JPH0775999B2 - Water jet propulsion machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial field of application) The present invention relates to a water jet propulsion machine used for a propulsion machine of a high-speed watercraft.

(Prior Art) Generally, a water jet propulsion machine is used for a propulsion machine of a high-speed boat, and as shown in FIG.
The water sucked from is pressurized by the pump blade 10 attached to the drive shaft 115 driven by the engine 116 such as an engine, rectified by the blade of the diffuser 117, and then the nozzle 1
From 18, the thrust is obtained by jetting from the stern rearward as a high-speed jet stream.

By the way, the gap formed between the inner surface of the pump casing 103 and the outer peripheral surface of the pump vane 101 in the above water jet propulsion machine was adjusted during the assembly of the water jet propulsion machine, but did not disassemble after assembly due to its structure. That was impossible to adjust.

(Problems to be solved by the invention) However, in the above-mentioned conventional water jet propulsion machine, the gap formed between the inner surface of the pump casing 103 and the outer peripheral surface of the pump blade 101 is adjusted only at the time of assembly,
When the water jet propulsion machine is used for a long period of time, the inner surface of the pump casing 103 and the flowing water surface such as the pump blades 101 may be worn away, or the above gap may become larger than the designed value due to erosion and corrosion. become. As a result, there is a problem in that the leak flow rate from the pressure surface of the pump blade 101 to the suction surface increases, and the pump performance significantly deteriorates.

In addition, the gap formed between the inner surface of the pump casing and the outer peripheral surface of the blade cannot be adjusted without disassembling the water jet propulsion machine body, and therefore a large amount of cost is required to restore the pump performance. It takes time and labor. As a result, the cycle of readjustment of the gap becomes long, and there is a problem in that the pump must be used with the pump performance deteriorated.

The present invention has been made in consideration of the above circumstances, and makes it possible to easily readjust the gap formed between the inner surface of the pump casing and the outer peripheral surface of the pump blade without disassembling the main body of the water jet propulsion device to constantly improve the pump performance. It is an object of the present invention to provide a water jet propulsion machine that maintains the best condition.

[Structure of Invention]

(Means for Solving the Problems) The present invention is configured as follows to solve the above problems.

That is, the present invention is a water jet propulsion machine in which water sucked from the bottom of a ship is pressurized by a pump and jetted from a nozzle in the stern to obtain thrust, and a gap formed by the inner surface of the tapered portion of the pump casing and the outer peripheral surface of the pump blade Is provided with a seal liner which is movable in the axial direction of the pump casing, and the seal liner is moved in the axial direction of the pump casing to adjust the seal gap between the inner surface of the seal liner and the outer peripheral surface of the pump blade. The adjusting mechanism is installed outside the pump casing.

(Operation) Since the present invention is configured as described above, when the seal gap formed by the outer peripheral surface of the pump blade and the inner surface of the seal liner expands due to wear or the like, and the pump performance deteriorates, the adjusting mechanism of the adjusting mechanism operates. By moving the seal liner in the axial direction of the pump casing by the adjusting operation, the seal gap can be returned to the design value and the pump performance can be restored to the optimum state. Further, since such a seal gap adjustment can be realized by an adjusting operation of an adjusting mechanism installed outside the pump casing, it can be easily and quickly performed without disassembling the main body of the water jet propulsion machine such as the pump casing. it can. For this,
It is possible to reduce a great amount of labor, time, and cost involved in disassembling and restoring the water jet propulsion device main body.

(Example) Hereinafter, a detailed description will be given based on an illustrated example of the present invention.

1 and 2 show a water jet propulsion machine according to an embodiment of the present invention. This water jet propulsion machine pressurizes the water sucked from the intake 14 at the bottom of the ship by rotating a pump blade 1 attached to a drive shaft 15 which is rotationally driven by a prime mover 16 such as an engine, and pressurizes the pressurized water. After being rectified by the vanes of the diffuser 17, it is jetted from the stern as a high-speed jet stream from the nozzle 18 to obtain thrust.

A seal liner 6 is disposed concentrically with the pump casing 3 in the gap between the outer peripheral surface of the pump blade 1 and the inner surface of the tapered portion of the pump casing 3. This seal liner 6 is the third
As shown in the figure, it is fixed to the liner support plate 8 with bolts 8a. The liner support plate 8 is in contact with the flange portion of the diffuser casing 4 and the flange portion 3a of the pump casing 3.
Is provided so as to be horizontally slidable along the axial direction of the pump casing 3. Further, the support plate 8 has a plurality of rods 10 (for example, 3 to 4) in the circumferential direction thereof.
A plurality of through-holes 3b that are attached to the flange portion 3a of the pump casing 3 and that penetrate in the axial direction are provided at positions corresponding to the attachment positions of the rods 10, so that the rods 10 can be inserted into the through-holes 3b. It extends to the outside of the flange portion 3a.

