RU1807960C - Windwheel vane made of composite materials and method of its manufacture - Google Patents

Abstract

The invention relates to wind turbines and can be used in the manufacture of blades and side members of rotor blades and tail rotors of helicopters, fans and other products from layered composite materials. The aim of the invention is to increase strength and durability, reduce weight, reduce cycle and labor input of blade manufacture. The blade has a box-shaped spar 2 of variable cross section with decreasing wall thickness, the outer shell 4, consisting of at least two spiral layers of fiberglass and porous filler 3 with an integral layer that defines the specified aerodynamic profile of the blade. The spar is formed by winding the fibers along the lines of equal deviation by the zonal method, $ forming the outer shell by spiral winding the glass tape on a mandrel obtained by foaming foam in a closed form, the working surface of which corresponds to the inner shape of the outer shell. 2 pp., 4 C.p. f-ly, 5 ill.

Description

The invention relates to wind propulsion systems and can be used in the manufacture of rotor blades and side members of rotor blades and tail rotors of helicopters, fans and other hollow articles made of laminated composite materials.

The purpose of the invention is to increase strength and durability, reduce weight, and also reduce the cycle and labor input of blade manufacture.

In FIG. 1 shows a blade; general form; in FIG. 2 - section AA in fg. 1; Fig. 3 shows a method of applying the first zone to the mandrel by winding; in FIG. 4 is a method for forming a spar; Fig. 5 shows a method for forming a shell of a butt part.

Here, the embedded element with the docking flange 1 is embedded in the spar 2. A filler 3. is applied to the spar, which covers the outer shell 4, which rests on the strips 5.

The blade of the wind wheel consists of a power element in the form of a box spar 2, at one end of which a metal embedded element with a docking flange 1 is wound. The spar has an irregular polygon in cross section with a decreasing perimeter as the distance from the axis of rotation of the blade. In order to achieve uniform tension and reduce weight, it is necessary that the wall thickness of the spar decrease with increasing radius. To achieve this effect, the spar contains layers of various lengths arranged in zones so that their number as the radius of the blade increases. It decreases, and the thickenings formed in the reverse zones of the turns are removed. In addition, the laying angle of the glass fibers in each layer decreases from the beginning of the turn to its end, since with a decrease in the laying angle the layer thickness also decreases.

On the surface of the spar there is a filler in the form of foam, foamed in a closed form, the working surface of which corresponds to the inner contour of the outer shell 4, and also strips 5, which provide rigid support to the side walls of the outer shell 4. The outer shell consists of at least two spiral-helical layers of fiberglass based on a glass tape impregnated with a binder; the turns of which are laid end-to-end and oriented at an angle to the longitudinal axis of the blade, and the turns of the subsequent layer are offset by half the width cients and oriented at the same angle but in the opposite direction.

The essence of the method is illustrated in the drawing, where in FIG. 3 shows a method of applying to the mandrel the first zone 6 by winding and the location of the segments of the thickening 7.

Fig. 4 shows a method for forming the entire spar by winding zones 8, 9, 10 and a method for sealing a mortgage element 1 with clamping ring layers 11. Fig. 5 shows a method of forming a shell of the butt part 12, wound with annular layers 13 and layers of the main shell 14 and 15.

The blade of the wind wheel is made as follows.

A plug-in element with a docking flange is mounted on the mandrel and secured against rotation. The mandrel is mounted on a numerically controlled winding machine. On top of the mandrel and the insertion element, a first zone of plastic is applied from glass fibers impregnated with a binder, formed into a tape by spiral winding along curves of equal deviation. In this case, the control program of the winding machine

calculated so that the winding angle

as far as the connecting flange (from

start winding) continuously decreased.

This is because in order to ensure

the equal tension of the spar, while reducing the cross-sectional area, the wall thickness should decrease. The thickness of the wound spiral layer in any section under consideration is calculated by the formula:

 COSOa COS (A

d.

 and

where Pa, Oa - the outer perimeter and the angle of winding of the largest section;

P |, sc - the outer perimeter and the winding angle of the 1st section;

yes is the thickness of the layer in the largest section.

