Repair and solution of qy8e central swivel joint o

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Repair and solution measures for qy8e central swivel joint of truck crane

after qy8e truck crane was idle for two years, there was external leakage in the adapter hair of the central loop. During the repair process, it was found that the groove depth of the 0-ring exceeded the allowable maximum depth by 0.1mm, resulting in insufficient initial compression of the 0-ring. In addition, the installation coaxiality of the shell and the core was out of tolerance and the 0-ring was aging, which did not play a sealing role, resulting in low-pressure leakage


when purchasing O-rings, deliberately choose products with larger inner diameter and section diameter in the same specification. Before assembly, carefully grind the opening of the joint shell and the groove of the core, remove burrs and apply grease to ensure that the 0-ring is not damaged during assembly. " He Minghui said that after the repair, no external leakage has occurred in the use of the central swivel

in order to improve the localization rate of materials in the civil aircraft industry, it is suggested that the manufacturer take the following measures in the design and processing:

(1) strictly control the dimensional tolerance and roughness of the groove part to ensure that the 0-ring has sufficient pre compression shrinkage and sufficient compression force between the 0-ring and the mating surface

(to achieve a win-win situation 2) strictly control the fit gap between the shell and the core to avoid the 0-ring being extruded and damaged

(3) strictly control the coaxiality between the sealing groove and the core to avoid seal failure caused by large compression of one part of the 0-ring, small compression of the other part or no compression at all

(4) carefully grind the hole of the joint shell and the groove of the core to remove burrs and prevent the 0-ring from being cut during assembly

(5) the 0-ring with large section is preferred in the design, or other oil seals are used

(6) add a stop valve at the outlet of the oil tank below the liquid level to facilitate repair


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