Electronic throttle body with low friction default mechanism

摘要

An electronic throttle control system having a housing and cover member with a throttle valve, gear mechanism, motor, and failsafe or default mechanism. A spring member positioned between the housing and sector gear member which is attached to the throttle valve shaft, biases the throttle valve plate member toward the closed position. A spring-biased plunger member biases the throttle plate member from its closed position to a default or "limp-home" position. In order to reduce contact between the spring member of the default mechanism and the plunger member, the spring member can have an hourglass shape and/or the outer surface of the plunger member can be minimized.