Note: Descriptions are shown in the official language in which they were submitted.
9~i
l BOW PROPELLER UNIT
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EU~CKGROUND OF 'rHE lNVEllTIOI~
The present invention`relates to a bow propeller
unit for maneuvering of water crafts.
Bow propeller units for maneuvering of water
craft are known and widely utilized. A known bow propeller
unit has an approximately cylindrical drive housing extending
in a transverse passage provided in a bow below a waterline
and having two open ends, a propeller arranged substantially
in a radial central plane of the transverse passage so that
a drive unit is substantially symmetrical to the radial
central plane, and two guide blade rings are arranged at both
sides of the propeller with one guide blade ring fixedly con-
necting a bearing housing for a propeller hub with the drive
~ 15 housing, wherein a driving medium is supplied for driving
;~ the propeller via an opening which is formed in the drive
housing and open into a hollow guide blade.
The bow propeller unit of the above-mentioned type
is disclosed for example in the German Auslegeschrift
1,123,939. The hub of the propeller in this construction is
supported at both sides, and both bearing housings are
fixedly connected via the respective guide blade ring with
the drive housing. The drive housing is inserted into the
transverse passage with roughly constant diameter and rests
there with its two ends on supporting rings and secured
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again~t a al displacemen~ by rings arranged at end sides.
The latter mentioned rings can be removed for dismounting of
the bow propeller unit. Both guide blade rings have a
rounded hub in alignment with the cylindrical hub of
the propeller. The bow propeller unit is formed`mirror-
symmetrical relative to a radial plane extending through the
c,entrally arranged propeller. The drive of the propeller is
formed by an electric motor arranged outside of the
transverse passage and having a vertical drive shaft which
extends through an opening in the periphery of the drive hous-
ing and through the hollow guide blade connected therewith
so as to drive the propeller hub via a conical gear trans-
mission arranged in a bearing housing of the propeller hub;
This construction possesses the disadvantage that
the drive motor is located outside of the transverse passage.
Since the space above or below the transverse passage is not
sufficient for accommodating the drive means or is occupied
by other parts of the ship, such as chain lockers, ballast
tanks, and the like, the transverse passage cannot be
arranged in the considerably reduced part of the ship's bow,
but must be somewhat displaced more to the center of the
ship. The action of a bow propeller with given drive current
increases with increase of the distance of the transverse
passage from the turning point in the ship's center toward
a bow or stern of the ship. Thereby a small axial length of
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1 the transverse passage is provided, which is ver~v advantage-
ous, inasmuch as the transverse passage can be arranged rela-
tively deep below the waterline of the ship. Such an
arrangement reduces, because of the high water pressure, the
danger of cavitation and makes possible higher peripheral
speed and thereby also higher thrust power with given struc-
~ural dimensions. The above-mentioned desired small a~ial
length o the transverse passage cannot be obtained in the
construction disclosed in the German Auslegeschrift
1,123,939 not only because the drive motor is arranged outside
of the transverse passage, but also because tXe great axial
length of the bow propeller unit. This great axial length
is first of all reguired because of the two-sided support of
the propeller hub and the thereby produced relatively great
axial distance of both guide blade rings from the propeller.
Another bow propeller unit is proposed in the
German patent 1,456,282 with a relatively shorter axial
length of the unit, wherein the propeller lies in the radial
central plane of the transverse passage of a bulbous bow of
a ship. The propeller hub forms a rotor of an electrical
submerged motor formed as an external rotor motor and is
supported at both its ends in hoods located symmetrically
to the radial central plane. Because of this support, the
bow propeller unit is always relatively long. The disadvan-
tage of this construction is a very expensive drive. More-
~O~il
over, no guide blade rings are provided in this con-
struction, so that the bow propeller unit possesses
additional disadvantages in the sense of flow action.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present inven-
tion to provide a bow propeller unit which avoids the
disadvantages of the prior art.
