US2387143A - Engine - Google Patents

Description

et. 16, 1945. w. G. GERNANDT ETAL 2,387,143-

v ENGINE Filed Feb. l5, 1945 2 Shets-Sheet l 47 I N VEN T0125,

A TTOKNE YS.

W. G. GERNANDT ET AL ENGINE @ci 16, i945.

' 2 Sheets-Sheet 2 Filed Feb. 15, i943 [J0 6.' 6'@ BY HZfreJ W'Z/fs/z ATTORNEYS.

w T m V m Patented Oct. 16, 1945 ENGiNE Waldo G. Gernandt and Alfred E. Walden, De-

troit, Mich., assignors toBrggs Manufacturing Company, Detroit, Mich., a corporation of Michigan Application February 13, 1943, Serial No. 475,757

(Cl. 12S-80) 25 Claims.

This invention relates to internal combustion engines and particularly to the valve mechanism thereof. Engines of the class to which the present invention relates are provided with rotatable valves, preferably although not necessarily rotating continuously in one direction, for controlling the intake and firing of the combustible mixture or fuel charge and for exhausting the products of combustion.

In the present preferred embodiment of this invention the rotatable valve is mounted in the cylinder head and is formed with substantially all or at least the majorportion of the combustion chamber. Moreover, in the illustrated embodiment the valve or rotor is substantially truste-conicalin construction having an opening or port in the side of the valve adapted to communicate with an intake or exhaust passage, or both as the case may be, and also an opening or port at the inner end or bottom of the valve leading to the cylinder. With the exception of these ports the combustion chambe;` is otherwise entirely enclosed or housed within the walls of the valve member or rotor. The combustible charge within the combustion chamber of the valve is fired preferably by spark ignition although in its broader aspects the invention is not considered to be so limited.

Serious problems have been encountered heretofore in the production of a satisfactory engine of the foregoing kind, particularly because of the inability to obtain sufficient power output or maintain eiflclent and sustained high speed per formance, such as required for engines used in aircraft. Some of the principal problems orA difculties have been in connection with the lubrication of the rotary valve, satisfactory control and reduction of oil consumption, elimination of gas leakage and consequent power loss during the power and compression strokes of the piston. and

the provision of adequate properly lubricated bearings oi simplified nature for the valve in order to prevent reduction in power output due to excessive friction, lscoring and wear of the valve.

An object of the present invention is to overcome some or all of the foregoing difculties by providing an improved internal combustion engine of the rotatable valve type which will have improved power characteristics, will be capable of meeting exacting requirements in respect to sustained operation, and will have longer life while maintaining a more nearly constant performance rating during such long usage.

A further object of the invention is to provide an engine of the foregoing class having improvedk bearing means for the valve and improved means for sealing the exhaust opening particularly at the time of firing the charge in the valve combustion chamber.

Another object of the invention is to eliminate.

elaborate or relatively complicated bearing arrangements for the valve and to provide, instead,

a simple and efficient bearing means for the valve which will overcome difficulties heretofore encountered due to severe wedging action or thrust of the valve against its seat, tending to impair seriously the oil film between the surfaces of the valve and its bearing seat in the cylinder head and frequently resulting in seizing and scoring of the valve. 1

A still further object of the invention is to provide an improved internal `combustion engine of the generally truste-conical valve type in which the valve is relieved in such improved manner as to reduce materially the area thereof subject to high bearing loads during operation.

Another object of the invention is to provide an engine having a generally frusto-conical valve formed with a combustion chamber and having its outer tapering wall relieved centrally around the valve so as to provide, spaced bearing areas or bands at the smaller and larger ends thereof designed to receive the principal bearing loads during operation. A further object of the invention is to improve the operation and performance characteristics of the engine by circumferentially relieving the outer wall of the valve eccentrically with respect to the axis of the valve and preferably in such manner as to reduce friction at critical times rand provide more effective sealing o f the gases against leakage around the exhaust opening during the firing of the mixture.

Another object is to provide an engine having improved means adjacent the outer end of the cylinder for mountingr or retaining the valve within the valve cavity in the head.

Other objects of this invention will appear in the following description and appended claims, reference being 'had to the accompanying drawings fcrming a part of this specification wherein like reference characters designate corresponding parts in the several views.

