US1687518A - Fuel pump and oil-injection system for internal-combustion engines - Google Patents

Description

Oct. 16, 1928.

- P. L. sco'r'r FUEL PUMP AND OIL INJECTION SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed Dec; 1 92 2 Sheets-Sheet v jnverztgr PfiiZZi L. Scan? Z37 Mtforneg;

Oct. 1 6, 1928. 1,687,518

P. L. sco'rT FUEL PUMP AND OIL INJECTION SYSTEM FOR INTERNAL. COMBUSTION ENGINES Filed Dec. 1'- 1920 2 Sheets-Sheet 2 fizz'erazfor I \a My. M

, Patented a. 15, 1928;

" UNITEUSTATES PATEnT OFFICE.

' PHILIP LANE SCOTT, OF CHICAGO, ILLINOIS, ASSIGNOB TO SUPER-DIESEL TRACTOR CORPORATION, OF LA POBTE, INDIANA, A CORPORATION OF NEW YORK.

rum. rum AND OIL-INJECTION sYsrEia non mrnniuri-comnus'rron moms.

Application fil ed December My invention has to do with the pump and the pipe and connectionswhereby I am enabled to inject oil or fuel into an internal combustion engine by pressure applied to the fuel itself alone and without the use of any air pump or jet orany other additionalapparatus.

One object of my invention is to provide an arrangement whereby any entrainment of foreign materials such as air, gas and the llke may be prevented. Another object of my invention is to provide means 'whereby the system may be automatically and'continually cleared of any air, gas or other foreign substances and thusa ny air dome action may be prevented. Other objects of my invention will appear from time to time.

In dealing with my invention it must be remembered that I am planning on what I prefer to call solid injection of a liquid under the influence of hydraulic pressure only for the purpose of breaking up or atomizing the liquid. The more incompressible and solid the liquid is, the better will be the action and the presence of gas in appreciable quantities is sufficient to make my spray and atomizing action become either in-operative or exceedingly unsatisfactory. Th1s is true of all pump systems in general of this kind and that means that the inclusion of even a slight amount of gas or air may become exceedingl v disadvantageous. This difficulty arising from too great compressibility of liquid is important even where injection with air is used, as for instance it might result in too great a proportion of the pump stroke being used up before actual discharge took place, or it might result in such a changing of the timing that the injection would not take place 1n time to fit in with the engine cycle and these difliculties are greatly accentuated when solid injection into the engine itself is relied upon as in the case in my apparatus.

This difficulty arising out of thepresence of gases in the liquid may take a number of forms. This difficulty arises from the fact that all of the oil with which we deal always C.'31i.1'iDS a certain amount of air or other gas in solution in such minute quantities that it practically if not actually impossible to get rid of them mechanicallyx These gases may be in such small bubbles that they cannot be seen and the only way to avoid difiiculty arising from this situation is to arrange to handle under pressure the smallest possible solu- 1,1920. Serial no. 421,642.

tion of liquid and to arrange to inject-under pressure as large, a proportion of the volume subjected to pressure as possible.

Another form ofthe gas ditficulty arises from the fact that when the temperature rises, for instance when the oil goes into the warm oil pump or when the pressure drops as onsuccessive strokes, this gas or air may be found to form appreciable bubbles and these bub bles mayor may not join themselves to bubbles of air introduced by leakage in the suction system or improper handling during the operation. This may and frequently does result in the presence in the system of relatively large air or gas'bubbles and there are four forces gravity, entraining, drop 7 in pressure, and warming, which may be used in getting rid of these bubbles. The first'is that Ill heating the liquid and reducing its pressure both tend to separate out and to liberate from the liquid the gas or air which may be therein contained; the second is that. gravity acting perhaps more slowly will-segregate the separated gas or air bubbles and the fourth force available is the entraihing power of a rapidly moving stream or column of oil which can be used to pick up and carry away the segregated bubbles of air or gas. i

