JP2002068083A - Vertical water jet propeller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a swivel vertical water jet propeller of low energy loss, capable of converting the kinetic energy by an impeller into the pressure energy, and injecting the pressurized water from a discharge opening while keeping the pressure energy. SOLUTION: A spiral easing 17 is mounted on an outer peripheral part of a pump easing 4, the spiral easing 17 is gradually enlarged toward a discharging port 19, an area of the discharging port is reduced, the discharge opening 20a is bent and opened to a propulsion rear part of the ship's bottom 2, the swivel current produced by the impeller 11 is pressurized in the centrifugal direction and transferred to the discharge port 19, and the kinetic energy by the impeller 11 is converted into the pressure energy by the spiral casing 17, and injected from the discharge opening 20a while keeping the pressure energy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water jet propulsion device for a ship which enables sailing in shallow water, and more particularly to a vertical water jet propulsion device which can turn by changing the direction of the discharge port of the ship. Regarding improvement.

[0002]

2. Description of the Related Art Conventionally, a vertical water jet propulsion device for a ship traveling in a shallow water pressurizes water sucked from a central suction port with an impeller, and rectifies the pressurized swirling flow with a plurality of diffusers. An apparatus that fills the inside of a cylindrical pressure casing and injects a water stream from a discharge port at the bottom of the pressure casing to obtain a thrust of a ship is disclosed in, for example, Japanese Patent Application Laid-Open No.
Known as described in 86693.

[0003]

However, in the above-mentioned conventional apparatus, since pressurized water pressurized in the centrifugal direction is supplied to the casing, kinetic energy is not directly converted into pressure energy, so that the efficiency is low. The discharge port is also rapidly reduced, resulting in large contraction loss.When heavy objects are loaded, back pressure is applied to the discharge side, and the operating point is applied to the small flow rate side, which tends to cause cavitation. Was. SUMMARY OF THE INVENTION It is an object of the present invention to provide a vertical water jet propulsion device that converts kinetic energy generated by an impeller into pressure energy and injects it from a discharge port while maintaining the pressure energy.

[0004]

The gist of the present invention resides in that a pump casing is disposed at the center of a casing which is pivotally disposed on a horizontal plane, and water sucked from a suction port at the bottom of the ship is supplied to the pump casing. Pumping water with a hanging impeller,
In a vertical water jet propulsion device that obtains thrust of a ship by injecting the pumped water into the water from a discharge port on a bottom surface of a casing, a spiral casing surrounding a rear end of an impeller is disposed on an outer peripheral portion of the pump casing. The spiral casing is gradually expanded toward the discharge port, and the discharge port of the discharge pipe connected to the discharge port is opened to the rear of the ship's bottom for propulsion. Is converted to And
The discharge pipe forms a cut surface in an oval shape, reduces its oval area and hangs down to the bottom of the ship, opens its discharge port by bending behind the bottom of the ship, and accelerates pressurized water. The jet is injected into the water behind the propulsion of the ship. Also, the blade wound around the hub of the impeller consists of a plurality of spiral blades,
The outer peripheral edge of the spiral blade is made to approach the inner peripheral surface of the pump casing, the outer peripheral tip is protruded in the direction of the suction casing from the hub, and the suction portion inside the outer peripheral tip is greatly widened to extend the tip of the blade. The section guides the flow of water and improves the balance efficiency with a plurality of spiral blades. Then, the water flow that has flowed in the direction of the rotation axis increases the indentation pressure on the blade surface of the screw blade, the suction pressure is improved by the indentation pressure, cavitation is prevented, and the centrifugal force of the mixed flow blade and the blade surface are reduced. The pressure is gradually increased by the lift, and the pressure is further increased and the speed is increased by the centrifugal action of the centrifugal blade.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vertical water jet propulsion device for a watercraft according to the present invention is constructed as described above. When the impeller is rotated, water is sucked from a suction port of a suction casing to form a spiral. The kinetic energy is converted to pressure energy without energy loss due to turbulence, because the water flow pressurized by the wings is pressurized in the centrifugal direction and the swirling flow is transferred to the enlarged portion on the discharge side of the spiral casing. It is. And the pressurized water flows into the discharge pipe from the spiral casing,
The ship is propelled by injecting pressurized water from the discharge port that has been reduced in size while maintaining the pressure with the discharge pipe.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to an embodiment. First, in FIG. It is supported on a gantry 3 fixed to the ship bottom 2. The pump casing 4 of the vertical water jet propulsion device 1 is connected to the suspension stand 5. Stand 3
A gear case 6 is supported on the upper part of the frame. A horizontal input shaft 7 interlockingly connected to a driving device (not shown) is inserted through the gear case 6, and a bevel gear 8 is fitted to a tip of the input shaft 7. A drive shaft 9 hangs down from the gear case 6, and a bevel gear 10 fitted to the upper end of the drive shaft 9 meshes with the bevel gear 8 of the input shaft 7. An impeller 11 fixed to the lower end of the drive shaft 9 is provided in the pump casing 4 so that the impeller 11 is rotated by power transmitted from the input shaft 7.

