HIGH-EFFICIENCY PROPELLER BLADE WITH INCREASED WORKING SECTION SURFACE Russian patent published in 2015 - IPC B63H1/26 F04D29/38 B64C11/18 

FIELD: transport.

SUBSTANCE: propeller contains flat surface (13.2) which passes along blade rear surface (13) and has width equal to 1/3 of blade width (13), rear radiused surface (13.1) which crosses the flat surface (13.2) and has radius R which is equal to 2/3 of rear surface width thus complementing the remaining part of rear surface. On free end of rear surface radius (13.1), contact surface (13.3) with radius of 1.5 R crosses propeller rotation plane, so that the contact surface forms angle of 3-9 degrees. The radiused surface (13.4) of outlet edge with radius of 0.5 R crosses surface located below half-thickness of blade edge of the mentioned inner contact surface(13.3) and flat surface (13.2), and is curved in direction opposite to inner contact surface (13.3). Distance from point of intersection of the mentioned radiused surfaces (13.1, 13.3) which have radii of R and1.5 R to surface where rear flat surface is located (13.2) is equal to 1/4 and 1/5 of rear surface projection width. Diameter F of rear surface (13.7) of blade (13) is within diameter value range of R400 to R650.

EFFECT: increased energy efficiency.

3 cl, 5 dwg, 1 tbl