Note: Descriptions are shown in the official language in which they were submitted.
9~3~
REVERSE THRUST PROPELLER
BACKGROUND OF THE INVENTION
The invention relates generally to
marine propellers affording "through the hub" exhaust
discharge. More particularly, the invention relates
to marine propulsion devices including an arrangement
for mounting a "through the hub" propeller on a
propeller shaft.
Attention is directed to the following
U.S. patents which illustrate marine propellers:
Inven~or Patent No. Issued
Strang 3,356,151 DecembeL 5, 1967
Shimanckas 3,754,~37 August 28, 1973
Ni~hida, et al. 4,276,036 Juns 30, 1981
Takahashi, st al. 4,436,514 March 13, 1984
Henick 3,748,061 July 24, 1973
Shimanckas 3,467,051 September 16, 1969
SUMMARY OF THE INVENTION
The invention provides a marine
propeller including a hub adapted to be rotated about
an axis and defining an exhaust gas passageway with
an opening, a plurality o~ blades extending outwacdly
from the hub, and a membec located on the hub
forwacdly of the blades, extending forwacdly and
cadially outwardly with respect to the axis, and
adjacent the opening.
In one embodiment, the member at least
partially defines the opening, and the member extend6
curvilinearly forwardly and radially outwardly with
respect to the axis.
In one embodi~ent, the member is
concave when viawed from the axis forward of the
member.
67363-~25
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The invention also provides a marine
propulsion device including a propeller shaft, a
lower unit rotatably supporting the propeller sha~t
and including a lower unit exhaust passageway, and a
propeller adapted to be submerged in water and
including an inner hub connected to the propeller
shaft. The propeller also includes an outer hub
connected to and spaced from the inner hub and
defining a propeller exhaust passageway having an
inlet in communication with t:he lower unit exhaust
passageway, and a plurality of blades extending from
the outer hub rearwardly of the inlet. The device
also includes an opening for communicating the lower
unit exhaust passageway with water outside of the
outer hub, and a member located adjacent and rearward
of the opening, and extending forwardly and radially
outwardly with respect to the propeller shaft.
The invention also provides a marine
propulsion device including a lower unit adapted to
be submerged in water and comprising a propeller
shaft, a gearcase which supports the propeller shaft
for rotation about an axis and which includes a
rearward end, and an outer surface which extends
forwardly from the rearward end, which gearcase also
includes an internal exhaust passageway having, at
the gearcase rearward end, an exhaust gas outlet with
a given diameter, and a propeller including an inner
hub connected to the propeller shaft, and an outer
hub connected to and radially spaced from the inner
hub and defining therebetween a propeller exhaust
passageway having a discharge opening with a diameter
substantially the same as the given diameter of the
outlet, and an inlet located rearwardly of the lower
unit exhaust passageway outlet and in communication
therewith, which outer hub includes a blade
supporting portion, and a portion located forwardly
3~ 67363-725
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of the blade supporting portion and extending,
relative to the blade supporting por-tion, radially
outwardly in spaced relation to the outer surface of
the gearcase to define a forwardly facing annular
opening located radially outwardly of the outer
surface o~ the gearcase and for admitting water into
the inlet of said propeller exhaust passageway during
forward movement of the prop-llsion device, and a
plurality of blades having radially inner ends
connected to the blade supporting portion of the
outer hub~
In one embodiment, the hub is generally
cylindrical, and the member is on the hub and is
generally annular.
One of the principal Eeatures of the
invention is the provision of a marine propeller
which provides for propeller blade operation in
essentially "solid" water in both a forward thrust
direction and a reverse thrust direction by
preventing exhaust gases from mixing with water
around the propeller blades.
Another of the principal features of
the invention is the provision of a marine propulsion
device with a marine propeller which is simpler and
less expensive to manufacture than some prior marine
propellers and which provides for improved operation
in both forward and reverse thrust directions.
The invention also provides a propeller
for a marine propulsion device including a lower unit
rotatably suppor-ting a propeller shaft for rotation
and including an outer surface and an interior lower
unit exhaust passageway located around the propeller
shaft and having an outlet, which propeller is
adapted to be submerged in water during normal
operation and includes an inner hub adapted to be
connected to the propeller shaft, and an outer hub
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supporting a plurality of blades and connected to arlcl
spaced from the inner hub and defining a propeller
exhaust passageway having an inlet located rearwardly
of the lower unit exhaust passageway outlet and in
communication therewith, which outer hub includes a
portion extending forwardly of the propeller exhaust
passageway inlet and adapted to be located radially
outwardly of and in spaced relation to the lower unit
outer surface to define therebetween a forwardly
facing opening located radially outwardly of the
lower unit outer surface and for admitting water into
the inlet of the propeller exhaust passageway during
forward movement of the propulsion device.