In order then to take advantage of the two forces which can be used to keep the system clear of bubbles it is desirable first to place the mechanism which is to be used in remov ing the air at the high point in the system so as to gain the benefit of gravity, and it is necessary toprovide means for the movement of as large a body of oil as is possible toward this point. In order that gas or air bubbles may not be entrapped or left at any point short of the place where they are to be separated out, it is desirable first to provide a' system where there shall be no re-entering places or corners, no pockets where the air may stagnate, no places Where the air may be caught and held by gravity audit is necessary to provide a system where the oil has relatively high velocity at all times. In addition to this, it is necessary that the passageor'aperture through which that art of the oil which is going to be actually urned in the engine or discharged into the engine be placed as far from the point where the air laden oil should discharged as 'is' convenient because in my apparatus it is necessary that whatever part of the oil is discharged conveying away with it, this unwelcome air,

diagrammatically none of it shall find its way to the spray valve because if it tried so to do this would result in immediate air binding or other unsatis-.

factory operation at thespray nozzle. It also seems best that the air laden oil be discharged Figure 3 is a section along the same plane I as Fig. 1 showing the pump or plunger driving mechanism igure 4 is a section along the line 4: 4 i

of Fig. 3.

A is a pump casing. It includes a pump cylinder A in which is mounted for reciprocation a pump plunger A having a tapered nose A This pump casing contains Within 4 power source, if the atomizer is used in conits walls a plurality of pockets or sockets to contain the various valves and connections which will later be disclosed. A is a socket in line with the pump chamber itself adapted to contain a bypass or valve housing. A is a socket at right angles to the valve cylinder adapted to contain an inlet valve housing, and A is a socket at right angles to the pump cylinder and the socket A adapted to contain a discharge valve housing. The valve cylinder communicates directly with the socket A and with the sockets A and A, almost directly through the exceedingly short passages A and A whose arrangement is such that the housings contained by these sockets are as close to the pump plunger as possible. Y

Extending rearwardly from the end of the pump housing A is a housing. B having a pair of brackets B, B. These brackets form a frame-work in which the cam shaft B is mounted for rotation. This cam shaft is driven from the engine or from some other nection with devices other than engines, and by any suitable power transmission connection not here shown. B is a cam rigidly mounted on the cam shaft. The face of this cam is in contact with the roller B which roller is in turn mounted upon a. pin 1? and this pin is connected to a cross head or carrier B, which cross head is slidably mounted in the cylindrical bore 13 in the housing The cro head having the extended lugs B" and Zlotted at B to allow guidance onthe shaft B B is a ball substantially spherically mounted on the crank end of the plunger A. B is a yoke or spring B to en a'coi'led spring surrounding the cap B and adapted to be compressed between the collar B and the pump housing. B is a projecting-forward from the cross head that as the cam rotates the piston is forced forward, a rigid drive being applied through the pin B to pump in a forward direction as the cam. As the cam goes through the piston or plunger is drawn back by the spring B.

C is the intake valve housing. It is seated in the socket A by means of a yoke C, and anchor bolts C This housing is provided at its inner extremity with a beveled valve seat C upon which is seated a conical intake valve C, this valve being held upon the seat by the coiled spring C and guided as it reciprocates by the vanes C The inner face of the valve block, that is that part which is removed from the beveled seat is conical in shapeas shown at C there being a series of small lugs-C projecting from the conical face. The face of the socket A is also conical to conform to the conical face of the valve the arrangement being such that when the plunger A is drawn back the suction will unseat the valve but the valve will be held away from the conical bottom of the socket so that there is a free passage for oil in through the intake valve housing across the beveled seat, around the conical end of the valve into the plunger chamber or valve cylinder. 0 is a pipe leading from any suitable source of oil supply whereby oil may be drawn up into the pump cylinder .through the valve housing.

It willbe noted that the point at which the intake part of the system communicates, the valve cylinder is at the bottom of the cylinder so that any entrained air or gas bubbles will pass right through the intake system up into the pump cylinder and there will be no tendency for any air or gas bubbles to be pocketed anywhere within this part of the system. a

D is a discharge valve housing seated in the socket A by means of a yoke D and holding bolts D This discharge valve-housing terminates at the inner end immediately adjacent the-pump plunger in a narrow conical valve seat D, the opening through this valve seat being closed by a pointed conical or needle valve D slidable in the housing and guided therein by a series of vanes D D is a rigid spring seating this discharge valve, and D? is an oil pipe or conduit leading from the discharge valve housing to a spray nozzle :23 or member not here shown.

It will be noted that the passage leading from the pump cylinder to the discharge valve is above the discharge of the intake valve, but

still is below the highest part of the system, in this case the upper portion of the pump cylmder, so that any bubbles of gas or air which may rise up through the system will still be caught in the pump cylinder above the point at which the oil is discharged.

