US2408800A

US2408800A - Engine

Info

Publication number: US2408800A
Application number: US319851A
Authority: US
Inventors: Andre J Meyer
Original assignee: MAWEN MOTOR CORP
Current assignee: MAWEN MOTOR Corp
Priority date: 1940-02-20
Filing date: 1940-02-20
Publication date: 1946-10-08
Anticipated expiration: 1963-10-08

Description

A. J. MEYER ENGINE File@ Feb. 2o, 17940 e sheets-sheet 1 oci 3 w46 A.v J. MEYER 2,408,800 l ENGINE Filed Feb. 2o, 1940 e sheets-sheet 2 A. J. MEYER ENGINE 6 Sheets-Sheet 3 Filed Feb. 20, 1940 vm E M lm A.

ENGINE Filed Feb. 20, 1940 6 Sheets-Sheet 4 TOR ATTORNEY Ud. s, i946.

A. -J. MEYER ENGINE FiledFeb. 20, 1940 6 Sheets-Sheet 5 um @a E945 i A.VJ. MEYER 2,408,800

ENGINE Filed Feb. 20, 1940 6 Sheets-Sheet 6 Pateniea oci. s, 194e 2,463,800

UNITED STATES PATENT OFFICE ENGINE Andr J. Meyer, Lexington, Ky., assigner to Mawen Motor Corporation, New York, N. Y., a corporation of Delaware Application February 20, 1940, Serial No. 319,851

39 Claims. l

This application is a continuation-in-part with respect to my copending application Serial No. 194,020, led March 5, 1938.

The present invention relates to engines and has particular reference to slide Valve engines of the kind in which the flow of cylinder gases is controlled by relative rotary motion between one or more cylinders of a cylinder bank and a ported valve member with which ports at the outer ends (Cl. 12S-44) with the accompanying drawing forming a part hereof, in which there is described and illustrated diierent suitable forms of construction :for applying the principles of the invention to different kinds of engines.

In the drawings:

Fig. l is a more or less diagrammatic section, partly in elevation, taken on the central transverse plane of the cylinder bank of a radial enof the cylinder register. Still more particularly, 1o gine embodying the principles of the invention; the invention relates to internal combustion en- Fig. 1a is 4a section taken on the line I a--ia gines of the kind in which there is relative roof Fig. 1; tary motion between a cylinder bank having Fig. 1b is a section showing a different form of cylinders arranged in radial or star arrangement part of the structure shown in Fig. l; and a circular ported valve member. Still more l Fig. 2 iS a longitudinal SeCtiOn On enlarged particularly, the invention relates to the last scale of the structure shown in Fig. 1, taken along mentioned type of engine in which the valve memn the line 2-2 of Fig. 1I ber is in the form of an annulus encircling the Fig. 3 is a View on still larger scale of a part of outer ends of the cylinder. the structure shown in Fig. 1;

In engines of the kinds noted above, one of Fig. 4 is a section taken on the line 4-4 of the major problems in the production of a com- Fig- 3; mercially satisfactory engine is that of obtaining Fig 5 iS a SGCOH taken 0n the 1111 5 5 O and maintaining a satisfactory seal between the Fig. 3; valve and the cylinder, which seal will operate Fig. 6 is a section showing a diierent embodito eiectively prevent leakage of gas between these ment 0f Sealing means applicable t0 an engin parts and which will also permit adequate lubriof the kind showninFig. 1; cation to be maintained at all times between the Fig. '7 is a plane view taken along the line '1 -'l parts which move relative to each other in slidof Fig. 6; ing relation. Fig. 8 is a diagram illustrative of variations in Heretofore it has been proposed to eiTect the sealing lm pressure obtained in accordance with desired seal between cylinders and valve through the invention; the medium of annular sealing elements of cuff- Fig. 9 is a diagram illustrating the variations in like form carried by the cylinders so as to be sealing film pressures obtainable with sealing elemovable relative thereto and having sealing faces ments having different plOpOrtiOnS; adapted to slide relative to a circular valve truck, 3 Fig. 10 S'a Central l0ngitudinal Section 0f a barthe surface of which is shaped to mate in sealrel type engine embOdyng the principles 0f the ing contact with the sealing faces of the sealing invention; elements. In such arrangements means is also Fig. 11 is a Section taken 0n the line ll-ii 0f provided for closing the valve ports when they are Fig. 10; not in registry with the cylinder ports, such means 4o Fig. 12 is a fragmentary SeCtiOn 0n enlarged being carried by the cylinder bank to have relative scale showing part of the structure illustrated in rotary movement with respect to the valve mem- Fig. 10; ber and to be in sliding sealing contact with the Fig. 13 is a View taken on the line I3-l3 of valve track. Fig. 12;

It is the general object of the present invention 4o Fig. 14 iS a View taken 0n the line 4|4 0f to improve upon prior constructions for engines Fig. 10; of the kind under consideration, by the provision Fig. 15 is a section on enlarged scale taken on of improved sealing means-` as will hereinafter the line |5l5 of Fig. 11; and more fully be pointed out. Fig. 16 is a fragmentary plan view of the de- For an understanding of the more detailed natails shown in Fig. l5. ture and objects of the invention, the manner Referring nOW more lDaIiCUlariY t0 Figs. 1 and of its application to dii-ferent specic forms of 2, the general type of engine construction therein engine and the advantages to be derived from its illustrated is known and comprises a bank of use, reference may best be had to the ensuing porradially arranged cylinders IB, ve being shown tion of this specication, taken in conjunction in this particular embodiment. It will be understood that the number o cylinders employed in the bank may be varied and also that the engine may comprise one or more banks of cylinders. Since in so far as the present invention is concerned the novel structure would be essentially the same for different banks, in the case of a multi-bank engine, it is suicient to describe but one.

Cylinders l are provided with pistons l2 which are connected to the crank pin le of crankshaft I6 by means of a master connecting rod I8 connecting one of the pistons with the crank pin and a series of rods 2E) connecting the remaining pistons with the big end of the master rod i8'.

The cylinder bank is encircled by an annular valve member 22, the details of which will be more fully described later and the engine is so construct-ed that there is relative rotary movement between the cylinder bank and this valve member. This rotary movement may be with the valve member rotating or stationary. In the present instance the valve member is stationary and the cylinder bank and crankshaft are caused to rotate in opposite directions in properly timed relation through suitable gearing. In the embodiment illustrated the valve memberV 22 is carried by the stationary structure indicated generally at 2d, which also carries the power output shaft 2S on which a propeller may advantageously be mounted. with gear 3B splined to the crankshaft and also carries gear 32 which meshes with an idler vgear 3'4 (Fig. l) mounted in the xed housing structure. Gear 3d meshes with gear 36 which is attached to the rotatably mounted crankcase structure 38 carrying the cylinders l0; Due to the employment of the idler gear 34 the cylinder bank and the crankshaft will be caused to rotate n opposite directions and the proper timing is secured by selection of suitable gear ratios between gears 28 and 3B on the one hand and gears 32 and 36 on the other hand.

Aside from the specic gear arrangement involving the use of a geared-down power output shaft, which per se forms no part of the present invention, the general type of engine construction is known and is not believed to require further detailed explanation herein for an understandingof the present invention The valve 22 is provided at suitably spaced intei-vals with inlet ports 4D and exhaust ports 42 with which the cylinders are adapted to successively register in their movement relative to the valve. The valve is further provided with an inner sealing surface or track 64 which in the present embodiment, as will be seen from Figs. 1 and 2, is spherically curved. In so far as the principles of the invention are concerned, the surface of the valve track may be of other conguration, such as cylindrical or conical with respect to the axis of relative rotation between the valve and the cylinders, as is known in the type of engine under consideration. In other forms of engines, as will hereinafter more fully appear, the valve track may be a plane disc.

