US3410366A - Rocker arm lubrication system - Google Patents

Description

6 J. R. WINTER, JR 3,410,366

ROCKER ARM LUBRICATION SYSTEM Filed June 14, 1965 2 ee sl INVENTOR. $757! X M'rzfazfi:

Nov. 12, 1968 J. R. WINTER, JR 3,410,366

ROCKER ARM LUBRICATION SYSTEM Filed June 14, 1965 2 Sheets-Sheet 2 INVEN TOR.

United States Patent 3,410,366 ROCKER ARM LUBRICATION SYSTEM John R. Winter, Jr., 4276 S. Shore Drive, Watkins Lake, Pontiac, Mich.

Filed June 14, 1965, Bar. No. 463,480 6 Claims. (Cl. 184-6) ABSTRACT OF THE DISCLOSURE Rocker arm levers for the overhead valves of internal combustion engines of the type wherein the engine block and rocker arm are inclined to the horizontal and which are provided with a forced feed lubrication system, are provided with oil passages which tend to offset gravitational elfects upon oil flow, the passages leading to the lower or downwardly inclined ends of the rockers being smaller than the passages leading to the upper ends. In addition, the outer extremities of the passageways, in each instance, deliver the oil to the high side of the valve stem or push rod, as the case may be, so that the oil discharged toward the valve stem and push rod flows on to the higher sides of the engaging surfaces, rather than flowing away from such engaging surfaces.

The present invention relates to the construction of rocker arms for internal combustion engines of the overhead valve type, and particularly to an improved rocker arm especially adapted to actuate the overhead valves of engines having inclined blocks. The invention is illustrated in an embodiment adapted for use on engines of the type wherein the upper ends of the valve stems are positioned higher than the upper ends of the push rods, and also in an embodiment adapted for use in an engine wherein the upper ends of the push rods are at a-higher elevation than the upper ends of the valve stems.

An important object of the invention is to provide effective, positive and properly proportioned lubrication to both ends of such rocker arms at all times and under all engine operating conditions.

Another object is to provide improved rocker arms of the indicated character which are of great mechanical strength and reliability and which may be economically mass-produced to high standards of uniformity.

Other objects and advantages will become apparent upon consideration of the present disclosure in its entirety.

In the drawing:

FIGURE 1 is a side elevational view of a rocker arm constructed in accordance with the present invention illustrating the same in installed position and showing fragments of associated engine parts;

FIGURE 2 is a side elevational view of my improved rocker arm on a larger scale;

FIGURE 3 is a top plan view of the arm;

FIGURE 4 is an elevational view of the arm from the valve end;

FIGURE 5 is a sectional view taken substantially on the line VV of FIGURE 2, and looking in the direction of the arrows;

FIGURE 6 is a side elevational view similar to FIGURE 1, showing a modified construction;

FIGURE 7 is a plan view of the blank for the rocker arm of FIGURE 6 after performance of an initial forming operation but prior to folding;

FIGURE 8 is a cross section of the valve end of the arm, taken substantiallyv on the line VIII-VIII of FIG- URE 6 and looking in the direction of the arrows, and

FIGURE 9 is a bottom plan view of the bottom portion of the arm at the pushrod end.

Referring now to the drawing, my improved rocker arms are preferably formed of sheet metal, although it will 3,410,366 Patented Nov. 12, 1968 be recognized that the principles of the present invention are applicable to rocker arms fabricated by other means. The body 10 of the preferred arm illustrated in FIGURES 1-5 is formed of a single blank of sheet metal folded upon itself to provide two laminae. As isbest indicated in FIG- URE 3, the mid-section of the blank which forms the body of the arm is wrapped around the stem 12 of a push pin having a head 13 which constitutes the valve actuating element of the arm. The opposite end of the arm, which is to be actuated by the pushrod, is Wrapped around the stem 14 of a ball stud having a head 15 which is to be engaged and actuated by the pushrod. The internal opening for the ball stud may be properly tapped to receive a lockingtype threadably adjustable stud having a ball portion 15 at its lower extremity and which is adapted to be engaged and actuated by the engine pushrod 16. The pad portion 13 at the lower extremity of the push pin 12 engages and actuates the valve stem 18 when the arm is installed, as will also be appreciated.

