JP6025623B2 - Water jet propulsion machine - Google Patents

Description

  The present invention relates to a water jet propulsion device propelled by a water jet.

  Ships are suitable for mass transportation, have low transportation costs, and have a low environmental impact, so their value as a means of transportation is very high. In recent years, with increasing time value, further speeding up of ships is desired.

  Here, conventionally, a water jet propulsion machine is known as one of ships. This water jet propulsion machine can obtain a large propulsive force compared to the screw by jetting water sucked from the bottom of the ship from the rear of the ship, so it can be navigated at high speed, and it can also be navigated in shallow water. Is also possible.

  By the way, in the conventional water jet propulsion apparatus, since it is necessary to take in water from the water intake on the bottom of the ship and introduce it into the pump, it is inevitable that the suction pipe becomes a curved pipe. And, as the distance between the water intake and the pump inlet becomes shorter, the angle of the curved pipe line becomes steeper, and the drift component of the water flow when flowing into the pump becomes larger, leading to a decrease in pump performance.

  Here, Patent Document 1 discloses a water jet propulsion device that is provided with a guide member so as to cover an impeller shaft inside a suction pipe (suction duct), and smoothes the water flow and suppresses the generation of vortex flow. ing.

Japanese Utility Model Publication No. 5-58391

  However, a gap is formed between the guide member disclosed in Patent Document 1 and the inner peripheral surface of the suction pipe, and vortex flows are generated by joining water flowing along the surface of the guide member at this position. May occur.

  The present invention has been made in consideration of such circumstances, and an object of the present invention is to provide a water jet propulsion device capable of preventing the generation of vortex around the impeller rotation shaft and improving the operation performance.

In order to solve the above problems, the present invention employs the following means.
That is, the water jet propulsion device according to the present invention includes a rotation shaft, a shaft cover that covers the rotation shaft, an impeller that rotates around the rotation shaft, and extends upstream along the rotation shaft. A jet passage provided with the impeller, and a curved passage connected to the upstream side of the jet passage and inclined to the rotation axis and extending to the upstream side; A suction flow path to be introduced into the passage, and the upstream side where the curved flow path in the suction flow path extends, on the opposite side across the rotation shaft, from the inner peripheral surface of the suction flow path to the rotation shaft A rectifying plate extending toward the surface, wherein the rectifying plate has a guide surface located on a virtual surface continuous with the surface of the shaft cover so as to guide the water flowing along the surface of the shaft cover. Yes, and said of the rectifier plate The inner surface is provided in a state where there is no gap between the pair of guide surfaces in the width direction perpendicular to the axis of the rotation shaft, and the distance in the width direction between the pair of guide surfaces is from the shaft cover. It is characterized by being formed in the same dimension as the width of the shaft cover over the inner peripheral surface of the suction flow path .

According to such a water jet propulsion device, the water flowing through the suction channel collides with the rotating shaft on the upstream side of the rotating shaft (or cover) and flows along the surface of the rotating shaft. And since the guide surface of a baffle plate is formed so that it may follow the surface of a rotating shaft, the water which distribute | circulates along the surface of a rotating shaft is guided, peeling is suppressed. Further, since the rectifying plate extends from the inner peripheral surface of the suction flow path toward the rotation shaft, the water guided and circulated by the guide surface is located downstream of the rotation shaft, that is, the rotation shaft and the suction shaft. The flow does not collide with the inner peripheral surface of the flow path and collide with the flow. Therefore, the generation of vortices around the rotation axis can be prevented.
In addition, since the current plate is formed in this way, the water flow around the rotating shaft (or cover) can be reliably prevented, and the state of the water flow field determined by the ship speed and the water suction speed Regardless of this, water can be guided while suppressing separation by the guide surface, and the generation of vortices around the rotation axis can be prevented.

  Furthermore, a pair of the guide surfaces of the rectifying plate is provided in the width direction perpendicular to the axis of the rotating shaft, and the pair of guide surfaces are connected to the suction channel and are connected to the inside of the suction channel. It may be smoothly continuous with the peripheral surface.

