Finite element analysis and experimental investigations of the back case of a transmission with a central brake

Because of limitations in the vehicle layout, a central brake system was installed directly on the transmission's back case of a certain type of medium-size truck. Under the condition of emergency braking, the back case easily fails because of the large braking torque. In this paper, a method of structure improvement, finite element analysis and experimental investigations of the transmission's back case was proposed. Two improved designs of the back case are discussed. The finite element analysis results indicated that the improved back case was capable of bearing the maximum braking torque, which was also verified by vehicle road tests and torque tests. The modal analysis results implied that the lowest free modal frequency of the improved back case was increased and far away from the engine excitation frequency. In addition, the first-order constrained modal frequency was also greater than the gear meshing frequency. The overall results implied that the improved design of the transmission's back case was applicable under normal conditions, and the proposed method was sufficiently accurate for wide use.