Hydraulic pressure expander

Abstract

The invention discloses a hydraulic pressure expander, comprising a reversing valve, a seawater or freshwater hydraulic cylinder or an expanding mechanism which are connected in sequence, wherein thereversing valve controls the hydraulic cylinder to expand and retract; hydraulic cylinder realizes expansion and traction by telescopically driving expanding arms to expand; the reversing valve is a three-position four-way structure; the contacting form of a valve core and a valve seat of the reversing valve adopts a floating structure; under the effect of pressure of a spring, the valve core andthe valve seat are contacted reliably all the time, the gap after being worn can be compensated automatically, and the sealing reliability and service life are greatly improved. The hydraulic pressureexpander adopts seawater or freshwater as working medium, is characterized by high efficiency, large operating depth, convenient operation and good environment compatibility, not only can be used foroperation of underwater expansion, clamping and the like, but also can be used for fighting fire on land, rescuing emergency and saving lives.

Description

technical field [0001] The invention relates to an underwater working tool, in particular to a hydraulic expander used in oceans or freshwater lakes. Background technique [0002] The hydraulic expander is a large-scale salvage device driven by hydraulic pressure, which can provide a large expansion force and is used to expand heavy objects such as reinforced concrete and stone slabs. It is mainly suitable for underwater operations in oceans, inland rivers, and lakes. It can also be used for Firefighting, emergency rescue and disaster relief and other industries. [0003] At present, the hydraulic expander products on the market are all hydraulic products. When used in underwater operations, the land-use hydraulic expander is modified to a certain extent. Although hydraulic tools have high working pressure and high power density, etc. Advantages, but due to the characteristics of the oil medium itself, the oil pressure expander will have the following problems when it is us...

AI Technical Summary

Problems solved by technology

[0004] 1) Hydraulic oil and water are incompatible. When hydraulic oil leaks into water, it will cause environmental pollution. When water seeps into the hydraulic system, it will cause corrosion and functional failure of components, thereby reducing the reliability of tools;

[0005] 2) The viscosity of hydraulic oil is high, and its viscosity-temperature and viscosity-pressure coefficients are large. With the expansion of operating depth and scope, the pressure loss along the oil inlet and return pipes of the system increases significantly, and the tool efficiency decreases significantly;

[0006] 3) The oil pressure expander and the power source must be designed as a closed system. When it is used for large-depth operations, a pressure compensation device must be added, thereby increasing the volume, weight and complexity of the equipment, and reducing the reliability and reliability of the system. maintainability;

[0007] 4) The oil pressure expander and the power source must be connected by two hoses, the oil inlet and the oil return, so the force of the wind, waves and sea current is strong during underwater operations, which greatly interferes with the operation of divers;

[0008] 5) It is not possible to directly replace the operating tools underwater, or perform simple maintenance, and the adaptability of the tools is poor

[0010] 1) Leakage problem, since the viscosity of water is only about 1 / 30 to 1 / 40 of that of oil, therefore, under the same pressure, the leakage flow through the same sealing gap is much larger than that of oil, about 20 times

[0011] 2) Corrosion problems. Water, especially seawater, is highly corrosive. Because seawater contains a large amount of organic matter, microorganisms, metal and non-metal ions, and the salt content in seawater is 3.2-3.75, the amount of chloride ions is large, and seawater is natural. Electrolyte, so it has a strong corrosive effect

[0012] 3) Cavitation problem, due to the high vaporization pressure of water (about 0.0023MPa at 20°C, about 0.012MPa at 50°C), which is tens of millions of times higher than ordinary hydraulic oil, and is particularly prone to cavitation

Cavitation causes metal peeling and roughness on the surface of the component, and the working life of the component is reduced

[0013] 4) Wear problem, due to the poor lubricating performance of the water medium, it is difficult to form a liquid lubricating film on the counter surface of the friction pair, and it is also impossible to form a good-strength boundary film, so it is easy to cause dry friction, aggravate the wear speed of hydraulic components, and cause failure

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