【文章內(nèi)容簡介】 γ為齒輪每轉(zhuǎn)一周，同一側(cè)齒面的嚙合次數(shù) ???齒輪的設(shè)計壽命 接觸壽命系數(shù) ???? 由圖 可知，取 ????1 = 1 ????2 = 接觸疲勞極限 由圖 ??????????1 = 710??????， ??????????2 = 580MPa 許用接觸應(yīng)力 [????] [????1] = ??????????1????1??????????= 710 = ?????? [????2] = ??????????2????2??????????= 580 = 驗(yàn)算 σH = ZEZHZε√2KT1bd2 ? u:1u = [σH2] 3. 確定傳動主要尺寸 實(shí)際分度圓直徑 d ??1 = ???? = 26 = 65mm ??2 = ???? = 104 = 260mm 中心距 a ?? = ??(??1:??2)2 = 齒寬 b ?? = ??????1 = 1 65 = 65mm 取 ??1 = 75mm,??2 = 65mm 4 .齒根彎曲疲勞強(qiáng)度驗(yàn)算 重合度系數(shù) ???? ??↑?? = +????= 齒間載荷分配系數(shù) ???? 由表 可知， ?????? = 1????= 齒向載荷分布系數(shù) ?????? ??? =65 = 由圖 查得， ?????? = 載荷系數(shù) K ?? = ???????????????????? = = 齒形系數(shù) ?????? 由圖 查得， ??????1 = ??????2 = 應(yīng)力修正系數(shù) ?????? 由圖 查得， ??????1 = ??????2 = 彎曲最小安全系數(shù) ?????????? 由圖 查得， ??????????1 = 600MPa ??????????2 = 450MPa 應(yīng)力循環(huán)次數(shù) ???? 由表 估計 3 106 NL 1010 ????1 = ???? = 60????1??? = 109 彎曲壽命系數(shù) ???? 由圖 可知， ????1 = ????2 = 尺寸系數(shù) ???? 由圖 可知 ???? = 許用彎曲應(yīng)力 [????] [????1] = ??????????1????1??????????????= 600 = [????2] = ??????????2????2??????????????= 450 = 驗(yàn)算 ????1 = 2????1????1????????1??????1???? = [σF1] σF2 = σF1 YFs2YSa2YFa1YSa1= [σF2] 符合要求。 低速級齒輪傳動的設(shè)計計算 材料選擇： 小齒輪選擇材料為 40Cr，需調(diào)質(zhì)處理，硬度為 260HB，大齒輪材料為45 鋼，硬度為 240HB，同樣需要調(diào)質(zhì)處理。 1. 齒面接觸強(qiáng)度計算 初步計算 轉(zhuǎn)矩 ??2 ??2 = 106 ????2= 106 = 377756N?mm 齒寬系數(shù) ???? 由表 可知 ???? = 初步計算許用接觸應(yīng)力 [????] [????1] ≈ ??????????1 = 639MPa [????2] ≈ ??????????2 = 522MPa Ad值 由表 可取 ???? = 85 初步計算 ??3 ??3 = ????√ ??2????[????]2? ??:1??3 = 取 ??3 = 105mm 初步齒寬 b ?? = ???? ???3 = 1 105 = 105mm， ??3 = 115mm ??4 = 105mm 2. 校核計算 圓周速度 ?? = ????3??3601000 = ?? 1059060 1000 = 精度等級 查表 選取精度等級為 9 級 齒數(shù) z 和模數(shù) m 初取 ??3 = 40， z4 = iz3 = 3 4 = 120 ?? = ??3??3= ，取 ?? = 3 ??3 = ??3?? = 1053 = 35， ??4 = 105 使用系數(shù) ???? 由表 選取 ????= 動載系數(shù) ???? 由圖 選取 ???? = 齒間載荷分配系數(shù) ?????? ???? = 2??2??3= 2 377760105 = ??????????3 = 115 = 100??/???? 先求：端面重合度 εα = ???? = √4 ?????3 = ?????? = 1????2= 齒向載荷分布系數(shù) ?????? ?????? = ?? +??[1+ ( ????3)2]( ????3)2+?? ? 10。3?? = 載荷系數(shù) K ?? = ???????????????????? = = 彈性系數(shù) ???? 由表 可得 ???? = √MPa 節(jié)點(diǎn)區(qū)域系數(shù) ???? 有圖 ZH = 接觸最小安全系數(shù) ?????????? ?????????? = 總工作時間 ??? ??? = 10 30016 = 48000h 應(yīng)力循環(huán)次數(shù) ???? 由表 估計 107 NL 109 ????1 = 60????1??? = 108 ????2 = ????1?? = 107 接觸壽命系數(shù) 由圖 選擇， ????1 = ????2 = 接觸疲勞極限 由圖 ??????????1 = 710??????， ??????????2 = 580MPa 許用接觸應(yīng)力 [????] [????1] = ??????????1????1??????????= 710 = 785MPa [????2] = ??????????2????2??????????= 580 = 663MPa 驗(yàn)算 σH = ZEZHZε√2KT2bd2 ? u+ 1u = [σH2] 3. 確定傳動主要尺寸 實(shí)際分度圓直徑 d ??3 = ????3 = 3 35 = 105mm ??4 = ????4 = 3 105 = 315mm 中心距 a ?? = ??(??3 + ??4)2 = 210mm 齒寬 b ?? = ??????3 = 1 105 = 105mm 取 ??3 = 115mm,??4 = 105mm 重合度系數(shù) ???? ??↑?? = +????= 齒間載荷分配系數(shù) ???? 由表 可知， ?????? = 1????= 齒向載荷分布系數(shù) ?????? ??? =1153 = 由圖 查得， ?????? = 載荷系數(shù) K ?? = ???????????????????? = = 齒形系數(shù) ?????? 由圖 查得， ??????3 = ??????4 = 應(yīng)力修正系數(shù) ?????? 由圖 查得， ??????3 = ??????4 = 彎曲最小安全系數(shù) ?????????? 由圖 查得， ??????????3 = 600MPa ??????????4 = 450MPa 彎曲最小安全系數(shù) ?????????? 由表 選擇， ?????????? = 彎曲壽命系數(shù) ???? 由圖 可知， ????3 = ????4 = 尺寸系數(shù) ???? 由圖 可知 ???? = 許用彎曲應(yīng)力 [????] [????3] = ??????????3????3??????????????= 600 = [????4] = ??????????4????4??????????????= 450 = 343MPa 驗(yàn)算 ????3 = 2????2????3????????3??????3???? = [σF3] σF4 = σF3 YFs4YSa4YFa3YSa3= [σF4] 直尺錐齒輪設(shè)計計算 直齒錐齒輪的加工方式多為刨齒，因此不宜采用硬齒面。小齒輪的材料選擇 40Cr，需要進(jìn)行調(diào)質(zhì)處理，硬度大小為 260HB,而大齒輪的加工材料可以選擇使用 42SiMn，同樣要進(jìn)行調(diào)制處理，硬度為 230HB。通過運(yùn)動循環(huán)簡圖和 整體機(jī)構(gòu)簡圖可以知道直尺錐齒輪的傳動比為 i=3，小齒輪轉(zhuǎn)速為 30r/