US3087473A - Engine - Google Patents

Description

April 30, 1963 L. D. THoMPsoN r-:TAL 3,087,473

' ENGINE Filed Nov. 25, 1960 3 Sheets-Sheet 1 JNVENToRs fa/VEL Fra/wasn i' Een/557%. BAK/ms By ,804 Uyl/QL TTDQNEY April 30, 1963 L. D. THOMPSON ETAL 3,087,473

ENGINE 3 Sheets-Sheet 2 Filed NOV. 25, 1960 INVENToRs mA/EL 7/o/1/Pso/v i' BYEQA/Esr/J 734mm:

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ATTORNEY April 30, 1963 D. THOMPSON ETAL 3,087,473

ENGINE Filed Nov. 25, 1960 5 Sheets-Sheet 5 8.9 as; @o s@ 20 8? 6. 94 .92

1N VEN TORS mA/.ez /aMPJo/v United States Patent Office 3,087,473 ENGINE Lionel D. Thompson, Birmingham, and Ernest A. Tsakiris,

Detroit, Mich., assignors to Curtiss-Wright Corporation, Utica, Mich., a corporation of Delaware Filed Nov. 25, 1960, Ser. No. 71,538 1 Claim. (Cl. 12S-41.84)

This invention relates to internal combustion engines in general and more particularly to diesel engines of light weight and compact construction for marine and other uses.

There are numerous instances where engines of durable construction, high power output, low weight and small size are highly desirable. Such engines require more than the substitution of known light weight materials and the cumulative adoption of other engine practices.

An engine having a low weight ratio per horsepower requires a careful selection of materials and astute design analysis to enable the minimum use of the more expensive light weight materials and the elimination of nonfunctional parts and expensive machining without the sacrifice of durability. The relative location of component parts also contributes appreciably to the compactness of the engine and must be coordinated with the choice of materials and design requisite to preclude undue changes in the weight per horsepower ratio. The mere substitution of a lighter weight material, such as aluminum, for a heavier material is not always feasible without due consideration and the solution of new and different problems created by such use.

It is an object of this invention to teach the construction of a new and different internal combustion engine and one which has a higher power output for its size and weight than other comparable engines.

It is an object of this invention to disclose an engine having an aluminum cylinder block, individual cylinder heads, forged steel cylinder liners and means of construction and assembly not heretofore considered, for the purpose of insuring greater durability and a lower weight per horsepower rating.

Another object of this invention is to teach an aluminum block and wet liner construction free from the adverse effects of coolant cavitation.

Still another object of this invention is to teach a wet liner con-struction assuring better coolant flow about the combustion chamber space therewithin.

A further object of this invention is to disclose a cylinder head and liner retention means permissive of the use of materials having different rates of expansion without adverse effect.

An even further object of this invention is to disclose a `self-contained cylinder head arrangement for individual engine cylinders and including a replaceable precombustion chamber and burner orifice for turbulent air-fuel injection -within the `piston cylinder chambers.

These and other objects and ladvantages in the practice of this invention will be more apparent upon a study of the following description of an engine including the different and complementary aspects of such invention, and upon reference to the accompanying drawings.

In the drawings:

FIGURE 1 is a front end `view of an internal combustion engine having parts broken away and shown in cross section for better illustration of the invention.

FIGURE 2 is an enlarged cross sectioned view of the engine cylinder and wet liner arrangement with a cylinder head member secured thereover.

FIGURE 3 is an enlarged cross sectioned and minor exploded view of the coolant connec-tion to liner water jacket member.

FIGURE 4 is an enlarged and cross sectioned view of 3,087,473 Patented Apr. 30, 19.63`

the engine cylinder head arrangement inclusive of the aforementioned precombustion chamber and burner oritice.

'The engine y10, shown by the drawings, is a 12-.cylinder engine having two banks of `six cylinders each and arranged in a 60 V. The marine rating of the engine is a 900 brake horsepower at 2300 r.p.m. It has a 1704 cubic inch displacement providing a ratio of .53 horsepower per cubic inch. As adapted for marine installation, with installed accessories, the engine has the low weight ratio of 4.5 pounds per horsepower. The engine delivers 9.6 horsepower for every cubic foot of space occupied by the engine.

The engine 10 has an engine block 12 formed of cast aluminum and inclusive of both the cylinder block 14 and the crank case 16.

