Electronic throttle body with low friction default mechanism

摘要

An electronic throttle control system having a housing (26) and cover member (14) with a throttle valve (34), gear mechanism (40), motor (50), and failsafe or default mechanism. A spring member (80) positioned between the housing (26) and sector gear member (44) which is attached to the throttle valve shaft (36), biases the throttle valve plate (34) member toward the closed position. A spring-biased plunger member (200) biases the throttle plate (34) member from its closed position to a default or "limp-home" position. In order to reduce contact between the spring member (80) of the default mechanism and the plunger member (200), the spring member (80) can have an hourglass shape and/or the outer surface of the plunger member (200) can be minimized.