JPS5852880B2 - articulated helicopter rotor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a helicopter rotor, particularly a blade, supported from a bub by a mechanism such as a spherical elastomeric bearing in a manner that allows free movement about the intersection of a pitch change axis, a lead lug axis, and a flap axis. The present invention relates to a stop device for limiting weeping (a conical downward slope of the blades) and coning (a conical upward slope of the blades) used in helicopter rotors such as the present invention.

More particularly, the present invention relates to a weeping and coning limiting mechanism which produces rolling motion on cooperating surfaces when the blade is in either extreme position and drags.

In conventional weeping prevention systems, no coning or weeping limiting devices for freely mounted blades are known.

This is because in conventional articulated helicopter rotors, the blades are not mounted for free movement in the manner described above.

Conventionally, the blades of articulated helicopter rotors are not mounted for free movement about a single point, but rather for rotational movement about some selected axis.

Also, for coning and weeping limiting devices for blades mounted for free movement, dynamic stop devices that limit the angle in the dynamic state at an angle greater than that allowed in the static state. It has also not been done in the past.

U.S. Patent No. 2,614,640, U.S. Patent No. 2,628,686,
In the conventional anti-weep devices shown in Japanese Patent Nos. 2,719,593 and 2,906,348, spherical, conical, or rotating surfaces that allow free movement of the blade relative to the bub are not used.

U.S. Pat. No. 3,282,350 discloses a weeping and coning stop device for use with elastomeric helicopter rotors, but it is of the flat pad type and does not have the advantages of the structure of the present invention. .

What is disclosed in this patent fails to provide a constant coning or weeping angle limit over the range of lead lug changes, does not provide rolling contact between the blade and its limiting stop, and does not provide a rolling contact between the blade and its limiting stop; It does not have the performance to allow normal pitch changes.

In the device of this patent, when the cone 60 is engaged, the blade is locked in its pitch change, lead-lag, and flap motions.

U.S. Pat. No. 3,501,250 discloses an articulated helicopter rotor with elastomeric bearings and anti-sag devices, but this is a variation of the flat pad and cylindrical roller type.

It is assumed that the cylindrical roller in this case does not cause rolling contact but rather slides.

This is because to create a true rolling contact, the roller must be conical and its apex must be on the intersection of the blade's lead lug axis and the flap axis; Even if it is recognized as a conical shape, the above-mentioned conditions regarding the position of its apex are not satisfied.

A disadvantage of prior art flat pad fasteners is that flat pad designs are limited to satisfying one particular lead or lug angle at a particular corning angle.

Beyond this particular lead or lug angle, the contact of the stop will be less than the required coning angle, creating point or angular contact between the stop members, resulting in significant wear between the engagement surfaces.

In order to satisfy two different weeping angles in static and dynamic conditions, the roller must have a conical surface with the apex coincident with the center of the centering device, and the engaging stop device must also be centered. It must be a conical surface with the apex coincident with the center of the determining device.

Further, the cooperating stop surfaces must be concentric with the lead lug axis to maintain the same static and dynamic weep angles throughout all phases of lead lug movement.

A primary object of the present invention is to provide a stop device for limiting weeping and coning on freely mounted blades in articulated helicopter rotors, even in static conditions such as when the rotor is started or stopped. It also allows lead-lag movement of the blade without causing a change in weeping or coning angle under dynamic conditions such as in flight where the weeping or coning angle is larger, and also allows the blade to have a maximum coning angle when the blade is at its maximum coning angle position. A line contact or a surface contact between the engaging members of the locking device that allows pitch changing movement independently without causing galling between the engaging members or inducing a pitch change even when in the weeping angle position. As shown in FIG.

According to the present invention, the engaging surface of the ring member attached to the blade and the coning and weeping prevention member is formed as a cone having an apex at the intersection of the pitch change axis, the lead lug axis, and the flap axis of the blade. Preferably, this allows true rolling contact to be achieved without galling between the members throughout the lead-lag motion of the blade.

However, in lightweight construction, other shapes such as those disclosed herein may be used, in which case it is not absolutely necessary that a pure rolling contact be made.

According to the present invention, lead-lag motion can be performed without changing the coning angle or the flap angle when the blade is in abutment with either its coning limiter or flap limiter.

