推土機(jī)液壓系統(tǒng)設(shè)計(jì)3張CAD圖,推土機(jī),液壓,系統(tǒng),設(shè)計(jì),CAD 附錄: 推土機(jī) 推土機(jī)是土方工程機(jī)械的一種主要機(jī)械，按行走方式分為履帶式和輪胎式兩種.因?yàn)檩喬ナ酵仆翙C(jī)較少。本文主要講述履帶式推土機(jī)的結(jié)構(gòu)與工作原理。功率大于 120KW 的履帶式推土機(jī)中，絕大多數(shù)采用液力-機(jī)械傳動(dòng)。這類推土機(jī)來源于引進(jìn)日本小松制作所的 D155 型、D85 型、D65 型三種基本型推土機(jī)制造技術(shù)。國(guó)產(chǎn)化后，定型為 TY320 型、TY220 型、TY160 型基本型推土機(jī)。為了滿足用戶各種使用工作況的需求，我國(guó)推土機(jī)生產(chǎn)廠家在以上三個(gè)基本型推土機(jī)的基礎(chǔ)上，拓展了產(chǎn)品品種，形成了三種系列的推土機(jī)。TY220 型推土機(jī)系列產(chǎn)品，包括 TSY220 型濕地推土機(jī)、TMY220 型沙漠推土機(jī)、TYG220 型高原推土機(jī)、TY220F 型森林伐木型推土機(jī)、TSY220H 型環(huán)衛(wèi)推土機(jī)和 DG45 型吊管機(jī)等。TY320 型和 TY160 型系列推土機(jī)也在拓展類似的系列產(chǎn)品。 TY160 系列中還有 TSY160L 型超濕地推土機(jī)和 TBY160 型推扒機(jī)等。 推土機(jī)產(chǎn)品種的開發(fā)拓展，既要滿足不同工況條件的工作適應(yīng)性，又必須與基本型保持最大限度的零部件通用性(或稱互換性)，這就為廣大用戶使用維修帶來極大的方便。為方便用戶購(gòu)買配件，生產(chǎn)廠都保留了日本小松公司的零部件編號(hào)，只有改型中自行設(shè)計(jì)的零部件，才冠以自己廠家的編號(hào)。履帶式推土機(jī)主要由發(fā)動(dòng)機(jī)、傳動(dòng)系統(tǒng)、工作裝置、電氣部分、駕駛室和機(jī)罩等組成。其中，機(jī)械及液壓傳動(dòng)系統(tǒng)又包括液力變矩器、聯(lián)軸器總成、行星齒輪式動(dòng)力換擋變速器、中央傳動(dòng)、轉(zhuǎn)向離合器和轉(zhuǎn)向制動(dòng)器、終傳動(dòng)和行走系統(tǒng)等。動(dòng)力輸出機(jī)構(gòu)(PTO)10 以齒輪傳動(dòng)和花鍵連接的方式帶動(dòng)工作裝置液壓系統(tǒng)中工作泵 P1、變速變矩液壓系統(tǒng)變速泵 P2、轉(zhuǎn)向制動(dòng)液壓系統(tǒng)轉(zhuǎn)向泵 P3；鏈輪 8 代表二級(jí)直齒齒輪傳動(dòng)的終傳動(dòng)機(jī)構(gòu)(包括左和右終傳動(dòng)總成)；履帶板 9 包括履帶總成、臺(tái)車架和懸掛裝置總成在內(nèi)的行走系統(tǒng)。 本文將重點(diǎn)介紹上述傳動(dòng)系統(tǒng)中的液力變矩器、行星齒輪式動(dòng)力換擋變速器、轉(zhuǎn)向離合器和轉(zhuǎn)向制動(dòng)器的結(jié)構(gòu)、工作原理及其液壓系統(tǒng)的故障及排除。國(guó)產(chǎn) 102KW 以下的推土機(jī)，如 T140 型、T120 型、T70 型等小功率推土機(jī)，其傳動(dòng)系統(tǒng)的型式都是機(jī)械傳動(dòng)的，包括離合器和機(jī)械變速器等。這類推土機(jī)在我國(guó)產(chǎn)銷量也較大； 其結(jié)構(gòu)較為簡(jiǎn)單，生產(chǎn)年代較早，使用單位較熟悉，使用維修也比較容易。 1、液力變矩器 該變矩器為三元件向心渦輪式，結(jié)構(gòu)簡(jiǎn)單、傳動(dòng)效率高。變矩器由泵輪組件、渦輪組件、導(dǎo)輪組件三部分構(gòu)成。泵輪組件中的泵輪由螺栓和驅(qū)動(dòng)殼連接，驅(qū)動(dòng)齒輪由螺栓和驅(qū)動(dòng)殼連接。驅(qū)動(dòng)齒輪直接插入發(fā)動(dòng)機(jī)飛輪齒圈內(nèi)，故泵輪隨發(fā)動(dòng)機(jī)一起旋轉(zhuǎn)。導(dǎo)輪由螺栓和導(dǎo)輪轂連接，導(dǎo)輪轂通過花鍵和導(dǎo)輪座連接，導(dǎo)輪座又通過螺栓和變矩器殼連接，故導(dǎo)輪和變矩器殼一起，是不旋轉(zhuǎn)的。渦輪和渦輪轂用鉚釘鉚接在一起，再通過花鍵和渦輪輸出軸連接，渦輪輸出軸通過花鍵和聯(lián)軸節(jié)連接，將動(dòng)力傳遞給其后的傳動(dòng)系統(tǒng)。泵輪隨發(fā)動(dòng)機(jī)一起旋轉(zhuǎn)，將動(dòng)力輸入， 導(dǎo)輪不旋轉(zhuǎn)，渦輪旋轉(zhuǎn)，將動(dòng)力輸出，三者之間相互獨(dú)立，輪間間隙約為 2mm。泵輪、渦輪、導(dǎo)輪自身由許多葉片組成，稱之為葉柵，葉片由曲而構(gòu)成，呈復(fù)雜的形狀。變矩器在工作時(shí)，葉柵中是需要充滿油液的，在泵輪高速旋轉(zhuǎn)時(shí)，泵輪葉柵中的油液在離心力的作用下沿曲面向外流動(dòng)，在葉柵出口處射向渦輪葉柵出口， 然后沿渦輪葉柵曲面作向心流動(dòng)，又從渦輪葉柵出口射向?qū)л喨~柵進(jìn)口，穿過導(dǎo)輪葉柵又流回泵輪。泵輪、渦輪、導(dǎo)輪葉柵組成的圓形空間，稱之為循環(huán)圓。由于渦輪葉柵曲面形狀的設(shè)計(jì)，決定了渦輪和泵輪在同一方向旋轉(zhuǎn)。這樣，變矩器葉柵循環(huán)圓中的油液，一方面在循環(huán)圓中旋轉(zhuǎn)，一方面又隨泵輪和渦輪旋轉(zhuǎn)，從而形成了復(fù)雜的螺旋運(yùn)動(dòng)，在這種運(yùn)動(dòng)中，將能量從泵輪傳遞給渦輪。渦輪的負(fù)荷是推土機(jī)負(fù)荷決定的。推土機(jī)的負(fù)荷由鏟刀傳遞給履帶行走系統(tǒng)，再傳給終傳動(dòng)、轉(zhuǎn)向離合器、中央傳動(dòng)、變速器和聯(lián)軸器總成，最終傳遞給變矩器渦輪。渦輪負(fù)荷小時(shí)，其旋轉(zhuǎn)速度就快；負(fù)荷大時(shí)，旋轉(zhuǎn)速度就慢。當(dāng)推土機(jī)因超載走不動(dòng)時(shí)，渦輪的轉(zhuǎn)速也下降為 0，成為渦輪的制動(dòng)狀態(tài)。這時(shí)，因渦輪停止轉(zhuǎn)動(dòng)，由泵輪葉柵射來的油液，以最大的沖擊穿過渦輪葉柵沖向?qū)л?，在不轉(zhuǎn)的導(dǎo)輪葉柵中轉(zhuǎn)換成壓力，該壓力反壓向渦輪，增大了渦輪的扭矩，該增加的扭矩和渦輪旋轉(zhuǎn)方向一致，此時(shí)渦輪輸出扭矩最大，為泵輪扭矩的 2.54 倍。