MARINE PROPULSOR Russian patent published in 2000 - IPC

FIELD: shipbuilding; manufacture of low- noise propulsors, for example propellers. SUBSTANCE: propulsor has boss with blade roots and inserts which are flush with their streamlined surface; each insert is mechanically secured forming at least one streamlined surface of blades. Inserts are located along trailing edge of blade; film gasket made from vibrodampening material is laid between surfaces of each insert and blade. Size of insert along chord of blade section profile is no less than 0.1 of length of profile chord and its thickness is equal to 0.1 to 0.5 of respective local thickness of blade section profile. Total length of inserts along trailing edge of blade is no less than 1/3 of its length. Boss has circular recess formed by end flanges where blade roots are located. Blade roots are connected with boss by means of pin screws fitted at angle relative to axis of propulsor for pressing each root to surface of circular recess, flanges and adjacent roots for change and fixation of force of their tightening-up. Film gasket made from vibrodampening material is laid between surfaces of adjacent roots and roots with boss. EFFECT: reduced level of blade vibration and noise caused by operation of propulsor. 4 cl, 4 dwg