US625900A

US625900A - Single-expansion plunger pumping-engine

Info

Publication number: US625900A
Authority: US
Publication date: 1899-05-30
Anticipated expiration: 1916-05-30

Description

No. 625,900. Patented May 30, I899. AMH. REEDER.

SINGLE EXPANSION PLUNGER PUMPING ENGINE.

7 (Application filed Ju1y 1, 1898.) I (No Model.) 2 Sheets-Sheet l.

No. 625,900. Patented May 30, I899.

A. H. REEDER.

SINGLE EXPANSIONPLUNGER PUMPING ENGINE.-

[Applicatiel l filed July 1, 189B.) (No Model.) 2 Sheets-Sheet 2.

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UNITED STATES.

PATENT ()FFICE.

ANDREW R EEDER, OF UNIONTOWN, PENNSYLVANIA.

SINGLE-EXPANSION PLUNGER PUMPING-ENGINE.

SPECIFICATION forming part of Letters Patent No. 625,900, dated May 30, 1899. Application filed-July 1, 1898- Serial No. 684,948. (No model.)

' To a whom it may concern.-

Be it known that I, ANDREW H. REEDER, a citizen of the United States, residing at Uniontown, in the county of Fayette and State of Pennsylvania, have invented new and useful Improvements in Single-Expansion Plunger Pumping-Engines, of which the following is a specification.

This invention relates to a sin gle-expansion plunger pumping-engine, and has for its object to enable steam to be used expansively in a steam pumping-engine employing but a single steam -cylinder by providing novel power-transmitting mechanism by means of which the expansive force of the steam is utilized throughout the entire stroke of the piston in such manner as to exert an effective propulsive or lifting force on the pump.

In engines generally the purpose of using steam expansively is to utilize the expansive force which steam has under pressure, so as to obtain the full effective force of the steam in the most economical manner. In steam pumping-engines this is largely being accomplished at present by employing doub1e,triple, and quadruplex expansion engines. Such engines are necessarily complicated and expensive, and it is the purpose of the present invention to accomplish the same result with a sin gle-cylinder ex pansion-en gine,wherein the steam acting by expansion on the piston in the stealn-cylinder communicates motion to the piston-rod and through the latter to the pump-plunger. The pump-plunger,h0wever, 7

works against a constant water-pressure during the entire length of its stroke, and therefore requires a constant pressure on the piston in the steam-cylinder to overcome the water-pressure. Therefore when the steam is cut off from the engine-cylinder before the end of the stroke of its piston the expansive force of the steam diminishes as the piston continues its stroke and at some period during the stroke would be insufficient to overcome the water-pressure in the pump and the pump would stop. I avoid such a result by providing novel mechanism for transmitting the power from the engine to the pump in such manner as to obtain an increased leverage as the engine-piston travels toward the end of its stroke sufficient to overcome the loss of claimsfollowin g the description, reference being had to the accompanying drawings, form ing a part of this specification, wherein Figure 1 is a View in side elevation of my improved pumping-engine. Fig=2 is a top plan View thereof. Fig.3 is a vertical longitudinal central sectional view of the engine cylinder, illustrating the cut-off valve mechanism; and Fig. 4.isatransverse sectional view taken on the line 4 4 of Fig. 3.

Referring to the drawings, the numeral 1 indicates the pump, and 2 and 3 the pumpplungers. This pump is an ordinary doubleplunger pump of usual and well-known construction, the only especially-designed feature of construction consisting in making one of the plungers larger than the other, as will hereinafter be explained. The plungers 2 and 3 are arranged in the opposite ends of the pump-cylinder, as shown, the plunger 2, which Idenominate the near plunger, being smaller than the plunger 3, which I term the far? plunger. The relative sizes of the two plungers are shown in the present instance as being as twelve is to fourteen and one-sixteenth. The near plunger 2 is connected by a connecting-rod 4 to a cross-headfl, which is adapted to reciprocate between ways 6 on the pump frame or casing 7, and the far plunger 3 is connected to two side rods 8,

which are arranged on opposite sides of the pump and are adapted to reciprocate in bearings 9 on the pump frame or casing. The other ends of the rods .8 are connected to cross-heads 10, arranged to slide on the ways 11.

