US2224900A

US2224900A - Outboard motor

Info

Publication number: US2224900A
Application number: US212078A
Authority: US
Inventors: Warren C Conover
Original assignee: Outboard Marine & Manufacturing Co
Current assignee: Outboard Marine & Manufacturing Co
Priority date: 1938-06-06
Filing date: 1938-06-06
Publication date: 1940-12-17
Anticipated expiration: 1957-12-17

Description

Dec- 17, 1940. w. c. coNovER 2,224,900

OUTBOARD MOTOR Filed June 6, 1938 4 Sheets-Sheet l j" J y 95 'WARREN C. QON OVER ATTOR N EYS 17, 1940. w, Q CQNOVER 2,224,900

OUTBOARD MOTOR Filed June 6, 1958 4 Sheets-Sheet 2 9 f 9 r4 L. I g f/ i 27 --/`/5= V /56 ,75 Q /57 K INVENToR 1 WARREN. C. CoNouEfa l BY ma wrm ATTORNEYS Dec. 17, 1940. w. c. coNovER 2,224,900

OUTBOARD MOTOR Filed June 6, 1938 4 Sheets-Sheet 5 INVENTR WARREN C. CoNQvea,

ATTORN EYS Dec. 17, 1940. w. c. coNovER OUTBOARD MOTOR F'iled June 6, 1938 4 Sheets-Sheet 4 lllllflllllllllla,

INVENTOR WARREN C. CON QVEQ BY mmfm ATTORNEYS Patented Dec. 17, 1940 UNITED STATES PATENT OFFICE OUTBOABD MOTOR Application June 6, 1938, Serial No. 212,078

Claims.

This invention relates to improvements in outboard motors.

An important object of the invention is to provide a novel and improved organization of pas- 5 sages for the flow of uids through the device. More particularly stated, it is an object of the invention to provide an outboard motor organization freely rotatable on its swivel bearing for steering and yet provided with an under water exhaust. This involves as an objective the delivery of exhaust gases through the shaft housing in immediate proximity to the crank case, and this in turn makes it desirable, and it is a further objective of the present invention, to provide means for cooling the gases and particularly for keeping the engine crank case cool under circumstances which, but for a very novel organization of the cooling system, might in this particular arrangement of the exhaust gas passages, result in overheating the crank case and the lubricant and combustible mixture therein contained.

Also involved in the objects of the invention is the provision of a novel engine structure closely related to the problems aforesaid in that I desire to provide special crank case, engine bearing, cooling jacket, exhaust manifold, intake passage, water connection, shroud, and other features of facilitating the flow of gases and water in an outboard motor structure organized to provide an underwater exhaust and yet to permit of free swiveling movement for steering and reverse.

Other objects of the invention relate to a novel and improved construction of the drive shaft casing and supplemental shaft housing, likewise specically developed for the `aforesaid purposes. .Still other objects of the invention relate to a novel improved construction of lower unit and the water circulating pump and passages therein contained, as Well as to-a specifically improved driving connection to the propeller shaft therein. Other objects will appear in more detail fro the following disclosure.

In the drawings: Figure 1 is a side elevation of a complete outboard motor embodying the invention.

Figure 2 is an enlarged detail view of the upper part of the motor in vertical fore and aft section. Figure 3 is a view of the lower part of the motor on an enlarged scale in axial fore and aft section.

Figure 4 is a fragmentary detail view taken in section generally on the line 4-4 of Figure 2, the so-called shaft housing flange being exposed in plan and partially broken away to show the underlying structure in section.

Figure 5 is a detail view taken in section on the line 5-5 of Figure 4.

Figure 6 is a view taken in section on the line 6-6 of Figure 4r Figure 7 is a view taken in section on the line 1-1 of Figure 2.

Figure 8 is a view taken in horizontal section through the upper part of the fuel tank and the cylinder-enclosing shroud, portions of the Iiywheel being broken away to show the underlying engine structure in plan.

Figure 9 is a detail view taken in section on the line 9--9 of Figure 2.

