畢 業(yè) 設(shè) 計(jì)（論文）題目：履帶拖拉機(jī)無(wú)級(jí)變速器設(shè)計(jì)（操縱機(jī)構(gòu)設(shè)計(jì)）姓 名: 院 系: 專 業(yè): 指導(dǎo)教師: 摘要拖拉機(jī)工作條件復(fù)雜，外界負(fù)荷復(fù)雜多變，要求發(fā)動(dòng)機(jī)或變速器能適時(shí)的改 變轉(zhuǎn)矩的大小或轉(zhuǎn)速，以保證拖拉機(jī)的動(dòng)力性和經(jīng)濟(jì)性。傳統(tǒng)變速箱雖能通過(guò)換擋達(dá)到一定的要求，但其檔位有限，無(wú)法實(shí)現(xiàn)無(wú)級(jí)變速。液壓機(jī)械無(wú)級(jí)變速器（ HMCVT）是一種液壓功率流與機(jī)械功率流并聯(lián)的新型轉(zhuǎn)動(dòng)裝置，液壓機(jī)械無(wú)級(jí)變速器是綜合了機(jī)械傳動(dòng)高效率和液壓傳動(dòng)無(wú)級(jí)變速兩方面優(yōu)點(diǎn)的新型傳動(dòng)機(jī)構(gòu)。液壓機(jī)械無(wú)級(jí)傳動(dòng)是一種多功率流傳動(dòng)系統(tǒng)，它將功率分為液壓和機(jī)械兩路傳遞即功率分流，分流機(jī)構(gòu)分流后液壓馬達(dá)在正向和反向最大速度之間來(lái)回?zé)o級(jí)變速。其每一個(gè)行程和行星齒輪機(jī)構(gòu)的一種工況相配合，最后，兩路匯合成由若干無(wú)級(jí)調(diào)速段相銜接并組逐段升高的全程無(wú)級(jí)輸出速度。液壓元件只負(fù)擔(dān)最大功率的一部分，其他功率都由機(jī)械路傳遞。這相當(dāng)于將液壓無(wú)級(jí)變速功率擴(kuò)大，傳動(dòng)總效率相對(duì)于液壓傳動(dòng)也顯著提高，和液力機(jī)械傳動(dòng)相比，裝載量最大可提高 30%，燃油經(jīng)濟(jì)性最大可提高 25%。其特點(diǎn)是通過(guò)機(jī)械傳動(dòng)實(shí)現(xiàn)功率轉(zhuǎn)遞，通過(guò)液壓機(jī)械相結(jié)合實(shí)現(xiàn)無(wú)級(jí)變速。目前，國(guó)外先進(jìn)的拖拉機(jī)，工程車輛已經(jīng)采用液壓無(wú)級(jí)變速器。馬達(dá)的最高轉(zhuǎn)速對(duì)應(yīng)著該段的末速度，當(dāng)這段的末速度等于后一段的初速度及后一段初速度對(duì)應(yīng)馬達(dá)最高轉(zhuǎn)速位置。此液壓機(jī)械無(wú)級(jí)變速器必須與發(fā)動(dòng)機(jī)合理匹配才能發(fā)揮其優(yōu)勢(shì)。匹配的關(guān)鍵是根據(jù)各種路況和發(fā)動(dòng)機(jī)特性調(diào)節(jié)變速器的傳動(dòng)比，使發(fā)動(dòng)機(jī)工作在最佳狀態(tài)。 我國(guó)是一個(gè)人均能源，資源貧乏的發(fā)展中國(guó)家，提高燃油的經(jīng)濟(jì)性尤為重要。目前，我國(guó)在這方面的研究處于理論研究階段。關(guān)鍵詞：功率分流，匹配,燃油的經(jīng)濟(jì)性。ABSTRACTTractor working conditions complicated complex and ever-changing external load. Engine request or timely transmission of torque to change the size or speed to ensure that the tractor power and economy. Although traditional gearbox through shifting to reach a certain standard, but its gear is limited and they can not achieve CVT.Hydraulic machinery CVT (HMCVT) is a power flow of hydraulic and mechanical power flow parallel to the new rotation device , hydraulic machinery CVT is a synthesis of highly efficient mechanical transmission and hydraulic drive CVT merits of the two new drive institutions. Hydro-Mechanical - drive is a multi-stream transmission, power will be divided into two hydraulic and mechanical way that the power transfer streaming streaming agencies triaged hydraulic motor in forward and reverse maximum speed between both CVT. Each of its itinerary and a planetary gear mechanism for a state match, finally, Road converge into two by a number of variable speed converge and the group has to absolutely no higher level of output speed changes. Hydraulic Components burden only part of the maximum power, the other by mechanical power transmission path. This will be the equivalent of continuously variable hydraulic power expansion drive efficiency relative to the total hydraulic transmission has improved significantly. hydraulic and mechanical transmission, the loading capacity can be increased by 30%, fuel economy can be increased 25%. Its characteristics are achieved through mechanical transmission transmit power through the combination of hydraulic machinery to achieve CVT.Currently, foreign advanced tractors, construction vehicles using hydraulic CVT. Motor corresponding to the maximum speed of the speed at the end, When this speed to the end after a period of the early speed and after a period of initial velocity corresponding maximum speed motor position. This hydraulic mechanical CVT engine with a reasonable match to play to their strengths. Matching is the key to all kinds of traffic regulation and the engine characteristics of the transmission ratio transmission, the engine work in the best condition.China is a per capita energy and resource-poor developing countries, to increase fuel economy is particularly important. Currently, our research in this area in theoretical research stage.KEY WORD : power streaming CVT, matching ,fuel economy.目 錄第一章 緒論. 1第二章 液壓機(jī)械無(wú)級(jí)變速器傳遞方案的確定.2§2.1 液壓機(jī)械無(wú)級(jí)傳動(dòng)的原理及特點(diǎn)2§2.1.1 液壓傳動(dòng)原理2§2.1.2 液壓傳動(dòng)特點(diǎn)3§2.2 液壓機(jī)械無(wú)級(jí)變速器傳遞方案的選擇3第三章 液壓泵－液壓馬達(dá)調(diào)速油路的設(shè)計(jì)6§3.1 變量泵與定量馬達(dá)排量的確定 .6§3.1.1 變量馬達(dá)—定量泵所組成的油路6§3.1.2 補(bǔ)油泵的選擇 .8§3.1.3 液壓油及油管的選擇9§3.2 液壓油路壓力損失的確定 9§3.2.1 液壓油流動(dòng)狀態(tài)的確定 9§3.2.2 油路沿途壓力損失的計(jì)算 9§3.2.3 局部壓力損失10§3.3 油箱尺寸的確定 10§3.4 液壓元件的選擇.11第四章 液壓機(jī)械無(wú)級(jí)變速器液壓控制油路設(shè)計(jì)13§4.1 油路設(shè)計(jì).13§4.1.1 冷卻與潤(rùn)滑油路.13§4.1.2 液壓元件的選擇14§4.2 液壓機(jī)械無(wú)級(jí)變速控制原理.14§4.2.1 經(jīng)濟(jì)性換擋. .15§4.2.2 動(dòng)力性換擋 17第五章 結(jié)論.21參考文獻(xiàn).22致謝.24