【正文】
故 X軸 mmmES FK ??? )(10001000 5m a x ???? ??????? 滿足要求 2)傳動(dòng)效率計(jì)算 絲杠螺母副的傳動(dòng)效率: )( ?? ?? ?? tg tg 滾動(dòng)摩擦系數(shù) 181。= 則摩擦角 ? == X軸與 Y軸的傳動(dòng)效率都為)( ,?? ??tg tg? =94%90% 符合要求。 其他裝置的選型 軸承的選擇 X軸支承形式采用兩端固定,選 60176。角接觸球軸承 絲杠 d0=32mm,絲杠軸端型式及尺寸已標(biāo)準(zhǔn)化,采用兩端固定式,可選用的軸承型號(hào)為 7205,內(nèi)徑 ? 外徑 ? 寬為 =25mm? 52mm? 12mm,額定動(dòng)載荷 C=,預(yù)加載荷F0=2900N,當(dāng)量載荷 Fm=. 則軸承壽命為 ????????? PCnL mh 60106 =533146915000h 其中 C= 軸承承受的載荷分別為 NYFXFP arx ??????? 當(dāng)量轉(zhuǎn)速 nm=100r/min 采 用球軸承 則 ? =3 故滿足要求。 聯(lián)軸器的選擇 為了減少振動(dòng)與沖擊帶來(lái)的負(fù)面影響,選用彈性套柱銷聯(lián)軸器,聯(lián)軸器的計(jì)算轉(zhuǎn)湖南工業(yè)大學(xué)本科畢業(yè)設(shè)計(jì)(論文) 33 矩 TKT Aca ?? 其中 公稱轉(zhuǎn)矩 T= mN? 工作情況系數(shù) AK = 則 TKT Aca ?? = mN? 查聯(lián)軸器樣本,選用 TL彈性套柱銷聯(lián)軸器,型號(hào)為 TL2,許用轉(zhuǎn)矩 [T]=16 mN? caT ,符合要求。采用的原料為鋼,許用轉(zhuǎn)速為 7600r/min,軸孔直徑為 14mm,軸孔長(zhǎng)度為20mm,轉(zhuǎn)子慣量 J= 2mkg? 。 電機(jī)的計(jì)算與選擇 ( 1)最大的切削負(fù)載轉(zhuǎn)矩 X軸最 大載荷 Fmax=,絲桿導(dǎo)程 Ph=10mm=,查絲杠樣本絲杠螺母副摩擦系數(shù) ? =, 摩擦力矩 mNTf ?? 。 查軸承樣本,單個(gè) 7205C型軸承的摩擦力矩為 320 mN? ,故一對(duì)軸承 mNTf ?? ,絲桿與伺服電動(dòng)機(jī)直接相聯(lián) ,故 i=1, 則最大切削負(fù)載轉(zhuǎn)矩 : NiTTPhFT ff a x 21 ???????? ???? ?????????? ???? ?? ( 2) 慣量匹配 負(fù)載慣量按下列次序計(jì)算,工臺(tái)的最大質(zhì)量為 20Kg,折算到電動(dòng)機(jī)軸其慣量 J1計(jì)算得: 2522221 mkgpmnnpmwvmJ hh ????????? ???????????????????????? ??? 絲杠直徑 d=32mm=,在結(jié)構(gòu)設(shè)計(jì)中,決定長(zhǎng)度 ,絲杠的慣量: 2104342 . mkgldJ ????????? ???? 聯(lián)軸節(jié)的慣量 J3可直接查手冊(cè) 243 mkgJ ??? ? J2 與 J3 與電動(dòng)機(jī)同軸 ,故能夠直接疊加,負(fù)載慣量: JL=J1+J2+J3=( ++) ? 104 2mkg? ≈ mkg ?? ? 湖南工業(yè)大學(xué)本科畢業(yè)設(shè)計(jì)(論文) 34 電動(dòng)機(jī)慣量 JM 應(yīng)符合的條件 JLJM4JL mkg ? JM mkg ? 根據(jù)以上計(jì)算,可初選伺服電動(dòng)機(jī),如選用直流伺服電動(dòng)機(jī), 可都選北京數(shù)控裝置廠 B8型, 它的額定轉(zhuǎn)矩為 mN? ,大于最大負(fù)載轉(zhuǎn)矩 T= mN? ,它的轉(zhuǎn)子慣量 JM= 2mkg? ( 3)空載加速轉(zhuǎn)矩 B8 型伺服電動(dòng)機(jī)的最大輸出轉(zhuǎn)矩為 Tmax=47 mN? ,這個(gè)輸出轉(zhuǎn)矩發(fā)生在階越指令加速時(shí),要求的加速時(shí)間為: maxmax602 TnJta ?? 其中 J =JL+JM= 410?? +45 410?? = 2mkg? 故 ?? ????at B8 的機(jī)械時(shí)間常數(shù)為 smstm ?? ,則 at ≤ (3~4)mt =(~) 說(shuō)明這種電動(dòng)機(jī)具 有足夠的加速能力 湖南工業(yè)大學(xué)本科畢業(yè)設(shè)計(jì)(論文) 35 結(jié) 論 本設(shè)計(jì)龍門式數(shù)控水刀切割機(jī)能高效、精確地完成 XY兩向移動(dòng)以及對(duì)材料進(jìn)行高壓水射流切割的功能。在給定 驅(qū)動(dòng)速度、射流最高切割壓力、水噴嘴直徑和系統(tǒng)流量的條件下,理論力學(xué)、材料力學(xué)、機(jī)械原理、機(jī)械設(shè)計(jì)、互換性與測(cè)量技術(shù)、工程圖學(xué)分析和公式計(jì)算最終選擇出滾珠絲杠螺母副型號(hào)為 FFZD6310— 5右旋;導(dǎo)軌選擇了 HSR— 20A、 LM直線滾動(dòng)導(dǎo)軌;軸承選擇 7010C 角接觸球軸承;電機(jī)采用 Y100L— 6驅(qū)動(dòng)電機(jī)型號(hào);聯(lián)軸器選用 YL10凸緣聯(lián)軸器。經(jīng)強(qiáng)度校核、壽命計(jì)算和穩(wěn)定性分析,得到滾珠絲 杠能達(dá)到 117 萬(wàn)次,最大動(dòng)載荷 ,最大靜載荷 ,剛度2505N/m,螺桿當(dāng)量應(yīng)力遠(yuǎn)小于許用值 68MPa,螺桿剪切應(yīng)力遠(yuǎn)小于許用值 30MPa,螺桿彎曲應(yīng)力遠(yuǎn)小于許用值 40MPa,穩(wěn)定性大于要求值 4因而合格,單個(gè)螺紋導(dǎo)程變形量小于最大值 ,最大轉(zhuǎn)速小于 ,以上表明絲杠符合選用要求。并且該龍門式數(shù)控水刀切割機(jī)能出色的完成切割任務(wù)。同時(shí)在傳動(dòng)系統(tǒng)使用了 45鋼、不銹鋼、 Q23 HT200、黃銅等,機(jī)床外觀使用了鑄鐵等材料。