| The working principle of magnetorheological transmission device based on magnetorheological fluid as working medium, the power and motion forms is to rely on two transmission interface between MRF to deliver, by adjusting the current size of the electromagnetic coil, to control the intensity of the magnetorheological effect, realize the MRF shear stress stepless adjustment. Magnetorheological transmission as a new form of power transmission, it not only has convenient control, low energy consumption, fast reaction (millisecond level), change of the external environment have little influence on the characteristics of MRF. Therefore, magnetorheological transmission technology is widely used in machine transmission parts of the execution part of stepless speed regulation, overload protection, mechanical and electrical equipment of soft start and soft brake, etc. In view of the present research of magnetorheological transmission technology both at home and abroad, this paper study the following several aspects.1. To establish the shear mode magnetorheological fluid force calculation model between the layersAnalysis and calculation the stress of ferromagnetic particles in the chain using the classic dipole model, local dipole model and finite element model respectively. And comparison of the three kinds of model, according to the experimental contents of this paper, establish the shear mode magnetorheological fluid force calculation model between the layers.2. To design transmission force characteristics of MRF between the layer in shear modeAnalyzed three kinds of coil arrangement (external type, coil built-in coil, coil set type) and three drive forms (disk drive, cylinder, cylinder drive), choose the coil arrangement is external coil type, transmission form for disk drive; Comparison the advantages and disadvantages of the two kinds of heating methods (heating box, aluminum heater heating), choosing heating way for aluminum heater heating; Given the basic structure of the magnetic circuit, analysis and determine material in the paragraphs of magnetic circuit, the number of ampere turns coil is 1025A by the calculated, number of turns of the coil is 2050n, the electromagnetic coil cross sectional diameter is 0.8mm by calculate, the average number of turns per unit length is 11-9n/cm, average per unit thickness layers.is 10.87n/cm3. To establish the simulation model of The transmission force characteristics of MRF between the layer and simulation of magnetic fieldAccording to the basic requirements of the experiment, we give the simulation conditions, establishing simulation model of MRF force characteristics research device of inter layer, analysis the magnetic field distribution of the device. Placed the probe in different positions of MRF space Respectively during the process of the simulation analysis when simulated, and the position of the magnetic field distribution were analyzed. 4. To set up and test transmission force characteristics of MRF between the layer in shear modeGiven the structure schematic diagram and the real figure of The transmission force characteristics of MRF between the layer in shear mode, from the Angle of graphics intuitively shows the internal composition of each module and the relationship between them; Manufacturing and building experiment device, to design experiment contents and steps, study on the wheel at different positions, and for each position of the three variables to block experiments, then obtain data.5. The experimental results and its analysisIn composite composed of magnetic field and temperature field test transmission force characteristics of magnetorheological in the different layer under shear mode, and set up magnetorheological inter layer force characteristic curve in shear mode, and combined with theoretical analysis, under the condition of the ferromagnetic particles reach uniform magnetization, the shear yield stress between the layer output characteristics into a symmetrical distribution, the plane of symmetry is MRF in space along the height direction in the middle of the plane, forming MRF shear yield stress of the rotary table location characteristic curve that higher in the middle to both ends to reduce, and combining theoretical analysis with the result of the experiment analysis of debate:By three theoretical model results shows:under the effect of weak magnetic field, the dipole boundary theory model calculation results with the experimental values of minimum error, between -1.5%-1.5%, shows that the experimental value fluctuate; Local field dipole theory model calculation results with the experimental value of the error range between 2.5% and 4%, shows that the theoretical value is greater than the experimental value in general; Derived from the classical theory of dipole model calculation value and experimental value of the error range between -2.5%-1%, shows that the experimental value fluctuates up and down, and fluctuation range is larger.Under the effect of strong magnetic field, the boundary by dipole theory model calculation results with the experimental value of the minimum error, between - 0.4% 0.4%, shows that the experimental value fluctuate; local field dipole theory model calculation results with the experimental value of the error range between -1.4% -0.6%, shows that the experimental value fluctuates up and down, and fluctuation range is larger; Classic dipole theory model calculation value and experimental value of error range between - 2.8% - 1.6%, in the experimental value fluctuates up and down, and fluctuation range is the largest. |
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