2404 沖壓廢料自動(dòng)輸送裝置設(shè)計(jì)
2404 沖壓廢料自動(dòng)輸送裝置設(shè)計(jì),沖壓,廢料,廢物,自動(dòng),輸送,裝置,設(shè)計(jì)
附件 3：邵陽(yáng)學(xué)院畢業(yè)設(shè)計(jì)（論文）任務(wù)書(shū)年級(jí)專(zhuān)業(yè) 2004 級(jí)機(jī)制專(zhuān)科專(zhuān)業(yè) 學(xué)生姓名 尹婷 學(xué) 號(hào) 0430817055課題名稱(chēng) 沖 壓 廢 料 自 動(dòng) 輸 送 裝 置 設(shè) 計(jì)設(shè)計(jì)(論文)起止時(shí)間 2007 年 3 月 20 日至 2007 年 6 月 9 日課題類(lèi)型 工程設(shè)計(jì) 課題性質(zhì) 真實(shí)一、課題設(shè)計(jì)（研究）的目的和主要內(nèi)容研究目的：綜合機(jī)械制造專(zhuān)業(yè)所學(xué)課程的理論和實(shí)踐知識(shí)，進(jìn)行一次實(shí)際解決問(wèn)題的設(shè)計(jì)，培養(yǎng)學(xué)生獨(dú)立解決設(shè)計(jì)和制造上理論與實(shí)際問(wèn)題的能力, 提高學(xué)生資料查閱和靈活使用軟件語(yǔ)言的能力。完成工廠沖壓廢料自動(dòng)輸送裝置的設(shè)計(jì)。主要內(nèi)容：設(shè)計(jì)出一臺(tái)適應(yīng)不同模具尺寸的沖壓廢料自動(dòng)輸送裝置，使用一臺(tái)馬達(dá)同時(shí)驅(qū)動(dòng)多條輸送帶，解決了一臺(tái)馬達(dá)驅(qū)動(dòng)一條輸送帶所帶來(lái)的橫向空間不夠的問(wèn)題。使廢料收集更方便、安全。提高生產(chǎn)效率。二、基本要求1、必須獨(dú)立完成畢業(yè)設(shè)計(jì)工作。2、完成裝備圖、主要部件圖、重要的零件圖、皮帶運(yùn)輸機(jī)的電氣原理圖。3、按學(xué)院畢業(yè)設(shè)計(jì)的書(shū)寫(xiě)格式要求，撰寫(xiě)設(shè)計(jì)說(shuō)明書(shū)，畢業(yè)設(shè)計(jì)說(shuō)明書(shū)不少于 30000 字。4、應(yīng)完成 3000-5000 個(gè)文字的與畢業(yè)設(shè)計(jì)有關(guān)的外文資料翻譯, 譯文要求準(zhǔn)確,文字流暢。注：1、此表由指導(dǎo)教師填寫(xiě)，經(jīng)各系、教研室主任審批，指導(dǎo)教師、學(xué)生簽字后生效；2、此表 1 式 3 份，學(xué)生、指導(dǎo)教師、教研室各 1 份。三、課題研究已具備的條件（包括實(shí)驗(yàn)室、主要儀器設(shè)備、參考資料）1、實(shí)習(xí)工廠沖壓設(shè)備。2、邵陽(yáng)學(xué)院圖書(shū)館相關(guān)資料：如主要參考資料：《沖壓設(shè)備》 ， 《機(jī)械設(shè)計(jì)手冊(cè)》 ， 《機(jī)械設(shè)計(jì)》， 《機(jī)床電氣控制原理》, 期刊雜志《模具工業(yè)》 、 《沖壓技術(shù)》 、 《沖壓工藝》 、中國(guó)沖壓件網(wǎng)、沖壓廢料處理網(wǎng)。3、課題前期的調(diào)查、研究工作四、設(shè)計(jì)（論文）進(jìn)度安排2 月 20 日～3 月 20 日：調(diào)研、資料準(zhǔn)備、確定方案、繪制草圖；3 月 21 日～4 月 21 日：完成裝配圖、部件圖、零件圖；4 月 22 日～5 月 22 日：編寫(xiě)設(shè)計(jì)說(shuō)明書(shū)；5 月 23 日～6 月 10 日：校對(duì)、總結(jié)、準(zhǔn)備答辯。五、教研室審批意見(jiàn)教研室主任（簽字） 年 月 日六、系審批意見(jiàn)系主任（簽字） 單位（公章） 年 月 日指導(dǎo)教師（簽字）： 學(xué)生（簽字）：邵 陽(yáng) 學(xué) 院畢業(yè)設(shè)計(jì)（論文）開(kāi)題報(bào)告書(shū)課 題 名 稱(chēng) 沖壓廢料自動(dòng)輸送裝置 學(xué) 生 姓 名 尹 婷 學(xué) 號(hào) 0430817055 系 、 專(zhuān) 業(yè) 機(jī) 械 與 能 源 工 程 系 機(jī) 械 制 造 工 藝 與 設(shè) 備 指 導(dǎo) 教 師 陳 志 剛 2007 年 3 月 20 日一、課題的來(lái)源、目的意義（包括應(yīng)用前景） 、國(guó)內(nèi)外現(xiàn)狀及水平課題來(lái)源：目前還有很多工廠的沖壓廢料清除方式都是最原始的人工清掃，機(jī)箱裝載。手工生產(chǎn)線需停機(jī)清掃，自動(dòng)生產(chǎn)線雖不停機(jī)，但清掃時(shí)極不安全。同時(shí)手工清掃廢料及目前廢料收集方式使整個(gè)生產(chǎn)現(xiàn)場(chǎng)顯得零亂。廢料滿地散落，場(chǎng)地不清潔，人工清除廢料勢(shì)必停機(jī)作業(yè)，影響生產(chǎn)效率。目的：通過(guò)綜合運(yùn)用所學(xué)的知識(shí)，在老師的指導(dǎo)下解決實(shí)際工程問(wèn)題，培養(yǎng)學(xué)生理論聯(lián)系實(shí)際的能力，良好的設(shè)計(jì)思想和工作作風(fēng)。意義：本次設(shè)計(jì)是要求解決實(shí)際的工程問(wèn)題，不僅要求掌握具有相當(dāng)?shù)膶?zhuān)業(yè)知識(shí)，還可以鍛煉獨(dú)立解決問(wèn)題的能力，提高查閱設(shè)計(jì)手冊(cè)的能力，熟悉相關(guān)的國(guó)家標(biāo)準(zhǔn)的國(guó)際標(biāo)準(zhǔn)，更加熟練操作繪圖軟件繪制工程圖。最重要的是能讓我們學(xué)到的理論知識(shí)運(yùn)用到實(shí)踐中，提高實(shí)踐能力。使我們的設(shè)計(jì)更具實(shí)用性，能為社會(huì)發(fā)展貢獻(xiàn)自己的一份微薄之力。本次設(shè)計(jì)還能讓我們更多的接觸社會(huì)，了解社會(huì)的發(fā)展態(tài)勢(shì)和國(guó)內(nèi)外的研究現(xiàn)狀，為自己以后的發(fā)展奠定基礎(chǔ)。應(yīng)用前景：本課題就針對(duì)模具墊腳高度、間距及位置不一，夾模器的干涉，如何從模下自動(dòng)清除廢料等問(wèn)題，設(shè)計(jì)一種適應(yīng)性強(qiáng)，效率高，安全可靠的廢料自動(dòng)輸送裝置。應(yīng)用相當(dāng)?shù)膹V泛。國(guó)內(nèi)外現(xiàn)狀及水平：在沖壓作業(yè)中，沖壓機(jī)械設(shè)備、模具、作業(yè)方式對(duì)安全影響很大。實(shí)現(xiàn)沖壓機(jī)械化和廢料收集自動(dòng)化，能大幅度提高沖壓設(shè)備的利用率和勞動(dòng)生產(chǎn)率并保證人身安全。但是，沖壓作業(yè)的動(dòng)作頻率高，又多數(shù)是薄板加工，所以保證沖壓機(jī)械化和廢料收集自動(dòng)化的可靠性在技術(shù)上實(shí)現(xiàn)的難度較大。沖壓廢料的收集常常需要停機(jī)工作，既影響生產(chǎn)，又極不安全。目前，國(guó)內(nèi)、外研究的輸送裝置往往只針對(duì)一種沖壓產(chǎn)品，當(dāng)遇到模具墊腳高度、間距及位置不一，夾模器的干涉等問(wèn)題時(shí)， ，從模下自動(dòng)清除廢料非常困難，本課題著重解決以上問(wèn)題，設(shè)計(jì)制造完成以后，將在國(guó)內(nèi)得到廣泛地應(yīng)用。