共查询到20条相似文献,搜索用时 93 毫秒
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旋转式空调压缩机的振动和噪声研究 总被引:1,自引:0,他引:1
介绍了压缩机振动和噪声测试的基本原理和系统组成,分析了空调压缩机的结构和受力,查明了引起振动和噪声的根本原因,并揭示了空调压缩机在运行状态改变的条件下,振动和噪声的变化规律。 相似文献
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将电梯振动系统看成两个单自由度子系统的组成,求解子系统振动的激励频率和固有频率,这是分析电梯振动较为传统的方法。现从多自由度系统的角度,提出较为全面的电梯振动模型,并求出模型固有频率的计算公式;分别用这两种方法通过实例求解系统固有频率,并作比较。 相似文献
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行星式插入振动律适用于各种混凝土工程施工,它对于塑性、半塑性、干硬性、半干硬性,有钢筋或无钢筋的混凝土振捣都能使用。正因其有如此好的适应性,振动棒的使用几乎覆盖了整个建筑业,因此对振动律的设计也就显得越来越重要了。回激振原理软轮行星式插入振动棒,它是由可更换的振动棒、软轴、防逆装置和电动机等组成。电动机安装在支座上,便于在现场浇注放置或移动。行星式振动律的构造如图所示,振动棒是工作部件,它的外壳是一个圆柱型的空心铜筒。由棒头1与棒壳体3两段组成,两者通过螺纹连接成一体,上部端头车有内螺纹,工作时与… 相似文献
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介绍了笔者开发出的数控振动攻丝机床控制系统组成的结构,本系统可以实现的三大功能和振动攻丝软件的设计思路及实现方法。 相似文献
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电磁振动机械设备的发展与展望 总被引:1,自引:0,他引:1
概述了电磁学发展过程以及振动学的发展过程,介绍了振动设备的组成并且对各种振动设备进行了比较。电磁学和振动学的发展推动了电磁振动机械设备的产生和发展。介绍了电磁激振器的组成和原理,对电磁振动技术的应用和发展进行了展望。 相似文献
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振动轮是振动压路机的重要部件,其主要功能是通过振动作用压实地基,平整路面。YZ14G压路机振动轮主要由振动轮体、轴承座、偏心轴和中间轴等组成,具有结构简单、装配精度高等特点。振动轮体结构如图1所示,要求两端大孔轴线对基准轴线A-B的同轴度为φ0.08mm。若同轴度值超差较大,将影响中间轴花键的联接与配合,进而引起轴承旋转不畅、发热、磨损,还可能导致振动轮体的撕裂,造成严重后果。 相似文献
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将转子分为若干段,化成由若干个子系统组成的振动系统,推导出了子系统机械导纳合成的计算公式,根据这些公式即可对子系统进行综合,求出振动系统总的机械导纳。计算各频率下系统的机械导纳值,画出导纳一频率曲线,根据曲线的峰值点,即可得到振动系统的固有频率及转子的临界转速 相似文献
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降低发动机扭转振动的方法之一是加装曲轴扭转减振器。而传统的纯橡胶阻尼式曲轴扭转减振器由于其橡胶材料的滞后角普遍较小,因此不能在较宽的频域范围内提供适当的阻尼,导致其减振、隔振的效果较差。介绍了硅油-橡胶复合阻尼式扭转减振器的结构,建立了该扭转减振器的力学模型并提出了基于粒子群优化方法的设计参数优化方法。计算结果表明,优化后的系统中曲轴的扭转振动幅值降低,并通过实验验证了硅油-橡胶复合阻尼式扭转减振器控制发动机曲轴扭转振动的有效性。 相似文献
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Torsional vibration of flexible drive chain is a historical issue. With the maximization development and the rotating machinery high-speed operation, the drive chain systems of large-scaled units become more and more complex, which makes the torsional vibration problems becoming increasingly prominent in recent years. This article deeply analyzed the small signal stability of large-scaled WECS based on CMT, elaborated the torsional vibration mechanism and reasons for the first time and pointed out torsional vibration is caused by the disturbance wind and the DPC strategy. The disturbance wind is an external stimulus and can produce a low-frequency torsional vibration at the same frequency as wind speed. The DPC could weaken the drive chain damping. If the total damping of drive chain is negative, the unstable torsion vibration will occur. And if the drive chain is still a under-damped dynamic, the high-frequency torsional vibration at natural frequency will be generated. Therefore, large-scaled WECS must have damping control. This study found that appropriate enhancing drive chain stiffness could reduce low-frequency torsional vibration caused by wind speed. Therefore, a damping and stiffness compensation control method was proposed to suppress the torsional vibration. Compared with the conventional damping control, the new method not only can suppress the high-frequency torsional vibration but also has a good restraining effect on the low-frequency torsional vibration. Furthermore, the detailed design procedures including the calculation of injection damping and stiffness were given in this paper. Finally, the correctness and effectiveness of our analysis were further verified by the simulation experiments 相似文献
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针对曲轴扭转振动与整机辐射噪声问题,以某直列四缸发动机曲轴系统为研究对象,基于AVL Excite软件,在匹配扭振减振器(torsional vibration damper,TVD)与不匹配TVD两种情况下,采用弹性流体动力学模型轴承计算模型研究了曲轴扭振对机体所受激励与轴瓦表面压力分布的影响;并且在两种情况下,分别对曲轴扭振与车内噪声进行了试验测试,测试与主观评价表明,匹配TVD情况下曲轴扭振幅值降低,车内原有异响声明显改善。研究分析结果表明,扭振会使得曲轴模态频率附近范围内机体所受激励幅值增加,改变轴瓦表面载荷的幅值与分布规律,导致发动机乃至整车产生异响。 相似文献
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Experiment on the characteristics of torsional vibration of rotor-to-stator rub in turbomachinery 总被引:1,自引:0,他引:1
By use of the DK-II torsional vibration measuring system, the characteristics of torsional vibration of a rotor with rotor-to-stator rub are studied. It can be concluded that the measured natural torsional frequency (frub) with rub is higher than the one (fori) without rub. When rub happens, if the rotating frequency is higher than frub, torsional vibrations with a measured natural torsional frequency (frub) and 1×, 2× are excited; if the rotating frequency is between frub and fori, the torsional vibration which is so called resonance (one-time rotating frequency) is excited; if the rotating frequency is lower than fori, torsional vibrations with one-time rotating frequency and frub are excited, and a small torsional vibration with 2× is excited too. 相似文献