Causes and Solutions for Repeated Damage to the Vibration-Damping Springs of Heavy-Duty Circular Vibrating Screens

The plant currently operates two 2YAC2460 ultra-heavy circular vibrating screens. Due to an increasingly heavy production workload over the past two years, the equipment's runtime has increased significantly. In 2003, the No. 2 vibrating screen experienced two incidents of severe distortion and twisting of its vibration-damping springs, where two adjacent springs became entangled in a helical interference pattern. This ultimately caused the screen box to tilt backward and drop down.

After analysis, two main causes were identified:

The upper and lower compression plates for the springs were not level.

The centerlines of the bolts connecting the upper and lower spring connection blocks were misaligned, causing the springs to be non-perpendicular to the compression plates and not parallel to each other.

Upon inspection, only the second issue was confirmed to be present. Measurements taken during operation verified that the upper compression plate had a bolt center distance of 258 mm, while the lower compression plate had a center distance of 290 mm. Since the diameter of each spring is 260 mm, it is evident that under such a configuration, spring interference and improper alignment are unavoidable. One spring will always be off vertical, resulting in uneven stress distribution between the two springs.

To resolve this issue, the only effective solution was to modify the center distance of the bolt holes on the upper compression plate to match that of the lower plate, i.e., 290 mm. The plant adopted a method involving overlay welding to fill the original holes on the upper plate, followed by grinding the surface smooth, accurately locating the new centers, and re-drilling the holes at the correct spacing.

After this modification, both springs were aligned perpendicular to the compression plates and maintained parallel positioning. Since the adjustment, no further spring failures have occurred.