CN1338413A

CN1338413A - Method for increasing efficiency of helical propeller

Info

Publication number: CN1338413A
Application number: CN 01119407
Authority: CN
Inventors: 佟宪良
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-05-23
Filing date: 2001-05-23
Publication date: 2002-03-06

Abstract

A method for increasing the efficiency of helical propeller of ship is disclosed. It features that the introduced air replaces cavitation. As the pressure of introduced air is higher than that generated by cavitation, the air bubbles are eliminated resulting in higher efficiency, high rotation speed, smaller diameter of propeller and higher water quality (low BOD and COD numbers).

Description

A kind of method that improves efficiency of helical propeller

The invention belongs to boats and ships spiral pushing device method field of manufacturing.

The spiral pushing device of current boats and ships is for soaking oar entirely, partly soaking oar and cavity oar and supercavitation oar, the shortcoming of these spiral pushing devices is: when cavitation takes place at the blade back side, then the pressure of fluid can hang down so that form critical vacuum state on the position of cavitation, promptly produces cavity.When these cavitys are crumbled and fall, the local pressure of water changes blade generation reverse impact, cavity causes screw propeller damage, vibration and mis-behave, and the high speed oar usually is designed to be in work under the full cavity state, but follow cavitation to produce following problem: cavity is flowing to the oar rear portion when crumbling and fall, for degrading of below adjacent blades or oar bracing strut, rudder for ship, ship surface.In addition, the closure of cavity can cause cavitation noise and vibration.

The object of the present invention is to provide does not a kind ofly have cavity, oar is not had reverse impact power, degrading when no cavity is crumbled and fall, no cavitation erosion and can increase work efficiency and the manufacture method of the spiral pushing device of working speed.

This method imports gas to screw propeller blade back and generation cavity zone, and then the method for elimination cavity, concrete grammar is: to screw propeller axle sleeve open walk, and importing gas can connect air, also can insert through post-decompression, be enclosed in that no burn in the molten device of sealing load does not burn, inexplosive other gas, can also be to pass through the gas that supercharging equipment compressed, or pass through the exhaust of the driving engine after cooling, the filtration.Make gas enter the oar axis channel by perforate road on the oar axial wall, enter propeller hub by unidirectional non-return valve, gas is passed through and corresponding blade back position, the through hole road of opening on oar axle and propeller hub enters the oar back of the body, the oar back of the body along the blade limit, ring limit and other parts back, open the duct respectively, the road junction correspondence is open-minded therewith to make on the propeller hub duct, make gas enter oar back of the body passage, on the oar back of the body passage cover plate is arranged, have vertical channel on the cover plate, make gas from the duct, arrive the oar back of the body, and the cavity zone takes place, and then the elimination cavity, the gaseous tension of importing is directly proportional with the raising of efficient.

Because adopted the present invention to eliminate cavity to import gas, gas is that the negative pressure that blade back produces when working owing to screw propeller imports, because the blade back fluid pressure height when the blade back fluid pressure is than the generation cavity behind the importing gas, therefore importing gaseous tension is the pressure that is better than cavitation, import the generation that the gas oar is eliminated cavity thereby make, and improved the working speed of spiral pushing device, import the zone that cavitation promptly will take place along with the gas on the blade, at this moment the gas that is imported can be eliminated the cavity that will the take place phenomenon that crumbles and fall fully, different with cavitation phenomenon is: cavitation has produced the cavity of critical vacuum, and import gas is that malleation can not crumble and fall, make will cavitation the zone reduced negative pressure, not only do not reduce but also improve so the working speed of oar is raised the efficiency.The state of streaming that state and supercavitation oar are streamed in the surface that import the gas blade this moment has similarity, but littler than supercavitation oar power consumption, and has eliminated cavity crumble and fall vibration that phenomenon brings, surface deterioration and noise under water.

When existing screw propeller was worked behind ship, the water sorption of oar increased the stern water velocity, according to the bernoulli theorem, flow velocity increases then pressure decay, thereby the increase of stern water velocity will cause the redistribution of stern pressure, the reduction of afterbody pressure, stem pressure is constant, and ship has increased extra resistance.In addition, because the afterbody flow velocity increases, friction drag also increases, screw propeller work to the influence of ship mainly is like this, the stern water flow velocity increases, and mainly is that the overall resistance of ship is increased to the influence of ship, and the displacement that imports the gas after screw reduces relatively, also just reduced hull resistance, friction force have been improved the efficient of whole ship.

