The Shapes of Teeth of Circular Saw Blade and Their Influence on its Critical Rotational Speed

Abstract

The main problems during cutting with circular saw blade are inaccurate cut, low quality of surface, high level of noise. These adverse effects are related to oscillation of circular saw blade. This oscillation cause adverse effects not only on workpiece but also on tool. In some case the circular saw blade reaches the value of critical rotational speed which leads to its instability and cause the oscillation of blade which may leads to destruction of tool. So the reduction of the amplitude of oscillation is essential for removing the adverse effects. This paper deals about influence of shapes of teeth as a type of modification that has positive effect oncritical rotational speed of circular saw blade. The parameters of studied models of circular saw blade were 42 number of teeth and the height of teeth with slice from sintered carbide was 14 mm. The variable parameter was the ratio between surface of teeth and surface of teeth gap. In this study was used computer software Creo Parametric 1.0 for obtaining natural frequencies of studied models. This software uses in analysis finite element method (FEM). There were done some steps to idealize the models. For calculating static and dynamics natural frequencies of modelswere used modal analysis. The critical rotational speed was calculated from obtained results by Creo Parametric 1.0 and compared on 5 models of tool.