Parametrical Design For Transmission Of Hillside Tractor

Hillside tractor is a significant machine for hillside farming. And the transmission is one of the key components, whose stability holds an important influence on the hillside tractors’ operating reliability. The traditional design methods have the weakness of long design cycle, low design accuracy and bad reliability, which is hard to meet requirements of the market. In order to solve these problems, this article studied and designed the drive system of the hillside tractors’ transmission, developed the parametric design system of the drive system, built the 3D parametric model, and optimized its sizes. The main contents include:(1)The existed transmissions of hillside tractors’ structure and drive characteristics were analyzed. Based on the working requirements and conditions, the operation condition parameters were presented. According to traditional design method, the number of tooth, modules, center distances in each tap position were computed, and the drive ratios of each tap position were reasonably distributed.(2)The skeleton pattern of transmissions’ drive system on hillside tractors were built through Pro/E. Based on the skeleton pattern, the 3D model of transmissions’ drive system on hillside tractors were built, which deceased the working force of modeling, and increased the design efficiency.(3)Based on the Visual Basic language, the CAD design system of hillside tractors’ transmissions were projected, which was able to deal with the line graphs and tables into programs, compute the drive ratio and the tooth numbers in each tap position, and check the strength of gears, axials and splines. Besides, the gears were checked in bending strength through Solidworks software.(4)The Automation Gateway software was utilized to realize the second development of transmissions’ Pro/E model, and the parametrical design was realized through parametrical driving technology.(5)The gears’ minimal volume, the transmissions’ minimal axial length and the minimal lateral area were set as the objective functions, and the strength conditions, interference conditions were set as constraint conditions. The GA algorithm in Matlab was called to optimize the total volume and the total mass. The result is to reduce the total mass by 4.3%, and to reduce the total volume by 41.7%, which had an obvious effect.This article parametrically designed the drive system of hillside tractors’ transmissions, realized its size optimization, and the optimized 3D model was generated, which was able to shorten the developing time and decease the developing cost. Besides, it built the transmission 3D model as a whole and proposed the new idea of parametric design, which had a significant meaning for the parametrical study and secondary development of transmissions of hillside tractors.