利用噴丸、滲碳處理,增強(qiáng)零件的硬度、耐磨性、剛度 等。我在此完成絲杠螺母副、直線滾動(dòng)導(dǎo)軌滑塊、聯(lián)軸器、軸承。電機(jī)的選用和設(shè)計(jì)。希望對(duì)其他人的后續(xù)設(shè)計(jì)能有幫助。 湖南工業(yè)大學(xué)本科畢業(yè)設(shè)計(jì)(論文) 36 致 謝 學(xué)生簽名: 日 期: 2022年 5月 20日 湖南工業(yè)大學(xué)本科畢業(yè)設(shè)計(jì)(論文) 37 參考文獻(xiàn) [1] 成大先 .機(jī)械設(shè)計(jì)手冊(cè) 1— 5卷[M].北京:機(jī)械工業(yè)出版社, . 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[15] 袁泳 . 數(shù)控切割機(jī)的應(yīng)用[R] . 建設(shè)機(jī)械技術(shù)與管理 . . 湖南工業(yè)大學(xué)本科畢業(yè)設(shè)計(jì)(論文) 38 您好,為你提供優(yōu)秀的畢業(yè)論文參考資料,請(qǐng)您刪除以下內(nèi)容, O(∩_∩)O 謝謝! ??!A national survey was recently launched to evaluate the eye health of Chinese children June 6, China39。s annual National Day for Eye Care, the China Youth Development ServiceCenter and Zhejiang Medicine, a leading listed Chinese pharmaceutical pany, jointlyannounced the kickoff of the s about one month, a questionnaire piled by top eye care medical experts in China willbe distributed through multiple online partners, including , as well asthrough offline survey events held in universities, middle schools and primary schools acrossthe report will be released based on the survey statistics and analysis, and most importantly,guidelines for parents and youth on how to care for the eyes and prevent myopia — agrowing problem in China39。s digitized society, will also be attached on the report.Myopia is not only a disease that makes people see things blurrily, but also leads to severeplications, such as glaua (increased pressure within the eyeball), and can causeblindness, said Zhou Yuehua, an established eye care specialist with Beijing TongrenHospital.It is very important for parents and children to know about the risk and care for their eyes.There are about 450 million myopia patients in China. Among Chinese myopia patients,30million are severe patients, according to ZhouThe prevalence of myopia among high school and college students is more than 70 percent,and the situation is continuously worsening, he Zhu, director with the China Youth Development Service Center, said long hours ofstudy, lack of exercise, especially outdoor activities, and attachment to electronic screen aresome of the top reasons behind the widespread myopia problems, and the increase ofyounger patients, although China has made great progress in improving the hardwarefacilities and lighting conditions in said he hopes the survey will alert people on the threatening situation, and also helpmedical experts to better guideline parents and children39。s behaviors to care for eyes, basedon the timely and factual statistics the survey series of followup events will also be held in six cities, including Jinan in Shandongprovince, and Changsha in Hunan province, to educate people on how to care for eyes afterthe survey started. More and more Chinese are jogging to get and stay fit. Most joggers will run alone, but some will jog with friends or ev