US1921816A - Eccentric driven high pressure pump - Google Patents

Description

Aug. 8, 1933. w. E. GOLDSBORO UGH 1,921,816

ECCENTRIC DRIVEN HIGH PRESSURE PUMP Filed May 51, 1929 3 Sheeii$-Sheet 1 Snow/hm a. GoLDsBoRoueH Aug. 8, 1933. w. E, GOLDSBOROUGH 5 I ECCENTRIC DRIVEN HIGH PRESSURE PUMP Y Filed May 31, 1929 s Sheets-sheaf 2 hvamboz WlNDER E. eowssonoucm 331 hi elf/01m;

Aug. 8, 1933. w. E. GOLDSBOROUGH 1,921,816 7 ECCENTRIC DRIVEN HIGH PRESSURE PUMP Filed May 31, 1929 -s Sheets-Sheet s gvwemtoz @51 1115 a t tome Patented Aug. 8, 1933 UNITED STATES PATENT OFFICE ECCENTRIC DRIVEN HIGH PRESSURE PUMP Winder E. Goldsbcrough, South Norwalk, Conn, assignor to Doherty Research Company, New York, N. 51., a Corporation of Delaware Application May 31, 1929. Serial No. 367,242

5 Claims. (ill. lug-4:2

This invention relates to pumps, more particularly to pumps designed to force liquid under high pressures through a fine orifice or nozzle for the purpose of atomizing the same.

It is among the objects of this invention to provide a pump which shall be of simple, compact and rugged construction, durable and efficient in operation, and capable of supplying liquid at high pressures without transmitting severe shocks to the actuating mechanism.

In many industrial processes, it is desirable to highly atomize a liquid for the purpose of altering it either chemically or physically, or for the purpose of ,obtaining a high degree of comminution or atomization. It. is also desirable in connection with many such processes to accurately measure the quantity of liquidatomized with each repetition of the process or cycle. For example, in engines of the type commonly known as solid injection engines, it is the practice to supply fuel to the working cylinder when the piston thereof is at or near its upper dead center position. In order to obtain proper atomization of the fuel without the aid .of compressed atomizing air it is desired that the pressure of the fuel be as high as practicable, pressures of from 2000 to 16,000 pounds per square inch having been tried. The quantity of fuel is varied in accordance with the load, or the will of the operator, and the timing of the injection is varied in a manner analogous to the variation of the spark in an Otto cycle engine. In such enginesthe control of the quantity of fuel supplied and also the timing of the injection present difficult, vital problems because the quantity of fuel comprising the fuel charge for any one cycle is small and a variation of but a few drops in the case of a large engine or the fraction of a drop in the case of a small engine seriously affects the efficiency. The same conditions are met with in certain types of combustion turbines and in other relations.

It is one of the objects of this invention to provide a pump capable of accurately measuring oil or other liquid under varying conditions and supplying the same under the desired pressure to the point at which it is to be atomized in properly timed relation to the cyclic occurrences in the process in connection with which it is used.

It is a further object of this invention to avoid working against high pressure when varying the quantity of fluid supplied by the pump or the timing of its discharge. To this end, it is a feature of this invention that both of these variations are effected by means of a single cylindrical member surrounding a pump plunger, the move ments of which are not affected by the pressure in the pump chamber. Longitudinal movement of the cylindrical member is preferably used to vary the timing, while rotation of the cylindrical member about the plunger is preferably used to vary the quantity.

In the engine of the type referred to, it has heretofore been impossible to change from the grade of fuel for which the pump was designed to another grade of entirely different calorific value. It thus occurs when the preferred fuel is unavailable, or another grade becomes more plentiful, that the old pump designed to function upon the old fuel is not suitable because the quantity of the two fuels required for the same power output is greatly different and beyond the ordinary range of quantity adjustment ordinarily provided.

It is one of the objects of this invention to provide a construction in which a major adjustment in capacity can be made other than that provided for variations in load. To this end, it is one of the features of this invention to provide a plurality of interchangeable pump barrels and c0- acting plungers so that great changes in capacity of the pump may be made with little delay.