Each of cylinders i3 is formed to provide a port :l at its outer end for ilow of gases to and from the cylinder, the walls of the port forming a cylindrie-al bore 48 for the reception of a sealing element 5D. Sealing element 50 is of cuff-like form and comprises a barrel portion 52 and an outer flange portion 54, the outer surface 55 of which is spherically ground to match the inner surface of the valve.

For bridging the space between adjacent seal- Shaft 26 carries a gear 28 meshing ing elements, in order to seal the valve ports when the cylinder ports are not in registry therewith, an annular shoe 58 is provided, the outer surface 60 of which is also spherically curved to match the inner sealing surface of the valve. As will be observed from Fig, l, the shoe 58 is integral around the entire periphery of the engine and this shoe is advantageously of one piece constructionl It is provided at suitably spaced intervals with circular openings 52 through which the ilange portions of the sealing elements project to come into sealing contact with the inner surface of the valve. As will be observed from Fig. 3, the sealing elements have a close sliding t in openings 62 and a seal is advantageously provided between the shoe and each of the sealing elements by a ring te. A seal is also provided between each cylinder structure and its cooperating sealing element by means of a series of rings EG carried by the barrel portion of the sealing element and it is to be noted that substantially greater clearance is provided between the cylinder and the barrel portion of the sealing4 element, as shown somewhat exaggeratedly at e3, than is provided between the flange of the sealing element and the walls oi the opening 62.

The shoe 58 is carried with the cylinder bank and in the embodiment illustrated the connection between cylinder bank and the shoe is established between the shoe and the radially outer part of one of the cylinders, indicated at I 0a. In the embodiment illustrated, a ring 'l0 encircles the neck of the cylinder and is held in place by a light snap ring 12. Ring l0 is provided with lugs lll for a pivot I6 on which is pivotally mounted a threaded pin l. Pin '18 is connected to a second threaded pin Si) by means of a threaded sleeve 82 held in adjusted position by a suitable lock nut S4. Fin is pivoted by means of a suitable Divot pin 8S to the shoe 53. In the embodiment illustrated the shoe 58 is of one piece construction and advantageously may be of relatively light metal. For ease of manufacture and like reasons, this shoe is advantageously turned symmetrically and in order to provide the desired connection, an insert 88 is advantageously xed to the shoe, the insert carrying suitable lugs 9D for mounting the pivot pin 8S.

The threads on the two

pins

18 and 80 are formed with different pitch so that by turning sleeve 32 the length of the connection between the cylinder and the shoe may be varied and the latter adjusted peripherally with respect to the cylinders.

The sealing elements 5G are held in contact with the valve by means of a series of coil springs 92, the inner ends of which are advantageously held in spring retaining cups 94 seated in bored out recesses in the cooling iins 98. At their outer ends, the springs 92 bear on the inner face of the flange portion of the sealing element.

As will be observed from Figs. 3 and 4, the bore 98 through each sealing element is eccentric with respect to the outer surface I! of thebarrel portion of the element and the sealing elements are advantageously provided with notches D2 for the reception of locating pins 104 mounted in the shoe 58. Notches |02 are wider peripherally than the locating pins so as to permit the sealing elements to have a limited amount of rotational movement relative to the parts with which they are in contact.

The general operation of the engine is well known and need not be described in great detail. In the engine shown, which is of the four-stroke cycle type, the cylinders, revolving within the stationary valve ring, draw charges into the combustion chambers through the inlet ports di), compress the charges and re them either through heat of compression or by any suitable ignition means such as a spark, and exhaust the gases through the ports 42.

During operation of the engine the pressure of the working gases is maintained in the cylinders primarily through the medium of the sealing elements 5 and in order for such sealing to be most effective, these elements must seat properly against the inner face of the valve 22. Obviously, in view of the sliding contact relation between the parts, the spherically curved surfaces must be lubricated and for the best results to be obtained the sealingrelements should, when the engine is in operation, tilt very slightly so that a wedge-shaped oil film is formed between the outer face 56 of the element and the inner face All of the valve, this lm being wedge-shaped in the plane of rotation of the cylinder bank and thicker at the forward or leading edge of the sealing element than at the rearward or trailing edge thereof. It will be understood of course that the variation in thickness of the oil film is in practice very minute but any variation o1" this character should always be such that the oil film is thicker at the leading than at the trailing edge of the sealing element. If the opposite 'were true, the leading edge of the sealing element would operate as a scraper tending to cut through the oil film and produce substantially dry metal to metal contact between the relatively sliding parts.

In prior forms of construction where sealing elements of the kind hereinbefore described have been employed, this latter and undesirable con dition has occurred primarily, it is believed, because of the fact that the sealing elements have been carried by the cylinders in such manner that friction between each sealing element and the valve face or track has produced a force couple tending to tilt the sealing element in a direction such that the leading edge is radially further out than the trailing edge. The reason for this it is believed will be evident from a consideration of Fig. 3, assuming for the moment that there is substantial clearance between the sealing element and the shoe 58. In such case, friction between the sealing element and the valve tends to move the outer'end of the sealing element to the right as viewed in Fig. 3, assuming the direction of rotation of the sealing element relative to the valve to be as shown by arrow I 06. At the same time, tangential force is transmitted to the barrel portion of the sealing element from the neck of the cylinder in a direction opposing the frictional force, but since these two forces are offset, the resulting tendency under such conditions is for the sealing element to tilt in a manner which in e'ect makes an oil scraper of the leading edge of the-element.

In accordance with one phase of the present invention, this condition is eliminated through the provision of the connection between the cylinder bank and shoes 58 and the contact between the shoe and the flange of the sealing element which operates to center the sealing element with respect to the cylinder and which applies force to the sealing element opposing the. frictional force at the same radius as that at which the frictional force is applied. Consequently, there is no unbalanced force couple produced by the frictional force and tending. to cause the element to tilt in undesired direction. Further, the centering of the barrel portion of the sealing element with respect to the bore in the neck of the cylinder and the provision of substantial clearance between these parts permits the fullest possible freedom of action of the sealing rings at this point and minimizes the possibility of sticking. This of course all contributes to the desired freedom of movement of the sealing element toward and away from the valve track which is a highly important factor in the main-` tenance of an effective seal.

By means of the adjustment provided by the connection between the cylinder bank and the shoe 53, it will be evident that the sealing elements can readily be centered accurately with respect .to the cylinders.

As previously noted, it is desirable to have the sealing elements tilt slightly during normal operation to provide a wedge-shaped oil film space between the sealing surfaces, with this wedgeshaped space opening forwardly in the direction of relative rotation of the sealing element with respect to the valve. In accordance with another phase of the present invention, this tilting action in the desired direction is positively provided for by producing a positive force couple acting counter to the force couple produced by friction between the relative sliding surfaces.

The force couple positively provided is secured by establishing a relation between the resultant pressure acting on the element and the contact area of the sealing face ofthe element such that the center of the resultant pressure tending to forcethe element against the valve member is behind the center of gravity of the contact area of the element, when considered in the direction of relative sliding movement of the sealing element.

It will be apparent from a consideration of Fig. 3 that during the compression and working strokes of the cycle, the 'sealing elements are subjected to substantial values of unbalanced gas pressure due to such pressure acting on the eX- posed inner ends of the barrel portions of the elements, which pressure tends to force the elements radially outwardly again-st the i valve member.

