US1903411A - Internal combustion engine - Google Patents

Description

A ril 4, 1933. L. M. WOOLSON ,9

INTERNAL COMBUSTION ENGINE I 4 Filed April 3, 1930 2 Sheets-Sheet .1

gww/ntoz I LJU EL M Nahum! April 4, L. M. WQOLSQN 1,903,411 INT11RNAL COMBIiSTION ENGINE I Filed April 3, 1930 2 Sheets-Sheet 2 LJUNEL M WHOLE-(7N Patented Apr. 4, 1933 UNITED STATES PATENT OFFICE LIONEL M. WOOLSON, OF DETROIT, MICHIGAN, ASSIGNOR TO I'ACKARD MOTOR CAR- COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN INTERNAL COMBUSTION ENGINE Application filed April 3, 1930. Serial No. 441,390.

This invention relates to internal combustion engines and more particularly to lubrieating systems therefor.

One of the objects of this invention is to provide a high compression internal combustion engine having a crank case with which a lubricating system is associated so that there are no weakening ducts formed there- 1n.

Another object of my invention is to provide a lubricating system for internal combustion engines in which the lubricant is conducted to a plurality of bearings through parts of the mechanism within the crank case with substantially no auxiliary conduits.

A further object of my invention is to provide an internal combustion engine having a removable diaphragm or reinforcing wall which serves as the distributer for directing oil to a plurality of bearings for the crank shaft and for mechanism operating valves and fuel injection devices.

Another object of my invention is to provide a simple form of lubricating system for subjecting the hub and connecting rod pins, of a connecting rod assembly for a radial type of engine, to a continuous stream of oil.

These and other objects of the invention will appear from the following description taken in connection with the drawings, which form a part of this specification, and in which:

Fig. 1 is a vertical medial section of a radial type of engine showing a lubricating: system associated therewith in a manner embodying my invention;

Fig. 2 is a fragmentary vertical sectional view of the upper portion of one of the cyl-, inders;

Fig. 3 is a partial sectional view of a pump mechanism utilized in the system;

Fig. 4 is a fragmentary end elevation of 4 the connecting rod assembly partially in section showing the lubricating system there for Fig. 5 is a diagrammatic view illustrating the lubricant circulating system.

Referring now to the drawings by characters of reference, 10 represents a unitary bar'- rel type of casing the open end of which Is open for the accommodation of an inertia starter (not shown) which is preferably bolted thereto so that such opening is normally covered. The crank case described is formed preferably of an aluminum alloy. A plurality of radially disposed cylinders 12 extend through the front end of the peripheral wall of the casing 10 and are provided with flanges 13 which bear against such wall and are secured thereto by a pair of compres- SlOIl rings or bands 14. The cylinders are each preferably formed with an integral head 15 and upon each of such heads is bolted an auxiliary head 16.

In order to permit the pistons 17 to draw in air charges during their suction strokes,

I provide each cylinder'with a single passage 18 which extends through the integral head 15 and auxiliary head 16, and I also utilize such passages as the exhaust outlet.

A valve 19 is associated with the inner end of each of such passages and is normally held closed by a plurality of springs 20, it being proposed to keep the valves closed during the compression and power strokes of the pistons and open duringthe air intake and the exhaust strokes of the pistons.

The engine illustrated is preferably of the compression-ignition or Diesel type which is of such light weight that it can be utilized to I propel an airship, its weight being less than two and a half pounds'per H. P., developed. With this type of engine, therefore, I propose to inject liquid fuel charges into the air charges while being compressed within the cylinders, and associated with each cylinder is anozzle21 having a pump mechanism indicated generally at 22 associated therewith, the nozzles extending through the cylinder walls so that the fuel can be forced by the pumps directly into the interior of the cylinders. The valves 19 are each mechani cally actuated by a rock lever 23, there being a push rod 24 parallel with each cylinder for actuating each rock lever and a push rod 25 associated with each pump mechanism arranged in a parallel relation with the valve push rod of each same cylinder,