It will be understood that while the end portions of the body are described as wrapped around the stems 12 and 14, the looped portions which retain such stems are ac tually preferably formed prior to installation of such stems, and are initially somewhat smaller than the stems, so that when pressed into place the push pin will be tightly retained by a yieldable press fit, and so the threads of the arm and ball stud will be tight enough to frictionally retain the ball stud in any adjusted position. If the engine is provided with valve gear take-up means such as hydraulic lifters, the ball stud may also be pressed into place rather than threaded, as will be recognized and as is illustrated in the second embodiment presently to be described.

The laminations of the arm may be secured together by suitable known means, as for example, by the rivets 19, 20, the latter also extending through a third thickness formed by the extremity of the blank which is wrapped around the ball stud opening area.

The central portion of the arm, which is wider in its vertical dimension to define the hub portion of the arm, is provided with cylindrical oppositely out-turned necks 21, 22 within which a bearing bushing 25 is fitted and tightly held as by a tight but flexible press fit. The securance of the bushing and other parts may, if desired, be augmented by welding or brazing, depending upon the preference of the designer, but I have found that this is not necessary where the metal is worked cold and no heat which would draw the temperature of the metal is employed. In the area around the bearing bushing 25, between the neck sections 21, 22 of the hub portion of the arm, the outward bending of such neck portions provides a separation between the laminae of annular form extending entirely around the bushing and defining a V- sectioned groove 26. An oil hole 28 extends through the wall of the bearing bushing midway of its length providing oil conductive communication between the shaft 29 and the oil groove 26 and the shaft is appropriately drilled in such manner as to provide oil conductive communication from the force feed lubrication system as will be recognized.

The oil supply for the two ends of the arm is taken from the annular internal groove 26 through an angularly upwardly and forwardly extending channel 30 formed in the arm by inwardly facing embossments 32 pressed in the blank so that the channels are in the interior when the blank is folded back upon itself. At its upper end the channel 30 communicates with a centrally positioned longitudinally extending groove 33 on the top of the arm extending to the valve end, and with a shallower groove 35 extending to the pushrod end. As best shown in FIGURE 5, the grooves 33 and 35 are defined by outwardly pressed portions at the upper margins of the laminae. It will be recognized that all of the channels, both internal and those for the top, can be formed in the blank before it is folded.

At the valve end the larger top channel 33 communicates with angularly forwardly and downwardly extending channels 36 formed in the interior surface and which extend around the shank of the push pin 12 and downwardly to the lower extremity of the retaining loop 11 for the push pin. At its lower surface the outer extremity of the loop is notched upwardly, as indicated at 37, providing a space above the head 13 of the push pin 12 constituting an outlet for the oil channels 36. The outlet defined by notch 37 is located at the highest part of pad 13 when the arm is installed. The inner extremity of the loop 11, in the general areas designated 38 where said loop joins the fiat portions of the laminae, are tightly pressed inwardly to eliminate any possibility of an opening at the low end of the pad which could permit escape of oil when pad portion 13 is pushed into position against the bottom of the loop. Thus oil can only escape through the hole 37 at the valve end.

The other or pushrod extremity of the top channel 35 communicates with a V-shaped opening 40, defined by the outwardly turned portion of the Wrapped laminae which defines the inner part of the loop 41 for the ball stud 15. The other lamina which is covered by the tab portion 17 and which abuts the stem of the ball stud, may be angularly relieved in the same area to provide a larger channel for downfiow of oil at 40, as indicated in FIGURE 3.

