【正文】 此外﹐由 于 其齒根厚度較大﹐雙圓弧齒輪傳動(dòng)不僅承載能力比單圓弧齒輪傳動(dòng)約高 30％以上﹐而且傳動(dòng)較平穩(wěn)﹐振動(dòng)和噪聲較小﹐并且可用同一把滾刀加工相配對(duì)的兩個(gè)齒輪。圓弧齒輪傳動(dòng)的特點(diǎn)是﹕ (1)綜合曲率半徑比漸開線齒輪傳動(dòng)大很多﹐其接觸強(qiáng)度比漸開線齒輪傳動(dòng)約高 ～ ﹔ (2)兩輪齒沿 嚙合 線方向的滾動(dòng)速度很大﹐齒面間易 于 形成油膜﹐傳動(dòng)效率較高﹐一般可達(dá) ～ ﹔ (3)圓弧齒輪沿齒高方向磨損均勻﹐且容易跑合﹔ (4)圓弧齒輪無根切現(xiàn)象﹐故最小齒數(shù)可以少。3 …… 各點(diǎn)依次沿 嚙合 線接觸。 單圓弧齒輪傳動(dòng) 小齒輪的凸齒工作齒廓在節(jié)圓以外﹐ 齒廓圓心在節(jié)圓上﹔大齒輪的凹齒工作齒廓在節(jié)圓內(nèi)﹐齒廓圓心略偏 于 節(jié)圓以外。它還具有結(jié)構(gòu)緊湊，最小齒數(shù)可做到兩齒等優(yōu)點(diǎn)。設(shè)齒輪副的中心距為 l，節(jié)圓半徑同為 l/2，偏差函數(shù)選 ) os (4)(11 ??? ?? le （ 19） ) os () os (4c os21111 ????? ???? llg x ) i n() os (4c os21111 ????? ???? llg y （ 20） 圖 5 描繪了上述齒輪齒廓的連續(xù)凸凹接觸特性，它的重合系數(shù)為 。 3）構(gòu)造齒廓。 與其它內(nèi)嚙合齒輪相似，變圓弧齒輪也存在對(duì)誤差敏感等問題。1 1 er e???? 從上述公式可知，齒面接觸應(yīng)力的大小與接觸點(diǎn)處曲率半徑的差成正比，齒根彎曲應(yīng)力和齒面接觸應(yīng)力都與生成齒廓的偏差函數(shù)有關(guān)，因此，通過合理設(shè)計(jì)變圓弧齒輪的偏差函數(shù)，我們能夠獲得所需的齒根彎曲強(qiáng)度 和表面接觸強(qiáng)度。212 )/( ?? （ 18） 239。 根據(jù) Hertz 接觸應(yīng)力理論，假設(shè)兩個(gè)齒輪采用相同的材料制造，內(nèi)嚙合齒廓在接觸點(diǎn) g 處的接觸應(yīng)力計(jì)算公式為 21212 )1(2ggggnH vL EF ?? ???? ??? （ 16） 式中 ρg1 ρg2分別為兩齒廓在接觸 點(diǎn)處的曲率半徑，它們的計(jì)算公式分別為 eerg ???39。 3 變圓弧齒輪齒廓的特點(diǎn) 從理論上講，變圓弧齒輪包括外嚙合齒輪副和內(nèi)嚙合齒輪副。 兩齒廓嚙合過程中保持接觸的條件是齒廓 c1上的 g 點(diǎn)速度 Vg1和齒廓 c2上的 g 點(diǎn)速度 Vg2在公法線方向的速度分量相等，即 vgn1=vgn2；從齒廓的生成原理可知，兩齒輪的齒廓在任意嚙合點(diǎn) g 處存在公法線 nn′它與連心線 O1O2交于節(jié)點(diǎn) P，由 O1和 O2點(diǎn)分別向 nn′作垂線，交于 n1和 n2點(diǎn)，則 ， 1111 nowvgn ?? 2222 nowvgn ?? 如圖 3，則傳動(dòng)比為 tc onspopononowwi t a n// 12112221 ???? （ 12） 因此，我們得出結(jié)論：變圓弧齒輪能夠?qū)崿F(xiàn)恒定轉(zhuǎn)速比傳動(dòng)。 （ 4）為了保證齒廓光順，在 e（ θ1）最小、最大值之間必須單調(diào)變化。1 ?? ??rL )(tan 239。 當(dāng)取偏差函數(shù) e（ θ 1） =r1cosα (θ ） 時(shí)，變圓弧齒廓就是常見的漸開線齒廓；而當(dāng)偏差函數(shù)取 )2sin(2)( 10101 ?? rrre ? 時(shí)，這時(shí)的變圓弧齒廓就是擺線齒廓；而對(duì)于普通圓弧齒輪來說，相當(dāng)于偏差函數(shù) e（ θ1）只在某些離散點(diǎn)取值。文中介紹了變圓弧齒輪的形成原理，推導(dǎo)了齒廓計(jì)算公式，討論了變圓弧齒輪的特性，給出了齒廓實(shí)例。 關(guān)鍵詞： 齒輪 齒廓 偏差函數(shù) 嚙合原理 齒輪 強(qiáng)度 引言 隨著科學(xué)技術(shù)的發(fā)展，對(duì)齒輪傳動(dòng)的要求也不斷提高，特別在重載和小型化方面尤為突出。