Tham khảo tài liệu 'handbook of shaft alignment episode 3 part 2', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 600 Shaft Alignment Handbook Third Edition FIGURE Rim runout check on sheave. conditions as shown in the lower illustration in Figure . Adjustments to the machines may therefore require precise controlled moves in the vertical lateral and axial directions. USING A STRAIGHTEDGE TO MEASURE MISALIGNMENT Belt and sheave driven equipment poses a slightly different type of alignment problem than equipment directly coupled together. The basic objective is to insure that the shaft centerlines are parallel to each other. Aligning V-Belt Drives 601 FIGURE Face runout check on sheave. For decades the most widely used alignment tool is either a string or a straightedge. Today there are far more elaborate ways to perform belt-sheave alignment as shown later in this chapter but most often acceptable belt alignment can be accomplished using a simple straightedge. Bear in mind that most manufacturers of belt and sheave drives suggest that the sheaves should be aligned to within 1 8 in. per foot distance between shaft centerlines. That is about 11 mils in. much more forgiving that direct drive systems which are typically aligned to around 1 mil in. 602 Shaft Alignment Handbook Third Edition FIGURE Rim runout check on sheave. Straightedges work fine for distances under 4 ft but when the distance between the driver shaft and the driven shaft begin to exceed that a string should probably be used. One tool developed by Max Roeder called the A-String works extremely well and produces very accurate results shown in Figure and Figure . The A-String has an adjustable base that enables one to compensate for centerline offset of sheaves as shown in Figure . To properly align sheaves you must compensate for any difference in the actual center of the V in each sheave. Measure the width of the groove then measure the flange outer thickness on each sheave to determine what the offset may have to be if the outer flange widths are not the .
