抄録
Biodegradable and mineral oils were assessed experimentally using a swash plate type axial piston pump. Six kinds of synthetic ester type biodegradable oils, three types of biodegradable vegetable oils and the mineral oil with the viscosity grade of 46 were prepared. The discharge pressure was set at 20MPa and the oil temperature was kept at 80℃. The pressure, temperature, flow rates and the torque were monitored during the continuous operation up to 300 hours. The performance of the pump was evaluated at every 100 hour and the physical and chemical properties of the oils were analyzed. In conclusion, i) The changes in viscosity of the vegetable oils were largest; followed by the synthetic biodegradable oils and the mineral oil, and ii) The increases in the viscosity, total acid number and the color were marked while the changes in the pump performance were less shown.
