Finite Element Analysis And Research On Heavy-Duty Truck Gearbox Housing

As an important part in the automobile, the carrying capacity and working reliability of the gearbox has a great influence in terms of automobile's smoothness, handing and economical efficiency etc. Meanwhile, the gearbox's vibration characteristics are in connection with the automobile's comfortableness. The strength and stiffness of the gearbox housing which is as a gearbox's carrier will affect the gearbox's performance and life.In this thesis, the heavy-duty truck's gearbox housing is studied and conducted relevant research for the analysis object. On the basic of making some necessary simplification for the housing, the simplified three-dimensional model is built with three-dimensional modeling software. The housing's meshes is divided with finite element pre-processing software. For the connection between housings, MPC contact algorithm is used in the thesis to couple the discontinuous nodes on the housing's contact surfaces. Meanwhile, using beam elements to simulate auxiliary support on the housing.On the basic of stress analysis of housing's bearing seats, the loads on the finite element model of the housing are applied with cosine function load command. The strength and stiffness of the housing is calculated and the stress and displacement contours are obtained. The contours show that the stress in the middle housing's bearing seats is larger, but it is not exceed the allowable stress of the housing's material. The housing's deformation is less than 0.2mm. The strength and stiffness is meeting the design requirements and the housing is safe and reliable.Using finite element software to analysis the housing's mode, the first 20 modal frequencies and mode shapes of the housing is calculated to determine the dynamic characteristics of the housing. As can be seen from mode shapes, the middle housing is the sensitive vibration part of the housing. By comparing each modal frequency of the housing and the gears'meshing frequency, the result shows that the third-order natural frequency of housing is close to the meshing frequency of the first gears when the engine's speed is 1500rpm, which is the maximum torque output condition. So the gearbox is more likely to resonance. Because the engine can output the maximum torque at 1100-1500rpm, the resonance can be voided by controlling the engine speed reasonably at this speed range.The dates and the conclusions that obtained by researching the housing with FEA are provide a reference for optimization of the housing.