Individual cylinder liners 18 and cylinder heads 20 are provided within the cylinder bores in the cylinder block 14. Suitable intake and exhaust gas passages are provided through the cylinder block 14 to enable bolting the intake and exhaust manifolds, 22 and 24, directly to the block to preclude the necessity of removing such members in servicing any of the engine components or accessories.

The water manifold 26 and outlet header 28 are similarly arranged and connected to the cylinder block 14.

Accordingly, as will be appreciated as the description of en-gine 510 proceeds, general service and maintenance does not require the extensive work and down-time which Was formerly necessary. The problems of one engine cylinder may be remedied without disruption of other engine cylinders and in most instances without the removal of intake and exhaust combustion or coolant manifolds.

To further facilitate maintenance and service inspections, a removable cam shaft housing assembly 30 is provided over each bank of engine cylinders.

Each cam shaft housing assembly 30 is inclusive of two cam shafts 32 and 34 which are respectively operative of the intake and exhaust valves 36 and 38 provided within each of tbe cylinder heads 20. The cam shafts are installed in the aluminum cam shaft `housing from the ends thereof and are supported without the use of separate bearings. Hydraulic valve tappets 40 are provided within the cam shaft housings to compensate for clearance variation caused by thermal expansion of the valve gear and aluminum cylinder block.

Cam shaft housing 30 as `assembled with cam shafts and Valve litters, is removable as a unit for service Work on major components such as pistons, liners and heads. It is equally as readily reassembled on the engine cylinder block without problems of resetting the valve timing since the timing is not disturbed in the removal of the housing subassembly.

VThe crank sha-ft 42 is disposed within the crank case 16 and is a forged 7-bearing shaft having integral counterweights. Large diameter main journals and crank pins keep the bearing load relatively low and the overlap yis such as provides `a stili strong structure. The centerline of the crank shaft is located Well Within the crank case 16 and above the mating surface between t-he unit cast block and the oil pan. Is is mounted within forged aluminum main bearing caps 46 which are heldin place -by vertical studs 47 and lateral bolts 4'8. This arrangement affords a rigid box section and adds appreciable strength Vto the engine block construction.

Hand hole openings with suitable covers 49 are provided in the engine block to afford .access vto the `connecting rods 'on the Vcrank shaft 42 Without `removing the oil pan 50.

The oil pan 50 `is preferably of cast aluminum. For :dry sump installation, .a scavenging pump is provided in the -free end of the oil pan and it is ladapted to draw from -both ends of the oil pan and thereby permit the use of a shallow pan while retaining the ability to operate at high tilt angles in either direction. For wet sump operation, the oil pan and scavenging pump system is replaced with a deep oil pan sized and shaped to fit the application.

A steel tube 52 is cast in the cylinder block 14 at the bottom of the V to provide the main lubricating oil gallery. Drilled passages are suitably provided to carry the oil from this gallery to the various parts of the engine.

The engine pistons 54 are of cast aluminum and are cam ground so that they will more closely tit the cylinder barrell when both are under hot loads. The top of the piston is dished to provide a central dispersing cone. 56 which induces a controlled turbulence in the combustible gases entering the combustion space. The pistons are suitably recessed, as `at 57, for valve clearance. The connecting rods 58 include a 45 split cap to permit removal of the piston and rod assembly through the cylinder bore without disturbing the cylinder liners 18.

Referring now to FIGURE 2:

The cylinder liner arrangement is shown by FIGURE 2 to include steel forged cylinder liners 18 mounted in shouldered engagement, near their lower ends, with the liner receptive walls of the cylinder block 14. The liners are formed to provide an annular shoulder 6ft' near their lower end for the shouldered engagement mentioned.

Removable Water jackets 62 are provided about the cylinder liners 18 and serve to separate the collant fluid from the cylinder block to prevent cylinder block corrosion. The water jacket members 62 are press fitted on the liners 18 and have the further effect of stifening the liners and reducing liner vibration which is known to cause coolant cavitation and more rapid deterioration of walls exposed to collant fluids.

The cast jacket members 62 are formed to provide axially disposed internal ribs 64 near their upper ends.

"Ihe ribs 64 engage the liners 18 near their upper ends and are formed to provide coolant ow passages 66 therebetween. The flow passages 66 provide the exodus for coolant received within the space 68 between the liner and jacket members.

Aside from the liner stiffening afforded by the water jacket ribs 64, the liner is provided with an annular rib 69 intermediate the ends thereof.

