US2123681A

US2123681A - Internal combustion engine-rocker arm lubrication

Info

Publication number: US2123681A
Application number: US42005A
Authority: US
Inventors: Andrew V D Willgoos
Original assignee: United Aircraft Corp
Current assignee: Raytheon Technologies Corp
Priority date: 1935-09-25
Filing date: 1935-09-25
Publication date: 1938-07-12
Anticipated expiration: 1955-07-12

Description

July 12, 1938. A. v. D. WILLGOOS 2,123,681

INTERNAL COMBUSTION ENGINE-ROKER ARM LUBRICATION Filed Sept. 25. 1935 s Sheets-Sheet 1 2a 42 40 E 1 1 32 4 Z I INVENTOR. flndPEWVZZW/[qaas ATTORNEY 3 Sheets-Sheet 2 Q INVENTOR. flndrawviqwfi 00.9

A. v. 0. WILLGOOS Filed Sept. 25. 1935 INTERNAL COMBUSTION ENGINE-ROCKER ARM LUBRICATION July 12, 1938. v; D. WILLGOOS 2,123,631

INTERNAL COMBUSTION ENGINE-ROCKER ARM LUBRICATION Filed Sept. 25, 1955 s Sheets-Sheet 3 IN VEN TOR. I

. A TTORNEY Patented July 12, 1938- INTERNAL COMBUSTION ENGINE-ROCKER.

ARM LUBRICATION Andrew D. Willgoos, West Hartford, Conn., as-

signor to United Aircraft Corporation, East Hartford, Conn., a corporation of Delaware Application September 25, 1935, Serial No. 42,005

8 Claims.

This invention relates to improvements in internal combustion engines and has particular reference to improved means for lubricating the valve operating mechanism of such an ens ne.

One object of the invention resides in the provision of means for supplying lubricant from the engine lubricating system'to the. valve operating mechanism.

A further object resides in the provision of means for definitely limiting the amount of lubricant supplied to the valve operating mechanism and for removing thelubricant therefrom and returning the same to the engine lubricating System so that thevalves will not be flooded by an excessive quantity of lubricant.

Other objects and advantages will be hereinafter pointed out or will become apparent as the description proceeds.

In the accompanying drawings, in which like reference numerals are used to designate similar parts throughout, there is illustrated a suitable mechanical embodiment of what is'now considered to be the preferred form-of the invention.

25 The drawings, however, are for the purpose of illustration only and are not to be taken as limiting the invention, the scope of which is to be measured entirely by the scope of the appended claims.

In the drawings, Fig. 1 is a side elevational view of an internal combustion engine such as an airvcooled radial engine conventionally used tofurnish power for aircraft, certain portions of the engine being broken away to illustrate the 85 application of the idea of the invention thereto.'

Fig. 2 is a sectional view on an enlarged scale showing a fragmentary portion of the engine illustrated in Fig- 1 and a portion of the valve op-- erating mechanism including the valve rocker 4 arm in its operative position insuch fragmentary portion of the engine.

Pig! 3 is a sectional view'on an enlarged scale showing a fragmentary portion of the engine illustrated in Fig. 1 and the valve tappet and 45 tappet guide in its operative position in such fragmentary portion of the engine.

Fig. 4 is a front elevational view of the engine illustrated in Fig. 1 showing means for returning oil from the vicinity of the engine 50 valves back to the engine lubricating system and also showing in a broken away portion of the engine, means for supplying oil from the engine lubricating system to the valve operating mech- Referring to the drawings in detail, in Fig. -1

jects a power shaft, not illustrated, upon the projecting end of which is mounted a propeller generally indicated at. l8. The rear section is provided with a fuel distributing chamber from which manifolds 22 lead to the intake ports 24 of the. cylinders 28 radially secured upon the substantially annular crankcase Hi. The cyl'. inders are also provided with exhaust ports, not illustrated, in the conventional manner. Each cylinder 26 is provided with a pair of valve rocker arm boxes 28' and 30, preferably, though not necessarily, formed integrally with the cylinder heads. The intake and exhaust ports of the cylinders are opened and closed in timed relation to the operation of the engine by suitable power -shaft speed, suitable valve tappets as indicated at 38 rocker arms as indicated at 40 mounted in the rocker arm boxes 28 and an by means of suitable bearings 42, and push rods,

