engleski

Some possibilities of reducing circular saw idling noise

In this study the sound pressure level of differently designed circular saw blades are investigated during idling. Nine blade samples were used: three differently designed blade bodies (without slots, with four radial slots and with four slots with copper cork), each of three different diameters (260 mm, 280 mm and 300 mm). The sound pressure level was measured at different rotational frequencies ranging from 25 to 65 rps with the step of 1 rps. Rubber damping-rings of 80 mm in diameter and 0,3 mm thick were placed between the sawblade and the collars and the emitted noise was measured. Due to the whistling sound the blades without slots emitted very high sound pressure levels. There were no significant changes when the rubber damping-rings were used. The use of the rubber damping-rings on the samples with radial slots eliminates the whistling noise. The saws with copper corks did not emit a whistling noise at all and their aerodynamic noise was 2-3 dB(A) lower than the aerodynamic noise of the saws with radial slots. The relation between sound pressure emitted by the damped idling saw and peripheral velocity can be described by the power function whit the exponent value between 4.8 and 5.2.

idling circular saw; whistling noise; noise level; rubber damping-rings

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