US2095915A - Fuel pump - Google Patents

Description

Oct. 12, 1937. L. F. BURGER 2,095,915

FUEL PUMP Filed m 5, 1935 4 Sheets-Sheet 1 Oct. 12, 1937. L. F, BURGER 2,095,915

FUEL PUMP Filed July 5, 1935 4 Sheets-Sheet 2 1937. F. BURG ER 2,095,915

FUEL PUMP Filed July 5, 1935' 4 Sheets-Sheet a r7 61 L r L. F. BURGER Oct. 12, 1937.

FUEL PUMP Filed July 5, 1935 4 Sheets-Sheet 4 Patented Oct. 12, 1937 UNITED STATES PATENT OFFICE FUEL PUMP Leopold F. Burger, Riverside, Ill., assignor to International Harvester Company, a corporation of New Jersey Application July 5, 1935, Serial No. 30,001

1 Claim.

- complished by a centrifugal device operated by the engine. Due to the desirability of placing such a device, usually termed a governor, as close to the means which it regulates as possible, unit constructions have been used, in which the governor is mounted in the pump casing directly on the pump shaft. It is to a construction of this type that the present inventionrelates.

In the operation ofcompression ignition enone method of overcoming this difficulty, such engines have been provided with means for lowering the compression and starting with volatile fuel and spark ignition, such as shown in United States Patent No. 1,225,295. Means have also been developed for automatically shifting from the Otto cycle to the Diesel cycle after a predetermined numberv of revolutions, as disclosed and claimed in the pending application of Edward A. Johnston Serial No. 557,997, filed August 19, 1931. In the control unit of the present invention, mechanism has been incorporated in the pump casing for operating acontrol member for shifting the cycle of operation. of the engine or for other purposes for which it may be found useful in the operation of an engine.

The principal object of the present invention is to provide an improved control'unit for solid injection engines. A more specific object is the provision of a balanced fuel supply governor for solid injection pumps. Another object is the incorporation in a unitary structure of a pump, a control unit therefor, and a control unit for regulating or determining another function of engine operation. These objects and others, which will be apparent from the following detailed description to follow, are accomplished by a device as. shown in the drawings, in which:

Figure 1 is a vertical section takenjlongitudinally of a pump and control unit incorporating the invention, with certain portions broker '=-way in section better .to show certain elements, as for example the pump control shaft shown by a second vertical section parallel to the. first main section;

Figure 2 is a transverse vertical section of the unit shown in Figure 1;

Figure 3 is an elevational view showing a trip 'gines, starting constitutes a problem whenever, as, in the case of a tractor, manual effort must be relied upon to turn the engine for starting. As-

unit particularly adapted for actuation by the control member shown in Figure 2;

Figure 4 is a. section taken on the line 2-4 of Figure 2 Figure 51s a. plan view of the rocker arms. for operating the pump ,plungers, the bearings being shown in section;

Figure 6 is a plan view of the rocker arms for operating the by-pass valves, the bearings being shown in section, and a portion of the control shaft mechanism;

Figure 7 is an end elevation of the unit shown in Figure l-with the cover removed; and,

Figure 8 is a vertical transverse section taken on the'line a-a ,ofFigure 1.

As illustrated, the pump and control unit are housed in a casingl'lll divided by a vertical partition ll into two compartments. An extension housing I2, secured to an open end of the casing, provides additional space for the governor mechanism. A cover plate l3 closes the open'end of the housing l2. Above the casing ID, a cylinder block I4 is secured, in which the pump cylinders are mounted. A head I5 is mounted over the block I l and includes, formed integrally therewith, a pump casing I6,

A pump shaft l'l provided with means for conheating with an engine drive mechanism extends longitudinally of the casing I0, being provided with suitable bearings, one of which is illustrated by the ball bearing assembly l8 mounted in the partition H. A plurality of spaced cams l0 on the shaft I! operate rocker arms 20 pivotally mounted on a. shaft 2|. Said rocker ar'ms engage tappets 22, slidably and non-rotatably mounted in a portion of the casing l0. Said tappets operate the pump plungers 23.

