Abstract: For the aging and wear of the rubber nodal points of linear motor due to the drastic vibration of unsprung structure of certain type of linear motor at home, the method of taking the whole linear motor suspension as a vibration isolation system is introduced. A displacement functional matrix with three degrees of freedom can be established through transfer function, and the analysis of characteristics of vibration isolation of the linear motor system can be attained. The optimization analysis of the rubber joint stiffness of linear motor suspension system can be performed through choosing different optional factors. Compared with the calculation results, the obvious decrease of the value of transfer function and the apparently functional improvement of vertical vibration isolation can be found when the optimizing factor is selected as 0.1 to optimize the support pad of the suspension beam and the vertical stiffness of the hanger node. Through further comparison and dynamics analysis of metro vehicles before and after optimization, the result shows that the amplitude and frequency of vibration acceleration of after-optimized model motor decrease obviously and can quickly converge. The stiffness optimization of suspension system of linear motor of metro vehicles is of great significance for its vibration isolation function.

Key words: linear motor, metro vehicle, stiffness optimization, transfer function, vibration isolation