All springs experience a loss of load or relaxation in the course of time, which is primarily dependent on the occurring stress and the temperature-time curve.

For disc springs the stress distribution in the cross-section also plays a role determined by the dimensional relationships δ and h_o/t. The relaxation can therefore be related to stress µ_OM, because it best reflects all other influences. Depending on the installation situation, the load loss may occur as creeping or relaxation. Creeping is described as a loss of length Δl which the spring suffers under a constant load F, and relaxation as a loss in load Δ F if the spring is installed at a constant length l.

Approximate values for the permissible relaxation of disc springs under static loads are provided in figure 29 and 30.

If working temperatures above 100^oC occur, we recommend you contact us.

Figure 29 – click to enlarge

Figure 30 – click to enlarge