This pressure may advantageously be employed to cause the center of pressure acting on each element to be located at a place diiferent from the center of gravity of the contact surface of the element, and in the present embodiment this is accomplished by making the bore of the element eccentric.

As will be apparent from Fig. 4, the center of pressure acting on the element due to gas pressure will, due to the eccentric bore, lie behind the central axis of the element, because of the greater area of end surface exposed to gas pressure behind the transverse plane passing through the axis, as compared with the area ahead of such transverse plane. Since the unit pressure acting on the inner end surface of the element due to gas pressure is uniform, the center of pressure resulting from gas pressure 'will coincide with the center of gravity of this area.

The eccentric bore will also shift the center of gravity of the annular contact surface 55 as cornpared with the center of gravity of the contact surface of a like sealing element having a concentric bore. This shift of the center of gravity of the contact surface will also be to a point behind the transverse plane passing through the central axis of the element. In other word-s, the eccentric bore will operate to shift the center of pressuredue to gas pressure rearwardly, and willfalso operate to shift the center of gravity of the contact surface rearwardly from the positions these centers would have for a concentric bore. However,l due to the fact that vthe eccentricity of the bore operates to shift a'larger proportion of the total area of the pressure surface than of the total area of the contact surface, the shift of position of the center of pressure resulting from making the bore eccentric is greater than the shift of the center of gravity of the contact surface resulting from such eccentricity. Consequently, with the bore made eccentric in the manner indicated, the center of pressure due to gas pressure lies behind the center of gravity of the contact area.

The eccentricity of thebore also results in eccentric loading of the element due to centrifugal force, and this eccentricity of the loading due to centrifugal force operates to produce a condition such that the center of pressure of the centrifugal force acting on the sealing element is also behind the center of gravity of the contact surface.

The resultant force acting to maintain the sealing element in contact with the valve track is produced by three factors in the construction shown, these being the forces due to gas pressure, centrifugal force, and the force exerted by the springs. Of these the force due to gas pressure is much greater than the others, particularly during the compression and working strokes when sealing pressure is desired.

The eccentric loading due to centrifugal force is useful in aiding to maintain the desired condition in which the center of pressure lies behind the center of gravity of the contact area during the suction stroke of a four-cycle engine, which if not supercharged, produces some degree of subatmospheric pressure in the cylinder during this stroke,with resultant negative pressureon the inner end surface of the sealing element. The centrifugal force, however, varies with the square of the speed of rotary movement of the cylinder bank and at low or idling engine speedsfis not a material factor. Also, as will hereinafter appear, centrifugal force is not a factor productive of sealing pressure in certain forms of application of the invention.

In order, therefore, to take care of idling speed conditions or other conditions which eliminate centrifugal force as a factor productive of sealing-pressure and also to take care Vof conditions productive of negative force due to gas pressure, the springs tending to produce a sealing pressure are employed. The spring load, however, is advantageously relatively very small as compared 'with the load due to gas pressure and for practical reasons it is usually most desirablertohave the springs of uniform strength-in order to eliminate any possibility of having the spring -load improperly applied due to mistakes in assembling.

From Figs. 3 and 4 it will be observed that the eccentric bore in the sealing elementresults in unequal areas of friction contact between sealing element and valve on the two sides of a plane coinciding withthe transverse diameter of the outer circumference of the sealing surface of the element. Obviously, this unequal distribution of the friction contacting surface will tend to cause the sealing element of its own accord ,to maintain the position indicated in these. figures in which the eccentric loading is-such-thatboth `centrifugal force and gas-pressure are greater'on 8 the trailing side ofthe element than on the leading side.

Because this unequal distribution of the friction contact surface tends to cause the sealing element to maintain the correct position when the engine is in operation, the locating pin |04 is not essential, but the use of such pins is ad vantageous in order to prevent improper assembly of the sealing elements in incorrect positions of rotation from which they would have to be turned to their correct positions under the influence of forces due to friction generated only after the engine is put into operation.

As previously noted, the positive force couple for producing the desired tilted condition which results in the formation of a forwardly opening wedge-shaped space for the oil film is secured by locating the center of pressure acting to force the sealing element into contact With the valve surface behind the center of gravity of the area of sealing surface in contact with the valve surface.

If the above general condition is met, the desired positive force couple will be produced and a further effect will also be produced which is highly advantageous, as will be explained more in detail later, in the maintenance of a proper seal at all times in engines wherein ignition devices, fuel injection devices, or any other auxiliaries are located in recesses or pockets in the valve member in positions to be passed by the sealing elements.

In the embodiment previously described, the condition of the center of pressure being offset with respect to the center of gravity of the sealing surface is accomplished by the use of an escentric bore through the sealing element. This condition may, however, ber obtained in a variety of different ways and in Figs. 6 and 7, another embodiment of sealing element structure is illustrated by means of which the desired offsetting of the center of pressure with respect to the center of gravity of the sealing area is advantageously obtained.

Referring,r now more particularly to these'igures, the sealing element lli! is provided with a bore H2 which is concentric with the bore H4 in the cylinder. The flange portion H6 of the element is, however, made eccentric with respect to the axis of the barrel portion of the element and the eccentricity is such that the center of gravity of the sealing surface H8 is located ahead of the axis of the barrel portion of the element. Since the flange is eccentric with respect to the axis about which the sealing element can turn in the cylinder, the sealing element will be held against turning from its proper position by the correspondingly eccentric opening in the sealingr shoe I2!! through which the element projects. In order to avoid any possibility of improper assembly due to improper positioning of the sealing shoe circumferentially `with respect to the cylinder bank, a locating pin |22 may be einployed, as in the embodiment previously described.

From Figs. 6 and 7 it will be apparent that in the present embodiment the sealing element is concentrically loaded in so far as gas pressure is concerned, which is the major pressure producing factor to be taken into consideration, and if it is assumed that the spring load is uniform, as is most desirable, the center of the resultant pressure coincides with the axis of the barrel portion of the element. Due to the eccentricity of the flange, however, the center of gravity of the sealing surface is ahead of the axis of the barrel portion, which gives the desired condition of the center of pressure lying behind the center of gravity of the sealing area. In the present form of sealing element, a substantial offsetting of these two factors with respect to each other is in many instances more readily obtainable than by the use of an eccentric bore. When an eccentric bore is employed, both the center of pressure and the center of gravity are moved as compared with a concentric element and the amount of oiset is determined by the difference between the respective amounts of displacement of these tvo factors as compared with a concentric element. In the present instance, the eccentricity of the flange affects the position of the center of gravity of the sealing surface without affecting the position of the center of pressure resulting from gas pressure, as compared with a concentric element, and

consequently, a given amount of eccentricity of f the flange will in the present embodiment result in a greater displacement of the center of gravity of the sealing area relative to the center of pressure than is the case when the bore is made eccentric.

Regardless of the specic manner in which the center of gravity of the sealing area is located ahead of the center of pressure, the effect, as will be understood from well established laws of mechanics, is toy produce a uniformly variable pressure between the sealing surface of the element and the valve surface, such uniformly variable pressure increasing in value from a minimum pressure at the leading edge of the element to a maximum pressure at the trailing edge. This uniformly variable pressure is rellected in a like `uniformly variable pressure of the lm of lubricant between the relatively sliding surfaces and in order to maintain this lm unbroken under all conditions of operation, the variation in the lm pressure is made use of in accordance with still another phase of the invention to overcome certain conditions tending to displace the nlm of lubricant which provides the' actual seal.

