Yutaka Tanaka, Sayako Sakama, and Ryushi Suzuki

Abstract:
With a view to environmental compatibility, energy saving, cost reduction, and high performance and efficiency, one trend in hydraulic systems, particularly in mobile markets, is to design them to be more compact, require less hydraulic fluid in the reservoir, and use their working hydraulic fluid longer. Air bubbles entrained in working hydraulic fluids have greatly detrimental effects on the function and lifetime of hydraulic fluids, components, and systems. A bubble eliminator using a swirl flow that can eliminate air bubbles from working hydraulic fluid has been proposed and developed by our smart and clean hydraulic project. This paper focuses on technical issues related to air bubbles, the aging process of hydraulic oil, and a field test of the performance of the bubble eliminator.

Keywords: bubble eliminator, excavator, hydraulic system, oil degradation, oil reservoir