CA2395728C - Water jet propulsion apparatus - Google Patents
Water jet propulsion apparatus Download PDFInfo
- Publication number
- CA2395728C CA2395728C CA002395728A CA2395728A CA2395728C CA 2395728 C CA2395728 C CA 2395728C CA 002395728 A CA002395728 A CA 002395728A CA 2395728 A CA2395728 A CA 2395728A CA 2395728 C CA2395728 C CA 2395728C
- Authority
- CA
- Canada
- Prior art keywords
- cap
- duct
- bearing
- impeller
- jet propulsion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 33
- 238000003780 insertion Methods 0.000 description 5
- 230000037431 insertion Effects 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63H—MARINE PROPULSION OR STEERING
- B63H11/00—Marine propulsion by water jets
- B63H11/02—Marine propulsion by water jets the propulsive medium being ambient water
- B63H11/10—Marine propulsion by water jets the propulsive medium being ambient water having means for deflecting jet or influencing cross-section thereof
- B63H11/103—Marine propulsion by water jets the propulsive medium being ambient water having means for deflecting jet or influencing cross-section thereof having means to increase efficiency of propulsive fluid, e.g. discharge pipe provided with means to improve the fluid flow
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63H—MARINE PROPULSION OR STEERING
- B63H11/00—Marine propulsion by water jets
- B63H11/02—Marine propulsion by water jets the propulsive medium being ambient water
- B63H11/04—Marine propulsion by water jets the propulsive medium being ambient water by means of pumps
- B63H11/08—Marine propulsion by water jets the propulsive medium being ambient water by means of pumps of rotary type
Abstract
To sufficiently reduce a rotation component of a water stream very close to the external face of a cap 34 of a bearing, reduce the size of the cap 34, and make positioning between the cap 34 and another stationary vane 31c1 unnecessary. In a water jet propulsion apparatus having a duct 31 forming a channel, an impeller 32 disposed in the duct 31, a bearing 33 of the impeller 32 provided in the duct 31, and a cap 34 closing the rear end of the bearing 33, stream straightening grooves 34a are formed in the external face of the cap 34. In a portion facing the cap 34, in the internal face of the duct 31, a stationary vane 31c1 is formed toward the cap 34.
Description
W ATER JET PROPULSION APPARATUS
FIELD OF THE INVENTION
The present invention relates to a water jet propulsion apparatus for use in a boat.
BACKGROUND OF THE INVENTION
A known conventional water jet propulsion apparatus is as shown in FIG.
6 (Japanese Patent Laid-open No. Hei-5-105189).
The water jet propulsion apparatus has a duct 2 forming a channel communicated with an intake 1a provided on the bottom of a hull 1, an impeller 3 disposed in the duct 2, a bearing 4 of the impeller provided i n the duct 2, and a cap 5 closing the rear end of the bearing 4.
The duct 2 is constructed by an impeller duct 2a, a stationary vane duct 2b, and a nozzle 2c, and the bearing 4 is formed integrally with the stationary vane duct 2b via a stationary vane 2b1 in the stationary vane duct 2b.
The impeller 3 is fixed to a drive shaft 6. The front end of the drive shaft 6 is coupled to the output shaft of a not-illustrated engine mounted on the hull 1, and the rear end 6a is rotatably supported by the bearing 4.
JJ-11737/cs A stationary vane 5a is formed on the external face of the cap 5, and a stationary vane 2c1 is integrally formed also on the internal face of the nozzle 2c.
A deflector 7 is rotatably attached to the rear part of the nozzle 2c.
In such a water jet propulsion apparatus, when the impeller 3 is rotated by the rotation of the engine via the drive shaft 6, water taken from the intake 1a is passed through the impeller duct 2a and injected from a jet port 2c2 of the nozzle 2c to the outside via the deflector 7 while being straightened up by the stationary vanes 2b1 and 2c1 in a process of passing through the stationary duct 2b and nozzle 2c, thereby propelling the hull 1.