Rocker arms 24 pivotally mounted on eccentrics formed on a shaft 25 are provided with extensions seated in slots 26 formed in the tappets 1 22. The rocker arms 24 are provided on their upper faces with recesses, in which tappets 21 are seated. Said tappets 21 operate by-pass valves, the stems 28 of which are shown in alignment with the tappets 21.

The pump as illustrated and described up to this point is of a'conventional construction now in wide commercial use. Adjustment of the shaft 25 alters. the time of by-pass, thereby controlling the effective stroke of the pump plungers and the charges of fuel delivered thereby.

The shaft I1 is provided with a carrier 29 on which governor weights 30 are pivoted on diametrically located, parallel axes. Said weights are substantially arcuate in shape, fitting around mitted to a sleeve 35 concentric with respect to the sleeve 34 and piloted on said sleeve. The sleeve 35 is slidably fitted into a cup-like member 36, which is in turn slidably fitted in a bore formed in the housing l2. A compression spring *31 abutting the inside 'of themember 34 abuts a pilot member 38 ,through which pressure is transmitted in an axial direction on a flange formed on the sleeve 35. It will be understood that by this construction the spring 31 opposes the force developed by centrifugal action on the weights 30.

As a stationary limiting adjustment for the member 36, nuts 36 are threaded on a stud secured to a portion of the housing I2. One of said nuts overlaps the head portion of the member 36, (as shown in Figure 7), thereby limiting outward movement of said member.

A bell crank member 39 is pivotally mounted on a pivot pin 40 extending transversely of the axis of the shaft l1 above said shaft. Said member is provided withspaced, downwardly extending, lever arms 4|, which carry members 42 positioned between spaced flanges 43 on the sleeve 35. By means of this construction, reciprocating movement of the sleeve 35- oscillates the bell crank member 39.

The member 39 also carries an upwardly extending lever arm 44, which carries means for engagingspaced flanges 45 mounted on a shaft 46. Said shaft is mounted for reciprocation on an axis parallel to the axis of the pump shaft l1. At its inner end, the shaft 46 is provided with a threaded adjusting member 41, by which the effective compression of a, spring 48 may be regulated. Said spring abuts a stop carried by a portion of the casing in. At its other end the shaft 46 abuts one end ofa rocker member 49 rigidly secured to a transverse shaft 56 pivotally with the rocker arm 49, carries an adjusting le- I ver 5| at one end, through which a threaded adjusting member 52 extends. By the adjustment of said member the maximum angular position of the rocker member, acting to increase compression on the spring 31, is limited. Outside the casing, the shaft 56 carries a lever 53 for manual operation to effect speed change of the engine by control of the fuel supplied thereto.

The bell crank member -39 carries integral therewith an extension 54 formed as a. sector of a gem, by which rotary motion is transmitted to a gear 55 non-rotatably mounted on the pump control shaft 25.

Intermediate its end the shaft I1 is provided with a worm wheel 56 positioned to engage and drive a worm gear 51 mounted on a vertical shaft 58. Said shaft. is carried by the casing I 0 and extends upwardly, as shown in Figure 2, above 'the broken away portion to drive the pump in the casing I 6. This part of the mechanism has not been shown, as it is not involved in the present invention. The shaft 58 carries a worm gear 59, which drives a worm wheel 60 on a transverse shaft 6| carried by the casing I 0. Said shaft is provided with an eccentric 62, on which a ratchet member/63 is pivotally mounted. Said ratchet member is spring pressed by a member 64 mounted in a bore formed in a portion of the casing I0 into engagement with a toothed ratchet member 65. A spring pressed latch 65' holds the ratchet member 65 against rotation in an angular direction opposite to the direction in which it is rotated by the ratchet member 63. The member 65 is rigidly carried by a shaft 66, rotatably mounted in the casing Ill and extending outside the casing for manual operation to set the ratchet member 65.

A cam 61 on the shaft 66 is positioned to engage a plunger 68. Said plunger operates a push rod 69, the lower end of which is shown in Figure 4 and the uper end of which is shown best in Figure 2.