The space formed by the casing 10 and the rear cover wall 11 is divided interiorly by a casing reinforcing diaphragm 26 whichis detachably secured to bosses projecting from the peripheral wall of the casing section 10, and this diaphragm wall is arranged substantially in the plane of the rear retaining band 14. It will thus be seen that the diaphragm 26 divides the interior of the crank case into two compartments 27 and 28, the connecting rod assembly being arranged within the compartment 27, and mechanisms for actuating the push rods 24 and 25 are arranged within the compartment 28 and driven from the crank shaft. The crank shaft illustrated is of the single throw type and is arranged to extend axially of the crank case, the forward bearing portion 29 of the crank shaft being supported by a ball bearing 30 at its forward end and by a roller bearing 31 at its inner end, such bearings being carried by the forward hub portion 32 of the crank case section 10. The rear bearing section 33' of the crank shaft is detachably clamped to the crank pin 34 by the bolt 35 and there are crank cheeks 36 to which counterweights 37 are pivotally attached by the pins 37'.

A connecting rod assembly is carried by the crank shaft pin 34 and-includes a master rod 38 which is formed with a hub 39 through which the crank shaft pin extends, there be-.

- ing a two-part spaced bushing 40 between the hub and the crank shaft pin. Arranged in a circular relation around the hub 39 and carried thereby are a plurality of pins 41 upon which the connecting rods 42 are pivotally mounted. It will be understood that the masterrod and connecting rods extend to and are pivotally associated with piston pins 43.

As heretofore stated, the compartment 28 houses the driving mechanism for the push rods which actuate the valves and the pump mechanisms, such push rods 24 and 25 projecting into the compartment. A ring memher 44 encircling the crank shaft portion 3.3 within the compartment 28, maintains the races of the roller bearing 45 in axial rela tion with the diaphragm and crank shaft, serves as a mounting for the hub 46 of the cam member 47 and provides a circular recess 48, the purpose of which will be herein.-

after described. This ring member 44 is held axially by the retaining member 49 which is mounted in a groove in a crank shaft extension 50. The extension 50 is keyed to the crank shaft portion 33 and is secured axially by a hollow pin 51, such crank shaft extension having jaws 52 at the rear end thereof for engagement with a starter. The crank shaft extension is formed with a gear 53 which meshes with a gear structure 54 which has a shaft portion 55 supported by a bearing 56 carried by the end wall 11 of the casing. The gear structure 54 is formed with two gears of different diameters, one of which meshes with the gear 53 and the other of which meshes with the internal teeth 57 formed on the cam member 47, such geared connection between the cam and the crank shaft rotating the cam at one-eighth crank shaft speed during engine operation.

The forward peripheral portion of the cam structure is formed with spaced lobes 58 while the rear peripheral portion is provided with spaced lobes 59. The lobes 58 are arranged in a plane with the fuel plunger push rod operating mechanisms while the lobes 59 are arranged in a plane with the valve push rod operating mechanisms. A plurality of 1 each engage with a rod 65 for actuating the valve push rods 24 in a direction to open the valves when actuated by the lobes 59. It will be understood that the fuel injection operating mechanism is arranged so that it can be adjusted to vary the quantity of charges injected. A conventional form of breather 66 is associatedwith the upperportion of the casing wall 11, thus establishing communication between the compartment 28 and atmosphere.

I will now describe an embodiment of my invention associated with an engine of the character above set forth. In order to assist in providing a lightweight engine of the character described, I propose to utilize some of the elements of the engine proper for conveying lubricating oil in its travel through the circuits interiorly of the crank case and such an arrangement is made without passages or ducts-in the main engine crank case which would serve to weaken the same when subjected to the explosion and compression loads of a compression-ignition type of engine, and especially when such casings are formed with wall thickness substantially the same as that of gas engines utilized for aeroplane engines operating under a compression pressure of approximately one hundred twenty-five pounds per square inch instead of five hundred pounds per square inch as in the type of engine illustrated.

The diaphragm 26 is provided with a plurality of passages 67 which extend radially from a circular groove 68' formed in the inner face or hub portion. One of the passages 67. and preferably the uppermost, is several times the diameter of the others so that it has a capacity capable of distributing the quantity of oil which is circulated to the plurality of bearings within the crank case.