In the above-described conventional water jet propulsion apparatus, since the stationary vane 5a is formed on the cap 5, the rotation component of a water stream near the center of the nozzle 2c, that is, around the cap 5 can be reduced (the stream can be straightened) to a certain degree. However, it is difficult to form a number of stationary vanes 5a in the limited length of the outer circumference of the cap 5 whose diameter is relatively small, there is a problem such that the rotation component of a water stream very close to the external face of the cap 5 cannot be sufficiently reduced.
Moreover, since the stationary vane 5a is formed on the external face of the cap 5, there is also a problem such that the cap 5 itself including the stationary vane 5a is large.
Further, there is also a problem such that the stationary vane 5a formed on the external face of the cap 5 and the stationary vane 2c1 formed on the JJ-11737~cs internal face of the nozzle 2c have to be positioned.
An object of the invention is to provide a water jet propulsion apparatus which can solve the above problems and sufficiently reduce the rotation component of the water stream very close to the external face of the cap while reducing the size of the cap and, further, which needs no unnecessary positioning between the cap and other stationary vanes.
S~JMMARY OF THE INVENTION
To achieve the object, a water jet propulsion apparatus of the present invention includes a duct forming a channel, an impeller disposed in the duct, a bearing of the impeller provided in the duct, and a cap closing the rear end of the bearing and is characterized in that stream straightening grooves are formed in the external face of the cap.
The water jet propulsion apparatus of an aspect of the invention is characterized in that, in the above water jet propulsion apparatus, a stationary vane is formed toward the cap in a portion facing the cap, in the internal face of the duct.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are shown in the drawings, wherein:
FIG. 1 is a schematic side view showing an example of a small planing boat using an embodiment of a water jet propulsion apparatus according to the invention.
JJ-11737/cs ' -4-FIG. 2 is a plan view of the small planing boat.
FIG. 3 is a cross section mainly showing a water jet propulsion apparatus.
FIG. 4 is a view mainly showing the water jet propulsion apparatus from the back.
FIGS. 5A, 5B, 5C, and 5D are a side view, a right side view (view seen from the back of a boat body), a cross section taken along line c-c of FIG. 5B, and a cross section taken along line d-d of FIG. 5B, respectively, of a cap 34.
FIG. 6 is a diagram for explaining a prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of the invention will be described hereinbelow with reference to the drawings.
FIGS. 1 and 2 are a schematic side view and a plan view, respectively, showing an example of a small planing boat using an embodiment of the water jet propulsion apparatus according to the invention. FIG. 3 is a cross section mainly showing a water jet propulsion apparatus. FIG. 4 is a view mainly showing the water jet propulsion apparatus seen from the back.
As shown in FIGS. 1 and 2, this small planing boat 10 is a saddle-type small boat. An occupant sits on a seat 12 of a boat body 11, and can drive the small planing boat 11 by gripping a steering handle 13 with a throttle lever.
The boat body 11 has a floating body structure obtained by bonding a hull 14 and a deck 15 and forming a space 16 on the inside. In the space 16, an JJ-11737/cs engine 20 is mounted on the hull 14, and a water jet propulsion apparatus (hereinbelow, also called a jet pump) 30 as propulsion means driven by the engine 20 is provided in the rear part of the hull 14.
As also shown in FIG. 3, the jet pump 30 has a duct 31 forming a channel 18 communicated with an intake 17 provided on the bottom of the boat body 11, an impeller 32 disposed in the duct 31, a bearing 33 of the impeller provided in the duct 31, and a cap 34 for closing the rear end of the bearing 33.
The duct 31 has an impeller housing part 31a, a bearing housing part 31b, and a nozzle part 31c. The impeller housing part 31a and the bearing housing part 31b are formed integrally, and the bearing 33 is integrally formed in the bearing housing part 31b via a stationary blade 31b1.
The front part of a boss 32a of the impeller 32 is engaged with a spline 22b formed in the rear end of a drive shaft, so that the impeller 32 rotates with the drive shaft 22. The front end 22a of the drive shaft 22 is coupled to an output shaft 21 (refer to FIG. 1) of the engine 20 mounted on the boat body 11 via a coupler 23.
