外文翻譯--皮帶傳送系統(tǒng)及其牽引系統(tǒng)-wenkub
2023-05-19 06:11:25 本頁(yè)面
【正文】 trol systems are custom designed to meet a conveyor system’s particular specifications。 As the conveyor accelerates， the resistance is reduced slowly to maintain a constant acceleration torque。 Wound rotor induction motors are connected directly to the drive system reducer and are a modified configuration of a standard AC induction motor。 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(jì)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, they cannot control starting torque and maximum stall torque； therefore， they are limited to the lowpower, simpleprofile conveyor belt drives． Reducedvoltage starters。 With a fullvoltage starter design， the conveyor head shaft is directcoupled to the motor through the gear drive。 For load sharing on multiple drives， torque and speed control are also important considerations in the drive system’s design。 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)。 Due to the advances in conveyor drive control technology， at present many more reliable。 Direct fullvoltage starters are adequate for relatively lowpower, simpleprofile conveyors。 As conveyor power requirements increase， controlling the applied motor torque during the acceleration period bees increasingly important。However, this starting method will not produce constant conveyor belt acceleration。 By inserting resistance in series with the motor’s rotor windings。 On multipledrive systems， an external slip resistor may be left in series with the rotor windings to aid in load sharing。 Wound rotor motors are appropriate for systems requiring more than 400 kW 。 The DC drive system is mechanically simple, but can include plex customdesigned electronics to monitor and control the plete system。 1． 2 Hydrokiic coupling 山東建筑大學(xué)畢業(yè)設(shè)計(jì)外文文獻(xiàn)及譯文 3 Hydrokiic couplings， monly referred to as fluid couplings， are posed of three basic elements。 The power produced by this coupling is based on the circulated fluid’s amount and density and the torque in proportion to input speed。 this normally is between l% and 3%． Basic hydrokiic couplings are available in configurations from fractional to several thousand kW 。 Variablefill drain couplings。 The coupling’s rotating casing contains bleedoff orifices that continually allow fluid to exit the working circuit into a separate hydraulic reservoir。 The drives can be mechanically plex and depending on the control parameters。 The scoop control fluid coupling consists of the three standard fluid coupling ponents： a driven impeller, a driving runner and a casing that encloses the working circuit。 This control provides reasonably smooth acceleration rates。 lower dv/dt per switching for each of the devices， and superior harmonic quality at the output。 2． 1 Power section To meet the demands for medium voltage applicati
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