JPH01277697A - Pumping plant for water-jet pusher - Google Patents

Abstract

PURPOSE:To aim at the structural simplification of a thrust balance mechanism by utilizing a pressure differential between a high pressure part at the downstream side of an impeller in a pump passage and a low pressure part at the nozzle side. CONSTITUTION:Since the side of a water jetting nozzle is lower in pressure than the downstream side of an impeller 4, pressure to the hull rear side is added to a drive shaft via a disk 10, whereby a thrust balance action is secured. The disk 10 is attached to the rear end side of this disk 10, and a high pressure chamber 12 and a low pressure chamber 14 for adding pressure to the disk 10 come to be proximately set up each at the downstream side and the nozzle side of the impeller 4, so that pressure can be taken in by each of relatively short interconnecting holes 13, 15.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a pump device for a water jet propulsion machine installed in a high-speed propulsion boat, etc., and particularly relates to a water jet propulsion machine with an improved thrust balance mechanism. For use in pump equipment.

(Prior art) Water jet propulsion machines applied to high-speed propulsion boats generally suck water from the bottom of the boat using an axial pump device.
It is pressurized and sprays a water jet rearward from a nozzle at the stern.

In the pump device used in such a water jet propulsion machine, a pump equipped with an impeller is used as a reaction force of the water jet injected toward the rear of the ship. A thrust force is generated toward the front of the ship. For this reason, a thrust bearing is installed on the drive shaft, but in high-speed propulsion boats, especially waterjet propulsion boats with an inducer, two shaft thrusts are applied: the impeller and the inducer.
Problems have arisen, such as the bearing structure becoming larger and maintenance becoming more complicated.

Therefore, various thrust reduction means have been considered so far,
For example, a back pressure chamber is installed on the downstream side of the impeller to reduce the pressure and generate a force in the opposite direction to the axial thrust (Japanese Patent Publication No. 50-34242, Utility Model Publication No. 55-50390).
(Japanese Patent Application Laid-Open No. 49-67), or a pressure-receiving disk is provided in the middle of the drive shaft, and the low pressure on the suction side is applied to the rear side of the hull of the disk to reduce shaft thrust (Japanese Patent Laid-Open No. 49-67
201 Publication) etc. are known.

(Problems to be Solved by the Invention) However, with the above-mentioned conventional thrust reduction means, the structure is complicated due to piping etc. for guiding the low pressure on the suction side to the rear end side of the drive shaft, and the manufacturing time is increased accordingly. There is a problem.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a pump device for a water jet propulsion machine that can simplify the configuration of a thrust balance mechanism and reduce manufacturing labor.

[Structure of the invention]

(Means for Solving Problem 11) The present invention uses an impeller in an IN flow type pump device used in a water jet propulsion machine that sucks water from the bottom of a ship, pressurizes it, and injects a water jet rearward from a nozzle at the stern. A space is provided between the rear end side of the attached drive shaft and the flow path in which the impeller is disposed, and the space is divided in the axial direction by a disk integrally attached to the rear end of the drive shaft, The front side of the hull from the disc of the space part is a high pressure chamber that communicates with a high pressure part downstream of the impeller, while the part of the space part rearward of the hull from the disc is a low pressure chamber that communicates with a low pressure part on the nozzle side, The present invention is characterized in that this constitutes a thrust balance mechanism that applies pressure toward the rear of the hull to the drive shaft via the disk.

(Function) According to the configuration of the present invention described above, since the pressure on the water jet nozzle side is lower than that on the downstream side of the impeller, pressure is applied to the drive shaft toward the hull side through the disk, and the thrust balance is improved. 1 effect is given.

The disk is attached to the rear end of the drive shaft, and the high-pressure chamber and low-pressure chamber for applying pressure to the disk are located close to the impeller downstream side and the nozzle side, respectively. Pressure can be introduced through a relatively short communication hole. Therefore, the configuration is the comparative fishing part rg, the number of parts is small, and no manufacturing effort is required.

(Example) An embodiment of the present invention will be described below with reference to FIG.

The water jet propulsion type pump device of this embodiment is applied to a high-speed propulsion boat, and sucks water from the bottom of the boat, pressurizes it, and injects a water jet from the stern to the rear (to the left in the figure).

A drive shaft 2 is inserted into a casing 1 built into the rear part of the hull, and the curved end of this drive shaft is connected to a drive machine (not shown) on the hull 11a side (right side in the figure).

