Analysis of Friction Forces in a Micro Servo Valve for Medical Equipment

Friction forces exert more important influences on the reliabilities of a micro-valve. As the dimension getting smaller, sometimes friction forces can cause the failure of a system by stopping the parts moving. A micro servo valve is designed for medical equipment, in which the spool is directly driven by an eccentric shaft. All the friction forces acting on both the eccentric shaft and the spool are studied, and the function between critical friction coefficient under self-lock condition and the rotation angle is investigated as well.