發布時間:2026-04-28 05:16:53 人氣:271825 來源:
1.泵自身構體引起的振動
離心泵是由軸、軸承及安裝在軸上的葉輪,驅動裝置(如電機、汽輪機、燃氣輪機驅動等)構成的。泵軸振動、轉子不平衡、驅動軸不同心、軸承缺陷、葉片及軸上其他部件鬆動等,都有可能引起振動。使用振動監測裝置可以測得單個振動頻率,用於分析這些振源類型。
裝在泵軸上的龍裏機械密封有不同的振動頻率,低時可在泵轉速以下,高時可達每秒數千次。如果振動頻率剛好與龍裏機械密封zhongdedanxingyuanjianguyoupinlvxiangtong,jiukezaochengmocafumosunjiakuaihuopilaosunshang。dangran,zhezhongsunshanghaiyouqitayinsu。suoyizaishejihuoxuanxingshi,bixubaozhengkeyucedegongzhenpinlvbuyaoyujilipinlvzhonghe,yingcaiqukekaojianzhencuoshi,shejidelinjiezhuansubunengyugongzuozhuansuxiangjutaijin;在操作溫度下,將安裝誤差減至最小,因為這些誤差會導致密封彈性裝置的位移;轉子要充分平衡;垂直安裝軸上的軸承,其承受的載荷應使滾動件打滑的可能性減至最小。

需要說明的是:
(1)龍裏機械密封的彈性元件(包括單彈簧和多彈簧),彈簧本身可承受大部分振動載荷,輔助密封也有一定減振效果,如楔形環、O形圈、膨脹石墨等;
(2)對於支承在彈簧上的質量較小的密封,如石墨密封環的結構,其固有頻率相對較大;
(3)支zhi承cheng在zai低di彈dan性xing彈dan簧huang上shang的de質zhi量liang較jiao大da的de密mi封feng,其qi固gu有you頻pin率lv相xiang對dui較jiao小xiao,且qie腔qiang體ti內nei壓ya力li較jiao低di情qing況kuang下xia出chu現xian共gong振zhen可ke能neng性xing較jiao小xiao,金jin屬shu波bo紋wen管guan型xing密mi封feng根gen據ju不bu同tong的de強qiang度du設she計ji,其qi彈dan性xing有you高gao有you低di;
(4)由於沒有滑動的輔助密封,所以依靠密封端麵上的液膜或液體減振,當然也可以設計帶滑動的輔助密封,提高它的穩定性和剛性;
(5)大多數龍裏機械密封的固有頻率都遠高於正常的操作轉速,對於金屬波紋管型龍裏機械密封,要特別注意避免軸向共振,異常振動會加劇波紋管疲勞斷裂。如泵軸上軸承的軸向遊隙調整不當就容易出現這現象。
lingwaigenjumifenghuancailiaodebutong,tebieshidangcaiyongtanhuawuleigaomiducailiaoshi,gengyingzhuyigongzhenwenti。yinci,dangzhichengzaidanxingyuanjiandemifenghuanxuyaocaiyongyingzhicailiaoshi,tiaojianyunxuqingkuangxiayibandouxuanyongmiduxiangduijiaodidetanhuagui、陶瓷等材料。
2.在正常及擾動條件下產生的振動
泵運行時,其轉子及龍裏機械密封會hui受shou到dao液ye力li振zhen動dong影ying響xiang,當dang流liu量liang發fa生sheng變bian化hua時shi,葉ye輪lun入ru口kou處chu液ye體ti會hui產chan生sheng波bo動dong,若ruo不bu是shi在zai最zui佳jia效xiao率lv下xia運yun行xing,葉ye輪lun入ru口kou及ji擴kuo壓ya管guan處chu的de流liu體ti壓ya頭tou會hui增zeng大da。低di於yu或huo高gao於yu最zui佳jia效xiao率lv點dian的de流liu量liang時shi,或huo輸shu送song介jie質zhi無wu法fa達da到dao泵beng的de氣qi蝕shi餘yu量liang時shi,都dou可ke能neng產chan生sheng氣qi蝕shi現xian象xiang,則ze密mi封feng激ji振zhen就jiu更geng明ming顯xian。另ling外wai,入ru口kou處chu介jie質zhi的de流liu動dong還hai會hui受shou到dao泵beng內nei介jie質zhi自zi循xun環huan的de幹gan擾rao。