渦輪隨著負(fù)荷增大， 轉(zhuǎn)速逐漸降低，扭矩逐漸增加，這相當(dāng)于一個(gè)無級(jí)變速器在逐漸降速增扭。這種無級(jí)變矩的性能與易操縱而擋位較少的行星齒輪式動(dòng)力換擋變速器相配合，使推土機(jī)獲得了優(yōu)異的牽引性能。 液力變矩器是依靠液力工作的。油液在葉柵中流動(dòng)時(shí)，由于沖擊、摩擦，會(huì)消耗能量，使油發(fā)熱，故液力變矩器的傳動(dòng)效率是較低的。目前，國(guó)內(nèi)外最好的液力變矩器其最高效率為 88%。當(dāng)變矩器的渦輪因推土機(jī)超負(fù)荷而停止轉(zhuǎn)動(dòng)時(shí)，由泵輪傳來的能量全部轉(zhuǎn)化成熱量而消耗掉，此時(shí)變矩器效率為 0。要想提高變矩器的傳動(dòng)效率，就要掌握推土機(jī)的負(fù)荷，使渦輪有適當(dāng)?shù)霓D(zhuǎn)速、推土機(jī)有適當(dāng)?shù)乃俣?；即?dāng)推土機(jī)因負(fù)荷過大而走不動(dòng)時(shí)，要及時(shí)減小負(fù)荷，提一下鏟刀或由 II 擋換為 I 擋。 由變矩器的結(jié)構(gòu)和工作原理知，變矩器工作時(shí)油會(huì)有內(nèi)泄、會(huì)發(fā)熱。這就要求要及時(shí)給變矩器內(nèi)部補(bǔ)充油，并將發(fā)熱的油替換出來冷卻，形成一個(gè)循環(huán)。TY320 型和 TY220 型有完全相似的液力變矩器，只是進(jìn)行了幾何放大。TY160 型和 TY220 型有基本相似的的液力變矩器，人是結(jié)構(gòu)有些變化。它們的故障和維修是基本相同的。 2、行星齒輪式動(dòng)力換擋變速器 該變速器主要由四個(gè)行星排和一個(gè)旋轉(zhuǎn)閉鎖離合器構(gòu)成。上多轉(zhuǎn)輸出的行星齒輪減速機(jī)構(gòu)。TY220 型推土機(jī)變速器即利用第 II 行星排作為倒擋使用。離合器有 5 個(gè)。第 1 至第 4 離合器的油缸體由螺栓連接在端蓋上，它們是不運(yùn)動(dòng)的。當(dāng)油缸體和活塞之間充滿壓力油時(shí)，壓力油在油超過計(jì)劃的密封下，建立油壓并推活塞壓緊摩擦片，則可將齒圈固定。 旋轉(zhuǎn)閉鎖離合器的結(jié)構(gòu)比較特殊，它沒有行星機(jī)構(gòu)，其工作時(shí)是整體旋轉(zhuǎn)的。向旋轉(zhuǎn)油缸中供油時(shí)，需先向中心軸供油。工作時(shí)，壓力油通過第 5 離合器固定不動(dòng)的殼體 19 中的油道，進(jìn)入旋轉(zhuǎn)油缸，推動(dòng)活塞工作。為防止泄漏，要用旋轉(zhuǎn)密封環(huán)進(jìn)行密封。工作完的油液，由于旋轉(zhuǎn)油缸不停地旋轉(zhuǎn)，離心力向外甩出， 無法經(jīng)供油道排出，會(huì)增加摩擦片的磨損。為解決此問題，在旋轉(zhuǎn)油道排出，會(huì)增加摩擦片的磨損。為解決此問題，在旋轉(zhuǎn)油缸體上增加一個(gè)鋼球止回閥，在壓力油的作用下，它密封油孔以建立油壓，停止供油時(shí)，它會(huì)甩開，開放回油孔以回油。 TY220 型推土機(jī)變速器，在結(jié)構(gòu)上許多特點(diǎn)，利用這些特點(diǎn)，可使維修更為容易進(jìn)行。如第 1 至第 4 離合器的摩擦片和光盤都是通用的；第 2 至第 4 行星排的活塞和密封環(huán)相同，行星排離合器導(dǎo)向銷相同，光盤分離彈簧相同，離合器活塞分離彈簧相同；第 1 至第 3 行星排使用同一個(gè)行星架；第 4 行星排的行星架利用外齒圈插入第 3 行星排齒圈中，并用彈簧卡圈防止軸向竄動(dòng)等等。 TY320 和 TY220 型推土機(jī)系列產(chǎn)品有完全相似的變速器，只是放大了幾何尺寸。TY160 型推土機(jī)變速器，離合器的排列方式不同，第 1 離合器為前進(jìn)擋，第 2 離合器為后退擋，第 3 旋轉(zhuǎn)閉鎖離合器為 I 擋，第 4 離合器為 III 擋，第 5 離合器為 II 擋。安們有相同的使用維修特點(diǎn)。 3、轉(zhuǎn)向離合器和轉(zhuǎn)向制動(dòng)器 變速器的動(dòng)力傳入中央傳動(dòng)后，就從縱向傳動(dòng)變?yōu)闄M向傳動(dòng)，由橫軸分別傳給左、右兩個(gè)轉(zhuǎn)向離合器。該機(jī)的轉(zhuǎn)向離合器是彈簧壓緊、液壓分離、常嚙合、溫式摩擦片結(jié)構(gòu)型式。它包括外鼓、內(nèi)鼓、壓盤、外摩擦片、內(nèi)齒處、活塞、螺栓、套筒與活塞連接成一個(gè)整體大、小彈簧支撐在內(nèi)鼓上，彈簧的安裝負(fù)荷推動(dòng)活塞向右移動(dòng)，帶動(dòng)壓板將摩擦片和齒片壓緊在一起，實(shí)現(xiàn)接合傳力。彈簧共 8 組，總安裝負(fù)荷 3.2T，有足夠的壓力壓緊摩擦片以傳遞力矩。當(dāng)推土機(jī)需要轉(zhuǎn)向(如拉動(dòng)左轉(zhuǎn)向拉桿)時(shí)，淮壓油充入轉(zhuǎn)向離合器活塞和輪轂之間的油腔，油壓力推動(dòng)活塞，帶動(dòng)壓盤向左移動(dòng)，摩擦片和齒片松開，不再傳遞力矩，推土機(jī)左側(cè)失去動(dòng)力，在右側(cè)履帶的推動(dòng)下向左轉(zhuǎn)向。轉(zhuǎn)向結(jié)束時(shí)，松開拉桿，液壓油在活塞推動(dòng)下回流，轉(zhuǎn)向離合器重新接合傳力，推土機(jī)恢復(fù)直線行駛。 TY220 型推土機(jī)轉(zhuǎn)向制動(dòng)器是液壓助力、浮動(dòng)濕式制動(dòng)帶式。它包括安裝在轉(zhuǎn)向離合器外鼓上的制動(dòng)帶、助力活塞、連桿、浮動(dòng)桿、連桿等零件。由于浮動(dòng)機(jī)構(gòu)的優(yōu)越性能，不論離合器外鼓是正轉(zhuǎn)還是反轉(zhuǎn)，制動(dòng)時(shí)都很平穩(wěn)，不會(huì)產(chǎn)生制動(dòng)沖擊。當(dāng)制動(dòng)帶 1.5 上的制動(dòng)帶襯片 16 磨損后，制動(dòng)帶和外鼓之間間隙變大， 制動(dòng)跳板行程增加，當(dāng)行程增大到一定限度時(shí)，制動(dòng)變得不可靠。因此，要不斷地調(diào)整制動(dòng)帶間隙。 