US1222148A - Variable-delivery fuel-pump for internal-combustion engines. - Google Patents

Description

. I. A. SEYMOUR. VARIABLE DELIVERY FUEL PUMP FOR INTERNAL COMBUSTION ENGINES.

APPLICATION FILED SEPT. 30, I914.

, Patented Apr.10 ,1917.

2 SHEETS-SHEET I.

J. A. SEYMOUR.

VARIABLE DELIVERY FUEL PUMP FOR INTERNAL COMBUSTION ENGINES.

APPLICATION man SEPT. 30. 19m. 7 1,222, a Patented Apr. 10, 1917.

2 SHEETS-SHEET 2.

aeearae.

James a. snmoua, or AUBURN, new rear.

VABIABLE-DEIQIVEBY FUEL-PUMP FOR HTTEENAL-COM'EISTTON ENGHIEfi Specification of Letters Patent Patented Apr. 110, 119%,

Application filed September 30, 1914. Serial No. 864,222.

Delivery Fuel-Pumps for Internal-Combustion Engines, of which the following is a clear, full, and exact description.

This invention relates to a method of controlling the speed of internal combustion engines using liquid fuel by means of'a variable delivery fuel pump for feeding said fuel in variable quantities to such engines, the speed of the engine being automatically regulated by a centrifugal governor controlling-by suitable mechanism the amount of oil actually fed to the engine at each stroke of the fuel feed pump.

In internal combustion engines of this character, the oil or liquid fuel is usually introduced into the combustion chamber from an atomizing chamber containing air under pressure sometimes as high as 1000 pounds or more per s uare inch, and the fuel delivery pump 0 the present invention is designed to work against this high pressure.

The principal objectof my invention is to avoid the complicated mechanisms of other existing systems, and permit the use of a shaft governor, a movable eccentric actuating the pump plunger, and a simple, direct connecting mechanism between governor and movable eccentric, arranged so that the eccentricity of the eccentric, and consequently stroke of pump plunger, is directly controlled by the action of the governor, the governor, movable eccentric, and connecting mechanism all being compactly mounted togetherupon the governor shaft and revolving with it.

In my invention I employ in connection with the other features just mentioned a connecting train of mechanism between the governor and the eccentric driving the fuel pump plunger of such a character that forces may be eficiently transmitted from the governor to the eccentric for controlling the stroke of the latter, but that this train of a mechanism will not transmit forces backward from the pump plunger to the governor weights, or at least do it so inefliciently that the effective disturbing effect upon the action of the governor, due to the heavy reaction on the ump plunger, will be so diminished that it will not substantially interfere with the proper action of the governor.

Yarious other advantages and uses of my invention will become apparent from'the following specification and from the drawings which show the preferred embodiment thereof.

In the drawings, Figure 1 is a portion of the governor shaft showing partly in elevation and partly in section the complete mechanism as it would appear during normal operation with the governor weights intermediate their extreme positions;

Fig. 2 is a detail plan of the driving mechanism for the pump;

Fig. 3 is a detail plan of the governor, said Figs. 2 and 3 showing the position of the parts when the centrifugal weights are in their innermost position which they occupy when the engine is at rest.

Referring more particularly to the'drawings, S is the governor shaft for the engine and has mounted thereon the usual form of centrifugal shaft governor. The governor shaft may be the main shaft of the engine, or some shaft driven at such a fixedspeed ratio to it, that fuel will always be fedto the atomizer the same integral number of times per working cycle. This governor comprises the frame A, A fixed to the shaft by keys K K and having outwardly extending arms F and F for supporting one or more centrifugal weights C. The weights 0, C are pivoted between the arms F and F on cross-rods P P as shown in Figs. 1 and 3, and springs G, G, connected at one end to the weights 0, C at g, g and at the other end to the fixed frame at g 9?, normally oppose the tendency of the centrifugal weights to fly out away from the shaft by reason of their centrifugal force.

The pump consists of the usual casing M having pump plunger P working through suitable packing in 'a pump chamber thereof and arranged to draw in oil through inlet 1 and inlet valve if and deliver through outlet valve D and outlet pipe D, for being fed into the engine.

The pump is preferably driven directly from the" governor shaft by the following arrangement: Keyed upon the shaft S by key K is a fixed eccentric B; and revolubly mounted on this fixed eccentric B as a hearing, is a'movable eccentric E. The movable eccentricgE is connected by the usual eccentric strap R and strap rod R to the pump.

plunger P for reciprocating the same. Referring to Fig. 2, the center'of' the movable ter and thus vary the throw of the eccenv v1o eccentric E is at E the center of the fixed eccentric Bis at B and the center-of the, shaft S is at O, and it will be'obvious that the throw of the pump plunger P is deter-.