二、課題研究的主要內(nèi)容、研究方法或工程技術(shù)方案和準(zhǔn)備采取的措施課題研究的主要內(nèi)容：沖壓廢料自動(dòng)輸送裝置的設(shè)計(jì)，包括：設(shè)計(jì)出一臺(tái)適應(yīng)不同模具尺寸的沖壓廢料自動(dòng)輸送裝置，使用一臺(tái)馬達(dá)同時(shí)驅(qū)動(dòng)多條輸送帶，解決了一臺(tái)馬達(dá)驅(qū)動(dòng)一條輸送帶所帶來(lái)的橫向空間不夠的問(wèn)題。使廢料收集更方便、安全。提高生產(chǎn)效率。工程技術(shù)方案和準(zhǔn)備采取的措施：1、使用一臺(tái)馬達(dá)同時(shí)驅(qū)動(dòng)多條輸送帶，解決了一臺(tái)馬達(dá)驅(qū)動(dòng)一條輸送帶所帶來(lái)的橫向空間不夠的問(wèn)題；2、輸送帶橫向位置可任意調(diào)整，以適應(yīng)不同的墊腳位置。3、一種輸送帶寬度可適應(yīng)一定范圍的墊腳間距，輸送帶可任意組合，以適應(yīng)不同的模具尺寸。4、換模時(shí)可方便地移動(dòng)輸送帶，且各皮帶整體及單位皮帶伸入模具下的深度可調(diào)，適應(yīng)不同的模具尺寸。5、換線時(shí)，可方便地更換輸送帶。6、超薄皮帶可越過(guò)夾模器或壓板地阻擋，更好地利用空間。7、本次設(shè)計(jì)全面滿足用戶要求的各項(xiàng)標(biāo)準(zhǔn)、規(guī)范要求，同時(shí)參考國(guó)際標(biāo)準(zhǔn)，對(duì)產(chǎn)品進(jìn)行全面的優(yōu)化設(shè)計(jì)。三、現(xiàn)有基礎(chǔ)和具備的條件通過(guò)大學(xué)四年的學(xué)習(xí)，本人已經(jīng)掌握了基本的專(zhuān)業(yè)知識(shí)，對(duì)本課題的相關(guān)學(xué)科有一定的了解，具有了相關(guān)的理論基礎(chǔ)。學(xué)校還組織進(jìn)行了各種課程設(shè)計(jì)，積累了一定的經(jīng)驗(yàn)，對(duì)本次設(shè)計(jì)將會(huì)有很大的幫助。學(xué)校提供了大量的相關(guān)資料、技術(shù)支持以及實(shí)驗(yàn)設(shè)備和實(shí)驗(yàn)場(chǎng)地。學(xué)院圖書(shū)館收藏了許多有關(guān)專(zhuān)業(yè)方面的知識(shí)書(shū)籍和周刊，并且提供了網(wǎng)絡(luò)化的機(jī)房，可以在中國(guó)期刊網(wǎng)、維普網(wǎng)、萬(wàn)方數(shù)據(jù)庫(kù)、超星數(shù)字圖書(shū)館等網(wǎng)站查閱有關(guān)資料。對(duì)目前工廠的各種沖壓設(shè)備的廢料輸送的調(diào)查及論證，一些非自動(dòng)的沖壓廢料輸送裝置的運(yùn)用，運(yùn)輸機(jī)械的調(diào)研和在實(shí)際中的應(yīng)用?，F(xiàn)具有的一些參考資料如：（1） 、 《機(jī)械設(shè)計(jì)手冊(cè)》（2） 、 《鏈傳動(dòng)》（3） 、 《連續(xù)運(yùn)輸機(jī)》（4） 、 《機(jī)械設(shè)計(jì)》（5） 、 《沖壓設(shè)備》（6） 、 《輸送機(jī)設(shè)計(jì)手冊(cè)》（7） 、 《電工技術(shù)》（8） 、 《機(jī)床電氣控制原理》除了以上的資料，還有沖壓機(jī)自動(dòng)輸送裝置的一些圖樣及其相關(guān)的資料、AUTOCAD 繪圖軟件、OFFICE 辦公軟件等。四、總的工作任務(wù)，進(jìn)度安排以及預(yù)期結(jié)果總的工作任務(wù)：總裝配圖的繪制和主要零件圖的繪制；說(shuō)明書(shū)的編寫(xiě)（２～３萬(wàn)字） ；翻譯相關(guān)英文資料 1 篇。進(jìn)度安排：2 月 20 日～3 月 20 日：調(diào)研、資料準(zhǔn)備、確定方案、繪制草圖3 月 21 日～4 月 21 日：完成裝備圖、部件圖、零件圖4 月 22 日～5 月 22 日：編寫(xiě)設(shè)計(jì)說(shuō)明書(shū)5 月 23 日～6 月 10 日：校對(duì)、總結(jié)、準(zhǔn)備答辯預(yù)期結(jié)果：完成 1 篇相關(guān)英文資料的翻譯。完成對(duì)輸送機(jī)的結(jié)構(gòu)和功能分析，確定總體方案設(shè)計(jì)，并繪制出裝配圖。完成電動(dòng)機(jī)、輸送裝置設(shè)計(jì)計(jì)算和零部件圖的繪制，撰寫(xiě)詳細(xì)的設(shè)計(jì)說(shuō)明書(shū)。我希望能提前完成任務(wù)，并且把錯(cuò)誤降低到最低點(diǎn)，使本設(shè)計(jì)具有相當(dāng)?shù)膶?shí)用性。五、指導(dǎo)教師審查意見(jiàn)指導(dǎo)教師（簽名） 年 月 日 六、教研室審查意見(jiàn)教研室主任（簽名） 年 月 日 七、院（系）審查意見(jiàn)院（系）主任（簽名） 年 月 日 備 注1A Comparison of Soft Start Mechanisms for Mining Belt ConveyorsMichael L. Nave, P.E.CONSOL Inc.1800 Washington Road Pittsburgh, PA 15241 Belt Conveyors are an important method for transportation of bulk materials in the mining industry. The control of the application of the starting torque from the belt drive system to the belt fabric affects the performance, life cost, and reliability of the conveyor. This paper examines applications of each starting method within the coal mining industry.INTRODUCTIONThe force required to move a belt conveyor must be transmitted by the drive pulley via friction between the drive pulley and the belt fabric. In order to transmit power there must be a difference in the belt tension as it approaches and leaves the drive pulley. These conditions are true for steady state running, starting, and stopping. Traditionally, belt designs are based on static calculations of running forces. Since starting and stopping are not examined in detail, safety factors are applied to static loadings (Harrison, 1987). This paper will primarily address the starting or acceleration duty of the