In Figs. 6 and 1b, structures have been shown for spark ignition engines in which a high tension spark plug |25 of conventional form is shown mounted in the valve member to be passed by the cylinder ports in order to effect ignition. In mounting such a plug or any other form of ignition or other auxiliary device (such as an injection nozzle in the case of an injection engine) it is substantially impossible in a practical construction to construct and locate the auxiliary device in the valve member so that the valve surface is entirely flush and a pocket such as is indicated at IES is avoided.

The presence of any pocket such as that indicated at 26 produces a condition tending to force the sealing element away from the valve, when the sealing element is in a position relative to the pocket such as that shown in Fig. 6. With the sealing element moving relative to the valve in a direction indicated by arrow |28, the cylinder port has just passed the ignition point and the charge in the cylinder has been fired to produce high combustion gas pressure. Subsequent to ignition and before the cylinder moves out of communication with the ignition device, the pocket 26 has become lled with gas at combustion chamber pressure and is filled with gas at this pressure as the relative movement causes it to move to a position over the trailing portion of the sealing surface of the element.

When combustion takes place and high pressure is generated in the cylinder, the high pressure gases try to force their way past the sealing element around the entire periphery of the bore H2. To escape at this point, however, the gases must force the oil lm away from the bore H2 for a considerable distance before blow-through can occur and the area exposed to gas pressure is extremely small, being merely the edge of the oil film at the circumference of the bore. The time element in normal engine operation is extremely short and it has been found from experience that a seal which will prevent blowthrough from the circumference of the bore in the sealing element can successfully be maintained with a nlm pressure which is very materially lower than the gas pressure developed in the cylinder. From the standpoint of the friction developed in the engine it is, of course, desirable to maintain the lowest practical pressure loading on the element and the relatively low pressure which will eifect a seal around the perimeter of the bore of the element is, of course, advantageous.

An entirely different condition, however, is presented when. an ignition or other pocket lled with gas at cylinder pressure passes to a position over a part of the sealing surface of the element. In this case a substantial area is exposed to gas pressure and the tendency of the high pressure pocketed gas is to mushroom out across the sealing surface in a way which tends to force the element away from the valve track. Actual test experience has demonstrated that when the loading pressure and the resultant film pressure is too low on the trailing side of the element, the pressure of pocketed gases in an ignition pocket will force the element away from the valve track.

Experience has further shown that in order to maintain the sealing element in constant contact with the valve surface and to maintain the desired seal under all conditions, the loading on the element must be such as to produce a film pressure at the place passed by any gas filled pocket which is at least substantially equal to the maximum gas pressure developed in the cylinder and consequently in such pocket. From the standpoint of avoiding scraping action by the leading edge of the element it is desirable, on the other hand, to have the minimum practical loading pressure upon the element at this edge.

It will therefore be seen that by placing the center of gravity of the sealing area ahead of the center of pressure, so that the lm pressure increases from the leading toward the trailing edge of the element, two highly important conditions are met, the rst being the production of the force couple tending to tilt the element in the proper direction, and the second being the production of the variable nlmy pressure which produces relatively high film pressure at the trailing side ofthe element Where it is essential to have it in any case where an ignition or other pocket exists, while at the same time a desirable relatively low film pressure is produced at the leading side of the element.

The ideal theoretical condition, in so far as the leading edge is concerned, is zero nlm pressure at this point. but for various reasons this condition difficult if not impossible to attain with a sealing element proportioned to meet other practical conditions.

Experience has shown that satisfactory operation can be secured when the sealing element is so constructed that the average lm pressure at the leading portion of the sealing surface is l1 of the order of one-half or somewhat less of the gas pressure developed in the cylinder while the average ilm pressure at the trailing portion of the sealing surface which is crossed by any gas lled pocket is ci the order of the cylinder gas pressure.

This condition may be produced by an almost infinite variety of different specic designs of sealing element depending upon the relation between the inside and outside diameters of the barrel portion, the diameter of the flange portion and the extent to which these various diameters are made eccentric with respect to each other.

Within practical limits, substantially any desired condition and any desired rate of increase of nlm pressure from leading to trailing edge of the element may, however, be secured by properly relating these variables. While to secure any desired values of nlm pressure and any desired variations thereof from leading to trailing edge of a sealing element may be calculated mathematically, such calculation is relatively intricate in nature and in order to provide the reader with a ready means of determining the relations necessary to secure the desired character of film pressure, the relationships required to secure desired film pressure characteristics for a cuff of the eccentric iiange type shown in Fig. 6 are shown by way of example in Figs. 8 and 9.V

Referring to Fig. 8, ,-1 is the radius of the bore of the sealing element, rz is the radius of the eccentric scaling surface, and r3 is the radius of the cylinder bore in which the sealing element is mounted. Since in the form illustrated the element is concentrically loaded by gas pressure, the axis of the center of pressure is located at :c which is the center of radii r1 and r3. The cen ter of gravity of the sealing surface is located at yl, the offset between the center of pressure and the center of gravity being represented by distance c. In the design shown, the radius ri of the bore of the element is three times the wall thickness of the barrel portion of the element represented by (r3-ri). This represents a good practical relation between port diameter and wall thickness of the element. Also, for practical reasons, the design is based on an offset of the center oi the radius r2 from the center of the radius r3 such that the circumference of the sealing surface at the trailing edge of the element is tangent to the outer circumference of the barrel portion of the element.

The line a represents graphically the slope of the variable iilm pressure from zero Value at point n at the neutral axis, and the Vectors pi, pz, pi, and pz represent the nlm pressures at the edges of the sealing surface to which they are respectively tangent.

Fig. 9 illustrates graphically the film pressures obtainable for diierent ratios of radii in terms of cylinder gas pressure. In this diagram the abscissae represent the ratio and the ordinates represent film pressure in terms of percentage of cylinder gas pressure. The curves p1, p2, p3 and ir4 represent the pressures obtained at the points on the sealing surface to which the correspondingly numbered vectors are tangent in Fig. 8.

As previously noted, a satisfactory condition for lm pressure has been found to be one wherein the pressure across the trailing portion of the element passed by a gas iilled pocket in the valve member is 100% of gas pressure and by reference to Fig. 9 it will be seen that if the ratio ci 1.47, the lin pressure at the trailing edge pz is 04% of cylinder gas pressure and at p4 it is 98% i such pressure, the average across the surface roin pi to p2 being slightly over 100% of gas pressure. With this ratio of the film pressure at the leading edge pi is only of pressure and at point p3 it is 50% of pressure, the average lm pressure across the leading -portion of the surface thus being 421/295. Thus, for the above described type of eccentric ange cuff, a ratio for of 1.47 provides a degree of slope for the variably increasing film pressure from the leading to the trailing edge which produces Values of nlm pressure that have been found to be satisfactory for maintenance of the sealing iilm in engines having pockets in the valve member which are periodically llled with high pressure gases and which tend to force the sealing element away from the valve surface. Diiferent specic engine designs may, for best practical results, re-

quire different relations between film pressures at the leading and trailing edges of the sealing surface, but as will be apparent from the diagram of Fig. 9, substantially any relation between these pressures may readily be attained by properly proportioning the radius rz to the radius r1 for any basic proportion of radius ri to radius r3. For example, if the ratio is made 1.353 (with the assumed basic design in which r1 equals three times (Ti-r3), the element becomes concentric and the film pressure at the leading and trailing portions of the element is he same. t the other extreme, for an engine which for any reason does not require a film pressure equal to gas pressure on the trailing side of the element, the nlm pressure at the leading side may be made very materially less than half the gas pressure. By reference to the chart of Fig. 9, it will be seen that if at the trailing side of the element an average lm pressure equal to only 92% of the gas pressure is adequate, an average nlm pressure at the leading side of the element of as little as 25% of gas pressure may be obtained through use of a design in which the ratio It is believed it will be evident that in so far as the loading of the sealing elements and the provision of the variable film pressure of desired character are concerned, it is immaterial whether the sealing surfaces are straight or curved in a plane normal to the axis of relative rotation and consequently in so far as these features are concerned, the relatively sliding surfaces may be spherical, cylindrical or conical, as may be dictated by other considerations.

