Marine propulsion – Jet drive
Reexamination Certificate
2002-08-15
2003-12-09
Morano, S. Joseph (Department: 3617)
Marine propulsion
Jet drive
C440S08800J
Reexamination Certificate
active
06659816
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a water jet propeller used in ships and, more particularly, to a structure of a water intake port thereof.
2. Description of Background Art
Japanese Patent Laid-open No. Hei 10-119883 discloses a conventional water jet propeller.
FIGS.
6
(
a
) to
6
(
c
) illustrate the water jet propeller, with FIG.
6
(
a
) being a cross-sectional view, FIG.
6
(
b
) being an enlarged cross-sectional view taken along line b—b in FIG.
6
(
a
), and FIG.
6
(
c
) being a cross-sectional view taken along line c—c in FIG.
6
(
a
).
The water jet propeller is mounted to a rear portion of a ship body
1
. There is provided a water intake port
5
provided with a filter
4
in a side wall of a stator
3
, in which an impeller
2
is rotatably disposed.
The impeller
2
is coupled to a drive shaft
6
, a front portion of which is coupled to an output shaft of an engine not shown. When the impeller
2
is rotatably driven by the engine and spurts of a stream of water are sent through a nozzle
3
a
of the stator
3
to propel the ship body
1
.
As shown in FIG.
6
(
b
), the water intake port
5
is opened in a substantially rectangular shape. A substantially rectangular filter
4
is then mounted in this opening which, in turn, is covered with a lid member
7
which also is of a substantially rectangular shape.
The lid member
7
is provided integrally with a pipe section
7
a
that communicates with the water intake port
5
. A flexible hose
9
is connected by way of a connection pipe
8
to the pipe section
7
a
. An end portion not shown of the flexible hose
9
is, in turn, connected to the engine.
When the impeller
2
is rotatably driven, therefore, part of a water stream on a downstream side thereof is supplied from the water intake port
5
to the engine by way of the filter
4
and further through the pipe section
7
a
of the lid member
7
, the connection pipe
8
, and the flexible hose
9
, thus being used as engine coolant.
Referring to FIGS.
6
(
b
) and
6
(
c
), the filter
4
is provided with a flange
4
b,
while the lid member
7
is also provided with a flange
7
b
. The filter
4
and the lid member
7
are jointly fastened together using four bolts
7
c
with the flanges
4
b
,
7
b
mated to each other. Thus, the filter
4
and the lid member
7
are removably mounted with respect to the side portion of the stator
3
.
According to the conventional water jet propeller described in the foregoing paragraphs, the filter
4
and the lid member
7
of the water intake port
5
are shaped into a substantially rectangle, and they are mounted to the stator
3
by jointly fastening them together using four bolts
7
c
with the flanges
4
b
,
7
b
mated to each other. This makes the mounting job extremely laborious.
SUMMARY AND OBJECTS OF THE INVENTION
It is therefore an object of the present invention to solve this problem and to provide a water jet propeller that allows a filter and a lid to be mounted with ease.
To achieve the foregoing object, according to the present invention, there is provided a water jet propeller wherein a water intake port includes a filter that is provided in a side wall of a stator containing a rotatable impeller, wherein the side wall of the stator is provided with a tubular filter accommodation chamber that forms the water intake port. A tubular filter is housed in the filter accommodation chamber and an opening is formed in a circular shape in the filter accommodation chamber and is closed by a circular lid through tightening screws or press-fitting.
According to the present invention, a flow path is integrally formed with respect to a peripheral wall of the filter accommodation chamber and a bottom portion of the tubular filter is formed by an inclined surface that is inclined with respect to an axial direction of the tubular filter. In addition, an inclined step portion is formed in the filter accommodation chamber so as to abut against and receive an edge portion of the inclined surface of the tubular filter. An opening, which communicates with the flow path when the inclined surface edge portion abuts against the inclined step portion so that the two portions are brought into coincidence with each other, is formed in the tubular filter.
According to the present invention, a flow path is integrally formed with respect to a peripheral wall of the filter accommodation chamber. An inner peripheral surface of the filter accommodation chamber and an outer peripheral surface of the tubular filter are partially formed into a flat surface. An opening, which communicates with the flow path when the flat surface portion of the tubular filter coincides with the flat surface portion of the filter accommodation chamber, is formed in the tubular filter.
In the water jet propeller according to the present invention, the water intake port that includes the filter is provided in the side wall of the stator containing the rotatable impeller. The tubular filter accommodation chamber forming the water intake port is provided in the side wall of the stator. The tubular filter is housed in the filter accommodation chamber with the circular opening formed in the filter accommodation chamber. The circular lid is either screwed or press-fitted in position to close the circular opening. According to the water jet propeller having this arrangement, the filter and the lid can be mounted to the side wall of the stator by simply closing the opening in the filter accommodation chamber through either screwing or press-fitting, after the tubular filter has been placed in the tubular filter accommodation chamber.
Namely, in the water jet propeller according to the present invention, it is remarkably easier to mount the filter and the lid than in the conventional arrangement.
According to the water jet propeller of the present invention, the flow path is integrally formed with respect to the peripheral wall of the filter accommodation chamber and the bottom portion of the tubular filter is formed by the inclined surface that is inclined with respect to the axial direction of the tubular filter, the inclined step portion is formed in the filter accommodation chamber so as to abut against and receive the edge portion of the inclined surface of the tubular filter. The opening, which communicates with the flow path when the inclined surface edge portion abuts against the inclined step portion so that the two portions are brought into coincidence with each other, is formed in the tubular filter. All this offers the following function.
Namely, in the conventional water jet propeller described earlier, the flow path from the filter accommodation chamber is formed by the pipe section
7
a
that is integrated with the lid member
7
. Therefore, if the lid member
7
is mounted in a reverse direction with respect to a fore-and-aft direction, the flow path
7
a
is also mounted in a reverse direction with respect to the fore-and-aft direction. More attention should therefore be paid to the mounting of the lid member
7
, thus making the mounting job even more laborious.
According to the water jet propeller of the present invention, on the other hand, the problems inherent in the conventional technology will not occur, since the flow path is formed integrally with respect to the peripheral wall of the filter accommodation chamber.
In addition, the bottom portion of the tubular filter is formed by the inclined surface that is inclined with respect to the axial direction of the tubular filter, the inclined step portion is formed in the filter accommodation chamber so as to abut against and receive the edge portion of the inclined surface of the tubular filter. In view of the opening, which communicates with the flow path when the inclined surface edge portion abuts against the inclined step portion so that the two portions are brought into coincidence with each other, formed in the tubular filter, the flow path in the filter accommodation chamber and the opening in the filter are automatically brought into comm
Honda Gikden Kogyo Kabushiki Kaisha
Morano S. Joseph
Olson Lars A.
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