These and other objects of the invention will be more particularly described in connection with the accompanying drawings, in which:

Fig. 1 is a longitudinal section through one form of pump constructed in accordance with this invention, parts being sho .l in side elevation;

Fig. 2 is a section taken on the line 2-2 of Fig. 1, parts being shown in side elevation;

Fig. 3 is a section taken on the line 33 of Fig. 1, parts being shown in side elevation;

Fig. 4 is a top plan view'showing the construction of the groove in the control member;

Fig. 5 is a longitudinal section through a pump illustrating a modified form of construction;

Fig. 6 is a section taken on the line 6-6 of Fig. 5;

Fig. 7 is a diagrammatic view illustrating the construction of the control member used in connection with the pump shown in Fig. 5; and showing the same as it would appear if opened and rolled out flat. v

Fig. 8 illustrates the use of interchangeable plungers and liners for the purpose of altering the capacity of the pump.

Referring particularly to Fig. 1, 10 designates a housing forming the main body of the pump and having a bore 12 of varying diameter extending therethrough. A pump barrel or liner 14 is inserted in one end of the bore 12 and is held against a shoulder 16, formed by an enlargement of said bore, by means of the bushing 18.

A double-acting piston 20 formed of a rod 22 and an enlarged portion 26 integral with said rod is reciprocative in bore 12. The enlarged portion 26 is shouldered at 28 and forms with the housing 10 an annular chamber 30 between the shoulder 28 and a shoulder 32 formed in the hous-.

ing 10 by an enlargement of the bore 12. The enlarged portion 26 has a large bore 84 extending partially therethrough and connecting with a smaller bore 36. A plunger 38 is removably inserted in the large bore 34 and is adapted to slide with a close fit in the pump barrel 14 upon reciprocation of the rod 22. The plunger member 38 has a bore 40 extending longitudinally therethrough and which is adapted to form with a rod 42 an annular channel forming a free passage for the flow of fuel through the plunger. The rod 42 is provided with an external screw thread at one end adapted to screw into the internal screw thread of bushing 44 to retain the plunger member 38 in the large bore 34.

The member 20 is provided with a bore 46 extending diametrically therethrough and adapted to contain a housing 46 of a valve-56. An externally threaded bushing 52 retains the valve housing 48 upon a shoulder 54 formed by an enlarged portion of the bore 46. The valve 50 is provided with a seat 55 adapted to coact with a seat 56 in' a removable bushing 58 in the opposite end of the bore 46. A stem 60 of the valve 56 extends through the bushing 58 and projects through the piston 20 to slide upon the cylindrical wall of the pump. This portion of the pump wall in this instance is formed by a semi-cylindrical control member 62 having a groove 66 extending along the surface thereof as may be more particularly seen in connection with Fig. 4.

In order to regulate the quantity of fuel supplied to the engine and also the timing of the injection into the engine, an adjusting member 64 is provided surrounding the rod 22 and closing one end of the bore 12 which forms the pump cylinder. The member v6-4 is adapted to be roated about the rod 22 to shift the member 62 ubntaining the groove 66 angularly about the piston 20. The mechanism for effecting this adjustment may be more particularly seen in Fig. 2 in which a split bushing 68- is rigidly connected by meansof a screwbolt 70 with a short sleeve '72 surrounding the adjusting member 64. The

short sleeve .72 is slidable relative to the adjust-' ing member 64 but angular movements of the same are transmitted to the adjustment member by means of a key 74. The split bushing 68 is provided with an arm or extension '76 adapted to be connected by means of a ball and socket joint indicated at 78 to a rod 80 which may be manually or governor controlled as desired.

80 are transmitted by the mechanism just described into the angular movements of the control member 64. Such movements of the control member rotate the semi-cylindrical member 62 relative to the piston 20, bringing a wider or a narrower portion of the groove 66 depicted in Fig. 4 adjacent the end of the valve stem 60 of the valve 50. Referring particularly to Fig. 4 it will be seen that the groove 66 in the semicylindrical member 62 is formed with one of its edges 82 forming a straight line lying in a single transverse plane taken through the axis of the pump plunger. The opposite edge 84 of the groove 66 is curved away from the edge 62 forming a continually widening depression.

The semi-cylindrical member 62 is preferably formed separately from its adjusting member or sleeve 64, and removably connected thereto by a screw bolt 63. It may readily be seen however that the member 62 might be an integral part of sleeve 64.

