Tham khảo tài liệu 'handbook of shaft alignment part 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 220 Shaft Alignment Handbook Third Edition methods will show you how to find the positions of two shaft centerlines when the machinery is not running step 5 in Chapter 1 . Once you have determined the relative positions of each shaft in a two-element drive train the next step is to determine if the machinery is within acceptable alignment tolerances Chapter 9 . If the tolerance is not yet acceptable the machinery positions will have to be altered as discussed in Chapter 8 which discusses a very useful and powerful technique where the data collected from these methods Chapter 10 through Chapter 15 can be used to construct a visual model of the relative shaft positions to assist you in determining which way and how far you should move the machinery to correct the misalignment condition and eventually achieve acceptable alignment tolerances. DIMENSIONAL MEASUREMENT The task of accurately measuring distance was one of the first problems encountered by man. The job of rope stretcher in ancient Egypt was a highly regarded profession and dimensional measurement technicians today can be seen using laser interferometers capable of measuring distances down to the submicron level. It is important for us to understand how all of these measurement tools work since new tools rarely replace old ones and they just augment. Despite the introduction of laser shaft alignment measurement systems in the early 1980s for example virtually all manufacturers of these systems still include a standard tape measure for the task of measuring the distances between the hold down bolts on machinery casings and where the measurement points are captured on the shafts. The two common measurement systems in worldwide use today are the English and metric systems. Without going into a lengthy dissertation of English to metric conversions the easiest one most people can remember is this mm in. By simply moving the decimal point three places to the left it becomes obvious that mm .
