2020/3/5
而(T
運(yun)(yun)(yun)動(dong)(dong)部件(jian)制(zhi)(zhi)動(dong)(dong)時(shi)產生的(de) 液(ye)(ye)(ye)(ye)壓(ya)(ya)沖擊Δp=ΣmΔv/FΔt(公(gong)斤力(li)(li)/厘米2)式中(zhong):m—被制(zhi)(zhi)動(dong)(dong)運(yun)(yun)(yun)動(dong)(dong)部件(jian)的(de) 質量(公(gong)斤力(li)(li)?秒2/厘米)F—液(ye)(ye)(ye)(ye)壓(ya)(ya)缸有效工作面積(厘米2)由上式可知,為(wei)減(jian)小(xiao)(xiao)運(yun)(yun)(yun)動(dong)(dong)部件(jian)制(zhi)(zhi)動(dong)(dong)時(shi)產生的(de) 液(ye)(ye)(ye)(ye)壓(ya)(ya)沖擊,應(ying)延長制(zhi)(zhi)動(dong)(dong)時(shi)所需的(de) 時(shi)間(jian),或縮小(xiao)(xiao)運(yun)(yun)(yun)動(dong)(dong)部件(jian)速度的(de) 減(jian)小(xiao)(xiao)值(zhi)。如在(zai)液(ye)(ye)(ye)(ye)壓(ya)(ya)缸行程終點(dian)采用減(jian)速、節流等緩沖裝置等。二、空穴現(xian)象液(ye)(ye)(ye)(ye)壓(ya)(ya)泵(beng)吸油入(ru)口(kou)壓(ya)(ya)力(li)(li)可按(an)下式計算p泵(beng)=pa-(hλγ+v2γ/2g+?v2γ/2g +p慣(guan))式中(zhong):p泵(beng)—液(ye)(ye)(ye)(ye)壓(ya)(ya)泵(beng)吸油入(ru)口(kou)壓(ya)(ya)力(li)(li)吸油損(sun)耗pa—大(da)氣壓(ya)(ya)力(li)(li)p慣(guan)—由于(yu)液(ye)(ye)(ye)(ye)體(ti)在(zai)吸入(ru)管和泵(beng)室中(zhong)加速運(yun)(yun)(yun)動(dong)(dong)所產生的(de) 壓(ya)(ya)力(li)(li)。
一(yi)般(ban)(ban)液(ye)(ye)壓(ya)系統油(you)(you)溫(wen)(wen)(wen)(wen)不超(chao)過(guo)(guo)70℃,一(yi)般(ban)(ban)液(ye)(ye)壓(ya)系統油(you)(you)溫(wen)(wen)(wen)(wen)不超(chao)過(guo)(guo)70℃,一(yi)般(ban)(ban)液(ye)(ye)壓(ya)系統油(you)(you)溫(wen)(wen)(wen)(wen)不超(chao)過(guo)(guo)70℃,熱計(ji)算油(you)(you)溫(wen)(wen)(wen)(wen)高(gao)60℃。高(gao)壓(ya)系統油(you)(you)溫(wen)(wen)(wen)(wen)不超(chao)過(guo)(guo)50℃,機床(chuang)系統油(you)(you)溫(wen)(wen)(wen)(wen)不超(chao)過(guo)(guo)室溫(wen)(wen)(wen)(wen)25℃,精(jing)密機床(chuang)液(ye)(ye)壓(ya)系統油(you)(you)溫(wen)(wen)(wen)(wen)不應(ying)超(chao)過(guo)(guo)室溫(wen)(wen)(wen)(wen)10℃~15℃。各油(you)(you)溫(wen)(wen)(wen)(wen)范(fan)圍的(de)(de)(de)性質可參見下表(biao)。溫(wen)(wen)(wen)(wen)度(du)范(fan)圍(℃)表(biao)明,在80或100的(de)(de)(de)危(wei)險(xian)溫(wen)(wen)(wen)(wen)度(du)區(qu)內不允許(xu)使用65°80臨界溫(wen)(wen)(wen)(wen)度(du)區(qu)域(yu)內的(de)(de)(de)油(you)(you)的(de)(de)(de)壽命,必(bi)須安(an)裝冷卻(que)器(qi)。對于(yu)每8℃的(de)(de)(de)溫(wen)(wen)(wen)(wen)升,油(you)(you)的(de)(de)(de)壽命縮短一(yi)半。注意油(you)(you)溫(wen)(wen)(wen)(wen)在整個溫(wen)(wen)(wen)(wen)度(du)區(qu)域(yu)47/55中(zhong)的(de)(de)(de)啟動危(wei)險(xian)、理(li)想溫(wen)(wen)(wen)(wen)度(du)區(qu)域(yu)20/30中(zhong)的(de)(de)(de)油(you)(you)溫(wen)(wen)(wen)(wen)以(yi)及(ji)低溫(wen)(wen)(wen)(wen)區(qu)域(yu)中(zhong)的(de)(de)(de)啟動危(wei)險(xian)。