When the arm is installed in slanted position in a typical installation, as indicated in FIGURE 1, oil which is forced from the riser channel 30 under pressure from the force feed lubrication system of the engine, is reduced to atmospheric pressure when it reaches the top channels 33 and 35. In View of the fact that the hole 30 discharges the oil at a substantial distance from the axis of oscillation of the arm which axis is located at the center of the hub, centrifugal force tends to propel the oil outwardly in the deeper channel 33 toward the valve end, and a proper metered quantity of oil is thus delivered to and flows downwardly through the channels 36 and out from the hole 37 to the high side of the head or pad 13 of the push pin. It then flows downwardly over the high side of the pad 13, and, adhering to the metal surfaces, flows downwardly beneath the head to lubricate the engaging surfaces of the push pin and valve stem. A portion of the oil also flows downwardly under the influence of gravity along the downwardly inclined top channel 35 leading to the pushrod end of the arm, and thence downwardly through the internal channel 40 to the side of the ball 15 nearest the hub, escaping from the lower end of channel 40 at the high side of the ball. Thus the oil adhering to the ball flows downwardly along its high side and is effectively delivered to the engaging surfaces of the ball and pushrod to lubricate the latter. Controlled and metered quantities of oil are thus available at both such surfaces and may overflow and run downwardly along the shanks of the pushrods and valve stems to provide desired quantities of lubrication for the latter elements.

It will be recognized that the shallower depth of the top groove 35 provides at its juncture with the riser hole 30 a partial dam tending to prevent flow of more than a limited quantity of oil from the riser hole into the channel 35, and the elfect of centrifugal force also limits the quantity of oil which can thus flow towards the lower end of the arm. This is of great importance because of the fact that while a certain amount of lubrication of the pushrod is essential, over-supply of oil to the pushrods as well as to the valve stems should be avoided. In a highly successful rocker arm of the indicated construction having the engine block tilted 30 from the vertical, the top channel 33 leading to the valve end has a diameter of 0.060 inch, and channel 35 to the pushrod end is of .046 inch diameter. It will be appreciated that th forces which are effective to control the oil distribution can be altered both by changing the sizes of the top channels, and by changing the inclination of the riser hole 30 to accord with the conditions obtaining in the particular engine for which the arm is designed.

With the construction shown, it has been found practical to permit slightly more oil to flow through the riser hole than is actually needed. The excess oil then flows over the side of the arm and drips from the lower portion of the arm without reaching the extremities.

In the modified construction shown in FIGURES 6 to 9 inclusive the channels which deliver the oil to the ends of the arm are entirely internal, and the rocker arm is further modified to adapt it particularly to installation upon an engine block which slopes in the opposite direction from that indicated in connection with the first embodiment. The rocker arm of FIGURES 6-9 is adapted for installation upon a V-type engine wherein the upper ends of the pushrods are higher than the upper ends of the valve stems. In such engines, over-oiling at the valve stem is highly undesirable, and the problem of providing adequate and reliable lubrication while nevertheless preventing over-oiling of the valve stems, in a simple and economical manner, has been a troublesome one.

In my improved rocker arm shown in FIGURES 6-9, the oil is taken from the shaft 29 through the hub of the arm in similar fashion, and is delivered from the annular V-sectioned supply groove 26 in the hub to two internal channels formed in the body 50 of the arm. One such internal channel, designated 51, extends to the valve end of the arm, and another, designated 52, extends to the pushrod end. It will be observed that the internal channel 51 leaves the hub groove 26' at a relatively low point, extends angularly upwardly toward the top of the valve end of the arm, and terminates at that side of the hole 11' for the valve actuating push pin stem 12 which is nearest the hub. The other internal channel, 52, departs from the annular supply groove 26 at as high a position as is practical, and extends angularly downwardly to and entirely around the interior of the loop 41 which accommodates the stem 14 of the push pin ball stud. At its outer lower end the terminus of the channel 52 is provided with a downwardly opening enlargement 54 on the farther side of the stem and ball. The portions of the loop 41 on the side toward the hub are pressed tightly against the stem of the stud, so that when the arm is installed, little or no oil can escape at the low side, substantially all of the flow occurring through the opening 54 at the high side, thereby insuring flow over the engaging surfaces as well as downwardly on the pushrod.

In addition, the internal channel 51 is of reduced cross section and is designed to a size which will, under the prescribed pressure conditions and requirements of the particular engine, permit only a limited quantity of oil, adequate to lubricate the valve stems without an excess, to reach the valve end of the arm. The passage 52 to the pushrod end is of larger size. In a successful rocker arm constructed in accordance with this invention passage 52 has approximately four times the cross sectional area of passage 51. It will be recognized that requirements may vary under the different conditions that may exist in different engines, such as differences in oil pressure and other factors, but passage 52 should be large enough to facilitate flow of an adequate quantity of oil through this passage. Passages 51 and 52 coact with the orifices in the hub and shaft to meter the flow to both ends of the arm.

