| The internal-combustion engine of large and medium mountain-agriculture-machinery will produce a lot of heat in the working.The engine is working in different road conditions and working conditions,the heat by engine generating have change greatly in the poor working environment of agricultural machinery.The fluctuations of engine’s operating temperature under the complex working conditions will reduce the life of the engine and even cause damage to the engine.To overcome this problem,this title using shape memory alloy with both temperature and driving characteristics to be made of shape memory alloy temperature control switch and the perception of temperature change;and magneto-rheological fluids which can produce yield stress under magnetic field are used as transmission medium to transfer power.Permanent magnet generator technology is used in the transmission process,and generator’s self-generation electricity under the engine’s motivations supply power for the entire agriculture mechanize.The transmission system of self-generation electricity can realize intelligent start and stop and can self-adaptive controlling speed according to change of environmental temperature,and as a power which can self-generator electricity supply power for the entire agricultural machinery.The shape memory alloy temperature-control electricity switch which resistance can change and adaptive adjustment with the vary of environmental temperature is designed by combining circuit Ohm’s law and method of mechanical design and based on sensing temperature and driving characteristics of shape memory alloy.The temperature-resistance of temperature control switch can adaptive change under different temperature conditions and change the current through the temperature detect switch indirectly.The relationships of temperature detect switch of stroke and resistance and resistance wire’s designing formula was established based on the Ohm’s law relation.The theory of shape memory alloy spring was analyzed and design formula of shape memory alloy spring was introduced according to the design formula of ordinary helical spring.The shape memory alloy temperature detect switch are calculated according to the data given in the design’s case,results show that: shape memory alloy spring output stroke was nonlinear increase with increasing of temperature,temperature control switch resistance values was nonlinear decreasing with temperature increasing.The test experiment of driving characteristics of shape memory alloy spring was design based on temperature sensing and driving theory of shape memory alloy.The experimental results show that: the output displacement of shapememory alloy spring increased with the increasing of temperature.The theoretical values are consistent with the experimental values.The shear flow of magnetorheological fluid in the two disc was analyzed based on the Bingham model of the magnetorheological fluid.The relationship’s expression of transmission system of self-generation electricity of output torque and output speed was established.The disk-type magnetorheological fluid clutch was designed and the key size and the key parameters of the magnetorheological fluid clutch was calculated based on maximum torque principle and circuit design principle.The theoretical data and the simulation of data which simulation analysis of the magnetic circuit used by ANSYS software was analyzed,and the design theory is correct in the range of error.The rate of magnetic saturation evaluation is proposed based on magnetic saturation analysis and evaluate magnetic saturation condition of magnetorheological clutch,the results show that:magnetorheological clutch did not reach magnetic saturation in meeting condition of working,namely the designing of size and the current is reasonable.The working principle and various parameters in the permanent magnet generator was introduced and the design theory of permanent magnet generator was analyzed.The permanent magnet generator was designed according to the design formula. |
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