Fig. l is a fragmentary sectional elevation i1- lustrating a portion of a multi-cylinder engine embodying the present invention.

Fig. 2 is an enlarged fragmentary sectional elevation illustrating particularly the associated cylinder head and rotary valve structure together with a portion of the valve driving means shown in Fig. 1.

Fig. 3 is an enlarged section taken substantially through lines 3-3'of Fig. 2 looking in the direction of the arrows.

Fig. 4 is an enlarged sectional detail of the structure enclosed withinY the circle of Fig. 2.

Before explaining in detail the present invention it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustratspark-ignition type designed particularly for the power plant of an aircraft. The invention may obviously be utilized in` connection with engines for other purposes, such as automotive, marine and industrial engines.` For most uses the engine-isotthe multicylinder type. However, for

the purposes of simplicity a single cylinder unit ,of Athe engile lis illustrated in the present embodiment, it being understood that the remaining cylinders of the engine are identical to the structure-herein shown and described.

Referring to Fig. 1, the present engine comprises a suitable crankcase within which is mounted a crankshaft 2| supported in'bearings according to conventional practice. A cylinder 22 is secured rigidly to the crankcase and has its Alower or inner end projecting thereinto. Mounted to reciprocate. within the cylinder is a piston 23 adapted to .be connected in the usual manner by a connecting rod 24 to the crankshaft 2 I.

the present engine the combustion chamber of thercylinder is formed principally within a rotor or rotary valve member 25, this member comprising a frusto-conical body arranged immediately above the piston when at the top of its f. stroke. The valve 25 is provided at its outer end with a cylindrical stern 26.

The rotor 25 flits withinA a substantially correspondingly shaped frusta-conical cavity 2l in an upper cylinder head member 28.

l 'Ihe rotor 25 is driven through the medium of fthe stem 26V which is positively connected to a driving gear in such manner as to permit slight relative axial and radial movement between the driving gear and the `rotor. Accordingly, the stem 26 has a longitudinal splined connection 29 with a sleeve 30 which in turn has a longitudinal splined or toothed connection 3| at its upper end with a driving gear` 32, the gear having a depending cylindrical hub or sleeve 33 interposed between the sleeve 30 and a bearing or bushing 34. The gear 32 has an annular recess 35 at its outer side adapted to receive and house a compression spring 36. This spring is engaged by a retainer 31 which is clamped to the valve stem 26 by means of a nut 38 provided with a shank 39 threaded into a tapped hole in the stem 26. The valve member 25 is formed with a cooling chamber 4|v extending entirely around the combustion cham- :ber of the valve member. This cooling chamber is adapted to receive any suitable cooling medium, such for example as metallic sodium, which is sealed into the chamber by means of a screw plug 40 threaded into the tapped hole in the valve stem 26.

From the foregoing it will be seen that the valve 25 may be rotated from the gear 32 through the medium of the splined connections 29 and 3| which permit slight relative axial and 'radial movement of the valve during operation. The valve is yieldingly vheld ,outwardly against the tapered wall 21 of the valve cavity or recess in 1 the head by means of the spring 36.v 'The driving gear 32 is provided with gear teeth 32a meshing with the teeth of a gear 42 driven by a gear 43 secured to the upper end of artower shaft 44 extending through a tubular housing 45. Secured tothe lower end of the tower shaft is a gear 46, meshing with a gear 41, pinned to the crankshaft 2|.

The rotor 25 is formed with a combustion chamber 48 which preferably forms substantially all of the combustion space at the time of ring when the piston 23 is in its position of maximum compression. The piston is preferably formed with a tapered end 23a which is adapted to project a slight distance into the combustion chamber 43, as shown in Fig. l, and the bottom of the valve is tapered so as to correspond substantially to the shape of the upper crowned or tapered portion 23a of the piston.

In the particular embodiment herein illustrated it will be seen that the rotor or valve 25 has a single port 49 inits side communicating with the combustion chamber 48 and adapted to register in succession with an exhaust conduit 50, an'intake conduit 52 and a spark plug at location 5|. In this embodiment, therefore, the valve or rotor 25 is driven at one-half engine or crankshaft speed, the direction of rotation of the valve being indicated by the arrow in Fig. 3. The driving mechanism, above described and shown inthe drawings; is illustrative of a suitable mechanism by which one of a plurality of rotary valves 25 of a corresponding plurality of cylinders 22 may be driven from the crankshaft 2|. The spark plug llocation 2| is in the form of a tapped hole for reception of a spark plug of any suitable type.

The present engine preferably utilizes a fuel injection system, although it will be understood that the invention is not so limited and that a carburetor may. be employed for supplying the fuel charge to the combustion chamber 48 when the side port 49 vof the valve registers with the intake conduit or passage 52. Where a fuel injection system is used, fuel' may be injected through the medium of any suitable fuel injector (not shown) into the air stream in the passage or conduit 52 so that the rotor will be supplied with the proper combustible mixture at the time of ignition, namely when port 4 9 of the rotor registers with the spark plug at location 5|. It will be understood that suitable lubricating means is provided for the rotor 25 and also for the operating parts of the engine, so as to maintain an oil lm on all surfaces requiring lubrication. The lubricating means for the rotor 25, for example, may be'similar to that shown in copending applications of the present assignee, such as application Serial No. 441,47 4.

In addition to the side port' 49 the valve orrotor 25 is provided at the bottom or inner end thereof with a centrally located port 53 adapted to communicate with the outer end of the cylinder 22. As previously stated, the bottom surface of the rotor surrounding the port 53 is tapered and during operation the valve is normally held outwardly within the tapered or frusta-conical cavity 2l of the cylinder head by the compression spring 36. The cylinder head 28 is formed with a depending internally threaded skirt 28a into which the upper threaded end of the cylinder 22 is adapted to be screwed for attaching the head and cylinder together. Immediately above the upper edge of the cylinder 22 and within an annular recess in the head 28 is located an abutment ring 54 formed of suitable metal or metallic alloy such as bronze. As illustrated particularly in Figs. 2 and 4, the ring 54 is engaged'at its upper face by an annular shoulder 51 forming the upper wall of the recess within which the ring is located, and

when the cylinder is screwed into the cylinder head, the ring 54 is clamped tightly against the upper edge of the cylinder by the shoulder 51, a gasket 55 being interposed between the ring 54 and the upper or outer edge of the cylinder. The inner upper edge of the ring 54 is bevelled as indicated at 56 and the lower edge of the valve member 25 is provided with a corresponding inwardly directed taper 58 facing the tapered or bevelled edge 56 of the ring. The tapered portion B of the valve terminates in an annular portion 59 of reduced diameter lying within and facing the bearing ring 54, there being a suitable clearance 60 between the valve portion 59 0f reduced diameter and the ring 54 and a clearance between the bevelled edges 56 and 58 so as normally to avoid frictional engagement between these parts during operation.

In the present embodiment of the invention the principal bearing loads between the rotor or valve 25 and the head 28 are taken substantially entirely at two localities entirely above and below the side port 49. In the present instance the valve 25 is provided with an annular rel.ef area 46| extending around the central or intermediate portion of the valve and having a height preferably corresponding to the height o-f the side port 49, as clearly shown in Fig. 2. This relief area 6| may be formed by cam grinding so as to provide a circumferentially tapering relief of l diminishing depth around'the valve. This relief area 6| is at The maximum depth of the relief area 6| is pre-v determined. Assuming that itis desired that this maximum clearance be approximately two to live thousandths of an inch over and above the normal running clearance, a point 66 on the line 64 is determined which is two to ve thousandths of an inch from the center or axis, 65. The center of curvature 66 Cf the relief *area is thus spaced on the line 64 from the center of curvature 65 of the valve, as shown at 61. The radius of the relief, having its center of curvature at 66, is shown by the line 68 in Fig. 3. The radius of the bearing cavity 21 in the head is shown by theline 69 with the center of curvature at point 65. The relief area thus formed diminishes in depth in opposite directions and terminates at one end a considerable distance from the leading edge 62 of the valve port, while at its opposite end it terminates relatively close to the trailing edge 63 of the port. Between the edge 62 and the adjacent end of the relief there is thus provided a circumferentially unrelieved area extending ay distance approximating the distance from the spark plug opening 5| to the trailing edge 63 of the valve port.

By providing the relief band 6| centrally of the valve 25 it will be seen that the principal bearing loads during operation, and particularly at the time of explosion, will be taken in the annular tapering areas 10 and 1| of the valve which have a normal operating clearance with respect to the bearing cavity 21 in the head.