Figure 10 is a detail view in side elevation of the adjustable thrust bushing member shown in Figure 9.

Figures 11, 12, 13, 14, 15 and 16 are views of the engine and its relation to the drive shaft housing and carburetor with particular reference to the fluid passages. Figure 11 isa view'taken in section transversely through the engine on the line indicated at lI-II in Figure 12. Figure 12 shows .the engine in side elevation with parts broken away to expose the interior passages. Figure 13 is a view taken in section on the line I3-I3 of Figure 14. Figure 14 is a viewtaken in section on the line Il-Il of Figure 13. Figure 15 is a view taken in section on the line |5-I5 of Figure 14. Figure 16 is a view in perspective of the separately constructed plate which provides an expansion chamber and inlet manifold for the engine.

Like parts are identiiied by the same reference characters throughout the several views.

The outboard motor is made to swivel as a unit for steering and reversing in the swivel bearing 20 which, for purposes of illustration, is carried by a bracket arm 2| pivoted at 22 to a more or less conventional transom bracket 23 having spaced arms 24 provided with arcuate slots in which the semi-tubular thrust bearing 25 is adjustable. This bearing is preferably provided with a transverse boss 26 having guide anges 21 fitted to the slots of the respective arms 24 so that in all positions of adjustment of the thrust bearing 25 longitudinally of the arms the bearing will be maintained at the proper angle to receive the drive shaft housing hereinafter to be described.`

A clamping bolt 28 extending through the bushing and having its head and wing nut engaged with arms 2l, maintains the bushing in adjustment to determine the initial upright position of the outboard motor to which it will return under thrust of its propeller when tilted about the pintle 22, as in encountering a shoal or other obstacle. 5 That portion of the outboard motor structure whichis swivelled in bearing is known as the shaft housing. It preferably constitutes a support upon which the power head and lower unit are unitarily assembled. In this instance the shaft housing preferably comprises a composite structure including a casting 30, an outer tube 3|, and an inner casing 32. The casting 20 connects the tubes 3l and 32 in the desired assembly, provides the necessary passages for water and exhaust gas hereinafter to be described, serves as a* base to which the tiller is connected, and provides a mounting flange upon which the entire power head is carried.

It will be noted that the outer sleeve 3l is pressed into the sleeve-like lower nut of the casting 30. The outer tube and casting together provide a passage 33 for exhaust gases which has an opening laterally at 34 to receive such gases from the power head. Above this opening the inner casing 32 is anchored in a bushing 35, the object of this inner tube being to exclude gases and water from contact with the drive shaft 35, and from the crank case bearings.

The supply water pipe 31 terminates in cast- 80 ing 30, where it is held by an expander 38 as shown in Fig. 5 for delivery of Water through the mountingdlange of casting 30 toward the power head.

The return water is delivered from the power head through pipe 42 into the short discharge passage 43 formed within the casting 35 and arranged t0 discharge the partially heated water directly into the exhaust stream.

Supported on the flange 40 (Figs. 2, 4, 5 and 4o 12) is the entire power head. This comprises an engine self-contained even to the inclusion of a fuel tank and, preferably, a ywheel magneto. Bolts 44 connecting to the crank case 45,

and bolt 45 connecting to the fuel tank 41, and 45 bolts 48 connecting to the exhaust manifold portion 43 of the cylinder casting 50, serve to maintain the power head in assembly on the shaft housing structure.

As indicated in Figs. 7, 12 and 14, the crank case 45 comprises two parts 45a and 45b united on the transverse axial center line. The bushings in which the crank shaft 5l rotates are preferably made as shown in Fig. 7 to comprise two

semi-tubular bushing sectors

52 and 53, each of 55 which has an arcuate extent somewhat less than 180 degrees, and each of these sectors being cast into the metal of its associated component part of the crank case. By casting these bushing sectors into the metal of the crank case a portion of the crank case metal flows about the end of each bushing sector, thereby anchoring the sector securely against rotative displacement in the casting. I'he bushing 54 of the connecting rod bearings of connecting rods 55 may be similarly cast into the component parts of the bearings.