More particularly, it is an object of the present
invention to provide a bow propeller unit which is axially
shorter and can be arranged in a transverse passage with
the respectively smaller axial length than in the case of
the known bow propeller units.
According to the invention there is provided a bow
propeller unit for maneuvering of a water craft having a
transverse passage extending in a bow below a waterline
and having a radial central plane and two open ends, the
bow propeller unit comprising a drive housing arranged in
the transverse passage; a propeller arranged substantially
in the radial central plane of the transverse passage and
having a hub and an axis extending in the direction of the
transverse passage; two guide blade elements arranged at
opposite axial ends of said propeller; a bearing housing
for said hub of said propeller and being fixedly connected
with said drive housing by one of said guide blade
elements; means for supplying a driving medium to said
propeller and including one hollow guide blade provided
on one of said guide blade elements and an opening pro-
vided in said drive housing and communicating with said
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one hollow blade; and a drive motor for said propeller
supplied with the driving medium, said hub of said
propeller being supported in a overhung manner and formed
as a one-sided open bush surrounding said drive motor and
having a bottom, said drive motor having a drive shaft
fixedly connected with said bottom of said bush, and
said guide blade elements being axially closely arranged
adjacent said propeller.
It is important for the short axial length of the
bow propeller unit in accordance with the invention that
the propeller unit have a overhung support. Since the
propeller hub, moreover, completely overlaps the drive
motor, the
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l mirror-symmetrical construction of the bow propeller unit
relative to the propeller can be maintained despite the
one-sided support. This is of great importance for bow
propellers controllable in their rotation directions.
Because of the inventive support, it is further possible to
arrange both guide plate rings closel~ aajacent to the
p,ropeller so as to obtain a further shortening of the axial
length. Since the drive motor in the inventive construction
is located inside the propeller hub and not outside of the
transverse passage, the short length of the inventive drive
aggregate can be completely utilized by selection of a
respectively short transverse passage which does not require
any appreciable mounting space above or below the transverse
passage.
In accordance with another particularly advantage-
ous feature of the present invention, the drive motor may be
; formed as a hydraulic motor, and hydraulic conduits for the
hydraulic motor may extend through the hollow guide plate.
Suitable conduit coupling means can be provided in the
20~ hydraulic conduits so that the bow propeller unit can be
easily mounted or dismounted.
In accordance with still another advantageous
feature of the present invention, the hollow guide blade
can be provided with a removable cover which allows an
access to the open end of the propeller hub formed as the
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1 bush and thereby allows a simple dismounting of the drive
motor and a simple inspection of the hydraulic conduits.
In order to further reduce the axial length of
the drive aggregate, it is advantageous when the guide blades
S are slanted axially inwardly and have an inner contour which
is approximately parallel to the outer contour o~ the blades
of the propeller. Thereby it is possible that the axial
length of the drive housing substantially corresponds to its
diameter.
An especially simple and reliable construction
is obtained when one of the guide blade rings is formed as a
separate structural element and connected with the drive
housing advantageously detachably by a plug connection. The
transmission of the torque is carried out via the other
guide blade ring, which executes the mechanical connection
between the bearing housing and the drive housing and com-
prises the hollow guide blade.
In order to provide for favorable location of
the bow propeller unit, in the sense of fluid mechanics,
it is advantageous when both guide blade rings have rounded
hubs which are in alignment with the cylindrical propeller
hub. The hub of the guide blade ring formed as a separate
structural element can overlap the connection between the
drive shaft and the propeller hub in an especially advantage-
ous manner. The format1on of the guide blade ring as a
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l ¦separate element allows its removal from the drive housing so~
¦as to provide access to the above-mentioned rotary connec-
¦tion.
l In order to facilitate the mounting and dismount- ¦
¦ing of the bow propeller unit, it is advantageous in accord- ¦ -
ance with a further feature of the present invention to form !
t~e drive housing with a slightly conical outer contour. In
¦such a construction, during insertion of the drive unit into
¦¦the transverse passage or re~oval from the latter, tilting
¦lor clamping is prevented.
