What is the name of this component (green)?

[jiayue92]

what is the green component? what is the name?

 

[Travis_King]

I don't know the name for that specific device, but it is a type of ratchet mechanism.

Edit: To further classify this, one might call it a ratcheting freewheel mechanism. The one thing of which I'm unsure how to classify, is that the ratchet mechanism is based on the deflection of the ratchet, rather than a pivoting arm-and-spring style mechanism.

 

[jiayue92]

i found the photo on google. I am looking for a plastic gear component that allow gear to turn freely in one direction, but engage in opposite direction. do u have any idea?

 

[Travis_King]

I'm sure someone makes plastic freewheels, or you could easily have it fabricated for you. As far as that specific design, I don't know.