The invention also provides a propeller
for a marine propulsion device including a lower unit
having a gearcase rotatably supporting a propeller
shaft and including a rearward end, and an outer
surface which extends forwardly from the rearward
end, which gearcase also includes an internal exhaust
passageway loca-ted around the propeller shaft and
having, at the gearcase rearward end, an exhaust gas
outlet having a diameter, which propeller includes an
inner hub adapted to be connected to the propeller
shaft, and an outer hub connected to and radially
spaced from the inner hub and defining therebetween a
propeller exhaust passageway having a discharge
opening with a diameter substanti.ally the same as the
given diameter of the outlet, and an inlet located
rearwardly of the exhaust passageway outlet and in
communicat.ion therewith, which outer hub includes a
blade supporting portion, and a portion located
forwardly of the blade supporting portion and
extending radially outwardly relakive to the blade
supporting portion so as to be located in radially
outwardly and spaced relation to the outer surface of
the gearcase to define a forwardly facing opening
~2~ 5~ 67363-725
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located radially outwardly of the outer surface of
the gearcase and for admitting water into the inlet
of the propeller exhaust passageway during forward
movement of the propulsion device, and a plurality of
blades having radially inner ends connected to the
blade supporting portion of t:he outer hub.
The invention also provides a marine
propulsion device including a lower unit adapted to
be submerged in water and comprising a propeller
shaft, a gearcase which supports the propeller shaft
Eor rotation about an axis and which includes a
rearward end, and an outer sur~ace which extends
forwardly from the rearward end, which gearcase also
includes an internal exhaust passageway having, at
the gearcase rearward end, an exhaust gas outlet, and
a propeller including an inner hub connected to the
propeller shaft, and an outer hub connected to and
radially spaced from the inner hub and defining
therebetween a propeller exhaust passageway having an
inlet located rearwardly of the lower unit exhaust
passageway outlet and in communication therewith,
which outer hub includes a orward portion extending
radially outwardly in spaced relation to the outer
surface of the gearcase to define a forwardly facing
annular opening located radially outwardly of the
outer surface of the gearcase and for admitting water
into the inlet of the propeller exhaust passageway
during forward movement of the propulsion device, and
a plurali-ty of blades having radially inner ends
connected to the outer hub.
The invention also provides a marine
propulsion device including a lower unit adapted to
be submerged in water and comprising a propeller
shaft, a gearcase which supports the propeller shaft
Eor rotation about an axis and which includes a
rearward end, and an outer surface which extends
~5~d 3q3 67363-725
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forwardly from the rearward end, which gearcase also
includes an internal exhaust passageway having, at
the gearcase rearward end, an exhaust gas outlet, and
a propeller including an inner hub connected to the
propeller shaft, and an outer hub connected to and
radially spaced from the inner hub and defining
therebetween a propeller exhaust passageway having an
inlet located rearwardly of the lower unit exhaust
passageway outlet and in communication therewi-th,
which outer hub includes a blade supporting portion,
10 and a portion located forwardly of the blade
supporting portion and extending, relative to the
blade supporting portion, radially outwardly in
spaced relation to the outer surface of the gearcase
to define a forwardly Eacing annular opening located
15 radially outwardly of the outer surface of the
gearcase and for admitting water into the inlet of
the propeller exhaust passageway during forward
movement of the propulsion device, and a plurality of
blades having radially inner ends connected to the
20 blade supporting portion of the outer hub.
The invention also provides a propeller
for a marine propulsion device including a lower unit
having a gearcase rotatably supporting a propeller
shaft and including a rearward end~ and an outer
25 surface which extends forwardly from the rearward
end, which gearcase also includes an internal exhaust
passageway located around the propeller shaft and
having, at the gearcase rearward end, an exhaust gas
outlet, the propeller including an inner hub adapted
30 to be connected to the propeller shaft, and an outer
hub connected to and radially spaced from the inner
hub and deEining therebetween a propeller exhaust
passageway having an inlet located rearwardly of the
exhaust passageway outlet and in communication
35 therewith, which outer hub includes a ~orward portion
~ 3~ 67363-725
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extending radially outwardly so as to be located in
radially outwardly and spaced relation to the outer
surEace vf the gearcase to deEine a forwardly facing
opening located radially outwardly of the outer
surface of the gearcase and for admitting water into
the inlet of the propeller e:xhaust passageway during
forward movement of the propulsion device, and a
plurality of blades having radially inner ends
connected to the outer hub.