  By forming the current plate in this way, it is possible to suppress the water guided by the guide surface from stagnation at the connection portion with the inner peripheral surface of the suction flow path, and further uniform flow is possible. is there.

  Further, the guide surface of the rectifying plate may be formed to extend in the direction of the axis of the rotating shaft up to a connection portion between the bent flow path and the jet flow path.

  As described above, since the rectifying plate can be disposed up to the connection portion with the jet flow path that is the end of the curved flow path, it is possible to introduce water into the jet flow path in a state in which the generation of vortices is reliably suppressed. Therefore, further uniform flow is possible.

  Furthermore, the water jet propulsion device of the present invention further includes a rectifying plate trailing edge portion having a trailing edge guide surface that extends into the jet flow path along the rotation axis and is continuous with the guide surface of the rectifying plate. It may be.

  With such a trailing edge guide surface of the rectifying plate trailing edge, water can be guided even in the jet flow path, and a more uniform flow can be guided to the impeller, so that the operation performance can be improved.

  Further, a pair of the trailing edge guide surfaces of the rectifying plate trailing edge is provided in the width direction orthogonal to the axis of the rotation shaft, and the distance in the width direction between the pair of trailing edge guide surfaces is the rotation distance. You may become small as it goes to the downstream of the direction of the axis of an axis.

  Since the trailing edge is formed in this way, the flow of water guided by the trailing edge guide surface smoothly joins at the downstream end of the rectifying plate trailing edge, and the vortex is generated at this position. Can be prevented, and further uniform flow can be achieved.

  According to the water jet propulsion device of the present invention, it is possible to prevent the generation of vortex around the impeller rotating shaft by the guide surface of the rectifying plate, and to improve the operation performance.

1 is a schematic cross-sectional view of a water jet propulsion device according to a first embodiment of the present invention. 1 is a schematic cross-sectional view around a propulsion system in a water jet propulsion device according to a first embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing which shows the principal part of a propulsion system regarding the water jet propulsion machine which concerns on 1st embodiment of this invention, (a) is a side view, (b) is a top view, (c) is a rotating shaft. It is sectional drawing of the cross section orthogonal to an axis, and is AA sectional drawing of (a). It is a schematic sectional drawing which shows the principal part of the propulsion system in the water jet propulsion machine which concerns on the modification of 1st embodiment of this invention, Comprising: The same cross section as the AA cross section of FIG. 3 is shown. It is a schematic sectional drawing which shows the principal part of the propulsion system in the water jet propulsion machine which concerns on 2nd embodiment of this invention, Comprising: The same cross section as the AA cross section of FIG. 3 is shown. It is a schematic sectional drawing which shows the principal part of the propulsion system in the water jet propulsion machine which concerns on 3rd embodiment of this invention. It is a schematic sectional drawing which shows the principal part of the propulsion system in the water jet propulsion machine which concerns on the modification of 3rd embodiment of this invention. It is a schematic sectional drawing which shows the principal part of the propulsion system | strain in the water jet propulsion apparatus which concerns on 4th embodiment of this invention, (a) is a side view, (b) is a top view.

[First embodiment]
Hereinafter, a water jet propulsion device 1 according to an embodiment of the present invention will be described.
The water jet propulsion apparatus 1 is a ship that navigates with a propulsive force by sucking water W into the hull 2 and discharging it from the rear of the hull 2.

  As shown in FIGS. 1 and 2, the water jet propulsion device 1 includes the hull 2, a suction channel 10 that is provided in the hull 2 and sucks water W, a jet channel 11 that discharges, and a hull 2. A rotation drive unit 3 provided inside, a rotation shaft 4 that is driven to rotate by the rotation drive unit 3, and an impeller 5 that rotates together with the rotation shaft 4 inside the jet flow path 11 are provided. Further, the water jet propulsion device 1 includes a rectifying plate 13 provided on the inner peripheral surface of the suction flow path 10 on the upstream side of the impeller 5.

  The suction channel 10 is provided at a position near the stern portion 2b of the hull 2, and opens in the bottom 2c with respect to the traveling direction D, and is inclined upward from below toward the stern portion 2b from the bow portion 2a side. And a straight flow path 10a that extends and a curved flow path 10b that is continuous with the straight flow path 10a and is curved so as to be parallel to the ship bottom 2c.

