毕业答辩论文无动力手推式割草机设计无动力手推式割草机设计目 录摘要 ....................................................................4Abstract ................................................................5第一章 绪论 ............................................................6........................................................................6 无动力手推式割草机国内外的进展现状.....................................6 割草机的概述...........................................................8.......................................................................8 手推式割草机的结构特点...............................................10 如何安全操作草坪割草机...............................................11第二章 割草机总体方案的设计..........................................12第三章 割草机零部件的设计............................................15 割草机行走轮的设计....................................................15......................................................................17 凸轮的设计............................................................17 凸轮材料的选择.......................................................17.......................................................................18 切割器材料的选择.....................................................20.......................................................................23......................................................................23 轴的设计.............................................................23 轴的材料选择.........................................................23.......................................................................24......................................................................24 球轴承的特点.........................................................24 轴承的转速...........................................................24 键的选择..............................................................25 平行四杆机构的设计...............
