The Mechanism Research On Wheelset Stability

Because of the high-speed railway has the advantages of mass transportation ca-pacity, lower energy consumption, safety performance is high, slight environ mental pollution, the no affected by climate. So at home and abroad, the high-speed railway gets fast development. Scientists have done a lot of research on how to improve the critical speed.They also want to know which factors affect the critical speed.They study the linear system or nonlinear system.For linear systems.For linear systems,eigenvalues of the linear differential equations, damping coefficient method and Routh-Hurwitz criteria that are always used to determine whether the vehicle is in motion instability.These methods can determine whether the vehicle instability, but can not explained the role of gyroscopic forces in the stability.Previous research suggests that gyroscopic forces play a small role at low speed.But now,the speed has already more than300km/h.In this paper, I do a series of studies on stability by used a complete restraint system equation.The main job incoleves:(1)I studied the the progress made in related fields, by reading a lot of literature abort High-speed rotating bearing,High-speed rotor,Launch vehicles on stability.Then,I sort out the stability theory can be applied.(2)Using the research on relative field,the article gives a detailed introduction to the complete restraint system equation.Then,I derived a stability criterion.In addition, I also defined two kinetic stability coefficient and influence coefficient of gyroscopic forces.(3)I derivate the wheelset equations, and converte it into complete restraint system equation.Then we get inertia matrix M,damping matrix D,gyroscopic matrix Qstiffness matrix K and cyclic matrix E.Where D、K are symmetric matrix, G, E are skew-symmetric matrix.(4)Using the new discriminant,we derive the analytic expression of wheelset on the critical speed. (5)Writing Matlab program and put the data into critical velocity analytic formula,we get the critical speed.We get the the relationship between critical velocity and some parameters,such as stiffness,creep coefficient,equivalent conicity,damping.(6)Taking advantage of the new definition of gyroscopic forces influence coefficients,we get the gyroscopic forces affecting rate formula.In addition, we also get the relationship between gyroscopic forces affecting rate and speed...