The hollow rock lever shafts 60, as before described, are pressed into openings formed in the diaphragm, and a ,port 68 leads through 5 such fitted ends of the shafts and establishes communication between the interior thereof and the passages 67 in the diaphragm. The uppermost rock lever shaft is formed so that its capacity will be suflicient for conducting l lubricant into the associated distributing passage 67, and at the outer end of this uppermost rock lever shaft, there is an apertured plug 69 which is carried within the hollow boss 61 with which the inlet conduit 70 opens.

l The rock lever shafts are provided with two series of apertures 71 arranged in alignment with the hubs of the rock levers mounted thereon. It will be seen that lubricant enters the uppermost rock lever shaft, because of its communication with the inlet conduit 7 O, and

from such shaft it flows through the port 68,

into the uppermost radial passage 67, then around the circular recess 68' and into the other radial passages 67 which communicate 2 with such recess, the other hollow rock lever shafts each having inlet ports 72 communicating with a radial passage. In this man- .ner. oil is fed to the bearing surface hubs of the rock levers 62 and 63.

A portion of the oil entering the uppermost of the radial passages 67 passes to the interior of the hollow crank shaft section 33 in a manner which I will now describe. The uppermost of the passages 67 communicates 3 with an outlet port 73 with which there is associated a cap member 74 which is secured to the diaphragm by the bolts 75. A ring member 76 encircles the hub of the cam 47 and is provided with an inner circular recess 77,

such ring having a hollow boss 78 which communicates with the cap member 74 through a swivel union or conduit 79. such conduit being mounted in this manner to permit a slight mo ement of the ring member without disturhing the position of the cap member 74 which otherwise might cause leakage or breakage thereof. The hub 46 is provided with an inner circular groove 80 from which a plurality of ports 81 communicate with the recess 77 in the ring member. and the oil flows through the ring member. the cam hub and ports 82 in the member 44. into the recess 48 formed by such member 44 and the hollow crank shaft section 33. A plurality of ports 83 connect the recess 48 with the interior of the shaft section 33. i

It will be seen that the. lubricant flows through the outlet port 73 in the diaphragm, through the cap member 74. the conduit 79,

the ring member 7 6, the cam hub and the ring member 44 into the crank shaft. During such travel of the lubricant, the engaging surfaces between the rotated cam and the relatively stationary ring member 76 will be adequately lubricated, and likewise, the bearing surfaces between the cam hub and the relatively stationary ring member 44, as well as the engaging surfaces of the ring member 44 and Any excess Oll passing the crank shaft. through such bearings and through the hollow rock lever shaft 60 will eventually drain or fall into the bottom of the compartment 28. A

From the hollow section 33 of the crank shaft, lubricating oil is distributed to the engine elements within the compartment 27 which require lubrication. A passage 84 leads to the hollow crank pin 34 and a tube 85 extends through the front crank cheek for conducting oil from the hollow crank pin to the bearing portion of the front counterweight 37, while a tube 86 extends through the rear crank cheek 36 and conducts lubricating oil from the hollow crank section 33 to the bearing surface of the rear counterweight pin 37, there being a distributing passage 87 associated with such tubes for conducting lubricant to the bearing surfaces at each end of the counterweight structures.

As heretofore described the bearing sections 40 between the crank pin and the master rod hub are spaced, and connected with the circular space therebetween is a port 88 which leads from the hollow crank pin and serves to distribute oil therefrom to the master rod bearingand the connecting rod bearings. A plurality of axially extending grooves 89 are formed in the master rod hub and a pair of radial passages 90 extend from each of such grooves to the hollow interior of adjacent connecting rod pins 41 and a port 91 leads from each hollow connecting rod pin to the associated hub of the connecting rods 42. It will be seen that the entire bearing portions of the connecting rod assembly will thus be continuously lubricated from the hollow interior of the crank shaft pin.

Some of the oil forced through the various bearings arranged within the compartment 27, so far described, will be in a suspended condition during operation of the engine and some of such oil will fall into the port 92 in the casing 10 leading to the bearing 31. It will be understood that oil so entering the hearing 31 will move along the shaft section 29 to the bearing 30. Excess oil within the hub 32 of the crank case can drain through the aperture 93 into the compartment 27. It will also be seen that the oil in suspension within the compartment 27 will serve to luhricate the cylinders 12.

