【正文】 本科畢業(yè)設(shè)計 外文文獻(xiàn) 及 譯文 文獻(xiàn)、資料題目： Belt conveying systems and driving system 文獻(xiàn)、資料來源： 期刊 文獻(xiàn)、資料發(fā)表（出版）日期： 院 （部）： 機(jī)電 工程學(xué)院 專 業(yè)： 機(jī)械電子 班 級： 姓 名： 學(xué) 號： 指導(dǎo)教師： 翻譯日期： 山東建筑大學(xué)畢業(yè)設(shè)計外文文獻(xiàn)及譯文 1 外文 文獻(xiàn) ： Belt conveying systems and driving system Among the methods of material conveying employed， belt conveyors play a very important part in the reliable carrying of material over long distances at petitive cost。 Conveyor systems have bee larger and more plex and drive systems have also been going through a process of evolution and will continue to do so。 Nowadays， bigger belts require more power and have brought the need for larger individual drives as well as multiple drives such as 3 drives of 750 kW for one belt(this is the case for the conveyor drives in Chengzhuang Mine)。 The ability to control drive acceleration torque is critical to belt conveyors’ performance。 An efficient drive system should be able to provide smooth， soft starts while maintaining belt tensions within the specified safe limits。 For load sharing on multiple drives， torque and speed control are also important considerations in the drive system’s design。 Due to the advances in conveyor drive control technology， at present many more reliable。 Costeffective and performancedriven conveyor drive systems covering a wide range of power are available for customers’ choices。 1 Analysis on conveyor drive technologies 1． 1 Direct drives Fullvoltage starters 。 With a fullvoltage starter design， the conveyor head shaft is directcoupled to the motor through the gear drive。 Direct fullvoltage starters are adequate for relatively lowpower, simpleprofile conveyors。 With direct fullvoltage starters， no control is provided for various conveyor loads and depending on the ratio between full and noload power requirements， empty starting times can be three or four times faster than full load。 The maintenancefree starting system is simple， lowcost and very reliable。 However, they cannot control starting torque and maximum stall torque； therefore， they are limited to the lowpower, simpleprofile conveyor belt drives． Reducedvoltage starters。 As conveyor power requirements increase， controlling the applied motor torque during the acceleration period bees increasingly important。 Because motor torque 1second a function of voltage， motor voltage must be controlled。 This can be achieved through reducedvoltage starters by employing a silicon controlled rectifier(SCR)。 A mon starting method with SCR reducedvoltage starters is to apply low voltage initially to take up 山東建筑大學(xué)畢業(yè)設(shè)計外文文獻(xiàn)及譯文 2 conveyor belt slack， and then to apply a timed linear ramp up to full voltage and belt speed。However, this starting method will not produce constant conveyor belt acceleration。 When acceleration is plete， the SCRs, which control the applied voltage to the electric motor， are locked in full conduction, providing fullline voltage to the motor。 Motors with higher torque and pull—up torque， can provide better starting torque when bined with the SCR starters, which are available in sizes up to 750 KW． Wound rotor induction motors。 Wound rotor induction motors are con