【正文】 適當(dāng)?shù)臐櫥蓽p少磨擦。凸輪可通過柄上的油孔或柄端上的潤滑裝置來潤滑。如果凸輪用來直接驅(qū)動機械組件，滾子就非常有效。如果凸輪傳到從動件的力不大，問題就不大嚴(yán)重。比如，滾子從動件可緊靠著擺動從動伯的邊緣作往復(fù)運動。從動件運動時與凸輪為幾何鎖合。凸輪旋轉(zhuǎn)使從動件移動。擺動從動件也可用于這種形式。圓柱凸輪有兩個突出特點：一個特點是：凸輪與從動件為幾何鎖合，不需要外力（如重力或彈簧力）將從動件貼緊凸輪工作面；第二個特點是：可在凸輪轉(zhuǎn)幾轉(zhuǎn)中，從動件完成一個完整循環(huán)。 圓柱凸輪，它使從動件產(chǎn)生往復(fù)運動。設(shè)計者應(yīng)仔細(xì)分析從動件受力的水平力分量，因為它們會使從動件的導(dǎo)向出現(xiàn)問題。 推桿的運動規(guī)律 （ 1）凸輪機構(gòu)的運動循環(huán)及基本名詞術(shù)語 推程運動角：與從動件推程相對應(yīng)的凸輪轉(zhuǎn)角； 遠(yuǎn)休止角 ： 與從動件遠(yuǎn)休程相對應(yīng)的凸輪轉(zhuǎn)角； 回程運動角：與從動件回程相對應(yīng)的凸輪轉(zhuǎn)角； 近休止角 ： 與從動 件近休程相對應(yīng)的凸輪轉(zhuǎn)角； 凸輪基圓 ： 以凸輪軸心為圓心 ,以其輪廓最小向徑 r0 為半徑的圓； 從動件行程 : 在推程或回程中從動件的最大位移 ,用 h 表示； 偏 距 : 凸輪回轉(zhuǎn)中心與從動件導(dǎo)路間的偏置距離 ,用 e 表示。 凸輪機構(gòu)的應(yīng)用 凸輪機構(gòu)是含有凸輪的高副機構(gòu)，凸輪機構(gòu)具有結(jié)構(gòu)簡單，可以準(zhǔn)確實現(xiàn)要求的運動規(guī)律等優(yōu)點，因而在工業(yè)生產(chǎn)中得到廣泛的應(yīng)用，特別是自動機械和自動控制裝置中，得到廣泛的應(yīng)用。 3. 凸輪機構(gòu)基本參數(shù)設(shè)計，確定從動件行程、各運動角、凸輪基圓半徑、偏距、滾子半徑、中心距、從動件長度等。對于高速凸輪，為了減小慣性力的危害，應(yīng)選擇 amax值較小的運動規(guī)律。若從動件突然被阻止，過大的動量會導(dǎo)致極大的沖擊力，危及設(shè)備和人身安全。最簡便的方法是采用緊定螺釘固定凸輪，或用緊定螺釘預(yù)固定，待調(diào)整好后再用銷子固定。當(dāng)工作載荷較小時，曲線輪廓的軸向厚度一般取為輪廓曲線最大矢徑的 1/10～ 1/5；對于受力較大的重要場合，需按凸輪輪廓面與從動件間的接 觸強度進(jìn)行設(shè)計。 3． 用座標(biāo)尺寸設(shè)計。 凸輪輪廓可用作圖法或數(shù)學(xué)計 算法來精確設(shè)計，將設(shè)計圖轉(zhuǎn)換成加工圖可用下面幾種方法： 1． 制造一個實尺樣板。最常用的凸輪是盤形凸輪。許多計時裝置由凸輪驅(qū)動。the slot cam then engage a pin or roller on a guided vertical reciprocated the latter type ,however,a plete force analysis is a critical phase of the design. In this type,the cam rotates and the follower (ususlly a roller or pin) is guided by a groove cut into the end face of a cylindrical section .Rotation of the cam provides translation of the type is also positive costs for this type of cam are much higher than for a simple plate cam. A constant –diameter cam is illustrated .This is merely a circular plate with the camshaft hole eccentrically amount of eccentricity determines the amount of follower the cam rotates,the follower arrangement is sometimes known as a Scotch yoke action is positive 。 Cam: Take the cam axle center as the center of a circle, take its outline slightly to diameter r0 as the radius circle。 (2) roller from (3) flat base from. Note: Classifies this part of content when the introduction cam gear, should point out each kind of cam gear the good and bad points and its the adaption situation, showed each kind of cam gear the inner link, will build the foundation for the later translation cam and the column cam contour design. 3rd, the throwout lever movement rule (1) the cam gear cycle of motion and the basic term terminology push the regulation movement angle: With from pushes the cam corner which the regulation corresponds。a secondary follower is often .used to produce additional displacement in another most popular type is the plate cylindrical type is used to transmit linear motion to a follower as the cam cam are sometimes used。these provide some unusual follower motions,but also make follower design camshaft in the automotive engine illustrates a simple but important application of a late cam assemblies in automatic record players illustrate a somewhat more plex application. Cam profiles are accurately constructed by either praphical or mathematical transitiom from developmen