  The jet channel 11 is connected to and communicates with the curved channel 10b of the suction channel 10, and water W is introduced from the suction channel 10 and extends along the traveling direction D toward the stern part 2b. It is formed in a nozzle shape so as to protrude from 2b and is open.

  The rotational drive unit 3 is a power source capable of generating rotational power, and is disposed on the bow portion 2 a side with respect to the suction flow path 10 inside the hull 2.

  The rotating shaft 4 is formed around an axis P that is attached to the rotation drive unit 3 and extends along the traveling direction D, and enters the suction flow channel 10 from the upstream side, and extends into the jet flow channel 11. The rotation drive unit 3 rotates about the axis P. Further, the rotary shaft 4 is provided with a shaft cover 4 b that covers the rotary shaft 4 itself from the outer peripheral side inside the suction flow path 10.

  The impeller 5 is disposed inside the jet flow path 11, is fixed to the rotation shaft 4, and rotates with the rotation shaft 4 about the axis P. Then, the pressure of the water W introduced into the jet flow path 11 from the suction flow path 10 is increased, and the water W is circulated toward the stern part 2b in the jet flow path 11 so that it can be discharged to the outside. The shaft cover 4 b extends in the direction of the axis P to a position where it does not interfere with the impeller 5.

Next, the current plate 13 will be described.
As shown in FIGS. 2 and 3, the rectifying plate 13 is on the opposite side of the axis P of the rotary shaft 4 with respect to the upstream side (the ship bottom 2c side) where the curved flow path 10b extends, that is, with the axis P interposed therebetween. At the position on the upper side, the suction channel 10 extends from the inner peripheral surface toward the rotation shaft 4.

  Moreover, in this embodiment, this baffle plate 13 is completely fixed to the shaft cover 4b, and there is no gap between the suction flow path 10 and the shaft cover 4b.

Further, the current plate 13 has a pair of guide surfaces 14 which are surfaces facing the width direction orthogonal to the axis P.
As shown in FIGS. 3B and 3C, the pair of guide surfaces 14 are formed such that the distance in the width direction is the same as the width (diameter) of the shaft cover 4b. The dimension in the width direction of the plate 13 is the same as the width of the shaft cover 4b over the entire area in the direction of the axis P and the radial direction of the axis P. Therefore, the guide surface 14 is formed so as to be continuous with the surface of the shaft cover 4b. Here, strictly speaking, the “continuation” indicates mathematical continuity. That is, when the radially extending curve on the surface of the shaft cover 4b and on the guide surface 14 is regarded as a function, the right limit and the left limit at an arbitrary point on this function indicate the same value. ing. However, it is not limited to this, and it is included that it is connected smoothly so that vortices due to separation do not substantially occur.
In this way, the guide surface 14 guides the water W flowing along the surface of the shaft cover 4b of the rotating shaft 4.

  Further, in the present embodiment, the guide surface 14 is formed to extend in the direction of the axis P to the connecting portion 12 between the curved flow path 10b and the jet flow path 11.

  According to such a water jet propulsion device 1, as shown in FIG. 3A, the water W flowing through the suction passage 10 collides with the shaft cover 4b on the upstream side of the rotating shaft 4, and the surface of the shaft cover 4b. Circulate along.

  Here, by providing the rectifying plate 13 formed so that the guide surface 14 is continuous with the surface of the shaft cover 4b, the water W while suppressing the separation of the water W flowing along the surface of the shaft cover 4b. To guide you. Furthermore, since the rectifying plate 13 extends from the inner peripheral surface of the suction flow path 10 toward the rotary shaft 4 (shaft cover 4b), it is guided and guided by the guide surface 14 as shown in FIG. The flowing water W does not wrap around between the shaft cover 4b and the inner peripheral surface of the suction flow path 10, that is, the downstream side of the rotary shaft 4, and the flow does not collide. Therefore, the generation of vortices around the rotating shaft 4 can be prevented.

