Dynamic Analysis of Gear Box

In the present study, two different methods for simulate the dynamic behavior of gears are described and compared. The nonlinear torsion vibrations of geared systems are studied at resonance frequency with the contact loss of the meshing teeth. In the proposed model a time-varying mesh stiffness of tooth pairs and a viscous damping proportional to the meshing stiffness are considered. Gear errors of each meshing tooth pair are also included. Dynamic motion of the spur gear pair over wide range of excitation frequency using the finite element method was simulated. Results of bending stress distribution during overall operation speeds were obtained by FEA. It may serve as a tool for aiding the gear fault diagnosis. Gears are used to increase or decrease input speed. These gears are enclosed in a rigid closed housing called casing. The function of gearbox casing is to protect and provide a platform for gear transmission. The casing supports the shaft, hold the lubricant inside and protect the gears from dust and moisture from outside environment. Also it provides necessary cooling surface to dissipate the heat generated during the operation. The strength of the gearbox casing is an important parameter to be taken into account while designing the gearbox. The vibration analysis of gearbox casing is done using accelerometer along with a device called Fast Fourier Transform (FFT) analyzer. The main reason for heavy vibration is the resonance caused by the lower order frequency of transmission gearbox body.