US2609783A

US2609783A - Gear case and propeller shaft bearing for outboard motors

Info

Publication number: US2609783A
Application number: US225813A
Authority: US
Inventors: Elmer C Kiekhaefer
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-05-11
Filing date: 1951-05-11
Publication date: 1952-09-09
Anticipated expiration: 1969-09-09

Description

p 9, 1952 E. c. KIEKHAEFER 2,609,783

GEAR CASE AND PROPELLER SHAFT BEARING FOR OUTBOARD MOTORS Filed May 11, 1951 2 SHEETS-SHEET 1 ,1" 38 /4- i i I 1 l 2 1Z2 1 l '1 /9 i 20 /4 36 4 2a 42 25 3512/ 27 AZ 4/ E Z7 28 32 4a IN VEN TOR.

filler/rays Sept. 9, 1952 Filed May 11 1951 E. C. KIEKHAEFER GEAR CASE AND PROPELLER SHAFT BEARING FOR OUTBOARD MOTORS.

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INVENTOR. (721?!" fil kfia9 er mum Patenteri Sept. 1952 orFicE GEAR CASE AND PROPELLER. SHAFT BEARING FOR OUTBOARD MOTORS Elmer C. Kiekhaefcr, Cedarhurg, Wis.

Application May 11, 1951, Serial No. 225,813

8 Claims.

This invention relates to outboard motors and particularly to the underwater unit thereof.

The invention provides a lower unit having an improved bearing and gear assembly and water intake means especially adapted for high speed operation.

The principal object of the invention is to reduce the frontal area of the unit and the drag while providing for the adequate bearing support of the propeller shaft at higher operating speeds of the motor.

Another object is to provide a lower unit adapted to transmit more power at higher speeds without mechanical failure or breakage of the gear case.

A more particular object is to support the full length of the propeller shaft and prevent deflection of the shaft.

These and other objects and advantages will be more fully set forth in the following description of the invention as illustrated in the ac companying drawings.

In the drawings:

Figure 1 is a vertical, longitudinal cross-section of the outboard motor lower unit; and

Fig. 2 is a similar view of an alternate embodiment of the invention in a similar lower unit.

Units I and 2, shown in Figures 1 and 2, respectively, comprise the lower, underwater mechanisms of outboard motors which are adapted to be secured to the transom of a boat, not shown, and pivotally supported for turning on a vertical axis to effect the directional control of the boat.

Each lower unit supports a propeller 3 for rotation and includes the gear case 3. The hub 5 of propeller 3' carries the blades 6 of the propeller which rotate at high speed andare subject to striking objects which can damage the gear case and interfere with the operation of the motor.

Units l and 2, are identical, except as hereinafter described, and carry the lower end of the drive shaft 1 of each unit. In each embodiment of the invention the drive shaft 1 is connected at its upper end to the engine of the motor and carries the drive beveled gear 8 at its lower end and in mesh with the driven beveled gear 9 mounted on the propeller shaft It to drive propeller 3.

The gear case d comprises a single, cast member generally including the strut l i, the enlarged torpedo section l2 and the skeg 13 which extends as a thin, downwardly projecting fin from the underside of the torpedo section.

The strut l I is formed with a chamber [4 which opens upwardly from the upper planiform face [5 thereof and is secured by the forward and rear tie bolts IB'and ll, respectively, to the lower end of the motor. The upper and lower bearings l8 and 19, respectively, journally support drive shaft 1 in chamber M. The upper bearing [8 is seated in a suitable bore against the shoul der 20 formed in the strut H near the upper end thereof and with the seal 2i mounted thereover on shaft 1. The shoulder 22 engages the inner race of bearing iii to transmit the axial thrust of gear 3 thereto. The lower bearing I9 is preferably a needle or roller bearing unit with a minimum outer diameter and is disposed within the lower end of strut H to support the'lower end of shaft I immediately above torpedo section and gear 8.

The torpedo section l2 of gear case 4 is formed with a chamber 23 which opens rearwardly thereof and communicates forwardly with the lower end of chamber Hi. The lower end of drive shaft 1 projects into chamber 23 and carries gear 8 therein in an enlarged pocket forming a part of chamber 23 in the gear case to accommodate the gears.

The forward bearing 24 is seated in the bored forward end of chamber 23 and supports the forward end of shaft H3.

