Hydraulic System of JD 955 Combine Harvester as Well as Presented Services based on Statistical Analysis

摘要

The JD 955 combine harvester manufactured by ICM. Company has two hydraulic circuits which are the principal circuit (dividing valve circuit) and the steering circuit. Therefore, investigation and inspection of defects of the hydraulic system used incombine, considering its functions in the machine is so significant. In this article the problems of the hydraulic system throughout JD 955 combine harvester and the way services are given for disappearing the problems, have been investigated. For this purpose some 90 combines were selected which had been supplied to the customers over the last one or two years. The 140 defects detected from their hydraulic circuits were analyzed then services supplied to the selected combines and actually after sales services were researched within some categories. Results showed that the hydraulic pump had the most problems and was spent the most expense. In addition, throughout the after sales service categories only charges of the defects had significant differencewith each other. Finally some policies suggested in order to decrease and eliminate the defects.