Bulldozer Bulldozer is one of the earthwork construction machinery mainly machinery, divided into two kinds of crawler and wheel by walking pattern. Because of less tyred bulldozer. This article mainly tells about the structure and working principle of crawler bulldozer. Power is greater than 120 kw crawler bulldozers, the vast majority of the hydraulic - mechanical transmission. This kind of bulldozer is derived from the introduction of Japan komatsu D155, D85, D65 type three basic bulldozers manufacturing techniques. After localization, finalize the design for TY320, TY220, TY160 bulldozer of basic types. In order to meet user's demand to all kinds of using work conditions, the bulldozers manufacturer in China, on the basis of the above three basic bulldozers, expand the varieties of products, has formed three series of bulldozer. Type TY220 bulldozer series products, including TSY220 wetland type bulldozer bulldozers, TMY220 bulldozers, TYG220 desert plateau, TY220F forest logging bulldozers, TSY220H sanitation bulldozers and DG45 sideboom, etc.TY320 series and TY160 bulldozer in similar series products. TY160 series and TSY160L super wetland bulldozers and TBY160 pick machine, etc. Bulldozers, develop the new product a, should not only meet the work adaptability of different working condition, and must maintain maximum parts commonality with the basic (or replacement), it is to use maintenance bring great convenience for the masses of users. Factories are retained for the convenience of users to buy accessories, Japan komatsu parts number, only in the retrofit design of parts andcomponents, just as their manufacturer's serial number. Crawler type dozer is mainly composed of engine, transmission system, working device, electric parts, cab and hood, etc. Among them, the mechanical and hydraulic transmission system, including hydraulic torque converter, coupling assembly, planetary gear type power shift transmission, the transmission, steering clutches and steering brakes, final drive and walking system, etc. Power output mechanism (the office) 10, in the form of gear and spline connection drives the work device of the hydraulic system work in P1 pump, variable speed hydraulic system of torque speed pump P2, P3 steering braking hydraulic system of steering pump; Sprocket 8 representative level of spur gear drive transmission mechanism (including the left and the right of final drive assembly); 9 segments including crawler assembly, chassis and suspension assembly, walking system. This article focuses on the transmission system of the hydraulic torque converter, planet gear type power shift transmission, steering clutch and brake the structure, working principle and the faults of hydraulic system and ruled out. Domestic below 102 kw of bulldozer, such as T140, T120 and T70 type small power bulldozers, its transmission system model are the mechanical transmission, including clutch and mechanical transmission, etc. This kind of bulldozer production in our country also larger; Earlier, its structure is simple, the production s unit using a familiar, use maintenance is also easier. 