US445334A - Steam-engine - Google Patents

Description

(No Model.)

W. WRIGHT.

STEAM ENGINE.

No. 445,334. Patented Jan. 27, 1891.

340441444444 EZZZWZ 7? v 1 L I I I UNTTnn STATES.

PATENT ()FFICE.

WILLIAM WVRIGIIT, OF NElV ZURG, NEXY YORK.

STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 445,334, datedJanuary 27', 1891.

Application filed June 10, 1890.

To all whom it may concern:

Be it known that I, WILLIAM WRIGHT, a citizen of the United States, residing at Newburg, in the county of Orange, State of New York, have invented certain new and useful Improvements in Steam-Engines, of which the following is a specification, reference being had therein to the accompanyingdrawings.

This invention relates to certain new and useful improvements in compound engines; and it has for its object to provide an improved engine of this class, beinga triple con1- pound engine having one higlrpressure, one intermediate, and one low-1:)ressure cylinder, the steam entering the high-pressure, passing from that cylinder to the intermediate, and thence to the low-pressure cylinder, which is connected to a condenser. I place three or more cylinders transversely in line with each other on the beds. I attach each piston-rod to one cross-head, thereby distributing the power uniformly over the cross-head. The transmitting of one-half of the power developed to each cross-head journal, connectingrod, crank-pin, and main-shaft bearing reduces the strains and decreases the friction by one-half on the crank-pins and journals. The engine is square and compact, all its parts are easy of access, and all its strains are equally distributed, all its parts wear evenly, and the liability of getting out of line is reduced to a minimum. It is desirable, when high-pressure steam is used and great power is to be developed, to distribute the work over the engine, so that no part has to hear an excessive strain or the work be unequally distributed; also, that all the power in the steam be given out before the steam is released, and this can only be done by expanding the steam until its pressure about five pounds above a perfect vacuum.

When the pressure of steam requires only about twenty expansions to absorb its power, an ordinary compound engine of two cylinders is all that it requires; but when higher pressure of steam is used a greater number of expansions is required to obtain the power of the steam. Then it is desirable to have a triple compound or three-cylinder engine, the small or high-pressure cylinder of such size and cutting off at such a point of the Serial No. 354,868. (No model.)

stroke as will contain the quantity of steam to give out the whole of the work required and at the same time to be so proportioned with regard to the other two cylinders as to have only one-third of the whole work done by the small cylinder. A second cylinder is proportioned to receive and expand the exhaust-steam from the first cylinder and to do one-third of the work. The third cylinder is proportioned to receive and expand the exhaust-steam from the second cylinder, and,

with the vacuum made by the air-pump and condenser, to do one-third of the work.

In designing a triple compound engine the object is to have the movable and reciprocating parts as light as is practicable and the strains evenly distributed.

For land engines it has been the practice to make what is called the tandem stylethat is, the three cylinders are placed one behind the other, having all the piston-rods on one line, one connecting-rod, and one crankpin and crank. The objection to this plan is, the whole work and strain has to be conveyed through the piston-rods in the following manner: The first and smallest pistonrod conveys one-third of the work to the second piston-rod. This rod in turn conveys two-thirds of the work to the third pistonrod, which rod has to be large enough to convey the whole work or power to the crosshead. The cross-head pin and crank-pin have to be large enough to withstand the thrust, and must have surface suficient to reduce the friction in order to prevent heating. The connecting-rod and crank have to be made heavy enough and strong to convey the power to the shaft. The crank-shaft bearing requires to be large in diameter and long to withstand the strain and to reduce the friction per square inch of surface in order to prevent heating, as the whole work or power has to be transmitted through these parts to the main drivingnilley. Another objection to this style is its great length, requiring each cylinder to be placed far enough from the others to allow sufficient space to take off the head in order to get at the pistons when necessary, and in case the pistons are to be taken out, all of them have to be forced oil? the rod and taken out between the cylinders. Still another obj ection lies in the diflic-ulty of keeping the cylinders in line. Much labor and time are required when any of the parts have to be taken apart for examination.

A triple compound engine arranged as shown in the drawings has not the objections that exist in the tandem style. The foundation required is less, and the engine being nearly square, gives a more solid foundation.