On the other hand, a supporting shaft 35 for supporting the rear part 32b of the boss 32a of the impeller 32 is rotatably supported by the bearing 33 via a ball bearing 33a. A male screw 35a is formed at the tip of the supporting shaft 35 and is screwed in a female screw formed in the boss rear part 32b of the impeller 32, thereby coupling the impeller 32 and the supporting shaft 35.
JJ-11737/cs Therefore, the front part of the boss 32a of the impeller 32 is coupled to the drive shaft 22, the rear part 32b of the boss is coupled to the supporting shaft 35, and the impeller 32 rotates with the drive shaft 22 and the supporting shaft 35.
FIGS. 5A, 5B, 5C, and 5D are a side view, a right side view (seen from the back of the boat body), a cross section taken along line c-c of FIG. 5B, and a cross section taken along line d-d of FIG. 5B, respectively, of the cap 34.
As obvious from FIG. 5, a plurality of (12 in the diagram) of stream straightening grooves 34a are formed in the external face of the cap 34.
An insertion part (cylindrical part) 34b inserted to the rear part of the bearing 33 is formed in the front part of the cap 34, and three insertion holes 34c for screws 36 (refer to FIG. 3) are formed between the stream straightening grooves 34a. An attachment groove 34b1 for an O ring (not shown) is formed in the cylindrical insertion part 34b.
Therefore, an O ring is attached to the cylindrical insertion part 34b and the insertion part 34b is inserted (force-fit) into the rear part of the bearing 33 as shown in FIG. 3, thereby attaching the cap 34 to the rear part of the bearing 33 by the screws 36.
In the part facing the cap 34 in the internal face of the nozzle 31c, a stationary blade 31c1 is formed toward the cap 34.
In the nozzle part 31c, a bilge pipe 37 for draining bilge water on the bottom of the boat is inserted.
A deflector 38 is turnably attached to the rear part of the nozzle part 31c.
.TT-11737/cs In the jet pump 30 as described above, the impeller 32 is rotated by the rotation of the engine 20 via the drive shaft 22, and water taken from the intake 17 is jetted from a jet port 31c2 of the nozzle part 31c to the outside via the deflector 38 while being straightened by the stationary vanes 31b1 and 31c1 and the stream straightening grooves 34a of the cap 34 in a process of passing through the duct 31, thereby propelling the boat body 11.
The number of revolutions of the engine 20, that is, the propulsion generated by the jet pump 30 is controlled by an operation of turning a throttle lever 13a (refer to FIG. 2) of the steering handle 13. An arm 38a (refer to FIG. 4) of the deflector 38 is linked with the steering handle 13 via a not-illustrated control wire and is turned by the operation of the handle 13, thereby enabling the course to be changed.
Since the water jet propulsion apparatus 30 as described above has the duct 31 forming the channel, the impeller 32 disposed in the duct 31, the bearing 33 of the impeller 32 provided in the duct 31, and the cap 34 closing the rear end of the bearing 33, and the stream straightening grooves 34a are formed in the external face of the cap 34, the rotation component of the water stream very close to the external face of the cap 34 can be reduced by the stream straightening grooves 34a.
Moreover, since it is sufficient to form the stream straightening grooves 34a, not a stream straightening plate (stationary vane) in the external face of the cap 34, a number of stream straightening grooves can be formed by, for example, cutting in the limited outer circumference length of the cap 34 whose diameter is relatively small. Thus, the rotation component of the water stream very close to the external face of the cap 34 can be JJ-11737/cs sufficiently reduced.
Further, since the stream straightening grooves, not a stream straightening plate, are formed in the external face of the cap 34, the size of the cap 34 can be reduced.
Further, since what is formed in the external face of the cap 34 is, not a stream straightening plate but, the stream straightening grooves 34a, it becomes unnecessary to position the cap 34 with the other stationary vanes 31b1 and 31c1.
Therefore, formation of the stream straightening grooves 34a in the external face of the cap 34 is particularly effective in the case where the stationary vane 31c1 is formed toward the portion facing the cap 34, in the internal face of the duct 31 as in the embodiment.
Since what is formed in the external face of the cap 34 are the stream straightening grooves 34a, not a stream straightening plate, n o interference occurs between the cap 34 and the bilge pipe 37.
