Abstract:

A gear decelerator is a complex elastic system with multiple transmission. Its dynamic characteristic appears as nonlinear varying phenomena because of the nonlinear influence of gear meshing stiffness and transmission error as well as the nonlinear action of bearing supporting stiffness. The system stiffness was analyzed always by a fixed constant method; in fact, it did not accord with the practice of engineering. In this paper, the fluctuation of gear meshing stiffness, the influence of transmission error, and the action of bearing supporting stiffness are considered all together. And the theoretic modeling and dynamic response analysis are done for the transmission system with bi grade taper cylinder gears. The nonlinear terms of the transmission error are dealt with the method of Fourier series expansion. Furthermore, the theoretic analysis is compared with the experimental results. It is shown that the meshing stiffness of gear transmission varies evidently between the single toothed meshing zone and double toothed meshing zone, but it varies slowly in the same meshing zone. The dynamic characteristics of the decelerator, i.e. the natural frequency, the mode shape and so on, vary with meshing period. It appears to be a variable natural characteristic. Therefore, the multiple gear transmission system shall be analyzed according to the mean meshing stiffness of the single toothed meshing zone and double toothed meshing zone respectively, and in doing so, it may meet the requirements of engineering.

Key words: g ear decelera tor, meshing stiffness, tr ansmission er ro r, bear ing stiffness, dynamic naturalcharacter istic, dy namic analy sis