Development of the Servo Valve with High Durability Using Split-Type Sleeve – Reduction of Wear with Ceramic Material

Reduction of leakage is a major problem in water hydraulic systems. With a servo valve, it is possible to reduce the internal leakage by reducing the clearance between a spool and a sleeve. However, because the clearance is reduced, wear tends to occur easily between the spool and sleeves when the servo valve is driven. As a result, the durability of the servo valve is reduced. Attention is paid to the durability against wear of ceramic materials, and the wear can be suppressed by using ceramics as the materials of the spool and sleeve. Thus, one can check whether the wear between the spool and sleeve can be suppressed, thereby improving the durability of the servo valve.