Since the water jet propulsion apparatus of the present invention includes a duct forming a channel, an impeller disposed in the duct, a bearing of the impeller provided in the duct, and a cap closing the rear end of the bearing, and stream straightening grooves are formed in the external face of the cap. Consequently, a rotation component of a water stream very close to the external face of the cap can be reduced by the stream straightening grooves.
JJ-11737/cs _g_ Moreover, since it is sufficient to form the stream straightening grooves, not a stream straightening plate (stationary vane) in the external face of the cap, a number of stream straightening grooves can be formed in the limited outer circumference length of the cap whose diameter is relatively small. Thus, the rotation component of the water stream very close to the external face of the cap can be sufficiently reduced.
Further, since the stream straightening grooves, not a stream straightening plate, are formed in the external face of the cap, the size of the cap can be reduced.
Further, since what is formed in the external face of the cap is, not a stream straightening plate but, stream straightening grooves, it becomes unnecessary to position the cap with the other stationary vanes.
Therefore, formation of the stream straightening grooves in the external face of the cap is particularly effective in the case where a stationary vane is formed toward the portion facing the cap, in the internal face of the duct as an embodiment of the invention.
Although the embodiment of the invention has been described above, the invention is not limited to the foregoing embodiment but can be properly modified within the range of the gist of the invention.
JJ-11737/cs
FIELD OF THE INVENTION
The present invention relates to a water jet propulsion apparatus for use in a boat.
BACKGROUND OF THE INVENTION
A known conventional water jet propulsion apparatus is as shown in FIG.
6 (Japanese Patent Laid-open No. Hei-5-105189).
The water jet propulsion apparatus has a duct 2 forming a channel communicated with an intake 1a provided on the bottom of a hull 1, an impeller 3 disposed in the duct 2, a bearing 4 of the impeller provided i n the duct 2, and a cap 5 closing the rear end of the bearing 4.
The duct 2 is constructed by an impeller duct 2a, a stationary vane duct 2b, and a nozzle 2c, and the bearing 4 is formed integrally with the stationary vane duct 2b via a stationary vane 2b1 in the stationary vane duct 2b.
The impeller 3 is fixed to a drive shaft 6. The front end of the drive shaft 6 is coupled to the output shaft of a not-illustrated engine mounted on the hull 1, and the rear end 6a is rotatably supported by the bearing 4.
JJ-11737/cs A stationary vane 5a is formed on the external face of the cap 5, and a stationary vane 2c1 is integrally formed also on the internal face of the nozzle 2c.
A deflector 7 is rotatably attached to the rear part of the nozzle 2c.
In such a water jet propulsion apparatus, when the impeller 3 is rotated by the rotation of the engine via the drive shaft 6, water taken from the intake 1a is passed through the impeller duct 2a and injected from a jet port 2c2 of the nozzle 2c to the outside via the deflector 7 while being straightened up by the stationary vanes 2b1 and 2c1 in a process of passing through the stationary duct 2b and nozzle 2c, thereby propelling the hull 1.
In the above-described conventional water jet propulsion apparatus, since the stationary vane 5a is formed on the cap 5, the rotation component of a water stream near the center of the nozzle 2c, that is, around the cap 5 can be reduced (the stream can be straightened) to a certain degree. However, it is difficult to form a number of stationary vanes 5a in the limited length of the outer circumference of the cap 5 whose diameter is relatively small, there is a problem such that the rotation component of a water stream very close to the external face of the cap 5 cannot be sufficiently reduced.
Moreover, since the stationary vane 5a is formed on the external face of the cap 5, there is also a problem such that the cap 5 itself including the stationary vane 5a is large.
Further, there is also a problem such that the stationary vane 5a formed on the external face of the cap 5 and the stationary vane 2c1 formed on the JJ-11737~cs internal face of the nozzle 2c have to be positioned.
An object of the invention is to provide a water jet propulsion apparatus which can solve the above problems and sufficiently reduce the rotation component of the water stream very close to the external face of the cap while reducing the size of the cap and, further, which needs no unnecessary positioning between the cap and other stationary vanes.