An impeller 4 is attached to the drive shaft 2 via a boss portion 3 so as to be integrally rotatable, and a differential user 5 attached to the casing 1 is disposed downstream of the impeller 4. A sealing ring 6 is arranged between the differential user 5 and the drive shaft 2.

The water flow path 7 serving as a water jet is constituted by the inner surface of the casing 1, the boss portion 3 of the impeller 4, the ring 6 of the differential user 5, and the nozzle cone 8 provided behind (to the left) thereof. The rear end of the drive shaft 2 is located inside the front end of the nozzle cone 8.

Then, a space 9 is provided between the rear end side of the drive shaft 2 and the flow path 7 using the nozzle cone 8 and the ring 6 as a partition wall, and the space 9 is integrated with the rear end of the drive shaft 2. It is divided into two in the axial direction by the attached disk 10. In addition,
Reference numeral 11 indicates a sealing portion between the disk 10 and the nozzle cone 8.

The front side (right side) of the hull of the space 9 divided into two by this disk 10 is defined as a high pressure chamber 12, and this high pressure chamber 12 is connected to the flow path 7.
The downstream side of the impeller, for example, the rear end portion of the differential user 5 is communicated with the rear end portion of the differential user 5 through a communication hole 13, so that high pressure water at the rear end portion of the differential user 5 is introduced into the high pressure chamber 12.

Further, the rear side (left side) of the hull 9 of the space 9 divided by the disk 10 is defined as a low pressure chamber 14, and this low pressure chamber 14 is connected to the nozzle side of the flow path 7, for example, to the rear end portion of the nozzle cone 8 through a communication hole 15. The low-pressure water at the rear end of the nozzle cone 8 is introduced into the low-pressure chamber 14.

According to such a configuration, the disk 10 at the rear end of the drive@2
On the other hand, the high pressure at the outlet of the diff user 5 acts on the front (right side) surface of the hull, and the low pressure on the inner peripheral side of the outlet of the nozzle cone 8 acts on the rear (left) surface of the hull. Therefore, a thrust force is generated in the drive shaft 2 via the disk 10 toward the rear (to the left) of the hull, and a thrust balance mechanism is configured that reduces the thrust force generated by the impeller 4 toward the front (to the right) of the hull. . The configuration is such that a disk 10 is attached to the rear end side of the drive shaft 2, and a high pressure chamber 12 and a low pressure chamber 14 for applying pressure to the disk 10 are located near both sides of the disk 10 in the flow path 7. Since pressure is introduced, the communication hole 13 is relatively short.
．． It has a simple configuration based on 15.

Therefore, the configuration of the thrust balance mechanism can be simplified and the manufacturing effort can be effectively reduced.

In the above embodiment, the outlet portion of the differential user 5 of the flow path 7 is communicated with the high pressure chamber 12, but the outlet portion of the impeller 4 may be communicated with the high pressure chamber 12, as shown in FIG. In this case, the communication hole 13 is connected to the differential user 5.
It is also formed on the 6th part of the ring.

With such a configuration as well, the same effects as those of the above-mentioned embodiments can be obtained, of course, and even more pressure can be applied to the thrust balance disk 10 from the front side of the hull.

〔Effect of the invention〕

As described above, according to the present invention, the thrust balance mechanism can be realized with a simple configuration by utilizing the pressure difference between the high pressure part on the downstream side of the impeller and the low pressure part on the nozzle side of the pump flow path. , the manufacturing effort can be reduced, and other effects can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a partial sectional view showing an embodiment of the present invention, and FIG. 2 is a partial sectional view showing an embodiment of the bond of the present invention. 2... Drive shaft, 4... Impeller, 7... Channel, 8
... Nozzle cone, 9 ... Space, 10 ... Disk, 12 ... High pressure chamber, 13.15 ... Communication hole, 1
4...Low pressure chamber. Applicant's agent Hisashi Hatano 11th Ward

Claims (1)

[Claims] In an axial flow type pump device used in a water jet propulsion machine that sucks in water from the bottom of a ship, pressurizes it, and injects a water jet rearward from a nozzle at the stern, the impeller is located on the rear end side of the drive shaft with an impeller attached. A space is provided between the flow path and the flow path, and the space is divided in the axial direction by a disk integrally attached to the rear end of the drive shaft, and the front side of the hull from the disk of the space is connected to the impeller. While the high pressure chamber communicates with the high pressure section on the downstream side,
The rear side of the hull relative to the disc in the space is a low pressure chamber that communicates with a low pressure part on the nozzle side, thereby configuring a thrust balance mechanism that applies pressure to the rear of the hull to the drive shaft via the disc. A pump device for a water jet propulsion machine characterized by: