JPH0615830Y2 - Marine Propeller - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a marine composite propeller in which a screw propeller and a pump jet propeller are arranged side by side on the same axis.

[Conventional technology]

The conventional marine propellers have been considered to have a main condition that they efficiently change the given power into a propulsion force to enhance the propulsion efficiency, have sufficient strength, and prevent damage due to cavitation. .

However, recently, with the progress of underwater acoustic technology, it has been highlighted that the underwater radiated noise of a propeller becomes a serious obstacle to this underwater acoustic technology in some ships.

Each equipment installed on a ship has its own vibration and noise reduced, as well as a significant reduction in underwater radiated noise due to various vibration and sound insulation technologies already prepared, and in some cases, its level is reduced in advance. Is becoming predictable.

On the other hand, in the case of marine propellers as well, due to the progress of design technology due to its own noise reduction, low rotation and large diameter, increase in number of blades, skew blade, prairie (air is jetted from the blade leading edge portion), double Inverted propellers, idler propellers, and further improvements in propeller inflow conditions from the hull side were introduced, and some improvements have been made. But,
Along with the times, along with the fact that the direction of increasing the horsepower of the propeller is unavoidable and it is forced to operate directly in water, it is difficult to apply vibration and soundproofing technology like other equipment, Usually the largest source of noise.

Here, the above-mentioned free-running propeller considered to be prior art similar to the marine composite propeller of the present invention (see, for example, Japanese Patent Laid-Open No. 62-261).
590) and double reversal propellers (see, for example, Japanese Utility Model Laid-Open No. 61-185700 and Japanese Patent Laid-Open No. 57-160794), a simple comparison with an ordinary screw propeller is shown in FIG. 5 (a). Let's try based on (b) and (c). To facilitate this comparison, the diameters of the three thrusters are equal, D. This is because the maximum propeller diameter that can be attached to the hull is generally decided when the hull is decided, but when aiming at a high efficiency or low noise propeller like this time, this maximum diameter is always adopted. is there.

Idle propeller 35A shown in FIG. 5 (b), the front propeller 35 is driven by the main engine, the rear of the rotor 36 is working part D _o contained in the wake of the front propeller 35 as hydraulic turbine, D _o The outer part of is functioning as a propeller. At this time, from the front propeller 35 to the rear rotor 36
Transmission of power to the engine is performed through a kind of fluid coupling, but since the efficiency of the fluid coupling cannot be 100%, the efficiency of the ordinary propeller 34 in FIG. Inferior to.

Further, the rotation speed of the rear rotor 36 is considerably lower than the optimum rotation speed of the ordinary propeller 34.
In order to do work comparable to, it is necessary to operate with a higher circulation density distribution or thrust coefficient. For this reason, in particular, tip vortex cavitation, which is involved in the beginning of cavitation, is expected to occur earlier. Although multi-blades have been attempted as a countermeasure, if the normal propeller 34 is multi-bladed as well, it will not be possible to obtain an inherent gain. That is, it is considered that the idler propeller 35A is inferior to the normal propeller 34 in terms of efficiency and noise. Fifth
The double-inverted propeller 37A in FIG.
And the rear propeller 38 are rotationally driven in opposite directions. Therefore, since the absorption horsepower of one propeller becomes 50%, lower rotation and larger diameter can be achieved to improve efficiency, and the swirling flow component flowing out from the front side is collected by the rear side propeller 38. Since it contributes to the efficiency, it can be expected that the efficiency is improved by about 10% as compared with the ordinary propeller 34. However, the diameter D ₁ of the rear side propeller 38 is determined according to the contraction of the wake of the front side propeller 37, and because of the small diameter and the inflow of the water flow accelerated by the front side propeller 37. In particular, the cavitation conditions of the front propeller 38 are strict and it is not always easy to reduce noise.
The result is inferior to 4.

As described above, the idling propeller and the double reversing propeller are inferior to the conventional screw propeller in terms of noise, and are at a level that is not so different.

