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1、<p> 本科生畢業(yè)設(shè)計(論文)外文翻譯</p><p> 畢業(yè)設(shè)計(論文)題目:幾種典型的制動器的對比分析與設(shè)計</p><p> 外文題目:A disc brake test stand for measurement of airborne wear particles</p><p> 譯文題目:盤式制動器試驗臺上測量空氣中磨損顆粒<
2、/p><p> 學(xué) 生 姓 名: </p><p> 專 業(yè): 車輛工程 </p><p> 指導(dǎo)教師姓名: </p><p> 評 閱 日 期:
3、 </p><p> A disc brake test stand for measurement of</p><p> airborne wear particles</p><p><b> ABSTRACT</b></p><p> During braking
4、, there is wear on both the rotor and the pads. This process generates particles that may become airborne. In fi eld tests, it is diffi cult to distinguish these particles from others in the surrounding environment.There
5、fore, a laboratory test stand has been designed which allows control of the cleanliness of the surrounding air. The test stand consists of a front right brake assembly mounted in a sealed chamber. A braking load is appli
6、ed by a pneumatic system and the rotor, which </p><p> braking loads. The results suggest that this test stand can be used to study rust layer removal from the rotor.</p><p> key words: wear;
7、airborne particles; disc brake; test stand; rust layer</p><p> INTRODUCTION</p><p> Many studies have shown an association between adverse health effects and the concentration of airborne part
8、icles in the atmosphere.1–3 In urban environments, airborne particles can come from different sources, e.g. demolition and construction,4 resuspended road dust,5 wheel-to-rail contact,6,7 car-to-road contact8,9 and disc
9、 brakes.10,11 During braking, both the brake pads and rotors are worn, generating wear particles. Some of these particles are deposited on the brake hardware, and others be</p><p> Furthermore, to ensure ro
10、bust brake performance, some brake systems may require the pads to frequently be in low pressure contact with the rotor. This dragging may remove any rust layer, which may build standing parked overnight in a wet environ
11、ment, from the rotor and keep the contact surfaces clean. However, the resulting drag torque increases the fuel consumption and generates wear particles, because the pads are still in contact with the rotor after the rus
12、t layer has been removed. It is the</p><p> When measuring airborne brake particles in fi eld tests, it can be diffi cult to distinguish them from other traffi c-generated aerosols. Therefore, it may be pre
13、ferable to use laboratory tests that allow control of the cleanliness of the surrounding air. Although several test stands have been built to study wear and friction at the pad-to-rotor interface, few studies12,13 have f
14、ocused on wear particles. In a laboratory test stand, the cleanliness of the surrounding air can be controlled, enabli</p><p> has been designed to measure the number and size of airborne wear particles gen
15、erated by disc brakes. The purpose of this paper was to describe this test stand and present the results of a fi rst test series to verify the experimental set-up. These tests focus on rust layer removal at low braking l
16、oads.</p><p> EXPERIMENTAL SET-UP</p><p> In this test stand, a front right brake assembly from a passenger car is used. The front right brake assembly consists of a knuckle, the wheel bearing
17、 and the disc brake assembly. The disc brake assembly in turn consists of a ventilated rotor, a sliding caliper with a single piston and two brake pads</p><p> (Figure 1). The fi nger side brake pad include
