[Mechanical Equipment Technology Edition] Daily Question 20181120: Analysis of Radial Runout in Matched Parts
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This post was last edited by B0SS on 2018-11-20 at 18:13. [Daily Question] An analysis of the principles behind alignment (everyone who comments on this post will receive 1-3 units of wealth as a reward; those who give a complete answer will receive 10-15 units, with the reward valid for two days). In a single-table setup where the table base is mounted on the motor coupling, and the dial indicator needle is pressed against the compressor’s coupling, when there are no issues with radial runout in either the vertical or horizontal direction, as well as no axial problems, this post discusses how to adjust for radial runout in the lateral direction. Let: the value read from the left table be a, and the value read from the right table be b, as shown in Figure 1 ； Left-right position deviation X, as shown in Figure 2. Action: The single gauge moves from the left to the right, rotating 180 degrees, as shown in Figure 1. At this point, we have a universal formula: as long as the value a in the table on the left moves towards (a+b)/2 ； Or, the value b in the right table can be adjusted towards (a+b)/2. Adjustment action: Adjust the front and rear bases of the motor, moving it left or right by X units, until the desired condition is achieved, that is, a=b (rotate 180 degrees as shown in Figure 1, so that a=b). It’s easy to understand – as long as a=b, the radial runout on the left and right sides is adjusted properly. To achieve a=b, it is sufficient that either a=(a+b)/2 or b=(a+b)/2. Can everyone derive this universal formula using the displacement deviation X? (Hint: First determine the relationship among a, b, and x) ； ) ============================== High-quality promotions: Mechanical equipment——Videos on the repair and adjustment of York compressors https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1806833 Mechanical equipment——Maintenance procedures for York screw compressors https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=1806833 Mechanical equipment——Upgrading of York Quinton control centers https://bbs.hcbbs.com/thread-1804837-1-1.html Mechanical equipment——Major repairs of GEA Grasox screw compressors https://bbs.hcbbs.com/thread-1800467-1-1.html Mechanical equipment——Disassembly and maintenance of British HOWDEN screw compressors https://bbs.hcbbs.com/thread-1832529-1-1.html Mechanical equipment——Disassembly and maintenance of Japanese Maekawa MYCOM screw compressors https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=
Assume a > b: then the compressor is offset to the left, and it needs to be moved to the right. If the movement distance is x, the compressor and the motor will be aligned vertically. At this point, the reading on the left gauge will be a – x, while the reading on the right gauge will be b + x. Since a – x = b + x, it follows that x = (a – b)/2. Clearly, the reading on the left gauge is a – x, which equals a – (a – b)/2 = (a + b)/2. Similarly, the reading on the right gauge is b + x, which also equals (a + b)/2. When a
I’m not quite sure what the universal formula is; the deviation value should be half the absolute value of A-B, I guess. We just make adjustments directly, without thinking about any universal formula.
The deviation value can be adjusted; specific numerical values can also be changed. When the deviation is large, it is recommended to use the deviation value for adjustment. The deviation can be reduced by making adjustments using specific values