1、 20 2800 英文单词， 14500 英文字符，中文 4500 字 文献出处： Jia H, Ma C, Tong J. Study on universal blade rotor for rototilling and stubble-breaking machineJ. Soil & Tillage Research, 2007, 94(1):201-208. 毕业设计（论文） 外文翻译 学生姓名 班 级 学院名称 机电工程学院 专业名称 机 械 设计 制 造及 其自 动 化（ 机 械设计） 指导教师 201 年 月 日 21 Study on universal blade rot
2、or for rototilling and stubble-breaking machine H Jia ， C Ma ， J Tong Abstract We have developed a dual-functional machine which can perform both rototilling and stubble-breaking operations. This machine is characterized by a universal rotor and blade mounting disc mechanism, thus the two operations
3、 are performed, respectively, by simple change of the blades. In this paper we present the analysis of the main parameters of the rototilling and stubble-breaking working parts and their effect on the operation quality on the basis of different agro-technical requirements. We also present the design
4、ing considerations of the universal blade mounting system to ensure that both blades can be mounted in multi-spiral arrangements without interference. Field tests show that this dual-functional machine meets the agro-technical requirements in the northeast of China and possesses several advantages c
5、ompared with existing machines. Keywords: Rototilling blade; Stubble-breaking blade; Universal blade rotor; Multi-spiral arrangement; Rototilling and stubble-breaking machine 22 1. Introduction Plowing with the traditional moldboard plows was used in the early years worldwide. However, this operatio
6、n brought several problems that were gradually realized by farmers, agricultural engineers and researchers (Negi et al., 1981; Larney and Bullock, 1994; Olsen and Brresen, 1997; Lopez et al., 2000). These problems include severe wind and water erosion, increasingly worsening ecological environment, severe moisture loss in the soil and a significant decrease in soil fertility. To overcome such problems new cultivation machines, tillage and planting sys
