US93125A - Improvement in steam-engine-valve gear - Google Patents

Description

iltitrd gitana .gaat entre LettersPateut'No. 93,125, dated July 27, 1869.

IMPROVEMENT IN STEAMeENG-INE-VALVE GEAR.

.'she Schedule referred to in these Letters Patent and making part of tne same,

To all 'whore it mag/'concern f Beit known that I, G. E. RYMES, of Somerville, in the county of Middlesex, andl State of Massachusetts, have. invented certain new and useful Improvements in Steam-Engine-Valve Gearing; and I do hereby de` clare that the following taken in connection with the drawings which accompany and form part of this speci- -iication, is a description of my invention, sufiicient to enable those skilled in the art to practise it.

My invention consists primarily in such an arrangement of rotary valves and valve-seatsas enables me to control the entrance and exhaust-passages properly, by continued rotations of the valves, instead of by giving to them the vibratory or oscillating movements which have hitherto been employed for that purpose, by which invention Iam enabled .to simplify the valve-gearing of steam-engines, to render it lnois'eless in its operation, and to keep the faces of the valves and.valve seats in good order;and by which I am enabled to dispense with the eccentrics, cams, rocker-shafts, and

slide-bearings, usually found in steam-enginegearing, substituting therefor ordinary gear-wheels androtating shafts.

In the drawings- Figure 1 shows in sectional plan sovmuch of a steamr engine as is necessary to illustrate my invention, a denoting part ofthe steam-cylinder, and b b, valve-chests, one ateach end of the cylinder. v

'Ihe valve-chests shown arecylinders with their axes at right angles to the axis of the-steam-cylinder, the chests being united by a connecting-passage, c, into which the direct steam is introduced from the boiler.

One part of each chest, ou the` face of which" is made the exhaust-valve seat, is cast with the steamcylinder, and the outer portion of each chest is fixed upon the. part integral with the steam-cylinder; said outer part having within it a partition-diaphragm or head, forming the seat for the steam-valve. These seats are shown in elevation'in Figures 2and 3, fig. 2 showing the exhaust-valve seat, and iig. 3 showing the steam-valve seat; said seats being also-respectively marked d and e.

The outer end of each chest b is closed by a head, f, through a suitable packing or stufng-box, in which passes the valve-stem or shaft g, on which are fixed the exhaust-valve 71, steam-'valve z', and bevel-gear j.

Elevations of the exhaust-valves are shown in Figures 4 and 5, the exhaust-valve being-shown in iig. 4 as on its seat, and uncovering the exhaust-ports, and in fig. 5 as on its seat covering the exhaust-ports.

Elevations of the steam-valves are shown in Figures 6 and 7, the steam-valve being shown in fig. 6 as covering the steam-ports, 'and iu g. 7 as uncovering -the steam-ports.

Figs; 5 and 7 show the exhaust and steam-valves at Vonee'nd of the steam-cylinder, the'steam-valve being open, and the exhaust-valve closed; and figs. 4 and 6 show the exhaust and steam-valves at the other end of 'the steam-cylinder, the exhaust-valve being shown open, and Athe steam-valve closed,'so that whenA the valves arepin therelative position shown, the piston is moving from right to left,`or from the back to the front end of the steam-cylinder; figs. 5 and 7 showing the valves pertaining to the rear end of5 the cylinder, and figs. 4 and 6 showing the valves pertaining-to the frontend of the cylinder.