S~JMMARY OF THE INVENTION
To achieve the object, a water jet propulsion apparatus of the present invention includes a duct forming a channel, an impeller disposed in the duct, a bearing of the impeller provided in the duct, and a cap closing the rear end of the bearing and is characterized in that stream straightening grooves are formed in the external face of the cap.
The water jet propulsion apparatus of an aspect of the invention is characterized in that, in the above water jet propulsion apparatus, a stationary vane is formed toward the cap in a portion facing the cap, in the internal face of the duct.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are shown in the drawings, wherein:
FIG. 1 is a schematic side view showing an example of a small planing boat using an embodiment of a water jet propulsion apparatus according to the invention.
JJ-11737/cs ' -4-FIG. 2 is a plan view of the small planing boat.
FIG. 3 is a cross section mainly showing a water jet propulsion apparatus.
FIG. 4 is a view mainly showing the water jet propulsion apparatus from the back.
FIGS. 5A, 5B, 5C, and 5D are a side view, a right side view (view seen from the back of a boat body), a cross section taken along line c-c of FIG. 5B, and a cross section taken along line d-d of FIG. 5B, respectively, of a cap 34.
FIG. 6 is a diagram for explaining a prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of the invention will be described hereinbelow with reference to the drawings.
FIGS. 1 and 2 are a schematic side view and a plan view, respectively, showing an example of a small planing boat using an embodiment of the water jet propulsion apparatus according to the invention. FIG. 3 is a cross section mainly showing a water jet propulsion apparatus. FIG. 4 is a view mainly showing the water jet propulsion apparatus seen from the back.
As shown in FIGS. 1 and 2, this small planing boat 10 is a saddle-type small boat. An occupant sits on a seat 12 of a boat body 11, and can drive the small planing boat 11 by gripping a steering handle 13 with a throttle lever.
The boat body 11 has a floating body structure obtained by bonding a hull 14 and a deck 15 and forming a space 16 on the inside. In the space 16, an JJ-11737/cs engine 20 is mounted on the hull 14, and a water jet propulsion apparatus (hereinbelow, also called a jet pump) 30 as propulsion means driven by the engine 20 is provided in the rear part of the hull 14.
As also shown in FIG. 3, the jet pump 30 has a duct 31 forming a channel 18 communicated with an intake 17 provided on the bottom of the boat body 11, an impeller 32 disposed in the duct 31, a bearing 33 of the impeller provided in the duct 31, and a cap 34 for closing the rear end of the bearing 33.
The duct 31 has an impeller housing part 31a, a bearing housing part 31b, and a nozzle part 31c. The impeller housing part 31a and the bearing housing part 31b are formed integrally, and the bearing 33 is integrally formed in the bearing housing part 31b via a stationary blade 31b1.
The front part of a boss 32a of the impeller 32 is engaged with a spline 22b formed in the rear end of a drive shaft, so that the impeller 32 rotates with the drive shaft 22. The front end 22a of the drive shaft 22 is coupled to an output shaft 21 (refer to FIG. 1) of the engine 20 mounted on the boat body 11 via a coupler 23.
On the other hand, a supporting shaft 35 for supporting the rear part 32b of the boss 32a of the impeller 32 is rotatably supported by the bearing 33 via a ball bearing 33a. A male screw 35a is formed at the tip of the supporting shaft 35 and is screwed in a female screw formed in the boss rear part 32b of the impeller 32, thereby coupling the impeller 32 and the supporting shaft 35.
JJ-11737/cs Therefore, the front part of the boss 32a of the impeller 32 is coupled to the drive shaft 22, the rear part 32b of the boss is coupled to the supporting shaft 35, and the impeller 32 rotates with the drive shaft 22 and the supporting shaft 35.
FIGS. 5A, 5B, 5C, and 5D are a side view, a right side view (seen from the back of the boat body), a cross section taken along line c-c of FIG. 5B, and a cross section taken along line d-d of FIG. 5B, respectively, of the cap 34.
