US2669981A

US2669981A - Valve rocker mounting

Info

Publication number: US2669981A
Application number: US183026A
Authority: US
Inventors: Clayton B Leach
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1950-09-02
Filing date: 1950-09-02
Publication date: 1954-02-23
Anticipated expiration: 1971-02-23

Description

` Feb. 23, 1954 B, EACH 2,669,981

VALVE:l ROCKER MOUNTING Filed sept. 2, 1950 2 sheets-sheet 1 if I Feb. 23, 1954 c. B. LEACH VALVE ROCKEZR MOUNTING 2 Sheets-Sheet 2 Filed Sept. 2, 1950 :Snventor am/ Gttornegs Patented Feb. 23, 1954 UNITED STATES TENT OFFICE VALVE ROCKER MOUNTING Clayton B. Leach, Pontiac, Mich., assignor to General Motors Corporation, Detroit, Mich., a

corporation of Delaware 12 Claims.

This invention relates to valve operating mechanisms for internal combustion engines and the like, and particularly to the mounting and lubrication of rockers of overhead type valve operating mechanisms.

One of the objects of the invention is to provide improved means for supporting the valve rocker `which greatly facilitates valve adjustment and lubrication of the rocker, and is highly adapted' for use with stamped sheet metal rock ers of low cost manufacture.

Another object of the invention is to yprovide valve rocker supporting means arranged independently for each rocker and in which the push rod, valve stern and a stud anchored to the cy1in der head all cooperate with each other in a new and novel manner.

These and other yobjects are attained in accordance with my invention by the structures hereinafter described and shown in the drawings, in each modification of which a rocker of generally channel shape section is provided which bears downwardly at opposite ends upon the push rod and valve vstem and is fulcrumed intermediately .of its ends by means of a vstud fixedly anchored at one end to the cylinder head and extending through the rocker to lprovide .a bearing seat about which the rocker may oscillate during reciprocation of the push rod and valve.

In the drawings:

Figure '1 is a view partly in section and partly in elevation showing a portion of an internal combustion engine incorporating a valvev rocker with supporting and lubricating means in accordance with one form of my invention, and wherein the rocker is maintained in its proper plane of oscillation by the push rod which in turn is guided 'by the engine frame structure.

Figure 2 is a View similar to Figure 1 but showing a modied form of rocker supporting stud and also a diierent arrangement for `restraining rotation of the rocker about the stud axis.

Figurev isa sectional view taken substantially on line '3-3 of Figure 2.

Figures 4 and'5 are views similar to Figure 2 but showing successively modiiied forms of the rocker supporting stud.

Figure '6 is a view similar to Figure 2 but showing a still further modified form of the rocker supporting stud and an alternative means for lubricating the rocker pivot bearing.

'Figure '7 -is anenlarged detail elevational view taken rfrom line 1-101" Figure-6.

'Ivnthefdrawings there is shownfan engine frame structure of conventional overhead valve type including a cylinder block i and a cylinder head 2. Slidably guided for axial reciprocation `in the bore 3 of the cylinder head is the stem 4 of a poppet valve 5 the upper end 6 of which projects above the cylinder head, and similarly guided in the bore l' of the head is a push rod 8 which is disposed laterally of the valve stem 4 and has its upper end 9 also projecting above the cylinder head. The lower end Iii from the push rod -a'buts the upper end of a valve tappet Il which is -slidably guided for axial reciprocation in the tappet bore i2 provided in the cylinder block I. A cam i3 is shown on which rests the lower end vof thetappet il and whose shaft lll is rotatively-driven in any desired man-ner (not shown) to eiect reciprocation of the tappet and push rod.

Operatively connecting the push rod and valve stem is a valve rocker l5 having arms I6 and Il overlying and resting upon the upper ends 9 and t of the push rod and valve stem, respectively. Adjacent the outer end of its arm I6 thebottom ysurface of the rocker is spherically dished'fto socketably receive the push rod upperend 9 in bearing relation, andintermediate the `push rod and `valve the rocker l5 is provided on the upper surface of the rocker with a spherically dished bearing surface i3 which socketably receives a washer i9 having a correspondingly shapedbottom ysurface forming a seat for the rocker. Centrally of the bearing surface I8, the yrocker is provided with an aperture 20 through which extends an elongated member 2| in the form of'a stud having its lower end iixedly anchored as by a press t in the hole 22 in the cylinder head and provided at its upper end with a threaded nut23 which serves to retain the washer I9.