Furthermore, the invention is not limited in its application to engines of the kind just described, in which the valve and sealing element surfaces are curved, 4and its application to an engine of different character is illustrated in Figs. 10 to 16,

l to which reference will now be had.

Referring now more particularly to Fig. 10, the invention is shown applied to a bi-rotary engine of the kind in which one or more cylinder banks are arranged with the cylinders of each bank arranged in a circle and with their axes parallel to each other. This type of engine is ordinarily referred to as a barrel type. In this form the reciprocating motion of the pistons is usually transmitted to a central shaft parallel to the cylinder axes and having relative rotary movement with respect to the cylinders, through the medium of a cam or swash plate forming a part of the shaft, or equivalent mechanism, Since the shaft in such an engine is functionally equivalent to a crankshaft of conventional form, in so far as the present invention is concerned, it

will be understood that the term crankshaft as employed herein is intended to include all forms of shaft performing the oiiice of an engine main shaft to which the forces from the pistons are transmitted.

The engine shown in the present embodiment comprises two opposed cylinder banks. The construction of these banks is the same and for the purpose of understanding the use of the present invention in this kind of engine it will be suincient to describe in detail only one of these banks I and its associated Valve structure.

The cylinder bank 200 comprises a cylinder block which advantageously may be an integral casting providing a plurality of cylinders 222. In the present instance, seven such cylinders are shown. In the embodiment illustrated, the cylinders are cooled by means of fins 2i!!! which also serve as means for connecting the several cylinder barrels. The cylinder bank is mounted to rotate about a central crankshaft 22S having a swash plate or cam 29S thereon which coacts with rollers 2|@ mounted on pins 2|2 in pistons 2M which reciprocate in the several cylinders. In the engine shown, a second cylinder bank 2|6 is provided and the pistons 258 for the cylinders 22S] of the second bank lare advantageously made in one piece with pistons 2M. and carry rollers 222 cooperating with a cam surface on the side of the cam plate or crank 20B opposite that which cooperates with the rollers 2 lil.

The housing or mounting structure for the engine includes a valve member for each cylinder bank, the one cooperating with the cylinder bank 20) being indicated generally at 22d and the two valve members being axially held together by means of a series of axially extending tie rods or bolts, indicated at 226.

As in the engine previously described, the crankshaft, the cylinder bank, and the housing structure are interconnected by gearing to provide for relative rotation between these several components, and in the present arrangement this gearing comprises a planetary system including a sun gear 226 fixed to shaft 222, a series of planet pinions 228 meshing therewith and mounted to i:

l233 to the cylinder block and, in effect, forming a part of the cylinder bank.

The valve member 224 provides a at circular sealing surface or valve track 223 through which a series of inlet and exhaust ports open, one of which ports is shown at 242. It will be understood that these ports are arranged in a circle and are peripherally spaced from each other to bring them into communication with the cylinder ports at properly timed intervals in accordance with the cycle of operation of the engine. Such port spacing will be readily understood from a description oi the previous embodiment and therefore need not be further treated in detail.

Each of the cylinders, as in the previously described embodiment, is open'at its outer end and carries a sealing element 244 having a flat outer sealing surface 226 in sliding contact with the valve track 229. As-in the embodiment shown in Fig. 8, the bore 248 through the sealing element is concentric, as will be seen more clearly from Fig. 12, and the flange providing the sealing surface is eccentric as is shown more clearly in Fig. 11. The sealing elements are forced outwardly against the valve track by means' of springs 253 located between the underside of the flanges on the elements and a part of the cylinder structure.

The sealing shoe 252 is in the form of a iiat disc held in contact with the valve track by means of suitable springs 25E- carried by a disc-like portion 255 of the cylinder block. The sealing shoe 252 is provided with suitably spaced circular apertures 258 through which the sealingelements project into sliding contact with the valve track. Advantageously, the sealing elements are located against improper assembly by means of suitable locating pins 26B engaging the sealing shoe and the flange portions of the sealing elements.

As in the previously described embodiments, the sealing elements are davantageously relieved of any lateral thrust due to friction between the sealing shoe and the valve track by the provision of an adjustable connection for transmitting the thrust due to such friction directly from the shoe to the cylinder block. This connection is shown in Figs. 15 and 16 in the embodiment illustrated comprises a disc 262 carrying an eccentric pin 254 which projects into a slot 265 formed in the face of the sealing shoe 252. Disc 262 is secured by means of bolt 258 to a worm-wheel member 2l!! mounted to rotate in a suitable aperture in the part 256 of the cylinder block and is positively prevented from turning relative to the member 219 by means of a tongue and groove or slot connection 212. The worm-wheel 27B is engaged by a worm 214 mounted in suitable brackets 216 attached to the exposed face of the part 256, the pitch of the threads being such that the worm is irreversible and the worm being adjustable by means of a slotted end 278 for the reception of a screw driver or other adjusting tool.

As will be apparent from the drawings, the thrust due to friction will be transmitted from the shoe through the eccentric pin and associated structure directly to the cylinder block. It will further be apparent that by means of the worm and the slotted connection, iine adjustment of the position of the sealing shoe in peripheral direction relative to the cylinders and sealing elements may readily be obtained, in orderd to properly center the apertures 252 in the shoe with respect to the bores in the cylinders which receive the sealing elements.

In operation, this type of engine, in so far as the present invention is concerned, is essentially the same as that which has previously been described. The gearingv between the cylinder' bank and the crankshaft causes these components to rotate in opposite directions, with the cylinder bank rotating at lower speed thanthat of the shaft, so that the cylinder ports formed by the sealing elements pass the valve ports at properly timed intervals. The sealing elements are arranged with the centers of their eccentric flanges ahead 0f the respective cylinder axes in the direction of relative rotation of the sealing elements with respect to the valve track, as indicated in Figs. 11 and 13, wherein the direction of such relative movement of the sealing elements is indicated by the arrow 236.

With the relative rotation in this direction, the resultant center of pressure tending to force the sealing elements into contact with the valve track lies behind the center of gravity of the Contact surface, and the desired force couple for tilting the sealing elements to provide a forwardly open wedge-shaped oil space will be produced.

As in the previously described embodiment, it is immaterial in so far as the present invention is concerned, whether the relative rotation is between a moving cylinder bank and a stationary valve member or between a cylinder bank and a valve member both of which rotate but at different absolute speeds. Because of practical considerations, however, such as the attachment of intake and exhaust manifolds and other auxiliaries, it is preferable to make the valve member a part of the stationary component on the engine.

While in the embodiment just described, the valve track surface has been shown as a plane radial surface, it will be apparent that in so far as the present invention is concerned, this specific form of surface need not necessarily be used. The surface may be conical or may be curved in transverse cross-section so as to present a toroidal surface, but because of its relative simplicity and ease of manufacture, a plane radial valve track surface is to be preferred.