According to another feature of the invention, lead lug movement in abutment against a coning or flap limit stop is accomplished without galling between the blade and the members attached to the bub.

According to yet another feature of the invention, a dynamic stop, which is a static stop, is obtained by using a mechanism responsive to centrifugal force when the blade is in slow rotation or at rest. be able to.

According to the invention, the rotatable ring member mounted on the blade, the corning limit stop, the dynamic weep stop, and the static weep stop are selected to have an apex at the intersection of the pitch change axis, the flap axis, and the lead-lag axis. It is preferable to have a conical surface or a spherical surface that engages with each other having centers on the pitch change axis and the lead-lag axis.

The corning limit stop and the static and dynamic weep stop devices are part of an interengaging spherical surface, and may constitute interengaging textured surfaces.

Another object of the present invention is to use interlocking textured surfaces between the weeping stop device and the flap restriction device mounted on the blade and bub, and to also provide corresponding surfaces on the centrifugally actuated stop member. It is an object of the present invention to provide a structure in which, when the rotor is at rest, a stop member actuated by centrifugal force due to the load of the blades is engaged by a wedge action and prevented from coming off.

According to yet another feature of the invention, the dynamic anti-weeping member is a barrel-shaped member supported by a bub such that its cross section in a plane perpendicular to the lead lug axis forms part of a circle concentric with the lead lug axis. It is.

The surface of the static weeping device that abuts the dynamic weeping device is formed, at least in part, into a similar mating barrel shape, so that the surface of the static weeping device that abuts the dynamic weeping device is shaped like a similar mating barrel so that the barrel of the dynamic weeping device can Configured to engage the mold section.

Additionally, by providing a loose pivoting support engagement between the static and dynamic weeping devices, the static weeping device will remain resilient relative to the dynamic weeping device even if there is a misalignment within the device. pivotable to maintain the barrel surfaces of the static and dynamic weeping devices in surface contact, thereby continuously aligning said ring member and the conical surface of the static weeping device, and completely can be maintained in contact.

The mating barrel surfaces of the dynamic and static weeping devices also serve to lock the static weeping device in a position between the dynamic weeping device and the ring member during static weeping operation.

Other objects and advantages of the invention will become apparent from the following description of preferred embodiments of the invention with reference to the accompanying drawings.

FIG. 1 shows an articulated helicopter rotor 10 including a rotor bub 12 mounted for rotation about an axis of rotation 14. FIG.

A plurality of blades (only one of which is indicated at 16) extend substantially radially from the bub and are adapted to rotate with the bub about axis 14 to create lift. ing.

Basically, the blade 16 is mounted on a spherical elastomer bearing 18.
or via any other suitable free movement mechanism
Supported by 2.

The bearing 28 is mounted between a yoke or loop member 20 supported by the bub and a yoke or loop member 22 connected to the blade, with the elastomeric spherical bearing 18 disposed between them. are combined with each other.

More specifically, the bub arm 24 is connected to the blade yoke member 20.
It is a part of the blade 6 deciding bearing 27 and the spherical bearing 1.
It functions to support the inner race 28 of No. 8.

The outer race 30 of the spherical bearing 18 is connected to the blade yoke 2
2, and the blade 16 is supported by the bub 12 via an elastomer spherical bearing 18 for free movement about an intersection 37 of the pitch change axis 32, the lead lug axis 34, and the flap axis 36.

Elastomeric bearing 18 is preferably formed as a spherical surface centered at intersection point 37, like bearing race surfaces 38 and 40, and includes a plurality of spaced apart spherical metal layers encased within an elastomer.

These layers are bonded together, with the outermost elastomer connected to surface 40 and the inner elastomer connected to surface 38, respectively.

The connection in this case is preferably by adhesive.

A blade sleeve 42 is connected to the blade yoke member 22 by a conventional bolt-nut member 44 threaded through holes aligned with the overlapping flanges as indicated by 46, 48, and 50.

A stub shaft 52 concentric with the pitch change axis 32 is connected to the sleeve 42 by a conventional bolt member 54 and is preferably configured to define a centering pin 56.

Centering pin 56 is also concentric with axis 32 and supports inner race 59 of spherical centering bearing 27.

Centering bearing 27 is freely mounted around point 37 by bub arm 24 .

