Propeller have 2 to 4 blade,blade number,the more the greater the power absorption.In high-power turboprop aircraft also USES a set of propeller shaft,actual it is two counter-rotating propeller,can offset the reaction torque.On the small aircraft engine power is less than 100 kw,the commonly used double leaf wooden propellers.It is with a patchwork of wood blade on both sides and to make up torsion,middle hole connected to the engine shaft.The propeller blades at a high speed rotating centrifugal force of inertia and aerodynamic load.In high-power propeller blade root by the centrifugal force of up to 200000 cows (20 tons).In addition to the vibration of the engine and cause.High power engine generally adopts 3 and 4 propellers,and multi-purpose aluminum alloy and steel to manufacture blades.Aluminum and steel blade for solid materials we can do it thinner,is helpful to improve the efficiency of the propeller in high speed.After 70 s is made of composite material blade in order to reduce weight.