E is the by-pass valve housing which is contained within the socket A as is the socket itself in line with the pump cylinder. The inner end of this housing is provided with an extension E which penetrates into the pump cylinder. This extension is hollowed out in conical form as at E to conform to the shape of the conical or pointed nose of the pump plunger. The discharge from the pump cylinder through this housing takes place at the apex of the cone where a very narrow passage E is adapted to be. closed by a needle valve E-. This needle valve is carried by a reciprocable pin E projecting out through the stufling box E E is an oil discharge passage communicating with the interior of the by-pass valve housing so that any oil that member E is moved to the right as in Fig. 1

the spring IE will be compressed and the valve unseated, since the parts move in the opposite direction, and therefore will be immediately closed. The sole function of the spring E is to keep the collar E always firmly seated on the lever E unless and until the lever moves back too far and the movement of the collar is arrested by the seating of the needle valve. The purpose and operation of this spring is exactly the same as the purpose and operation of the valve springs in ordinary automobile engines, that is it keeps the parts tight, seats the valve, makes it unnecessary to have as close fits and accurate workmanship as otherwise would be necessary.

The pump cylinder is counterbored out around the pistonimmediately in line with the two right angle valve sockets. The bearing of the cylinder is fitted closely by the plunger. The need for this arrangement, is that experience shows that in the very tight fits that are used, it sometimes happened that if one of the valve housings is removed, and afterwards replaced, it may be drawn up so tight that the piston will actually bind. In order therefore, to provide clearance and still make it possible to have the pump tight this slight counterboring is adopted.

I have shown in my drawings an operative device, still many changes may be made in size, shape and arrangements of parts without departing from the spirit of my invention. The pump is designed, as has been ex: plained above, primarily to be used in connection with internal combustion engines. As designed it is expected to be associated very closely with that engine and is not itself artificially cooled. It will therefore in operation be heated by the heat generated by the engine, and since it is not cooled, it will remain heated.

A feature of great importance in the invention is the use of a single high point in the pump chamber to which the incoming liquid is drawn. The pump chamber with its associatcd passages is so shaped that in its normal flow the liquid upon entering the chamber will tend to pass to a high point in the system and will be momentarily brought comparatively to a stand still at that point. Thus the entrained air and gas is carried by the flow of the liquid to this high point and because of this movement, gravity assists in the separation of the air and gas, and because at this point the flow of liquid is momentarily stopped, gravity is enabled more completely to act further to assist in the separation. This high point is above the point of discharge to the engine cylinder so that when fuel is discharged into the engine cylinder, there is no tendency to entrain the air and gas in the fuel charge which is being discharged into the engine cylinder. The shape of the pump chamher is such, however, that in the by-passing operation the air and gas will be readily and positively entrained, and by means of the regular flow and the high speed of the flowing liquid, will be carried from the high point, off through the by-pass valve. The shape of the parts is thus arranged to co-operate n segregating and isolating the air and gas, and in holding such segregated air and gas from the fuel charge which is injected into the engine and in conducting it to the by-pass opening at the time of by-passing.

The use and operation of my invention are as follows:

The pump plunger reciprocates m time with the engine, if it is engine driven, or 1n time with the driving mechanism if an engine is not involved. As it reciprocatcs moving in a back direction, it in the usual manner sucks up into the system this oil, which passes in a relatively high velocity through the ntake valve sweeping over all parts of the 1ntake system, and since there are no dead spots or inwardly reentrant pockets, there 1s no possibility of stagnation in that system and no chancethatthe segregation of air or gas laden oil, or the formation and caging of any bubbles. Any bubbles or any gas or air laden oil will thus pass up into the pump cylinder, and since at the end of the stroke there 1s 11ttle if any turbulence such gas or air laden iii.

oil will have opportunity to rise to the top 'mediately be generated and almost immediately that pressure will be great enough to unseat the discharge valve, and the oil from beneath that part of the pump cylinder Where segregation of the lighter air or gas laden part of the oil takes place, will be discharged through the discharge valve to the spray nozzle or spray member or engine cylinder as the case may be. 5

