US1784555A - Means to prevent valves from sticking - Google Patents

Description

Dec. 9, 1930. c. E. SUMMERS MEANS TO PREVENT VALVES FROM STICKING Filed March 31. 1928 IIIIIIIIIIIII/IIIIII 15 J 1 m 5.5;; 6 5m .0 o whi Patented Dec. 9, 1930 o rrEDs ATEs PATENT OFFICE CALEB n snMMERs, orronrmc, tncmean, elssrenon T GENERAL MOTQRS con- POR-ATION, or nn'rnoirgivrrcnrean, A conronerron or DELAWARE MEA S ro PREVENT VALVES FROM STIGKING Application filed March 31,

' This'invention relates to an internal combustion engineiand more particularly to an exhaust valve.- 7 a "One of the defects of poppet valves is the tendency, under certain conditions, of the exhaust valve stems to stick in their guides to such an extent that the valve spring pres- "sure is insuflicient to close thevalves.

Observation indicatesthat' in a majority "It isfan object of the present invention to prevent the sticking of the valve stems by preventing the oilfrOm W rking up along the valve stems to alpoint where the temperature is suiiiciently high to causedecomposigradually cooler 'tolowing description, taken in connection with the accompanying drawing and appended claims.

In the drawing:

Figure 1 is aitransverse vertical section with parts broken away, taken through a portion of an internal combustion engine embodying my invention.

valve stem guide shown in Figure 1.

Figure 3 is a section on the line 3-3 of Figure 2. a Figure 4 is a view similar to Figure 1 but showing a modified form of my invention.

Figure 5 is a view similar to Figure 1 and showing another modification of my invention.

Referring to the drawing, I have illustrated in Figure 1 a portion of an internal combustion engine including an engine block 1928. Serial No. 266,282.

6 and cylinder head 8. The engine block,

sleeve 22. of cases, valve sticking is due to oil which i :workswup between the valve. stem and its guide and at somepoint between the topand bottom of the guide, is subjected to a temperature high enough to decompose or car bonize the oil. Thepaccum'ulationiand hardening-of the material thus produced causes the valve to stick. p a

Slidablevin the bearing sleeve 22 is a valve stem 24 provided on its upper end with a valve head 26 adapted to seat on the valve seat 16., The lower end of the stem carries-a washer, 40, and surrounding the stem between the washer 4:0 and the web 20 isthe usual valve spring 12 for holding 'the'valve seated. VThe valve stemmay be lifted in any usual 'or suitablemanner, as by a cam shaft 11 and "tappet 30.; l i

Just-underneath the Web '20-,the bearing.

sleeve 22 is provided with a lateral recessior chamber 456; 1' This recess may be produced by drilling a'hole through the, wall of the sleeve,

as shownjin Figure 3, the boreof the recess being slightly larger than theinternal diameter of thebearin'gsleeve sothat a circular pocket I or open space is left about, the inner surface of the'bearing sleeve, opening out through the sideof the sleeve. l V V v This clearance interrupts orbreaks thecontinuity of the sliding or bearing surface en tirely around theperiphery ofthevalve stem and affords an annular pocket or" recess into.

which any oil carried upward on the valve stem durlng valve movement'entfers and is col- 'lected for return to-the' tappet. chamber.

Since the clearance space completely sur- Fig re 2 isan enlarged side view of the rounds thelvalve Stemt'he hke'hhood of 011 being pumped to a point of high heating is ing oil gathers upon the lower end of the stem and works upward to the region of opening 46. Since thepressurexwithin the exhaust portl4 is constantly changing and is frequently above atmospheric pressure while the engine is running, there may at times be a vent the rise of oil past the opening 46 and will also cause any excess oil to pass out through this opening. The upper portion of the sleeve 22 may be lubricatedif desired with any heat resistant lubricant,.such as, graphite.

In Figure 4: I have illustrated a slightly.

modified form of my invention in'which a bearing sleeve 23 supported the web is provided on its inner surface with an annular groove 50, and with a port 52 through the bearing sleeve in the lower part of the groove.

Itwill be apparent that during the lifting movement of the valve =o'fl its seat there will her, a valve stem guide bushing projecting thru a wall of said" chamber, and "having; a

be a tendency for the lubricating oil film carried by the va lve'stem to work up on the contacting surface' o'f the guide until the contact is broken by the annular groove where the oil is-collecte'd and returned to the tappet chamber. A part of this oil may sti ll cling to that part of the stem moved into the groove and beyond the lower guide surface, and to prevent its being deposited on the upper guide surface beyond the groove it is desirable that the siZe of groove50, takenaxial l-y of the valve stem, be slightlygreater than the valvelift so thatthatpartof the stem which contacts with the lower guide surface when the valve is seated may move into the groove when the valve is unsea-ted, but will at no time move far enough to contact with the upper guide surface and thus the oil thereon will not be carried past the groove 50.

In the modificationshown igu're 5, :a

bearing sleeve '60 isfixed' in web:f20 and is.

formed with a bearingsurface which is :reduced at its lower end. J ournaled invthe bearing is avalve-stem comprising an upper portion 62 anda reduced lower end 54. An

opening is formed in theside-ofthe bearing sleeve at the top of the reduced portion of the bearing, it being notedthat'thereduced V end 54 of the valve stem extends some dis- J tance above the opening 55, this arrangement providing an annular chamber between the valve stem and-bearing. The embodiment V illustrated in this view is otherwise the same as thatdescribed above.

Iclaimzon the bearing surfaces 'of' valve parts o f'an internal combustion engine or the 'like,-in-.

cluding incombination, a valve tappet chamtransver'se opening of adiameter greater than that of the bore of the bushing drilled thru the side thereof and located below said wall to provide a space in direct communicationwith said tappet chamber, and a valve stem slidable in said bushing.

'2. Means to prevent 'gummin'g of lubricant diameter than the bore, to provide an interior annular recess in direct communication with the tappet chamber, and a reciprocatory valve stem mounted in said bushing.

-3. Means to-preventgumming of lubricant on the bearing surfaces of valve parts of an internal combustion engine or the like, including in combination a valve tappet chamber, a valve stem guide bushing projecting into said chamber thru a wall thereof, and having an interior recessed portion, the'wall of said bushing having 'anopening therethru in that portion thereof =thatextends -into said chamber, to place the recessed portion in -.di rect communication with the valve .itappet chamber, and a valve stem reciprocably mounted insaid bushing. r i I 1 4. The structure 'offclaim 3'wherein the length of the recessedp'ortion is greater' than the range of reciprocation of the valve.- stem.

5. Means to prevent gummingo'f lubricant on the bearing surfaces of valve .partsof-an said -c'hamberthru a wall thereof, anda valve stemmember slidably mounted inlsaidguide .DIGHIbBI', the adjacent surfaces of said members=beingspaced apart for a portion oftheir extentzto Lprovide clearance therebetween, and

the wall of said guide member .having alat- ,eral opening in that portion projecting into the tappetichamber, leading to said clearance space, whereby said clearance space is .in

direct communication with said chamber. V

In :testimony whereof I affix my signature.

. CALEB E. ESUMMERS,

tappet

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