US20100278656A1 - Structure an aircraft rotor blade - Google Patents

Abstract

An aircraft rotor blade structure is disclosed. The rotor blade includes a read blade part made of a pearl board and a front blade part made of a plastic material. The front blade part is connected to the front edge of the read blade part. This read blade part helps reducing the weight of the blade. The front blade part enhances the transverse strength of the read blade part and renders a center of gravity on the front edge of the blade.

Description

BACKGROUND OF THE INVENTION
• 1. Field of Invention
• The invention relates to the structure of an aircraft rotor blade and, in particular, to a rotor blade made of lighter materials and easy to control its center of gravity during its assembly.
• 2. Related Art
• A rotorcraft gains an uplifting force from the rotation of its rotor. Its tail rotor cancels the torque produced by the rotating rotor, so that the aircraft can fly stably in the air. It is thus seen that the design of rotor blades is a key factor that control the flying stability thereof.
• To achieve a better balance state of the rotor blades, the blades of many model helicopters are designed to have a center of gravity toward its front edge. The conventional blade is made of wood and thus heavier. Its center of gravity is also difficult to control. When a helicopter breaks one of its blades, the wooden blade may hurt observers. Alternatively, there are also blades made purely of pearl boards. However, they have a weaker strength. In that case, it is harder to control the flight of the helicopter.
• As shown inFIG. 3, theconventional rotor blade9 of the rotorcraft is made of a compound wood. In practice, the rear part of theblade9 has to be drilled and a heavy object has to be disposed in a recess in the front part, so that the center of gravity of the blade can fall near its front edge. However, such a blade has a higher cost because it uses a compound material, followed by machining and weight adjustment. The position of the drilled hole and the weight have to be carefully calculated. Any mistake may easily result in imbalance of the blade. As in the case of wooden blades, the blades made of pearl boards also have the same danger when they break.
• In summary, it is useful to provide a blade that is easy to manufacture and adjust its center of gravity toward its front edge. Moreover, it is highly desirable for the blade of have lighter weight and tensile strength for flight.
SUMMARY OF THE INVENTION
• An objective of the invention is to provide a rotor blade for an aircraft. The rear part of the blade is made of the lighter pearl board. Its front part uses a plastic material to increase the strength of the rear part and to move the center of gravity forward. Therefore, the entire blade is light and easy to control the position of its center of gravity. Not only can the invention enable the aircraft to achieve certain stability, the assembly cost is also lower. Moreover, the disclosed blade causes less damage when it breaks.
• In accord with the objective, the disclosed rotor blade includes:
• • a rear blade part in the rear part of the blade and made of a pearl board;
  • a front blade part in the front part of the blade, made of a plastic material, and connected to the front edge of the rear blade part; and
  • a through hole for the blade to connect to the rotor.
BRIEF DESCRIPTION OF THE DRAWINGS
• The invention will become more fully understood from the detailed description given herein below illustration only, and thus is not limitative of the present invention, and wherein:
• FIG. 1 is a three-dimensional assembly view of the invention;
• FIG. 2 is a three-dimensional exploded view of the invention; and
• FIG. 3 is a three-dimensional structural view of the rotor blade in the prior art.
DETAILED DESCRIPTION OF THE INVENTION
• The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements.
• FIGS. 1 and 2 show an embodiment of the invention. The invention, however, is not limited to this particular example.
• According to the embodiment, the disclosed rotor blade includes arear blade part1 in the rear part of the blade and afront blade part2 in the front part of the blade.
• Therear blade part1 is made of a pearl board. Its one end has anarc notch11. One side of thearc notch11 is formed with arecess part12.
• Thefront blade part2 is made of a plastic material. It is formed with a throughhole21 in the part corresponding to the arc notch for the blade to connect to the rotor (not shown). Thefront blade part2 is connected to the front edge of therear blade part1 by thermal compression bonding. After thefront blade part2 and therear blade part1 are connected, the throughhole21 of thefront blade part2 coincides with therecess part12 of therear blade part1.
• Since therear blade part1 is made of the pearl board and the its front edge is connected to thefront blade part2 by thermal compression bonding, the center of gravity of the blade thus falls at the front edge of the blade. Thefront blade part2 made of the plastic material strengthens the soft pearl board and thus the entire blade. The distortion on both ends of the blade during the flight can be reduced. Therefore, the aircraft is less likely to encounter flight instability due to an insufficient uplifting force.
• Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to persons skilled in the art. It is, therefore, contemplated that the appended claims will cover all modifications that fall within the true scope of the invention.

Claims (1)

1. An aircraft rotor blade, comprising:

a rear blade part in the rear part of the blade and made of a pearl board;

a front blade part in the front part of the blade, made of a plastic material, and connected to the front edge of the rear blade part; and

a through hole on the front blade part for the blade to connect to the rotor.

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