US2464112A - Cylinder head for superheated steam engines - Google Patents

Description

March 8, 1949. M ARNO 2,464,112

CYLINDER HEAD FOR SUPERHEATED STEAM ENGINES Filed Aug. 17, 1945 2 Sheets-Sheet 'l Ill Inventor -4 N fiQIPEY'MARNoLD,

Y WWW Em March 8, 1949. ARNQLD 2,464,112

CYLINDER HEAD FOR SUPERHEATED STEAM ENGINES Filed Aug. 17, 1945 2 Sheets-Sheet 2 TU] HZIERYMARNZZZ:

N By

- arm Weave; E M51818 Patented Mar. 8, 1949 CYLINDER HEAD FOR SUPERHEATED STEAM ENGINES Harry M. Arnold, Golden, Colo.

Application August 17, 1945, Serial No. 611,117

2 Claims.

This invention relates to a steam engine using superheated steam and other very hot gases, the general object of the invention being to provide a circulating system for the cylinders, cylinder heads, pistons and packing glands of the engine which is so constructed and arranged that it will maintain the parts at a temperature that efiicient lubrication of the various parts of the engine can be obtained by utilizing very little cylinder oil and in some cases by using moisture lubricated piston rings. When moisture lubricated rings are used, they may be dampened by introducing water into the piston, or by introducing water into a channel cut in the cylinder barrel, or by using moisture formed from a partial condensation of the expanding steam.

When ordinary dry steam expands in a steam engine, considerable condensation occurs making possible oil-free cylinder operation. When very highly superheated steam is utilized the cylinder becomes dry and often times too hot for effective lubrication with the best cylinder oils now in use.

By cooling the cylinder to a temperature slightly below the condensation temperature of the expanding steam, a small amount of superheated steam will condense upon the cylinder barrel affording a moist surface. Highly superheated steam cools and condenses very slowly as compared with saturated steam so that the loss in power on the piston of the engine during the power stroke is far less than is experienced in the conventional saturated steam engine.

The heat absorbed by the jacketing system of the engine can be imparted to the boiler feed water so that less heat is required to evaporate the water in the boiler. To achieve this, the entire jacketing system must be made strong enough to withstand a pressure slightly above the boiler pressure used in connection with the engine. By mixing some steam or hot water from the boiler with the cold feed water, nearly any desired cylinder temperature can be maintained.

Still another important item to be considered in Uniflow steam engines utilizing very highly superheated steam, is uneven expansion of the cylinder and cylinder heads. Cylinders for use with highly superheated steam are often bored on a slight taper from each end to the center where the exhaust communicates with the cylinder, so the cylinder barrel will become of uniform bore when it is heated to a higher temperature at the ends than at the center. With the circulating system illustrated in this patent application, the entire cylinder assembly may be held at a uniform temperature thereby eliminating mechanical difficulties now experienced from uneven heating of the cylinder.

This invention also consists in certain features of valve construction and means of cooling the valve stems and valve guides. The combination and arrangement of the several parts are hereinafter fully described, illustrated in the accompanying drawings and specifically pointed out in the appended claims.

In describing the invention in detail, reference will be had to the accompanying drawings wherein like characters denote like or corresponding parts throughout the several views, and in which:

Figure 1 is a longitudinal sectional view through the engine.

Figure 2 is a fragmentary sectional view through a, cylinder provided with a floating piston and piston rod so constructed that water can enter the piston through the piston rod, or through an opening in the side of the cylinder barrel.

Figure 3 is a transverse sectional view taken on a line 33 of Figure 1, and

Figures 4 and 5 are similar views of modified cylinder heads.

In these drawings and referring to Figure 1 the numeral l indicates a special form of oscillating cam so constructed that it can be used to actuate one or two valves, depending upon whether the engine is only single acting or double acting as illustrated in Figure 1. The cam I first contacts the follower 2 at a point nearly in line with the center of the cam shaft 3. At this point the velocity of contact is very slow and the lifting power of the cam is very great. The numeral 4 indicates a double beat tubular valve having its inner and outer ends flared to admit steam into the cylinder internally and externally of the valve and also having an adjustable seat and.

labyrinth seal in the inner valve seat 5, while the main portion of the tension on the valve during closed position rests against the outer valve seat 6 to prevent leakage of the steam. The valves are provided with valve stems I having annular grooves 1a to collect moisture for a seal; the condensation occurs in the valve guides 8 which are cooled by the jacketing system 9 of the engine. The springs Ii] hold the valves 4 in closed position and are secured to the stems I by the pin and washer II.

In Figure 2 it will be seen water enters the hollow piston rod l2 and is conducted through the passage way [3 to the center of the piston l 4. The water passes through small radial openpiston rod I2 and the extended tail rod l6 which i in turn transmit the load to any one of a number of conventional cross-heads now in common use (not shown). Only the rings 55 contact: the.= cylinder barrel 20 to prevent steam from blowing; past the piston i4. When excessive temperatures are employed, a water jacketed packing gland 31 may be necessary for the piston rod. t2 anditail.

rod l6. Another method of moistening the piston rings is and the cylinder barrel 28 where' the rings contact it, is to introduce Water through thepassage way lZa inthe cylinder'barrel zfl and distribute it around the cylinder barrelby use'of a groove |3a., The rings will pick up moisture: as they pass to and fro. over the groove 13a.

