JPS626892A - Water jet generating device - Google Patents

Abstract

PURPOSE:To eliminate the necessity of installation of a sealed structure type pipe, by constituting the rotor and stator of a three-phase induction motor with an impeller ring set around impeller blades and a water suction/discharge side section cooperating with the impeller ring, respectively. CONSTITUTION:An impeller ring 44 set around impeller blades 42 is disposed in an annular recess 44A formed in a water 56 of a three-phase induction motor are embedded in the outer peripheral surface of the impeller ring 44 over the entire periphery of the latter. Further, a stator 58 of the three-phase induction motor is laid in a part in the water suction/discharge duct 30, opposing the impeller ring 44, that is, recess 44A. Accordingly, when the stator 58 on the water suction/discharge duct 30 side is electrically energized, the rotor in the outer peripheral surface of the impeller ring 44 is moved relative to the stator, so that the impeller is rotated. With this arrangement it is possible to completely eliminate the problem of sealing around an impeller drive shaft 38.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a water jet generator, and more specifically, a non-driven water jet generator that can be effectively applied as a water jet propulsion device to a hydrofoil boat. This invention relates to a water jet generator that drives an impeller in a axial manner.

BACKGROUND OF THE INVENTION A water jet propulsion device used in a water jet boat such as a so-called hydrofoil boat is, for example, as shown in FIG. An extending propulsion water intake/discharge duct 14 is provided, and an intake port 14</b>A of the water intake/discharge duct 14 opens into the boat bottom 10 . Therefore, the water intake and discharge ducts are curved within the hull.

A rectifying cone 16 is disposed coaxially in a straight line portion of the water intake/discharging duct 14, and rotating impellers 1B and fixed blades 20 are alternately attached to the rectifying cone 16.

The fixed blade 20 has one end fixed to the rectifying cone 16 and the other end fixed to the inner wall of the water intake/discharge duct 14 so as to support the rectifying cone 16. On the other hand, the rotating impeller 18 is rotatably supported by the rectifying cone 16,
Further, it is rotationally driven by an impeller drive shaft 22 that penetrates the wall of the water suction and discharge duct 14 and extends coaxially with the water suction and discharge passage 14 .

Another water jet propulsion device as shown in Fig. 5 is
An inlet 14B of the water suction and discharge duct 14 extending from the bottom 10 to the stern end wall 12 hangs down from the bottom 10 and opens toward the front of the ship.

The rest of the structure is similar to that of the water jet propulsion device shown in FIG.

Although not shown in Figures 4 and 5, the conventional water jet propulsion system as described above uses a main engine (such as a diesel engine or an electric motor) installed inside the hull, specifically in the engine room. ) is coupled to an impeller drive shaft 22. The impeller drive shaft 22 is housed in a through pipe 24 that penetrates the wall of the water intake and discharge duct, and although not shown in detail in the attached drawings, a tube bearing is arranged in the through pipe to drive the impeller. The drive shaft 22 is rotatably supported.

Furthermore, water sealing portions are provided at both ends of the through tube 24, respectively. Further, the impeller drive shaft 22 is coupled to an intermediate shaft within the engine room, and the intermediate shaft is coupled to the output shaft of the main engine.

Thus, when the main engine is driven, the rotation of its output shaft is transmitted to the impeller drive shaft 22 via the intermediate shaft, the rotary impeller 18 is rotated, and the water suction and discharge duct 1 is rotated.
Water is sucked in through the intake port 4, and the water is discharged through the discharge port, and the reaction force propels the boat. Penetration pipe 24 at that time
Entry of water into the tank is prevented by water seals at both ends.

Problems to be Solved by the Invention However, the water jet propulsion device having the above structure has the following major problems.

The first problem is that the mechanically rotating impeller drive shaft must pass through a through tube provided in the wall of the water intake and discharge duct. Providing a pipe that connects the impeller in the water suction and discharge duct to the hull body requires a completely water-tight structure, which is very troublesome and requires a large amount of cost.

The second problem is that an intermediate shaft must be provided at the interface between the main engine and the impeller drive shaft. This intermediate shaft secures space for the impeller drive shaft, which needs to be pulled out into the hull during maintenance and inspection. Therefore, the engine room must be of sufficient size and a considerable amount of valuable interior space for ships must be allocated, which is a major problem for ships.

The third problem is that the impeller, impeller drive shaft, intermediate shaft, and main engine must be arranged on the same axis, and their axial length is long, which is a constraint on the arrangement of the engine room.

The above-mentioned problems occur to varying degrees not only when the water jet generator is used as a jet propulsion device in a watercraft, but also when it is used as an axial flow pump or the like.

Therefore, the first object of the present invention is to provide a water jet that eliminates the problem of water sealing from driving an impeller without requiring a pipe that penetrates the wall of a water intake and discharge duct and requires a water sealing structure like a penetrating pipe. The purpose is to provide a generator.

A second object of the present invention is to eliminate the need for mechanical power transmission means such as an intermediate shaft interposed between the drive source and the impeller, and to eliminate the need for arranging the impeller and the drive source in a straight line. The purpose of the present invention is to provide a water jet generator that does not require a water jet generator.

