Note: Descriptions are shown in the official language in which they were submitted.
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BEVEL GEAR ASSEMBLY
BACKGROUND OF THE INVENTION
1. Fi~ld of the Invention
This invention relates to bevel gears, and, more
particularly, to bevel gears in the shift apparatus of a
reversible transmission in a marine propulsion device.
2. DescriPtion of the Prior Art
The prior art relating to the shift apparatus for
shifting a reversible transmission of a marine propulsion
device typically includes a control member which is movable
axially of the propeller shaft for actuating the transmission.
The shift apparatus provides means for moving the control
member axially in response to operator actuation of a remotely
located control device. The operation of a marine propulsion
device shift apparatus is further described in U.S. Patent
4,849,147 to Higby et al. which is hereby incorporated by
reference.
Known bevel gears utilized in these transmissions are
one-piece constructions with the lugs of the gear machined
directly into the face of the gear. One consequence of
machining the lugs directly into the face of the gear is that
if the lugs are damaged the entire gear will be damaged.
Attention is directed to the following U.S. Patents:
Patent Number Inventor Issue Date
4,865,570 Higby et al. September 12, 19)39
4,621,714 Skurka November 11, 1986
3,724,612 Spain April 3, 1973
1,913,802 Gregory June 13, 1933
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SUMMARY OF THE INVENTION
The invention provides a marine propul~ion device
comprising a housing, a propeller shaft supported by the
housing and adapted to carry a propeller, a first bevel ~ear
assembly comprising a f irst gear port.ion rotatable relative to
the propeller shaft, a first lug portion, and means for
removably securing the first lug portion to the first qear
portion for common rotation therewith, a clutch dog connected
to the propeller shaft for common rotation therewith and for
axial movement relative thereto, and means for moving the
clutch dog into and out of engagement with the first lug
portion.
The invention also provides a bevel gear assembly
comprising a gear portion includi.ng a hollow, generally
cylindrical body portion, a bevel gear portion extending from
the cylindrical body portion, a lug portion having thereon a
lug, and means for securing the lug portion to the gear portion.
The invention also provides a marine propulsion device
comprising a housing, a propeller shaft supported by the
housing and adapted to carry a propeller, a first bevel gear
assembly comprising a first gear portion rotatable relative to
the propeller shaft, a first lug portion, and means for
removably securing the first lug portion to the first gear
portion for cornmon rotation therewith, a second bevel gear
portion comprising a second gear portion rotatable relative to
the propeller shaft, a second lug portion, and means for
removably securing the second lug portion to the gear portion
for common rotation therewlth, a clutch dog connected ~o the
propeller shaft for common rotation therewith and for axial
movement relative thereto, and means for selectively and
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alternatively moving the clutch dog into and out of engagement
with the first and second lug portions of the fir3t and second
bevel gear assemblies.
A principal feature of the inven~ion is the provision
of a bevel gear asse~bly which has a separate gear portion and
a separate lug portion and means for securing the lug portion
to the gear portion. This separate lug portion will reduce the
need to replace the entire gear assembly when only the lug
portion or the gear portion is damaged.
Also, a separate lug portion will permit the use of a
single gear design with multiple lug 9eometries. This will
reduce manufacturing costs in that it will not be necessary to
produce and keep in inventory smaller quantities of nearly
identical gears.
Other principal features and advantages of the
invention will become apparent to those skilled in the art upon
review of the following detailed description, claims and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a marine
propulsion device embodying the invention.
FIG. 2 is an enlarged, vertical cross-sectional view
of the shift apparatus.
FIG. 3 is an exploded prospective view of the bevel
gear assembly.
Before one embodiment of the invention is explained in
detail, it is to be understood that the invention is not
limited in its appl:;cation to the details of construction and
the arrangement of components set forth in the following
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description or illustrated in the drawings. The invention is
capahle of other ~mbodiments and of being practiced or carried
out in various way3. Also, it should be understood th~t the
phraseology and terminology used herein is for the purpose of
description and should not be regarded as limitin~.
DESCRIPTION OF THE PREFERRED EMBODIMENT
A marine propulsion device 10 embodying the invention
is illustrated in FIG. 1. The marine propulsion device 10
comprises a mounting bracket or assembly 12 fixedly mounted on
the transom 14 of a boat.
