US2057123A - Means for lubricating and cooling engine valves - Google Patents

Description

Oct. 13, 1936. w. B. ULLRICH 2,057,123

MEANS FOR LUBRICATING AND COOLING'ENGINE VALVES Filed Nov. 9, 1935 ATTORNEYS Patented Oct. 13, 1936 UNITED STATES PATENT OFFICE MEANS FOR LUBRICATING AND COOLING ENGINE VALLES My invention relates to internal combustion engines employing reciprocative valves of the poppet type for controlling the fuel inlet to the cylinders and the discharges therefrom; and

:;more particularly it relates to improved means for automatically lubricating and cooling the exhaust valves controlling the discharges of the hot burned gases. i

In the operation of the conventional four cycle engine, the exhaust valves receive scanty lubrication even though the endsprojected beyond their guide bearings be provided with a liberal supply of oilor oil mist, due to the pressure of the hot exhaust gases of combustion entering the guide "bearings below the valve head and opposing adequate entry at the opposite end of said bearings of the oil supplied to the reciprocated projecting valve stems. And while portions of the exhaust valve stems and their guide bearings adjacent their valve heads receive some lubricant deposit from the passing exhaust gases in-the form of incompletely consumed fuel constituents and partially burned oil that leaked past the piston rings, due to lack of any means for removing this deposit while mobile, subsequent exposure to the hot exhaust flames builds up this deposit into a gummy, tenacious film, forming eventually a hard tough carbon residue, retarding free action of the valve, and causing it finally to stick in partial or fully opened position, resulting in burning of the valve head and seat, complete valve failures, and costly damage tothe cylinder block and head.

I am aware that attempts have heretofore been made to lubricate and cool the exhaust valves .of internal combustion engines, one such means employing pump or blowers to force oil or oil mist into the guide bearing for the valve stem and through the latter to impinge against the valve head and then to be passed-off through the usual exhaust manifold and muffler. Such means has the inherent disadvantage of requiring additional working parts, and is likely to quickly result in defective valve operation by the formation of the before mentioned tough carbon residue in the exhaust passageways and extending through the entire exhaust line including the manifold and mufiier, requiring frequent costly disassembling and cleaning, besides causing unnecessary and excessive smoke discharge to the atmosphere due to the burning oil.

Other attempts at cooling, employing a jet of air introduced through a hollow stem, or other means, to strike against the valve head, also requires additional working parts, and, as the valve 55'heads of modern engines often operate at red hot heat, and the air jet carries oxygen, such jet tends to intensify the hot flame of the exhaust gases and soon results in rapid oxidation and scaling of the valve head and stem and adjacent parts which quickly causes valve failure.

Recognizing the need of better lubrication and cooling of the exhaust valves of internal combustion engines, it is the object of my present invention to provide novel and improved means for supplying lubricant to the exhaust valve stem and its guide bearing, automatically and without the need of auxiliary equipment or power driven Working parts, by utilizing solely the intake suction developed by the pistons reciprocating in their cylinders. Furthermore my objects are to insure an adequate and desirably controlled supply of lubricant entering said stem guide bearing so as to form an oil film therein between said stem and bearing for free reciprocative movements of l the valve; to act as a-heat conductor between said stem and guide bearing in facilitating cooling the valve; to provide an oil seal preventing exhaust gases passing through the guide causing lubricant contamination; to furnish additional oil deposit on the valve stem and guide bearing adjacent the valve head and remove the same while in a mobile state; and to insure a constant supply of fresh oil as the film within the bearing is weakened or broken down by service and heat.

With the above objects outlined, and with other objects and advantages that will be developed later herein, my invention comprises the improved engine construction and the new method or system of its automatic exhaust valve lubrication and cooling operation more fully described in connection with the accompanying drawing, and the novel features thereof are specifically set forth in the appended claims.

Fig. 1 is a sectional elevation indicating the alined valves for two adjacent cylinders of a conventional four cycle L-head type of internal combustion engine, other engine parts being omitted as of usual known construction and not essential to a full disclosure of my invention, a prepared embodiment of which is disclosed in connection with this valve showing.