Means for solving the problem, namely, according to the invention, a water intake and discharge duct;
An impeller blade arranged in the water suction and discharge duct, an impeller ring provided around the impeller blade, a rotor of a three-phase induction motor provided in the impeller ring, and a rotor that cooperates with the rotor. Thus, there is provided a water jet generator characterized by comprising a stator of a three-phase induction motor provided on the side of the water suction and discharge duct.

In the water jet generator according to the present invention as described above, the impeller ring provided around the impeller blade and the water suction and discharge duct side portion that cooperates with the impeller ring are connected to the three-phase induction motor. Since the rotor and the stator each constitute the rotor, the rotor moves relative to the stator by electrically energizing the stator on the side of the water suction and discharge duct. That is, the impeller ring rotates, which causes the impeller blades to rotate and generate a water jet.

EXAMPLE Hereinafter, an example in which a water jet generator according to the present invention is implemented as a water jet propulsion device for a ship will be described with reference to the accompanying drawings.

FIG. 1 is a sectional view taken along the axis of rotation of an embodiment of the water jet propulsion device according to the present invention applied to a ship, and FIG. 2 is a sectional view taken along the line A-A of the water jet propulsion device in FIG. FIG. As shown in FIG. 1, the water jet propulsion device according to the present invention is equipped with a propulsion water suction and discharge duct 30, which is not shown in FIGS. 1 and 2. However, as in the conventional example shown in FIG. 4, the water jet propulsion device has a submerged structure, extending from the bottom of the ship to the end wall of the stern. The suction port of the water suction and discharge duct may hang down from the bottom of the ship and open toward the bow, as in the conventional example shown in FIG.

A rectifying cone 32 is disposed in a straight line portion of the water suction and discharge duct 30 in a coaxial relationship with the water suction and discharge duct, and the rectification cone 32 is supported by a fixed blade 34 . An impeller 36 is rotatably attached to the rectifying cone 32 between the adjacent fixed blades 34 . As shown in FIG.
The impeller blade 42 includes a plurality of (six in the illustrated example) impeller blades 42 arranged at approximately equal angles to the boss 40 of the impeller blade 40, and an impeller ring 44 provided around the impeller blades 42. The impeller ring 44 is accommodated in an annular recess 44A formed in the water suction and discharge duct 30, and the inner surface of the impeller ring 44 is substantially coplanar with the inner surface of the water suction and discharge duct 30.

As shown in FIG. 1, the rotating shaft 38 does not pass through the wall of the water intake and discharge duct 30, but is housed within the rectifying cone 32, and its rear part is connected to a rotating bearing 46 fixed to the rectifying cone.
Furthermore, an enlarged diameter portion 48 is provided at the front end of the rotating shaft 38, and a thrust/rotation bearing 50 and a thrust bearing 52 are provided so as to sandwich the enlarged diameter portion 48. The impeller is supported by bearings 46 and 50 for its rotation, and by bearings 52 and 52 for the thrust generated by its rotation.

On the other hand, a rotor conductor (secondary conductor) 54 and a rotor core (secondary core) 56 of a three-phase induction motor are embedded in the outer peripheral surface of the impeller ring 44 over its entire circumference. A stator 58 of the three-phase induction motor is installed in a portion of the water suction and discharge duct 30 that faces the impeller ring 44, that is, in the recess 44A described above. The stator 58 includes a stator core (-order core) 60 provided with a slot and a stator conductor (-order conductor) 6 housed in the slot.
2, and the sealing material lump 6 is inserted into the slot.
4 is filled to seal the stator conductor 62 with water. As shown in FIG. 2, the stator 58 extends in the circumferential direction of the impeller ring over a substantial length of the impeller ring, and the stator core and stator winding described above extend in the circumferential direction of the impeller ring. are arranged in

In addition, as shown in FIGS. 1 and 2, the magnetic pole surface of the stator 58 is located as close as possible to the outer circumferential surface of the impeller ring 44 to minimize magnetic resistance and direct lines of magnetic force to the impeller ring surface. It is made to occur almost perpendicularly to the surface.

Furthermore, a sealing portion 66 is provided at the opening edge of the recess 44A so as to seal the inside of the recess as much as possible and protect the rotor and stator 70 of the three-phase induction motor. The sealing portion is very close to the side edge of the impeller ring 44 so as not to contact the impeller ring and create a resistance to its rotation, and to produce as much of a water-sealing effect as possible;
For example, they can be made from a lubricating, water-repellent material such as Teflon.

However, materials such as grease may also be used.

Further, the water jet propulsion device described above is driven and controlled by a device as shown in FIG. In FIG. 3, reference number 68 is a prime mover such as a diesel engine,
A three-phase alternating current generator 70 is coupled to its output shaft. The output of the generator 70 is supplied to the general load inside the ship, and is also converted into direct current by a rectifier 72 and supplied to an inverter 74 . This inverter 74 is controlled by a speed setting signal from the bridge control device 76, and supplies three-phase power to the stator 58 at a frequency corresponding to the set speed.

