Development of Low-Friction Pistons for Small Scooter Engines

Small scooters have a large share of the motorcycle market because of their convenience and economy. Therefore, fuel efficiency is an important factor when customers choose products. Urban scooter users frequently use the low to medium speed range. The friction loss of the piston is a large part of the engine loss and affects the fuel consumption. The scooter piston slides horizontally. To improve the fuel consumption of scooters, it is necessary to understand the piston operating environment and improve the lubrication environment. In order to determine the thickness of the oil film required to reduce friction, we investigated the operating environment of the piston sliding horizontally at low and medium speed. As a method to control the oil film thickness, we focused on the shape of the streak. To reduce friction loss in scooters, we improved the lubrication environment of pistons.