18、s a K-type thermocouple that measures the temperature near the fi nger side pad-to-rotor contact.A schematic diagram of the test stand is given in Figure 2. An electric direct current motor (K) with</p><p>
19、 a nominal torque of 191 Nm drives the rotor, and a pneumatic system (M) connected to the front right brake assembly (H) is used to apply a controlled braking load. When the brake is applied, the motor continues to drive
20、 the system at a stationary rotational speed, i.e. the test system throttles and brakes</p><p> at the same time. A drive shaft (L) transfers the torque from the motor to the wheel bearing, which in turn ro
21、tates the disc. The motor and the drive shaft are connected by a fi xed coupling, and the wheel bearing and the drive shaft are connected by a splined coupling. The knuckle is mounted to a suspension</p><p>
22、 device. A sealing chamber (G) seals the front right brake assembly from the surroundings. The electric motor is balanced with bearings on each end. The applied torque on the motor is measured using a calibrated strain
23、gauge force sensor multiplied by the distance from the motor centre,with an accuracy of ±2.2%. The rotational speed of the disc is measured by a built-in Hall effect sensor in the wheel bearing, with 48 pulses per r
24、evolution. A pneumatic system generates controlled low pressure lev</p><p> of ±0.5% by a calibrated piezoelectric pressure sensor near the inlet of the brake cylinder.</p><p> 盤式制動器試驗臺上測
25、量空氣中磨損顆粒</p><p><b> 摘要</b></p><p> 在制動過程中,制動盤和摩擦片都有磨損。這個過程產(chǎn)生的碎粒有可能進(jìn)入到空氣中。在實地測試中,是很難辨別來自周圍環(huán)境的其他碎粒的影響。因此,實驗室中試驗臺的設(shè)計,被允許對周圍空氣環(huán)境的清潔度進(jìn)行控制。該試驗臺中有一個右前方剎車總成,它安裝在一個密封腔中。制動負(fù)荷由氣壓系統(tǒng)實施,制動盤由電動馬達(dá)
26、驅(qū)動,制動盤表面已經(jīng)預(yù)先產(chǎn)生一層生銹層,用以模仿在潮濕的環(huán)境下停泊一晚的汽車的制動盤。然后測量空氣中的磨損顆粒的數(shù)量以及大小。這個實驗裝置已經(jīng)在低負(fù)荷制動下,經(jīng)過一系列的初始測試的結(jié)果所證實。這個結(jié)果表明該試驗臺能被用于研究制動盤生銹層除銹。</p><p> 關(guān)鍵詞:磨損;空氣中顆粒物;盤式制動器試驗臺;銹層</p><p><b> 簡介</b></p&
27、gt;<p> 許多研究已經(jīng)證明,對健康不利的影響和空氣中顆粒物在大氣中的濃度之間的關(guān)聯(lián)。在城市環(huán)境中,空氣中的顆粒物可能來自不同渠道,例如拆遷和建設(shè),粉塵懸浮路,輪軌到軌接觸,車到路面接觸以及盤式制動器。在制動過程中,無論是剎車片與制動盤的磨損,都會產(chǎn)生磨損顆粒。其中一些磨損顆粒沉積在制動系統(tǒng)的硬件上,而另一些則隨風(fēng)飄散。此外,為確??煽恐苿有阅?,一些制動系統(tǒng)需要剎車片與制動盤經(jīng)常處于低壓接觸狀態(tài)。這種牽引可以去除汽車
28、因在潮濕的環(huán)境停泊一晚所產(chǎn)生的任何生銹層,去除了制動盤上的銹層還能保持接觸面的清潔。然而,由此產(chǎn)生的阻力距增加了燃料的消耗和產(chǎn)生的磨損顆粒,因為摩擦片在生銹層去除后仍然會與制動盤接觸。因此,應(yīng)該在不影響剎車性能的前提下盡量減少剎車拖動。</p><p> 在實地測試時,測量空氣制動顆粒,區(qū)別它與其他方式產(chǎn)生的氣溶膠是很困難的。因此,允許控制周圍的空氣潔凈度可能是最好使用的實驗室測試。盡管有幾個試驗站已經(jīng)建成用于
29、研究耐磨以及制動盤和摩擦片界面摩擦,一些研究主要集中在磨損顆粒。</p><p> 在實驗室試驗臺,控制周圍的空氣潔凈度可以更多更準(zhǔn)確的研究空氣剎車磨損顆粒。考慮到這一點,實驗室組件試驗臺被設(shè)計來測量空氣中磨損顆粒的數(shù)量和盤式制動器磨損產(chǎn)生的顆粒大小。本文的目的是來描繪這個試驗臺和目前第一個測試系列的結(jié)果,用以驗證實驗裝置.這些實驗旨在研究低負(fù)荷制動下將如何去除生銹層。</p><p>
30、<b> 實驗裝置</b></p><p> 在這個測試站,使用到轎車右前制動總成。右前制動總成由轉(zhuǎn)向節(jié),車輪軸承和盤式制動器總成組成。盤式制動器總成又由一個通風(fēng)制動盤組成,它是指帶有活塞的浮鉗盤制動器和兩個摩擦片。手指端剎車片包括K型熱電偶,用來測量接近指端制動盤與摩擦片接觸面的溫度。</p><p> 該試驗臺的原理圖圖2中給出。電動直流馬達(dá)(k)與191牛
31、米的驅(qū)動器的轉(zhuǎn)子額定轉(zhuǎn)矩,和氣動系統(tǒng)(M)連接到右前方制動器總成(H)都是用來控制制動載荷應(yīng)用的。當(dāng)制動器工作時,電機(jī)始終推動系統(tǒng)處于一個固定的轉(zhuǎn)速,即測試系統(tǒng)油門和制動器在同一時間。傳動軸(L)將轉(zhuǎn)矩由電機(jī)傳遞到車輪軸承,進(jìn)而傳遞到制動盤上。電機(jī)和傳動軸由一個固定的耦合連接,車輪軸承和傳動軸由花鍵聯(lián)接。轉(zhuǎn)向節(jié)安裝在懸架裝置上。一個密封腔(G)將右前制動總成與周圍環(huán)境隔離。</p><p> 電動機(jī)靠兩端末的軸
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