JPS5963299A - Counter torque rotor blade for helicopter - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

TECHNICAL FIELD This invention relates to counter-torque rotor blades for helicopters.

PRIOR ART In general, conventional counter-torque rotor blades consist of a tubular hub keyed centrally over the lateral drive shaft and closed at opposite ends by plugs of elastomeric material. It was equipped with a metal fitting to connect the

Each of these plugs serves as a pivotable connection for a tie rod (1! connection rod) projecting from both articulating ends of the hub and is pivotally connected to the articulating wing. This challenge has a tubular mount keyed by the interposition of a push (thin-walled cylinder) of elastomeric material on the interlocking tubular end of the hub.

In the rotor described above, the knobs have been chosen to be of such tubular form for the purpose of imparting rigidity to the overall structure. However, precisely because of its rigidity, the known counter-torque rotor structure has been subject to disintegration due to constant blade pitch fluctuations. This occurs because the critical frequency of these rotor blades changes with variations in the pitch of the blades, and at times a forced oscillation occurs, which results in the blade becoming dislodged within a very short period of time. there were.

OBJECTS OF THE INVENTION The object of the present invention is to provide a counter-torque rotation system which obviates the above-mentioned disadvantages and which has a simpler and more economical construction than the known rotor blades.

SUMMARY OF THE INVENTION The object of the invention is to provide a hub for attachment to a drive shaft, the hub having two arms extending across the midline of the drive shaft to opposite sides of a central portion of the hub. is established,
Said valley arm engages an articulating fork element for attaching (3) to an articulated wing, in a counter-torque rotor wing of a helicopter, said valley arm has its main axis substantially connected to said articulated wing. each fork element being tubular and keyed on said articulated plate, consisting of a long plate aligned with the line of wing pitch variation and placed substantially perpendicular to said drive shaft; and are connected at their midpoints by ball joints and at their free ends by six cylindrical pivot axes, preferably constituted by cylindrical elastomeric bearings, the axes of which This is achieved by the present invention, which relates to a counter-torque rotor for a helicopter, all characterized in that it is substantially coincident with said axis.

EXAMPLE Other features and advantages of the present invention will become apparent from the following description with reference to the accompanying figures, which illustrate one non-limiting embodiment. Helicopter - State Highway Tor (5)
+-(4) A rotor is shown comprising a central hub 2 supporting two fork elements 3 connected thereto, the fork elements 3 being connected to an articulated rotor (not shown). can be respectively connected to the wings.

The hub 2 encompasses a central portion constituted by a tubular body 4 sealed at its opposite ends by two plugs 5 and having a radial bore 6 on the other hand.

A connecting shaft 7 is installed inside the tubular body 4, and can be connected to the splined end of a drive shaft 9, which is identified to the same shaft 7 by an arrow 10, at its center. A transverse hole 8 is provided with a spline.

Opposite ends (not shown) of the shaft 7 are threaded and extend movably through respective axial holes (not shown) formed in the plug 5 to each nut 11 from the plug 5. It protrudes to be screwed together, and its action allows the axis of the drive shaft 9 to be moved laterally along the axis of the shaft 7.

The hub 2 further includes two arms 12, which arms (6) 12 have a substantially rectangular elongated shape in plan view and are located diametrically with respect to the tubular body 4.

Said plates 12 are slightly tapered at their free ends, parallel to each other and inclined to the axis of the tubular body 4, and substantially parallel to the axis of pitch variation of the associated blades (not shown). They are arranged with coincident principal axes.

The G-piece 12 has a through hole 13 in its central portion, the axis of which is substantially parallel to the axis of the drive shaft 9. 6
A ring 14 is fixedly embedded in the hole 13, and the inside of this ring 14 has a seat for a knee joint 16 of a ball joint 17 connecting the plate 12 to the fork element 3 to be articulated. 15 by a partial spherical surface. This fork element 3 has two axial projections 187M parallel to each other and the same as each other at its end facing the cylindrical body 4, and these projections 18 are connected to the connected plate 1.
Each through hole 19t- is arranged on both sides of 2 and is coaxial with each other.
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As shown in FIG. 2, each joint 16 has a through hole 20 with a diameter of
1 extends, and one end of this pin 21 with a 7-flange engages one of the two holes 19, and the other end engages with the other hole 19. The tubular pin 21 is connected on its outer side to two tubular spacers 22, each of which engages at one end the side surface of the bent joint 16 and at the other end engages one of the holes 19. The assembly comprising the ball 16 and the two spacers 22 between the two projections 18 is fixed by a screw 23 whose head is placed in contact with the flanged end of the tubular bottle 21. , whose free end is the pin 21
The other end and one spacer 22 are connected to a cooperating nut 24 via a washer 25.

Each fork element 3 has a substantially tubular shape and has an axial cavity 26 into which the end of the plate 12 to be articulated engages and which is closed on the outside by a bottom wall 27. are doing. Two plates 28 extend outwardly from the bottom wall 27, and these plates 28 are flush with each other and have a hole 29 for receiving a fixing pin (8) of an articulated wing (not shown) and a fixed bottle (not shown). 'ffi;f
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A cylindrical elastomeric bearing 32 is fixed to the surface of the wall 27 by a screw 30 with a flange 31, the axis of which substantially coincides with the axis of pitch variation of the blades to be linked. Each bearing 32 is connected by an outer cover 33 extending through an axial through-bore 34 in the wall 27 and a cylindrical plug 36 coaxial with and axially passing through the elastomeric material of the casing 33. Complete with inner sleeve 35. A pin 3 is inserted into this inner sleeve 35.
7 is slidably mounted, the outer end 38 of this pin 3'7 projects through a threaded locking flange 31 which is delayed to a tightening nut 39, and its inner end is connected thereto. It is supported by a U-shaped bracket 40 which surrounds the free end of the plate 12 to which it is connected and is fixed to this plate by two bolts 41.