As the pumping movement of the plunger continues the pointed end of the plunger will penetrate within the conical portion of the by-pass valve housing. At some point during this the governor or the hand of the operator or any other suitable timing or turning source will open the bypass valve. When that happens pressure will instantly drop and the discharge valve instantly close and as the pump plunger continues to reciprocate oil will be forced out ahead of the pointed piston through the by-pass valve. This arrangement of a pointed piston or plunger and pointed socket toward which it moves is provided in order to permit relatively high liquid velocities even before the end of the stroke and that together with the wiping action of the shoulder of the plunger within the pump cylinder will tend to force or drive or entrain all the lighter segregated bubbles or air or gas laden oil out through the by-pass valve. The result of this is that by each reciprocation of the plunger the system is cleared of all the segregated gas or air and there is thus no time for any appreciable quantity to be caught within the system. I

In pointing out and claiming the processes which form part of my invention, I have been compelled to name the several steps in order but it will be understood the order in which I have named them is not of the essence of the invention and in many instances the order can and perhapsshould be changed. In addition with the gravity separating the air or gas bubbles after they have been formed are entrained by the flowing current of the liquid in the system at a relatively high rate of speed and by this entrainment they are carried toward the place at which it is desired that they shall be left and segregated out as they reach that point. The arrangement of the parts is such that the facilities will decrease sothat these air bubbles will be deposited at the desired position and left there. This action takes place independent of the operation of gravity and has or may be in a sense largely supplementary to the gravity action.

I have shown in the drawings, particularly in Figures 1 and 2 clearances in the assembly of the parts. Thus the member E is shown with a clearance about its outside. This is not a clearance which is open for liquid, it is simply such a clearance as permits the in assembly to be fitted together.

It will be noted that in the design of the applicant every e-ifort has been made to reduce the clearances between the plunger, barrel and other adjacent parts to the minimum possible. The reason for this is that the air and gas laden oil which is to be disparts charged must move at high velocity during! the time of discharge in order that all bubbles which have considerable tendency to adhere to the walls of the chamber may be surely and positively swept out of the pump cham- I claim: 1. A liquid atomizing system comprising a pump chamber, a liquid supply conduit, a

suction valvetherein, a spray nozzle, a conduit between it and the pump chamber, a discharge valve' therein, a by-pass discharge passage leading from the pump chamber and a mechanically operated release valve controlling it, the conduit leading to the spray nozzle discharging from the'pump chamber at a point appreciably below the highest point thereof, a piston adapted to reciprocate in the pump chamber, having a pointed end, the

trolling it, the by-pass discharge passage leading from the pump chamber along the axis thereof, the conduit leading to the spray nozzle discharging from the pump chamber at a point appreciably below the highest point thereof, a piston adapted to reciprocate in the pump chamber, having a pointed end, the pump chamber terminating in a conical portion substantially the same size and shape as the pointed end of the plunger, the by-pass discharge passage leading from the apex of such conical portion.

3. A pump comprising a cylindrical pumping chamber,'a plunger of substantially the same cross section thereas and having a conical nose, the chamber terminating in a conical pocket into which the nose of the plunger is adapted to fit, intake and dischargeports in the cylindrical part of the chamber and a second discharge port at'the apex of said pocket.

4. A pump comprising a cylindrical pumping chamber, a plunger of substantially the same cross section thereas and having a conical nose, the chamber terminating in a conical pocket into which the nose of the plunger is adapted to fit, intake and dischar e ports in the cylindrical part of the cham er, and a second discharge port at the apex of said pocket, there being only suflicient clearance between the wall of the chamberv and the plunger about the intake and discharge ports to prevent binding of the plunger.

5. A pump comprising a cylindrical pumping chamber, a plunger of substantially the same cross section thereas and having a conical lose, the chamber terminating in a conical pocket into which the nose of the plunger is adapted to fit, intake and dischar e ports in the cylindrical part of the cham er and a second discharge port at the apex of said pocket, the end of the chamber being closed by a separate plug, which is cut away to form the pocket into which the plunger penetrates.

6. In a liquid pressure system a combined settling tank and pump cylinder located in the high point thereof, intake and discharge ports in thewalls thereof below the high point, a pump plunger mounted for reciprocation in the cylinder and'an air and liquid discharge port arranged in 'one end of the cylinder axially in. line with the pump plunger, the piston being of substantially the same diameter as the cylinder and being adapted to substantially fill the cylinder at the inner end of .its stroke. 7

7. In a liquid pressure system a combined settling tank and pump cylinder located in the high point thereof, intake and discharge ports in the walls thereof below the high point, a pump plunger mounted for reciprocation in the. cylinder and an air and liquid discharge port arranged in one end of the cylinder axially in line with the pump plunger, the pump plunger having a conical nose, the axial discharge port being at the apex of a conical pocket in which said nose isadapted to fit.