The invention also provides a propeller
for a marine propulsion device including a lower unit
having a gearcase rotatahly supporting a propeller
shaft and including a rearward end, and an outer
surface which extends forwardly from the rearward
end, which gearcase also includes an internal exhaust
passageway located around the propeller shaft and
having, at the gearcase rearward end, an exhaust gas
outlet, which propeller includes an inner hub adapted
to be connected to the propeller shaft/ and an outer
hub connected to and radially spaced from the inner
hub and defining therebetween a propeller exhaust
passageway having an inlet located rearwardly of the
exhaust passageway outlet and in communication
therewith, which outer hub includes a blade
supporting portion, and a portion located forwardly
of the blade supporting portion and extending
radially outwardly so as to be located in radially
outwardly relation to the blade supporting portion
and to the outer surface of the gearcase and Eor
admitting water into the inlet of the propeller
exhaust passageway during forward movement of the
propulsion device, and a plurality of blades having
radially inner ends connected to the blade supporting
portion of the outer hub.
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Other features and advantages of the
invention will become apparent upon reviewing the
following description. the drawings and the appended
claim6.
BRIEF DESCRIPTION OF THE DRA~INGS
Fig. 1 is a schematic side
representation of 3 marins propulsion device which
embodies varlous of the features of the invention.
Fig. 2 i8 an enlarged side view,
partially broken away, of the marine propeller and
part of the lower unit of the marine propulsion
device illustrated in Fig 1. The propellec
illustrated is shown providing forward thrust.
Fig. 3 is a view similar to Fig. 2 only
illustrating the operation of the propeller when
providing revQrse thrust.
Fig. 4 i6 a cross-sectional viaw of the
marine propeller and propeller shaft ta~en along the
line 4-4 in Fig. 3.
Fig. 5 is a partial view similar to
Fig. 2 of another embodiment o~ the invention.
Fig. 6 is a partial view similar to
Fig. 2 of still another embodiment of the invention.
Before explaininq the invention in
datail, it is to be understood that the invention is
not limited in its application to the details of
cons~euction and ths arrangement of co~ponents set
forth in the following description oc illustrated in
the drawings. The invention is capable of other
embodiments and of being practiced or carried out in
various ways. It is also to be undecstood that the
phraseology or terminology employed herein i6 for the
purpose of description and not of limitation.
~L2~ 3~
DESCRIPTIOM OF THE PREFE~ED EMBODIMENT
Shown in the drawings i8 a marine
propulsion device 10 in the form of an outboard
motor. In other embodiments (not shown), the marine
propulsion device 10 can be a stern dcive unit.
As illu~trated in Fig. 1, the marine
propulsion device 10 includes a lower unit 14 which
is vertically swingable and horizontally staerable.
The lower unit 14 includes a portion 18 which i5
normally submerged in water and which includes a
rearwardly facing exhaust gas discharge opening or
outlet 22 (see Fig. 2). Rotatably supported by the
lower unit portion 18 is a propeller shaft 26 which
includes a rearward portion 30 extending through the
lower unit exhaus~ gas discharge outlet 22 and
rearwardly of the lower unit 14.
The marine propulsion device 10 also
includes suitable maans for rotatably driving the
propeller shaft 26, which means includes a vertically
extending drive shaft 34, an engine 38 operable to
rotate the drive shaf~ 34, and a reversing
transmission 42 connecting the drive shaft 34 to the
propeller shaft 26. The lower unit 14 also includes
an exhaust gas passageway 46 which communicates the
lower unit exhaust outlet 22 with exhaust por~s (not
shown) of the engina 38.
Carried on the propeller shaft 26 for
rotary movement in common therewith is a pcopeller 50
which rotates abouS an axis defined by ~he pro~eller
shaft 26. The propeller 50 includes an inner sleeve
54 adapted to be connected to the propeller shaft 26,
and an inner hub 58 concentric with and spaced from
the inner sleeve 54. An annular thrust bearing 60 i8
~2~3~
located between the innar sleeve 54 and inner hub 58
and on a chamfer on the propeller shaft 26.
The propeller 50 also includes an outer
hub 62 defining a propeller exhaust passageway 66
having an inlet 70 in communication with the lower
unit exhaust passageway outlet 22, and an outlet 74
at the rearward end of the outer hub 62. The
propeller 50 also includes a plurality of blades 7a
extending from the outer hub 62 reacwardly of tha
1~ inlet 70.
More particularly, the propeller shaft
rearward end is splined, and the inner sleeve 54
includes a splined recess ~2 which receives the end
of the propeller shaft 26. Means in the form o~ a
rear washer 84, bolt 86 and a nut 90 arrangement is
provided for attaching the inner sleeve 54 and inner
hub 58 to the propeller shaft 26. A resilient
bushing 94 is captured between the inner sleeve 54
and the inner hub 58 and acts as a slip clutch. The
outer hub 62 is connected to the inner hub 58, as
illustrated in Figs. 2, 3 and 4, by a plurality of
radially extending vanes ~8.
While various constructions can be used
in othec embodimenes, the marine pcopeller 50 also
includes an opening 100 adjacent the lower unit
exhauæt outlet 22 for communicating the lower unit
exhaust passageway 46 with water outside of the outer
hub 62. More particularly, in the illustrated
embodiment, the opening 100 is provided by spacing
the outer hub 62 from the lower unit 14 so as to
allow exhaust gases present at the lower unit exhaust
outlet 22 to communicate with water outside of the
outer hub 62.