Extending outwardly from each fork element 3 is a substantially transverse force arm 42, which arm 42 is provided at its free end with a fork 43, which fork 43 is arranged facing the associated nut 11. 2 for attaching a pin (not shown)
Two holes 44 are provided M, the axis of which is substantially perpendicular to the axis of the shaft 7 for connection of a pitch control link (not shown).

Effects of the Invention From the above description, it can be seen that the structure of the rotor blade 1 described above is such that the mounting for the blade is free from the connecting rod and the support bushing for the end fork element, and that It will immediately become obvious that the structure is much simpler.

Furthermore, the tubular construction of the fork element 3 allows all connecting elements between the hub 2 and the wing to be protected against impact effects.

In this rotation R1, the distribution of force is uniform (compared to that of the above-mentioned known rotary blade with reeds). In fact, rotor blade 1
In this case, the moment due to the pitch variation is absorbed by the elastomer bearing 32 and the ball joint 17 and is not effectively transmitted to the hub 2.

As a result, the plate 12, during most of its use,
The opening force transmitted through the ball joint 17 is mainly exerted by the driving tension based on the moment and the centrifugal force transmitted through the ball joint 17.

Finally, the important thing is to move the arm formed by the plate 12
The second feature is that the stone is less likely to break apart than the known tubular hub mentioned above, and changes with fluctuations in the curved surface. In other words, the hub 2 operates as an anisotropic body (with different properties depending on the direction) so that the risk of triggering an image due to wing pitch variations is virtually zero. .

[Brief explanation of the drawing]

FIG. 1 depicts, for clarity, a counter-torque rotor formed in accordance with the principles of the present invention, partially in cross-section.
In the plane shown by removing , the second factor is the first
It is a sectional view taken along 1iK. 1...rotating heron, 2...) 1bu, 3...
Fork element, 4... Tubular body, 9... Drive shaft,
12... Board, 15... Seat, 1
6...Ball, 17...Ball joint, 18...Protrusion, 21...Support pin, 26...9 cavity, 27
...Bottom wall, 32...Swivel center (114h receiving), 37...Pin, 40...Bracket, Patent applicant Costrugioni Aeronauticie Giopani Agusta Societa Belle Atzioni Patent Application Agent Yoiki Law Patent Attorney Kazuyuki Nishidate Patent Attorney Kyosuke Nakayama Akira Yamaguchi Procedural Amendment (Method) October 1980 Commissioner of the Patent Office Kazuo Wakasugi 1, Indication of Case 1980 Patent Application No. 105976 No. 2. Name of the invention: Reverse torque rotor blade for helicopter 3. Relationship with the person making the amendment. Name of patent applicant: Sustono Red Aeronaupui f-L. Date of order: September 27, 1982 (shipment date) 6. Subject of amendment (1) “Representative of applicant” column of application (2) Power of attorney (3) Drawing 7. Contents of amendment (11) (2) Announcement of attached sheets (3) Engraving of drawings (no changes in content) 8. List of attached documents (1) Request for correction 1 copy (2) Power of attorney and translation 1 copy each (3)
) Engraved drawing 1 copy (2)

Claims (1)

[Scope of Claims] 1. The hub is provided with a knob for attaching 9 fT to the drive shaft, and the hub is provided with 2 knobs extending across the entire axis of the drive shaft on both opposing sides of the central portion of the hub. In a counter-torque rotor blade for a helicopter, the rotor blade is provided with two arms, and the two arms are connected to each other, and the two arms are connected to each other by their main axes. each said fork element (3) being constituted by an elongated plate (12) substantially coincident with the axis of pitch variation of said blade and placed substantially at right angles to said drive shaft (9); The shape of gold is used,
It is keyed onto said articulated plate (12) and further connected at its midpoint by a ball joint (17), and at its free end its axis is 2! ! being connected by a cylindrical pivot stem (32) substantially coinciding with said axis of pitch variation of said blades being connected;
All reverse torque rotor blades for helicopters. 2. The front cylindrical pivot shaft is constituted by a cylindrical elastomer bearing (32).
ff A rotor blade according to claim 1. 3. Each said fork element (3) has an axial cavity (26)' into which said plate (12) engages! and the elastomeric bearing is mounted 9 through the bottom wall (27) of the cavity (26) and extends axially from the free end of the plate (12) connected to the bottom wall (27). pin that extends to (
37) The rotor blade according to claim 1 or 2, wherein the rotor blade is inserted between the rotor blade and the rotor blade according to claim 1 or 2. 4. Each bin (37) has a U-shaped bracket (40)
4. A rotor blade according to claim 3, wherein the rotor blade is connected to the end of the connected plate by. 5. The ball joint (17) is as described above; 11! Board that is asked (
12)e A ball (16) rotatably mounted in a spherical seat (15) formed through the ball (16);
16) is diametrically traversed and connected thereto by a support pin (21) extending between two axial projections (18) of said articulated fork trunk (3). A rotor blade according to any one of the claims.