The upper end of crank shaft 5l may carry a conventional flywheel magneto 55, and its lower end may be provided with a squared socket to receive the correspondingly formed upper end of the drive shaft 35, this arrangement also being conventional.

The crank case 45 preferably has a central bearing at 58 dividing the crank case into two separate chambers wherein the crank shaft has 5 diametrically offset cranks to which -the connecting rods 55 connect the pistons 53 for movement in the cylinders 50. The cylinders in this particular style of motor are superimposed and the design is a conventional one in which the ring alternates so that when the engine is operated on the two cycle principle the two cylinders yield two power impulses for each crank shaft revolution.

The cylinders 50 comprise an integral part of the cylinder casting 50. This casting also includes a jacket 5| and the means 49 which provides a portion of the exhaust gas passage. The stern side of the crank case and the stern side of the underlying shaft housing casting 30 are machined to a common face at 52 abutted by the complementary face of the cylinder casting.

A series of webs connect the cylinders 50 with the jacket 5I in the cylinder casting 50. Some of these webs partition of! the gas passages and will be described later. At this time attention is invited to the web 55 which extends circumferentially about both cylinders as shown in Fig. 2 and Fig. 15 to divide the water jacket space into the base compartment 55 and the head compartment 51. A small hole through this partition web at 58 is intended solely for drainage and does not by-pass any substantial volume of water during engine operation.

The base portion 53 of the crank case has a downwardly opening annular channel at 10 registering with the hole 1I which extends through the supporting flange 40 of the shaft housing adjacent the terminus of the water supply pipe 31 (Figs. 2, 4 and 5). The channel 10 is not only a water conduit but, of itself, it provides a cooling jacket handling water fresh from the lake in which the outboard motor operates and thereby providing a very effective chilling medium between the crank case and that portion of the lower unit casting 30 into which the hot exhaust gases are delivered.

An opening at 13 in the rear face 52 of the crank case registers with an opening 14 in the cylinder casting 55 to afford communication between the channel 10 and the base jacket compartment 55. It is desirable that the base Jacket chamber 55 should initially be cooled by the arriving water first, for the protection of the crank case from engine heat, and secondly, because the heat thus initially imparted to the water will enable the combustion chamber desirably to operate at higher temperatures than would otherwise be the case.

Any leakage from channel 1li toward the drive shaft 35 is received in a well 12 (Fig. 6) which is drained by a duct 130 to the outside of casting 30. The upper end of the inner driveshaft casing 32 is socketed in a plug 140 having an upstanding annular ange about the drive shaft 35 to serve as a dam for keeping the water from falling along the drive shaft.

From the top of the base jacket compartment 55 I provide an external water pipe 15 (Fig. 15) which leads downwardly and at a rearward inclination to enter the bottom of the jacket compartment 51 by which the heads of the cylinders are enclosed. Thus the water partially heated in the Jacket chamber 55 rising naturally toward the top of that chamber, is removed from the top of base chamber 55 and enters at the bottom of chamber 51 through which the water again rises toward the discharge pipe 42 opening from the -top of compartment 51 and returning to deliver the overflow water into the exhaust gases through the duct` 48 cast in the shaft housing casting 38 as previously described.

The drain opening 86 acts as a partial by-pass for the water supplied to chamber 88. An additional portion of the water supplied to chamber 66 is by-passed through the opening 11 (Figs. 2 and 15) to the jacket compartment 18 which intervenes between the transfer ports 18 and finally opens into the main head Jacket compartment 81 after such transfer ports terminate.

Unlike other motors of this type, the intake and exhaust passages are provided at the same side of the cylinder block and are cast in the same piece. An expansion chamber is preferably provided partially within this added piece and partially within a cavity formed in the side of the cylinder block, the exhaust manifold being preferably formed in the cylinder block itself for reasons hereinafter to be stated.