During the lift vstroke of the cam i3 the upward movement of the push rod will cause the turn stroke, the force of the spring '2.5 will drive the rocker counterclockwise about vthe washer I9 and effect the return of the push rod. Since there is at all times an upward thrust exerted upon each end of the rocker the vbearing suriace I8 is maintained in contact at all times with the washer i9 and the rocker is restrainedroni This.

rotation about the axis of the stud 2i. manner of 'iulcruming the rocker ,enabler-Itho rocker to be formed as a sheet 'metal stamping;- having, as shown, a generally channel'sliapedlI section. The web 26 of the channel has an upwardly projecting embossment 2l which socketably receives the upper end 9 of the push rod and a downwardly projecting embossment 23 forming the spherical bearing surface it and terminating in the aperture 2G. With the push rod S slidably guided in the bore 'I of the cylinder head as shown in Figure l, this socketed engagement of the push rod upper end 9 serves to prevent rotation of the rocker about the axis of the stud 2i in operation, and accordingly the web 26 need have only sliding contact with the valve stem upper end Ii. The small lateral oomponent of movement of the push rod upper end 9 in following the rotational movement of the rocker arm i6 has been found not to cause any objectionable binding in the bore l.

As means for lubricating the bearing surface I 8, I provide the stud 2I with a longitudinal passage sil which extends from the lower end of the stud and connects with a radial passage 3l leading outward to the interior of the washer I9 from which the oil passes through one or more drilled passages 32 provided in the wall of the Washer I9. The oil as it passes from between the bearing surface i8 and the washer l@ will escape through the aperture 2t around the stud 2| and flow downward onto the cylinder head from which it lubricates the push rod guide bore l. Any oil in excess of that which can drain through the aperture 2@ and which tends to collect on the upper surface of the rocker channel web will drain down through the hole 2S provided for that purpose. Oil may be supplied to the passage 30 from the hole 22 under pressure from a gallery 33 running endwise of the engine and communicating with the lower end of the hole 22.

Adjustment of the valve clearance is made by screwing the nut 23 further on or olf the stud 2 i. To facilitate such adjustment the nut 23 is preferably of the self-locking type requiring but a single wrench for` adjustment on the stud 2l. A Belleville spring washer 34 is preferably provided between the nut 23 and washer I9 to eliminate lash in the valve train throughout the operating cycle.

A rocker cover 35 of conventional inverted channel shape is shown enclosing the top of the cylinder head ii and sealed thereto by the usual gasket 36. Also in conventional manner, the valve spring 25 transmits its thrust to the valve stem through a retaining washer 3l, The lower end of the valve spring abuts an annular Belleviile spring 3B which has a dished configuration as shown in Figure 1 when the valve is closed but during valve opening collapses into mating engagement with the cylinder head, and in so doing serves both to damp surge of the valve spring 25 and to temporarily trap surface oil between the Belleville spring and the cylinder head during av portion of each valve opening stroke, whereby the Belleville spring and hence the lower end of the valve spring are alternately restrained and allowed to rotate relative to the cylinder and intermittent rotation of the valve is obtained.

in the modication of my invention shown in Figure 2 the push rod is not slidably guided in either the cylinder head 2 or the cylinder block I and hence does not serve to restrain the rocker 40 from rotation about its stud I. In lieu thereof the rocker i8 has its web embossed upwardly opposite the valve to provide a recess 42 in which is received the upper end 6 of the valve stem. This recess i2 extends longitudinally of the d rocker de to accommodate relative sliding movement between the stem and the web of the rocker.

Also in Figure 2 a somewhat different form of stu-d is used for supporting the washer I9, this stud ai having an externally threaded lower end portion i3 which screws into a threaded hole 45 in the cylinder head, and an integral enlargement it at the upper end of this threaded portion which serves as a jam nut for the stud in securing it to the cylinder head.

In Figure 4 I have shown a similar arrange- -ment to that of Figure 2, i. e. with the push rod unguided in the engine structure and the valve stern keyed to the rocker for maintaining it in proper registry, but with a modified form of the rocker supporting stud shown in Figure l. This particular stud 5i is formed from tubing stock and has an upper shank portion similar to the stud 2i of Figure 1 and an expanded lower end portion 52 having a pressed nt in an enlarged hole `53 of the cylinder head.

In Figure 5 the structure is the same as Figure 2 with the exception of employing a modified form of stud 5). The stud 6] has an externally threaded shank iii, its threads being of the selflocking type and engaging a threaded hole 62 in the cylinder head. The head 63 of this stud directly engages the hearing surface I8 of the rocker, eliminating the use of the washer I9 of Figure l. The surface of the head $3 facing the bearing surface l is spherical in contour and is relieved by an annular groove 643 in communication with the radial oil passage 3l. Suitable wrench engaging means such as a conventional screw driver slot or socket (not shown), are provided in the upper end face of the head Si).