Coolant is introduced to the water jacket space 68 about the cylinder liners 18 through an inlet coupling 79. A separate coupling member 70 is received Within a suitable access 72 provided through the cylinder block adjacent each cylinder bore. The coupling members are each received in threaded engagement with a Water jacket member 62 and have the other ends thereof exposed through the cylinder block. A compressible sealing ring 74 is provided on the exposed end of each coupling member and, when the Water manifold 26 is secured thereover, the sealing ring 74 is compressed to suitably seal off coolant flow between the cylinder walls and exterior of the jacket members. As will be appreciated, this arrangement readily accommodates any different rates of expansion between the cast jacket and aluminum cylinder walls without imposing any stress or strain on the coolant coupling union.

The cylinder heads 20 are of an alloy cast iron and are cylindrical in shape. Each head is inclusive of two intake and two exhaust valves, 36 and 38, with replaceable and heat resistant alloy valve seats and cast iron valve guides. Rotators are used on all valves and the exhaust valves are sodium cooled.

Each cylinder head is provided a precombustion chamber forming member 80. Such chamber forming member 80 is received in threaded engagement with the cylinder heads 20 and has the walls thereof exposed to coolant ow through the coolant chambers 82 and 84 and coolant passages 86 provided within the cylinder head member.

The precombustion chamber member 80 is receptive of the fuel injector conduit 88 in threaded engagement within one end thereof. The fuel injecting nozzle member (not shown) is disposed Within the nozzle space 89 immediately adjacent and for communication with the spherical precombustion chamber 90.

The spherical chamber 90 is formed within and between the `fuel conduit receptive part of the chamber forming member and the burner half 92 thereof. Multiple orifices 94 are provided through the burner part 92 of the precombustion chamber forming member and such orifices communicate together within a burner tip 96 to provide a high velocity jet orifice 98 communicating directly with the combustion space within the cylinder liner 18.

The spherical precombustion chamber 90' is Water cooled to protect the injection nozzle from excessive temperatures. At the same time, the communicating burner tip 96 is of a heat resistant alloy so that it may store heat to aid in the vaporization of the fuel by heating the air as it is forced into the precombustion chamber. The temperature is thus suitably increased in the precombustion chamber -to facilitate the initial ignition.

The initial ignition of fuel within the precombustion chamber 90 serves to confine the resultant high and erratic shock pressures within the spherical chamber and thereby greatly contributes toward permitting lighter weight engine cylinder and block construction and higher speed engine operation.

Following the atomized injection of fuel into the hot compressed air within the precombustion chamber 90, the atomized fuel and air begins to burn and raises the temperature and pressure until the mixture, including still unburned fuel, is forced out through the multiple orifices 94 and through the high velocity jet orifice 98. The high velocity jet is directed at the piston head where the dispersing cone 56 causes the jet to mushroom as the piston is forced down on the power stroke with a resulting turbulence that assures complete and clean burning of the fuelair mixture.

Each head and jacketed liner combination is held in place by a retainer ring 102 received over the cylinder head member. The retainer member is engaged by four long steel studs .1.00 which extend through suitable accesses HM provided in the cylinder block and are received in threaded engagement with the crankcase bearing webs 106. The long studs provide the needed elasticity to compensate for different rates of expansion as regards the steel cylinders and the aluminum block. Further, the bolts are engaged within the larger area of the crankcase bearing webs 106 rather than within the minimal wall space of the coolant passage areas of the cylinder block. This method of cylinder retention also permits the use of coolant flow passages 66 about the upper end of the liner and alignment of the coolant flow passages with the coolant chamber spaces in the cylinder head. Accordingly, maximum water cooling is provided near the top of the cylinder liner where maximum temperatures occur.

It is to be further appreciated that the expansion bolt retention of the cylinder liners 18 subjects the liners to an axial compression which affords further strengthening thereof and still further minimizes the chances of any coolant cavitation.

The advantageous structural features of the engine of this invention includes the unitary engine block construction cast from light weight aluminum material to include both the cylinder block 14 and crankcase 16. The use of the precombustion chamber 98 confines the erratic shock pressures of initial combustion within a small area and uniformly distributes the effects thereof so that a lighter weight engine block is practical. At the same time, the high centered position of the crankshaft 42 enables the use of vertical and lateral bolts 47 and 48 to retain the main bearing caps and provide a rigid box sectioned reinforcement of the engine block. Such bearing retention means also contributes to the satisfactory use of forged aluminum bearing caps in the engine block construction.

