Stability Analysis Of A Full Floating Ring Bearing For Turbocharger

Turbocharger can effectively improve fuel combustion and engine power. It can also reduce the pollution to the environment. Now everybody is making his effort to save energy and reduce environment pollution, so the turbocharger has been applied more and more widely. The full floating ring bearing of turbocharger can shape dual oil film, which can improve the stability of the rotor operation and reduce the power consumption. In this paper, a model of turbocharger as research object. It will analyze the nonlinear dynamic characteristics and movement stability of system for turbocharger’s full floating ring bearing.Firstly, this dissertation summarized the common structural form and classification of turbocharger, working principle, functions and methods of pressure and common fault and the formation mechanism and the development ternd in the future is analyzed in. The Reynolds equation of full floating ring bearing of inner and outer oil films is derived. The nonlinear oil film force model of floating ring bearing is deduced. On the basis of Jeffcott rigid rotor, the dynamic equation of full floating ring bearing system is deduced.The dynamic equation of full floating ring bearing for turbocharger has been programmed, it is simulated with Matlab software when the parameters of the rotor eccentricity, inside and outside the oil clearance and lubricant viscosity ratio change. The dynamic characteristic and stability of the system of full floating ring bearing for turbocharger have been studied and the simulation results have been got and analyzed in the paper.The simulation results show that the dynamic characteristic of full floating ring bearing with different parameters are more complex. The rotor eccentricity can not only increase stability of system, but also play a role in instability. Appropriating to increase the amount of eccentricity can improve the stability speed range of the system. When designing a full floating ring bearing oil film clearance inside and outside, it is necessary to choose appropriate ratio and avoid excessive eccentric rotor at the same time. The change of the lubricating oli viscosity influence on the system, a reasonable lubricating oli viscosity can improve the stability of the system.