Fig. 2 is a fragmentary sectional elevation through the cylinder of another conventional type of engine, showing my invention applied to the overhead valves thereof.

Fig. 3 is a similar sectional elevation of a socalled F-head type of engine, showing my invention applied to its valve construction.

Fig. 4 shows a sectional elevation of a guide bearing for the stem of a usual poppet valve, em-

stems 6, 6 respectively, mounted in guide bear-' ings 1, l, with usual springs 8, 8 and tappets 9. 9' to operate the valves in known timed relation to admit a charge of combustible mixture at each cylinder intake suction stroke to either extension IU, or ID from passage-way 3 fed bya usual inlet manifold in well known manner. Two exhaust valves l5, 15 having stems l6, [6, are shown mounted in a similar manner in guide bearings 11, I1, and have springs I8 and I8 and tappets l9 and 19 to operate them in timed and cooperative relation with inlet valve 5 and 5' to discharge the burned gases from chambers I0 and 10 through passage-ways 4, 4', and: then through a usual exhaust manifold, mufiler and discharge pipe to the outside air.

The valve structure above set forth is conventional and its known operation well understood.

Lubrication of the moving valves is necessary,-

and the drawing shows oil apertures 20 in the cylinder block 2, through which oil is splashed,

as from the crank case, and contacts with the :valves and their stems have proved satisfactory due to the suction of each intake stroke of the cylinders creating suction in inlet passage-way 3, and such suction assists capillary attraction to draw oil upward in the guide bearings. In the case of the exhaust valves however, the discharging burned gases cause a reversely directedpressure in the guide bearings for the exhaust valve stems, opposing the entry of oil theretoby stem reciprocation and capillary attraction, producing inadequate lubrication. Lack of an oil film around such exhaust stems, not only produces friction and quick wear, but fails to seal the bearing and permits burnt gases to pass through the 7 bearing into the valve chamber to quickly contaminate the oil supply therein. A film of oil around the stem is also essential to 'act'as a:

conductive medium to help cool the valve and its stem by carrying the heat to the cylinder'b'look 2,

cooled by a usual water jacket or radiating fins. Furthermore the discharging burned gases contain more or less unburned products and partially burned oil that has passed by the usual piston rings, and such unburned products'and partly burned oil form deposits on the exhaust valve'l5 and I5 and their stems l6 and I6 and enter the upper parts of their guide bearings I"! and H, and without provisions to remove them while still mobile, these deposits quickly cause completevalve failure as hereinbefore 'set forth.

To overcome the above ineffectivelubrication' of the exhaust valve stems, I employ the suction induced by the reciprocated pistons, and employ this suction to aid in drawing a film of oil into the guide bearing for such exhaust valve stem, to remove the exhaust deposits on the valve and the upper end of its stem, and to cause a constant removal of such film when weakened or destroyed by the heat of the exhaust gases so as to maintain through lubrication and proper sealing of the guide bearing, and improved valve action with longer periods between necessary engine overhaulings.

In employing this intake suction of the engine for the above stated purpose, I have shown in Fig. 1 a simple efiective means consisting of suction passage- ways 25 and 25 connecting the inlet passage-way 3 to the respective bearings for valve stems l6 and I6, such passage-ways being readily provided as by the drilled holes shown in the cylinder block 2 extend-ed through the guide bearings to the respective stems.

These suction passage- ways 25 and 25 permit the suction at each intake stroke of the cylinders, to cause a. partial vacuum in the guide bearings l1 and H, to preferably at a point intermediate their length as shown, such partial vacuum tending to assist the flow of lubricant upward into the bearing from its lower end, and to draw down into the bearing at its upper end the exhaust deposits on stems I6 and I6 while still mobile, and to cause such oil and deposits to pass through passage-ways 25 and 25' to be mingled with the intake charges of combustible gases passing to chamber 10 and I0 depending on which inlet take 5 or 5 is in open position.