conveyor. The belt designer must control starting acceleration to prevent excessive tension in the belt fabric and forces in the belt drive system (Suttees, 1986). High acceleration forces can adversely affect the belt fabric, belt splices, drive pulleys, idler pulleys, shafts, bearings, speed reducers, and couplings. Uncontrolled acceleration forces can cause belt conveyor system performance problems with vertical curves, excessive belt take-up movement, loss of drive pulley friction, spillage of materials, and festooning of the belt fabric. The belt designer is confronted with two problems, The belt drive system must produce a minimum torque powerful enough to start the conveyor, and controlled such that the acceleration forces are within safe limits. Smooth starting of the conveyor can be accomplished by the use of drive torque control equipment, either mechanical or electrical, or a 2combination of the two (CEM, 1979).SOFT START MECHANISM EVALUATION CRITERIONWhat is the best belt conveyor drive system? The answer depends on many variables. The best system is one that provides acceptable control for starting, running, and stopping at a reasonable cost and with high reliability (Lewdly and Sugarcane, 1978). Belt Drive System For the purposes of this paper we will assume that belt conveyors are almost always driven by electrical prime movers (Goodyear Tire and Rubber, 1982). The belt "drive system" shall consist of multiple components including the electrical prime mover, the electrical motor starter with control system, the motor coupling, the speed reducer, the low speed coupling, the belt drive pulley, and the pulley brake or hold back (Cur, 1986). It is important that the belt designer examine the applicability of each system component to the particular application. For the purpose of this paper, we will assume that all drive system components are located in the fresh air, non-permissible, areas of the mine, or in non-hazardous, National Electrical Code, Article 500 explosion-proof, areas of the surface of the mine.Belt Drive Component Attributes Size.Certain drive components are available and practical in different size ranges. For this discussion, we will assume that belt drive systems range from fractional horsepower to multiples of thousands of horsepower. Small drive systems are often below 50 horsepower. Medium systems range from 50 to 1000 horsepower. Large systems can be considered above 1000 horsepower. Division of sizes into these groups is entirely arbitrary. Care must be taken to resist the temptation to over motor or under motor a belt flight to enhance standardization. An over motored drive results in poor efficiency and the potential for high torques, while an under motored drive could result in destructive overspending on regeneration, or overheating with shortened motor life (Lords, et al., 1978).Torque Control. Belt designers try to limit the starting torque to no more than 150% of 3the running torque (CEMA, 1979; Goodyear, 1982). The limit on the applied starting torque is often the limit of rating of the belt carcass, belt splice, pulley lagging, or shaft deflections. On larger belts and belts with optimized sized components, torque limits of 110% through 125% are common (Elberton, 1986). In addition to a torque limit, the belt starter may be required to limit torque increments that would stretch belting and cause traveling waves. An ideal starting control system