The numeral 12 indicates the engine-cylinder, mounted on a

suitable frame

13, and 14 the piston-rod, which is connected at its outer 16, attached to the frame .13.

end to a cross-head 15, reciprocating on ways Journaled in the frame 13 is a rock-shaft 17, on which are rigidly fixed three crank-arms, respectively numbered 18, 19, and 20. The end of the crank-arm 18 is connected by a pitman 21 to the cross-head 15, and the parts should be so proportioned and arranged that the crankarm 18 will be oscillated through an arc of about fifty-eight degrees at each complete stroke of the piston. The crank-

arms

19 and 20. being fixed on the rock-shaft 17 will of course also oscillate simultaneously with the crank-arm 18 through corresponding arcs. As shown, the crank-

arms

19 and 20 are fixed on therock-shaft at an angle to one another and on opposite sides of the mean vertical center of the rock-shaft-that is to say, as the rockshaft is rocked the crank-arms will respectively approach and recede from opposite sides of a vertical line passing through the rock-shaft. The crank-arm 19 is connected to the cross-head 5 by a connecting-rod 22, and the crank-arm 20 is connected by a connecting-rod 23 to the cross-head 10. I have shown two crank-arms 20, set at the same angle 011 the rock-shaft, and two connectingrods 23, attached to said crank-arms and to two cross-heads but inasmuch as this duplication of parts is merely for the purpose of applying the power evenly to the far plunger and directly in the line of movement of the latter and inasmuch as these duplicate parts move in unison and practically form a single operative arrangement I refer to them in the singular for the sake of simplicity of description.

The operation of this part of the invention is as follows: The piston-rod 14 advances on its outstroke by the direct action of the steam until point is reached when the steam is cut off from the cylinder, (by suitable mechanism hereinafter described,) after which the piston will be advanced by the expansive force of the steam alone. At the time the steam is cut off, however, the crank-arm 19 will have advanced to a point where the leverage on the connecting-rod 22 will be rapidly increased, while the speed of the crosshead 5, which is connected to the near plunger 2, is rapidly decreasing. Hence as the piston-rod is making its stroke it is exerting through the medium of the mechanism described a rapidly-increasing leverage on the near plunger, but at the same time is moving the latter at a rapidly-decreasing speed, and

' in this manner the gain in power due to the increased leverage will fully compensate for the loss of power as the steam expands in the steam-cylinder. The action is practically the same on the return stroke of the piston, excepting that the far plunger is entering its end of the pump-cylinder, while the near plunger is being Withdrawn. As the piston-rod moves on its return stroke the crank-arm exerts an increasing leverage on the far plunger through the medi um of the connecting-rod 23, cross-head 10, and side rods 8; but as the leverage increases it is manifest that the speed of the far plunger decreases.

In the practical operation of the parts constructed and arranged as described there will be found to exist a difference in the amount of leverage on the two pump-plungers as well as in the length of stroke of the same. This is owing to the difference in length of the connecting-rods 22 and 23 and also to the fact that all points in the are described by the crank-arm 20 are more distant from the crosshead 10 than is the rock-shaft 17, while all points in the are described by the crank-arm 19 are nearer the cross-head 5 than is said rock-shaft. The far plunger, therefore, has a shorter stroke, but more power than the near plunger, and for this reason I make the far plunger of greater diameter than the near plunger, whereby the amount of water displaced by the pump on the outstroke of the piston rod will approximately equal the amount displaced on the instroke and will also require the same amount of power to be developed by the engine on both the out and in strokes.

