SU1244388A1 - Axial-flow fan blade - Google Patents

Description

The invention relates to a torus valve and can be used in axial fan blades.

The purpose of the invention is to increase the stiffness and vibration strength of an axial fan blade by reducing the concentration of stresses at the welding sites.

FIG. 1 shows a blade axial fan, a longitudinal section; in fig. 2 is a section A-A in FIG. one.

The blade of the axial fan contains a shank 1, a supporting rod 2 which is integral with it and welded with the rod 2 and between the sheet elements 3 and 4, forming a shaped feather,

welded to the rod 2 in the area of the ledges 5 and 6 and in contact with its edge 7 and the opposite face 8.

Bearing rod 2 has a length LI of 0.2-0.25 of the length LZ of the pen,

 the length La of the sheet element 3 from the back of the pen is 0.7-0.8 of its length Lz, and the chord of the same element is 0.4-0.7 of the feather chord.

During operation, tensile, bending and torsional stresses occur in the blade of the axial-flow fan of the torus. The implementation of the supporting rod 2 in the form of a triangular truncated pyramid, facing the smaller base to the periphery of the pen, allows to reduce the stresses in the joint area of the rod while the supporting rod 2 has the shape of n 2 with the shank 1. The placement of the ledges 5 of the triangular truncated pyramid facing the smaller base to the periphery of the pen, and provided on the side of the shank 1 with steps 5 and 6, located at differences 6 at different distances from the shank 1, reduces the stress concentration in the welded grooves, and placing the steps 5 and 6 at an angle to the axis EPA provides

from the shank 1 at an angle n and the reduction of stresses in the welded grooves. All to the axis of the pen, and sheet elements 3 and 4, this increases the rigidity and strength of the blade.

welded to the rod 2 in the area of the ledges 5 and 6 and in contact with its edge 7 and the opposite face 8.

Bearing rod 2 has a length LI of 0.2-0.25 of the length LZ of the pen,

 the length La of the sheet element 3 from the back of the pen is 0.7-0.8 of its length Lz, and the chord of the same element is 0.4-0.7 of the feather chord.

When operating in the blade of an axial ventilator of the torus, tensile, bending and torsional stresses occur. The execution of the supporting rod 2 in the form of a triangular truncated pyramid, facing the smaller base towards the periphery of the pen, makes it possible to reduce the stresses in the joining zone of the rod 2 with the shank 1. Placement of the ledges 5

 n 2 with shank 1. Placement of ledges 5

and 6 at different distances from the shank 1 reduces the stress concentration in the welded grooves, and the placement of the ledges 5 and 6 at an angle to the axis of the pen provides

 stress reduction in welded grooves. All this increases the rigidity and strength of the blade.

Compiled by Yu. Rusakov

Tehred I. VeresKorrektor S. Cherni

Circulation 586 Subscription

VNIIPI USSR State Committee

for inventions and discoveries

113035, Moscow, Zh-35, Raushsk nab. 4/5

Branch PPP "Patent, Uzhgorod, st. Project, 4

Claims (2)

1. AXIAL FAN BLADE. comprising a shank, a supporting rod made at the same time with it, and sheet elements welded with the rod and between each other, forming a profiled feather, characterized in that, in order to increase stiffness and vibration strength by reducing the stress concentration at the weld points, the bearing rod has the shape of a triangular truncated pyramid, facing a smaller base to the periphery of the pen, and provided on the shank side with ledges located at different distances from the shank at an angle to the axis of the pen, and leaf elements Rena to the rod in the area of ledges and in contact with its edge and the opposite edge. 2. The shoulder blade according to π. 1, characterized in that the bearing rod has a length of 0.2-0.25 of the length of the pen, the length of the sheet element from the back of the pen is 0.7-0.8 of its length, and the chord of the same element is 0, 4-0.7 from the chord of the pen. _Λ δ