1, the hydraulic torque converter The centripetal turbine torque converter for the three components, simple structure, high transmission efficiency.A torque converter by the pump wheel and turbine components, guide pulley components, three parts. Parts of the pump is driven by the bolt and pump wheel shell connection, drive gear are connected by a bolt and drive shell. Drive gear directly inserted into the engine flywheel ring gear, so the pump wheel rotate with the engine. Wheel are connected by a bolt and guide wheel, guide wheel by spline and idler pulley seat connection, idler pulley block and connected and torque converter shell by bolts, so the idler pulley with torque converter shell, is not rotating. Turbines and turbine hub with rivet riveted together, again by spline and turbine output shaft connection, turbine output shaft through the spline and the coupling connection, pass power to subsequent transmission system. Pump wheel rotate with the engine, the power input, idler pulley not rotating, turbine rotating, the power output, are independent of each other, among the clearance between wheel which is about 2 mm. Pump wheels, turbine, idler pulley itself is composed of many blade, called blade, blade consists of qu, in complex shapes. Torque converter at work, in the cascade is need full of oil, in high speed pump wheel rotates, the oil pump impeller blade under the action of centrifugal force along the curved flows, in the cascade exit into the turbine cascade exit, and then make the centripetal flow along the turbine blade surface, and export into roller blade is imported from turbine cascade, through the idler pulley cascade flow back to pump impeller. Pump wheels, turbine, roller blade is composed of a circular space, called a circular circle. Due to the design of the turbine blade surface shape, decided the turbine and pump wheel in the same direction. So, torque converter cascade cycle round the oil, on the one hand rotation in the circular circle, on the one hand, with the pump wheel and turbine rotation, thus formed the complex helical motion, in this kind of movement, pass the energy from the pump to the turbine. The load on the turbine is determined bulldozer load. Bulldozers load by the shovel is passed to the crawler walking system, and then to the final drive, steering clutch, the transmission, the transmission and coupling assembly, eventually passed on to the torque converter gas turbine. Turbine load hours, and its rotating speed is fast; High load, rotation speed is slow. When bulldozers walk because of overload, the turbine speed is reduced to 0, become a turbine braking state. At this time, due to the turbine stop running, the pump impeller blade to the oil, with the greatest impact through the turbine blade against the idler pulley, without turning roller blade is converted into pressure, the pressure to the turbine back pressure, increasing the turbine torque, the increase of torque and turbine rotate in the same