SU244895A1 - Blade of bearing propeller - Google Patents

Description

Union of Soviet

Socialist

Republics

Iv-r j

USSR State Committee for Inventions and Discoveries

DESCRIPTION OF THE INVENTION

TO AUTHOR'S (61) Additional cav.svid-wu (22) Declared 2411.67 (21) 1199417 / 40-23 with the addition of application No. (23) Priority -

Published 1/15/81 · Bulletin No. 2

Date of publication of the description 1501Я1 (72) Author of the invention

A.M. Lepilkin (71) Applicant si) 244 895 (51) M. Cl

B 64 C 27/46 (53) UDC 629.7.

.035.62 (088.8) (54) SCREW BLADE

Known rotor blades, consisting of a spar, ribs and casing, having a bend in one direction or generally rectangular. The total rate of cell concentration on the part of the ^e tsevoy close to the speed of sound. Therefore, at maximum and even cruising speed modes, there may be local zones of supersonic air velocities on the Lobes, the presence of which is associated with additional wave resistance, which can be several times greater than resistance at subsonic flow speeds, which, in turn, requires significant costs power. Known saber-shaped blades with a deviation of the axis backward reduce the wave resistance, but are unsuitable due to the large bending and twisting moments and air centrifugal forces arising due to the curved axis of the blade.

The purpose of the invention is the reduction of wave resistance, bending and torques.

It is achieved by the fact that the end part of the blade up to one third of its length is made sickle-shaped in plan, convex side forward in motion, 30 tapering toward the end by 2.5 - 3.5 times and with the aerodynamic axis deviating from the straight axis of the main part of the blade to 15 ° forward and up to 60 ⁰ back.

In FIG. 1 shows a general view of the blade in plan; in FIG. 2 - its crescent part.

The blade consists of a rectilinear part 1 and a crescent end part 2, which can be made of straight or curved segments. The aerodynamic axis 3 of the crescent part 2 of the blade deviates forward to 15 °, and back to 60 °. The narrowing of the crescent to the end decreases by 2.5 - 3.5 times, which reduces bending and torque.

The proposed blade increases the efficiency of the rotor.

Claims (1)

The rotor blades are known, consisting of a spar, ribs and skin, having a bend in one direction or generally rectangular. Their total speed on the elements of the end part is close to the speed of sound. Therefore, at maximum and even cruising speeds on the blades, there may be local zones of supersonic air velocities, the presence of which is associated with additional wave impedance, which may be several times greater than that at subsonic flow rates, significant power costs. Well-known saber blades, with the axis deflected back, reduce the wave resistance, but are unsuitable because of the large bending and torsional moments and centrifugal air forces due to the curved axis of the mouth. The purpose of the invention is to reduce wave resistance, bending and torsional moments. The tip toward the end is 2.5–3.5 times and with a deviation of the aerodynamic axis from the linear axis of the main part of the blade to the front and up to 60 back. FIG. 1 shows the general view of the blade in plan; in fig. 2 - her sickle part. The blade consists of the straight part 1 and the crescent-shaped end part 2, which can be made of straight or curved segments. The aerodynamic axis 3 of the sickle-shaped part 2 of the blade deflects forward to 15, and backward to 60 °. The constriction of the sickle-shaped part by the end decreases 2.5 - 3.5 times, which reduces bending and torsional moments. The proposed blade increases the efficiency of the rotor. Claims of the rotor blade, comprising a spar, ribs connected to it and a skin, characterized in that, in order to reduce the wave resistance, bending and torsion. Moments, the blade at the end to one third of it