3…… points followed along the lines mesh contact. Therefore, the arc gear concave surface of the end Tooth Profile ﹑ convex only for instantaneous meshing. A new circular gear in theory is instantaneous point engagement, the circular drive is often called the meshing gear transmission point arc. After runninggear, in fact tooth profile to high gear along with a rather long period of exposure. Arc gear transmission is characterized by: (1) prehensive than the radius of curvature involutes gear transmission much bigger, than the intensity of their contact with involutes gear transmission of about to times (2) two teeth along the direction of the meshing Rolling great speed, easytooth surface of a Film, transmission more efficient, generally up to to (3) arc high gear along the direction of tooth wear uniform, and easy to run a (4) the arc gear without undercutting Phenomenon, the smallest teeth can be less. But for Gear arc from the center of spiral ﹑ Cutting depth and angle of error of great sensitivity, the three errors on a greater impact on carrying capacity, the circular gear on the manufacture and installation of high accuracy. In addition, singlearc Gear bending strength weak samecutting ﹑ large number of small gear, needed two different hob. Double arc gear transmission work, from one end, the first tooth of the Au initiative to promote the Department of the Ministry of convex follower of the tooth, left, and then to its convex promote each other39。 big ﹑ small gear in their respective sections outside the circle of the teeth are made convex arc Profile in the section within the circle are made part of the Au arc tooth profile, said double arc gear transmission. Arcgear transmission gear of the small convex teeth tooth profile in the work of a round, the Tooth in the central section circle。2139。1239。 teeth in two parts, a 39。 for vertical, the TAC in n1, n2 and, 1111 nowvgn ?? 2222 nowvgn ?? Figure 3, the transmission ratio for the tc on spopononowwi tan// 12112221 ???? (12) Therefore, we concluded: Arc gear change can be achieved than the constant speed drive. Variable Arc gear tooth profile of the relative speed of sliding )1()( 21121 rreev rs ???? ??? （ 13） )(tan2 239。2139。1erebac??? ? bacoaooao ??????? 11111 )( ???? )2/0( 1 ?? ?? （ 3） In order to get the tooth profile to the practical application, the deviation must also function e(θ1) the choice to do certain restrictions (1) To ensure the tooth profile of noncrossing to |)cos(| 11 ?re ? （ 4） (2) To ensure that equation (3) Solution for 21239。39。 such gear has a high carrying capacity, especially for hig