Improper assembly: A contributing factor to disc spring failure

The assembly accuracy of disc springs in mechanical equipment serves as a critical factor determining their long-term reliability and operational performance. The quality of assembly directly impacts the overall stress distribution of disc springs during actual operation. Even minimal assembly deviations may cause abnormal stress distribution patterns, leading to issues such as uneven force distribution and localized overloads. These problems can ultimately result in premature failure or complete loss of functionality in disc springs.

1、Specific Impact of Neutral Bias and Case Analysis

During the assembly of disc springs, failure to achieve precise alignment—such as eccentricity, tilting, or misalignment with mating components—directly compromises their ideal axially symmetric stress distribution. Such deviations cause loads to concentrate unevenly across the spring's effective load-bearing surface, resulting in localized stress surges that far exceed material design limits. A case study involving a hydraulic control valve demonstrates how improper concentricity between the disc spring and mounting base during installation induced additional bending moments during service. This persistent abnormal stress state, exacerbated by prolonged cyclic loading, ultimately led to fatigue crack initiation and propagation at the spring's edge regions, culminating in edge fracture failure mode.

2、Accuracy and Critical Role of Preloading Control

The setting and control of preloading amount constitute a critical aspect in disc spring assembly, with its significance being undeniable. Excessive preloading subjects the disc spring to excessive initial stress, significantly compromising its ability to withstand subsequent alternating loads, thereby accelerating material fatigue damage and shortening service life. Conversely, insufficient preloading fails to provide adequate initial tension, potentially causing axial displacement or radial micro-motion during operation, resulting in unstable and uneven stress distribution. Moreover, if the actual compression stroke exceeds the designed tolerance range during installation or operation, the spring's working point may shift beyond the elastic deformation zone into the plastic deformation phase. This leads to permanent deformation, causing permanent loss of elastic recovery capability and load-bearing capacity.

3、Prevention and Control Measures for Wear During Assembly Process

During assembly, it is critical to ensure a tight and uniform contact between the disc spring's end face and the mounting base (or adjacent components). Loose fit, gaps, or uneven contact surfaces may cause partial load distribution, resulting in excessive localized contact stress and friction wear at micro-motion points that accelerate surface damage. Additionally, all impacts or scratches must be avoided during handling and assembly operations. Such mechanical surface defects—such as dents or scratches—serve as sharp stress concentration points. Under cyclic loading conditions, these defects can readily trigger micro-crack initiation and propagation, ultimately leading to fatigue failure.

For detailed assembly process specifications tailored to specific applications or professional on-site assembly technical guidance, please contact Sunzo's business service team through official channels for further details and support.