as indicated at 44, interposed between the tap pets 38 and the rocker arms 40 to transfer movements of the tappets 38 induced by the action of the cam 36 to the rocker arms 40 and through the rocker arms to the stems of the valves 32 to cause the valves to open and close the intake and exhaust ports in timed sequence to the operation of the engine.

At the bottom of the crankcase If] there is provided an oil sump 45 into which the oil which has been forced under pressure through the bearings and other working parts of the engine flows under the influence of gravity, The oil is removed from the sump 4G through'a suitable conduit 48 and a scavenging pump, not illustrated, and returned to a tank or other suitable reservoir from which it is led to the oil pressure pump and returned under pressure to the lubricating system of the engine.

In accordance with the idea of this invention, a second oil sump 50 is secured to the crankcase Ill directly below the oil sump 4G for a purpose to be presently described. This secondary oil sump 50 is also provided with an outlet conduit 52' leading to a suitable scavenging pump by means of which the oil is returned to the oil tank or reservoir and the sump maintained in a dry condition.

This oil sump 58 has a suilicient capacity below the rocker boxes of the bottom cylinders to receive all of the oil which drains from the rocker boxes of the various cylinders when'the engine is stopped so that there is no tendency to flood the bottom cylinders.

Referring particularly to Fig. 2 it will be observed that each rocker arm is a lever of the first order in which the forces are applied to the opposite ends and the bearing 82 intermediate the ends acts as a fulcrum. The bearing 82 is preferably. an anti'friction bearing such as a ball bearing or roller bearing andis supported upon a pin 58 mounted at its opposite ends in the sides of the rocker arm box 28. At the valve end the rocker arm 88 is provided with a screw threaded aperture 58 within which is inserted an adjustable screw threaded plug 58 having a partly spherical depression in its lower end to receive a spherical flattened ball 88 which slides on the upper end of the stem of the valve 32. This plug 58 is locked in adjusted position by suitable means such as the lock nut 82. At its opposite end the rocker arm is provided with a cylindrical well within which is disposed a block 88 oi hardened material provided with a partly spherical depression which receives a partly spherical tip 86 secured upon the'upper end of the push rod 88. The push rod is tubular or provided with an axial bore as indicated at 88, and a channel I8 leads from the bore 68 through the tip 88. A

: corresponding channel 12 leads through the portion of the block 68 overlying the upper end of the tip 88 and communicates with a channel I8 leading through the'portion of the rocker arm 88 between the block 88 and the bearing 82. The

passage through the rocker arm is continued upon the valve side oi. the bearing 82 by means of a channel I6 which leads to. a slot I8 provided in the screw threaded wall of the aperture 86. From this slot' an angular channel 88 leads through the plug 58 to the surface of the tip 88.

Suitable branch channels

82 and 88 lead from the channel I8 into the interior of the, bearing 82 to provide a supply of lubricant to the interior of the bearing.

- from the above description it will be observed that lubricant, such as a suitable engine oil, may flow from the interior or the hollow push rod 88 through'the channel-I8 to the bearing between the-push rod tip seam the block 88 to lubricate this bearing and that some of the lubricant will continue to flow through the channels I2, I8, IS, the slot' I8 and the channel 88 to the bearing between the plug 88 and the ball 88 on the stem of the valve 82 to lubricate the bes ring between the plug 58 and the tip 88, andthat another portion of the lubricant will be diverted from the channel I8 through the

channels

82 and 88 to the interior of the 'antifriction bearing 82 to lubricate the elements of this bearing, thus providing complete lubrication ior all of the movable elements of the portions of the valve operating mechanisms contained in the

rocker arm boxes

28 and 88. Each rocker arm box is provided with an aperture-86 to allow access to the adjustable plugs 58 so that the valve operating mechanisms may be adjusted to provide proper clearance for the valves, and each of these apertures is covered by a suitable curved plate 88 secured to the rocker arm boxes'by stud bolts as indicated at 88. Suitable compressible gaskets 82 are interposed between the adjoining surfaces of the rocker arm boxes and the plates 88 to constitute an oil tight seal so that each rocker box is made an oil tight receptacle for receiving the oil flowing from the bearings included therein.