From the foregoing, referring particularly to Fig. 3, it will be seen that the relief area 6| is formed eccentrically `with respect to the valve axis and its maximum depth is nearer the trailing edge 63 of the port 49 than it is to the leading edge 62 thereof. Hence, at the time of ring when the port 49 registers with the spark plug at location 5| displacement of the cone or valve 25 will occur in an upward and lateral or radial direction toward the side of the head opposite to the spark plug at 5|. of relief as well as the unrelieved area is proximate to the leading edge 62 of the valve port at the time of firingy this minimum relief portion will Y be at the locality of the exhaust conduit 50. Hence, at the time of ring and during the power stroke an effective seal of the valve at the exhaust conduit 56 will occur thereby minimizing loss of gases through the exhaust conduit and hence preventing any material loss of power.

We claim:

1. In an internal combustion engine, a cylinder head, and a rotatable generally frustoconical valve therein, said valve having a circumferential relieved area of reduced diameter terminating short of one end of the valve and extending only partially around the valve.

2. In an internal combustion engine, a cylinder head, and a rotatable generally frustoconical valve therein, said valve having a circumferential relieved area of reduced diameter terminating short of the larger end of the valve and extending only partially around the valve.

3. In an internal combustion engine, a cyl` inder head, and a rotatable generally frustoconical valve therein, said valve having a, circumferential relieved area of reduced diameter terminating short of the smaller tapering end of the valve, and extending only partially around the valve.

4. In an internal combustion engine, a cylinder head, and a rotatable generally frustoconicalvalve therein, the outer tapering wall of said lvalve and the juxtaposed wall of the cylinder head being relatively reduced to provide a circumferential relieved areaextending only partially around the valve, said area having greater clearance between said juxtaposed walls than the of the valve and cylinder head Walls.

5. In an internal combustion engine, a cylinder head, and a rotatable generally frusto-conical valve therein, said valve having the outer tapering wall thereof reduced to provide a circumferential relieved area having greater clearance with respect to the juxtaposed wall of the cylinder head than adjacent portions of said valve wall at opposed sides of the relieved area, said relieved area extending only partially around the valve.

6. In an internal combustion engine, a cylinder head,v and' a rotatable generally frusto-conical valve therein, the outer wall of said valve and the juxtaposed wall of the cylinder head being relatively relieved to provide a circumferential area of varying clearance between the juxtaposed walls of the cylinder head and valve.

'1. In an internal combustion engine, a cylinder head, and a rotatable generally frusto-conical valve therein, said valve having a circumferential relieved area of reduced diameter and varying depth terminating short of one end of the valve.

8. In an internal combustion engine having a cylinder and cylinder head, a rotatable tapering Wall valve therein, said valve having tapering outer wall portions at opposite ends of the valve adapted to have bearing engagement with corresponding walls of the cylinder head, a circurn- However, since the minimum depth ferential area of the valve outer wall intermediate said portions havlngegreater clearance with respect to the juxtaposed wall of the cylinder head, said area of greater clearance extending only partially around the valve.

9. In an internal combustion engine having a cylinder and cylinder head, a rotatable tapering wall valve therein, said valve having tapering outer wall portions at opposite ends oi the valve adapted to have bearing engagementy with co'rf responding Walls of the cylinder head, a circumferential area of the valve outer wall intermediate said portions being relieved only partially around the valve to provide greater clearance with respect to the juxtaposed wallof the cylinder head.

10. In an internal combustion engine having a cylinder and cylinder head,'a rotatable tapering wall valve therein, said valve having tapering outer wall portions at opposite ends of the valve adapted to have bearingengagement with corresponding walls of the cylinder head, a circumferential area of the valve outer wall intermediate said portions having greater clearance with respect to the juxtaposed wall of the cylinder head, said clearance being of varying depth.

11. In an internal combustion engine having a cylinder and cylinder head, a rotatable tapering wall valve therein, said valve having tapering outer wall portions at oppositeends of the valve adapted to have bearing engagement with correspending walls of the cylinder head, a circumferential area of the valve outer wall intermediate said portions being relieved eccentrically with respect to the axis of the valve.