  Furthermore, since the width-direction dimension of the rectifying plate 13 is the same as the width of the shaft cover 4b over the entire area, the entrainment of the flow of water W around the rotating shaft 4 can be reliably prevented, and the ship speed and water W Regardless of the state of the flow field determined by the suction speed, water W can be guided while reliably suppressing the separation by the guide surface 14, and the generation of vortices around the rotating shaft 4 can be prevented.

  According to the water jet propulsion device 1 of the present embodiment, by providing the guide surface 14 of the rectifying plate 13 so as to be continuous with the shaft cover 4b, the flow of water W inside the suction flow path 10 can be made uniform. Thus, the uniform flow can be introduced into the jet flow path 11. Therefore, the suction performance of the water W in the propulsion system such as the suction flow path 10 and the jet flow path 11 can be improved, and the occurrence of vibration due to the non-uniform flow can be suppressed and the operation performance can be improved.

  Here, as shown in FIG. 4, the shaft cover 4 b may not be provided on the rotating shaft 4. In this case, the rectifying plate 15 is provided extending from the inner peripheral surface of the suction flow path 10 toward the rotary shaft 4 with a gap from the rotary shaft 4. And the dimension of the width direction of the baffle plate 15 is made into the width dimension of the rotating shaft 4 so that the guide surface 16 may be located on the virtual surface which continues to the surface of the rotating shaft 4 (the definition of "continuous" is as above-mentioned). By making it the same, the water W can be guided while reliably suppressing the peeling by the guide surface 16, and the generation of vortices around the rotating shaft 4 can be prevented. The rectifying plate 15 may not be provided in a state of being spaced from the rotating shaft 4, and may be in a state of sliding in contact with the surface of the rotating shaft 4.

  In the present embodiment, the distance in the width direction between the pair of guide surfaces 14 (16) is the same as the width of the rotating shaft 4 or the width of the shaft cover 4b over the entire region of the rectifying plate 13 (15). It has become. However, the present invention is not limited to this, and at least the guide surface 14 is positioned on a virtual surface that is continuous with the surface of the rotary shaft 4 or the shaft cover 4b. Can be obtained.

  Further, the length dimension of the rectifying plate 13 (15) in the direction of the axis P may not be formed to extend to the connecting portion 12 between the curved flow path 10b and the jet flow path 11, and the shape and flow of the suction flow path 10 What is necessary is just to select an optimal dimension suitably according to the state of a field. However, in order to make it possible to introduce the water W into the jet channel 11 in a state in which the generation of vortices is more reliably suppressed, the guide surface 14 (16) reaches the connection portion 12 between the curved channel 10b and the jet channel 11. More preferably).

[Second Embodiment]
Next, a water jet propulsion device 1A according to a second embodiment of the present invention will be described.
In addition, the same code | symbol is attached | subjected to the same component as 1st embodiment, and detailed description is abbreviate | omitted.
In this embodiment, the shape of the rectifying plate 13A is different from that of the first embodiment with the first embodiment as a basic configuration.

  As shown in FIG. 5, the rectifying plate 13 </ b> A is formed so that the distance between the pair of guide surfaces 14 </ b> A in the width direction decreases from the rotating shaft 4 toward the inner peripheral surface of the suction flow path 10 and then increases. ing. Specifically, the guide surface 14A is a concave surface that is recessed inward in the width direction of the rectifying plate 13A, and the width direction dimension of the rectifying plate 13A is between the shaft cover 4b and the inner peripheral surface of the suction flow path 10. Smallest in midway position.

  Further, the rectifying plate 13A is a connecting portion 15A with the suction flow path 10 and the pair of guide surfaces 14A are directed outward in the width direction so that the guide surface 14A smoothly continues to the inner peripheral surface of the suction flow path 10. So as to be separated from each other.

  According to the water jet propulsion device 1 </ b> A of the present embodiment, the guide surface 14 </ b> A of the rectifying plate 13 </ b> A is a concave surface, so that the occupation range in the width direction of the rectifying plate 13 is reduced between the suction flow path 10 and the rotating shaft 4. Can be small. That is, since the flow area of the water W inside the suction flow path 10 can be secured, the suction flow rate of the water W can be secured, leading to improvement of the suction performance.