Said shaft may control any desired function of engine operation, preferably a control for shifting from Otto'cycle to Diesel cycle, as disclosed and claimed in the Johnston application previously referred to.

The operation of the trip mechanism will be clear from the description of the parts. The ratchet member 63, continuously driven at a reduced speed from the shaft l1, engages the notches of the ratchet member 65, slowly rotating said member. By means of the hand adjustment provided by the shaft 66 extending outside the casing, the ratchet member 65 may be set with the cam 61 in any desired position. For example, said cam may be set at such an angular position with respect to the plunger 68 that 600 revolutions of the engine will be required to lift the push rod 69 into tripping position with respect to the member 12. The cam may be set at any location from its maximum to a position where the latch will be tripped by a very few engine revolutions. This mechanism is particularly useful in connection with shifting from Otto to Diesel cycle, as previously pointed out. It is a unique construction in that it is combined with a fuel pump in a unit construction.

The operation of the governor for shifting the control shaft 25 and varying the effective length of the pump stroke thereby is conventional in commercial pumps. Applicant, however, has provided an improved balancing means and limiting stops to improve the functioning of the pump, particularly to reduce what is known in governor action as hunting? or surging. The regulating spring 48, which opposes action of the spring 31, has the function of a secondary control, which can be accurately adjusted to obtain a more uniform governor action. To provide means for varying the range within which the governor operating means may be connected to the lever 53. Referring to Figure 1, manual operation of the shaft 50 in a counter-clockwise direction moves the rocker member 49, which is carried by the shaft, in the same angular direction. 'The lower end of the member 49 abuts the head por tion of the cup member 36. Movement of this v member to the right compresses the spring 31 abuts the stop formed by the nuts 36'. determines the minimum speed at which full and in effect increases the speed of the engine, as a higher speed is required for the governor weights to compress the spring and to move the bell crank member 39 for effecting a reduction in fuel supply. To. limit the increase in speed which can be given to the engine by the manual adjustment, an adjusting stop 52 is provided on a lever 5| carried by the shaft 50. When the stop 52 abuts the end wall of the housing, as shown in Figure 7, the spring cannot be further compressed and the speed of the engine cannot be increased- It is to be understood that, at any manual setting, thegovernor is effective to maintain the speed for that setting as predetermined by the governor construction and the compression rate of the spring 31 and the auxiliary spring 48.

1, to reduce the speed of the engine, the cup meniber 36 moves outwardly to the left until it This stop governor action is available. For further decreases in speed the member 49 is manually-rotated in a clockwise direction to move the shaft 06 to the right, thereby rocking the bell crank member 39 and rotating the control shaft 25 to reduce the amount of fuel injection. By this manual means the injection of fuel may be reduced to a minimum, or to zero, for stopping the engine, if the by-pass valves are constructed for a zero amount of injection.

By the means above set forth, a governor is provided which is effective to maintain a given speed at any of a wide range of settings. The

manual control for changing the effective range also incorporates means for manually reducing the fuel supply for idling or for stopping the engine.

It is to be understood that applicant has shown and described only certain preferred constructions illustrating the principles of his improved pump and control unit and that lie-claims of the pump, centrifugal governor weights mounted on the pump shaft, a governor reciprocated member positioned in alignment withthe pump shaft and adapted to be operated by the governor weights, a spring positioned to abut a portion of said member for counteracting the force of the governor weights, fixed abutment means for adjusting the pressure on said spring, a double' bell crank mounted on an axis transverse to the axis of the pump shaft, a lever arm on said crank connected to the governor reciprocated member, a lever connected to the bell crank and operatively connected to. the pump control member, a second lever arm carried by the bell crank, a control member'operatively connected to said crank for reciprocation thereby, a rocker, arm mounted on a shaft transverse to the axis of the pump shaft having an arm engaged by one end of said control member, an adjustable stop carried by said rocker arm, and manually operable means for operating saidrocker arm.

LEOPOLD F. BURGER.

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