Structure Optimization Of The Base And Torsional Vibration Analysis Of The Shaft About The Explosion-proof Electric Motor

Base of the explosion-proof motor is a very important component of the motor and it bears a large load under various conditions, if the local stress is too high the load will lead to structural damage, even cause abnormal swing and a strong vibration unit at the spindle, which causes the motor life to cut down, meanwhile causes significant loss. The traditional design method uses simplified calculation of mechanical design combined with the experience of the method to determine the strength of the base. This design method has be proven a reliability, but this approach is also problematic such as the design cycle is long, less reasonable structure, the design is too conservative, too large margin. This often causes the base too heavy, and because of the extensive use of steel, its cost is high, which leads to the product are lack of competitiveness. Therefore it is necessary to lighten the weight of the base in the case of guarantee its performance. Finite element method and optimization methods are the main elements of modern design method. Using the finite element method to analysis the base under various conditions, then to optimize the base, and the result will make the structure and properties of the base more perfect.Based on the results of the finite analysis, we can accomplish the optimization design of the base. The result will reduce the weight of the base from 3 814 kilogram to 3 125 kilogram, which is eighteen percent lighter than the original weight. The result of optimization achieves a satisfactory result.The torsional vibration model based on the shaft of Synchronous Machine is established, contrarily to the TAW 2800 synchronous motor of the Nan Yang Explosion Protection Group CO., Ltd. The intrinsic characteristic is caculated by finite element and transfer matrix method. The caculating model of torsional vibration response is established and response calculation for the connect point with compressor is done. The result shows that the maxium stress is at the shaft connected with compressor and is a key place that affects the life of the shaft.