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673~3-725
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T~e propeller 50 also includas a membec
104 whieh is located adjacent and rearwacd of tha
opening 100, and whieh extend~ forwardly and radially
outwardly with re peet to the propellec shaft 26.
More particularly, while other con6tcuctions can be
employed in other embodiment~, the member 104 i8 on
the oUcer hub 62 and extends curvilinaarly forwardly
and r~dially outwardly with raspeet to the propeller
shaft 26. Even more partieularly, the member 104 i6
coneave when viewed from the prop~ller 6haft 26
forward of the ~ember 104.
In the illu6trated embodiment, the
inner hub 58 and the outer hub 62 are genecally
eylindrical. The member 104 i8 generally annular and
at lea~t partially de~ines the opening 100
eommunieating the lower unit exhaust pa6sagaway 46
with water outside of the outer hub 62. While othec
eon6truction6 can be employed in other ambodiments, a
portion 108 of the low~r unit portion 18 is received
radially inwardly of the member 104.
Although other con6truction6 can be
used in other embodiments, the membec 104 is a
plastic piece which i6 force fitted on the outer hub
62. In other e~bodiments (noe shown~, the member 104
can b~ a pact of the outec hub 62 and can be cast as
an integral piece of the outar hub 62.
If desired, a diverter ring 112 can be
employed at the rear of the ou~er hub 62, a~
ganerally diselosed in U.S. Stcang Patsnt 3,356,151,
issued December 5, 1967.
In operation, the marine pcopaller 50
provide6 thrust in essentially "solid" water in both
a forward thru6t direetion and a reversa thrust
direetion. In the focward thrust direction, a8
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illustrated in Fig. 2, exhaust gases exiting the
lower unit exhaust outlet 2Z enter into the propeller
exhaust inlet 70. The exhaust gases then pass
through the pcopallee exhaust passageway 66 and exit
out the propeller exhau~t outlet 74. The diverter
ring 112 helps prevent the exhaust gases exiting the
propeller exhaust outlat 74 from mingling with water
around the propeller blades 7a. Furthec, the exhaust
gases are generally prevented feom exiting through
the opening 100 between the outer hub 62 and the
lower unit 14 by the member 104. The membec 104
scoops water into the opening 100 as the propellec 50
moves through the water in the forward direction, and
tha water scooped by the member 104 prevents the
exhaust gases from escaping through the opening 100,
thereby keeping the gases in the pcopeller exhaust
passageway 66 so the gases exit through the propeller
exhaust outlet 74. As a result, the propeller blades
78 opecate in essentially "solid" watec in the
focwacd thrust dicection.
In oparation in the reverse thrust
direction, as illustrated in Fig. 3, gases fcom the
lower unit exhaust outlet 22 exit through the opening
100 pcovided bseween the outer hub 62 and the lower
unit 14. Watec entecing into the propellec exhaust
passageway 66 thcough the pcopeller exhaust outlet 74
assists in forcinq the exhaust gases out thcough the
opening 100. The annular membec 104 diverts away
~rom the propeller blades 78 the exhaust gases
passing through the opening 100 to prevent the
exhaust gases fcom mixing with the watec around the
pcopeller blades 78. As a result, the propeller
blades 78 operate in essentially "solid" water in the
reverse thrust direction.
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Alternate embodiments o~ the marine
propulsion dsvice are illustrated in Figs. 5 and 6,
The alternate embodiments are identical to the first
embodiment except to the extlent differences are
indicated.
In the embodimlent illustrated in Fig.
5, the opening 100 comprises a plurality o~ spaced
openings 140 in communication with the propeller
exhaust passageway 66 and located around the
circumference of the outer hub 62 and forward of the
propeller blades 78. And the forward poetion of the
outer hub 62 is located radially inwardly and in
contact with the lower unit portion 108. In this
embodiment, an annular member 144 is on the outer hub
62 and is located adjacent and rearwardly of the
plurality of openings 140.
In the embodiment illustrated in Fig.
~, the opening 100 comprises a plurality of spaced
openings 150 in communication with the lower unit
exhaust passageway 46 and located around the
circumference of the lower unit gsnerally cylindrical
rearward portion lOa forming the lower unit exhaust
outlet Z2. In this embodiment, an annular member 154
is on the lower unit portion 10~ and is located
adjacent and rearward of the plurality of openings
150. In another embodiment (not shown) the plurality
of openings 150 can be closer to the pcopeller outer
hub 62 and the member 154 can be located on the
propeller outer hub 62 adjacent and rearward of the
plurality of openings 150.
Various of the features of the
invention are set forth in the following claims.