In Fig. 3 there is illustrated the valve operating mechanisms at the lower or inner ends of the push rods 88, such mechanisms include the cam 28 for operating the valve tappets 88. Each valve tappet 38 is slidably mounted in a suitable case I8 by screws or stud bolts 88 and is provided with a bifurcated lower or inner end within which is mounted a roller 88 which rolls upon the cam 88. The tappets 88 are hollow members provided with internal bores or recesses as indicated at I88 and.have open outer ends. The outer ends of the hollow tappets 88 are closed by push rod cups I82, each having a reduced portion fitting within the openv endof the tappet and an annular shoulder I88 resting upon the tappet end. Each of the cups I82 is provided with a partly spherical depression which receives the partly spherical bearing portion of the tip I88 on the lower end of the push rod 88. The tap-. pets 88 may be constructed in several diflerent ways. For. instance, the roller 88 may be mounted in the lower portion of the bore I88 as illustrated in Fig. 3, or the bore may be separated from the roller by a partition, thus providing a tappet in the form of a cup having continuous side and bottom walls in which case, lubricant.

to be fed to the interior of the push rod 88 may be introduced directly into the interior of the hollow tappet; In the form of tappet illustrated, however, it is obvious that unless a definite channel were provided the lubricant would flow out of the tappet through the opening around the roller 88 so, in order to provide a pressure feed of lubricant to the hollow push rod 88, there has been provided within the hollow tappet a plug I88 having a reduced end portion II8 fitting into a well provided in the inner surface of the cup or seat I82 and an enlarged end II2 which forms a seal between the plug and the inner wall of the hollow tappet. The plug I88 is provided with a concentric oil channel II8 which leads from a position adjacent to the inner end of the plug to the exterior of the reduced portion II8 fitting into the well provided in the lower of the cup member I82. From this well a channel H8 leads through the intermediate portion of the cup member to the end of a channel II8 which extends through the push rod tip I88 and communicates with the interior of thehollow push rod 88. The tappet guide 88 is provided with an annular channel I 28 from which a plurality of radial ports, as indicated at I22, ex-.

' tend through the wall of the guide. A port I28 in the tappet 88 comunicates with one 01 the ports I22. when the tappet is in the position illustrated in Fig. 2 with the roller 88 riding on the highest portion of the cam 88 and the port I28 communicates through a channel I26 with the lower end of the channel H8. The portion of the engine crankcase overlying the tappets 38 and the tappetguides 88 is provided with an annular manifold I28 which may be a groove or channel cut into the material of the crankcase or may be a separate tubular member attached to the engine structure, depending upon the construction of the engine to which the device of the invention is applied. Headers, as indicated at I88, lead from the manifold I28 toeach of the annu- .tappet guide 88 secured to the engine crank- 2,12aaa1 system of 'the engine so that lubricant under pressure is supplied to the manifold. From the manifold the lubricant flows through the various headers I30 to the channels provided in the tappet guides and from these channels through the ports I22 and I24 to the interior of the hollow tappet 38 or the interior of the plug I08, depending upon the type of tappets to which the invention is applied. In the device illustrated the oil flows through the port I24, the channels I26 and H4 and the channel H0 in the push rod seat I32 to the bearing between the push rod seat and the push rod tip I06 and from thence through the channel II8 to the interior of the hollow push rod from whence it flows by means of the channels above described to the various bearings in the valve end of the valve operating mechanism.