Then, as shown in FIG. 2, the rod 10 is moved in the axial direction by an external adjusting mechanism 7 provided outside the pump casing 3 to push the liner support plate 8 and the seal liner 6 is moved in the axial direction of the pump casing 3. As a result, the seal gap formed by the outer peripheral surface of the pump blade 1 and the inner surface of the seal liner 6 is adjusted. A seal member 9 for performing a sealing function and a bearing function is fitted to the outside of the flange portion 3a, which is a portion of the flange portion 3a of the pump casing 3 through which the rod 10 is inserted.

Next, the operation of this embodiment will be described.

When readjusting the seal gap formed by the outer peripheral surface of the pump blade 1 and the inner surface of the seal liner 6, as shown in FIG. 4, a blind gap provided at the gap measurement point portion in the circumferential direction of the pump casing 3 is used. The plate 11 is removed by removing the bolts 12, then a separately prepared gap detector 13 is attached to the measurement point portion, and the drive shaft 15 is rotated at a low speed at this gap measurement point to align the outer peripheral surface of the pump blade 1 with the gap. To measure. The amount of movement of the seal liner 6 is determined by the difference between the measured value and the design value. As shown in FIGS. 2 and 3, the seal liner 6 is moved by operating the external adjusting mechanism 7 (manually or with an actuator) to move the liner support plate 8 through the rod 10 by the required movement amount. It is moved horizontally rearward (leftward in the figure) along the axial direction of. As a result, the seal liner 6 attached to the liner support plate 8 also moves in the horizontal direction from the small diameter portion of the taper portion to the large diameter portion by the same amount, and the seal gap is readjusted. Then, when the seal gap readjustment is completed, the external adjustment mechanism 7 is locked, the seal liner 6 is fixed so as not to move, the gap detector 13 is taken out, and the blind plate 11 is attached to the pump casing 3 with the bolt 12. , The work is finished.

As described above, according to the present embodiment, even if the seal gap is widened due to wear, erosion, and corrosion of the pump blade 1, the external adjusting mechanism 7 is adjusted to operate without easily disassembling the main body of the jet propulsion machine. Can be readjusted quickly.

In the above embodiment, the seal gap when expanded due to the wear of the seal gap or the like is returned to the design value, that is, the gap is reduced, but the present invention is not limited to use for readjustment. Can also be applied during the initial assembly of the water jet propulsion machine,
This makes it possible to easily perform the seal gap adjustment work.

〔The invention's effect〕

As described above, according to the present invention, a seal liner that is movable in the axial direction of the pump casing is arranged in the gap formed by the inner surface of the tapered portion of the pump casing and the outer peripheral surface of the pump blade. Since an adjusting mechanism for adjusting the seal gap between the inner surface of the seal liner and the outer peripheral surface of the pump blade is installed outside the pump casing by moving the pump casing in the axial direction, simply by adjusting the adjusting mechanism, The seal gap can be adjusted easily and quickly without disassembling the main body of the water jet propulsion machine. Therefore, it is possible to significantly reduce the cost, time and labor as compared with the case of disassembling and adjusting the main body of the water jet propulsion machine. As a result, the cycle of adjusting the seal gap is shortened, so that the pump performance can be always maintained in a good state, and the thrust can be kept constant without being reduced.

[Brief description of drawings]

1 is a sectional view showing a water jet propulsion device according to an embodiment of the present invention, FIG. 2 is a sectional view showing a pump casing in the same embodiment, and FIG. 3 is an enlarged sectional view showing a pump casing in the same embodiment. FIG. 4 is an enlarged sectional view showing the pump casing in the gap detection state in the embodiment, and FIG. 5 is a sectional view showing a conventional water jet propulsion machine. 1 ... Pump blade, 3 ... Pump casing, 3a ... Flange part, 6 ... Seal liner, 7 ... External adjustment mechanism,
8 …… Liner support plate, 15 …… Drive shaft, 16 …… Motor, 18
……nozzle.

Claims (1)

[Claims] 1. A pump for pressurizing water sucked from the bottom of the ship,
In a water jet propulsion machine that obtains thrust by injecting from a stern nozzle, a seal liner that is movable in the axial direction of the pump casing is arranged in a gap formed between the inner surface of the tapered portion of the pump casing and the outer peripheral surface of the pump blade. And an adjusting mechanism for adjusting the seal gap between the inner surface of the seal liner and the outer peripheral surface of the pump blade by moving the seal liner in the axial direction of the pump casing and installing the adjusting mechanism on the outer side of the pump casing. Water jet propulsion machine.