direction, the turbine output torque is the largest, 2.54 times for pump wheel torque. Turbine increases as the load, speed to reduce gradually, torque increase gradually, the equivalent of a stepless transmission in slow down gradually increase torsion. This kind of stepless torque performance and easy to manipulate and block a less planetary gear type match the power shift transmission, make the bulldozer get excellent traction performance. Rely on hydraulic hydraulic torque converter works. Oil flow in the blade, due to the impact, friction, consumes energy, make the oil heat, so the transmission efficiency of hydraulic torque converter is lower. At present, the best efficiency of hydraulic torque converter has a top 88%. When the torque converter of the overload and stop rotating turbine for bulldozer, all by the energy of pump wheel was converted into heat and consume, and the torque converter efficiency is 0. To improve the transmission efficiency of torque converter, to master the bulldozer load, make the turbine has the appropriate speed, bulldozers have proper speed; As a bulldozer due to excessive load walk, to reduce the load in time, mention the shovel or by II cover for the I. By the structure and working principle of torque converter, the work of the torque converter oil will have inside leaking, get hot. This request in a timely manner to torque converter internal added oil, and will replace out of fever in oil is cooled, form a circle. TY320 and TY220 have completely similar hydraulic torque converter, only the geometrical amplification. TY160 type and TY220 Type a basic similar hydraulic torque converter, some structural changes. Their failure and maintenance is basically the same. 2, the planetary gear type power shift transmission This transmission is mainly composed of four planets and a rotating lockup clutch. Turn on the output of the planetary gear retarding mechanism. Is using II type TY220 bulldozer transmission planetary line used as reverse gear. The clutch has five. 1 to 4 clutch oil cylinder body are connected by a bolt on the end cover, they are not. When the oil is full of pressure oil between piston and cylinder, pressure oil in the oil more than plan, under the seal of oil pressure and push piston friction clamping piece, the ring gear can be fixed. Rotate the lockup clutch structure is special, it's not a planet, its work as a whole. Oil supply to the rotating cylinder, the need to be the first to central shaft oil supply. Work, pressure oil through 5 clutch stationary 19 in the shell oil, into the rotary cylinder, forces the pistons to work. To prevent leakage, with a rotating seal ring.Work out the oil, due to the rotating cylinder rolling, thrown outward centrifugal force, not the oil discharge, will increase the wear of friction plate. To solve this problem, in the rotating oil discharge, will increase the wear of friction plate. To solve this problem, on the oil cylinder to increase a ball check valve, under