The marine propulsion device 10 also comprises a
propulsion unit 16 mounted on the mounting assembly 12. The
propulsion unit 16 includes a power head 18 which includes an
internal combustion engine 20. The propulsion unît 16 further
includes a lower unit 22 which supports the power head 18 and
which includes a lower gearcase 24.
As shown in FIGS. 1 and 2, the marine propulsion
device 10 also comprises a generally horizontal propeller shaft
26 having therein an ~ial bore 27, having thereon a propeller
28 (Fig. 1), and being rotatably mounted in the lower gearcase
24. The device 10 also comprises a drive gear 30 (Fig. 2)
rotatably mounted in the lower gearcase 24. The engine 20 is
drivingly connected to the drive gear 30 by a driveshaft 32.
The marine propulsion device 10 further comprises (see
Fig. 2) a reversible transmission 34 for selectively effecting
driving engagement between the dri~e gear 30 and the propeller
shaft 26. While various suitable transmissions can be
employed, in the preferred embodiment, the transmission 34 i~
located in the lower gearcase 24 and includes a pair of axially
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spaced bevel gear a6semblies 36 and 38. Each of the bevel gear
assemblie~ 36 and 38 is comprised of (see FIG. 3~ a gear
portion 42 which is supported in surrounding relation to the
propeller shaft 26 and which is rotatable relative to the
propeller shaft 26. The gear portion 42 further comprises a
hollow, generally cylindrical hub portion 44 which has therein
a central bore 46 throuqh which the propell~r shaft 26 extends,
and a tooth portion 48 which meshes with the drive gear 30 and
which extends from the hub portion 44. Each gear assembly 36,
38 is also comprised of an annular lug portion 50 having
thereon a plurality of lugs 52 and having a central bore 54
which is aligned with the bore 46 in the gear portion 42 and
through which the propeller shaft 26 extends. Each gear
asser~ly 36, 38 is further comprised of means 56 for removably
securing the lug portion 50 to the gear portion 42 for cornmon
rotation therewith. The means 56 for removably securing the
lug portion 44 to the gear portion 42 preferably includes one
or more connecting merQbers extendinq through the lug portion 50
and into threaded apertures S7 in the gear portion 42. Any
suitable connecting member or members, such as bolts or screws,
can be employed.
The transmission 34 al~o include~ (see Fig. 2) a
clu~ch dog 58 which is splined to the propeller shaft 26 for
common rotation therewith and for axial movement relative
thereto.
The transmission 34 also includes means for
selectively and alternatively movinq the clutch dog 58 into and
out of engagement with the lugs 52 on the lug portions 50 o
the gear assemblies 36 and 3~. Preferably, such mean3 includes
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a selector shaft 60 which extends through the axial bore 27 in
the propeller shaft 26 and which is movable axially of the
propeller shaft 26. The selector shaft 60 has thereon a p.n 62
which is engageable with the clutch dog 58 for moving the
clutch dog 58 with the selector shaft 60 axially of the
propeller shaft 26. Thusl the selector shaft 60 is movable
axially of the propeller shaft 2h for selectively and
alternatively causing driving engagement between the gear
assemblies 36 and 38 and the clutch dog 58 and thereby between
the bevel gear assemblies 36 and 38 and the propeller shaft
26. Such a selector shaft and clutch dog arrangement is
di~closed in U.S. Patent No. 3,919,964 to Hagen which iq hereby
incorporated herein by reference.
The transmission 34 transmits forward driving power to
the propeller shaft 26 when the clutch dog 58 is in engagement
with the lugs 52 of one of the bevel gear assemblies 36 and
3~. The transmission 34 transmits reverse driving power to the
propeller shaft 26 when the clutch dog 58 is in engagement with
the lugs 52 of the other of the bevel gear assemblies 36 and
38. The transmission 34 is in neutral when the clutch dog 58
is between and disengaged rom both of the bevel gear
assemblies 36 and 38. Thus, axial movement of the selector
shaft 60 shifts the transmission 34 between forward, neutral
and reverse.
Various features of the invention are set forth in the
following claims.