The larger bearing 25 is secured and fits a corresponding bore 2% at the rear of chamber 23 and is disposed against the shoulder 2! formed therein and facing rearwardly thereof. The'inner race of bearing 25 supports directly thehub of gear 9 and the ring 28 axially secures the inner race of bearing 25 and the gear. The pin.29 secures the hub of gear 9 and shaft it on which the gear is mounted and the shaft is supported intermediate the ends thereof.

The pump unit which supplies the engine of power head I with coolant under pressure is mounted on shaft It rearwardly of bearing 25 and includes the impeller 36 rotationally secured on shaft l6 within the pump body 3| which houses the impeller. Pump body 3| is cylindrical to fit Within bore 25 and is provided with

suitable seals

32 and 33 respectively engaging shaft ill and the walls of the torpedo to close chamber 23.

The inlet and

outlet ports

34 and 35 of pump body 3| register respectively with the intake ports not shown and discharge passage 35 formed in the gear case. Passage 36 extends from chamber 23 rearwardly of seal 33 upwardly within strut II and is fitted with the seal 31 in the up- 3 per face 15 of the strut to receive the lower end of delivery conduit 38 connected to the coolant system of the motor.

The conical member 39 shown in Figure l fitted within the rear opening of chamber 23 engages the pump body 3! to secure the latter therein and to expand seal 33 against bore 26 to close the same tightly and secures also bearing 25 against shoulder 22 to prevent axial displacement of shaft l and gear 9. According to the invention the bearing 40 carried in the rear end of member 35 is disposed to support the rear projecting end of shaft l0 against deflection and is dimensioned to provide a nominal clearance between the shaft and the bearing surface so that under ordinary conditions of service no bearing load is exerted or carried and frictional losses are substantially avoided. In the event of undue vibration or deflection of shaft If] as when propeller 3 strikes an object bearing 40 supports shaft l8 against bending and misalignment. According further to the invention, the alignment of bearing to with bearings 2d and 25 is established by shaft It in the assembly of the unit and is maintained by the shoulder 21 and bearing 25 through pump body 31. The mechanical difliculties normally encountered in maintaining the alignment of three spaced bearings is effectively avoided so that the clearances are maintained between bearing All and shaft H3. The normal clearances of the threads M of gear case 4 and member 353 provides all the necessary radial adjustment of member 39 which ordinarily needs to be effected. In the assembly of the unit, the bearing 25, gear 9 and the pump may be inserted in bore 26 as a sub-assembly. The shim 32 may be inserted between shoulder 21 and bearing 25 as required. As member 39 is turned in threads 4! the forward face of the member contacts the rear face of pump body 3! and the alignment of bearing M3 is automatically effected. Member 39 is tightly secured thereafter by further turning and tightening and the alignment established by shaft if] is maintained accordingly.

The inner conical member 33 shown in Fig. 2 carries the roller bearings M- which support the rear projecting ends of shaft ii! at all times and is adapted particularly for larger units where the shaft transmits a higher power output, The outer cone 45 shown in Fig. 2 is threaded in the rear open end of chamber 23 to engage the flange 45 of member 43 and secure the latter in contact with the rear face of the pump body 2!. A clearance provided between flange at and gear case provides for radial adjustment of member d3 which is established by shaft It and maintained by tightening cone 45.

In both embodiments of the invention, the alignment of bearings 24 and 25 and the bearings supporting the projecting end of shaft it is provided for in the initial assembly of the unit and is only indirectly affected by manufacturing tolerances. Member 39 and cone 45 extend rearwardly of the strut II of the gear case i and are shaped to continue the streamlines of torpedo 52 up to the hub 5 of propeller 3.

Various embodiments of the invention may be employed within the scope of the following claims.

I claim:

1. In an outboard motor lower unit, a gear case member having an enlarged torpedo section at the lower end of a narrower supporting strut, said member comprising a cast housing having a chamber formed therein and including a bore within the forward end of said torpedo section and a larger rear bore axially aligned with said first bore and spaced therefrom and opening rearwardly of said torpedo section, a drive shaft journally supported within said strut, a drive gear carried by said drive shaft within said chamber between said bores, a propeller shaft extending from said chamber and extending through said larger bore and rearwardly of said gear case, a driven gear fixed on said shaft in said chamber and in mesh with said drive gear, a first bearing carried by said housing in said forward bore journally supporting the forward end of said propeller shaft, a second bearing mounted within said larger bore rearwardly of said drive gear and supporting said shaft intermediate the ends thereof and said driven gear thereon, a shoulder formed within said larger bore facing the open end thereof and disposed to locate and support said second bearing against axial displacement, a closure member secured within the open end of said bore against said second bearing to secure the latter against said shoulder and to secure said driven gear and propeller shaft against axial displacement, and a third bearing carried by said closure member supporting the rear end of said propeller shaft and maintained in alignment with the alignment of said first and second bearings by said. shoulder.

