Design and Application of Integrated Cooling System Against Temperature Risks of Metrobus 5th Axle Steering System

Abstract

Today, studies are carried out to extend the life of the oils used in commercial vehicles. There are many parameters which should be taken into account in these studies. In the study, especially due to the overheating problem of the hydraulic oil of the axles steered by hydraulic pressure, the radiator integration into the system was made in response to the oil overheating problem experienced in the 5th steerable axle of the Akia 25 meter bus. In this paper, subjects such as oil cooler selection, fan selection and frame application around the radiator were emphasized. Necessary measurements were made on the system and compared with the results before and after integration. Evaluations were made in line with the results obtained from these comparisons. Oil cooler was applied with 600 mm length and 200 mm width, 2 fans with Ø268.5 mm diameter and 10''LP blowing capacity and 24V power were preferred. The system consists of 7 main parts: steering axle, hydraulic unit, hydraulic accumulator, oil cooler, oil filter, pump and oil tank. Steel pipes of Ø18 mm and Ø15 mm diameter are used on the line, and oil cooler connection is provided with 5/8'', 1/2'' and 3/4'' hoses. The hoses and pipes used in the connection line have been selected to be suitable for use in the discharge and return lines. When the connection temperatures reach 80° degrees, the fans of oil cooler is activated through the integrated system, and the oil temperature is reduced to 65°, thus eliminating the risk of temperatures reaching 130° degrees before integration. As a result, the problems arising from high temperatures have been prevented, and with the more efficient operation of the system, both the oil life has been extended and the service costs have been reduced.

Keywords

• Bus
• steerable axle
• radiator
• oil life

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