On the other hand, there is a pump jet propulsion device that can significantly reduce the underwater radiation noise of the propulsion device. This also causes water pressure generated by a pump mounted in the duct to be ejected from the nozzle and generate thrust by its reaction force. This reduces cavitation, which plays the most important role for underwater radiated noise, and it works because the pump is enclosed in a duct. However, since the propulsion efficiency of the pump jet propulsion device is significantly inferior to that of the conventional screw propeller, its adoption is restricted.

[Problems to be solved by the device]

By the way, ship types that require the most reduction of underwater noise of a propulsion device are ships and ocean observation ships.For example, in the case of ships, there are low-speed, medium-speed, and high-speed navigation modes, of which It is an important theme to expand the medium speed range to cavitation free, that is, to the high speed range with low noise. On the other hand, a highly efficient propulsion device is required to increase the cruising range and obtain high speed power.

However, none of the above-mentioned conventional propulsion devices can simultaneously satisfy such a demand.

Therefore, the object of the present invention is to provide a marine composite propeller in which a most efficient propulsion method can be selected according to the operation situation by combining a high-efficiency conventional screw propeller and a low-noise pump jet propeller. To do.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the composite propeller for a ship according to the present invention is, in the first devised configuration, driven by arranging a screw propeller on the front side of the stern and a pump jet propulsion device on the rear side thereof on the same axis in parallel. The propeller shaft is a hollow shaft, the drive shaft for driving the pump jet propulsion device is inserted into the hollow propeller shaft, and the propeller shaft and the drive shaft are connected to one or more main engines via gears and clutches, respectively. In the second invention configuration, the screw propellers are arranged in front of the stern in the stern and pump pump propulsion units are arranged in parallel on the same axis in the rear of the stern, and the shafts for driving the screw propellers are provided with gears and clutches. A shaft for driving the pump jet propulsion device is arranged in the guide vane boss while being connected to the main engine via the drive shaft. The transmission shaft engaged with the main engine is connected via a clutch.

[Action]

In any of the above configurations, when low noise is required, the pump propeller propels the screw propeller to idle, and when cruising distance is required, the screw propeller propels the pump jet propeller to idle. It is possible to select the most suitable propulsion method according to the operating situation, such as turning the wheels and driving both at the same time when high speed is required.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a partially cutaway side view of a stern part showing a first embodiment of the present invention, FIG. 2 is a main part view when one main engine is used, and FIG.
FIG. 4 shows a second embodiment in which the pump jet propeller is a variable pitch propeller, and FIG. 4 is a third embodiment in which the screw propeller is a variable pitch propeller.

In FIG. 1, 1 is a hull, and 2 is a rudder, which is normally arranged behind a propulsion device.

Reference numeral 3 denotes a screw propeller arranged on the front side of the stern, which maintains high efficiency with a conventional type propeller. When low noise operation is required, the propeller 3 on the front side is left idle, but the propeller 3 is operated at a load level that does not cause cavitation, and the remaining necessary power is entrusted to the pump jet propulsion device 4 described later. Etc. are operated.

Reference numeral 4 denotes a pump jet propulsion device which is arranged behind the screw propeller 3 and on the same axis as the screw propeller 3. This pump jet propulsion device 4 is basically a kind of axial flow or mixed flow pump, and water coming out from an impeller 10 described later is converted into pressure by the guide vanes 11. This is discharged as a high-speed jet by the nozzle (duct) 13, and thrust is generated by its reaction force. The tip vortex cavitation, which is the first problem in the case of the screw propeller 3, is structurally unlikely to occur in the pump jet propeller 4, and is increased in the wake of the impeller 10 so that the cavitation tends to disappear, and at the inlet. Since it is operated in a more controlled state in the duct, such as in a more rectified state, the occurrence of cavitation itself is originally small, but since the place where it occurs is in the duct,
It is difficult to emit noise to the outside. Therefore, it is used when low noise operation is required. The pump jet propulsion device 4 is inferior in efficiency to the screw propeller 3, but by arranging both of them on the stern and the bow, the space limitation is solved and the pump jet propulsion device 4 is installed after the screw propeller 3. It is arranged on the flow side to reduce the drag resistance. As will be described later, each propulsion device is configured so that it can be driven independently or simultaneously.