Any oil falling by gravity to the bottom of the compartment 27 will drain through the outlet opening 94, in the lowermost portion of the diaphragm 26, into the bottom of the compartment 28 which serves as a sump. The lubricating system of the engine illustrated, is of the well known dry sump type. Oil drains from some of the shafts 60 through ports 111 in the associated rock levers 62 to lubricate the lobes 58 on the cam structure.

The mouth 96 of the outlet conduit 95 is arrangedadjacent the bottom of the sump in acompartment 28, and suction created by a scavenging ump, represented generally at A, serves to raw lubricant from the crank case through' the conduit 95 and move it through the conduits 97 and 99 leading respectively to a cooler 98 and from the cooler to a tank or reservoir 100. A pressure pump, illustrated generally at B, is connected with the tank 100 by a conduit 101 and lubricant is moved by the pressure pump through the conduit to the distributing system within the engine casing." The pumps A and B are mounted in a casing structure hereinafter described, and in the event that there is excessive pressure in the system, I provide a passage 102 in the casing through which oil is shunted from the conduit 70 directly to the return conduit 97, this passage being controlled by a spring-pressed valve 103.

1 In engines of the compression-ignition or Diesel type, the high compression employed gives a large amount of heat to the oil circulating in the lubricating system largely by reason of the high piston temperatures. Coolers have been employed in lubricating systems for lowering the temperature of oil after leaving the engine in its cyclic circulation, andwhen an engine of the character described is used as the power plant of an aeroplane, I have found that under average high temperature conditions a moderate size cooler-is suflicient to maintain the oil below a critical temperature. However, on a hot day, with the engine developing its maximum power for continuous periods, I find that the oil temperatures with a moderate size cooler are excessive. In an efi'ort to improve this temperature condition without having recourse to an excessively large oil cooler, I find that in circulating the hot oil through the cooler at various rates with an increase in the rate of oil circulation, the efliciency of the moderately-sized cooler rose rapidly until a peak was reached. For example, in circulating one and one-half gallons of oil per minute through such cooler, the oil temperature was reduced sixty-three degrees whereas, when the rate of circulation was increased to sixand nine-tenths gallons per minute, the oil temperature was reduced twenty-nine degrees. Multiplying the flow by the temperature difference gives figures of merit, respectively-of 94.5 and 200' indicating that the oil cooler under such conditions is practically twice as efficient with the high rate of flow.

In the engine illustrated, the lubricating system is preferably arranged so that approximately two gallons of oil flows through the engine per minute and it is not desirable to increase this flow through the bearings nor is it desirable to increase the capacity of the oil pressure pump B beyond that required for the engine since the scavenging pump A must at all times have a twenty-five to fifty per cent excess capacity over the pressure pump, and if the pressure pump bypasses a considerable amount of oil back through the cooler without going through the scavenging pump, then the large scavenging pump will pump considerable air into the system resulting in foaming in the oil tank which is a very undesirable condition. In order to secure advantage of the full efiiciency of the cooler without increasing its size and without raising the rate of oil flow through the engine, I provide means for circulating a quantity of. oil directly from the oil tank through the cooler, preferably utilizing the inlet conduit 10'1 leading to the pressure pump and the return scavenging conduit 97. A circulating pump C is provided for this purpose and communicates with the inlet conduit 101 by means of a passage 104 and communicates with the return conduit 97 leading from the scavenging pump A by means of the passage 105. The pumps A, B and C are preferably of the gear type and are arranged in the casing 108 having partitions 109 and 110 forming separated chambers for the pumps. The pumps are all driven by a shaft 106 through means of a gear 107 which meshes with the gear structure 54,- previously described.

It will be seen that the system comprises circulating oil under pressure in a closed circuit from the reservoir or tank to the engine parts to be lubricated, that the'draining oil is then collected and moved by suction from the engine and returned by pressure through a cooler to the tank. Further,

-oil from the tank is moved by pressure directly to oil returning from the engine to.

increase the volume of oil passing through the cooler, thus utilizing a given cooler surface to maintain the oil at an efficient temperature when exposed to extreme heat conditions.

While I have herein described in some detail a specific embodiment of my invention,

which I deem to be new and advantageous and may specifically claim, I do not desire it to be understood that my invention is lim-' ited to the exact details of the construction, as it will be apparentthat changes may be made therein without departing from the spirit or scope of my invention.