the action of pressure oil, its sealing oil hole on the establishment of a hydraulic, fuel cut-off, it will be off, open oil return hole in oil. TY220 bulldozer transmission, many characteristics in the structure, using these characteristics, can make the maintenance more easier. Such as 1 to 4 clutch friction plate and the CD is common; 2 to 4 rows of planets and piston ring is the same, same planet platoon guide pin of the clutch, separation disc spring is the same, separation of the clutch piston spring; 1 to 3 rows using the same planets; 4 rows of planets outside the frame using gear ring insert in the third planetary gear ring, and the spring retainer ring to prevent axial channeling move and so on. TY320 and TY220 bulldozer transmission series products have completely similar, only magnifies the geometry size. TY160 bulldozer transmission, clutch is arranged in a different way, clutch for forward gears 1, 2 clutch for back block, rotating lockup clutch I block 3, 4 clutch III block, 5 clutch for II. Ann has the same characteristics to use and repair. 3, steering clutch and brake Transmission power was introduced into the central transmission, from the vertical transmission into horizontal transmission, by the transverse respectively to the left and right two steering clutch. The steering clutch is the spring pressure, hydraulic pressure separation, constant mesh, temperature type lining structure. It consists of a drum, drum, pressure plate, external friction plate, inner gear, piston, bolt, the sleeve and the piston connection into a whole, small spring support, drum, push the piston to the right, the installation of spring load pressure clamp will friction piece and tooth piece tightly together, realize the joint force. 8 groups of spring, total installed load 3.2 T, enough pressure tight lining to transfer torque. When bulldozers need to turn left (such as pull to pull rod), huai pressure oil filling the steering clutch piston and wheel hub oil cavity between the oil pressure to push the pistons, drive pressure plate moving to the left, lining and tooth slice loosening, no longer transmission torque, bulldozers, lost power at the left, left shift driven on the right track. To end, loosen the tie rod, the hydraulic oil in the piston driven by circumfluence, steering clutch to joint force, bulldozers, back straight. TY220 bulldozer is steering brake hydraulic booster, floating wet-type brake belt type. It includes installed outside the steering clutch drum brake band, the power piston rod, connecting rod, connecting rod, float, etc. Due to the better performance of floating body, regardless of the clutch drum is forward or reverse, when the brake is very smooth, does not produce brake. When braking with the brake band on the 1.5 after 16 liner wear, brake band gap between and the outer drum, brake springboard stroke increases, when the stroke increases to a certain extent, brake unreliable. Therefore, to constantly adjust the brake band gap.