This mechanism uses a rotating pink shaft to drive a yellow sliding sleeve that moves along the axis of the propeller hub. That sleeve connects to a green eccentric link which, when displaced, forces all three blades to twist in unison and change their pitch angle.

Components — At the center is the pink shaft, fitted with small gear-like threads that push the yellow sleeve forward or backward as the shaft turns. The yellow sleeve carries an eccentric pin that engages a green rod arranged off-center within the propeller hub. This green rod links to three internal levers, each connected to a blade root. The three pale green blades pivot around their own axes and receive the same angular input from the shared eccentric linkage.

How it works — The pitch change depends on the sliding motion of the yellow sleeve. As the shaft rotates, the threaded interface advances or retracts the sleeve along the hub. Its eccentric pin shifts the green rod sideways, and that displacement twists the internal levers that control the blades. Because all three levers receive the same push, the blades rotate by equal amounts, increasing or decreasing pitch smoothly.

Applications — Variable-pitch propellers are used in marine propulsion, small boats, and model craft where efficiency and thrust control are important. Adjusting pitch on the fly allows engines to maintain optimal load across a wide range of speeds and conditions.

Why it matters — This axial-sleeve design packs complex blade control into a compact, sealed hub. By using one sliding element to coordinate all three blades, it offers reliable pitch adjustment without bulky external linkages or hydraulics, improving responsiveness and durability.