'I'he casting 88, which is shown separately in perspectivein Fig. 16, is bolted to the` cylinder block to provide in conjunction therewith a jacketed expansion chamber 8| and an inlet manifold 82 having a mounting flange at 83 for a carburetor 84. The manifold is subdivided by partition 85 to provide passages leading to the

intake ports

86 and 81 of the respective cylinders. This being a three port engine, the ports 88 and 81 are controlled by the skirts of the respective pistons 59 (Fig. 14) to'admit the incoming charge to the crank case when the piston is at the top of its compression stroke. During the expansion stroke of the piston the charge is compressed in the crank caseand finally delivered to the cylinder through the appropriate transfer port 18 which, on entering the cylinder, is preferably subdivided by bridges in the usual manner as shown in Fig. l1. At the time of transfer the gases burned in the cylinder are discharged through the exhaust ports 98 into the common expansion chamber 8| (Figs. l1, 12 and 14).

As shown in these views, the expansion chamber is partially formed within the cylinder casting and partially within the casting 88, the latter being provided with a water jacket at 9| which communicates with the cylinder jacket space 61 through ports 92 at the bottom and 93 at the top of the horizontal cylinder casting (Fig. 12). As clearly shown in the drawings, the cylinder jacket chamber 61 surrounds the outer ends of the respective cylinders and also cools the expansion chamber 8|, the expansion chamber being completely surrounded with water jacketing except adjacent a pipe of the intake manifold.

The exhaust manifold 95 is not formed within the expansion chamber casting 88, but is formed as a part of the cylinder block, extending around beneath the lower cylinder and opening into the shaft housing through the exhaust port 34 as previously described. As above noted, a single machined surface at 52 may be continuous across the cylinder casting and the exhaust manifold built therein and in such case may co-act with a single complementary planiform machined surface on the crank case and lower unit so that gasket means applied between these respective surfaces will seal the crank cases in communication with their respective cylinders and will seal the water supply connection and the exhaust gas connection. In practice there are some advantages in having these surfaces only approximately in the same plane, one of the surfaces at one side or the other being offset perhaps .020 inch, whereby a gasket of slightly increased thickness may be used between the cylinder and the lower unit.

'I'he fuel tank 41 extends arcuately about the crank case, enclosing the forward side thereof and supported centrally on the tiller handle bracket 48. Pivoted to the fuel tank by means of links 81, one of which is shown in F18. -.1, is a shroud 88 enclosing the cylinder portion of the engine and particularly the spark plugs 88. Access to the spark plugs is readily had by drol!- pig the shroud to the position shown in dotted lines in Fig. 1 upon release of the bolt |88 which normally holds the shroud securely to the boss provided at |8| in the cylinder casting (Fig. 2). An opening at |82 in the shroud and an adjoining rounded flange |83 provide a hand hold for facilitating the lifting of the motor in applying it to a boat or removing it therefrom, or for carrying purposes.

`I'he flywheel at 56 may be provided with starting mechanism which, except for the handle |85, is not illustrated, being contained within the cover |86 and having no direct-bearing with this invention except insofar as the cover completes the substantial enclosure of the engine which is constituted within the power head of this device.

At the lower unit the outer and inner sleeves 3| and 32 constituting the shaft housing are separately anchored. The lower unit casting I |8 is provided at its top with a split sleeve clamp tightened by means of bolt I|2 on the outer shaft housing sleeve 3| which terminates at the exhaust chamber I|3 formed in the casting ||8. At the bottom of the exhaust chamber is a socket ||4 and a partition wall ||5 directing the exhaust gases rearwardly into the discharge pipe ||6 which is bolted at the rear of casting ||8 and constitutes a rearward extension thereof, the anti-cavitation plate ||8 being continuous across the outside of both castings. The discharge mouth I |1 for the exhaust gases is located below plate ||8 and at the rearof the path of the propeller |28.

The inner casing 32 constituting the shaft housing extends clear across the exhaust chamber I3 and seats in the socket ||4 where packing is provided at |2| to prevent the exhaust gases and water from penetrating along the drive shaft 36 into the gear chamber |23. The drive shaft A has a bearing in a bushing |24 immediately above the gear chamber. At its end it carries the drive pinion |25 which meshes with a driven gear |26 bearing in a bushing |21 provided directly in the lower unit casting ||8.