mined by the distance between E and Since eccentric E is movable on eccentric): B, the center E may be revolved about the-- reached the criticalspeed at which the gov- -ernor begins to act, with any further in-' crease of speed, the centrifugal force of the weights will overcome the tension of the, springs, causing the weights to swing out wardly from the shaft. This in turn will 3 cause the arms e, e, of the movable eccentric to move toward the position of the axial .line also causing the cfenterE to ap-' roach the shaft center 0, thereby decreasg the length of stroke of plunger P, and consequently diminishing the amount of fuel delivery. If this increase of speed is suflicient to cause the. centrifugal weights to move to their extreme outer position so that the pins P P assumeposltions 9 (see Fig. 3), then the pins P P (see Flg. 2) and the arms'e, e, will coincide with axial line time positions ust described, anyincrease of Q1 g and center E of the eccentric E .will coincide with the shaft center 0, causing the pump plunger to have no movement, and consequently, doing away with any delivery of fuel whatever. .Similarly, in actual operation, when the centrifugal weights CC normally occupy some position between the speed will cause the centrifugal weights CG to move-eutwardly and thereby decrease the speed will cause the centrifugal weights' CC I to move inwardly, and thereby increase the stroke of the plunger. q

stroke of, plunger P, and any decrease of It will be noted that the movable eccentric I E directly connected to'thegovernonis subjected to. a reactive thrust .or pressure from the pump plunger, and since this pump ernor in controlling plunger works against extremely high pressures, it is essentlal in order to secure satisfactory operation that the parts shall be so arranged that this reactive thrust from the pump will not be suflicient to seriously disturb! the effective operation of said govthe position of said movable eccentric; mother words, so that the action of the governor in controlling the speed of the engine will not become unstable or unreliable. In the present invention this n messes-j.

: eccentric Efon a fixed eccentric eccentric is connected to the' is era. as bi 'byfmounting the was 3' h i a :large radius r as. compared to the'distance between the 'centersiof. the two eccentrics,

B -Eipreferably when the radius r is'several times greater; than B E The reactive eccentric Lten s to cause a, turning moment of th'e'eccentric E about the fixed eccentric B, which is equal to the thrust (which we shall assumeto be T) times the V distance BE. This turningmoment of the counteracting moment dueto the friction between the movable eccentric E "and fixed eccentric B which is equal to the reactive.

thrust of" lungerjP upon themovable eccentric E, is more or less opposed by a,v '1

thrust of the plunger P (T) timesthe co eflicient of friction between the two surfaces (which. we shall call" 7) times the radius '(r) of the fixed eccentric B. Algebraically -expressed, the effective turnin moment .of E due to the reactive thrust T is B E Tfr and'there will be no tendency of the mov v able eccentric Eto turn upon the fuzedeccentric E, due to the reactive thrust T when T B E Tfr=;",O. In practice it is not necessary nor usually desirable to have the" turning moment of E about B-due to the reactive thrust from the plunger P wholly negatived bythe counteracting moment due to the friction between the two surfaces, but best results are found .to exist when a sub-' stantial amount of this turning moment is thus counteracted by the action gofifriction and-the remaining efiective turning moment, due to the reactive thrust from'the plunger,

helps to overcome the friction, of" rest of the governor mechamsm. I

It a is understood that various may be made without departing from the pirit of the invention as defined in the following elaims. v g What I claimas new is: I 1 1. In a variable delivery fuel pump for inchanges in details and modifications of this invention .ternal combustion engines in combination,

a'centrifugal'shaftgovernor mounted upon ashaft rotating at a speed having a fixed cating pump plunger, ,a bearing for an ceratio to the speed of the engine, a reciprocentric carried by said. "governor shaft, an

eccentriemovably mounted on said bearing 5 to vary its eccentricity relative to said governo'r shaft by causing the center of the eccentric to move in an approximately radial line .toward' the center of the shaft from its position of maximum throw to. a position coinciding -withthe center of the shaft and operablyconnected to said pump plunger, connecting means from said governor for controlling-the positionfof said movable'eccentric on its bearing, the ratio of the distance between the center of said eccentric and the center of said bearing, to the radius of said bearingbeing such that a substantial amount of the turning moment of the movable eccentric on its bearingv due to the reactlve thrust from said pump plunger is counteracted by the action of frictioirbetween said movable eccentric and its bearmg. F

2; In a variable delivery fuel pump for internal combustion engines in combination,

a centrifugal shaft governor mounted upon ashaft rotating at a speed having a fixed ratio to the speed of the engine, a" reciproeating pump plunger, a bearing for; an cecentric carried by said governor shaft,.an eccentric movably mounted on'said bearing to vary its eccentricity relative to said governor shaft by causing the center of the .eccentric to move-in an approximately radial line toward the center of the shaft from its position of maximhm throw to a position;

coinciding with the center of the shaft and operably connected to said pump plunger, connecting means from said governor mounted to rotate with said shaft for controlling the position of said movable eccentric on its bearing, the ratio ofthe distance between the center of said eccentric and the center of said bearing, to the radiusof said bearing being such that a sufficient amount of the turning moment of the movable eccentric on its bearing due to the reactive thrust from said pump plunger is counteracted by the action of friction betweensaid movable eccentric and its bearing to prevent, the re.