It follows from the formula that, with a decrease in the winding angle, the layer thickness in the considered section decreases, and with a decrease in the outer perimeter, the layer thickness in the considered section increases. However, since a decrease in the layer thickness due to a decrease in the winding angle cannot compensate for an increase in the layer thickness due to the difference in perimeters, then designate the spar in one zone, i.e. malfunctions of the same length do not appear to be black. Therefore, the most optimal wall thickness of the spar can be obtained by zonal winding.

After winding the first zone, the thickening resulting from the reverse of the turns is cut off and removed. Next, a second zone is wound, which lays on top of the first and covers a new section of the mandrel. Similarly, the thickened end of the zone is cut and removed. All subsequent zones are wound in the same way. The reverse zone of the turns (thickening) of the last zone is laid on the technological part of the mandrel. Then, the wound layers of all zones are pressed against the neck of the embedded element (to the area adjacent to the docking flange) using the ring layers with the same fiber, after making an annular cut on all layers located on the technological part of the mandrel. This is ensured by the tension of the glass fibers on the tape mechanism of a wound machine. Next, separation and wickel layers are applied and the binder is cured in the oven. After that, the mandrel is removed, glued onto the outer side surface of the spar of the strips, on which the outer shell then rests, fit into the mold, fill in the free volume of the mold with the necessary weight of the pre-prepared grain size of the semi-finished foam material and foaming the latter in the furnace according to the required mode. Next, the product is removed from the mold, the overburden is cleaned (if necessary) and mounted on the winding machine. The butt portion of the outer sheath is formed by applying pre-impregnated and cut fiberglass, with the extreme sections being wrapped with several layers of fiberglass. The outer shell is then formed by winding from pre-soaked glass tape. The winding is performed in increments equal to the width of the tape, i.e. the turns are adjacent to each other end-to-end and oriented at an angle to the longitudinal axis. The subsequent layer is laid with an offset of half the width of the tape so that the joints of the coils do not coincide. In this case, the turns are inclined to the longitudinal axis at the same angle, but in the opposite direction. Winding is carried out until the required thickness of the outer shell is reached. The product is then placed in a mold whose inner contour has a precise aerodynamic profile of the blade and is placed in a furnace where the binder cures. The product is then removed from the mold and the drug coating is applied.

Claims (6)

1. The blade of the wind wheel made of composite materials, containing a box-shaped spar of variable cross-section, a mortgage element with a docking flange, a filler of lightweight material of a porous structure between the spars and the outer shell with a decorative coating, characterized in that, in order to increase the strength and 0 durability, weight reduction, as well as reducing cycles and the complexity of manufacturing, the spar is made of spiral layers of fiberglass with variable 5 by a wall thickness decreasing with increasing radius of the blade. 2. The blade according to claim 1, characterized in the fact that as a placeholder use polystyrene with an outer surface that repeats the inner shape of the outer shell. 3. The blade according to claim 1, with the fact that the outer shell is made of at least two spiral-helical 5 layers of glass tape impregnated with a binder. 4. A method of manufacturing a blade of a wind wheel from composite materials, including the manufacture of a spar 0 with docking eyes, placement of filler made of light material, application of the outer shell to the surface of the spars and filler of the outer shell, thermosetting and decorative coating, characterized in that, in order to increase strength and durability, reduce weight, as well as reduce the cycle and laboriousness of manufacturing, the blades, the spar are made with a variable wall thickness by winding the spiral layers along the lines of equal deviation by the filling method, and with the distance from the axis of rotation of the blades, the length of Doi subsequent zones increase, and 5. The winding angle in each layer is reduced, while the resulting thickenings in the places of reverse turns before the winding of the next layer are cut and removed. 5. The method according to claim 4, characterized in that the aggregate is placed by filling the dry semi-finished foam material and foaming it in a closed form with a working surface corresponding to the inner surface of the outer shell. 5 6. The method according to p. 4. characterized in that the outer shell is applied by spiral winding of at least two layers of fiberglass impregnated with a binder, the turns of the first layer being butt and oriented at an angle to the longitudinal axis, and the turns of the second layer are tilted and tilted at the same angle, but they are pulled half the width of the wound back side. / -L l06er # 1 // 77o FIG. 2