A propeller shaft 5 supports and drives the screw propeller 3. The propeller shaft 5 is a hollow shaft and includes a drive shaft 15 that drives the pump jet propulsion device 4.

Reference numeral 6 denotes a gear, which is integrally engaged with the propeller shaft 5 and drives the propeller shaft 5. A pinion 7 is engaged with the gear 6 to drive it. Reference numeral 8 denotes a clutch, which controls the engagement and disengagement of the power transmission of the main engine 9 described below, and keeps this in the disengaged state during low-noise operation to allow the screw propeller 3 to idle.

A main engine 9 is a gas turbine, a diesel engine, or the like. In ships, the former is particularly important because of its light weight and low vibration.

Reference numeral 10 denotes an impeller, which is shown in the shape of an axial flow pump in the figure, but may have a mixed flow pump shape. Reference numeral 11 denotes a guide blade, both ends of which are fixed to a guide blade boss 12 and a duct 13 described below, respectively, and converts the water flow coming out of the impeller 10 into pressure. Reference numeral 12 denotes a guide blade boss, which is configured integrally with the guide blade 11 and plays a role of supporting the drive shaft 15 of the impeller 10. 13 is a duct,
The impeller 10, the guide vane 11, and the guide vane boss 12 are included, and the rear end thereof functions as a nozzle for ejecting a pump jet.

Reference numeral 14 denotes a strut, which is configured to finally support the guide vane boss 12 from the hull 1 via the duct 13 and the guide vane 11, and to support the impeller 10.

Reference numeral 15 is a drive shaft that supports and drives the impeller 10 as described above, and is contained in the propeller shaft 5. Reference numeral 16 denotes a bearing, which transfers the weight of the screw propeller 3 to the drive shaft 15 through the bearing 16 and supports the drive shaft 15. Reference numeral 17 denotes a gear, which is integrally engaged with the drive shaft 15 and drives it.

Reference numeral 18 is a pinion, which engages with the gear 17 and drives it. Reference numeral 19 denotes a clutch, which controls engagement and disengagement of power transmission of the main engine 20 described below, and keeps the impeller 10 idle during high efficiency operation. A main engine 20 is a diesel engine, a gas turbine or the like.

The embodiment shown in FIG. 1 shows the case where two main engines 9 and 20 are provided, but as shown in FIG. 2, this may be one. That is, as shown in FIG.
Even the clutches 8 and 19 have the same configuration as in FIG. 1, and the clutches 8 and 19 may be configured to reach one main engine 26 via the drive gears 21 and 23, the idle gears 22 and 24, and the drive gear 25 on the upstream side thereof. Good.

According to the above configuration, the two propellers (screw propeller 3 and pump jet propeller 4) are independent of the main engine 9, 2
0 (or 26) can be driven, but when these two independently propelled propellers are used in combination according to their purpose, for example, when two propellers are used simultaneously and when they are used independently. The optimum pitch of each thruster is not necessarily the same when used in. For that purpose, a configuration in which a variable pitch propeller is used so that the pitch of each propulsion device can be freely converted is shown in FIGS. 3 and 4.

The second embodiment of FIG. 3 shows a case where the pump jet propeller 4 is a variable pitch propeller. In this case, the entire structure is the same as that shown in FIG.
0 ', the drive shaft 15 is hollow, and the control mechanism 2
7 is added, and the structure of a normal variable pitch propeller is simply added. Variable pitch propeller 1
If the vehicle can be driven to 0'in reverse, the propulsion system can be moved forward or backward without equipping the main engine or the speed reducer with a special device.