En Figure 6 an alternative means for supporting the washer I9 is shown in the form of a cap screw "it, the head ii of which serves as an abutment for the washer and the shank l2 threads into the cylinder head, A jam nut 'I3 is provided for locking the stud against displacement in operation. Also shown with this rocker mounting arrangement is an alternative form of lubrication 4 for the rocker bearing surface I8 in the form of ably formed by an upwardly presenting channel.

.. in a position elevated with respect to the rockers d associated with the various cylinders of the engine. Opposite each rocker the iiange 'I8 of the stamping 'I6 is turned outwardly and spaced from the inner surface of the rocker cover to provide a trough or lip l over which oil may spill from the gallery and drop on to the web 0f the rocker and thence now to the bearing surface I8.

It will of course be understood that the various rocker supporting studs, means for restraining the rocker against rotation axially of the stud, and the rocker lubricating systems Adescribed above and shown in the drawings may be rearranged in different combinations from those suggested, all within the scope of the appended claims.

, I claim:

1. In combination, a cylinder head, a poppet valve and a push rod each axially reciprocable in and terminating externally of the cylinder head, a rocker having one side in abutment'with aeeassr 5, one end: each of the valve land push rodv and an aperture intern'iedi'atev the valve and push rod, a bearing surface on theoppositeside of the rocker adjacent aperture, an elongated member xed atene: end tothe cylinder head and extendthrough. said aperture, a seat on the member abutting.` said bearing surface on the rocker, said bearingsurface and: seat having cooperating. configurations. and said member having clearance in said aperture.` accommodating oscillation of, the. rocker about an axis intermediate the valve andl push rod during, simultaneous axial movements ci the valveand push rod in opposite. directions..v

2. In an internal combustion engine, a, cylinder head', a; poppet: valve havingv a stem slidably sup-l ported in the cylinder head for axial' reciproca.-

tion, an axially reciprocahley push rod arranged generally' in the samev plane with the valveY stem, alrocker for transmitting axial thrustA between the valvef stem andthe push rod, said rocker having surfaces on one side engaged respectively by the,

valve, stem and push rod and a bearing surface on its opposite side intermediate the valve stem andi push rod, said bearing surface having a curvature in a planelongitudinally of the rocker, and means journaling said bearing surface having a shank extending through the rocker and anchored` to the cylinder head.

3. In an internal combustion engin@ a cylinder head, a poppet valve having a stem slidably supported by' the cylinder head for axial reciprocation, a push rod disposed laterally of the valve stem and arranged to axially reciprocate in opposite phase to said valve, a rocker having surfaces on one side in respective driving engagement with the push rod and valve, a Washer about which the rocker may pivot in response to reciprocation of said push rod and valve, said washer and rocker having coacting bearing surfaces on the opposite side of the rocker, and a stud fixedly securing said washer to the cylinder head.

4. In an internal combustion engine having a cylinder head, a poppet valve mounted for axial reciprocation therein, an axially reciprocable push rod arranged laterally of the valve, and a rocker for transmitting reciprocable move ments between the push rod and valve, said rocker having oppositely extending arms resting on the upper ends of the valve and push rod respectively and an upwardly presenting socket intermediate said arms, a stud nxedly anchored at its lower end to the cylinder head and extending into said socket, and a Washer on said stud rotatively journaling the rocker in said socket for oscillatory movement of the arms in response to reciprocation of the valve and push rod.

5. In an internal combustion engine, a cylinder head having a pressure fed oil gallery, a stud anchored at one end to the cylinder head, a Washer on the opposite end of said stud provided l with a spherical seat surface opposite the cyl- G inder head, said stud having an internal oil passage connecting said seat surface and oil gallery, and a valve rocker having an opening intermediate its ends loosely embracing said stud and an annular spherical bearing surface surrounding said opening and socketably receiving said seat surface.

6. In an internal combustion engine, a cylinder head, a reciprocable poppet valve having a stem guided in the cylinder head, a push rod reciprocable relative to the cylinder head and valve, a rocker operatively connecting the valve stem and push rod, an elongated member having threaded engagement at one of its ends with the cylinder head v and extendingf through; the rocker intermediate the valve stem and.' push rod, and; means on the extended endlofsai'd member constituting a seat oscillatably. supporting the rockerv during reciprocation of the valve and push` rod.

