JPS6358759B2 - - Google Patents

Description

Detailed Description of the Invention Field of Application This invention relates to a pitch conversion mechanism that automatically adjusts the blade angle, or pitch, of a rotor blade. This invention relates to a variable pitch mechanism that operates through a variable pitch mechanism.

Background technology Aircraft propellers, helicopter rotors,
By adjusting the pitch of rotor blades such as marine propellers, industrial fans, and wind turbines,
Since thrust, absorption torque, air volume, etc. can be easily controlled, its performance characteristics can be significantly improved.

There are a wide variety of variable pitch mechanisms, and their power uses electricity and hydraulic power, and their structure uses a mechanical movement mechanism that combines cams, links, gears, and the like.

Therefore, the variable pitch mechanism of other blade propellers generally has a complicated structure because it combines mechanical movement mechanisms, and its maintenance becomes important, as well as problems such as weight and space.

Patent No. 112472 describes a wind turbine generator installed on an aircraft, in which the rotation axis of a plurality of plate-shaped guiding blades is supported in the radial direction between a cylinder and an outer cover, and A configuration has been proposed in which the other end of a connecting rod connected to one end is connected to a connecting ring, and the connecting ring is moved back and forth in response to rotation to open and close the guiding blade via the connecting rod.

However, as many connecting rods as there are guide vanes, one connecting ring, and multiple connecting rods are required, and they are arranged around the governor, there is almost no space within the envelope that can be effectively used. It was not possible to change the pitch of large blades shaped like aircraft propellers or industrial fans.

Furthermore, in US Pat. No. 3,387,664 and No. 4,037,986, a piston housed in a cylinder is moved in the axial direction by hydraulic pressure and a spring in the chamber,
A variable pitch mechanism has been proposed that rotates each blade via a crank pin.

However, in the case of a large propeller with four or more blades as in this invention, it is necessary to make the cylinder and piston larger, and increasing the size of these parts increases the weight of the device, and the pitch of many blades increases. There was a problem in that it was difficult to generate the torque force to convert the

OBJECTS OF THE INVENTION In view of the current situation, it is an object of the present invention to provide a variable pitch mechanism that has a simple structure and a small number of parts, particularly for multi-blade propellers of aircraft.

Composition of the Invention The present invention comprises: a hub that supports a large number of blades in a radial manner; a pin that is eccentrically installed on the fixed side end face of each blade with respect to its rotation center; and a pin that faces the rotation center axis of the hub. A crown member provided with a groove in the head and rotatably attached to each of the pins, and a crown member that is inserted into the groove of each crown member and attached to all the crown members,
It consists of a control ring that is slidably supported, and a drive source that is connected to the control ring so that it can move linearly back and forth in the direction of the rotation axis of the hub. This is a variable pitch mechanism for a rotor blade, characterized in that each blade can be rotated around a pitch conversion axis at the same time.

In other words, this invention fixes a pin eccentrically to the pitch conversion axis on each fixed side end surface of a plurality of blades that are radially supported on a hub, and connects a groove facing the center of the hub to the head. The crown member provided in the crown member is rotatably attached to the pin, and the control ring is inserted into the groove of the crown member and is slidably supported.
This is a variable pitch mechanism in which a plurality of blades are connected by being supported by all the crown members, and a control ring is moved back and forth in the direction of the hub rotation axis to simultaneously rotate each blade around the pitch conversion axis.

Disclosure Based on Drawings of the Invention Fig. 1 is a longitudinal cross-sectional view of the variable pitch mechanism according to the present invention as seen from the central axis direction of the hub, Fig. 2 is a detailed longitudinal cross-sectional view of the pin on the blade end surface, and Fig. 3 is a longitudinal cross-sectional view of the variable pitch mechanism according to the present invention as seen from the direction of the central axis of the hub. FIG. 3 is a perspective view illustrating the operation of the variable pitch mechanism.

Blades are pivotally supported on the hub 1, and FIG. 1 shows an example in which eight blades A to H are radially supported by bearings 2.

As shown in FIG. 2, a pin 3 is fixed to the fixed side end surface of each blade A to H at a position eccentric to the pitch conversion axis, and a crown member is attached to the shaft portion of the pin via bearings 4 and 5. 6 is rotatably attached. The head of the crown member 6 is provided with a groove 7 having a width into which a control ring 8 described below can be inserted.

The control ring 8 is simply a ring with a predetermined diameter, and the drawing shows one having a rectangular cross section. This ring 8 is inserted into the groove of the crown member 6 provided on each of the plurality of blades A to H, and each crown member 6 and pin 3 are connected.

Next, the control ring 8 is connected to the actuator of the drive source by a link (not shown), for example, so that it can move back and forth in the direction of the rotation axis of the hub 1.
The actuator drives the hub to reciprocate in the direction of its central axis.

The control ring 8 slides up and down in the groove 7 of the crown member 6 by reciprocating in the axial direction.
The pins of each blade A to H are restrained by the control ring 8 via the crown member 6, and the pins of the blades A to H are held in place by the control ring 8 through the crown member 6, so that the pins of the blades A to H do not come off from there. It rotates around the conversion axis and the pitch is converted.

Therefore, pitch control of the plurality of blades is controlled by the amount of axial movement of the single ring 8 connected via the crown member 6 attached to the pin 3.

In other words, conventional mechanisms that perform pitch conversion using pins placed eccentrically with respect to the pitch conversion axis on the end face of the blades often use separate links between the actuator of the power source and the pins of each blade. However, in the case of this invention, all the blades are connected by the single control ring mentioned above, which reduces the number of parts, reduces weight, and requires a large amount of space. Not etc.
This is a particularly advantageous mechanism for multi-blade propellers.

[Brief explanation of the drawing]

Fig. 1 is a vertical view of the variable pitch mechanism according to the present invention as seen from the central axis direction of the hub, Fig. 2 is a detailed longitudinal sectional view of the pin on the end face of the blade, and Fig. 3 shows the operation of the variable pitch mechanism according to the present invention. FIG. 2 is a perspective view for explanation. 1...Hub, 2, 4, 5...Bearing, 3...
...pin, 6...crown member, 7...groove, 8...control ring, A to H...blade.

Claims (1)

[Scope of Claims] 1. A hub that supports a large number of blades in a radial manner; a pin that is eccentrically installed on the fixed end face of each blade with respect to its center of rotation; and a pin that faces the center of rotation of the hub. A crown member provided with a groove in the head and rotatably attached to each of the pins, and a crown member that is inserted into the groove of each crown member and attached to all the crown members,
It consists of a control ring that is slidably supported, and a drive source that is connected to the control ring so that it can move linearly back and forth in the direction of the rotation axis of the hub. A variable pitch mechanism for a rotor blade, characterized in that each blade can be rotated simultaneously around a pitch conversion axis.