The suction action of the intake through said passage-ways 25, 25' automatically acts to draw in a film of oil into the guide bearings I1 and I1, and aided by capillary attraction to hold the same therein until broken down by heat, when it is drawn 01f into the intake system and mixed with the incoming fuel for combustion with the latter, new oil automatically entering the guide bearings as such exhausted oil is drawn off. A dry valve stem is very inefficient in transferring its heat to the guide bearing and cylinder block for cooling, and by maintaining a conductive film of oil surrounding said stems as above described, cooling of the stem and valves is greatly improved, and at the same time a more accurate machine fit of the stem in its bearing may be employed giving better and more lasting operation. Sticking valves are also prevented as the exhaust deposits on the stems and upper parts of the guide stems are removed while still mobile and passed back into the inlet charges before being burned into a hard residue by subsequent exhaust discharges. Also the film maintained in the guide bearing seals the same to prevent back pressure and oil contamination by leakage of the'exhaust fumes through the guide bearings into the valve chamber. such improved lubrication of the exhaust valves the efficiency of the engine is greatly improved, necessity for reconditioning materially lessened, and oil consumption reduced due to lack of contamination from exhaust fumes.

The guide bearings l1 and I1 mentioned above may be formed directly in the cylinder block 2, but are more commonly made, as shown, as separate parts secured to suitable apertures in the block 2. In Fig. 4, I have indicated a guide bearing 30 particularly adapted for my present purposes, and form the same with an annular external groove 3| communicating by means And due to at aheight to register with the suction passage-' way formed in the cylinder block 2, so that when the guide bearing is employed as a repair replacement, said groove may register with the passage-way, indicated by dottedlines 35, without required necessity of positioning the same. The oil groove 33 is notessential but is useful where extreme conditions are encountered to assist the entry of oil into the bearing, and such groove is preferably extended above the aperture 32 but'short of the upper end of the bore, such upper end facilitating removal of the exhaust deposit on the upper end of the valve stem. The

depth of the groove may be used to control or meter the admission of oil to the bearing.

In Fig. 2 I have indicated an overhead type of valved engine, showing the cylinder 40, and the valves 4| and. 42 in'the head 43, directly over the cylinder. 3 Guide bearing 44 for the stem 45 of exhaust valve 42 is shown with aperture 46 communicating with passage-way 41 to admit intake suction to its inner bearing surface so as to lubricate stem 45 in the manner above set forth and with the aforesaid improvements and advantages.

Fig. 3 indicates a so-called F-head type of valve arrangement, the exhaust valve 50 in this case having its stem 5| guided in bearing 52, and intake suction is provided for by means of a passage-way 53 cored in the engine block with an end connection, not shown, to some point in the inlet passage-way or manifold, and individual branch passage-ways 54 from said passage-way 53 to the respective exhaust guide bearings 52. And it will be understood that other means than above disclosed, may be employed to connect the guide bearing for the exhaust stems with the intake suction for the purpose above set forth. Also it will be understood that the guide bearings for the valve stems may be formed directly in the cylinder block, Fig. 1 indicating guide bearing H as part of the block 2. And the passage-ways from inlet passageway to stem bearings may be in the form of a tube or conduit 55 passing through the usual water jacket, as shown in Fig. 3. The application of my improvements is not limited to four cycle engines but may conceivably be applied to other engines having an intake exerting a suction.

From the foregoing description it is believed the nature of my invention, its simple application to conventional engine construction, and its contribution to improved engine operation, will be readily understood. Also that the particular embodiment disclosed may be modified and changed without departure from my invention as defined in the following claims.

What I claim is:

1. In an internal combustion engine having cylinder inlet and exhaust passage-ways and provided with poppet-valves and a lubricant supply chamber therefor, an exhaust-valve stem bearing having a bore-end thereof extended into said supply chamber and provided with a suction conduit extending from above said bore end to the inlet passage-way, whereby suction produced by opening of the inlet valve acts to draw lubricant through said bore-end into said exhaust valve bearing.