12. In an internal combustion engine, a rotatable generally frusto-conical valve having a combination chamber and a port in the side of the valve communicating with said chamber, said valve having a circumferential relieved area of a height substantially corresponding to the height of said port in the direction of the valve axis.

.13. In an internal combustion engine, a rotatable generally frusto-conical valve having a combustion chamber and a` port in ther side of the valve communicating .with said chamber, said valve having a circumferential relieved area substantially coextensive with the height of said port in the direction of thevalve axis, said relieved area lying substantially between opposite edges of the'port. l

14. In an internal combustion engine, a rotatable generally frustoconical valve having a combustion chamber and a port in the side of the valve communicating with said chamber, said valve having 9, circumferential relieved area of varying depth substantially coextensive with said port in the direction of the valve axis,

,s 15. In an internal combustion engine, a rotatablegenerallyfrusto-conical valve having a combustion chamber and a portin the side of the valve communicating ,with said chamber.l said valve having a circumferential relieved area eccentric with ,respect to the valve axis and extending in the height of said port.

16. In an internal combustion engine, a rotatable generally frusto-conical valve having a combustion chambervand a port in the side of the valve communicating with said chamber, said valve having a circumferential relieved area op bustion chamber and a port in the side' of the valve communicating with said chamber, said valve having a circumferential relieved area of varying depth opposite said port.

18. In an internal combustion engine, a. rotatable generally frusto-conical valve having a combustion chamber and a port in the side of the valve communicating with said chamber, said valve having a circumferential relieved area of varying depth opposite said port with 'its point of greatest depth offset with respect to the transverse center line of the port.

19. In an internal combustion engine, a cylinder head, a cylinder secured at its outer end posite said port with its point of greatest depthlu offset with respect to the transverse center line of the port.

17. .In an internal combustion engine, a rotat- V`Aable generally frusto-conical valve having a comto the head, a generally frusto-conical valve in said head provided with a combustion chamber and a port in its inner end communicating with the cylinder, a ring secured in said head and projecting inwardly of the outer end of the cylinder wall, the adjacent lperipheral edge of thevalve being cut away to receive the inwardly projecting portion of the ring and to overlie the same.

20. In an internal combustion engine, a cylinder head, a cylinder secured at its outer end to the head, a generally frusto-conical valve in said head provided with a combustion chamber and a port in its inner end communicating with the cylinder, e, ring secured in said head and projecting inwardly of the outer end of the cylinder wall, the adjacent peripheral edge of the valve being cut away to receive the-inwardly projecting portion of the ring and to overlie the same, the inner portion of the valve extending within said ring and spaced therefrom.

21. In an internal combustion engine, a rotatable valve having a combustion chamber and a side port communicating therewith, the outer wall of the valve opposite said port having a rel r of the valve opposite said port having a relieved area eccentric with respect to the valve axis and terminating neargr to the trailing edge of the port than to the leading edge thereof.

`23. In an internal combustion engine, a rotatable valve having a combustion chamber and a side port communicating therewith, the outer wall of the valve opposite, said port having `a relieved area eccentric with respect to the valve axis and terminating short of the side edges of the port.

24. In an internal combustion engine, a rotatable valve having la combustion chamber and a side port communicating therewith, the outer wall of the valve opposite said port having a relieved area eccentric with respect to the valve axis and having its point of greatest relief more remote from the leading edge of the port than from the trailing edge thereof.

25. In an internal combustion engine, a cylin-Y der head, and a, rotatable generally frusto-conical valve therein, the outer wall of said valve and the juxtaposed wall of the cylinder head being relatively relieved to provide a circumferential area of increased clearance between the juxtaposed walls of the cylinder head and valve extendingpnl-y partially around the circumference of the valve and of less height than said walls.

` `WALDO G. GERNANDT.

ALFRED E. WALDEN.

CERTIFICATE CF CORRECTION. Patent Ns. 2,587,115. 'octebsr 16, 191,5;

WALDO G. GERNANDT, ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring Correction as follows: Page L1., first column, line 57, claim 12, for "combination" read -combustion; andithat the said Letters Patent should be read with this Correction therein that the same may conform to the record of the ycase in the Patent Office.

Signed and sealed this 9th lay of January, A.MD. 19,46.

Leslie Frazer (seal) First Assistant commissioner o f Patents.

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