With this structure, the blade 16 is connected to the pitch change axis 32 and the lead-lag axis 3 by the bub 12 via the spherical bearing 27.
It will be appreciated that the flap is supported for free movement about the intersection point 37 of the flap axis 36 and the flap axis 36.

Anti-weep ring 70 is mounted on stub shaft 52 for rotation about axis 32 and is supported from the shaft by journal 72.

The ring 70 can rotate freely relative to the stub shaft 52 by applying a solid or dry lubricant between the ring surface 74 and the journal surface 76 or by applying a suitable plating to the iron surface. I'm starting to get it.

The surface 80 of the ring 70 is configured in a selected shape, as described in detail below, to engage the surface 82 of the coning limiter member 84 when the blade is in its maximum allowed coning condition; It is adapted to engage a surface 86 of a static weeping stop member 88 or a surface 90 of a dynamic weeping stop member 92.

Even when blade 16 is in its maximum coning condition and surface 80 is in contact with surface 82, the blade
It is important to be able to perform a lead-lag motion without gnawing the blade or inducing a pitch change or reducing the maximum coning angle, yet allowing blade pitch change motion independently.

This is accomplished by causing ring 70 to rotate about pitch change axis 32 as it moves along surface 82 in rolling line contact.

This is also achieved when the paternity 80 is in contact with the face 86 or 90 of the weeping device, in which case the blade 1
6 is allowed to perform lead-lag motion about axis 34 by rotating about axis 32 while ring 70 contacts surfaces 86 or 90 along a rolling line.

Although not shown in the figures, a lead-lag damper, preferably of the conventional hydraulic cylinder-piston type, is connected to yoke member 22 via a damper bearing 94 that is freely movable about centering pin 96. Exercise is now allowed.

A bearing outer race 98 is connected to the lead-lag damper.

Surfaces 82, 86, and 90 are shaped to form part of an annular member that lies in a horizontal plane and is centered on lead-lag axis 34.

The cross-sectional shape of each of these planes is part of a circle concentric about the lead-lag axis 34.

Dynamic anti-weep member 92 and static anti-weep member 88 are discussed in detail below.

FIG. 2 shows that as the blade 16 moves downwardly or upwardly about the flap axis 36, the surface 80 of the rotatably mounted ring 70 moves against the coning restriction member 8 mounted on the bub.
4 and prevents further increase in blade flap movement.

Surfaces 80 and 82 have contours selected to engage each other as blade 16 lead-lags about axis 34 while ring 70 and restriction member 8
4 continues in rolling contact along the line, such contact being made without galling, and ring 70 continues to make contact with member 84.
This is done in a manner that does not induce changes in pitch or flap angle due to rotation.

Similarly, downward flap motion of the blades 16 during normal rotor operation causes the surface 80 of the ring 70 to contact the surface 90 of the dynamic anti-weep device 92, preventing further downward flap motion of the blades 16. prevent.

Again, during lead-lag movement of blade 16 about axis 34, surfaces 90 and 80 are shaped to be selected for rolling engagement along a line, and ring 70 is connected to stop device 92. This rotation is prevented from causing pitch changes, flap movements, or galling between the two.

In addition to the dynamic sag device 92, the structure shown in FIG. 2 includes a static sag device 88, which
It is a letter-shaped member which is pivoted at its legs to a bracket member 96 which is supported in the conventional manner from the bub 12 at pivot points such as 94.

In FIG. 2, the static weeping stop device 88 is shown in the position when the rotor is at a low rotation speed or when the rotor is stopped; as the rotor speed increases, centrifugal force causes the static weep stop to stop. Note that device 88 rotates clockwise about pivot point 94 and is no longer located between surfaces 86 and 90.

As best shown in FIG. 3, static weep stop device 88 includes a surface 86 that engages surface 80 of ring 70 when it is in the position shown in FIG.

Surface 86 is shaped to be selected to engage surface 80 of ring 70 during rotation of ring 70 relative to static weep device 88 and lead-lag movement of blade 16 about lead-lag axis 34. ing.

The static weeping prevention device 88 is the dynamic weeping prevention device 9.
It will be noted that it includes a surface 100 that corresponds to surface 90 of dynamic weeping arrester 92 so as to be able to overlap two.