Liquid is supplied to a suction chamber 86 formed in the rear end of the pump by means of a supply line 88 which line leads to any convenient source of supply which may be under any desired head, or where conditions permit may even be below the pump and drawn up thereto by suction in the suction chamber 86 In the operation of the device thus far de scribed, liquid isdrawn into the suction chamber 86, under any desired pressure head upon movement of the piston 20 to the right by means oi eccentric 92. Upon the return movement of the piston 20 to the left, the liquid in the suction chamber 86 is forced by the piston through the space 94 between the grooved member 62 and the said piston, thence through valve 50, the passage 36, the annular channel surrounding rod 42 in the removable plunger member .38 to the pressure chamber 98. The displacement of the enlarged portion 26 of the piston 20 being greater than the displacement of the removable plunger member 38, fuel is displaced during the movement 'of the plunger to the left faster than can be accommodated in the pressure chamber 98. In order to accommodate this difierence, an additional chamber is provided which is formed between the inner edge of the pump barrel 14 and the shouldered portion 102 of plunger 38. The displacement in chamber 100 together with displacement in the pressure chamber 98 are made exactly equal to the displacement of the enlarged. portion 26 of piston 20 in the suction chamber 86, so that upon movement of piston 20 to the left, the decrease in the volume of suction chamber 86 is exactly equal to the increase in volume in the two chambers 98 and 100. Suction chamber 86 is' connected with chamber 100 by means of continually open passages 104 and 106, provided in the housing member 10, so that upon movement of the plunger to the left fuel or other liquid is displaced from chamber 86 into both chambers 98 and 100, without any material increase in pressure in suction chamber 86, or a decided decrease in pressure in chamber 98 or chamber 100. 7

Assuming that the piston 20 has been moved as far as possible to the left by eccentric 92, further rotation of the eccentric moves the piston to the right. During the early portion of this movement, the stem 60 of the valve 50 rests upon the plane surface 67 of the grooved member 62, retaining said valve in open position so that the pressure chamber 98 is in open communication with the suction chamber 86. Therefore the fuel displaced in chamber 98 passes to chamber 86 without a material increase in pressure. At about the mid-stroke of the piston .20, that is, while the same is being driven at its highest velocity.by means of the eccentric 92, the stem 60 of the valve 50 slides over the edge 82 of groove 66, so that the valve 50 is closed. Pressure in the chamber 98 at once builds up to a high value overcoming the resistance of the nozzle so that a charge of liquid is injected into the combustion chamber or other device to which the nozzle is connected. During the interval in which the valve 50 is closed and liquid is being displaced from the chamber 98 through a nozzle 108, fuel is drawn into the chamber 86 from the main supply. This interval is very brief relative to the entire stroke of'the piston 20, since the stem 60 of the valve 50 soon contacts with the opposite edge 84 of the groove 66, and is opened thereby. The pressure in chamber 98 is at once released, and further displacement of the plunger in this chamber merely forces fuel through the piston passages and past the valve 50 into the chamber 86. The pressure in chamber 98 is thus abruptly reduced permitting a sharp termination of the injection into the engine cylinder or other mechanism whereby dripping at the nozzle is prevented and all the liquid is efliciently atomized. Upon movement of the piston 20 to the left, the valve 50 is held open both positively by reason of the fact that the stem 60 of the valve rests upon the surface 6'7 and also because of the flow of liquid during this period from the chamber 86 to the chamber 98. Thus when the valve stem 60 crosses the groove 66 upon movement of the piston 20 in this direction, the valve does not close as it does when traversing the groove in the opposite direction, due to'the pressure of the fuel thereon, so that. a negative pressure is at no time created in the chamber 98 during the operation of the pump.

Changes in the timing of the pump relative to its driving mechanism are effected by longitudinal movements of the grooved member 62 relative to the piston 20. The elements for efiecting this variation consist of a collar 110 flexibly connected by means of pins 112 or equivalent elements, with an annular groove 114 in the control member 64, so that member 64 is free to rotate relative to collar 110, the longitudinal movements of the one being transmitted to the other. The collar 110 has an internally screw threaded portion 116 which is adapted to coact with an externally screw threaded portion 118 upon a sleeve or bushing 120 which is keyed to the rod 22 of the pump by key 122 in a manner preventing angular movements of said bushing relative to the rod while permitting relative longitudinal movements thereof. The bushing 120 is rigidly fixed by means of projection 124 to the frame 126 of the engine. By rotating collar 110 about the bushing 120 the collar is screwed to the right or to the left, and its longitudinal movement transmitted through the pins 112 to the control member 64, which in turn draws or pushes the grooved member 62 to the right or left. Thus the stem 60 of the valve 50 traverses the groove 66 earlier or later in the stroke of the piston. Since the eccentric shaft 128 is driven by and in unison with the main shaft of the engine or other machine, the point in its cycle at which the valve 50 traverses the groove 66 is thereby altered to alter the time of injection. A lock nut 130'is provided adjacent the collar 110 to insure that the timing mechanism will not be altered due to the operation of the pump.