Bolted to the aft surface of the lower unit casting ||8 is a casting |38 which provides a closure for the rear side of the gear chamber and also provides a pump casing |32. The propeller shaft |35 has its forward bearing within the driven gear |26 and its rearward bearing in a bushing provided in casting |38 constituting the gear casing closure. Motion is transmitted from the driven gear |26 to the propeller shaft through a torsion spring |36 having one end entering the gear and the other end anchored in the pump cam |31 which is keyed to the shaft. The torsion spring |36 is wound about the portion of the shaft intervening between the gear and the cam and provides a resiliently flexible driving connection calculated to absorb some of the shock to which the propeller may be subject. A shear pin |38 passing through the shaft is engaged in a notch in the hub of propeller |28, the hub being housed to the pin by the nut |39 screwed to the end of the shaft.

The water inlet provided by the cage communicates through the cylinder head |48 with the cylinder bushing |42 and with the replaceable tubular outlet valve seat member |45. On each displacement stroke of the piston against the compression of spring |50, water is forced through the outlet valve |5| and fitting |52 into the water supply pipe 31 which extends upwardly through the shaft housing between the inner and outer tubes thereof in the manner already described. Because o f the presence of the inner tube no vibration can bring the supply pipe 31 into frictional contact with the rotating drive shaft 36.

In addition to the protection provided by the spring |36 and shear pin |38 -against injury due to the propeller shock, I have mounted the entire outboard motor to tilt upon the bracket pintle 22 whenever the skeg |545 strikes a shoal or obstacle. The thrust bearing sleeve |55 carried by the intermediate portion of the shaft housing can move freely away from the semi-tubular thrust bearing pad 25 of the bracket as long as the motor is being operated in a forward direction. Because the reversal of the motor will cause its thrust to be directed rearwardly and therefore will cause bodily oscillation thereof about the pintle 22, a reverse lock comprising a fitting |51 carrying a senil-tubular flange |58 is clamped to the shaft housing in a position such thail when the motor is rturned bodily in the swivelled bearing 20, as for reversal, the flange |58 will engage behind the thrust bearing pad 25 to interlock the parts against tilting. Since the rearward thrust of the propeller is on such occasions exerted entirely through the lower extremity of the pad 25, the key 21 integrally carried by the pad as above described, is oi' value in preventing the pad from tilting about its clamp screw 28 during reversal.

Those skilled in the art will lnd in the device herein disclosed a unitary design in which the structures and purposes of all parts have been integrated. Many features which have heretofore been aggregated in existing motors have here been modified to take into account the presence of each other. In the foregoing description I have attempted to point out how the provision of under water exhaust in a fully reversible swiveled motor has led to changes in the construction of the engine, the lower unit, and the cooling and exhaust systems. In fact the outboard motor is a new organization throughout in order to correlate my objectives in aIsingle unitary combination.

I claim:

1. In a device of the character described, the combination with a shaft housing and an engine crank case connected therewith, said shaft housing providing an exhaust passage with a laterally opening port and said crank case and shaft housing having an approximately planiform surface through which said port opens, of a cylinder connected with said crank case at said surface and provided with an exhaust passage portion connected with said shaft housing at said surface, said cylinder overlapping the connection between the crank case and shaft housing.

2. In an outboard motor, the combination with a drive shaft, of a shaft housing comprising inner and outer casings in spaced relation, and terminal means connecting said inner and outer casings unitarily together, the space between said casings constituting an c xhaust passage for which said terminal means provide inlet and discharge ports, the outer casing terminating short of said ports and the inner casing projecting beyond said ports at both of said terminal means.

3. In a device of the character described, the combination with a shaft housing comprising a terminal casting having a tiller connection, of a power head mounted on said casting and comprising an engine having its crank case in connection with said casting, and a cylinder block projecting laterally from said crank case, a fuel tank encircling that side of said crank case remote from said cylinder block, and a shroud for said cylinder casting enclosing said casting and having its side walls constituting rearward extensions of the side surfaces vof said fuel tank.