Surfaces 80, 82, 86, and 90 may be formed in a variety of shapes as shown in FIGS. 4-6, but surfaces 82, 86, and 90 engage surface 80 of ring 70 in line contact; This provides sufficient support to keep these surfaces in contact during the lead-lag motion of the blades 16, and rotation of the ring 70 relative to the surfaces 82, 86, or 90 to prevent galling or pitch or lag angle changes. without causing any changes.
Note that it must also be configured to allow independent pitch changing movements.

It should also be noted that line contact between engaging members is preferable to point contact from a wear standpoint and allows for rolling motion characteristics between the contacting members.

As best shown in FIGS. 4 and 5, the surface of ring 70 and the surface 90 of dynamic anti-weep device 92 are frusto-conically shaped, with the surfaces extending along axis 32.
, 34, and 36, which forms part of a cone having its apex at the intersection 37.

This is best illustrated in FIG.

Also shown in FIG. 4, ring 70 and frusto-conical surfaces 80 and 90 of dynamic anti-weep device 92 are in continuous line contact, but as blade 16 lead-lags about axis 34, ring 70 The locking device 92 is rotatable relative to the locking device 92 .

This relative rotation occurs without changing the blade weep or flap or pitch.

In FIG. 4, ring 70 is shown in two positions, the solid line indicating the non-lug position and the dotted line indicating the lug position.

As can be seen in FIGS. 4 and 5, the surface 90 of the dynamic anti-weep device forms at least a portion of a conical member that is horizontal or in a plane parallel to the pitch change axis 32 and concentric with the lead lug axis 34. It is of shape.

As best shown in FIG. 5, the flap limiting member 84 is shaped to form at least a portion of a cone concentric with the lead-lag axis 34 in a horizontal plane or in a plane parallel to the pitch change axis 32. , presents a frusto-conical surface 82 in contact with the surface 80 of the ring 70, which frusto-conical surface 82 is formed from a cone having its apex at the intersection of the axes 32.degree.

Thus, as shown in FIGS. 4 and 5, surfaces 82 and 9
0 and the surface 86 (FIG. 3) consists of a truncated conical surface having its apex at the intersection point 37 and concentric about the axis 34, and the ring 70
surface 80 also has an apex at intersection point 37 and is comprised of a truncated cone concentric with lead-lag axis 32 so that when the blade is leading-lag in its weep limit or flap limit position, there is a gap between surfaces 90 and 80. Alternatively, continuous simple rolling line contact may occur between 80 and 82, with the advantage of no blade pitch changes or galling between engagement members.

As best shown in FIG. 6a, the surface 80 of the ring 70 may be spherical, defined by a radius R from a point 101 on the pitch change axis 32, and the surface of the dynamic anti-weep device. 90 is also a surface formed by radius R around point 101 when it is in contact,
Moreover, it may be formed as part of a concentric ring around the axis 34.

The surface 82 of the Corning restriction member 84 is shaped like a spherical surface 80.
is a concave surface corresponding to , and thus has a radius R.

Thus, when point 101 rotates with pitch change axis 32 about intersection point 37 or flap axis 36, surfaces 80 and 82 can come into contact.

If static anti-weep device 88 is used in the structure of FIG. 6a, surface 86 may also be made concave with radius R about point 101 when surfaces 80 and 86 are in contact.

Surface 86 may also be concentric about lead-lag axis 34.

In Fig. 6b, the curved surfaces of surfaces 90, 80, and 82 are the lead-lag axis 3.
4. This shows that the radius R having the center on 4 may be used.

The advantage afforded by the construction shown in FIGS. 6a and 6b is that when the blade is at rest, the static weeping device 88 stops members 70 and 9, as best shown in FIG.
2, thereby preventing the static weeping device 88 from being forced out of position between members 70 and 92 by the weight of the blade. It is.

Thus, with or without the corning restriction member 84 shown in FIG. The blade 16 can weep downward until the blade 16 does not affect the blade pitch and allows the blade pitch to be changed while keeping the maximum weep angle constant and causing galling between the contact surfaces. It will be understood that lead-lag movement can be performed freely without any interference.

These all include a surface 80 of the ring 70 and an engaging surface 82 of the coning restriction device 84 or weep stop device 8.
This is due to the continuous line contact between the surfaces 86 and 90 of 8 or 92 and a rolling motion.

