Marine outboard gear assembly
Abstract
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.
Description
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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