'7'. In combination, a cylinder head, a poppet4 valve and apush rod reciprocable relative toy and; terminating exteriorly of the cylinder heads, a; rocker for transmitting thrust between the push rod' and valve, sai'droclrer'being of generally upwardly presenting channel section with the channelfweb having upwardly'projecting embossments; socketably receiving the upper ends ofthe push: rod' and valve respectively and a downwardl'yprojecting embossmentl located intermediate the. push rod4 and valve, said downwardly projecting embossment having a. spherical' bearing surface on its'upperside andi terminating in an aperture, an annulary washer having a spherical bottoml surface fitting said bearing surface, a tensioni member extending through the washeiand aper-A tureand having a press i'lt at its lower end in the cylinder head, and a Washer retaining nut threadedly engaging theupper end of said tension mem-- ber, said tension member having connecting lon.- gitudinal and radial passagesv therein for conducting; lubricant from the cylinder'head to said bearing surface.

8'. In combination, a cylinder head, a poppet.l valve and a push rodl reciprocable relativek to the cylinder head, a rocker having surfaces: on oneside in. one-way thrust transmitting engagement with the valve and push rod respectively, said rocker having an aperture intermediate the valve and push rod and a bearing surface adjacent said aperture on the side of the rocker opposite said first mentioned surfaces, a stud having a press fit at one end in the cylinder head and extending through the aperture in the rocker, a washer on the stud journaling said rocker bearing surface, and a washer retainer threadedly engaging the stud.

9. In combination, a cylinder head, a poppet valve and a push rod reciprocable relative to the cylinder head, a rocker having surfaces on one side in one-way thrust transmitting engagement with the valve and push rod respectively, said rocker having an aperture intermediate the valve and push rod and a bearing surface adjacent said aperture on the side of the rocker opposite said first mentioned surfaces, a stud. having externally threaded portions adjacent its respective ends, one of said threaded portions being screwed into the cylinder head, a shoulder integral with the stud and abutting the cylinder head, a Washer embracing the stud and journaling said rocker bearing surface, and a nut on the other of said stud threaded portions thrustably supporting said washer.

l0. The combination With a cylinder head, a reciprocable poppet valve having a stem guided in the cylinder head, a push rod reciprocable relative to the cylinder head and valve, and a rocker operatively connecting the push rod and valve stem, of fulcrum means for the rocker, said means comprising a stud ixedly anchored at one end to the cylinder head and extending through the rocker intermediate the push rod and valve stem, a spherical bearing surface on the rocker, and a spherical seat on the stud journaling said rocker bearing surface.

11. In combination, a cylinder head, a push rod and a valve axially reciprocable therein and terminating above said cylinder head, a rocker of upwardly presenting channel section having a web resting on the upper ends of the push rod and valve, a downwardly projecting embossment formed in said web intermediate the push rod and valve, said embossment having a spherical bearing surface on its upper side and terminating in an aperture, an annular washer having a spherical bottom surface iitting said bearing surface, a cap screw extending through said washer and aperture with the head of the screw abutting the upper surface of the washer and the shank of the screw threadedly interengaging the cylinder head, a jam nut on the screw shank bottoming against the cylinder head, a rocker cover of inverted channel shape having side walls engaging the cylinder head laterally of the push rod and valve, a generally upright channel member having side walls terminating in abutment with the inner surface of said rocker cover and forming therewith an oil gallery above and transversely of the rocker, one of said upright channel member side walls having a portion opposite the rocker terminating in spaced relation with said rocker cover inner surface to permit oil to flow out of said gallery for gravitation to said rocker bearing surface, and a tube extending into the cylinder head from said gallery through which oil may be delivered under pressure to the gallery.

12. In an internal combustion engine, an engine structure including a cylinder head, said structure or cylinder block having a tappet bore, said cylinder head having a push rod bore aligned with said tappet bore and a valve stem bore dis- 8 posed laterally of said push rod bore, a cam operated tappet slidably guided for axial reciprocation by said tappet bore, a push rod slidably guided for axial reciprocation by said push rod bore, one end of said push rod thrustably abutting the tappet and the other end ezt-ending above the cylinder head, a poppet valve having a stem slidably guided for axial reciprocation by said valve stem bore and having an end terminating above the cylinder head, an elastic member biasing said valve stem upwardly relative to the cylinder head, a rocker having oppositeiy disposed arms overlying and resting on the upper ends of the push rod and valve stem respectively, an upwardly presenting spherical bearing surface on the rocker intermediate the push rod and valve, a stud extending loosely through the rocker at said bearing surface and fxedly anchored at one end to the cylinder head, and a washer on said stud providing a downwardly presenting spherical seat for said bearing surface.

CLAYTON B. LEACH.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,265,735 Brush May 14, 1918 1,636,903 Dodge July 26, 1927 1,659,528 Hosterman Feb. 14, 1928 1,877,051 Read Sept. 13, 1932