1、资 料 及 译 文译文题目： A magnetorheological clutch for efficient automotive auxiliary device actuation 磁流变离合器的高效汽车辅助设备驱动 学生姓名： 学号： 专业： 所在学院： 指导教师： 职称： 20xx年 02 月 25 日 英语原文A magnetorheological clutch for efficient automotive auxiliary device actuationABSTRACT .In this paper the results of a project funded by
2、 Regione Toscana aimed at reducing the power absorption of auxiliary devices in vehicles are presented. In particular the design, testing and application of a magnetorheological clutch (MR) is proposed, aimed at disengaging the vacuum pump, which draws in air from the power-brake booster chamber, in
3、 order to reduce the device power absorption.Several clutch preliminary studies done to choose the clutch geometry and the magnetic field supply are illustrated. The final choice consisted in an MR clutch with permanent magnet, which satisfied size, torque and fail-safe specifications. The clutch ch
4、aracteristics, in terms of torque versus slip, were obtained experimentally for three different clutch prototypes on an ad-hoc developed test bench.As result of a preliminary simulation, a comparison between the power absorption of a current production vacuum pump, an innovative vacuum pump and both
5、 vacuum pumps coupled with the MR clutch is presented. The New European Driving Cycle is considered for simulating the vacuum pump operation both in urban and highway driving. Results show that the use of the innovative vacuum pump reduces the device consumption of about 35%, whereas the use of MR c
6、lutch coupled with the innovative vacuum pump reduces it up to about 44% in urban driving and 50% in highway driving.KEYWORDS. Magnetorheological fluid; Magnetorheological clutch; Permanent magnet; Test bench, Experimental testing; Automotive; NEDC.INTRODUCTIONNowadays, the reduction of consumption
7、and emissions represents, together with safety and comfort issues, some of the leading trends for vehicle development. Fuel saving is promoted by the increasing attention devoted to environment protection and, at the same time, it is enforced by the pressing regulations on emissions (e.g. current EU
8、RO 5 and future EURO 6 emission standards).The reduction of consumption and emissions is pursued by different strategies, which involve several research fields. The most radical approach deals with the design and implementation of innovative drive-train technologies, such as hybrid applications for
9、the short to medium term period, or the use of different fuels (e.g. hydrogen, ammonia, bio-fuels etc.) or different energy supply-chain (pure electric vehicles) for the long term period. However, these solutions often present a long time-to-market and, in some cases, collide with energy processing
10、and storage .Another research field deals with the enhancement of transportation efficiency; current trends aim at reducing the consumptions and emissions by enforcing public transportation or encouraging private vehicles sharing.At the same time the main OEMs component suppliers and research instit
11、utes have been studying several particular solutions aimed at reducing the incidence of auxiliary device absorption (e.g. oil, water and vacuum pumps, air conditioning system etc.), improving the component efficiency (e.g. bearing resistance, seal friction etc.) and reducing the component mass. In p
12、articular, the reduction in consumptions is actually analysed with reference to the NEDC driving cycle, which takes into account several driving cycles including engine warm-up.The reduction of oil pump absorptions has been recently studied in by controlling the oil pressure as a function of the eng
13、ine speed and engine temperature. Other studies focus on the control of variable displacement pumps on the basis of the engine oil request. In a switchable water pump was designed in order to disconnect the auxiliary device from the engine when the engine temperature results lower than a threshold v
14、alue.Multiphysics research also led to the use of smart materials in vehicle performance optimization. In 9 and 10 the engine cooling fan is driven by a controllable magnetorheological clutch. The use of smart materials permits the regulation of speed and, consequently, of power absorbed by the cool
15、ing fan optimizing its operation on the basis of temperature control (e.g. the cooling fan could be disengaged during engine warm-up). The use of smart materials in the automotive industry has been pursued since many years, especially in suspension design , in order to improve the drivers comfort and the vehicle dynamic performance by changing the apparent viscosity of the MR fluid filling the dampers.In this paper a multiphysics research aimed at reducing the absorption of vacuum pumps in Diesel engines is presented. The activity was carried out in co-operation betwe
