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| Analysis of high viscosity gear pump characteristi |
Transmission gear pump is high viscosity liquids better equipment, a wide range of its application.
Currently, in spite of domestic enterprises have produced a lot of high-viscosity liquids suitable for the transmission gear pump, but because of the testing means imperfections in the material selection, leakage and noise control still exist some problems. Domestic particularly high viscosity gear pump efficiency, reliability and service life, with the existence of large gaps between the foreign products. Therefore, China's petroleum and chemical industries using high viscosity gear pump majority still rely on imports.
High viscosity at home and abroad gear pump characteristics of the development are as follows:
Gear structure
High viscosity gear pump gear tooth common with straight, helical gear, herringbone teeth, spiral teeth, tooth profile involute main lines and circular patterns. Usually small gear pump used spur gear, the gear pump often using high temperature change gears, transmission of high viscosity, high pressure melt the polymer melt pump used involute helical gear. Gear and Axle integrated into its rigidity and reliability than single axle gear and the gear pump manufacturer. Foreign low gear pump gear often used a square structure, namely gear tooth width addendum circle equivalent diameter. The use of high-pressure occasion and the high viscosity gear pump gear tooth width is less than its diameter circle, which is to reduce the radial compression gear area, lower gear, bearing the load.
Pump and heating methods
Generally speaking, the pump gear pump more severe shell, its temperature-resistant, ceramic higher. Body material often used ductile iron, cast aluminum hardware can be used Die Casting from, or used aluminum profiles extrusion processing. When the transmission medium is corrosive, may be more costly stainless steel materials. Foreign high viscosity gear pump use of nickel, chromium alloy steel as a high-volume pump shell material, such materials in strength, reliability and cost of comprehensive performance better. To address the storm gear pump oil phenomenon, usually stamped in the pump opened symmetrical unloading trough, or low-pressure side to the direction of asymmetry created unloading bay suction side of a cone unloading bay side of the row of rectangular unloading bay unloading groove depth than in the industrial hydraulic gear pump to be deep.
Due to the high viscosity of the medium transmission gear pump higher viscosity, reduce flow resistance, improve the capacity of pump suction, the media must carry out heating or insulation. Usually electric heating element could viscous liquid heat evenly. If the temperature fluctuation little transmission of high viscosity liquids prone to degradation, recommended fluid heating methods, in particular the emission of gear pump. The fluid is heated internal, external structure. That is the so-called built-in gear pump pump body or cover internal thermal design process sets, is through the external bolts to clip heat pump body kits and linked together. Inner-to the folder into steam, HTF, or cooling water, according to media specific circumstances. Built-in applies to transmission fluid temperature uniformity of higher demand, or request for a uniform high-temperature liquid cooling occasions. When electric heating means lack of security or less demanding right temperature control, can be an external structure. The United States aboard the company's internal gear pump, the pump can be part of the jacket on the transmission fluid temperature control, whether in hot or cold environment, can bring external jacket.
Bearing material, structure and lubrication
High viscosity gear pump bearings usually sliding bearings, and non-load bearing wall surface specially designed spiral flow, spiral groove to the rotation axis steering gear and the same. Bearing pump and the inlet end of the same mouth, bearing side of the spiral groove with the tooth root (vacuum parts) the same. When the rotation axis, with spiral effect and bearing ends of the pressure gradient, bearing external cryogenic liquid inhalation bearings, lubrication of the bearings and cooling, the inflow has undocked from the meshing teeth, constitute a full lubrication, cooling fast spiral of self-absorption of low pressure lubrication system. The lubrication method's advantages are: the bearing lubrication all cryogenic liquid medium, viscous liquid lubrication easy carrying capacity of a strong dynamic pressure film. A lot of lubricating fluid circulating constantly bearing away the heat, a good pair of bearing lubrication and cooling。 With sufficient liquid to fill emerging from the meshing tooth roots, has greatly improved since the gear pump suction performance, avoid the suction air phenomenon, it can not only improve volumetric efficiency, but also help reduce cavitation and reduce noise. Sichuan Machinery Research and Design Institute will be used in the sliding bearings soaking in the media and through special channels forced lubrication, the technology has vinylon, polyester, rubber, resins, fertilizers and other areas Gear Pump successful application.
If the transmission medium of wear particles should be used incompetent bearing materials, such as ceramics. In recent years, GS-1 PTFE composite steel is considered ideal sliding bearing materials. It consists of cold-rolled thin plate (matrix), spherical porous sintered bronze powder or copper network (middle layer), polytetrafluoroethylene (surface layer) from the three-tier composite materials, both metal and plastic PTFE advantages. In this material on the basis of the Shanghai Institute also developed a better performance of three-SF Self-lubricating composite materials, to replace bronze silk bronze powder layer, the surface of plastic formula has been carefully screened. Bearing this material fatigue resistance, high load-bearing capacity, coefficient of friction, long service life, gear pump technology is to improve performance of new bearing materials.
Pai oil suction mouth
High viscosity gear pump suction mouth diameter of more general, sometimes by the proliferation of mouth-shaped suction to expand the volume of low pressure to reduce import liquid flow, reducing the pump suction fluid resistance. Such structures can also reduce the role of the Journal and the radial force on the bearings, extending high viscosity gear pump life.
Safety valve and check valve
The output of the gear pump installation of a check valve on, in this pump and export pipeline maintenance, the system will not turn the clock back in the liquid; Gear Pump-load stopping, in its output produced partial vacuum inside the tubes to prevent pump reverse. High viscosity gear pump exports of the road and also set up a safety valve to protect installations, so once the pump outlet to plug in, we can open the safety valve relieving. Safety valve and the pump body or pump can be covered cast one that can separate assembly. |
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NO.158 Bonan Road
Botou City,Hebei Province,China. |
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062150 |
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0086-22-58292649 |
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0086-22-58292663 |
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