As shown in FIG. 2, the pump casing 4 is expanded upward and divergent, and an impeller 11 disposed on the pump casing 4 is attached to a conical hub 12.
〜4 spiral wings 13 are wound around the spiral wings 1
The outer peripheral edge 13a of the helical blade 3 is brought closer to the inner peripheral surface of the pump casing 4 so that the axially symmetric spiral blades 13 can improve the balance efficiency. The outer peripheral tip 13b of the spiral blade 13 projects below the hub 12 to form a wide suction portion 4a inside the outer peripheral tip 13b of the spiral blade 13. The inflow of water is guided by the outer peripheral end portion 13b to cause an inducer action. The suction part 4 at the lower end of the pump casing 4
The suction casing 14 whose lower part is expanded is connected to a. The suction port 14a of the suction casing 14 is inclined to one side, so that the running water flow of the ship can easily flow in. A screen 16 for dust removal is provided at a suction port 14a of the suction casing 14, and the suction port 14 is inclined.
The water flowing from the suction port 14a is guided to the suction part 4a at the lower end of the pump casing 4 by inclining the lattice of the screen 16 in the same direction as that of the screen a.

A spiral casing 17 is formed on the outer periphery of the upper end of the pump casing 4, and as shown in FIG. 3, the volume of the spiral chamber 18 is gradually increased toward the discharge side. The pressurized water pressurized by the impeller 11 is configured to flow from the rear end of the spiral blade 13 into the swirl chamber 18 of the spiral casing 17 while turning, and converts kinetic energy generated by rotation of the impeller 11 into pressure energy. It is converted. An elliptical outlet 19 is provided on the bottom surface of the rear end of the spiral chamber 18, and a discharge pipe 20 for changing the flow of the spiral chamber 18 downward while gradually drawing a curve at the outlet 19 of the spiral casing 17. Are connected. Discharge pipe 2
Reference numeral 0 indicates that the cut surface is formed in an oval shape, the area of the oval shape is slightly reduced, and the oval is hung down to the bottom 2 of the ship. Open to the public. A drive 21 is supported on an upper side end of the gantry 3, and a worm 22 fitted on the drive 21 is engaged with a worm wheel 23 fitted on an upper end of the suspension base 5. The suspension table 5 is rotated to change the directions of the suction port 14a and the discharge port 20a of the vertical water jet propulsion device 1.

[0009]

The waterjet propulsion device for a watercraft according to the present invention is constructed as described above, and since the spiral casing and the discharge pipe are provided, energy loss due to turbulence and the like is eliminated. That is, in the conventional device,
Since the pressurized water pressurized in the centrifugal direction is supplied to the pressure casing and injected from the outlet of the casing that has been rapidly reduced, the kinetic energy is not directly converted to pressure energy, and the loss at the outlet is greatly reduced and efficiency is increased. However, according to the present invention, the spiral casing is disposed on the outer peripheral portion of the pump casing, so that the swirling flow generated by the rotation of the impeller is pressurized in the centrifugal direction, and the discharge side of the spiral casing is discharged. The kinetic energy of the impeller can be converted to pressure energy by the spiral casing. And since the discharge pipe connected to the discharge port of the spiral casing is opened behind the propulsion at the bottom of the ship, it is possible to spray from the discharge port while maintaining the pressure energy. Furthermore, the outer peripheral edge of the spiral blade wound around the hub of the impeller is made closer to the inner peripheral surface of the pump casing, and the outer peripheral tip is protruded more toward the suction port than the hub, so a wide suction part is formed. As a result, the diameter of the pump becomes larger, and the outer peripheral tip portion performs the function of a positive displacement pump. The propulsive force increases the suction amount of the fluid to increase the suction efficiency.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view of a vertical water jet propulsion device according to the present invention.

FIG. 2 is a vertical sectional side view of a main part of the water jet propulsion device.

FIG. 3 is a conceptual diagram in which a spiral casing is arranged on the outer periphery of a pump casing.

FIG. 4 is also a perspective view of a discharge pipe connected to a spiral casing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vertical water jet propulsion machine 2 Ship bottom 4 Pump casing 11 Impeller 12 Hub 13 Spiral blade 13a Outer edge 13b Outer edge tip 14 Suction casing 14a Suction port 17 Spiral casing 19 Discharge port 20 Discharge pipe 20a Discharge port

Claims (3)

[Claims] 1. A pump casing (4) is disposed at the center of a water jet propulsion device which is disposed so as to be capable of turning on a horizontal plane, and water sucked from a suction port (14a) of a ship bottom (2) is pump casing (4). ) Is pumped up by an impeller (11) hanging down, and the pumped water is discharged from a discharge port (20) of a ship bottom (2).
In a vertical water jet propulsion device (1) that obtains thrust of a ship by injecting it into water from (a), a spiral casing (17) surrounding the rear end of an impeller (11) around the pump casing (4) The spiral casing (17) is gradually expanded toward the discharge port (19), and the discharge port (20a) of the discharge pipe (20) connected to the discharge port (19) is connected to the ship bottom ( 2) A vertical water jet propulsion machine characterized by having an opening behind the propulsion. 2. The discharge pipe (20) has a cut surface formed in an elliptical shape, the elliptical area is reduced, and the discharge pipe (20) hangs down to the ship bottom (2). The vertical water jet propulsion device according to claim 1, wherein the water jet propulsion device is bent and opened behind the propulsion of (2). 3. A blade wound around a hub (12) of the impeller (11) comprises a plurality of spiral blades (13 ...),
The outer peripheral edge (13a) of the spiral blade (13) is made closer to the inner peripheral surface of the pump casing, and the outer peripheral tip (13b) is protruded from the hub (12) toward the suction casing (14). The vertical water jet propulsion device according to claim 1 or 2, wherein: