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系统采用FPGA设计了步进电机正弦脉宽调制细分驱动电路,提高了步进电机的步进分辨率,并设计了功率驱动电路,对细分电路输出信号进行了隔离和功率放大,以确保电机能够稳定可靠地运行。经过对二相混合式步进电机测试表明,步进电机运行平稳,定位精度较高,改善了步进电机的运行性能,适用于要求较高的实时控制系统。 相似文献
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作为燃料电池汽车系统重要设备之一,空气压缩机必须具备压缩空气完全无油的条件。为此,本文提出了一种采用同步控制实现双电机驱动的无油螺杆压缩机,并对其展开了试验研究。结果表明:双驱动无油螺杆压缩机的伺服控制系统实现了主从电机较为理想的跟随误差,主电机的稳态误差为0.011°,从电机的稳态误差为0.013°,在压缩机负载不超过电机额定功率下,压缩机阴阳转子啮合误差不超过67.19μm,转速和排气背压对双驱动压缩机同步性能有着显著影响。因此,采用双驱动控制的无油螺杆压缩机设计方案切实可行,但在设计中应重点考虑排气背压和转子啮合间隙的设计,特别是转子间隙应从同步控制精度和压缩机性能2个角度进行综合考虑。 相似文献
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基于单片机的混凝土压力试验机用数控阀设计 总被引:1,自引:1,他引:0
提出一种混凝土压力试验机专用的数控液压阀,利用阀芯的线性运动设计阀结构,控制器以单片机为核心,压力反馈信号与设定值进行差值运算后得出控制信号,采用步进电机作为阀芯驱动元件,实现了直接数字控制.该阀具有较高的的控制精度和响应频率,成本低,可靠性和灵活性好. 相似文献
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提出一种混凝土压力试验机专用的数控液压阀,利用阀芯的线性运动设计阀结构,控制器以单片机为核心,压力反馈信号与设定值进行差值运算后得出控制信号,采用步进电机作为阀芯驱动元件,实现了直接数字控制。该阀具有较高的的控制精度和响应频率,成本低,可靠性和灵活性好。 相似文献
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压缩机的步进电机控制 总被引:1,自引:0,他引:1
提出了用步进电机控制压缩机系统压力的方法,设计了步进电机驱动电路以及数字式调节器,该步进电机控制系统可提高压缩机系统的控制精度、可靠性和压缩机寿命。 相似文献
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某钢厂轧机支撑辊采用油膜轴承结构,并用稀油润滑,针对原设计中存在的油压不稳、经常出现压力罐油液冲顶或排空从而造成系统进气或压力罐失去作用等问题,对4300mm宽厚板轧机油膜轴承润滑系统进行了改造。将手动阀门改为电控通断阀,由PLC系统自动检测压力罐的油位和气压,自动实现调整。经优化应用表明,系统运行稳定。 相似文献
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2D伺服阀采用伺服螺旋机构实现阀芯的角位移转换为阀芯的轴向位移。采用2D阀的结构方案实现了1000 L/min大流量阀的设计。采用步进电机作为电 机械转换器,并采用位置和电流闭环来驱动阀芯转动。为了实现步进电机输出角位移连续可控采用了步进电机连续跟踪算法的控制方法并在步进控制中引入脉宽调制控制技术,并以此为基础搭建了试验平台,设计了以TMS320F2812作为CPU的2D伺服阀控制器。在分析该阀的结构和工作原理基础上,对该阀频率响应进行实验研究。实验表明:该阀具有良好的动态特性,在幅值为25%阀满开口的正弦信号输入下,相位滞后90°对应的频宽约为50 Hz 。 相似文献
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根据结晶器振动以重力为主以交变惯性力为辅的负载特性,步进液压缸采用单出头大速比液压 油缸,有杆腔直接供高压、无杆腔压力伺服调节,三通伺服阀控制的技术方案.通过步进电机驱动滚珠丝杠旋转并带动螺母和伺服阀阀芯上下直线运动,步进液压缸的活塞轴跟随伺服阀阀芯上下运动. 相似文献
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为研究不同提取方法对锂基润滑脂中基础油提取效果的影响,采用12-羟基硬脂酸体系稠化基础油制备锂基润滑脂,然后采用石油醚提取法和压力分油提取法分别提取制备的润滑脂中的基础油,并分析2种不同方法提取的基础油与原稠化基础油在黏度、族组成、低温性能和组分构成方面的差别。结果表明:2种不同方法提取的基础油的红外谱图与稠化基础油的红外谱图基本一致,族组成和苯胺点也与稠化基础油基本一致;压力分油提取法提取的基础油的黏度、黏指、倾点和蒸发损失与稠化基础油一致;石油醚提取法提取的基础油的黏度与混合基础油中的小黏度基础油基本一致,黏指和倾点与润滑脂稠度相关,蒸发损失略大于原稠化基础油。对于润滑脂的剖析,2种方法结合使用可以得出较为准确的结果。 相似文献
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The effect of temperature on grease flow properties in pipes was investigated using both theoretical and experimental methods. A theoretical model for pipe flow was obtained by using the Herschel-Bulkley (H-B) rheology model. The H-B parameters at different temperatures were obtained from flow curves measured on a rheometer. The flow properties in the pipes were studied and combined with the theoretical model and H-B parameters. In addition, pressure drop experiments were carried out to verify the theoretical model. The model can be used to predict the critical temperature at which a lubrication system would no longer be able to deliver a sufficient grease flow rate. 相似文献
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采用BVT-1型轴承振动测量仪分别评价了含微米聚四氟乙烯和纳米二氧化硅的脲基脂的噪声性能,用四球实验机测试了这两种脲基脂的摩擦磨损行为,利用扫描电子显微镜观察了钢球的磨斑表面形貌。结果表明:微米聚四氟乙烯和纳米二氧化硅对脲基脂的噪声的低频和中频特性影响小,对高频特性影响大,但变化规律复杂。当微米聚四氟乙烯和纳米SiO2的质量分数分别为1%时,测试轴承的声音较均匀,低频和中频的速度值均达到最小值,且2种脲基脂都具有较好的摩擦性能。在这2种脲基脂润滑下,钢球的主要磨损特征均为黏着磨损。 相似文献
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Total vegetable oil greases are those in which both the lubricant and gellant are formed from vegetable oil. Vegetable oil may be used as a lubricant as such or, with appropriate structural modification, as an ester or alkylated ester. Total vegetable oil greases have the advantage of good biodegradability and conform to the requirements for high performance. Total vegetable‐oil based greases can be formed by mixing preformed soap and lubricant in the required proportions to form a grease with the desired properties. Alternatively, a grease can be formed from the same vegetable oil by simultaneous alcoholysis and saponification of the oil to form the lubricant and soap. The alkali used as a catalyst for the alcoholysis reaction serves as a reactant for the saponification reaction. The use of the appropriate proportion of oil, alcohol, and alkali will thus form a grease of the desired composition. A simultaneous reaction scheme to form sodium and lithium grease using castor oil has been studied. The alcoholysis reaction is separately studied for its kinetics, and the kinetics of the alcoholysis and saponification reaction are reported. Greases with 20% soap have been formed and their properties evaluated. 相似文献
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为提高复合铝基润滑脂的综合性能,采用矿物油(KN4010)为基础油,以12-羟基硬脂酸、硬脂酸、苯甲酸、氢氧化锂、异丙醇铝为稠化剂原料,制备一系列复合铝-锂基润滑脂。通过对其滴点、锥入度、钢网分油与摩擦因数等重要参数的表征,研究基础油含量与铝锂比例对复合铝-锂基润滑脂性能的影响。结果表明:铝锂比例为3∶1时制备的复合铝-锂基润滑脂具有较高的滴点、极低的钢网分油量与较低的蒸发损失,同时摩擦因数与磨斑直径均明显低于复合铝基润滑脂。复合铝-锂基润滑脂中Al、Li元素可能在减磨过程中起到共同作用,从而使摩擦因数与磨斑直径均明显低于复合铝基润滑脂。 相似文献
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Three kinds of ionic liquids (1‐butyl‐3‐methylimidazolium hexafluorophosphate (L‐P104), 1‐hexyl‐3‐methyl imidazolium hexafluorophosphate (L‐P106) and 1‐octyl‐3‐methylimidazolium tetrafluoroborate (LB108)) were added to the attapulgite base grease and the bentone base grease to investigate and compare the tribological behaviours of the ionic liquids with the two base greases at room temperature and 150°C. Tribological tests were performed using a ball‐on‐plate reciprocating tribometer. The attapulgite base grease showed better wear resistance properties than that of bentone base grease by adding ionic liquids as additives. At same time, the attapulgite base grease showed excellent friction‐reducing and wear resistance properties at high temperature (150°C). Also, we discussed the tribological mechanism of the attapulgite base grease at both room temperature and 150°C from the aspect of the structure of the grease thicker. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献