8. In a liquid pressure system a combined settling tank and pump cylinder located in the high point thereof, intake and discharge ports -in the walls thereof below the high point, a pump plunger mounted for reciprocation in the cylinder and an air and liquid discharge port arranged in one end of the cylinder axially in line with the pump plunger. the piston being of substantially the same diameter as the cylinder and being adapted to substantially fill the cylinder at thinner end of its stroke, the pump plunger having a conical nose, the axial discharge port being at the apex of a conical pocket in which said nose is adapted to fit.

9. In a liquid atomizing system, comprising a pump, a discharge port and a series of conduits, means for segregating the gas and air included in the liquid at a high point in the system, means for discharging'p part of the li iiid through the spray nozzleand indepen ent gineans for separately expelling the segregated gas and. air from the system the pump comprising a plunger having a pointed nose, a pocket in the end of the pump chamber into which said nose is adapted to penetrate, the discharge forthe segregated material being from the apex ofsuch pocket.

10. In a liquid atomizing system comprising a pump, a discharge port and a series of conduits, means for segregating'the gas and air included in the liquid at a high point in pressure actuated valve controlling t 1e spray nozzle and a mechanically controlled valve controlling such separate discharge of the segregated material, the pump comprising a plunger. having a pointed nose, a pocket in the end of the pump chamber into which said .nose is adapted to penetrate, the discharge for the segregated material being from the apex of such pocket.

11. In a liquid atomizing system comprising a pump, a discharge port and a series of conduits, means for segregating the gas and air included in the liquid at a high point in the system, means fordischarging a part of the liquid through the spray nozzle and independent means for separately expelling the segregated gas and air from the system, a pressure actuated valve controlling the spray nozzle and a mechanically controlled valve controllin such separate discharge of the segregated material, the pressure actuated valve being set to close immediately upon opening of the mechanically controlled! valve, the pump comprising a plunger having a pointed nose, a pocket in the end of the pump chamber into which said nose is adapted to penetrate, the discharge for the segregated 'material being from theapex of such pocket.

12. In a liquid atomizing system, comprising a pump, a discharge port and a series of conduits, means for'segregating the gas and air included in the liquid at a high point in the system, means for discharging a part of the liquid through the spray nozzle and independent means for separately expelling the nose is adapted to penetrate, the discharge for the segregated material being from the 12 apex of such pocket.

13. In a liquid atomizing system comprising a pump, a discharge port and 'a'series of conduits, means for segregatin the gas and f air included in the liquid at a igh point in the system, means for discharging a part of pendent means-for separately expelling the segregated gas and air from the s stem, a

I controllin pressure actuatedvalve controlling t e spray nozzle and a mechanically controlled valve such separate discharge of the segregate cated in the wall of the pump chamber below the 'highpoint thereof, the discharge for the segregated air and'oil being located in the end of the cylinder on the axis thereof, the pump comprlsing a plunger having a pointed nose, a pocket in the end of the pump chamber, into which said nose is adapted to penetrate, the discharge for the segregated material being'from the apex of such pocket.

14. In a liquid atomizing system compris ing a pump, a discharge port and a series of conduits, means. for segregating the gas and air included in the liquid at a high point in the system, means for discharging a part of the liquid through the, spray nozzle and material, the communication between the pump and the spray nozzle being 10- independent means for separately expelling the segregated gas and air from the system, a pressure actuated valve controlling the spray nozzle and a mechanically controlled valve controlling such separate discharge of the segregated material, the pressure rotated valve being set to close immediately upon opening of the mechanically controlled valve, the communication between the pump and the spray nozzle being located in the Wall of the pump chamber, below the high point thereof, the discharge forthe segregated air and oil being located in the end of the cylinder on the axis thereof, the pump" comprising a plunger having a pointed nose, a pocket in the end of the pump chamber, into which said nose is adapted to penetrate, the discharge for the segregated material being from the apex of such pocket.

. Signed at Chicago, county of Cook and State of Illinois, this 29 day of November 1920. PHILIP LANE SCOTT.

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