The three cylinders being arranged side by side, each having its own piston-rod connected to the cross-head, either piston can readily be removed by taking off the back head and disconnecting the piston-rod from the cross-head. The cylinders being bolted to the beds, cannot get out of line, as often happens in the tandem style. As each cylinder exerts approximately the same power, a uniform load is distributed over the cross-head. The crossliead having a journal on the ends just outside of the slides, and the outer cylinders having their piston-rods connected to the crosshead inside 'of the slides, brings the power applied near the line of resistance, or the outer piston-rods maybe connected to crosshead in line with the connecting-rods, thereby bringing the power in the direct line of resistance. One-half of the power of the three cylinders is conveyed to each of the cross-head journals, and through their respective connectingrodsto each crank-pin and crank. The crankshaft bearing on each side of the drivingpulley with this arrangement has the strain equally divided. The crank-pins, cranks, connecting-rods, and crankshaft bearings have only half the work on each. Therefore they can be lighter, as the thrusts and friction are reduced one-half.

A triple compound engine arranged as per my invention takes up less room, is more compact and substantial, and all its parts are easy of access. The engine-room for this style of triple compound engine would be of better shape than the one required for the tandem triple compound.

Other objects and advantages of the invention will hereinafter appear, and the novel features thereof will be specifically defined by the appended claims.

The invention is clearly illustrated in the accompanying drawings, which, with the letters of reference marked thereon, form a part of this specification, and in which- Figure 1 is a plan view of a triple compound engine embodying my invention. Fig. 2 is a side elevation of the same.

Like letters of reference indicate like parts in both of the views.

Referring now to the details of the drawings by letter, A designates the main bed or frame of the engine.

Bis the small or high-pressure cylinder; 0,

the intermediate cylinder, andD the low- F a pipe conveying steam from the'highpressure cylinder B to the intermediate cylinder (J, and G is a pipe for conveying steam from the intermediate cylinder 'to the lowpressure cylinder 1).

H are the piston-rods of the various cylinders. They are all connected to a common cross-head I, thereby distributing the power uniformly over the cross -head. This crosshead may be of any preferred form of construction; but I prefer the braced or trussed form shown in Fig. 1, which gives great strength with less weight and material.

I J are the connecting-rods, one upon each side of the engine and one at each end of the cross-head and connecting said cross-head to' the crank-pins, as shown.

K are the cranks.

K is the main shaft and L its bearings.

M is the main driving-pulley, arranged centrally onthe main shaft.

Nare the eccentrics for operating the valves, and O are eccentric-rods connected with the transverse rock-shaft P.

Q are rods for the valve-gear, attached to levers on the rock-shaft and pins on the wrist plate.

R is the governor-pulley, designed to be connected with the governor (not shown) in any suitable manner.

The low-pressure cylinder D is designed to be connected to a suitable condenser in any desired manner.

I have shown but three cylinders, as that is the number I design to usually employ; but

more may be employed, if desired, without departing from the spirit of the invention, and instead of the wide-faced driving-pulley, gearing may he sometimes substituted.

\Vhat I claim as new is- 1. The combination, with the bed and the three cylinders of varying capacity arranged in line transversely of said bed, of the crosshead common to and connected with all the piston-rods of said cylinders, the drive-pulley arranged centrally in relation to said cylinders, the crankshaft bearing on each side of the drive-pulley, and the connecting-rods, one upon each side of the engine and connecting the cross-head to the crank-pins, substantially as specified.

2. The combination, with the bed and the three cylinders of varyingcapacity arranged transversely thereof, of the piston-rods, the cross-head common to and connected with all of said rods and having a journal on the ends outside of the slides, the piston-rods of the outer cylinders being connected to the crosshead inside of the slides, the drive-pulley centrally arranged, the rock-shaft P, the connecting-rods connecting the same with the eccen tries, and the rods J, one upon each side of the engine and connecting the cross-head with the crank-pins, substantially as shown and described. V

3. The combination, with the bed and the three cylinders of varying capacity arranged IIO transversely thereof, of the piston-rods, the l of the engine and connecting the cross-head 1o trnssed cross-head common to and connected I with the crank pins, substantially as shown with all of said rods and having ajournal on 1 and described. the ends outside of the slides, the piston-rods In. testimony whereof I afiix my signature in of the outer cylinders being connected to the i presence of two witnesses.

crosshead inside of the slides, the drive-puL t YVILLIAM WRIGHT. ley centrally arranged, the rock-shaft P, the t Witnesses:

con meeting-rods connecting the same with the WILLIAM HUMPHR EYS,

eccentrics, and the rods .T, one upon each side CHARLES J. HOWELL.

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