2111 an outboard motor lower unit, a gear case housing having a chamber formed therein and including a bore within the forward end thereof and a larger rear bore axially aligned with said first bore and spaced therefrom and opening rearwardly thereof, a drive shaft and a drive gear carried by said drive shaft within said chamber between said bores, a propeller shaft extending from said chamber and extending through said larger bore and rearwardly of said housing, a driven gear fixed on said shaft in said chamber and in mesh with said drive gear, a first bearing carried by said housing in said forward bore journally supporting the forward end of said propeller shaft, a second bearing mounted Within said larger bore rearwardly of said drive gear and supporting said shaft intermediate the ends thereof and said driven gear thereon, a shoulder formed within said larger bore facing the open end thereof and disposed to locate and support said second bearing against axial and angular displacement, a closure member secured within the open end of said bore against said second bearing to secure the latter against said shoulder and to secure said driven gear and propeller shaft against axial displacement, and a third bearing carried by said closure member supporting the rear end of said propeller shaft and maintained by said shoulder in alignment with the alignment of said first and second bearings initially established by the shaft.

3. In an outboard motor lower unit, a gear case housing having a chamber formed therein and including a bore within the forward end thereof and a larger rear bore axially aligned with said first bore and spaced therefrom and opening rearwardly thereof, a drive shaft and a drive gear carried by saiddrive shaft within said chamber between said bores, a propeller shaft extending from said chamber through said larger bore and projecting rearwardly of said housing, a driven gear fixed on said shaft in said chamber and in mesh with said drive gear, a first bearing carried by said housing in said forward bore journally supporting the forward end of said propeller shaft, a second bearing mounted within said larger bore rearwardly of said drive gear and supporting said shaft intermediate the ends thereof and said driven gear thereon, a shoulder formed within said larger bore facing the open end thereof and disposed inwardly thereof and to locate and support said second bearing against axial and angular displacement, a closure member secured within the open end of said bore against said second bearing to secure the latter against said shoulder and to secure said driven gear and propeller shaft against axial displacement, and a third bearing carried by said closure member and maintained by said shoulder in alignment with the alignment of said first and second bearings initially established by the shaft and disposed to support the projecting end of said propeller shaft against a given maximum deflection.

4. In an outboard motor lower unit, a gear case housing having a chamber formed therein and including a bore within the forward end thereof and a larger rear bore axially aligned with said first bore and spaced therefrom and opening rearwardly thereof, a drive shaft and a drive gear carried by said drive shaft Within said chamber between said bores, a propeller shaft extending from said chamber through said larger bore and projecting rearwardly of said housing, a driven gear fixed on said shaft in said chamber and in mesh with said drive gear, a

first bearing carried by said housing in said for- Ward bore journally supporting the forward end of said propeller shaft, a second bearing mounted within said larger bore rearwardly of said drive gear and supporting said shaft intermediate the ends thereof and said driven gear thereon, a shoulder formed within said larger bore facing the open end thereof and disposed inwardly thereof and to locate and support said second bearing against axial and angular displacement, a closure member secured within the open end of said bore against said second bearing to secure the latter against said shoulder and to secure said driven gear and propeller shaft against axial displacement, and a third bearing carried by said closure member and maintained by said shoulder in alignment with the alignment of said first and second bearings initially established by the shaft and disposed to support the projecting end of said propeller shaft against a given maximum deflection, said shaft being otherwise supported by said first and second bearings independently of said third bearing.

5. In an outboard motor lower unit, a gear case housing having a chamber formed therein and including a bore within the forward end thereof and a larger rear bore axially aligned with said first bore and spaced therefrom and opening rearwardly thereof, a drive shaft and a drive gear carried by said drive shaft within said chamber between said bores, a propeller shaft extending from said chamber through said larger bore and projecting rearwardly of said housing, a driven gear fixed on said shaft in said chamber and in mesh with said drive gear, a first bearing carried by said housing in said forward bore journally supporting the forward end of said propeller shaft, a second bearing mounted Within said larger bore rearwardly of said drive gear and supporting said shaft intermediate the ends thereof and said driven gear thereon, said housing having a shoulder formed at the inner end of said larger bore and facing the open end thereof to locate and support said second bearing against axial and angular displacement, a cylindrical pump body disposed within said bore rearwardly of and against said second bearing, a closure member secured within the open end of said bore against said pump body to secure the latter therein and said second bearing against said shoulder and tosecure said driven gear and propeller shaft against axial displacement, said closure member being subject to radial adjustment in said bore and a third bearing carried by said closure member disposed to support the projecting end of said propeller shaft and maintained by said shoulder in alignment with the alignment of said first and second bearings as initially established by the shaft.