It will be observed that the port I22 in the tappet guide and theport I24 in the tappet are so related that a passage for the oil is provided only when the tappet is pushed upwardly or putwardly by the roller 98 riding upon the top of the cam 35. By means of this construction the quantity of oil supplied to the valve operating mechanism is definitely limited so that the flow of oil will not be suillcient to flood the valves and lead to difficulties in valve operation. Also, the oil is supplied to the valve operating mechanism only when all of the bearings of such mechanism are under load and consequently jammed tightly together so that the oil pressure through the valve operating mechapism is maintained and the device does not tend to materially lower the pressure in the engine lubricating system.

As stated above, each 01' the rocker boxes 28 has an oil tight construction and, in order to provide a closed oil tight system, each of the push rods 44 leading to the various rocker boxes is surrounded by a tubular member as indicated at I32. The upper end of each tubular ember I32 is connected to the respective ro er box by means of an oil tight connection .I84and the lower end is connected to the valve tappet guide 84 by means of a similar oil tight'con nection I36. This construction serves to provide an oil tight casing for the push rodsbetween the respective rocker arm boxes and the crankcase of the engine so that the entire valve operating mechanism .is enclosed in an oil tight casing and no substantial quantity of oil can be lost from the engine by forcing the oil to bers I38 may be rigid members cast or welded into the cylinder construction, but, in the form oi. the invention illustrated, both the tubular members I38 and I40 are formed in two sections, the adjoining ends of which are secured together by flexible rubber couplings as indicated I at m. As particularly illustrated in Fig. 4 the.

tubular members I38 and I40 together with the 75 rocker arm boxes 28 and 30 to which they are terminally secured, constitute a continuous oil channel around the outer circumference of the engine. At the bottom of the engine the opposite ends of this oil channel lead into the sides of .the sump as indicated at I44'and I46.

From the above construction, it will be observed that the oil which collects in the rocker arm boxes after passing through the bearings of the valve operating mechanisms will flow through the above described oil return channels back to the sump 50; the oil flowing from the top of the engine downwardly on both sides thereof and through the connections I44 and I46 into the sump.

Means are also provided for draining oil from those rocker arm boxes of the engine which are above a horizontal plane passing through the center of the engine through the tubular members I32 which surround the push rods 44. The tappet guides connected with the inner ends of the tubular members I82 above the aforesaid plane are each provided in their outer ends with an oil receiving slot or channel I48. In the construction illustrated, each of the valve tappets above the aforesaid plane is provided at its upper or outer end with a port I50 leading from the slot or channel I48 into the space between the tappet and the plug I I4. The enlarged end of each plug H4 is provided with a channel I52 leading from the space between-the plug and the tappet into the space at the lower end of the tappet into which the roller 88 projects so that oil returning from the upper rocker arm boxes through the upper tubular members I 32 -may flow into the slotted channel I48 and through the port I50 and channel I52 back to the interior or the engine from which it drains into the sump 48. Oil from both of the sumps 48 and 50 is returned by suitable scavenging pumps to a common oil reservoir from which it is again pumped into the pressure lubricating system of the engine.

While the present disclosure shows the oil from the upper rocker arm boxes returning through the interiors of the upper tappets, it is within the scope of the invention to provide suitable channels between the tappets and the tappet guldw connecting the annular channels or slots I48 with the interior of the engine so that the oIl from the upper rocker arm boxes may return to. the interior of the engine without flowing through the interiors of the tappets.

From the above description it will be observed that I have provided means for supplying a defi- 'nitely limited quantity of oil at predetermined intervals to the valve operating mechanisms of an internalcombustion engine and have provided adequate means for returning such oil to the lubrication system of the engine.

'While the accompanying drawings illustrate and specifically describe a particular mechanical construction in which the idea of the invention may be embodied, it is to be understood that the invention is not limited to the particular construction so illustrated and described, but that such changes in the size, shape and arrangement of parts'may be resorted to as come within the scope or the subjoined claims.

Having now described my invention 'so that others skilled in the art may clearly understand the same, what it is desired to secure by Letters Patent is as follows.