轉zhuan子zi係xi統tong的de振zhen動dong及ji作zuo用yong在zai密mi封feng上shang壓ya力li狀zhuang況kuang的de變bian化hua,所suo引yin起qi的de振zhen動dong的de振zhen幅fu和he頻pin率lv是shi隨sui機ji的de。在zai設she計ji係xi統tong和he選xuan擇ze泵beng時shi,應ying使shi其qi在zai最zui佳jia效xiao率lv狀zhuang態tai下xia運yun行xing,保bao證zheng泵beng在zai負fu壓ya情qing況kuang下xia工gong作zuo穩wen定ding,即ji保bao證zheng泵beng有you足zu夠gou氣qi蝕shi餘yu量liang,防fang止zhi介jie質zhi在zai龍裏機械密封的表麵氣蝕產生激振。
3.溫度及壓力變化使泵變形而產生的振動
泵運行過程中,溫度發生變化時,泵的各部件會產生熱變形,這時泵相對於驅動裝置會發生偏移,引起龍裏機械密封zhendong。ciwai,wenduduiketihezhuanzideyingxiangchengdubuyiyang,yibanqingkuangxia,zhuanziyaobiketibianhuaxunsu。dangyunxingwendubodongshi,mifengchuleyaochengshoubujiancuoweichanshengdezhendongwai,haiyaochengshoudipinlvdazhenfudezhendong。youyu龍裏機械密封的一側固定在殼體上,而另一端固定在轉軸上,所以必須有吸收這兩種不同振動的能力。
壓力也能使泵體變形,從而多龍裏機械密封產生幹擾。當密封腔內壓力發生變化時,作用在密封端麵上的載荷也會隨之發生變化,從而產生突變載荷引起振動。
4.製造安裝原因產生的振動
mifengduanmiancucaoduguoda,bunengbaozhenghenhaodetiehexing,mifengdewendingxingjiuhuishoudaoyingxiang,yingxiangchengdubujinqujueyumifengdejutijiegou,erqiequjueyumifengyunxingcanshu。mifengmeixuanzhuanyizhouqibuchanghuandouyaozuoxiangyingdeyunxing,congerbaozhengmifengduanmiandetiehexing。duiyuhuadongfuzhumifengjian,ruOxingquanhuoxiexinghuan,mifengmianshangdezaiheyanyuanzhoubianhua,yingjinliangfangzhibushouzaihedeyicefashengxielou,shouzaihedeyicechuxianguodumosundexianxiang。xielouhuishiliutidezalishendaoduanmianyemozhong,congerjiasumifengduanmianmosun。
mifengjianzaijiagongguochengzhong,yibanbunengyongjixiefangfajiayipingheng。zaishejizhongyaojinliangjianshaobupinghengyinsu,rudandanhuangjiuhuizaochengbupingheng,tebieshizaizhizaocucaodedonghuanhuoxiangmifengjianchuandidedonglijuyou“尾隨脈衝”情況時,更應注意不平衡問題。
zaicaiyongneizhuangshijixiemifengshi,zuoyongzaimifengshangdechongjilichangchangshiyoubengsongjiezhidezixunhuanzaochengde。weiquebaomifengxingneng,zixunhuanyetiyingcongliangmifengduandewaicetongguo。ruoliuliangguoda,zezuoyongzaimifenghuanshangdechongjilikenenghuishimifengduancuowei,qihouguoziranshizhendong。
為減輕振動的影響,可以使自循環流體,由切向入口;ruyoukeneng,xunhuanliuliangkeyitongguomifengqiangneichentaodepeihejianxijiayikongzhi,huozhejiangmifengqiangneidexiruguanhepaichuguanfanjie,shiliuxianggaibianerxingchengnixunhuan。houyizhongfangfachangzailishibengzhongcaiyong,yinweitatongshijiejuelemifengqiangshangbudepaiqiwenti;但是,這常被人們所忽視,甚至在臥式泵的設計中,密封腔內由於逆循環產生的壓差而會顯著改善密封效果。