6. In an outboard motor lower unit, a gear case housing having a chamber formed. therein and including a bore within the forward end thereof and a larger rear bore axially aligned with said first bore and spaced therefrom and opening rearwardly thereof, a drive shaft and a drive gear carried by said drive shaft within said chamber between said bores, a propeller shaft extending from said chamber through said larger bore and projecting rearwardly of said housing, a driven gear fixed on said shaft in said chamber and in mesh with said drive gear, a first bearing carried by said housing in said forward bore journally supporting the forward end of said propeller shaft, a second bearing mounted within said larger bore rearwardly of said drive gear and supporting saidshaft intermediate the ends thereof and said driven gear thereon, said housing having a shoulder formed at the inner end of said larger bore and facing the open end thereof to locate and support said second bearing against axial and angular displacement, a cylindrical pump body member disposed within said bore rearwardly of and against said second bearing, a closure member Within the open end of said bore against said pump body member, means to secure said members in said bore and said second bearing against said shoulder and to secure said driven gear and propeller shaft against axial displacement, said closure member being subject to radial adjustment in said bore, and a third bearing carried by said closure member disposed to support the projecting end of said propeller shaft and maintained by said shoulder in alignment with the alignment of said first and second bearings as established by the shaft.

7. In an outboard motor lower unit, a streamlined gear case housing having a torpedo section with a chamber formed therein and including a bore within the forward end thereof and a larger rear bore axially aligned with said first bore and spaced therefrom and opening rearwardly thereof, a drive shaft and a drive gear carried by said drive shaft within said chamber between said bores, a propeller shaft extending from said chamber through said larger bore and projecting rearwardly of said housing, a driven gear fixed on said shaft in said chamber and in mesh with said drive gear, a first bearing carried by said housing in said forward bore journally supporting the forward end of said propeller shaft, a second bearing mounted within said larger bore rearwardly of said drive gear and supporting said shaft intermediate the ends thereof and said driven gear thereon, said housing having a shoulder formed at the inner end of said larger bore and facing the open end thereof to locate and support said second bearing against axial and angular displacement, a cylindrical pump body disposed rearwardly within said bore against said second bearing, a closure member secured within the open end of said bore against said pump body to secure the latter therein and said second bearing against said shoulder and to secure said driven gear and propeller shaft against axial displacement, and a third bearing carried by said closure member disposed to support the projecting end of said propeller shaft and maintained by said shoulder in alignment with the alignment of said first and second bearings initially established by the shaft, said closure member extending rearwardly of said housing and forming the rear streamlines of the torpedo section thereof.

8. In an outboard motor lower unit, a streamlined gear case housing having a torpedo section with a chamber formed therein and including a bore within the forward end thereof and a larger rear bore axially aligned with said first bore and spaced therefrom and opening rearwardly of the housing, a drive shaft and a drive gear carried by said drive shaft within said chamber between said bores, a propeller shaft extending from said chamber through said larger bore and projecting rearwardly of said housing, a driven gear fixed on said shaft in said chamber and in mesh with said drive gear, a first bearing carried by said housing in said forward bore journally supporting the forward end of said propeller shaft, a second bearing mounted within said larger bore rearwardly of said drive gear and supporting said shaft intermediate the ends thereof and said driven gear thereon, said housing having a shoulder formed at the inner end of said larger bore and facing the open end thereof to locate and support said second bearing against axial and angular displacement, a cylindrical pump body disposed rearwardly within said bore against said second bearing, a closure member within the open end of said bore and disposed against said pump body, a cone member threaded in th open end of said bore to secure said pump body therein and said second bearing against said shoulder and to secure said driven gear and propeller shaft against axial displacement, and a third bearing carried by said closure member disposed to support the projecting end of said propeller shaft and maintained by said shoulder in alignment with the alignment of said first and second bearings as established by the shaft, said cone member extending rearwardly of said housing and forming the rear streamlines of the torpedo section thereof.

ELMER C'. KIEKHAEFER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS llumber Name Date 2,064,195 Michelis Dec. 15, 1936 2,434,312 Downs Jan. 13, 1948