文档介绍：螺旋千斤顶设计说明书学院:XXXX班级:XXXX姓名:XXXX学号:XXXX目录一、确定螺杆、螺母材料··········································3二、螺纹相关参数的确定··········································3三、螺杆的设计··················································4四、螺母的设计··················································6五、螺纹牙强度校核··············································7六、托杯的设计··················································8七、手柄的设计··················································9八、底座的设计··················································10九、详细装配图··················································12十、参考文献····················································12详细设计如下:、螺母材料由于起重器的载荷,低速运行,按表5-11【1】选取螺杆材料为45钢,并采用正火处理,由表8-17【2】得:螺杆材料为45钢螺母采用::其抗拉强度为屈服强度(GB/T699-1999)螺母采用,采用砂型铸造,由表8-26【2】得:其抗拉强度为屈服强度(GB/T1176-1987)根据对螺纹类型和相关传动特点的比较,选择梯形螺纹梯形螺纹牙根强度高,工艺性好,对中性好计算中取,查表5-12【1】,取,f=:根据耐磨性条件,初步估算螺杆中径式中:F——作用与螺杆的轴向力,单位NP——螺纹螺距,单位mmh——螺纹工作高度,单位mmA——螺纹的承受面积,单位H——螺纹高度,单位mmu——螺纹工作圈数。又有:代入得到:,得查表8-45【2】,根据梯形螺纹的标准GB/-2005,取螺纹公称直径,螺距为查表8-46【2】,根据梯形螺纹的标准GB/-2005,得梯形螺纹其它尺寸:螺杆小径:,螺杆螺母中径:选用梯形螺纹螺杆中径螺纹参数:::,螺母小径:螺母高度:螺纹牙根部宽度:已知螺距,根据公式,得:<10,满足要求。螺纹升角:当量摩擦角:其中由表得到因此<,符合自锁条件。螺杆在设计时要进行强度校核和稳定性校核(耐磨性和自锁性之前已有校核)。螺杆工作时承受轴向压力F和扭矩T的作用,其强度条件为:<式中:A——螺杆螺纹危险截面面积,;——抗扭截面系数,;T——螺杆所受扭矩。其中,螺杆所受转矩为:<10合理<合理,能自锁<-13【1】,取螺杆许用应力得<所以,螺杆符合强度条件螺杆的柔度:其中,u——螺杆长度系数,由表得u=2。——螺杆工作长度,:其中为最大举重升距;为螺杆头部长度,;为退刀槽宽度,参照普通螺纹退刀槽的参数可得,;H为螺母高度;所以可得,。——惯性半径,。柔度:,螺杆危险截面惯性矩:螺杆临界载荷:计算安全系数:所以满足稳定性条件,,可确定螺杆参数如下:(退刀槽,GB/T3-1997)(头部直径)已知螺纹参数:根据文献查得千斤顶经验计算公式如下:螺母下端悬置部分既受到拉力的作用,又受到螺纹牙上摩擦扭矩对螺母的作用。本文将拉力增大20%~30%来考虑扭矩对螺母的作用,这样个方法是一个经验性的方法,是可取的。由表得到:<,满足强度条件<,、剪切强度校核以及弯曲强度校核。=,<,满足挤压强度条件由表得,<,满足剪切强度条件<,满足弯曲强度条件螺纹牙多发生剪切和挤压破坏,一般螺母的材料强度低于螺杆,故只需校核螺母螺纹牙的强度。<,满足剪切强度条件其中:F——所受载荷;