active thrust from said pump plunger from disturbing the effective operation of said governor.

a shaft rotating at a speed having a fixed fcatin 3. In a variable delivery fuel pum for internal combustion engines in com ination, a centrifugal shaft governor mounted upon a shaft rotating at a speed having a fixed ratio to the speed of the engine, a reciprocating pump plunger, a bearing for an eccentric carried by said governor shaft, an

eccentric movably mounted on said bearing to vary its eccentricity relative to said governor shaft by causing the center of the eccentric to move in an approximatelyradial line toward the center of the shaft from its position of maximum throw to a position coinciding with the center of the shaft and operably connected to said pump plunger, the distance between the center of said eccentric and the center of said bearing being not over one-half the radius of said bearing, and connecting means from said governor for'controlling the position of said movable eccentric on its bearing.

4. In a variable delivery a centrifugal shaft governor mounted upon ratio to the speed of the engine, a recipropump plunger, a fixed eccentric on saids aft serving as a bearing for a movable eccentric, said movable eccentric mounted tion of'mam'mum-j throw to a :position coernor for controlling. the positionkof said movable eccentric and connected to. said fuel pump for internal combustion engines in combination,

on said fixed eccentric so as to vary its eccentricity relative to said "governor shaft by causmg the center of e eccentric to' move in ,an approximately radial line toward the center of the shaft from itsposiinciding with the center of the shaft and being operably connected to said pump plunger, and connecting means fromfsaid govmovable eccentric on its bearing.

5. In a variable delivery fuel pump for internal combustion engines in combination,

a centrifugal shaft governor comprising weighted members movably mountd: upon a shaft, said shaft rotating at a speed having a fixed ratio to the speed of the engine;- a reciprocating pump plunger, an eccentric fixed on said shaft servingas a bearing for a movable eccentric, said movable eccentric mounted on said .fixed cccen'tric'so that its eccentricity relative to. the governor shaftmay be varied by causing the center ofth'e f eccentric to move in an approm'matel radial line toward the center of the shaft om its inciding with the center of the shaft, said movable eccentric being operably connected to said pump plunger and connecting means between said movable weighted members and said movable eccentric for contro the position of said movable eccentric on its bearing. I

6 .In a variable delivery fuel pump for internal combustion engines in combination, we

a centrifugal shaft governor comprising weighted members movably mounted upon a shaft, said'shaft rotating at a speed having a fixed ratio to the speed of the engine, springs for said weighted members for opposing the centrifugal force acting on said Wei htedmembers during the rotation of sai governor shaft, a reciprocating pum plunger, an eccentric fixed to and surroun ing said, shaft to serveas a bearing for a movable eccentric, said movable eccentric mounted on said fixed eccentric so that its .eccentricity relative to said governor shaft may be varied by causing the center of the eccentric to move in an approximatel radial line towardthe center of the shaft om its position of' maximum throw to a-position coinciding withthe center of the shaft, an eccentric strap and rod operable by said pump plunger for reciprocating the same and connectln means between said movable weighted mem ers and said movable eccentric for controlling the position of said movable eccentric on said fixed eccentric.

7 In a variable delivery fuel pum for internal combustion engines, in .com ination, a rotating shaft, a fuel feeding pump, transmission mechanism for operatmg sald pump from said shaft comprising two ec- 130 25 the operation centrics carried on said shaft, one mounted upon the other, 'said eccentrics being rela tively shiftable to move the center of the outer eccentric in'v an approximately radial '5 line toward the center of the shaft from its position of maximum throw to a position substantially coinciding' with the center of the-shaft, and a governor controlled by the speed of said shaftfor shiftin said eccen-, tries relatively so as to vary t of said pump in feeding said fuel.

8. In a variable, delivery fuel pump for internal combustion engines, jn combinati0n, a rotating shaft, a fuel feeding pump, transmission mechanism for operating said pump from said shaft comprising two eccentrics carried on said shaft, one mounted upon the other, said eccentrics being relatively shiftable to move the center of the outereccentric from its position of maximum throw to a position substantially coinciding with the center of the shaft, and a governor confuel.

. ing a reciprocating plunger working e operation 9. In a variable delivery fuel pump for internal combustion engines, in combination, a rotating shaft, a fuel feeding pump'havagainst a fluid under pressure which gives a reactive thrust in the line of said plungers reciprocatory movement, transmission mechanism for operating said pump from said shaft comfprising twoeccentrics carried on said sha one mounted upon the other, saidec centrics being relatively shiftable to move the center of the outer eccentric in an ap-- proximately radial line toward the center of the shaft from its position of' maximum throw to a position coinciding with the center of the shaft, and a overnor controlled by the speed of said sha eccentrics relatively to thus vary the opera tion of said pum in feeding sald fuel.

Signed at Au urn, N. Y., this 21st day of, September, 1914. v

JAMES A. SEYMOUR.

Witnesses: i

' CELIA C. RICHARDS, JOHN W. CLARK.

for shifting said

Images