Marine outboard gear assembly

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Marine outboard gear assembly

The invention contemplates a gear assembly outboard marine engine, for use in an outboard or indoor-outdoor unit, and with (a) constant unit meshing gears that transfer power to the axis of the propeller shaft, and (b) selectively direct spring-gripping propeller shaft, which (c) the use of meshing gears for flow of lubricant when the engine is running and whether or not the clutch is coupled and (d) reducing to an absolute minimum the effects of inertia and drag on the propeller shaft operation when the boat is moving in the disengaged condition, ie, bow propeller. There is also a particular subset of gears and clutch parts in the propeller shaft so that the desired axial clearance can be adjusted and pre-selected before installation of the gearbox easily.

This application is a continuation in part of my copending application, Ser No. 499292, filed on August 21, 1974.This invention relates to the construction of drive gear outboard marine and has particular utility in smaller sizes of outboard motors, although the principles of the invention are also applicable to outboard motors and larger for drive units inward-outboard.It is an object of the invention to provide an improved construction of the character indicated.Another object is to provide improved lubrication for the complete drive train of a set of outboard marine character indicated, regardless of enabled or disabled status of the unit and as long as the engine is running.Is a specific object to provide a construction of the character indicated, wherein the axial clearances of the parts made by the propeller shaft can be easily adjusted and preset.A further specific object is to meet the above objects with a construction in which the location of the seized participation of engine power to the propeller shaft is the propeller shaft itself.A general object is to achieve the stated objects, with relative simplicity of construction, reliability of operation, ease of maintenance and low cost, and which offers minimal resistance resistance to rotation of the propeller when in disengaged condition .Other objects and various other features of novelty and invention will be pointed out or will occur to those skilled in the art from a reading of the following specification in conjunction with the accompanying drawings. In the drawings, which show, for illustrative purposes, a preferred form of the invention: 
. Figure 1 is a vertical sectional view through the major part of the assembly portion of a gear box assembly outboard marine drive of the invention;. Figure 2 is a plan view of one part of the whole mark figure. 1.The invention is shown in application to an assembly comprising a gear box 10 having holes 11 to 12 of intersection of the vertical and horizontal axes for the pivotal accommodation of a vertical drive shaft 13 and a propeller shaft 14 . The gearbox 10 includes several other vertical passages such as a lubricant passage 15 and a passage-control element 16, and the lower end of the housing includes forming a vane or slide 17 for the lower blade protection scanning propeller (not shown) carried on the splined end 18 projecting outside the shaft 14.A bevel drive gear 20 at the lower end of shaft 13 is in constant mesh with a bevel gear 21 which is driven or rotating with respect to a reduced cylindrical surface 19 near the inner end of the propeller shaft 14. As shown, a splined coupling 22 connecting the adjacent ends of the drive shaft 13 and the head portion of the shaft 23 of the sprocket 20; needle assemblies 24-25 establish their spaced rollers rotatably mounted in the bore 11 concentric and a thrust washer 26 axially locates the gear 20 cast gearbox.Points axially spaced bearing support are also available for the shaft 14. A first of these is a set of needle-roller 27 mounted in the bore of a ring plate member or support bearing 28 which is shown to have an inner circular base flange mounted in a countersunk portion 29 in the helix -axis bore 12, an outer circular rim of the support 28 also supports a countersunk portion of the propeller shaft hole 12, being introduced by means 30 against rotation therein. A clamping ring 31 is threaded engagement with the threaded outer end of the counterbore 32 and retains the assembly, as will be explained in more detail. Needle roller means 27 mount a central cylindrical surface 33 of shaft 14 and seal means 34 mounted on the support 28 is also applied to the surface 33.
The second point of propeller support shaft is provided by friction-bearing means 35, shown as a set of larger ball bearing rings with inner and outer race and having the load capacity combined radial and thrust . Bearing 35 directly supports the driven gear 21, and the reduced cylindrical surface 19 of the shaft 14 is rotatably positioned by the engaging hole 21. As shown, a threaded nut or ring 36 secures the bearing inner ring 35 against a shoulder on the gear 21, and the outer ring of the bearing 35 is supported and the counterbore 29, being driven against a wedge 35 'and the radial shoulder 37 in the bore 29 that ends, the axial location against the shoulder 37 is applied by the clamping ring 31 through a thrust washer stainless steel 31' the bearing 28, a ring Spacer 38 and bearing outer ring 35 and a resilient O-ring 39 carries at one