Fluid power transmission includes a gas (pressure) transmission and liquid transmission, hydraulic transmission into hydraulic transmission, hydraulic transmission and liquid viscous transmission. Special Yu silicone oil fan clutchcalled hydraulic transmission based on the interior market, with the pressure of fluidto pass power; hydraulic transmission based on Euler equation, changes in theliquid momentum short to transmit power; liquid viscous transmission based onNewton inner friction law, the sticky liquid to transfer power.
The basic components of hydraulic transmission is the hydraulic coupling and the hydraulic torque converter. The basic components of hydraulic coupler iscomposed with several radial plane leaves, the working chamber of the pump wheeland turbine. Hydraulic transmission oil in the working chamber in the cycle of high-speed mobile transmission power, oil pumps round her so involved with the campaign because of centrifugal force and centrifugal movement, from the pumpwheel (and input shaft) absorb the mechanical energy into moment of momentum(mVR) increment, high speed fluid flow into the turbine from the pump wheel makes the radial the release of the moment of momentum flow, driving the turbine (andoutput shaft rotation to drive the working machine), (and load) work. The basic components of hydraulic torque converter is a pump wheel, turbine and guide, they are a space (bending) work wheel blades, according to the relevant order form a working chamber. Hydraulic transmission oil is pumped turbine stirred in the working chamber, so that the liquid flow to obtain the moment of momentumincrement, through the guide wheel turned the direction of liquid flow into theturbine after the release, the moment of momentum (kinetic energy) pushes turbines to drive the working machine to rotate.
Hydraulic components of China's rapid development in recent years, the national annual output in 2003 about 70000 sets of hydraulic coupler. Transmission is widely applied to the device for belt conveyor, scraper conveyor, ball mill, fan,compressor, water pump and oil pump etc, improve transmission quality and energy conservation. The maximum output speed of current our country hydraulic coupleris 6500r/min, the minimum power of 0.3kW, maximum power of 7100kW. The development trend of the hydraulic coupler is high speed, high power.
Nien transmission fluid is a liquid driving an emerging discipline, is still at the beginning stage in our country. Because of the liquid viscous transmission products(such as liquid viscosity speed regulation clutch) and hydraulic transmissionproducts (such as coupler) although there are different in nature, but because of asimilar performance and the same purpose (for speed regulation and energy saving), in some technical activities (such as development planning, standards,technology management, order activity) are regarded as the same type, there are common and hydraulic industry, so this one chapter introduces its productsstructure and transmission oil.
Performance characteristics and development, hydraulic transmission oil
Hydraulic transmission oil as working medium not only transfer the power, but alsoused to lubricate the bearing and gear, it is also the carrier of slip hot, take off the heat. Hydraulic transmission oil is a complex and require specialized research topics, which is directly related to the efficiency and the service life of hydraulic components, transmission reliability. Should arouse the attention of extensive in-depth study.
Hydraulic transmission oil should satisfy the following requirements:
1, must have the appropriate viscosity of liquid viscosity is low, showed that theinternal fluid friction is small, the flow resistance loss is small, can reduce thehydraulic loss of hydraulic components; but from the lubrication of the sealing point of view, can not be too low viscosity. Therefore should meet the lubrication andsealing requirements under the premise, as far as possible the use of low viscosityliquid, in order to improve the transmission efficiency of hydraulic components. At the same time requirements for liquid viscosity temperature is better, in order tohigh or low temperatures can still maintain effective lubrication and sealing.
2, a greater emphasis the hydraulic element torque and power and working liquidsevere proportional, so liquid degrees the higher the better.
3, performance is stable and is not easy to produce foam, aging and precipitation.
At present, many kinds of working fluid at home and abroad hydraulic transmissionapplication, in addition to a variety of petroleum based products, but also the use ofwater or other combustible liquids (and the application of coal mine to preventexplosive). Domestic hydraulic components usually with No. 6 hydraulic transmission oil (also useful 8 hydraulic transmission oil), and sometimes replaced with No. 22 turbine oil.
Diesel oil is dedicated to the life of not less than 2000 hours, after initial operation of new equipment installed oil for 100 hours and 500 hours of the first, second formula, can still be used after filtration.
Belongs to one of the following circumstances, need to be replaced with new oil:
When water content is more than 0.2%; the viscosity at 50 DEG C 6 centistokeshigh than new oil; mechanical impurities (benzene insoluble) reached 0.2%; the emergence of acid and alkali or high acid value; effect of bubble too much drivepower. Hydraulic transmission oil except for internal combustion engine vehicle special oil above also have reference value.
Two, liquid viscous transmission on the transmission oil
Liquid sticking transmission according to the operation of oil wax thickness variation can be divided into two categories, one category is in the liquid viscous transmission operation of oil film thickness constant, such as silicone oil fan clutchoil film thickness is fixed, changes in the operational work of the degree of oil filledcavity to adjust the output speed. Another kind is the operation of oil film thickness is variable fluid Nien transmission, this kind of liquid viscous transmission products including liquid viscosity speed regulation clutch, liquid viscous brake, hydro viscous dynamometer, liquid viscous couplings, liquid viscosity speed regulationdevice. The current applications are more liquid viscosity speed regulation clutch,liquid viscosity speed regulation device and a silicone oil fan clutch.
1, liquid viscosity speed regulation clutch and transmission oil
Liquid viscosity speed regulation clutch several oil through its master and slavefriction sheet between the film to the driving power, rely on active friction plate "pull"the driven friction plate rotates in the same direction, oil viscosity, the transmission torque and the oil viscosity and two pieces of "slip" proportional, and the thicknessand oil film (film clearance) into reverse