The third embodiment shown in FIG. 4 is a case where the screw propeller 3 is a variable pitch propeller 3 ′, which is the same as the conventional variable pitch propeller equipped ship without the pump jet propulsion device 4, and has a bulge bearing 28. Is supported on the hull 1 via struts 29, and is driven by the main engine 9 via the hollow propeller shaft 5 supported by the bearings 28. 27 'is a control mechanism. On the other hand, in the pump jet propulsion device 3, the drive shaft 30 is arranged in the guide vane boss 12, and is connected to the main engine 20 via the bevel gears 31 and 33 engaged with the drive shaft 30. Three
Reference numeral 2 is a transmission shaft that connects the bevel gears 31 and 33 provided in the strut 14.

In the above configuration, the optimum propulsion method can be selected according to the operating state of the ship. For example, as described above, in the case of a ship that most needs to reduce the underwater radiation noise of the propulsion device, its navigation mode is divided into low speed, medium speed, and high speed. Is required to be expanded to the high speed range with low noise. On the other hand, since a high-efficiency propeller is required to increase the cruising range and obtain high-speed power, it is possible to reduce the output required to cover the medium-speed range in order to satisfy these requirements. The propelling method is such that the pump jet propeller absorbs the remainder and the conventional screw propeller absorbs the rest. Then, basically, each propulsion device is configured so that it can be driven independently and simultaneously, so when low noise is required, it is propelled by the pump jet propulsion device to allow the screw propeller to idle, and When a distance is required, the propeller is propelled by a screw propeller to idle the pump jet propeller, and when high speed is required, both are operated simultaneously. This makes it possible to satisfy the necessary conditions as much as possible.

[Effect of device]

As described above, according to the present invention, it is possible to operate with less noise than a conventional screw propeller or a double-reversal propeller or a free-running propeller derived from it. With the combined propeller of the present invention, the advantages of both propulsion units can be brought out, and in particular, the low efficiency of the pump jet propulsion unit can be covered by the screw propeller, which is the optimum propulsion method according to the operating conditions of the ship. Can be selected. Also,
Two propellers are installed side by side on the same axis to eliminate space restrictions and reduce drag resistance of the pump jet propeller.

Assuming now, 1/3 of the required output to the pump jet propulsion device
If you take charge, the screw propeller will be 2/3, and with the same diameter, the screw propeller can be rotated at a lower speed (about 87%) than conventional, it is low noise, high noise. This can further contribute to efficiency improvement.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of a stern part showing a first embodiment of the present invention, FIG. 2 is a main part view when one main engine is used, and FIG.
FIG. 4 is an explanatory diagram of the second embodiment when the pump jet propeller is a variable pitch propeller, and FIG. 4 is an explanatory diagram of the third embodiment when the screw propeller is a variable pitch propeller. FIG. 5 (a) (b) (c) is a comparative diagram of a conventional screw propeller, idle propeller and double inversion propeller, respectively. 1 ... Hull, 2 ... Rudder, 3 ... Screw propeller, 4 ... Pump jet propeller, 5 ... Propeller shaft, 6 ... Gear, 9, 20, 26 ... Main engine, 8, 19 ... Clutch, 10 ... Impeller, 11 ... guide vanes, 12 ... guide vane bosses, 13 ... ducts, 15 ... drive shafts.

Claims (2)

[Scope of utility model registration request] A propeller shaft for driving a screw propeller is a hollow shaft, and a pump jet propelling device is provided in parallel with a propeller shaft behind the screw propeller on the front side of the stern. A marine composite propeller in which a drive shaft for driving a propulsion device is inserted, and the propeller shaft and the drive shaft are connected to one or a plurality of main engines via a gear and a clutch, respectively. 2. A stern of a stern in which a pump propeller is installed in parallel behind the screw propeller and its rear, and a shaft for driving the screw propeller is connected to a main engine through a gear and a clutch, and A marine composite propeller in which a shaft for driving a pump jet propulsion device is arranged in a guide vane boss, and a transmission shaft engaged with the drive shaft and a main engine are connected via a clutch.