The blade 16 allows changes in blade pitch independently of lead-lag motion without affecting blade pitch, yet maintains a certain limit of upward coning or downward weeping motion of the blade. Moreover, lead-lag movement can be freely performed around the axis 34 without causing galling between the contact surfaces.

This includes a surface 80 of ring 70 and an engaging surface 82 of corning restriction device 84 or weep stop device 88.
Alternatively, a continuous rolling contact movement occurs between surfaces 86 or 90 of 92.

Turning now to FIGS. 8-14, the structure shown here relates to the structure of dynamic and static anti-weeping devices.
This embodiment differs from the embodiment shown in FIGS. 7 to 7 in the following points.

In Figs. 8 to 14, parts corresponding to those in Figs. 1 to 7 are indicated by the same reference numerals, and therefore, the parts that are different from those shown in Figs. 1 and 7 are indicated. I will only explain.

In FIG. 8, centering bearing 27 is also a spherical elastomer bearing constructed in a manner similar to bearing 18.

Centering bearing 27 comprises layers of elastomer and rigid material stacked on top of each other centered at the intersection 37 of pitch change axis 32, lead lug axis 34, and flap axis 36.

The outer elastomer layer is bonded to surface 62 of bearing outer race 60 and the inner elastomer layer is bonded to surface 64 of bearing inner race 59.

Both surfaces 62 and 64 have centers of curvature at intersection 37.

The inner race is formed on the centering pin 56 and is connected to the stub shaft 52 by a bolt 58.

As shown in FIGS. 1-7, an anti-weeping ring 70 is mounted on the stub shaft 52 so as to be rotatable about the axis 32, and is supported by the bearing via a journal 72.

The ring 70 can freely rotate relative to the stub shaft 52 by applying a solid lubricant, a dry lubricant, or a suitable plating between the ring surface 74 and the journal surface 76. .

The surface 80 of the ring 70 is conically shaped so that it engages the surface 82 of the coning limiter 84 when the blade is in its maximum coning position, and is adapted to engage the surface 82 of the coning limiter 84 . and a surface 90 of the dynamic weeping device 92.

In this case, when blade 16 is in its maximum coning position, surface 80 is in contact with surface 82, but the blade is
It is important to be able to perform lead-lag motion without galling between the contact surfaces, without causing changes in pitch or flaps, and while allowing independent pitch change motion.

This is accomplished by the ring 70 rotating about the pitch change axis 32 as the ring contacts the surface 82 and rotates.

The same is also accomplished when surface 80 contacts surface 86 or 96 of the anti-weep device, in which case blade 16 also rotates along axis 32 as ring 70 contacts surface 86 or 90. By rolling around the axis 34, a lead-lag movement can be performed.

Surfaces 82, 86, and 90 lie in the horizontal plane and are formed as part of an annular portion of a conical or barrel member centered on lead-lag axis 34.

The cross-sectional shape of each of these surfaces is part of a circular section concentric with lead-lag axis 34.

Dynamic anti-weep member 92 and static anti-weep member 88 will be described in detail below.

FIG. 12 shows a centrifugally actuated static anti-weeping member 8.
8, a wedge-like retention mechanism is shown in which the engaging surface 8
6 and 80 are conical, and engaging surfaces 90 and 10
0 is barrel-shaped and concentric about axis 34, with surface-to-surface contact occurring between the engagement surfaces.

It should be noted that face-to-face contact or line-to-line contact is preferred over edge or corner contact from the standpoint of wear during rotation.

When the ring 70 moves due to the deflection of the bearing 18 so that the surfaces 80 and 86 do not match up and make perfect contact, the structure of the present invention corrects the misalignment between these conical surfaces and creates a gap between them. can be made to make full contact.

9, 10 and 11 show the structure of the dynamic and static weeping device in more detail.

The dynamic anti-weep device 92 is supported from the bub 12 through a bracket member 102 that includes legs 104 and 106 that are connected to the hole 10.
8 and 110 by a conventional method such as passing a bolt through.

The leg members also include projecting ears or ring members 112 and 114 and include the end of the central cylinder member 116.

Cylinder member 116 carries an annular or barrel-shaped member 118 disposed between ear members 112 and 114.

The dynamic anti-weeping member 92, particularly the barrel member 118, is cut by several planes that are perpendicular to the drag axis 34 and that cut through the barrel member and extend in a circle concentric with the axis 34. oriented and shaped to form a section.