In Figs. 3 and 4 I have illustrated'improved cut-off mechanism for cutting off the steam from the cylinder at suitable points in the in and out strokes of the piston. Referring to said figures, the numeral 12 indicates the steam-cylinder, 14 the piston-rod, 14 the piston, and 24 the valve-chest. The opposite ends of the cylinder communicate with the valve-chest by the usual steam-ports 25 and 26, and branching from the latter are the exhaust-ports 27 and 28, which are adapted to be alternately put into communication with an exhaust-outlet 29 by a piston-valve 30. The piston-valve 30 is adapted to alternately straddle the exhaust-outlet 29 and one of the exhaust-ports, as shown, and is reciprocated byv a rod 31, provided at its opposite ends with pistons 32 and 33, which are adapted to respectively reciprocate in cylinders 34 and 35, formed in the opposite ends of the valvechest, as shown. The outer ends of the cylinders 34 and 35 communicate by steam-ports 36 and 37 with an auxiliary steam-chest 38, and the ports 36 37 are adapted to be alternately placed in communication with an exhaust-outlet 39 by an auxiliary valve 40. The piston-valve 30 and auxiliary valve 40 are of usual and well-known construction and need not be explained in detail. Both the valvechests are provided with a constant supply of steam. Arranged to slide in recesses 41 and 42 in the bottom of the main-valve chest are cut-off valves 43 and 44, which are adapted ciprocate in bearings on the opposite sides of the valve-chest are two side rods 46, which are connected at their opposite ends to crossheads 47. Fixed in each of the cross-heads, opposite the ends of the valve-rods 45, are threaded studs 48, the threads of each of said 1 studs being re versely arranged to the threads on the corresponding valve-rod. The ends of the valve-rods are coupled to the studs by right and left handed threaded sleeves 49, whereby by turning the sleeves the cutoff valves may be adjusted to cut oif'sooner or later in the stroke of the piston, as will more fully hereinafter appear. Fixed to one of the cross-heads 47 is one end of a connecting-rod 50, (see Fig. 1,) the other end of which is connected to a pivoted lever 51. The lever 51 at its lower end is pivotally connected to one end of a link 52, the other end of which is connected to the crank-arm 18. The connecting-rod is connected to the lever 51 below the fulcrum of the latter, and to the free end of said lever, on the opposite side of the fulcrum, is connected a sleeve 53, that is loosely mounted on the stem 54 of the auxiliary valve 40. Collars or nuts are adjustably fitted on the stem 54 and 'are adapted to be alternately engaged by the sleeve 53 on the lever 51, and

thus shift the auxiliary valve 40.

The operation of the valve mechanism is as follows: As the crank-arm 18 is oscillated back and forth by the engine the auxiliary valve and cut-off valves are simultaneously reciprocated in opposite directions by the lever mechanism above described. When the auxiliary valve has assumed the position shown in Fig. 3, the steam from the auxiliaryvalve chest passes behind the piston 32 and throws the piston-valve 30 into the position shown, the steam behind the piston-33 escaping through the port 37 and exhaust-outlet When the parts are in this position, the steam passes from the main-valve chest by the port 25 behind the piston 14 and moves the latter in the direction of the arrow, the steam in front of the piston escaping through the exhaust-port 28 and exhaust-outlet 29. As the piston moves forward in the direction shown the cut-01f valves 43 and 44 are moved forward in the same direction, the valve 43 gradually closing the steam-port 25. After the valve 43 has closed said steam-port, entirely cutting off the live steam from the cylinder, the piston continues to be moved forward by the expansion of the steam, and during this forward movement the valve 44 is withdrawn from across the steam-port 26, (the said port remaining closed by the pistonvalve 30,) thus placing said port in readiness for the admission of steam to the cylinder for the succeeding or return stroke, which will occur as soon as the piston-valve 30 is reversed. The stems ofthe cut-off valves and the auxiliary valve are connected to the ac tuating-lever 51 on opposite sides of its fulcrum, as has been before described, and there- 53 on the end of the lever 51 is moved in the opposite direction. Hence at a certain period of the described motion of the piston 14 the sleeve 53 will engage one of the collars ornuts 55 on the valve-stem 54 and throw the auxiliary valve in the reverse direction, thus placing the port 36 in communication with the exhaust-outlet 39 and opening the port 37. The steam from the auxiliary steam-chest will then be admitted behind the piston 33 and reverse the piston-valve 30, when the piston 14 will begin its return stroke.

It will be readily understood that by turning the sleeves 49 in one direction or the other the cutoff valves maybe adjusted to cut oif the steam from the cylinder at different points during the stroke of the piston and that by adjusting the nuts or collars 55 on the valvestem 54 the movement of the auxiliary valve may in like manner be regulated.

While -I have shown a pump having a far and near plungerarranged on opposite sides of the pump, I do not wish to be understood as limiting myself specifically to such an arrangement, as it will be manifest that two pump-cylinders, each having a plunger, may be arranged opposite each other in line and the steam-cylinder arranged intermediate the two pump-cylinders, the crank-arm mechanism being interposed between the opposite ends of the piston-rod and the plunger-s, or the two pump-cylinders may bearranged side by side without departing from the spirit of my invention.

