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1.旋转轴的失调及其基本形式所谓旋转轴的失调,是指驱动机器的转轴与从动机器的转轴不在同一中心线上,图1a和1b显示了旋转轴失调的两种基本形式:水平和角度.在实际场合的问题中,旋转轴的失调,通常是这两种形式在水平和垂直方向的组合,如图1c所示.旋转轴的失调以水平偏距(x毫英寸)或斜度(x/L:毫英寸/英寸)来测量.在驱动和从动转轴间的完美校准几乎是不可能达到的.即使可达到初始的完美校准,由于各种因素也不可能维持相当一段时间,这些因素有诸如轴承套上产生的热量,润滑系统,气体压缩和基座移动.实际中,一些残余的失调经常还存留在驱动和从动的转轴间.所以,由转轴的失调引起的能量损失是相当明显的,因为在实际场合有大量的旋转机器,转轴的失调通常由振动测量和分析来进行诊断.然而,最近的研究表明,失调的结果有时并不在振动图谱上表现出来.某些情形下,由转轴失调产生的扰动力频率与系统的任何固有频率并不接近,因而不能明显地激活系统.因此,除了振动测量外,在正常运转条件下,经常性地校准检查以保证转轴准直是十分重要的.
1. Rotary shaft misalignment and its basic form The so-called spin-axis imbalance, refers to the drive shaft and the driven machine’s shaft is not on the same center line, Figure 1a and 1b show two basic forms of rotation shaft disorders: level And angle. In real-world problems, the misalignment of the rotating shaft is usually a combination of both forms in horizontal and vertical as shown in Figure 1c. The misalignments of the rotating shaft occur at a horizontal offset (x milli-inch) or oblique Degrees (x / L: milli-inch / inch). Perfect alignment between the driven and driven spindles is almost impossible to achieve. Even though the initial perfect alignment can be achieved, it can not be maintained for a considerable period of time due to various factors These factors include, for example, the heat generated in the bearing housing, the lubrication system, the gas compression and the pedestal movement. In practice, some residual offsets often remain between the driven and driven shafts, so the energy caused by the misalignment of the shaft Losses are quite obvious because there are a large number of rotating machines on a real-world occasion where off-axis rotations are usually diagnosed by vibration measurement and analysis.However, recent studies have shown that the effects of offsets are sometimes not reflected in the vibrational profiles In some cases, the disturbance frequency generated by the misalignment of the shaft is not close to any natural frequency of the system and therefore does not significantly activate the system. Therefore, in addition to the vibration measurement, under normal operating conditions, the calibration check To ensure that the shaft alignment is very important.