Fig. 5 illustrates the invention in a slightly modified form. In this construction all the parts are similar and analogous to those shown in Fig. 1 except that instead of the grooved member 62 coacting with a valve carried by the piston, a-

collar 132 is provided with openings 134 and 136, which leave a strip of metal 138 therebetween. The formation of this strip closely corresponds to the conformation of the groove shown in the grooved member 62. The plunger is provided with. a pair of valveless passages 140 extending diametrically therethroughi It will be seen that when these passages are adjacent the openings 134 and 136, the supply chamber 142 will be in open conmiunication with the pressure chamber (not shown) in a manner analogous to the communication between chambers 86 and 98, in the previously described construction when valve 50 is raised above the surface of seat 56. When the passages 140 are adjacent the metal strips 138 the passage is closed thereby the same as passage 46 is closed by valve 50 when the valve is traversing the groove 66. In other respects the operation of this construction is identical with that of the form previously described.

It will be seen that thefirst described construction is more to be desired when the pressures to be attained are extremely high, that is approaching the limit of those mentioned, while the last described construction is suitable in case the pressures required are, while high, not so extreme as to cause leakage.

It will be seen that both constructions described provide a pump in which both the quantity of liquid supplied and the timing of such supply may be separately and individually altered by movements of a single member.

It will be understood that while there has been hereindescribed constructions in which the control member is moved angularly or longitudinally of the plunger to eifect the desired variations, any movement of one of these members relative to the other may be used to eifect the same end. That is, the piston 20 might be ro- .tated while the control member remains staor liquids of widely varying composition. The

,plunger being actuated preferably by an eccentric, provides a simple harmonious motion of the reciprocating parts while the point of injection at all times corresponds fairly closely to the maximum speed of the plunger, whereby high pressures are rapidly attained at the instant desired, yet without severe shock to the actuating mechanism because the parts are already moving at their highest velocity in the desired direction, and it is not necessary to overcome both inertia of the reciprocating parts and the pressure of the liquid at the same time.

While but two forms of construction of fuel pumps in accordance with this invention have been described, it will be apparent to those skilled in the art that many alterations and modifications of the members herein disclosed are practicable.

While the invention is particularly useful in connection with internal combustion engines and combustion turbines it will be readily appreciated that the same is useful in many other positions.

Having thus described the invention what is claimed as new is:

1. In a pump, a cylinder, 9. plunger reciprocative therein, a sleeve surrounding said plunger having a groove in the surface thereof, a passage in the wall of the plunger adapted to cross said groove in the course ofthe reciprocation of said plunger, means whereby only that portion of the plunger stroke during which said passage traverses said groove is effective in forcing fluid from said pump, and means whereby the width of the groove traversed by said passage is varied to vary the quantity of fluid forced from said cylinder upon each stroke of said plunger.

2. A pump for supplying fuel having a suction chamber and a pressure chamber, a plunger reciprocative in said pressure chamber, means to displace fuel from said suction chamber to said pressure chamber during the suction stroke of said plunger at a rate which is at all times equal to the rate of evacuation of said plunger.

3. A pump for supplying fuel from a source of supply, including a cylinder forming at one end a supply chamber in open communication with said source of supply, and at its opposite end a pressure chamber, a piston reciprocative in'said cylinder, passaged means extending from one end of said cylinder to the other whereby fuel passes from the supply chamber of said cylinder into said pressure chamber during the outward movement of said piston at a rate which is at all times equal to the evacuation of the piston in said pressure chamber.

4. A fuel pump having a housing, a pump barrel removably inserted in said housing, a piston rod extending through said housing and connected with a plunger reciprocative therein, a supply chamber on the piston rod side of said plunger, a plurality of chambers on the opposite side of said plunger communicable therewith, the effective area of the plunger on the piston rod side of said plunger being equal to the sum of the eifective areas upon the opposite side of said plunger.

5. A pump having a cylinder, a passaged plunger reciprocative in said cylinder, a valve extending diametrically through said plunger, and positive means to actuate said valve in the course of the reciprocation of said plunger.

6. A pump having a cylinder, a passaged plunger reciprocative in said cylinder, a valve extending diametrically through said plunger and positive means to actuate said valve at a variable point in the course of the reciprocation of the plunger.

WINDER E. GOLDSE-OROUGH.

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