抄録
Utilization of renewable energy was attracted attention in recent years. Among them, water power generation lends itself to Japan which possesses many aquatic resources, however, a large-scale infrastructure is required to do this. We propose a new power generation method using a number of very small and light units that are biomimeticly sealed. The units, called"Bio-Star", use a polyethylene glycol (PEG) solution and Polyvinyl formal (PVF) within the shaft seals, which reproduce the elastohydrodynamic lubrication and weeping lubrication that are observed within joint cartilage. In this report, We discuss the frictional characteristics of these biomimetic seals. To measure the frictional characteristics of the PVF seal, a motor turns the sealed shaft at 20 rpm while a 100N load is applied perpendicular to the seal housing. A torque meter then measures the shaft's resistance to rotation. Moreover, PEG solutions of molecular weight 2 million and a PEG mixture of 0.5 and 0.02 million are employed for lubricating liquid. As a result, PVF seal materials with cavity diameters below 700μm showed high coefficients of friction and the PEG solution of molecular weight 2 million showed a much lower coefficient of friction compaired to the mixed solution.