With respect to the mechanical construction of the rocker arm of the second embodiment, it will be seen that it may also be conveniently formed of sheet metal, the body of the arm being formed from a single blank as shown in FIGURE 7. On one side the blank is provided with integral foldable tabs or extensions 55, 56, 57 and 58. The portions of the blank which form the two laminations are joined at the valve end, and are folded together in aligned relation around and to define the looped area 11' for the stern of the valve actuating push pin, and are pressed and held tightly together, the tab portions 55-58 then being folded down to tightly secure the two laminae together and hold the parts in alignment. The engagement between the flat inner surfaces of the two laminations is so tight as to form an oil seal preventing escape of oil except through the passages. The passages 51, 52 are preferably defined by registering inwardly facing embodiment in both halves, as indicated.

While it will be apparent that the preferred embodiments of the invention disclosed are well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

1. In an engine rocker arm installation comprising a lever having a hub portion defining a fulcrum and having a pair of arms extending in opposite directions from the hub portion, one arm being inclined upwardly and the other downwardly, and means for feeding oil to the interior of the hub portion, internal riser passage means extending from the interior of the hub portion angularly outwardly and upwardly toward the outer end of the upwardly inclined arm and having an open terminus at the top of such arm at a position between said outer end and the hub portion, an open-topped oil-conductive channel extending along said top of the arm from such terminus to oil-conductive communication with said outer end of said arm, and an oil-conductive channel of lesser efiective cross section leading from said terminus to a position near the outer end of the downwardly inclined arm.

2. In a construction as defined in claim 1, additional channel-defining portions extending downwardly from the outer end of said open-topped channel to the lower portion of the outer extremity of said upwardly inclined arm.

3. A construction as defined in claim 2 wherein said outer end of said upwardly inclined arm is in the form of a loop, and an abutment member is retained in said loop, said downwardly extending channel-defining portions including a groove formed in the internal surface of said loop around and downwardly along said abutment memher.

4. A construction as defined in claim 2 wherein said second mentioned channel is also open-topped, and passage means extending downwardly from said second mentioned channel to a lower portion of said downwardly inclined arm spaced from the extreme end of such downwardly inclined arm.

5. A construction as defined in claim 4 having the top edge of the lever extending continuously along the arms and over the top of the hub, said two open-topped channels being in communication with opposite sides of said terminus of the riser passage and the second mentioned.

open-topped channel being shallower in its vertical depth than the first mentioned open-topped channel, whereby the side of the riser passage closest to the shallower channel tends to block flow of oil into the latter.

6. A rocker arm for an engine for transmitting movement from a valve actuator to a valve, said rocker arm comprising a lever having a portion defining a fulcrum and arm means extending from said fulcrum, valve engaging pad means on said arm means for engagement with an associated valve for operating the valve upon pivotal movement of said lever about said fulcrum, valve actuating pad means on said arm means for engagement with the valve actuating means for etfecting pivotal movement of said lever about said fulcrum, said lever being adapted to be positioned in the engine when in use at an angle to the horizontal with one of said pad means being disposed at a higher level than the other of said pad means, and oil passage means formed in said lever for delivering lubricating oil to each of said pad means, said oil passage means terminating in a valve pad lubricating opening and a valve actuating pad lubricating opening in said lever arm means, each of said lubricating openings being disposed on one side of the respective pad means and at a higher level than the respective pad means when said lever is positioned in use in the engine for assisting in gravity induced delivery of lubricant from said passage means through said lubricating openings to the respective of said pad means and the associated valve train element.

References Cited UNITED STATES PATENTS 2,448,989 9/1948 Leake 184-6 2,509,661 5/1950 Winter 745 19 X 2,563,699 8/1951 Winter 184-6 X 3,116,647 1/1964 Leake 184-6 X FOREIGN PATENTS 888,093 1/ 1962 Great Britain. 489,484 1/ 1954 Italy.

LAVERNE D. GEIGER, Primary Examiner. E. J. EARLS, Assistant Examiner.

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