2. In an internal combustion engine having cylinder inlet and exhaust passage-ways and provided with poppet-valves and a lubricant supply chamber therefor, an exhaust-valve stem bearing havingone end of the. bore thereof arranged in communication with said supply chamber and the other end thereof in communication with the exhaust passage-way, an intermediate portion of said bore being provided with a suction conduit extending to theinlet'pass'age-way, whereby suction'produced by-opening of the inlet valve acts to draw therethrough lubricant from one bore end and exhauststem-deposited products from the other bore end.

3. In an internal combustion engine having.

cylinder inlet and exhaust passage-ways and pro' vided with poppet-valves and a lubricant supply chamber therefor, an exhaust-valve stem bearing 4: In' an internal combustion engine having cylinder inlet and exhaust passage-ways and provided with poppet-valves and a lubricant supply chamber therefor, an exhaust-valve stem bearing having one end of the bore thereof arranged in communication with said supply chamber and the other end thereof in communication with the exhaust passage-way, a spiral groove in said bore extended to said lubricant communicating end and an intermediate portion being provided with a suction conduit extending to said inlet passageway, whereby suction produced by opening of the inlet valve acts to draw therethrough lubricants from one bore end and exhaust stem-deposited products from the other end.

5. An internal combustion engine comprising separate inlet and exhaust passage-ways, separate inlet and exhaust poppet-valves for the respective passage-ways, a housing for said valves having a lubricant supply chamber, guide bearings for said valves having bearing bores for their respective valve stems extended into said lubricant supply chamber, and a suction conduit connecting the exhaust valve stem bearing bore with the inlet passage-way adjacent the inlet valve, whereby suction produced by the opening of said inlet valve acts to draw lubricant from said supply chamber into said exhaust stem bearing bore.

6. In a multi-cylinder internal combustion engine having inlet and exhaust passage-ways provided with separate poppet valves controlling communication with the respective cylinders and lubricant supply chambers for the several valves, guide bearings for the exhaust valves each having its bearing bore in communication at one end with a lubricating chamber and at its other end with the exhaust passage-way, and an intermediate portion of each bore being provided with a suction conduit extending to said inlet passageway whereby suction produced by opening of the inlet valves acts to draw therethrough lubricant from one end of each bore and exhaust stemdeposited products from the other end of each bore.

'7. Ina multi-cylinder internal combustion engine having inlet and exhaust passage-ways provided with separate poppet valves controlling communication with the respective cylinders and lubricant supply chambers for the several valves, guide bearings for each exhaust-valve stem having a bearing bore extended into its lubricant supply chamber, and a common suction conduit extending from said inlet passage-way with sepa- 75 rate branches 1 therefrom to each exhaust valve stemxbearing, whereby suction produced: by opening of the inlet valves actsto draw lubricant into saidexhaust valve bearing bores.

.8. In :an internal combustion engine having cylinder inlet and exhaust passage-ways and provided with poppet valves .and a lubricant supply chamber therefor, anexhaust valve bearing: com-,

passage-way, whereby suction produced by .open-' ing of the inlet valve acts to draw lubricant into said guide bearing bore.

;9.-A renewable bearing for the-exhaust valve stems of internal combustion engines having inlet and exhaust passageways provided with. poppet valves and .a lubricant suction conduit extendingfrom'said inlet passage-way to said exhaust valve bearing, comprising a removable guide member having an exterior encircling groove adapted to register withsaidlubricant suction conduit, an interior bearing borehaving a lubricant admission end, .and anaperture connecting said bearing bore and'said exterior guide encirclinggroove.

10. A renewable bearing for the exhaust valve stems of internal-combustion engines having inlet and exhaust passage-ways provided with poppet valves and a lubricant suctionv conduit extending from said inlet passage-way torsaid exhaust valve bearing,- comprising a removable guide member having anexterior encircling groove adapted to register with said lubricant suction conduit, an interior bearing-bore having a spiralbil groove therein extending inwardfrom a lubricant admission bore-end, and an' aperture connecting an intermediateportion' of said spiral groove with said extension guide encircling groove.

' B. ULLRICH.

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