  Furthermore, since the guide surface 14A and the inner peripheral surface of the suction flow path 10 are smoothly connected by the connection portion 15A, the water W guided by the guide surface 14A is in contact with the inner peripheral surface of the suction flow path 10. Since it is possible to suppress stagnation at the connecting portion 15A, it is possible to suppress the generation of a vortex flow and the like to further uniform the flow.

  Note that the rectifying plate 13A of the present embodiment can also be applied to the rotating shaft 4 that is not provided with the shaft cover 4b as shown in FIG.

  Further, like the rectifying plate 13 </ b> A of the present embodiment, the guide surface 14 may be smoothly and continuously connected to the inner peripheral surface of the suction flow path 10 in the rectifying plate 13 of the first embodiment.

  Further, the rectifying plate 13A may be configured such that at least the guide surface 14A is positioned on a virtual plane continuous with the surface of the rotating shaft 4 (or the shaft cover 4b). It is good also as a three-dimensional shape that the distance between a pair of guide surfaces 14 changes also in a direction.

[Third embodiment]
Next, a water jet propulsion device 1B according to a third embodiment of the present invention will be described.
In addition, the same code | symbol is attached | subjected to the same component as 1st embodiment and 2nd embodiment, and detailed description is abbreviate | omitted.
In the present embodiment, the water jet propulsion device 1B is further provided with a rectifying plate trailing edge portion 21 connected to the rectifying plate 13 with the first embodiment as a basic configuration.

  As shown in FIG. 6, the rectifying plate trailing edge portion 21 is continuous with each of the pair of guide surfaces 14 and extends along the axis P into the jet flow path 11 toward the impeller 5. 22.

  Like the guide surface 14, the trailing edge guide surface 22 is formed so that the distance in the width direction is the same as the width of the shaft cover 4b so as to guide the water W flowing along the surface of the shaft cover 4b. Yes. That is, the widthwise dimension of the rectifying plate trailing edge 21 is the same as the width of the shaft cover 4b over the entire area in the direction of the axis P and in the radial direction of the axis P.

  Further, the rear edge guide surface 22 is viewed from the width direction so as to be inclined from the shaft cover 4b side toward the inner peripheral surface side of the suction flow path 10 as being separated from the guide surface 14 in the direction of the axis P. It is formed in a triangular shape. That is, the rear edge guide surface 22 is formed to extend obliquely toward the downstream side from the connecting portion between the shaft cover 4 b and the guide surface 14 so as to follow the flow of the water W.

  According to the water jet propulsion device 1B of the present embodiment, the rear edge guide surface 22 of the rectifying plate rear edge portion 21 can guide the water W while suppressing separation even inside the jet flow path 11, and a more uniform flow. It can be guided to the impeller 5.

  Furthermore, since the trailing edge guide surface 22 having a triangular shape when viewed from the width direction can be positioned just downstream of the flow of the water W, the rectifying plate trailing edge 21 can be minimized. Can be sized. Therefore, it is possible to efficiently guide the water W while ensuring the flow path area, to prevent the generation of vortices around the rotating shaft 4 and to improve the operation performance.

  Here, as shown in FIG. 7, as the rectifying plate trailing edge 31 is separated from the guide surface 14 in the direction of the axis P, the pair of trailing edge guide surfaces 32 are pivoted from the inner peripheral surface side of the suction flow path 10. You may form in triangle shape seeing from the width direction so that it may incline toward the cover 4b side. That is, the rear edge guide surface 22 of the current plate rear edge portion 21 in FIG. 6 is formed such that the rear edge guide surface 32 is inclined in the opposite direction.

  Further, although not shown, the trailing edge guide surface does not have to be formed in a triangular shape when viewed from the width direction. That is, the guide surface 14 is extended in the direction of the axis P as it is inside the jet flow path 11. A trailing edge guide surface may be formed as described above.