4. In a device of the character described, the combination with a block having bores providing a plurality of cylinders and having exhaust ports opening laterally from said cylinders, of meansprojecting from the ported side of the block to constitute a seat to provide a recess with which said ports communicate, and a closure detachably connected with said seat and having a recess complementary to that of said block, said closure and block together providing an expansion chamber for receiving the discharge through said exhaust ports, and said block having an exhaust discharge passage opening from said expansion chamber and about which said seat is substantially continuous, whereby exhaust gases are admitted to said chamber and delivered therefrom solely through said block.

5. In a device of the character described, the combination with a cylinder block having a cylinder bore and a port opening lateraiy therefrom, of seat means projecting laterally from said block and encircling said port, said seat v means having an exposed face constituting a seat and surrounding a recess within said seat and means with which said port communicates, said block being provided with an exhaust passage leading from said recess beneath said seat, and a closure having a face complementary to said seat, whereby said closure and block together provide an expansion chamber to which exhaust is delivered through said port and from which exhaust is discharged through the passage in said block.

6. In a device of the character described, the combination with a cylinder block having a cylinder bore and a port opening laterally therefrom, of seat means projecting laterally from said block and encircling said port, said seat means having an exposed face constituting a seat and surrounding a recess within said seat and with which said port communicates, said block being provided with an exhaust passage leading from said recess beneath said seat, and a closure having a face complementary to said seat, whereby said closure and block together provide an expansion chamber to which exhaust is delivered through said port and from which exhaust is discharged through the passage in said block, said block and closure having jackets and being provided with water communication passages extending through said seat and face.

7. A device of the character described, com- 75 prising a cylinder block provided with a plurality of parallel and adjacent cylinder bores and having exhaust ports and intake ports opening from said cylinder bores laterally to the same side of the block, a crank case subdivided to provide separate crank cases corresponding to the respective cylinders and with which the respective intake ports are adapted for communication, pistons reciprocable in the cylinders controlling such communication and controlling exhaust through the exhaust ports, flange means outstanding from said block about said exhaust ports to provide a recess with which said ports communicate, the periphery of said ange means being surfaced to constitute a seat and said block having an exhaust passage communicating with said recess beneath said seat, and a closure for said recess whereby to constitute said recess as an expansion chamber, said closure being internally provided with passages registering with the intake ports of said block and a carburetor mounting flange ported in communication with said passage.

8. In a device of the character described, the combination with an upright crank shaft and a. crank case provided with bearings therefor, of pistons in operative connection with said shaft, a cylinder block having cylinder bores in which the pistons are reciprocable, said bores having intake ports communicating with the crank case and exhaust ports on the same side of the cylinder block opening from the respective cylinders, the crank case being subdivided into separate crank case chambers individual to the refspective cylinders, means on the side of the cylinder block providing a. seat encircling the exhaust ports therein, a chambered closure on said seat constituting an expansion chamber with which said ports communicate, said block containing an exhaust passage leading :from said chamber, and charge forming and delivering means connected with said closure and comprising passage means leading to the respective intake ports.

said means communicates and from which said 'passage leads to said shafthousing.

10. In an outboard motor, the combination with a shaft housing comprising an exhaust passage having a lateral inlet opening adjacent its upper end, of an engine crank case connected with said shaft housing, a cylinder block having a cylinder portion connected with the crank case and provided integrally with an exhaust passage formed in said block, said block including a portion through which said exhaust passage extends to said inlet opening, said last mentioned cylinder block portion being connected with said shaft housing whereby said cylinder block is connected across the connection between the crank case and the shaft housing, means on the side of the cylinder block providing a seat and a recess within the seat from which said integral exhaust passage leads, said cylinder block having exhaust port means opening into said recess within said seat in communication with said passage, and a closure applied to said seat and constituting said recess, an expansion chamber adapted to receive gases exhausted from said cylinder block through the exhaust port thereof and to deliver said gases back through the passage of said block into said shaft housing.

WARREN C. CONOVER.