In the embodiments illustrated, both the valve track and the sealing shoe have been shown as of one piece construction. rIhis construction is to be preferred not only because of the symmetry obtainable and the resultant relatively more even expansion and contraction characteristics of the parts, but also because the resulting continuous sealing surfaces aid materially in preventing leakage into the valve ports when they are not in communication with cylinder ports. If, as shown in the embodiment of Fig. l., the sealing surfaces are of the annular spherically curved form. the parts may be assembled by inserting the shoe into the valve with the planes of the two parts at right angles to each other and forcing the shoe in by distorting it and the valve slightly from their circular form. Calculations show that for the materials ordinarily employed in engine construction, this can be accomplished without stressing the parts beyond permissible values but if in any particular instance either one or both of these parts are unusually stiff, one side of the inner surface of the valve may be relieved as indicated at IDB in Fig. 1 to permit the shoe to be inserted.

From the foregoing it will be evident that the principles of the invention may be applied to a wide variety of specific forms of engine structure and accordingly the invention is ont to be considered as limited to the embodiments hereinbefore described by way of example, but is to be deemed to include all forms of construction falling Within the scope of the appended claims.

What is claimed is:

l. In combination, a ported valve member and a structure providing a ported working chamber, said valve member and said structure being mounted for relative movement with respect to each other, a hollow sealing element carried by said structure and having an end sealing surface in sliding contact with said valve member to provide a seal for fiuid flowing through said ports, said sealing element being subjected to force tending to move it outwardly relative to said structure into pressure Contact with said valve member, and said end sealing surface being shaped and located to have its center of gravity ahead of the center of pressure of the force tending to move the element into Contact with the valve member, when considered in the direction of relative movement of said structure with respect to the valve member.

2. In combination, a valve member having a valve track and a valve port opening through said track, a structure providing a ported working chamber, said valve member and said structure being mounted for relative movement with respect to each other, a hollow sealing element carried telescopically by said structure to provide a seal 'for fluid passing through said ports, said element being movable toward and away from said valve member and having an end sealing surface in sliding contact with said valve track, said sealing element being subjected to force tending to move it outwardly relative t0 said structure into pressure contact with said valve track and said end sealing surface being shaped and located to have its center of gravtiy ahead of the center of pressure of the force tending to move the element outwardly into contact with the valve track when considered in the direction of relative movement of the sealing element with respect to the valve track.

3. In combination, a ported valve member having a valve track and a port opening through said track, structure providing a ported working chamber, said valve member and said structure being mounted for relative movement with respect to each other, a hollow sealing element carried by said structure, said element having an end sealing surface in sliding contact with said valve track and a barrel portion telescopically mounted in the port opening of said structure whereby to have its inner end exposed to the pressure within said working chamber, the center of gravity of the area of said end sealing surface being ahead of the center of pressure exerted by the fluid in said chamber and tending to force the element into pressure contact with the valve track, when considered in the direction of the relative movement of the sealing element with respect to the valve track.

4. In combination, a valve member having a valve track and a port opening through said track, structure providing a ported working chamber, said'valve member and said structure being mounted for relative movement with respect to each other, and a holl w sealing element carried by said structure to provide a seal for fluid flowing through said ports, said sealing element having movement relative to said structure and an end sealing surface in sliding contact with said valve track, and means including said end sealing surface and a portion of said element exposed to the fluid pressure within said working chamber for establishing a force couple tending to tilt said element to form a wedge shaped space for lubricant between said sealing surface and said valve track, said space opening forwardly When considered in the direction of relative movement of the sealing element with respect to the valve track.

5. In combination, a valve member having a valve track and a port opening through said track, structure providing a ported working chamber, said valve member and said structure being mounted for relative movement with respect to each other and a. hollow sealing element carried by said structure to provide a seal for fluid flowing through said ports, said sealing element being mounted to have movement relative to said structure toward and away from said valve track, an end sealing surface in sliding contact with the valve track and a surface exposed to the pressure of fluid in said chamber tending to force the sealing surface into pressure contact with the valve track, said surfaces having areas relative to each other and being located relative to each other to establish contact pressure between said end sealing surface and said valve track of uniformly increasing value from the leading to the trailing portion of said end sealing surface due to pressure exerted on the element by fluid in said working chamber.

6. In combination, a valve member having a valve track and a port opening through said track,

structure providing a ported working chamber, L

said valve member and said structure being mounted for relative movement with respect to each other, and a hollow sealing element carried by said structure to provide a seal for fluid flowing through said ports, said sealing element being mounted for movement toward and away from said valve track and having an end sealing surface in sliding contact with the valve track and a surface exposed to fluid pressure in said chamber tending to force said end sealing surface into pressure contact with said valve track, the area of the last mentioned surface being proportioned and located relative to the area of said end sealing surface to produce a unit contact pressure between the valve track and at least a portion of said end sealing surface of at least approximately the unit pressure of the fluid in said working chamber.

7. In combination, a valve member having a valve track and a port opening through said track, structure providing a ported working chamber, said valve member and said structure being mounted for relative movement with respect to each other, and a hollow sealing element carried by said structure to provide a seal for fluid flowing through said ports, said sealing element being mounted for movement toward and away from said valve track and having an end sealing surface in sliding contact with the valve track and a surface exposed to pressure of fluid in said working chamber tending to force the element into pressure contact with the valve track, said surfaces having areas relative to each other and being located relative to each other to produce pressure contact between said end sealing surface and the valve track of substantially uniformly increasing value from the leading portion to the trailing portion of said end sealing surface, the value of the unit contact pressure at the leading portion being of the order of one-half the unit pressure in the working chamber and the value of the unit contact pressure at the trailing portion of said end sealing surface being of the same order as that of the unit pressure in said chamber.

-8. In an engine, a ported valve and an openended cylinder mounted for relative rotational movement with respect to each other, a hollow sealing element carried at the open end of said cylinder and having an end sealing surface in sliding contact with said valve, said sealing element being subjected to force tending to move it outwardly relative to the cylinder into pressure contact with said valve, and said end sealing surface being shaped and located to have its center of gravity ahead of the center of pressure of the force tending to move the element outwardly With respect to the cylinder, when considered in the direction of relative rotational movement of the sealing element.

9. In an engine, a ported valve and an open ended cylinder mounted for relative rotational movement with respect to each other, a hollow sealing element carried telescopically by the open end of said cylinder, said element having an end sealing surface in sliding contact with said valve and a barrel portion having its inner end exposed to the pressure of cylinder gases, the center of gravity of the area of said sealing surface being ahead of the center of pressure exerted by the cylinder gases and tending to force the element outwardly with respect to the cylinder, when considered in the direction of the relative rotational movement of the sealing element.

10. An annular sealing element for engines providing a surface for telescopic sliding mounting with respect to a cooperating cylinder surface and two opposed end surfaces, one of said end surfaces constituting a sealing surface for sliding contact with a valve track, the center of gravity of the area of said sealing surface being oset with respect to the center of gravity of the area of the opposed end surface, and the offset between said centers of gravity being such that the center of gravity of the sealing surface lies ahead of the center of gravity of the opposed end surface when considered in the direction of intended movement of the element with respect to the valve track with which it is to operate in sliding contact.

11. An annular sealing element for engines comprising a hollow barrel portion for telescopic sliding mounting with respect to a cylindrical cylinder pari; and a flange portion at one end of said barrel portion providing an end sealing surface for sliding contact with a valve, the center of gravity of said sealing surface being offset with respect to the center of gravity of the end surface of said barrel portion at the end of the element opposite said sealing surface, and the offset being such that the center of gravity of the sealing surface lies ahead of the center of gravity of the opposite end surface when considered in the direction of the intended movement of the element with respect to the valve with which it is to operate in sliding contact.