Further, as shown in FIG. 8, the rectifying plate trailing edge 41 is formed in a blade shape such that the distance in the width direction between the pair of trailing edge guide surfaces 42 decreases toward the impeller 5 on the downstream side. May be. The flow of the water W guided by such a trailing edge guide surface 42 smoothly joins at the downstream end of the rectifying plate trailing edge 41, and vortex generation can be prevented at this position. Therefore, the flow can be further uniformized, leading to improved driving performance.
The trailing edge guide surface 42 has a three-dimensional shape such that, for example, the distance in the width direction between the pair of trailing edge guide surfaces 42 also changes in the radial direction of the axis P according to the state of the flow field. It may be.

  Note that the current plate trailing edge 21 (31, 41) of this embodiment may be applied to the current plate 13A of the second embodiment.

Although the embodiment of the present invention has been described in detail above, some design changes can be made without departing from the technical idea of the present invention.
In the above-described embodiment, the rectifying plates 13, 13A, 15 are provided on the opposite side across the axis P of the rotating shaft 4 with respect to the upstream side where the curved flow path 10b extends. It does not indicate only the position completely opposite the upstream side. That is, even if the rectifying plates 13, 13 </ b> A, and 15 are provided at positions on the opposite side of the axis P with respect to the side where the water W collides with the rotating shaft 4, and slightly shifted in the circumferential direction of the axis P Good.

DESCRIPTION OF SYMBOLS 1 ... Water jet propulsion machine 2 ... Hull 2a ... Bow part 2b ... Stern part 2c ... Ship bottom 3 ... Rotation drive part 4 ... Rotating shaft 4b ... Shaft cover 5 ... Impeller 10 ... Suction flow path 10a ... Linear flow path 10b ... Curved flow Path 11 ... Jet flow path 12 ... Connection portion 13 ... Rectifying plate 14 ... Guiding surface 15 ... Rectifying plate 16 ... Guiding surface D ... Advancing direction P ... Axis W ... Water 1A ... Water jet propulsion machine 13A ... Rectifying plate 14A ... Guide surface DESCRIPTION OF SYMBOLS 15A ... Connection part 1B ... Water jet propulsion machine 21 ... Rectification plate trailing edge 22 ... Trailing edge guide surface 31 ... Rectification plate trailing edge 32 ... Trailing edge guide surface 41 ... Rectification plate trailing edge 42 ... Trailing edge guide surface

Claims (5)

A rotation axis;
A shaft cover covering the rotating shaft;
An impeller that rotates around the rotation axis,
A jet flow path extending upstream along the rotation axis and having the impeller disposed therein, and connected to the upstream side of the jet flow path and inclined with respect to the rotation axis toward the upstream side A suction passage that has a curved passage that extends and introduces water into the jet passage from outside the hull; and
A rectifying plate extending from the inner peripheral surface of the suction flow channel toward the rotation shaft on the opposite side of the rotation shaft with respect to the upstream side in which the bent flow channel extends in the suction flow channel,
With
The rectifying plate, so as to guide the water flowing along the surface of the shaft cover, have a guide surface positioned on a virtual plane contiguous to the surface of the shaft cover,
The guide surface of the current plate is provided with a pair in the width direction orthogonal to the axis of the rotating shaft, with no gap between the shaft cover,
The distance between the pair of guide surfaces in the width direction is formed to have the same dimension as the width of the shaft cover from the shaft cover to the inner peripheral surface of the suction flow path . The guide surface of the rectifying plate is provided with a pair in the width direction orthogonal to the axis of the rotating shaft,
2. The water jet propulsion device according to claim 1 , wherein the pair of guide surfaces are smoothly continuous with an inner peripheral surface of the suction flow path at a connection portion with the suction flow path. Said guide surface of said rectifying plate according to claim 1 or 2, characterized in that it is formed to extend in the direction of the axis of the rotary shaft to the connection portion between the jet flow path and the bent flow path Water jet propulsion machine. Continuously to the guide surface of the rectifying plate, along the rotation axis of claim 3, further comprising a rectifying plate trailing edge portion having an edge guide surface after extending to the jet flow path Water jet propulsion machine. The trailing edge guide surface of the rectifying plate trailing edge is provided with a pair in the width direction perpendicular to the axis of the rotating shaft,
5. The water jet propulsion device according to claim 4 , wherein a distance in the width direction between the pair of trailing edge guide surfaces decreases as it goes downstream in the direction of the axis of the rotation shaft.

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