The surface 100 of the static weep stop device 88 is barrel-shaped, at least in part, as shown in FIG. ing.

Surface 80 of ring 70 and surface 8 of static anti-weep device 88
6 is a conical surface having an apex at point 37.

Members 116 and 118 may be integrally made;
There is no need for member 118 to rotate relative to member 116.

A through pin 120 extends through member 116 and loosely and rotatably supports static weeping stop member 88 .

Thus, when the blade 16 is rotating slowly or at rest, the spring 122 (FIG. 8) extending between the bub 12 and the static anti-weep device 88
is pulled toward the position shown in FIGS. 8-11, whereby the conical surface 86 of the anti-weep device 88 is pressed against and in contact with the conical surface 80 of the ring.

When surfaces 80 and 86 come into contact and the weight of blade 16 moves weeping stop 88 relative to pin 120, barrel surface 100 of static weeping stop 88 becomes a dynamic weeping stop rigidly supported by bub 12. Surface contact is made with barrel-shaped surface 90 of device 92 .

124 between the static weeping device 88 and the through pin 120
The loose engagement at points 126 and 126 causes the anti-weep device 88 to rotate about the pin 120;
Contact between surfaces 90 and 100 remains as the surfaces 86 and 80 are rotated into a position that creates perfect alignment and contact.

Therefore, the weight or dynamic force of the blade 16 being exerted on the static weeping device 88 is reduced by the static weeping device 88
It is transmitted to the dynamic anti-weeping device 92 through the bracket 102 and then to the bub 12.

In this case the force bypasses pin 120 and therefore pin 1
No load is applied to 20.

When the rotational speed of the blade increases sufficiently, the counterweight 123 of the static weeping prevention device 88 is actuated by centrifugal force to rotate the static weeping prevention device 88 clockwise from the position shown in FIGS. 8 and 12, surface 86 is brought to a position farther from surface 80 of ring 70, thereby causing blade 16 to move downwardly at a greater angle until surface 80 of ring 70 contacts surface 90 of dynamic anti-weep device 92. allow yourself to be

Blade weep loads are transferred to the bub 12 through the dynamic weep stop device 92 and the bracket 102.

When using a weeping prevention structure as shown, the engaging surface 8
Preferably, 0, 86, 82 are frustoconical.

Furthermore, the barrel-shaped member 11 has a concentric cross-section about the axis 34.
8 provides continuous rolling contact between surfaces 80 and 90.

Thus, the blade 16 can weep downwardly until the surface 80 of the ring 70 contacts the engagement surfaces 86, 90 of the static or dynamic weeping devices 88, 92, and the blade 16 without causing any change in
It is understood that it is possible to independently change the pitch while maintaining a constant sagging angle or downward flap angle, and to freely perform lead-lag movement without causing galling between the engaging surfaces. It will be.

This means that there is a continuous full rolling contact between the surface 80 of the ring 70 and the surface 82 of the engaging flap limiter 84 and that there is continuous full contact between the surfaces 80 and 90. It depends on things.

The blade 16 allows pitch-changing movement without affecting pitch and independent of lead-lag movement, while maintaining constant upward flap and weep angles, and creating galling between the contact surfaces. Therefore, the lead-lag movement can be freely performed around the axis 34.

This results in continuous rolling between the surface 80 of the ring 70 and the engaging surface 82 of the flap limiter 84 and between the surfaces 86 and 90 of the static weep stop device 88 and the dynamic weep stop device 92. It depends on the existence of contact.

13 and 14 illustrate a modification 150 of the anti-weeping device.

Anti-weeping device 150 is also actuated by centrifugal force and
rotatably mounted about an axis 154 by 52;
Its static position indicated by a solid line in FIG.
It is possible to move between its dynamic positions shown in dotted lines in the figure.

Springs 156 and 158 bias the anti-weep device 150 to its static position, and when centrifugal force is applied to the counterweight 160, that force overcomes the biasing force of the springs 156 and 158, causing the anti-weep device to bias into its static position. It is adapted to be rotated to a dynamic position.

The cam carrying member 162 of the weeping prevention device 150 is connected to the pin 15
It has a hole 164 into which pin 2 is press-fitted, in this case pin 1
52 have leg members 168 and 1 extending from the bub arm 24 at both ends.
It is loosely attached to 70 by a bushing as shown at 166.