12. An annular sealing element for engines comprising a hollow barrel portion for telescopic sliding mounting with respect to a cooperating cylinder part, and a flange portion at one end of .said barrel portion providing an end sealing surface for sliding contact with a valve track, the flange portion and the center of gravity of the sealing surface provided thereby being eccentrically located with respect to the central longitudinal axis of said barrel portion.

13. An annular sealing element for engines comprising a barrel portion for telescopic sliding mounting with respect to a cooperating cylinder part, said barrel portion having a circular outer surface and a circular inner surface and a flange 19 portion at one end of said barrel portion, said flange portion providing an end sealing surface for sliding contact with a valve track and having a circular circumferential surface, the centers of at least two of said circular surfaces being offset with respect to each other.

14. An annular sealing element for engines comprising a barrel portionfor telescopic sliding mounting with respect to a cooperating cylinder part, said barrel portion having a circular outer surface and a circular inner surface concentric with said outer surface, and a flange portion at one end of said barrel portion providing an annular circular end sealing surface for sliding contact with a valve track, the center of said circular sealing surface being offset with respect to the center of the outer surface of said barrel portion.

15. An annular sealing element for engines comprising a, barrel portion for telescopic sliding mounting with respect to a .cooperating cylinder part and a flange portion at one end of said barrel portion providing an annular circular end seali ing surface for sliding contact with a valve track, said barrel portion having a circular outer surface concentric with the perimeter of said sealing surface and a circular bore extending through said sealing element, said bore being eccentric with respect to the outer surface of said barrel portion.

16; An annular sealing element for engines comprising a barrel portion for telescopic sliding mounting with respect to a cooperating cylinder part and a flange portion at one end of said barrel portion providing an annular end sealing surface for sliding contact with a valve track, said barrel portion having a circular outer surface and said end sealing surface having a diameter substantially larger than the diameter of said outer surface and a circular perimeter eccentric with respect'to and tangent to said outer circular surface.

1:7. An annular sealing element for engines comprising a :barrel portion for telescopic sliding mounting with respect to a cooperating cylinder part and a flange portion at one end of said barrel portion providing an end sealing surface for sliding Contact with a valve track, said barrel portion having a, circular outer surface and said end sealing surface having a diameter substantially larger than the diameter of said outer surface and a circular perimeter eccentric with respect to and tangent to said outer circular surface, said element having a circular bore extending therethrough lconcentric with said outer surl face.

18. In an engine of the character described, an open ended cylinder having a cylindrical bore, a sealing element having a barrel portion telescopically mounted in said bore and a ange portion at the outer end of said barrel portion, said flange portion providing an end sealing surface for cooperating with a valve track and having a circular perimeter eccentric with respect to the outer surface of said barrel portion, and a sealing shoe having a circular opening therein through which the flange portion of said sealing element projects intol cooperating contact with the Valve track said opening having substantially the same diameter as that ofsaid flange portion and being located eccentrically with respect to the axis of said-bore, said eccentrically disposed flange portion and opening cooperating toprevent rotation of the sealing element insaid bore.

19. In4 an engine., anannular ported valvemem ber having an inner sealing surface, a cylinder bank mounted within the valve member for relative rotation with respect thereto, said bank including a cylinder having an open outer end radially spaced from said sealing surface, an annular sealing member telescopically mounted with respect to said cylinder and extending beyond its outer end into sliding contact with said sealing surface, a sealing member in sliding contact with said sealing surface for sealing the valve ports when they are not in registry with a cylinder port, said sealing member being in tangential force transmitting relation with said sealing element closely adjacent to said sliding surfaces and being spaced from said cylinder to be out of tangential force transmitting contact therewith, and a connection between said cylinder bank and said sealing member for locating the sealing member rotationally with respect to the cylinder bank and for transmitting to the cylinder bank the tangential force resulting from friction between the sealing element and the sealing member on the one hand and the valve member on the other hand.

20. In an engine, an annular ported valve member, a cylinder bank mounted within said valve member for relative rotational movement with respect thereto, said bank including cylinders having open outer ends, annular sealing elements carried by said cylinders at their outer ends, said sealing elements being movable axially of their respectively associated cylinders and having end surfaces in sliding contact with the valve member to provide a seal, a peripherally continuous shoe for sealing the valve ports when the cylinder ports provided by said annular sealing elements are not in registry with the valve ports, said. shoe having openings therein through which said sealing elements extend into contact with the valve member and the edges of said openings being spaced from the outer ends of the respective cylinders, the outer portions of said sealing elements being in tangential force transmitting relation with said shoe, and a connection between said shoe and said cylinder bank for locating the shoe peripherally with respect to the bank and for transmitting to the cylinder bank tangential thrust developed by friction between the shoeand sealing elements on the one hand andthe valve member on the other hand.

2l. In anengine, an-annular ported valve member having an inner sealing surface, a cylinder bank mounted within the valve member for relative rotation with respect thereto, said bank including a cylinder having an open outer end radially spaced from said sealing surface, a sealing element telescopically mounted at the outer end of said cylinder, said sealing element having a flange at its outer end providing an end sealing surface in'contact with the sealing surface of the valve member, a sealing member having an opening? therein through which said sealing element projects, the flange portion of said sealing element being shouldered to provide an abutment with which the wall of said opening contacts to transmit tangential thrust from the sealing element to said sealing member, said flange portion further providing an annular flange portion located between the cylinder and said sealing member, a plurality of helical springs located between said abutment and the cylinder for forcing the sealing element radially outwardly into contact with the sealing surface of the valve member, andra connection between the cylinder bank and said sealing member for locating the connected 2l parts peripherally with respect to each other and for transmitting to the cylinder bank thev tangential thrust developed by friction between the sealing member and the sealing element on the one hand and the sealing surface of the valve member on the other hand.

22. In an engine, an annular ported valve member having an inner face providing a spherically curved valve track, a cylinder bank mounted within said valve member for relative rotation with respect thereto, said bank including a, cylinder open at its outer end, an annular sealing element having a cylindrical portion telescopically mounted with respect to a cylindrical part of the cylinder to permit movement of the sealing element axially of the cylinder, said sealing element projecting radially beyond the end of the cylinder and having a spherically curved end surface in sliding contact with said valve track, said spherically curved surfaces and said cylindrical surfaces permitting turning movement of the sealing element about its axis, and means engaging said sealing element to prevent the rotation thereof permitted by said cylindrical and spherically curved surfaces.

23. In an engine, an annular ported valve member having an inner face providing a circular valve track, a cylinder bank mounted within said valve member for relative rotation with respect thereto, said bank including a cylinder open at its outer end, an annular sealing element having a portion telescopically mounted with respect to a cooperating part of the cylinder to permit movement of the sealing element axially of the cylinder, said sealing element projecting radially beyond said cylinder and having a curved end surface in sliding contact with said valve track, the end surface of the sealing element being shaped and distributed so that the center -of gravity of said surface lies ahead of the center of pressure between the relatively sliding surfaces, considered in the direction of relative movement of the element with respect to the valve member, when the sealing element is in its proper operative position of rotation with respect to its own axis, and means engaging the sealing element to prevent its being operatively assembled in any other position of rotation.

2li. In an engine, an annular ported valve member having an inner face providing a spherically curved valve track, a cylinder bank mounted within said valve member for relative rotation with respect thereto, said bank including a cylinder open at its outer end, an annular sealing element having a cylindrical portion telescopically mounted with respect to a cylindrical part of the cylinder to permit movement of the sealing element axially of the cylinder, said sealing element projecting radially beyond the end of the cylinder and having a spherically curved end surface in sliding contact with said valve track, said spherically curved surfaces and said cylindrical surfaces permitting turning movement of the sealing element about its axis, the end surface of the sealing element being shaped and distributed with respect to the axis of the sealing element and with respect to the center of pressure between said end surface and the valve track to tend to cause the sealing element to assume a given position of rotation about its own axis due to friction between the sealing element and the valve track when the engine is in operation, and means engaging said sealing element to prevent rotation thereof about its own axis, said means being constructed to positively locate the sealing element substantially in said given position of rotation and to prevent its being operatively assembled in any other position of rotation.