-What I claim is:

1. In an internal combustion engine, a crank case, a diaphragm in the'crank case having passages therein each communicating with'engine parts to be lubricated and serving as a lubricant distributer, pressure means for forcing a continuous stream of oil through the diaphragm passage to the parts to be lubricated during engine operation, and means for removing collected oil draining from the lubricated engine parts.

2. In an internal combustion engine of the radial type, a closed'crank case, a diaphragm dividing the crank case into compartments, said diaphragm being provided with a circular groove and a plurality of passages radiating from the circular groove for directing lubricating oil to a plurality of engine parts adjacent the diaphragm,ipressure means for forcing a continuous stream of oil through the diaphragm groove and passages to the parts to be lubricated during engine operation, and means for removing oil collecting in the crank case.

3. In a compression-ignition internal combustion engine, an aluminum alloy crank case formed with thin walls and maintained under compression greater than the maximum load imposed thereupon, said crank case being devoid of ducts, a reinforcing diaphragm within the crank case having passages formed therein for distributing oil to a plurality of moving engine parts within the crank case, means for moving a stream of oil through the passages in the diaphragm, and means for removing excess oil collecting in the crank case.

4. In an internal combustion engine, a crank case, a diaphragm in the crank case having oil distributing passages formed therein, ported hollow shafts carried by the diaphragm and in communication with the passages in the daphragm, rock levers carried by the shafts, means for forcing a stream of oil through the diaphragm passages and hollow shafts to the bearing portion of the rock levers, and means for recirculating oil passing through the hollow shafts.

5. In an internal combustion engine, a crank case having an oil feeding system leading through an end wall thereof, a diaphragm in the crank case having an oil distributing passage formed therein, conduit means connecting the system leading through the crank case wall with the passage in the diaphragm, a hollow crank shaft in the crank case, means establishing communication between the passage in the diaphragm and the interior of the crank shaft, said hollow crank shaft being arranged to distribute oil to a plurality of engine bearings, pressure means forcing oil through the diaphragm and crank shaft to the bearings during engine operation, and means for removing oil draining from the hearings to the exterior of the casing.

6. In an internal combustion engine, a crank case, a diaphragm in the crank case having an oil distributing passage therein, means supplying oil under pressure to the passage in the diaphragm, a hollow crank shaft in the crank case extending through the diaphragm, a cam member surrounding the crank shaft and rotatable relative thereto, means establishing a connection between the interior of the crank shaft and the diaphragm passage through the cam member, said means also communicating with the cam hulxmeans for directing oil from the hollow crank shaft to engine bearings, and means for withdrawing excess oil from the crank case. V

7. In an internal combustion engine, a hollow crank shaft pin having a passage extending radially therethrough, a master rod hub through which the crank pin extends, spaced bearings intermediate the hub and crank pins, the space between the bearings communicating with the radial passage in the crank pin, one of said bearings having a plurality of axially extending peripheral grooves leading from the inner end, connecting rod pins in the hub, said grooved hearing and hub having radially extending passages therein leading to the pins, every two 'ad acent passages radiating from one of the axially extending grooves in the bearing, and means for supplying oil under pressure to the interior of the crank pin when the engine is operating.

8. In an internal combustion engine, 'a crank case, a hollow crank shaft in the crank case, a pressure oil system communicating with the interior of the hollow crank shaft,

counterweights pivotally carried by the crank shaft, said crank shaft having passages leading from the hollow interior to the counterweight bearings, and means for removing oil from the crank case draining from the bearings.

9. In an internal combustion engine, a crank case, a diaphragm in the crank case having a manifold passage therein and a plurality of distributer passages leading from the manifold each communicating with engine parts to be lubricated, means for feeding a continuous stream of oil to the manifold and through the distributer passages in the diaphragm during engine operation, and means for removing collected oil drained from the lubricated parts.

10. In an internal combustion engine, a hollow crank shaft having counterweights pivotally carried by the crank arms, passages in the crank shaft leading from the hollow inlever shaft extendin between an outer wall of the crank case an the diaphragm in communication with the manifold therein, and a pressure lubricating system connected with the hollow shaft.

In testimony. whereof I aflix my signature.

LIONEL M. WOOLSON.

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