I have described my invention as being used in connection with aplunger-pu mp; butit will be manifest that the same could be used to equal advantage in connection with an air pump or compressor.

Having described my invention, what I claim is- 1. Thecombination with two independent pump-plungers and their cylinders, of a single-cylinder expansion-engine, a rock-shaft rocked by the engine, two cranks fixed on said rock-shaft at an angle to one another, and on opposite sides of the mean vertical center of the rock-shaft, and connecting-rods each connected at one end to one of said cranks and at the other end to one of said plungers, the arrangement being such that as the expansive force of the steam in the cylinder de creases the respective cranks exert an increased leverage on the plungers, substantially as described.

2. The combination with two independent pump-plungers and their cylinders, of a single-cylinder expansion-engine, a rock-shaft rocked by the engine, two cranks fixed on the rock-shaft at an angle to one another and on opposite sides of the mean vertical center of the rock-shaft, and connecting-rods each connected at one end to one of said cranks and at the other end to one of said plungers, the

arrangement being such that as the expansive force of the steam in the cylinder decreases the respective cranks exert an inof said cranks and at the other end to one of said plungers, the arrangement being such that as the expansive force of the steam in the cylinder decreases on each stroke of the engine-piston one of said cranks exerts an increased leverage on its corresponding plunger, substantially as described.

4:. The combination with a double-plunger pump having reciprocating plungers arranged in its opposite ends, of a single-cylinder expansion-engine, a rock-shaft arranged intermediate the engine and pump and constructed to be rocked by the en gine,two cranks fixed on the rock-shaft at an angle to one another and on opposite sides of the mean vertical center of the rock-shaft, a connecting rod connected atits opposite ends respectively to the near crank and plunger, and a connecting-rod connected in like manner to the far crank and plunger, substantially as described and for the purpose specified.

5. The combination With a double-plunger pump having independent reciprocating plnngers arranged in its opposite ends,of a single-cylinder expansion-en gine, a rock-sh aft arranged intermediate the engine and pump and constructed to be rocked by the engine, two cranks fixed on the rock-shaft at an angle to one another and on opposite sides of the mean vertical center of the rock-shaft, a connectingrod connected at its opposite ends respectively to the near crank and plunger, and a connecting-rod connected in like manner to the far crank and plunger, the far plunger being of a greater diameter than the near plunger, substantially as described and for the purpose specified.

6. In a single-cylinder expansion-engine, the combination with the cylinder and valvechest, of steam-ports 25 and 26 connecting the steam-chest with the opposite ends of the cylinder, branch ports 27 and 28 leading from the steam-ports, an exhaust-outlet 29, a reciprocating valve 30 arranged to simultaneously open the steam-port 25 and close the exhaustport 27 at one end and close the exhaust-port 28 at the other end, means for reversing said valve at each stroke of the piston, cut-off valves arranged .to alternately close the steamports 25 and 26, mechanism for operating the cut-off valves, and means for adjusting the cut-off valves to regulate the point at Which the steam is cut off from the cylinder, substantially as described.

7. In a single-cylinder expansionengine,

the combination with the cylinder and valvechest, of steam-ports 25 and 26 connecting the steam-chest With the opposite ends of the cylinder, branch ports 27 and 28 leading from the steam-ports, an exhaust-outlet 29, a reciprocating valve 30 for controlling said ports, means for actuating said valve, cut-01f valves arranged to alternately close the steam-ports 25 and 26, threaded valve-stems for said cutoff valves projecting through the opposite ends of the valve-chest, side rods 46 arranged to reciprocate in bearings on opposite sides of the valve-chest, cross-heads fixed to the opposite ends of the side rods, threaded studs 48 fixed in the cross-heads opposite the threaded ends of the valve-stems, the threads on the valve-stems being formed reversely to those on thestuds, right and left threaded sleeves coupling said valve-stems and studs together, and means actuated by the steam-piston for reciprocating the cross-heads to actuate the cut-off valves, substantially as described.

In. testimony whereof I have hereunto set my hand in presence of two subscribing Witnesses.

ANDREW H.- REEDER.

Witnesses:

o. 1-1. SEATou, WM. SEARIGHT.