Two ports are shown in each of the exhaust and steam-valve seats, and four cprresponding openings in each ofthe disk, exhaust, and steam-Valves, so arranged that both exhaust-ports are ropened and closed at the same time, as are also the ports in the steamvalve seats. l y

The shaft k, which is located parallel with the piston of the steam-cylinder, is driven b y gears from the main shaft of the engine, so as to have the same number of revolutions with the mainzshaft.. Y

0n shaft k are xed bevel-pinions l, as shown, hav-v ing one-fourth the numberof teeth inthe gears j, with which the pinions lmesh, so that foreach stroke of the piston, thevalve-shafts g and the valves hand t will make one-eighth of a complete revolution, or a fourth of a complete revolution for each double stroke of the piston', and one complete revolution of themain shaft of the engine, so that it will be seen 'that the steam-ports are opened and shut 'at one end ofthe cylinder by a single piston-stroke making an eighth of a revolution-of the valve, and a halfa revolution of thev mainV shaft, and that the exhaust-ports at the' opposite end are also opened and closedv inthe same4 time by the same movement of the piston, thus letting the steam-cylinder receive steam at one end, and exhaust at the other, which operations will be repeated at op.- posite ends of the cylinder for the return-stroke of the piston, the operations described being repeated continuously by the repeated strokes of the piston, and

the continued rotation of the valves.

The faces ofthe lvalve-seats are recessed, as seen at fm, the object lof this being to admit steam to. both sides of the valves to partially balance them, to reduce the friction which would result if the valves were forced upon their seats with thepessure of the steam upon their entire area. y

ABearing-faees n in the plane of the valve-seat surfaces around the ports, are'lo'cated, 'as shown, to prevent deection of the disk-valves.:

The cntoif valves o are made each as two opposite sectors of a disk, fitting against the face ofthe steain-v valve opposite to' that which bears upon the steamvalve seat e.

The cut-off valves are pivoted on the valve-shaits-g, and are connected, each with the other, and to an arm, p, on arocker-shaft, q, on which is a rockerarm,o', which is worked by a regulator, so that the position of the cutoi.valves is regulated with reference to the openings through the-steam-valve, so that the steam is cut olf sooner or lateratA any part of the piston-stroke, according to the location at which the cut-oil' valve is placed by the regulator.-

The face of the steam-valve, against which the cut` ci? valve works, is recessed, as shown, so as to admit steam under. the cutoff valve, except where it bears. against the projections,surroundingthe openings in l the steam-valve, this` reducing the pressure and friction on the cutoii` valve. y

The valve-cases may be arranged with their axes parallel to the axis of the steam-cylinder, the cases then having each two 'removable heads, which would facilitate getting at the valves, to inspect and adjust them.

In such an arrangement there .would be but one y valve-stem shaft; which would be parallel with the axis of the steam-cylinder, and wouldhaveupon it one spur-gear, into which would mesh a spur-pinion on the shaft k, having one-fourth of the number of the teeth on the spur-gear. This arrangement is indicated in the diagram, Figure 9.

Experienced machinists will recognize the fact that valves made to turn continuously in one direction, will wear themselves, and their valve-faces, much more uniformly thanA they do when they have a movement back and forth, as in reciprocating, 6r in vibrating or oscillating.

The valve-seats and valves may be constructed so as to give any desired lap, and ,the valves may be adj usted to give any desirable lead, according to the circumstances of any case, and to conform tc the best env gineering theories and practice. l

By preference I make the faces of the valves and valve-seats as planes, but theyrmay be' dished, with-` out departure from my invention, or the valves may be madeas cylindrical or conical plugs, or parts there of, or as cylindrical or conical tubes, or parts thereof, without departure from my invention, .so long as the valves are continuously rotated in one direction, and are not moved back and forth -by vibration or oscillation. But iu practising my invention, I greatly pre- `fer to employ hat disk-valves or portions of dat disks,

as they can more readily be adjusted to compensate -fcr wear of their* faces, and the wear of their seats,

rocates, the combination with each of two steam-valves,

arranged to rotate constantly in one direction, and

synchronouslywith each other and the main crankl shaft, of a backer`cut-oil` valve, arranged to be vi brated by connection with a regulator, to cut ois'team at variable parts of the piston-stroke, substantially as described.V

O. f E. RYMES.

Witnesses:

J. B. CROSBY, C. WARREN BROWN.

Images