Análise do desgaste superficial prematuro sofrido por engrenagens utilizadas no acionamento de uma moenda de cana de açúcar

Abstract

This work presents an analysis of the premature surface wear suffered by two cast iron spur gears manufactured in 1940 driven by a SAE 4340 forged steel pinion with surface hardness between 50 and 54 HRC. This transmission is responsible to active a Monte Alegre sugarcane mill. In this investigation was observed that the cause of the gear wear surface is his low resistance in relation to the pinion’s resistance evidenced by visual inspection, gear surface hardness measurement by a portable durometer and surface resistance calculations provided by the American Gear Manufacturers Association (AGMA). In this way it was possible to determine the number of cycles that the gears support before they present the 1st failure signals, the time required to perform these cycles, the required face width to withstand such contact tension and lastly that these gears do not have a recommended safety level. The study concludes that the gears need to make a thermal treatment for the surface hardening in the teeth or appropriate material selection of the gear, in order to obtain a surface resistance compatible to the pinion, ensuring a good life for all system components.