Health monitoring and performance investigation of accessory belt in an internal combustion engine during critical speeds

In this paper، critical speeds of an engine were found with different conditions of engine working and the alternator. Critical speeds occur whenever the belt has maximum oscillations. During a test at critical speeds، several variables were measured. The variables were the belt length، the mass and the stiffness. Belt performance variables such as the cooler compressor pressure and temperature of the alternator were measured، too. To measure the amount of the belt slippage، the difference between ideal and actual pulley rotational speeds was calculated. Results showed that the pressure of the cooler compressor increased by increasing the belt length but the temperature of the alternator was not changed. Also، parameters of the belt such as its length، oscillation، temperature and hardness affected each other.