螺旋千斤頂設計計算說明書院 系 工 程 技 術 學 院 專業(yè)年級 設 計 者 指導教師 成 績 1螺旋千斤頂設計任務書學生姓名 專業(yè)年級 設計題目： 設計螺旋千斤頂設計條件：1、最大起重量 F = 65 kN；2、最大升距 H =240 mm。設計工作量：1、 繪制出總裝配圖一張，標注有關尺寸，填寫標題欄及零件明細表；2、 編寫設計計算說明書一份。指導教師簽名： 20 年 月 日2目錄1 螺桿的設計與計算··················································································································31.1 螺桿螺紋類型選擇····································································································31.2 選取螺桿材料·············································································································31.3 確定螺桿直徑·············································································································31.4 自鎖驗算······················································································································31.5 結(jié)構(gòu)································································································································41.6 螺桿強度計算·············································································································41.7 穩(wěn)定性計算··················································································································51.7.1 計算柔度·········································································································61.7.2 計算穩(wěn)定性····································································································62 螺母設計與計算···················································································································3···62.1 選取螺母材料·············································································································62.2 確定螺母高度 H?及螺紋工作圈數(shù)u······································································62.2.1 求螺母高度H?································································································72.2.2 螺紋工作圈數(shù)u·····························································································72.2.3 螺母實際高度H?····························································································72.3 校核螺紋牙強度·········································································································72.4 結(jié)構(gòu)要求······················································································································83 托杯的設計與計算··················································································································84 手柄設計與計算······················································································································94.1 手柄材料····················································································································104.2 手柄長度Lp···············································································································1044.3 手柄直徑dp···············································································································114.4 結(jié)構(gòu)·····························································································································115 底座設計··································································································································12參考資料·····································································································································13螺旋千斤頂設計計算及說明 結(jié)果51 螺桿的設計與計算1.1 螺桿螺紋類型的選擇螺紋有矩形、梯形與鋸齒形，常用的是梯形螺紋。梯形螺紋牙型為等腰梯形，牙形角 α=30o，梯形螺紋的內(nèi)外螺紋以錐面貼緊不易松動。故選梯形螺紋，它的基本牙形按GB/T5796.1—2005 的規(guī)定。1.2 選取螺桿材料螺桿材料常用 Q235、Q275、40、45、55 等。1.3 確定螺桿直徑按耐磨性條件確定螺桿中徑 d2。求出 d2 后，按標準選取相應公稱直徑 d、螺距 t 及其它尺寸。有 d2≥ ??phF??根據(jù)國家規(guī)定 =1.2~3.5，取 =1.2（梯形螺紋） ；h=0.5t；查?教材表 5-12， [p]取 20Mpa。故，d 2≥ = 0.8 =41.5mm??hFt??][p?查機械設計課程設計手冊，d 取48mm，t=8mm，d 1=39mm，d 2=44mm1.4 自鎖驗算自鎖條件是 ?≤?v，式中： ?為螺紋中徑處升角； ?v 為當量摩擦角（當量摩擦角 ?v=arctan?v，但為保證自鎖，螺紋中徑處升角至少要比當量摩擦角小 1°。查教材表 5-12，f 取 0.09? = arctan(t /? d2)=arctan[ 8/(3.14 )] =2.88°4??v=arctan（f/cosβ）=arctan[ 0.09/cos(30°/2)]=5.35°選梯形螺紋選 40 鋼d=48mmt=8mmd1=39mmd2=44mm?=2.88°?v=5.35°?
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