Thus, the stator 58 generates a moving magnetic field on the magnetic pole surface facing the rotor on the outer peripheral surface of the impeller ring. The moving magnetic field passes through the secondary core 54 of the rotor of the impeller duct, resulting in eddy currents in the secondary conductor, and the interaction of the currents and the magnetic field generates a rotational force. Therefore, the impeller blades 42 rotate about their axis of rotation 38 to generate a thrust force by the water jet to propel the ship, for example. Then, the rotation speed is determined by the inverter 7
This can be easily controlled by controlling the frequency of the three-phase power that 4 supplies to the stator 58.

Thus, the water jet propulsion system does not require mechanical connection of the electric motor inside the hull to the impeller blades provided in the impeller ring or its rotating shaft, and also does not require any electrical connection to the impeller ring. The impeller can be rotated underwater without having to do so.

In addition, if the water jet propulsion device has a submerged structure,
The ship can also be moved backwards by driving the impeller in reverse.

Further, in the embodiment described above, a pair of rotating impellers are provided, and each rotating shaft is independent.

With this configuration, each impeller can be alternately rotated in opposite directions. Further, in the above embodiment, the rotary impeller has a dual-role configuration, but it may have a multi-stage configuration of three or more stages, or, conversely, a single-role configuration.

Although the embodiments of the water jet propulsion device of the present invention have been described above, the water jet propulsion device of the present invention is applicable not only to hydrofoil ships but also to ships that can use the water jet propulsion device. Applicable. In particular, since it is not necessary to seal the impeller shaft with water, the effect is extremely large when used in a deep submersible.

Further, although the shape of the water suction and discharge duct is arbitrary, by configuring the water jet generator in the same manner as the structure of the water jet propulsion device described above, the water jet generator can be
It can also be applied to general-purpose axial flow pumps, general-purpose axial flow fans, etc.

Effects of the Invention As is clear from the above description, the water jet generator according to the present invention has the following excellent effects that cannot be obtained with conventional water jet generators.

■ Since the impeller drive source is a three-phase induction motor consisting of an impeller ring and a stator of the water intake and discharge duct, no other mechanical drive source is required, and when used as a propulsion device for ships. There is no need to have an engine room nearby. Therefore, the impeller device can be installed at any location remote from the engine room, and conversely the engine room can be installed at any location remote from the impeller device.

■ Since there is no need to connect the impeller with the outside of the water suction and discharge duct, there is no need to provide a water-sealing structure pipe like the through pipe of the water suction and discharge duct, which completely eliminates the problem of water seal around the impeller drive shaft. will be opened to

■ Also, since no intermediate shaft is required, the drive system can be made smaller, and when used as a propulsion device for a ship, the space in the engine room can be reduced.

■ Furthermore, since there is no intermediate shaft and the impeller is directly configured as a three-phase induction motor and is electrically driven, there is no need for mechanical power transmission means, and the impeller, impeller shaft, intermediate shaft, and drive There is no problem with having to place the sources on the same axis. Therefore, when used as a propulsion device for a ship, various equipment can be freely arranged in the engine room, and a smaller space is required than in the past.

■ Since an impeller ring is provided around the impeller and the impeller ring is driven, the rigidity of the impeller is increased.

■ The impeller support shaft does not need to transmit torque.
Its diameter can be reduced.

(2) Furthermore, by controlling the frequency of the driving power of the three-phase induction motor, the number of revolutions of the impeller can be freely, ie, unlimitedly selected.

■ By supporting each impeller with an independent rotating shaft, the multi-stage impellers can be rotated alternately in opposite directions.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view along the rotation axis of a water jet propulsion device embodying the present invention, FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1, and FIG. Electrical system diagrams of drive control devices for water jet propulsion devices, FIGS. 4 and 5 are schematic views of conventional impeller devices. [Main reference numbers] 10. Bottom of ship 12. Stern end wall 14. Water intake and discharge duct 16. Rectification cone 18. Rotating impeller 20.
Fixed blade 22... Impeller drive shaft 24... Penetration pipe 30... Water intake and discharge duct 32... Rectifying cone 34... Fixed blade 36... Rotating impeller 38... Rotating shaft 42... Impeller blade 44... Impeller ring 44A...Recessed portion 54...Rotor core 56...Rotor conductor 58...Stator
60...Stator secondary core 62...Stator conductor 68...
Prime mover, 70... AC generator 72... Rectifier, 74
... Inverter 76 ... Bridge control device patent applicant
Sumitomo Heavy Industries, Ltd. Sub-Agent Patent Attorney Masahiko Arai Figure 4 Factor 5

Claims (1)

[Claims] (1) A water suction and discharge duct, an impeller blade arranged in the water suction and discharge duct, an impeller ring provided around the impeller blade, and a rotor of a three-phase induction motor provided in the impeller ring. and a stator of a three-phase induction motor provided on the water suction and discharge duct side so as to cooperate with the rotor.