Advantage of the present invention and good effect are:

1, because the elimination of cavity improves efficient, increased the flying power of boats and ships;

2, because the elimination of cavity improves the working speed of spiral pushing device, thus can deduct the deceleration tooth case between driving engine and the screw propeller, and the diameter of screw propeller is reduced, saved material, alleviate weight, reduced cost, used the hull space again less;

3, help to eliminate cavity because import increasing of gaseous tension, so the pressure that imports gas is directly proportional with raising the efficiency;

4, because the elimination of cavity can not make the propeller efficiency that improves rotating speed descend, can when improving rotating speed, raise the efficiency on the contrary;

5, because the elimination of cavity, the screw propeller working speed is improved, so under the power boosting equal-wattage, diameter of propeller reduces, so owing to the moment of torsion that reduces axle of oar diameter reduces, diameter reduces, saved material and since the oar diameter reduce ship is reduced the requirement in navigation channel, increase the navigation ability, make the harbour of little tonnage stop large-tonnage ships, the cost of building harbour is reduced;

6, because the elimination of cavity under the condition that does not reduce efficiency of helical propeller, is improved the speed of boats and ships;

7, because the importing of air increases the waters dissolved oxygen amount of navigating, the BOD in the water, COD value have been reduced;

8, the oar after the employing patent of the present invention, every technical index all is better than surperficial oar.

Description of drawings:

Fig. 1, being main pseudosection, Fig. 2, is the local amplification view of screw propeller, Fig. 3, be blade structure for amplifying cutaway view, and Fig. 3-1 be that Fig. 3,90 spends and rotates main pseudosection;

A is an air intake, and a ' is the working gas inlet, and b is an oar axle sleeve open channel, c is an oar axle perforate passage, and d is an oar axle open channel, and d ' is an oar axle mounting screw propeller end passage, e is unidirectional non-return valve, and f is the open channel of oar axle and the corresponding blade back of propeller hub, and g is the blade back side, h is the cover plate screw, and l is a suction hole, and n is that to lead to blade back be air flue to gas, o is the air flue cover plate, x is a propeller hub, and y is the oar key, and z is the groomed oar shaft section.

To most preferred embodiment of the present invention, do following explanation in conjunction with the accompanying drawings:

The present invention is by the screw propeller axle sleeve is opened duct b, and imports gas and make gas should be higher than the boats and ships water line by opening a ' and a ', enters axle sleeve through passage b, by perforate passage c on the oar axial wall.Non-installation oar side oar axle can be solid axle to limit, c hole, use full groomed oar axle locate to shut at c ', each duct c area sum is more than or equal to the sectional area in oar axis hole road, make gas enter hole c, with oar axle center open walk d, and enter d and make gas through unidirectional non-return valve e, enter oar axis channel d ', and by the corresponding blade back of d ' arrival propeller hub position, the passage f that opens on oar axle and propeller hub enters the oar back of the body, by oar back of the body open walk n, enters the vertical suction hole l of oar back of the body passage upper cover plate, make gas final blade back side that arrives from the duct, and then eliminate cavity.

Utilize method of the present invention, can transform the superannuated ship oceangoing ship, design new boats and ships.

Claims

1, a kind of method that improves efficiency of helical propeller is characterized in that: import gas to screw propeller blade back and generation cavity zone, and then eliminate the method for cavity;

2, it is characterized in that according to the described a kind of method that improves efficiency of helical propeller of claim 1: make air pass through air intake (a), enter screw propeller axle sleeve open walk (b) via going into gas port (a '), and make gas pass through (c) on the oar axial wall, enter oar axle center open walk (d), make gas enter oar axle mounting screw propeller end passage (d ') by unidirectional stop valve (e) via the duct, enter the corresponding blade back of propeller hub again along the blade limit, the duct is evenly opened at ring limit and other parts back respectively, the through hole road (f) that the opening of the channel position is opened on oar axle and propeller hub enters the oar back of the body, by oar back of the body open walk (n), enter the oar back of the body vertical suction hole of passage upper cover plate (1), make gas from the duct, arrive the whole back sides of oar, and then eliminate cavity;

3, according to the described a kind of method that improves efficiency of helical propeller of claim 1, it is characterized in that: the gaseous tension of importing is directly proportional with the raising of efficient;

4, according to the described a kind of method that improves efficiency of helical propeller of claim 1, it is characterized in that: by the gas access can insert through post-decompression, be enclosed in that no burn in the molten device of sealing load does not burn, inexplosive other gas, can also be the gas that compressed through gas boosting equipment, or through the engine exhaust after cooling, the filtration;

5, according to the described a kind of method that improves efficiency of helical propeller of claim 1, it is characterized in that: deducted deceleration tooth case after having improved the working speed of screw propeller, the oar diameter reduces when having improved behind the propeller speed with power;

6, according to the described a kind of method that improves efficiency of helical propeller of claim 1, it is characterized in that: increase the area of air intake (a), enter gas access (a ') by conical pipeline;

7, according to the described a kind of method that improves efficiency of helical propeller of claim 1, its special sheet is: be provided with unidirectional non-return valve in the groomed oar axis channel, non-installation oar side oar axle is thought solid axle to (c) Kong Bianke.