Referring again. to Figure 1 itwillbe. seen-the superheated steam enters theenginethrough the pipes l'i and'valve chests l8.- Steam is, alternately admitted to the two ends of the. cylinder by" the valves Il and after pressing the piston liitozther opposite end of the cylinder 2-0 it exhausts through the centrally arranged Uniflow exhaust ports 2|. The piston; I9 is supported by load: carrying rings 22 while sealing rings 23 Wipethe moisture to the exhaustports 2 I. Thepiston:

heads |9- are a little; small: in diameter soexpansion due to elevated temperatures will: not. cause metal to metal contact with the cylinder 20. The jacketing system 9 surrounds the endportions of the cylinder Ziland the. valve: guides:- 8; A jacket-9 is-formedzaround thepack-ing gland 3.|- and the packing is held in position by the: insert 32. The piston i9 is a single piece mounted; on the piston rod E2. Bolts zil holdthe cylinder heads 24 and 25 and the valve. chests. l8. securely to. the cylinder 20. Brainand relief valves: 35 should be used on the cylinder torelieve. excess compression when starting the engine. from rest and to allow any condensation, which may ac cumulate in the ends of the cylinder 20, to. be: blown out. A long counter-bore 36 extends-into. each end ofthe cylinder ZO-sothe piston rings- 22 and zs contact onlythe portion of the cylinder barrel 20' backed up directly by the. circulating. system 9.

Referring now to Figures 3,. 4 and 5,, three, types. of cylinder heads are illustrated insection. and are denotedby. numerals 24, 2:5 and.2 6 The. cylinder head 24 isintended forthe end ofthe cylinder wherethe. piston rod 12. does-not enter. The core. of solid metal 21,, affords. additional. strength so-a large. flatsurface is avoided. Two; cores 29 are provided and. tapped for cylinder. head. bolts 28. The circulating. chamber l-l surs; rounds the valveseat flange Stand the-cores 21 and 29. v

Numeral. 2 5 denotes acylinder head. of; different shape. The bolts 28 arev set in. closer. to. the flange 3B. The core 2.! is bored for a-pistonro'di l2 while the cores 29 are taped for bolts 28. Thecirculating chamber 9 is formed aroundthebolt's 28 and flange 3i) and also encircles the cores ET and 2-9. a

The cylinder head 26 is'intended foran engine having several cylinders made together. The

603165 29 aretappedforbolts 2 8.: Thecores 2 'l are 75.

4. omitted but must be used if a piston rod I2 is to pass through, or if high jacketing pressures are involved. The circulating chambers 9 are independent of each other and each has its own entrance 33 and exit 34 for the cooling agent. The entrance 33 in Figures 3, 4 and 5 is cut away but can be distinctly seen in Figure 1.

This improved engine promotes expansion of very high temperatures by superheated steam because most of the heat losses from the steam are prevented while the steam is entering the cylinder. Experience has shown that in a reciprocating engine operating at high piston speed, the steam; enters the cylinder and expands in a very small fraction of one second. When highly superheated steam is employed only a very small amountof the steam adjacent the cylinder barrel will have time to cool and condense. The resulting loss in mean efiective pressure on the piston is very small as compared with the great lossof mean. efiective' pressure resulting from condenation. in. the conventional reciprocating engine using. saturated. steam;

While the-drawings. show the invention applied: to-an. engine of-theztype' shown. in Figure 1, it will ofi course; be understood. that the invention can be. usediwith o'ther' types: of engines-such as the single: acting: engine? as. well: as in. cylinder con-- structions embodying two or more cylinders in: onecylinder block.

It is: thought from, the foregoing description that the. advantages and novel features of the invention will be? readily? apparent.

It is" to beunderstood that changes may be made in'zthevconstruction and in the combination and arrangement? of the several parts provid'edi that: such: changes; fall. with" in the. scope" ofi the appended claims:

I claimz.

1'. Inaisteamz engine-of. the reciprocating piston" type; having. a cylinder;. a. piston: mounted. for? reciprocation, a piston rod projecingi from. one? end of the cylinder, and an intake valve at: oneend: thereof, a cylinderhead for the end of the cylinder through: which the piston. rod projects saidi cylinder head": having: an opening. for the piston rod and another. opening: in alignment: with the: corresponding intake port; the cylinder? head:havingx'aiwater jacket chambersurrounding. both. openings: andseparated' from them: by walls; of: substantially uniform thickness and an opening at each' end of'the Water jacket chamber for? the admissionaandzdischarge' ofza cooling medium; whereby: the metal enclosing: the" piston rod and the' intake: valve will be cooled in succession. by a. cooling medium flowing through the'water jacket; chamber..

2 Inasupeitheated steam: engine of the reciproeating; piston type, having a cylinder, a piston; mounted for. reciprocation; a: removable. cylinder head: for" one; enda of" the: cylinder,. and. an: intake:

valve opening; in: the cylinder head, the: cylinder head having aiwater jacket: chamber. of. an ex:- tended? area,- concentric: with; the cylinder,. said chamber: surrounding: the intake: valve. opening, whicliis separatedtherefromzby a- Wall ofuniforn'r: thicknesshthezwall of the cylinder head'having an inlet opening and outlet: openingsv at opposite endsof the water jacket chamber, whereby a" cooling liquid will? flow the entire length of. the-- water jacket space and completely surround the inlet-valve opening;

HARRY M. ARNOLD.

(References on following page) REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Jamieson Dec. 18, 1877 Schmidt Aug. 11, 1914 Stumpf Oct. 5, 1915 Daiber et a1. Nov. 9, 1915 Metcalfe Feb. 14, 1922 Number Number France Apr. 20, 1931

Images