As obvious from FIG. 5, a plurality of (12 in the diagram) of stream straightening grooves 34a are formed in the external face of the cap 34.
An insertion part (cylindrical part) 34b inserted to the rear part of the bearing 33 is formed in the front part of the cap 34, and three insertion holes 34c for screws 36 (refer to FIG. 3) are formed between the stream straightening grooves 34a. An attachment groove 34b1 for an O ring (not shown) is formed in the cylindrical insertion part 34b.
Therefore, an O ring is attached to the cylindrical insertion part 34b and the insertion part 34b is inserted (force-fit) into the rear part of the bearing 33 as shown in FIG. 3, thereby attaching the cap 34 to the rear part of the bearing 33 by the screws 36.
In the part facing the cap 34 in the internal face of the nozzle 31c, a stationary blade 31c1 is formed toward the cap 34.
In the nozzle part 31c, a bilge pipe 37 for draining bilge water on the bottom of the boat is inserted.
A deflector 38 is turnably attached to the rear part of the nozzle part 31c.
.TT-11737/cs In the jet pump 30 as described above, the impeller 32 is rotated by the rotation of the engine 20 via the drive shaft 22, and water taken from the intake 17 is jetted from a jet port 31c2 of the nozzle part 31c to the outside via the deflector 38 while being straightened by the stationary vanes 31b1 and 31c1 and the stream straightening grooves 34a of the cap 34 in a process of passing through the duct 31, thereby propelling the boat body 11.
The number of revolutions of the engine 20, that is, the propulsion generated by the jet pump 30 is controlled by an operation of turning a throttle lever 13a (refer to FIG. 2) of the steering handle 13. An arm 38a (refer to FIG. 4) of the deflector 38 is linked with the steering handle 13 via a not-illustrated control wire and is turned by the operation of the handle 13, thereby enabling the course to be changed.
Since the water jet propulsion apparatus 30 as described above has the duct 31 forming the channel, the impeller 32 disposed in the duct 31, the bearing 33 of the impeller 32 provided in the duct 31, and the cap 34 closing the rear end of the bearing 33, and the stream straightening grooves 34a are formed in the external face of the cap 34, the rotation component of the water stream very close to the external face of the cap 34 can be reduced by the stream straightening grooves 34a.
Moreover, since it is sufficient to form the stream straightening grooves 34a, not a stream straightening plate (stationary vane) in the external face of the cap 34, a number of stream straightening grooves can be formed by, for example, cutting in the limited outer circumference length of the cap 34 whose diameter is relatively small. Thus, the rotation component of the water stream very close to the external face of the cap 34 can be JJ-11737/cs sufficiently reduced.
Further, since the stream straightening grooves, not a stream straightening plate, are formed in the external face of the cap 34, the size of the cap 34 can be reduced.
Further, since what is formed in the external face of the cap 34 is, not a stream straightening plate but, the stream straightening grooves 34a, it becomes unnecessary to position the cap 34 with the other stationary vanes 31b1 and 31c1.
Therefore, formation of the stream straightening grooves 34a in the external face of the cap 34 is particularly effective in the case where the stationary vane 31c1 is formed toward the portion facing the cap 34, in the internal face of the duct 31 as in the embodiment.
Since what is formed in the external face of the cap 34 are the stream straightening grooves 34a, not a stream straightening plate, n o interference occurs between the cap 34 and the bilge pipe 37.
Since the water jet propulsion apparatus of the present invention includes a duct forming a channel, an impeller disposed in the duct, a bearing of the impeller provided in the duct, and a cap closing the rear end of the bearing, and stream straightening grooves are formed in the external face of the cap. Consequently, a rotation component of a water stream very close to the external face of the cap can be reduced by the stream straightening grooves.
JJ-11737/cs _g_ Moreover, since it is sufficient to form the stream straightening grooves, not a stream straightening plate (stationary vane) in the external face of the cap, a number of stream straightening grooves can be formed in the limited outer circumference length of the cap whose diameter is relatively small. Thus, the rotation component of the water stream very close to the external face of the cap can be sufficiently reduced.
Further, since the stream straightening grooves, not a stream straightening plate, are formed in the external face of the cap, the size of the cap can be reduced.