The engine of this invention is both compact in arrangement and readily serviceable for repairs and maintenance. The camshaft assembly 30 is a separate sub-assembly which may be removed and replaced without disrupting the valve timing setting and accordingly affords ready access to the major power components. Further, such camshaft housing is of aluminum and formed to minimize separate and expensive parts which might otherwise be required.

Intake and exhaust manifolds for both combustion gases and coolant iluid are engaged -directly to the engine block 12 and need not be disturbed for access to major power components. Where advisable the manifold connections to other parts, and through the engine block, are permissive of different rates of thermal expansion and accordingly permit the use of different and lighter weight materials.

The cylinder heads and jacketed liners 18 are securely retained within the engine block 12 by the same means of retention. This avoids the use of several and different retention means and in the use of the expansion bolts 100 affords a more satisfactory assembly.

The cylinder heads 20 may be separately removed for cylinder head or liner inspection without interference with other heads and liners and the valves, and precombustion chamber forming members 80 therein, may be removed, repaired, inspected and replaced Without diiculty.

With the cylinder heads 20 readily removable from the cylinder bores, the piston heads S4 and connecting rods 58 may be readily removed through the liners 18, due to the split-line of the rod caps, without undue difficulty. The disposition of the crankcase handnoles immediately adjacent the crankshaft 42 further facilitates such repairs.

The cylinder liners 1S are of superior quality in having the structural reinforcement of the water jackets 62, the bracing of the ribs 64 between the liner and cylinder walls (via the jacketing member) and the internal compressive strength imposed by the load of the retaining expansion bolts 100. All of this also contributes to the vibrational resistance of the liners and minimizes coolant cavitation possibilities.

The shoulder supported engagement of the cylinder liners 18 within the cylinder bores enables coolant passages 66 to be provided about the upper ends of the liners where high temperatures are most prevalent. It also enables coolant flow directly to the cylinder heads 20 and avoids hot pockets in the coolant system.

It will be appreciated that the engine of this invention makes use of the most suitable materials for certain specific purposes and coordinates the use of such materials to avoid diiculties due to different rates of thermal expansion, etc.

The lightweight cast aluminum engine block 12 is structurally reinforced within the crankcase 16 in cooperation with the main bearing retention means provided therein. In iserving a dual function such means are conservative of expensive materials, needless weight, and costly machining. The same applies for the camshaft and subasse-mbly 30.

The engine 1t? is provided with alloy cast iron cylinder heads 20, forged steel cylinder liners 18, and cast iron water jacket members 62. These members are retained within the .aluminum cylinder block 14 by bolts 100 which permit lrelative diiferences of thermal expansion therebetween. The hard wearing liners 1S assure long cylinder life and the water jacket members 62, aside from their principal function, serve to streng-then the liners Iand minimize coolant cavitation.

It will be appreciated that certain of the inventive concepts set forth herein are applicable to engines other than the preferred embodiment shown and described. Such of these concepts as Iare not specifically excluded by negative language within the claim which follows are to be considered as encompassed Within the claim having reference thereto.

We claim:

An internal combustion engine comprising an engine cylinder block including a cylinder bore and annulus of lesser diameter than the bore forming a shoulder therein; a cylinder liner in the bore including an annulus near the lower end of greater diameter than the diameter of said cylinder block annulus and forming a shoulder which rests on the `shoulder of lthe cylinder block annulus; a water jacket member about Said liner Within the bore providing a coolant flow passage next adj-acont said liner and separated from lthe cylinder block Wall forming the bore, the upper portion of the jacket member being in engagement with the wall of the bore `and said liner, and having annular ribs which both ystiften the liner and provide passageways in communication with ythe said coolant oW passage about the liner, a cylinder head in said bore over and in engagement with the cylinder liner, the cylinder head having coolant passages in communication with the passages provided by said annular ribs; and means holding said liner in compression between the cylinder head and said cylinder block shoulder for resistance to vibrational tremors.

References Sited in the iile of this patent UNITED STATES PATENTS 2,020,461 Dennison et al. Nov. 12, 1935 2,066,580 Severin et al Ian. 5, 1937 2,078,499 Ljundstrom Apr. 27, 1937 2,238,404 Spencer Apr. 15, 1941 2,619,078 Wirzky Nov. 25, 1952 2,677,356 Pielstick May 4, 1954 2,690,742 Kuepfer Oct. 5, 1954 FOREIGN PATENTS 464,699 Germany Aug. 25, 1928 853,841 Germany Oct. 27, 1952

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