Research On New Self-propelled Tree Planting Earth Auger

To increase the forest coverage and improve the ecological environment, we must carry out afforestation energetically. Only the mechanization can further improve the productivity, lower the production cost, realize high-efficiency forestation. A earth auger is important equipment, and different kinds of earth augers are designed for differernt landform. In this paper, a new self-propelled earth auger is studied for the need of tree-planting in southward and modern design methods are applied in exploiting powerful, low-cost and high-efficiency earth augers.The new self-proprelled tree planting earth auger collects the running system and working part in one body at first time. To control running and working through making use of tension pulley clutch, and switch easily. Adapt to hilly conutry in Southern China whose grade is less than 25°. Selection of the design power of the gasoline engine 6.5HP, designed for digging in diameter between 150mm to 350mm. The new self-propelled earth auger who has small size, light weight, will accord with the demand of market.At the beginning of this paper, some kinds of domestic and international earth augers are introduced and some views on the development trend of earth augers are provided. Secondly, the general design principle of the new self-propelled earth auger is analyzed qualitatively and the choice types of each part is discussed, such as structural calculation or parameter determinaion of universal coupling, soft-shaft, bell wheel, bevel gear reducer, clutch of tension pulley, etc. A three-dimension model of the auger is established, using Pro/Mechanical to make sturctural stress analysis of auger's principal axis, giving the optimization design model of the principal axis according to optimization principle and then the optimization dimension in design range is obtained. And, soil cutting model of earth auger's blades is estabished, which shows reasonable selection range of cut-in angles and installation angles of blades. Then, the kinematice simulation analysis of the transmission mechanism and the running system is made, the change of drill tip's displacement, angular velocity, augular acceleration of universal coupling and running axle at each designed time are obtained, offering theoretical assistance for the design of parts and choice of power. Finally, the zoology benefits, society benefits and economy benefits of the digging machine are analyzed.