現(xiàn)代汽車發(fā)動機(jī)前端附件傳動輪系日趨復(fù)雜。輪系設(shè)計(jì)直接影響整車的工作可靠性，因此受到世界各大汽車公司的高度重視。傳統(tǒng)的發(fā)動機(jī)附件傳動輪系一直采用V帶傳動，但由于其彎曲性能較差，已無法滿足現(xiàn)代汽車在較小空間內(nèi)傳動多個(gè)附件的要求。多楔帶集平帶的高柔韌性和V帶的高功 率性于一體，不僅可用一條帶傳動多個(gè)附件，而且能雙面使用，例如采用背部張緊裝置，使許多原來用V帶傳動的設(shè)計(jì)困難迎刃而解。多楔帶的應(yīng)用為發(fā)動機(jī)前端附 件傳動輪系設(shè)計(jì)開辟了新的途徑。目前歐美國家發(fā)動機(jī)前端附件傳動輪系已基本全部采用多楔帶；日本基于可靠性考慮，多采用一條多楔帶與V帶并用形式。
但是，由于現(xiàn)代汽車發(fā)動機(jī)空間越來越小，帶傳的部件多和功率大，而使用多楔帶多為單根帶傳多個(gè)部件，因此對多楔帶的性能要求非常的高，一般要求能在
汽車多楔帶是汽車發(fā)動機(jī)重要的零部件，也是傳動帶重要的組成部分?？梢哉f，傳動帶的許多技術(shù)進(jìn)步和發(fā)明與汽車工業(yè)的發(fā)展息息相關(guān)，如V帶發(fā)明，切邊V帶、多楔帶和同步帶的快速發(fā)展，氫化丁腈橡膠（HNBR）在同步帶應(yīng)用、三元乙丙橡膠（EPDM）在多楔帶應(yīng)用等，都是為了適應(yīng)汽車工業(yè)最新技術(shù)要求而獲得迅速發(fā)展的。汽車多楔帶發(fā)展趨勢主要往高性能、長壽命、節(jié)能、高精度、低排放和低噪音及集成化模塊式等方向發(fā)展。
近年來，由于全球氣候變暖、環(huán)境保護(hù)和對汽車舒適性要求，節(jié)能、排放和NVH（噪音、振動和平穩(wěn)）是汽車工業(yè)主要話題。如何提高燃料利用率和減少廢氣排放、提高維修周期一直是汽車工業(yè)研究目標(biāo)，這些技術(shù)包括多閥門（Multivalve Engines，MVES）和變閥門（Variable Valve Timing ，VVT）技術(shù)[1]、催化轉(zhuǎn)換器、42V發(fā)電/啟動集成電機(jī)（integrated starter alternator，ISA）[2]、直噴式柴油發(fā)動機(jī)和240 000 Km甚至300 000 Km維修周期[3]等。這些技術(shù)進(jìn)步對汽車零部件的性能要求也相應(yīng)提高和苛刻，汽車傳動帶也不例外。為了適應(yīng)這些變化，國外一些著名傳動帶廠家對汽車多楔帶進(jìn)行了許多改進(jìn)和性能提高。
1．彈性多楔帶
彈性多楔帶最早用于白色家電如洗衣機(jī)、干洗機(jī)和健身器材等。原理是，帶的長度比輪系計(jì)算周長小，帶在裝配時(shí)，使用專用工具強(qiáng)制拉伸在固定的帶輪上，通過帶的彈性變形力使帶產(chǎn)生足夠的張力。在整個(gè)使用過程中無需調(diào)整張力，這樣可以省略張力調(diào)節(jié)機(jī)構(gòu)。近幾年來，小型家用轎車為了簡化發(fā)動機(jī)前端附件傳動輪系結(jié)構(gòu)也開始使用彈性多楔帶作為驅(qū)動用帶。彈性多楔帶一般使用扯斷伸長率大于20%的高捻度的尼龍纖維作為強(qiáng)力層線繩。
2．齒形多楔帶
齒形多楔帶類似于齒形切邊V帶，即在楔部切成齒形，以提高帶的曲撓性能及帶散熱性能，可明顯提高帶使用壽命。固特異公司研究表明，相同的氯丁橡膠（CR）材料多楔帶，高溫疲勞試驗(yàn)普通多楔帶66h，有齒多楔帶可達(dá)167h[5]。有齒多楔帶還可降低對帶的裝配精度要求。但有齒多楔帶在使用時(shí)通過帶輪會帶進(jìn)帶出空氣流，產(chǎn)生有節(jié)奏的氣流聲。固特異公司通過斜齒，DAYCO公司做成不規(guī)則齒來抵消這種聲音，可減少15dB左右的噪音。兩家公司分別以 “Gatorhark”和“POLY COG”標(biāo)識推向市場。
3．EPDM多楔帶
近年來，多楔帶在汽車得到普遍應(yīng)用，而發(fā)動機(jī)室的溫度越來越高，有的要求橡膠件能耐150℃，瞬間能耐170℃，傳統(tǒng)氯丁橡膠（CR）顯然達(dá)不到要求。由于HNBR過于昂貴，人們在研究發(fā)現(xiàn)小量的油污并不對發(fā)動機(jī)前端的皮帶造成損害[9]，可使用較廉價(jià)耐熱性好多的三元乙丙橡膠（EPDM）作為多楔帶主體橡膠材料。但EPDM耐磨性、高溫抗撕裂和動態(tài)性能不理想，與其它材料粘合差，這些都需要通過改性如添加ZDA或ZDMA和與其它材料并用加以解決。
EPDM多楔帶耐高溫性能和高溫疲勞壽命明顯提高，如CR多楔帶
4．植絨多楔帶
多楔帶傳動缺點(diǎn)之一是傳動噪音較大，在低速或角速度變化快使用時(shí)，以及一段時(shí)間后，楔面磨損、硬化和張力松弛，或在雨天沾到水后，傳動時(shí)會發(fā)出刺耳的尖叫聲，影響汽車的NVH性能。解決辦法之一是楔面留有0.1～1.0mm高強(qiáng)度短纖維（如芳綸、PBO纖維等）由于纖維摩擦系數(shù)穩(wěn)定、具有吸音功能，因此大大降低多楔帶傳動噪音，植絨多楔帶一般用特殊的研磨工藝來實(shí)現(xiàn)。研磨時(shí)，先將楔快速磨成大致的楔形，然后低速濕磨，將橡膠磨掉，楔面露出一定長度的纖維。Ribbed status quo with the latest technological developments
The increasing complexity of modern automotive engine front-end accessory drive wheel. The gear train design a direct impact on vehicle reliability, and therefore attach great importance to the world's major car companies. The conventional engine accessory drive gear train has been using the V-belt transmission, but because of its poor bending properties, has been unable to meet the requirements of the modern cars in less space drive multiple attachments. Ribbed set the high flexibility of flat belts and V-band high-power, not only can be used a belt drive multiple attachments, and using both sides, for example, using the back of the tensioning device, so that many of the original with V-belt transmission design difficulties solved. The Ribbed application engine front-end accessory drive wheel is designed to open up a new way. Europe and the United States the engine front end accessory drive gear train has been basically used in all V-ribbed belts; Japan based on reliability considerations, the use of a V-ribbed belts and V-belts and use forms.
However, due to the modern automobile engine space is getting smaller and smaller, with the transfer of parts and power of large, use Ribbed single band pass multiple components require very high and therefore the performance of the V-ribbed belts, the general requirements In the high temperature of 120 ℃ life of more than 100 000km. Traditional CR material has been unable to meet the requirements of the current multi-use of HNBR. 110 ° C and 130 ° C, the fatigue life for the HNBR Ribbed different CR Ribbed contrast to a [3], we can see the the HNBR Ribbed fatigue life is much higher than the CR Ribbed, especially In the high temperature conditions.
Automotive Ribbed important parts of an automobile engine, belt an important part of. It can be said that the belt of technological progress and invention of the automobile industry is closely related to the development, such as the V-belt invention, cutting edge V-belt, the rapid development of the V-ribbed belts and timing belts, hydrogenated nitrile rubber (HNBR) in the timing belt, three yuan ethylene propylene rubber (EPDM) Ribbed applications are in order to adapt the requirements of the automotive industry the latest technology and rapid development. Automotive Ribbed development trends to develop in the direction of high-performance, long life, energy saving, high-precision, low emissions and low noise and the integrated module type.
In recent years, due to global warming, environmental protection and the car's comfort requirements, energy efficiency, emissions and NVH (noise, vibration and smooth) is the automotive industry the main topic. How to improve fuel efficiency and reduce emissions, improve the maintenance cycle has been in the automotive industry research objectives, these technologies include multi-valve (Multivalve of Engines, MVES) and variable valve (Variable Valve Timing VVT) technology [1], catalytic converter , 42V power generation / boot integrated motor (integrated starter alternator, ISA) [2], direct injection diesel engine and 240 000 in the Km and even 300 000 the Km maintenance cycle [3]. These technical advances auto parts performance requirements have been increased and harsh, automotive belt is no exception. In order to adapt to these changes, some foreign famous belt manufacturers vehicle Ribbed many improvements and performance improvements.
A. Flexibility Ribbed
Elastic Ribbed earliest for white goods such as washing machines, dry cleaning machines and fitness equipment and so on. The principle is that, with the length of the gear system to calculate the circumference of a small belt assembly, using a dedicated tool to force the stretch in the fixed pulley deformation by the elastic band force with enough tension. No need to adjust the tension in the entire process, so you can omit the tension adjusting mechanism. In recent years, a small family car in order to simplify the structure of the engine front end accessory drive gear train flexibility Ribbed as a driver to use with. Elastic Ribbed general tensile elongation greater than 20% high-twist nylon fiber layer as a strong cord.
Two. Tooth Ribbed
Tooth the Ribbed similar to the tooth edged V belt, namely the Ministry of the wedge cut into the tooth, in order to improve the flex band and with heat dissipation, and can significantly increase the belt life. Goodyear study shows that the same material chloroprene rubber (CR), ribbed belt, high temperature fatigue test common Ribbed 66h, V-ribbed belts have teeth up to 167h [5]. Toothed V-ribbed belts can reduce the belt assembly precision requirements. However, tooth V-ribbed belts in use through the pulley into the belt out of the air stream, resulting in the rhythmic sound of the airflow. Goodyear through the helical gear, DAYCO company made up of irregular teeth to offset the sound can be reduced about 15dB of noise. The two companies were "Gatorhark" and "POLY the COG logo to market.
3. EPDM ribbed belts
In recent years, ribbed belts widely used in the automotive and engine room temperature is getting higher and higher, and some require the rubber pieces capability of 150 ° C, the instant capability of 170 ° C, apparently fail to meet requirements of the traditional chloroprene rubber (CR). HNBR is too expensive, the study found that a small amount of oil does not cause damage to the engine front-end of the belt [9], you can use cheaper heat resistance, a lot of ethylene propylene diene monomer rubber (EPDM) as a V-ribbed belts the main rubber material. EPDM wear resistance, high temperature and tear and dynamic performance is not satisfactory, and poor adhesion with other materials, which are by modification such as adding ZDA or ZDMA, and other materials and to solve them.
