 thus allowing the excess fuel to flow from the port 68 through the passage 75 and back to the intake port 67.

Inasmuch as the volume of fuel pumped by space between the outer edge this type of pump varies in proportion to the yspeed-of the same, it Will be'apparent that in order to obtain the necessary fuel requirements-atlow speeds of the engine thata pump V5 must' be provided Which will supply a volume of;fuel at high speeds greatly in excess of the amount needed. In order to prevent the press'ureonthe discharge side of the pump from building up over the desired maximum presimsurefvvhich fory fuel pumps is seldom over one and one-half to two pounds, the openings 73., and 74 andthe. passage? 5 are designed with ample dimensions to. prevent anyy lappreciable restriction in the flow of fuel therethrough aty high speeds so that there Will be n determined pressures, the vanes recede slightly from the 'Walls of the correspondingr'ecesses 39 and 47, thusaiding in slightly reducing the pressure built up, andin receding from the Walls of the recesses substantially eliminatevvear on the ends of the varies.`

' It will be recognizedthat leakage of fuel past the shaft 49 and intothe oil pumprecess the lubricating oil Whichfmight lead to serious results. In order to prevent such a possibility, theV groove .78 is provided for conducting voilfrom the discharge port 59 of the oil pump vto the bearing for the shaft 49 in the housing 46. Because of the superior pressure of the lubricating oil, a small amount of such oil is forced int'o'con'tact vviththefshaft 49, and not only serves to lubricate thev same in its bearing in the housing 46, but also provides an effective sealfor preventing leakage of'fuel therepast. f f

As above described,fthe shaft'42 is providedwith a relatively close fitting bearing in the upper end of the hous'mg 36 and is loosely received Within the hub 41 of the rotor 40 which hub is provided with a relatively close bearing Within the lower portion of the housing 36. Thisprovides a construction very'ec'onomical to manufacture inasmuch as no particular pains need toV be taken for perfectly aligning the bearings for the shaft 42 and the lhub v41, and but tvvo relatively close 'fits are necessary for the same. ln addition,

Vnofparticularly accurate machinework is required at'y this point. The groove Within the upperfend ofthe shaft 49 may be suitably l relieved so that, the vanes 55 slidaloly passing, 6?, through' the same arefreeof any tendency to 39 would allowcornmingling .of the fuel With;

the shaft 49 loosely receives the tongue 44 and bind therein, and no particular precision is necessary in connecting the housings 36 and 46 together. Y j Y A particularly important feature of the present invention Vis the positioning of the mechanism within the lower kparte of the oil pan l2,`and preferably below the normal level 8O of the' oil therein. The advantages Yrealized. by this feature of the invention are lthat the fuel passing through the'pumping mechanism is heated and ample lubrication is provided forthe bea-ring` for the shaft 42 therethrough passesdovvn through the housling 46, heating the same, and causing the fuel passing therethrough to be heated. The

housing'46 and'cap 50, Wherethe same are positioned above the norma-l levelof the fuel, are also heated by the spray of oil from the bearingsl of the engine, which comes in contact With the same. By thus heating the fuel being fed to thecarburetor 2O more complete vaporization of the same is obtained with the resulting. smoother and more economical performance of the engine. I

Formal changes'may be Vmade inV t-hey spe-l ion cie embodiment of the invention described n Without departing from the' spirit and'substance of the broad invention, the scope of which is commensurate With the appended claims. v

What I claim is; p Y

l. A fuel and oil pump having, in combination, anoil pumpcasing, said casinghaving a pump chamber eXtendingto an end thereof, Vsaid casing havingan oil inlet and an voil outlet communicating with the chamber, an oil pump rotor'bearingin the casing, said Yoilpump rotor having ya bore, and having an end in substantially the same planeas the corresponding end of said casing, a drive shaftin the bore non-rotatably connected to the oil pump rotor, afuel pump casing so formed and attached tothe oil pump casing as to close the mentioned chamber, the fuelv pump Vcasing having an inlet opening, a pump chamber extending to the corresponding end thereof, and an outlet opening, a fuel pump rotor terminating substantially in the plane of said corresponding lend and bearing in the` fuel pump casing, lsaid fuel pump `rotor having a bore, and a driven-shaft non-rotatably connectedatV one end Vto the'fuel pump rotor and extending atthe other end f into the oil pump chamber and non-rotatably connected chamber and being a single line of shafting to the drive shaft, and a substantially flat cover for the fuel pump chamber.

2. The combination in claim 1 in which the fuel chamber is provided with a cap which contains a duct and has a relief valve therein, an apertured cover being interposed beneath saidrcap, and said duct leading from the inlet to the outlet of the, chamber, whereby to bypass the fuel upon an overload.

3. A pump structure comprising a pair of approximately aligned pump casings hav ing pump chambers formed therein, a partition separating the chambers, a pump rotor in each chamber, a shaft interconnecting the two rotors, each end of the shaft being slotted and one slotted end projecting into one of the rotors and a transversely disposed impeller blade extending outwardly from the outer peripheryof said one of the rotors and being disposed in the last-mentioned slotted end of the shaft.

4. A pump structure comprising a pair of approximately aligned pump casings having pump chambers formed therein, a rotor disposed in each chamber, a shaft connecting the two rotors, one end of the shaft being slotted and extending through an opening in one of the rotors and being engaged by a tongue upon a drive shaft, said slot also receiving an impeller blade extending transversely through the last-mentioned rotor.

5. In combination: an oil pumpl comprising a housing which provides a pump chamber at an end thereof and a single rotor disposed in said chamber and terminating in the plane of said end; a fuel pump comprising a housing having an inlet opening and an outlet opening and a single rotor, an end of the last mentioned housing cooperating with the first mentioned housing to close the oil pump provided in its other end with an additional chamber; a substantially flat cap for closing said last-mentioned chamber; cooperating parts embodying a by-pass pressure relief valve for said fuel pump; and for driving both of said rotors, a tongue and slot being respectively provided for cooperation at adjacent ends of parts of said shafting and a vane of said oil pump being slidably received in said slot.

SUMNER WILTSE.

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