¦ The novel features which are considered charac-
¦teristic for the invention are set forth in particular in
¦the appended claims. The invention itself, however, both as
lto its construction and its method of operation, togethex
lwith additional objects and advantages thereof, will be best
¦~understood from the following description of specific embodi-
~ments when read in connection with the accompanying drawing.
jl BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a view showing a longitudinal section
¦lof a bow propeller unit in accordance with the present in-
¦¦Yention; and
FIG.2 is a view showing a section taken along th
~line 2-2 in FIG. 2, wherein a propeller is turned relative
¦¦to the view of FIG. 1 by 45 for the sake of clarity.
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DESCRIPTION OF TH~ PREFERRED EM13ODIMENTS
A bow propeller unit in accordance with the pre-
sent invention is provided for a water craft having a bow
wall which is identified by reference numeral 1. A trans-
verse passage 2 extends transverse to the longitudinal axis
of the water craft in the bow region below the waterline and
is open at both its sides. The bow propeller unit is ~
arranged in this transverse passage 2.
The bow propeller unit includes a drive housing 3
which has a somewhat conical outer contour, and a propeller
4 which is surrounded by the drive housing 3. The propeller
4 is located substantially in the radial center plane of the
¦transverse passage 2. The entire bow propeller unit is
~ mirror-symmetrical relative to the above-mentioned radial
;~ 15 central plane. The drive housing 3 is secured against rota-
: tion in the transverse passage 2 by a pin 5 or the like.
The propeller 4 has a hub 6 which is formed as a
bush with one open end. The hub or bush 6 completely sur-
rounds a drive motor 7 which advantageously is formed as a
~; 20 hydraulic motor. The drive motor 7 has a drive shaft 8
which is connected with the bottom 6a of the bush-shaped hub
6 for joint rotation therewith.
The drive motor 7 is firmly supported in a bearing
housing 9 which is located concentrically inside the bush-
shaped propeller hub 6. The bearing housing 9 is completely
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1 overlapped by the propeller hub 6 and transit into a
guide blade ring 10. The guide blade ring 10 is connected
with the drive housing 3 for transmission of the torque.
An opening 11 is provided in the outer surface of the drive
¦ housing 3 and opens into a hollow guide blade 12 of the
above-mentloned guide blade ring 10. Hydraulic conduits 13
e~xtend through the hollow guide blade 12 to the drive motor
7. The hollow guide blade 12 has a removable cover 14 which
closes the open end of the bearing housing 9 from outside.
A guide blade ring 15 is provided at the right end
of the propeller 4, as seen in FIG. 1. The guide blade ring
15 is formed as a separate structural element and is
detachably connected with the drive housing 3 via a plug
connection 16. Both guide plate rings 10 and 15 have a
rounded hub 17 which is in alignment with the cylindrical
propeller hub 6. Moreover, the guide blades of both guide
blade rings 10 and 15 are inwardly slanted and extend with
their inner contour 18 approximately parallel to an outer
contour 19 of the blades of the propeller 4.
The drive motor 7 is connected at its end side
with the bearing housing 9 by a bolt. A shaft sealing member
20 is further provided, and arranged so as to prevent pene-
tration of water into the motor 7 or into the bearing hous-
ing 9.
It will be understood that each of the elements
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l described above, or two or more together, may also find a
useful application in other types of constructions differing
from the types described above.
While the invention has been illustrated and de-
scribed as embodied in a bow propeller unit, it is not
intended to be limited to the details shown, since various
~odifications and structural changes may be made without
departing in any way from the spirit of the present inven-
tion. .
Without further analysis, the foregoing will so
fully reveal the gist of the present invention that others
can, by applying current knowledge,readily adapt it for
~arious applications without omitting features that, from
the standpoint of prior art, fairly constitute essential
: 15 characteristics of the generic or specific aspects of this
invention.
What is claimed as new and desired to be pro-
: tected by Letters Patent is set forth in the appended
~ claims:
