JPS6220959B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pitch conversion mechanism that automatically adjusts the blade angle, or pitch, of a rotor blade, and more particularly, to a variable pitch mechanism that can simultaneously convert the pitch and the sweepback angle or advance angle.

Rotary blades such as aircraft propellers, helicopter rotors, ship propellers, industrial fans, and wind turbines can easily control thrust, absorption torque, air volume, etc. by adjusting their pitch. Performance characteristics can be significantly improved.

There are a wide variety of variable pitch mechanisms, each of which utilizes electricity or hydraulic pressure for power, and is structurally a mechanical movement mechanism that combines cams, links, gears, and the like.

For example, in the case of a high-speed propeller that has a sweepback angle, it is desirable to convert the pitch and sweepback angle for efficient use. However, the conventional pitch conversion mechanism only changes the blade pitch, and cannot convert the receding angle or advancing angle at the same time.

Therefore, the present invention has a simple configuration and can convert the receding angle or the advancing angle at the same time as changing the pitch. It is intended for a variable pitch mechanism.

In other words, in this invention, the variable pitch axis is normally located within the plane of rotation of the propeller, and the blades rotate around an axis that passes through the blade cross section. It is characterized by being constructed within a plane that intersects the rotation surface at a predetermined angle.

To explain in detail, the end of the blade is bent at a predetermined angle with respect to the plane of rotation of the propeller, and the bent end is pivoted to the hub so that the tip of the blade swings around the transverse direction of the bent end as the central axis. Furthermore, a bevel gear is provided on the end surface of this blade, and a drive gear that meshes with the bevel gear is rotatably supported around the propeller rotating shaft, and the drive gear is rotated to adjust the sweepback angle of the blade using the above-mentioned central axis as a pitch conversion axis. It changes the pitch along with the forward angle.

The present invention will be explained below based on the drawings.

The blade 1 is bent so that its fixed end 2 intersects with the propeller rotating surface at a predetermined angle, and the hub 3 to which the blade 1 is attached has a hub plate bent vertically and attached to the end 2. Openings 4 are provided in parallel to each other. This blade 1 has an end 2 pivoted to an opening 4, and is attached to a hub 3 via a bearing 6 on a fixed shaft 5 that passes through the buffing plate of the end 2 and the opening 4 in the transverse direction of the end 2. It's worn.

Next, a bevel gear 7 is provided on the end surface of the end portion 2 of the blade, and a drive gear 8 that meshes with this bevel gear 7 is rotatably mounted around the propeller rotation axis. It is configured to be driven by an electric motor, hydraulic motor, etc. and rotated to any angle.

With this configuration, the blade 1 makes a pendulum movement about the fixed shaft 5, so that the receding angle or advancing angle provided on the blade and the pitch can be changed at the same time. That is, the fixed shaft 5 intersects with the propeller rotating surface at a predetermined angle, 60° in the drawing,
This is due to the configuration in which this is used as the pitch conversion axis of the blade 1.

Therefore, by appropriately selecting the planar shape of the blades and the direction of the pitch conversion axis, it is possible to simultaneously convert the recession angle or advance angle and pitch of a high-speed propeller that can be used in the transonic region, resulting in efficient pitch control. can be done.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a hub showing a variable pitch mechanism according to the present invention, and FIG. 2 is a top view taken along the line of FIG. 1. In the figure, 1...blade, 2...end, 3...hub, 4...opening, 5...fixed shaft, 6...bearing, 7...bevel gear, 8...drive gear.

Claims (1)

[Claims] 1 The end of the blade is bent at a predetermined angle with respect to the propeller rotating surface, and the end is pivoted to the hub so that the tip of the blade can swing pendulumly around the insertion axis in the cross-sectional direction of the bent end. A bevel gear is provided on the end surface of the bevel gear, and a drive gear that meshes with the bevel gear is rotatably supported around the propeller rotating shaft. A rotor variable pitch mechanism that converts the pitch along with the sweepback angle or advance angle of the blade as a variable pitch axis.