Study_of_Resonance_Frequencies_of_Circular_Saw_Blades

3.2.1 Study of Resonance Frequencies of Circular Saw Blades

The saw blades working in sawmilling technologies are exposed to extremely hard conditions. Under the influence of continuously changing loads on cutting teeth, dynamic shocks and dust, unexpected operation failures occur (Černecký, Siklienka, 1995).

When the circular saw blade rotates it is strained by both the internal (resonance frequencies) and external forces of the cutting process (Viglaský et al, 1993). If the frequencies of the excitation forces are equal or close to the resonance frequencies of the saw blade, the strain increases (Várkoly et al, 1998), which can lead to its deterioration (Fig. 3–19, Fig. 3–20).

Very sensitive places are also the embeddings of saw blade shafts where particularly bearings show lower real durability in comparison with theoretical assumption. One of the numerous sources of the bearings damage is the cyclic strain in axial direction generated by vibrations of the saw blade after reaching the critical speeds (Fig. 3–20).