Study On Gear Weight Reduction Design For Drive System Of Twin Screw Pupling Extruder

Twin screw pulping extruder is a new kind of energy-saving pulping machine, and it has a good characteristic and broad application. Drive system is one of the most important parts of twin screw pulping extruder, but at the moment the design methods of drive system mainly rely on analogy and empirical law, the volume of drive system is large and the energy consumption of motor is relatively high, resulting in more serious material consumption and energy waste. Therefore, it is necessary to study the gear weight reduction design for the drive system of twin screw pulping extruder.The paper briefly describes the development of twin screw pulping extruders and its drive system, expounds the method of optimization design for the gear of drive system, then elaborates on the application of light weight materials and structural optimization in weight reduction design of mechanical equipment. By analyzing various kinds of weight reduction method, the weight reduction design programme for drive system is proposed according to practical design requirements of drive system of twin screw pulping extruder.By analyzing the methods of transmission ratio design for the existing multi-stage gearbox, the multi-optimization model which aims to minimize the sum of the volume of gear drive and the equivalent moment of inertia of input shaft synchronously is established, and design variables and constraint conditions are determined. MATLAB optimization toolbox is adopted to solve the multi-optimization model, the reasonable drive ratio and design parameters of gears are obtained. As a result the weight reduction design for drive system is achieved by adopting multi-optimization design.On the basis of gear parameters multi-optimization design, by handling the load properly, defining the minimum compliance of gear as objective function and volume function as constraint function, the structrual topology optimization is performed to optimize the former conformation of relatively large gear through ANSYS software, and the best material distribution on the former is obtained. As compared with the gear structure recommended in the mechanical design handbook, the weight and moment of inertia of gear are further reduced after topology optimization, so the weight reduction design for relatively large gear of drive system is achieved.Considering the requirement of processing technic, the structural design is adopted to determine the sturcture and dimensions, furthermore, statics and dynamic behaviour finite element analysis of the weight reduction gear is carried out bu using ANSYS. The analysis results indicate that the static strength and dynamic behaviour of the weight reduction gear can satify the requirements, therefore the reasonability of structural topology optimization for the former of gear is verified.This paper presents a thorough study in the theory and method of weight reduction design for the drive system of twin screw pulping extruder, and proposes two-step weight reduction approach of parameter multi-objective optimization and structural optimization. The work is of much importance to the weight reduction design for the drive system of twin screw pulping extruder and other mechanical drive system.