Corrective Maintenance of Worm Gear a Screw Press Machine with a capacity of 30 tons per hour using Wear Analysis and its response to Conus Pressure

Abstract

Worm gear is one of the main components of a screw press machine that is very vulnerable to wear. Based on the survey, it was found that the lifetime of the worm gear of a screw press machine at a palm oil mill owned by PT. Perkebunan Nusantara 4, Adolina estate, is always lower (only 700 to 800 hours) when compared to the recommended lifetime of the manufacturer (1000 hours). The wear on this worm gear needs to be minimized because it affects the performance of the screw press machine and losses on palm oil. Corrective maintenance needs to be applied to worm gear as a repair solution. Temporary corrective maintenance that has been carried out by the operator is to re-weld the surface of the worm gear. Initial analysis has been carried out by calculating the response that occurs in the worm gear due to cone pressure. The analysis results obtained that the highest wear value is located at the end of the worm gear that is in direct contact with the cone pressure. Obtained the value of the rate of wear depth of the worm gear of 0.583 mm per day with the hardness value of the cast steel material that is 215 BHN. After that, at the end of the worm, gear is modified by adding a coating plate that has been given surface hardening treatment using NiKaNa methods. The aims are to make the wear that occurs earlier on the part of the coating plate, so that repair becomes more leisurely. Based on the results of the study, it was found that the value of the hardness of the coating plates increased by 490 BHN, with the rate of wear depth decreasing to 0.256 mm per day.