Based on the theories of hydraulics and nonlinear control system, the model of hydroviscous drive (HVD) was established, the influences of small ripple of control oil pressure on the output speed of HVD and the stability of oil film between friction disks were analyzed. The conclusion presents that when the frequency of the control oil's pressure ripple is higher than 60?Hz and the peak is less than 0 05?MPa, HVD can work stably. The result is useful for studying the application of frequency conversion technology in regulation of control oil pressure.
Gives a dynamic mathematical model of a typical type of multiple discs hydroviscous drive device which has been proved to be correct through tests.Utilizing the method of root-locus analysis the dynamic performance of this device is studied according to the model.Theoretical analysis and test re- suits show that the dynamic performance of the object of study can be greatly improved by speed negative feedback.
To improve the electrorheological effect of electrorheological fluid (ERF), a new type of the electrosensitive particle material, polynaphthalene quinone was prepared, whose molecules contain blended atoms of nitrogen, oxygen, sulphur and big π bond conjugate system. In both DC and AC electric fields, the ERF material showed a distinct ER effect. Especially, in the alternating electric field, the shear stress of this material versus AC voltage has a better quadratic relation than that of the other materials. The experimental data showed that organic semiconductor polymers with big π bond conjugate system are a new type of electrosensitive particle materials which are worth well developing.
Aim To carry out an experiment of the application of ER fluids in the clutch by reforming a fan clutch used in a truck. Methods At three different input rotating speeds,when the strength of applied electric field was changed, the output rotating speeds were recorded and analyzed. Results By comparing the results got under different experimental procedures with those measured with an electro-rheometer, it can be seen that the shearing rate has tremendous influence on the speed modulating of a fan clutch. This is because the disperse phase can't form chains (clusters)easily at high shear rate.Conclusion The result tested on the present ER fluid demonstrates that this fluid will show the properties of Newton one,i.e. its apparent viscosity is constant. as the shear rate increases.