end ring 38 relief complete seal integrity of the inner volume and the content of the gearbox 10. Local axial projection 28 'of support 28 in the angular space defined between the locating lugs 38' in the spacer ring 38 secures the keyed orientation ring 38 relative to the housing, through key means 30, to provide the alignment shift shaft 52 with the passage through ring 38, as illustrated.A cylindrical shaft portion 40 of greater radius, between surfaces 19 and 33, establishes a shoulder 41 which serves a location axial direction of the shaft 14. A thrust washer 42 may be interposed between the gear 21 and the shoulder 41 to hold the spring coils 50 clear, but not essential, since the propeller shaft 14 will always be pushed forward by the thrust of the propeller when clutch 50 is engaged. The axial end of the inner shaft 14 is threaded to accept stop-nut means 43 and fit against a washer 44 to limit axially the other direction of movement of the shaft 14. Washer 44 (see Fig 2.) Keyed connection is formed to the shaft 14, which is shown with a chordal flat 45 into its hole, to match a local flat 46 milled on the inner end of shaft 14. The clearance between the shoulder 41 and the gear 21 is adjusted by adjusting the stop-nut 43 to prevent downward wrap coil spring 50 between the gear 21 and shoulder 41.To complete the picture, and as a feature of the invention, clutch means carried on the propeller shaft axis provides selective engagement and disengagement of all the drive train to the element ultimately driven, namely the -axis propeller itself. As shown, and preferably at least for applications outboard-motor smaller such clutch means is in the range of the coil spring, as shown and described, for example, to a different setting in Armstrong U.S. Patent n. No. 2760613. This involves close multiple clutch spring stock turns, preferably rectangular and cylindrical surfaces adjacent overlapping matching, ie the same radius, in the parts that are made selectively. As shown, the end of the gear hub 21 is reduced to establish a cylindrical surface 49 of radius equal to that of the shaft surface 40 and a helical coil spring 50 overlaps both these surfaces. Spring 50 is located between the axis of a bead or shoulder 50 'and the shoulder defined by the formation of the reduced surface 49, and, in accordance with the description in said patent, one end of spring 50 is bent out of Helix (eg tangential to the path of the propeller) to define a toe 51 rotating sweeping toe after rotation 51 is driven in the path of selective axial movement of a control element or rod 52 (in step 16), remotely operable by means not shown. In its retracted position, the rod 52 clears the path of movement of the toe actuated and the clutch 51 remains activated, thus locking the gear 21 to shaft 14 for driving the boat, in its projected position towards below, the rod 52 intersects toe 51 to relieve all clamping action of the spring 50 on the surface 49, thereby disengaging the shaft 14 around the drive mechanism. Means that the finger 51 is formed to escape harmlessly rod 52 in the case of reverse rotation drive which can accompany a back fire or kick-back of the engine, all as described in said patent .The described construction will be seen to have gotten all the items listed in a particularly effective. As to lubrication, the gear gears 20 to 21 are caused to run while the engine is running, regardless of the ON or OFF condition of the clutch means 50, the gear box was packed with lubricant, with the level of conventional filling port and plug 53, and therefore the steady running of the gears 20 to 21 signify the lubricant circulation continued at all times, such as upward in the hole 15, to through opening 54 and down the passage space remaining within bore 11. A passage 54 'between holes 11 and 16 completed a vent line between the holes 11, 15 and 16 which prevents air entrapment when adding or changing the oil.Manipulating the washer 44 to the propeller shaft 14 means no relative rotation of gear 21 on shaft 14 can never be the cause of the loss of preselected configuration stop-nut means 43 in the shaft 14. Moreover, the gear ratio 21, which leads 35 and the clutch 50 on the shaft 14 means that together constitute a sub manipulation unit, accessible for maintenance and adjustment when removed from the box body gear; unscrewing of release ring 31 allows easy removal of carrier 28, key 30, and the spacer 38, together with and without disturbing the integrity of the manipulation unit of this subset. Furthermore, mounting the gearbox key 30 ensures correct angular registration, and the shoulder 37 ensures correct axial positioning gear meshing 20-21. No amount of clamping force through the ring 31 can alter or impair these relationships, nor can a particular preselected axial-gap, clearance, or preload through nut means 43 be affected by such fixation. Thus, for example, for an application 4 horsepower, 40 ft-lb torque application is recommended for embracing the ring 31, while the stop-nut 43 is adjusted to provide a clearance of 0.010 (0.254 mm) and 0.015 inch (0.381 mm) between the shoulder 41 and the adjacent end gear 21.While the invention has been described in detail to the preferred embodiment, it is understood that modifications can be made without departing from the scope of the invention.


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