would apply a pretension torque to the belt at rest up to the point of breakaway, or movement of the entire belt, then a torque equal to the movement requirements of the belt with load plus a constant torque to accelerate the inertia of the system components from rest to final running speed. This would minimize system transient forces and belt stretch (Shultz, 1992). Different drive systems exhibit varying ability to control the application of torques to the belt at rest and at different speeds. Also, the conveyor itself exhibits two extremes of loading. An empty belt normally presents the smallest required torque for breakaway and acceleration, while a fully loaded belt presents the highest required torque. A mining drive system must be capable of scaling the applied torque from a 2/1 ratio for a horizontal simple belt arrangement, to a 10/1 ranges for an inclined or complex belt profile.Thermal Rating. During starting and running, each drive system may dissipate waste heat. The waste heat may be liberated in the electrical motor, the electrical controls,, the couplings, the speed reducer, or the belt braking system. The thermal load of each start Is dependent on the amount of belt load and the duration of the start. The designer must fulfill the application requirements for repeated starts after running the conveyor at full load. Typical mining belt starting duties vary from 3 to 10 starts per hour equally spaced, or 2 to 4 starts in succession. Repeated starting may require the dreading or over sizing of system components. There is a direct relationship between thermal rating for repeated starts and costs. Variable Speed. Some belt drive systems are suitable for controlling the starting torque and speed, but only run at constant speed. 4Some belt applications would require a drive system capable of running for extended periods at less than full speed. This is useful when the drive load must be shared with other drives, the belt is used as a process feeder for rate control of the conveyed material, the belt speed is optimized for the haulage rate, the belt is used at slower speeds to transport men or materials, or the belt is run a slow inspection or inching speed for maintenance purposes (Hager, 1991). The variable speed belt drive will require a control system based on some algorithm to regulate operating speed. Regeneration or Overhauling Load. Some belt profiles present the potential for overhauling loads where the belt system supplies energy to the drive system. Not all drive systems have the ability to accept regenerated energy from the load. Some drives can accept energy from the load and return it to the power line for use by other loads. Other drives accept energy from the load and dissipate it into designated dynamic or mechanical braking elements. Some belt profiles switch from motoring to regeneration during operation. Can the drive system accept regenerated energy of a certain magnitude for the application? Does the drive system have to control or modulate the amount of retarding force during overhauling? Does the overhauling occur when running and starting? Maintenance and Supporting Systems. Each drive system will require periodic preventative maintenance. Replaceable items would include motor brushes, bearings, brake pads, dissipation resistors, oils, and cooling water. If the drive system is conservatively engineered and operated, the lower stress on consumables