What is claimed is:

1. In an engine having an oiling system, a plurality of valves and valve actuating mechanisms,

means for supplying oil from said oiling system to said valve actuating mechanisms, and means for limiting the supply of oil to each valve actuating mechanism to those intervals during which the elements of said mechanism are under load.

2. In a. radial engine having an oiling system including a sump, a plurality of valves and valve actuating mechanisms, and means separately eni anisms, a. separate sump connected only with said closing each of said valve actuating mechanisms, means for supplying oil to said actuating mechanisms, and a separate dry sump below said oiling system included sump for receiving the oil valve enclosures havixm a sufficient capacity below the bottom cylinders of said radial engine to receive the 'oil'collected in all of said, mechanism enclosing means receiving the oil drained Irom said enclosing means, and means for maintaining said sump in a dry condition whenever the engine is operating.

4. In combination with an engine havinga crankcase, a plurality of. cylinders radially disposed around said crankcase, an oil sump on said crankcase between the two bottom cylinders,

valves on the outer end oi each cylinder, a valve of said valve operating mechanisms; means for forcing lubricant under pressure through all the elements of said valve operating mechanisms, a separate oil sump on said crankcase below said first mentioned oil sump and extending below the rocker arm boxes on the two bottom cylinders of said engine, and oil conduits interconnecting all of said rocker arm boxes and connecting said rocker arm boxes with said second mentioned oil sump.

5. In combination .with an engine crankcase, a plurality of cylinders radially disposed around said crankcase, an oil sump on said crankcase between the two bottom cylinders, valves on the outer end or each cylinder, a valve operating mechanism including a rocker arm. and

a. push rod between each valve and the crankcase,

having a a tubular member surrounding each push rod between the associated rocker arm box and the crankcase, a separate oil sump on said crankcase below said first mentioned oil sump, oil conduits interconnecting all of said rocker arm boxes and connecting said rocker arm boxes with said lower oil sump, and means for draining at least a portion of the oil from the rocker arm boxes above a horizontal plane including the axis of said engine through said tubular members and into said first mentioned oil sump.

6. In an engine having a crankcase, a plurality oi. valves remote from said crankcase, and a valve operating mechanism extending from each valve to said crankcase, each valve operating mechanism comprising a-rocker arm, a push rod and a valve tappet, each valve actuating mechanism having an oil passage therethrough from said tappet to said valve; means for supplying oil under pressure to said oil passages, and means associated with each tappet for limiting the supply of oil to those intervals during which the bearings of the respective valve operating mechanism are under load.

' guide and a port in said tappet registering with said first named port only when said tappet is i" a predetermined position for limiting the quantity of oil supplied to said valve operating mechanisms and for limiting such restrictedsupply of oil to those intervals during which the bearings of the respective valve operating mechanisms are under load.

8. In an engine having a crankcase, a plurality of valves remote from said crankcase, a valve opcrating cam insaid crankcase, and a valve operating mechanism'between each valve and said cam, said valve operating mechanisms each having an oil passage therethrough. and including a hollow valve tappet bearingon said cam and a tappet guide secured in said crankcase, means for supplying .oil under pressure to said tappet guides, a port in each tappet guide, a port in each tappet positioned to register with the port in the tappet guide when the tappet is on the high part oi! the cam, and a plug in each tappet having a channel therein connecting said tappet port with said oil passage.

ANDREW V. D. WILLGOOS.

n 1 s c L A l M E R 2,123,681.-A1|drew V. D. Willgoos, West Hartford, Conn. INTERNAL COMBUSTION ENonmRooxaa ABM Losarcs'rron.

Patent dated July 12, 1938. Disclaimer fi 1ed November '30, 1940, by the assignee, United Aircrafl Corporatwn, the inventor, approving and assenting. 4 Herebi disclaims claims'l, 6, 7, and 8 of said patent.

Gazette December 19', 1940.]

a. push rod between each valve and the crankcase,

ANDREW V. D. WILLGOOS.

Gazette December 19', 1940.]