Introduction to the tightening principle of the new 5911584-5 (Spiralock) nut 2010-09-06 Author: Zhao Heng Source: Hangcai.com Number of views: 765 User comments: 0
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When installing the IDG power feeder in the engine shop of the Overhaul Department of China Southern Airlines Shenyang Maintenance Base, a new type (Spiralock) with part number 5911584-5 was used ) Nut, the difference from ordinary nuts is that it can be easily screwed to the bottom of the terminal by hand, and it will form a self-locking torque after tightening. The manufacturer has a detailed introduction to the principle on the website, summarized here
When the engine workshop of the Overhaul Department of China Southern Airlines Shenyang Maintenance Base used a new (Spiralock) nut with the part number of 5911584-5 when installing the IDG power feeder , the difference from the ordinary nut is that it can be easily screwed to the bottom of the terminal by hand, and it will form a self-locking torque after tightening. The manufacturer has a detailed introduction to the principles on its website, and some of the content is summarized here for workers’ reference.
The general nut locking function relies on: adhesive, replacement bolts, anti-loosening washers, disk locks, fine teeth, safety nuts, fuses, cotter pins, locks, pre-tightening torque and Nylon rings, interference fits, etc., while the Spiralock nut relies on a special thread profile. Practice has proven that this nut is the only one to withstand the strong vibrations generated by the space shuttle rocket booster, and is currently the most ideal anti-tightening nut. solid method. The load distribution is reasonable and produces excellent loosening resistance.
Studies conducted by MIT's Lawrence Livermore National Laboratory and other researchers confirm that connections using Spiralock threads bear loads more evenly than other connections using standard 60° threads . Additionally, they noted that the load percentage on the first load-bearing thread tapped with a Spiralock tap was significantly smaller, at 24 versus 64 compared to the five load-bearing threads.
The uniform thread loading provided by Spiralock reduces the load concentrated on the first thread, thereby increasing the reliability of the connection by minimizing possible thread spalling. In addition, the Spiralock thread profile results in higher radial thread loads compared to standard threads, thereby utilizing the clamping strength of the material and reducing the potential for shear failure.
The unique 30° wedge-shaped ramp in the Spiralock thread profile contacts the external thread at a different angle than standard threads. The larger resultant force is redirected from axial to radial to create locking capability, so Spiralock threaded connections typically require 10 to 20 higher torque to create the same connection tension as a standard 60° threaded connection.
Although all Spiralock threaded connections require higher torque, the increase in torque required will depend on the type of material and coating used (nuts, bolts, mating surfaces, etc.). This torque/tension relationship should be calculated based on the actual joint to determine the appropriate torque required to produce the specified tension.
Additionally, testing has shown that Spiralock's uniform load distribution always reduces stress concentrations that lead to fatigue failure compared to standard fasteners, thereby extending fatigue life by more than 300.
I accidentally saw a report on the Internet. I hope it will be helpful to you. At the same time, I saw many fake spiralock products on the Internet. It is recommended to look for regular spiralock products. I hope it can help you.