J0230101 潮流発電への適用を目指した生体模倣シールのトライボロジー特性([J023-01]多相界面問題とバイオ、エネルギー、環境との関係セッション(1))

Abstract

Reduction of the mechanical loss due to friction between two surfaces in motion is necessary to use natural energy resources effectively. A biomimetic bearing with ability of water sealing was proosed to expect the reduction of the mechanical loss for use in micro-&cluster-generation Systems as water power generators. The components of the bearing with sealing system has a rotating shaft sliding on the counterface made of polyvinyl formal (PVF) lubricated by polyethylene glycol (PEG) solution. The PVF which has hydrophilic and coutinuous porous structure promotes the elastohydrodynamic lubrication and weeping lubrication that are observed within synovial joint. In this report, durabillity of the bearing is discussed. The PVF material with porous diameters of 700 μm was adopted for the counterface material for a rotating shaft of 20 rpm. A load of 100 N was applied perpendicularly to the housing of bearing system. Two PEG solutions, one of molecular weight 2 million and the other a mixture of 0.5 and 0.02 million, were adopted as lubricating liquids. A tensile test was carried out after the friction test. A PEG solution with a molecular weight of 2 million produced a much lower coefficient of friction when compaired to the mixed solution. The maximum tensile force of PVF did not change after the friction test, but the elastic modulus increased in comparison with that which was assessed before the frictional test. It is shown that the PVF bearing with a excellent duability for sliding distances as high as 25,000 m, and that the molecular chains of PVFs might orientate to frictional direction.