' 25. In an engine, a ported valve and a ported cylinder mounted to have relative movement with respect to each other, a sealing element movably carried by said cylinder and in sliding contact with the valve, a shoe in sliding contact with the valve, said shoe having an opening therein through which said sealing element passes, and an adjustable connection between said shoe and said cylinder for locating said opening relative to the axis of the cylinder, said shoe providing an abutment for absorbing thrust produced by friction between said element and said Valve.

26. In an engine of the type in which a bank of cylinders and an encircling ported valve are mounted to have relative rotational movement, a peripherally continuous annular shoe in sliding contact with said valve, sealing elements projecting from said cylinders through openings in said shoe into sliding contact with said valve, and an adjustable connection between said shoe and the cylinder bank for locating the shoe peripherally with respect to the cylinder bank and for transmitting thrust produced by friction between the shoe and the valve to said cylinder bank independently of said sealing elements.4

27. In an engine, an annular ported valve and an open ended cylinder mounted to have rotational movement relative to each other, an annular sealing element having a barrel portion telescoping the open end of the cylinder and an end sealing surface in sliding contact with the valve, there being substantial annular clearance space between saidbarrel portion and the cylinder, rings for sealing said space, and means for maintaining said clearance against the thrust developed by friction between the sealing element and the valve comprising a part providing an abutment laterally contacting the portion of the sealing element projecting past the cylinder and a connection for adjustably iixing said part with respect to the axis of the cylinder.

28. In an engine, an annular ported valve and an open ended cylinder mounted to have rotational movement relative to each other, an annular sealing element having a barrel portion telescoping the open end of the cylinder and an end sealing surface in sliding Contact with the valve, there being substantial annular clearance space between said barrel portion and the cylinder, rings for sealing said space, and means for maintaining said clearance against the thrust developed by friction between the sealing element and the valve comprising a shoe in sliding contact with said valve and having an opening through which the portion of the sealing element projecting from the cylinder passes, and a connection for adjustably locating said shoe and the opening therein with respect to the axis of the cylinder, and to thereby provide laterally yabutting thrust absorbing contact between the last mentioned portion of the sealing element and said shoe.

29. In an engine, an annular ported valve and an open ended cylinder mounted to have rotational movement relative to each other, an annular sealing element having a barrel portion telescoping the open end of the cylinder and a circular flange portion providing an end sealing surface in sliding contact with said valve, a shoe in sliding contact with said Valve and having a circular opening in which said flange portion is located, there being greater clearance between the barrel portion of said element and the part telescoped thereby than between said flange portion and said shoe, and means for adjustably locating the shoe and the opening therein with respect to the axis of the cylinder.

30. In an engine, an annular ported valve and an open ended cylinder mounted to have relative rotational movement with respect to each other, and an annular sealing element telescopically mounted at the ported end of the cylinder and having an end sealing face in sliding contact with the valve, the center of gravity of said element being located to one side of a plane passing through the central longitudinal axis of the element and at right angles to the plane of said relative rotational movement.

31. In an engine, an annular' ported valve and an open ended cylinder mounted to have relative rotational movement with respect to each other, and an annular sealing element telescopically mounted at the ported end of the cylinder and having an end sealing face in sliding contact with the valve, the center of gravity of said element being located on the trailing side, considered in the direction of rotation of the cylinder relative to the valve, of a plane passing through the central longitudinal axis of the sealing element and at right angles Ito the plane of said relative rotational movement.

32. In an engine, a ported valve and a cylinder mounted for relative rotational movement with respect to each other, said cylinder having a cylindrical bore at one end providing a port, and an annular sealing element telescopically mounted in said port for movement axially of the cylinder and having an end sealing surface in sliding contact with the valve and said sealing element further having an eccentrically located bore therethrough whereby to cause the element to be eccentrically loaded by fluid pressure within the cylinder.

33. In an engine, a ported valve and a cylinder mounted for relative rotation with respect to each other, said cylinder having a cylindrical bore providing a port at one end of the cylinder and an annular sealing element having a barrel portion telescopically mounted in said bore and a flange portion in sliding contact with said valve and said sealing element further having an eccentrically located bore passing therethrough to provide greater contact surface on one side of a plane passing through the axis of the element than to the other side of said plane and to provide a larger area expo-sed to gas pressure in the cylinder at the opposite end of said element and to one side of said plane than to the other side of said plane.

34. In an engine, a ported valve and an open ended cylinder mounted for relative rotational movement with respect to each other, an annular sealing element carried by the open end of said cylinder and having an end sealing surface in sliding contact with said valve, the center of gravity of the area of said sealing surface being offset in the plane of relative rotation with respect to the axis of said element, and means for limiting rotational movement of said sealing element about its own axis.

35. In an engine, a ported valve and an open ended cylinder mounted for relative rotational movement with respect to each other, an annular sealing element carried by the open end of said cylinder and having an end sealing surface in sliding contact with said valve, said sealing surface being shaped to provide a greater area in contact with said valve on one side of a plane passing through the central longitudinal axis of the sealing element than on the other side of said plane, and means for maintaining the sealing element in a position of rotation with respect to the cylinder so, that said plane is transverse with respect to the plane of said relative rotational movement and the greater contact area is on the trailing side of the transverse plane, considered in the direction of movement of the cylinder relative to the valve member.

36. An annular sealing element for engines comprising an annular barrel portion for telescopic sliding mounting with respect to a cylindrical cylinder part and a spherically curved end sealing surface for sliding contact with a valve of complementary curvature, the center of gravity of said end sealing surface coinciding with the longitudinal axis of said annular barrel portion and the center of gravity of said element being offset with respect to the longitudinal axis of the element.

37. An annular sealing element for engines comprising a barrel portion for telescopic sliding mounting with respect to a cylindrical cylinder part and a flange portion having a spherically curved end sealing surface for sliding contact with a valve of complementary curvature and said element further having a bore therethrough located eccentrically with respect to the longitudinal axis 0f the element.

38. In an engine, a circular ported valve having a concave spherically curved inner face, a bank of cylinders mounted within said valve for relative rotation with respect to the valve, sealing element associated with the cylinders and in sliding engagement with said valve face, and a circumferentially continuous one-pieceshoe in slidingl engagement with said valve, the wall of said shoe being of substantially uniform thickness peripherally around its entire circumference and having a convex spherically curved outer face matching said valve face and a series of circumferentially spaced openings therein for said sealing elements.

39. In an engine, a circular one-piece valve having ports therein and a concave spherically curved inner face, a bank of cylinders mounted within said valve for relative rotation with respect to the valve, sealing elements associated with the cylinders and in sliding engagement with said valve face, a circumferentially continuous circular annular one-piece shoe in sliding engagement with said valve, said shoe having a convex spherically curved outer face matching said valve face and having a cross-section in radial direction substantially uniform peripherally around the entire circumference of the shoe and suiciently thin in radial section to permit elastic distortion of the shoe from its normal circular form to an elliptical form, whereby to permit insertion of the shoe into operative position withiny the valve by elastic distortion of the parts, and a series of circumferentially spaced openings in the shoe for said sealing elements.

ANDR J. MEYER.