will result in lower maintenance costs. Some drives require supporting systems such as circulating oil for lubrication, cooling air or water, environmental dust filtering, or computer instrumentation. The maintenance of the supporting systems can affect the reliability of the drive system.Cost. The drive designer will examine the cost of each drive system. The total cost is the sum of the first capital cost to acquire the drive, the cost to install and commission the drive, the cost to operate the drive, and the cost to maintain the drive. The cost for power to operate the drive may vary widely 5with different locations. The designer strives to meet all system performance requirements at lowest total cost. Often more than one drive system may satisfy all system performance criterions at competitive costs.Complexity. The preferred drive arrangement is the simplest, such as a single motor driving through a single head pulley. However, mechanical, economic, and functional requirements often necessitate the use of complex drives. The belt designer must balance the need for sophistication against the problems that accompany complex systems. Complex systems require additional design engineering for successful deployment. An often-overlooked cost in a complex system is the cost of training onsite personnel, or the cost of downtime as a result of insufficient training.SOFT START DRIVE CONTROL LOGICEach drive system will require a control system to regulate the starting mechanism. The most common type of control used on smaller to medium sized drives with simple profiles is termed "Open Loop Acceleration Control". In open loop, the control system is previously configured to sequence the starting mechanism in a prescribed manner, usually based on time. In open loop control, drive-operating parameters such as current, torque, or speed do not influence sequence operation. This method presumes that the control designer has adequately modeled drive system performance on the conveyor. For larger or more complex belts, "Closed Loop" or "Feedback" control may he utilized. In closed loop control, during starting, the control system monitors via sensors drive operating parameters such as current level of the motor, speed of the belt, or force on the belt, and modifies the starting sequence to control, limit, or optimize one or wore parameters. Closed loop control systems modify the starting applied force between an empty and fully loaded conveyor. The constants in the mathematical model related to the measured variable versus the system drive response are termed the tuning constants. These constants must be properly adjusted for successful application to each conveyor. The most common schemes for closed loop 6control of conveyor starts are tachometer feedback for speed control and load cell force or drive force feedback for torque control. On some complex systems, It is desirable to have the closed loop control system adjust itself for various encountered conveyor conditions. This is termed "Adaptive Control". These extremes can involve vast variations in loadings, temperature of the belting, location of the loading on the profile, or multiple drive options on the conveyor. There are three common adaptive methods. The first involves decisions made before the start, or 'Restart Conditioning'. If the control system could know that the belt is empty, it would reduce initial force and lengthen the application