Further, since what is formed in the external face of the cap is, not a stream straightening plate but, stream straightening grooves, it becomes unnecessary to position the cap with the other stationary vanes.
Therefore, formation of the stream straightening grooves in the external face of the cap is particularly effective in the case where a stationary vane is formed toward the portion facing the cap, in the internal face of the duct as an embodiment of the invention.
Although the embodiment of the invention has been described above, the invention is not limited to the foregoing embodiment but can be properly modified within the range of the gist of the invention.
JJ-11737/cs
Claims (2)
1. A water jet propulsion apparatus comprising a duct forming a channel, an impeller disposed in the duct, a bearing of the impeller provided in said duct, and a cap closing the rear end of the bearing, characterized in that stream straightening grooves are formed in the external face of the cap.
2. The water jet propulsion apparatus according to claim 1, characterized in that a stationary vane is formed toward said cap in a portion facing said cap, in the internal face of said duct.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001-270154 | 2001-09-06 | ||
| JP2001270154A JP3963680B2 (en) | 2001-09-06 | 2001-09-06 | Water jet propulsion machine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2395728A1 CA2395728A1 (en) | 2003-03-06 |
| CA2395728C true CA2395728C (en) | 2005-02-15 |
Family
ID=19095849
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002395728A Expired - Fee Related CA2395728C (en) | 2001-09-06 | 2002-07-26 | Water jet propulsion apparatus |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US6840826B2 (en) |
| JP (1) | JP3963680B2 (en) |
| CA (1) | CA2395728C (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111776184B (en) * | 2013-03-15 | 2022-11-04 | S·布洛诺斯基 | Marine duct propeller jet propulsion device |
| US10597129B1 (en) | 2013-03-15 | 2020-03-24 | Stefan Broinowski | Marine ducted propeller mass flux propulsion system |
| CN106741784A (en) * | 2017-01-19 | 2017-05-31 | 罗朝霞 | Electric environment protecting hydrojet propelled ship |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1824667A (en) * | 1926-07-20 | 1931-09-22 | Syndicat Vaproc | Rotary propeller |
| US3083529A (en) * | 1959-03-24 | 1963-04-02 | Charles W F Hemilton | Hydraulic jet propulsion apparatus for water-borne craft |
| GB1363637A (en) * | 1970-11-13 | 1974-08-14 | Ua Eng Ltd | Hydraulic jet propulsion means |
| JPS6030599B2 (en) * | 1980-12-18 | 1985-07-17 | 川崎重工業株式会社 | Mixed flow water injection propulsion device |
| US5123867A (en) * | 1990-05-10 | 1992-06-23 | Stefan Broinowski | Marine jet propulsion unit |
| JPH05105189A (en) | 1991-10-14 | 1993-04-27 | Sanshin Ind Co Ltd | Water jet propulsion machine |
| US5759074A (en) * | 1996-09-25 | 1998-06-02 | Brunswick Corporation | Impeller mounting system for a personal watercraft |
| JP2000161126A (en) * | 1998-11-30 | 2000-06-13 | Yamaha Motor Co Ltd | Engine structure for small-sized vessel |
| US6273768B1 (en) * | 2000-04-07 | 2001-08-14 | Bombardier Motor Corporation Of America | Water jet propulsion unit with counter-rotating impellers |
| US6273769B1 (en) * | 2000-05-02 | 2001-08-14 | Chris W. Bell | Transparent thrust cone for monitoring oil level and condition in watercraft jet propulsion system |
-
2001
- 2001-09-06 JP JP2001270154A patent/JP3963680B2/en not_active Expired - Fee Related
-
2002
- 2002-07-26 CA CA002395728A patent/CA2395728C/en not_active Expired - Fee Related
- 2002-08-30 US US10/231,315 patent/US6840826B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP3963680B2 (en) | 2007-08-22 |
| JP2003072686A (en) | 2003-03-12 |
| US6840826B2 (en) | 2005-01-11 |
| CA2395728A1 (en) | 2003-03-06 |
| US20030045183A1 (en) | 2003-03-06 |
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