of acceleration force to full speed. If the belt is loaded, the control system would apply pretension forces under stall for less time and supply sufficient torque to adequately accelerate the belt in a timely manner. Since the belt only became loaded during previous running by loading the drive, the average drive current can be sampled when running and retained in a first-in-first-out buffer memory that reflects the belt conveyance time. Then at shutdown the FIFO average may be use4 to precondition some open loop and closed loop set points for the next start. The second method involves decisions that are based on drive observations that occur during initial starting or "Motion Proving'. This usually involves a comparison In time of the drive current or force versus the belt speed. if the drive current or force required early in the sequence is low and motion is initiated, the belt must be unloaded. If the drive current or force required is high and motion is slow in starting, the conveyor must be loaded. This decision can be divided in zones and used to modify the middle and finish of the start sequence control. The third method involves a comparison of the belt speed versus time for this start against historical limits of belt acceleration, or 'Acceleration Envelope Monitoring'. At start, the belt speed is measured versus time. This is compared with two limiting belt speed curves that are retained in control system memory. The first curve profiles the empty belt when accelerated, and the second one the fully loaded belt. Thus, if the current speed versus time is lower than the loaded profile, it may indicate that the belt is overloaded, 7impeded, or drive malfunction. If the current speed versus time is higher than the empty profile, it may indicate a broken belt, coupling, or drive malfunction. In either case, the current start is aborted and an alarm issued.CONCLUSIONThe best belt starting system is one that provides acceptable performance under all belt load Conditions at a reasonable cost with high reliability. No one starting system meets all needs. The belt designer must define the starting system attributes that are required for each belt. In general, the AC induction motor with full voltage starting is confined to small belts with simple profiles. The AC induction motor with reduced voltage SCR starting is the base case mining starter for underground belts from small to medium sizes. With recent improvements, the AC motor with fixed fill fluid couplings is the base case for medium to large conveyors with simple profiles. The Wound Rotor Induction Motor drive is the traditional choice for medium to large belts with repeated starting duty or complex profiles that require precise torque control. The DC motor drive, Variable Fill Hydrokinetic drive, and the Variable Mechanical Transmission drive compete for application on belts with extreme profiles or variable speed at running requirements. The choice is dependent on location environment, competitive price, operating energy losses, speed response, and user familiarity. AC Variable Frequency drive and Brush less DC applications are limited to small to medium sized belts that require precise speed control due to higher present costs and complexity. However, with continuing competitive and technical improvements, the use of synthesized waveform electronic drives will expand.
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