Springs 156 and 158 are connected to anti-weep device 150 by removable attachment pieces 172 and 174, respectively, and to bub arm 24 by removable attachment devices 176 and 178, respectively.

The member 162 includes a static conical cam surface 180 which is conical about the lead-lag axis 34 when the blade is in a low speed rotating condition as shown by the solid line in FIG. It is adapted to engage the conical surface 80 of the ring 70 when in the stopped static position.

When the rotor is rotating normally, the centrifugal force causes the counterweight 160 to move the weeping stopper 150 to the position shown by the dotted line in FIG.
It is kept in contact with the

In this case, a dynamic conical cam surface 184, also conical about the lead-lug axis 34, is adapted to engage a surface 80 of the ring 70.

In the structure shown in FIGS. 13 and 14, the ring 70
The conical surface 80 of the weeping stop device 150 is connected to the camming surface 18 of the weeping stop device 150 according to whether the device is in the static position shown in solid lines or in the dynamic position shown in dashed lines in FIG.
0 or 184, thus roller 70 is in line contact with surface 18
It will be appreciated that by simply rolling along 0 or 184, line contact can be maintained therebetween and lead-lag or pitch-changing motion can be achieved without galling.

It will be appreciated that the anti-weep device 150 shown in FIGS. 13 and 14 is structurally different from that shown in FIGS. 10 and 11, but operates similarly.

[Brief explanation of drawings]

FIG. 1 is a side view of an articulated helicopter rotor, partially cut away for illustrative purposes, showing the static and dynamic anti-weeping devices and coning restriction devices at the joints of the helicopter rotor; It is shown supported by the rotor bubble via a spherical elastomer bearing so that it can move freely around the intersection of the pitch change axis, lead lug axis, and flap axis. FIG. 2 is a somewhat enlarged side view of the static and dynamic weeping arrester and coning restriction device. FIG. 3 is a diagram taken along line 3--3 of FIG. FIG. 4 is an illustrative plan view showing the cooperation between the anti-weeping member shown in FIG. 2 and the rotating ring member attached to the blade. FIG. 5 is a side view showing the structure shown in FIG. 4 with a flap restriction device added. 6a and 6b are side views showing an example of correcting the contact between the uneven surfaces of the weeping prevention member shown in FIG. 2, the flap limiting stopper member, and the ring member attached to the blade. Is figure 7 the line of figure 3? FIG. 7 is a cross-sectional view taken at line -7, and is a diagram illustrating a modification example when the contact surface is a spherical surface. FIG. 8 is a view similar to FIG. 1 showing an articulated helicopter rotor with a modified static and dynamic weeping system. FIG. 9 is a view taken along line 9--9 of FIG. FIG. 10 is a side view of the static and dynamic weeping device of FIG. 8; FIG. 11 is a cross-sectional view taken along line 11--11 in FIG. 10. FIG. 12 is a cross-sectional view taken along line 12--12 of FIG. FIGS. 13 and 14 are views corresponding to FIGS. 10 and 11 showing another modified example of the static and dynamic weeping prevention device. 10...Articulated helicopter rotor, 12...
...Rotor bubble, 14...Rotation axis, 16.
... Blade, 18 ... Elastomer spherical bearing, 20, 22 ... Yoke member, 24 ...
...Bub arm, 27...Blade 6 decision bearing, 32...Pitch change axis, 34...
・Lead lug axis, 36... Flap axis, 3
7... Intersection of three axes, 70... Ring, 84... Corning restriction member, 88...
... Static weeping prevention device, 92 ...Dynamic weeping prevention device, 150 ... Weeping prevention device, 160
...Counterweight.

Claims (1)

[Claims] 1 A rotor bub 12 rotatably mounted around the rotor rotation axis, a pitch change axis 32, a lead lug axis 34, and a flap axis 36 that intersect with each other at one common point 37.
at least one helicopter blade 16 protruding substantially radially from the rotor bub; and at least one helicopter blade 16 supporting the helicopter blade 16 from the rotor bub 12 so as to be movable about the intersection 37 of the respective axes. a bearing 18 mounted on the helicopter blade 16 at a position radially outward from the intersection 37 with respect to the rotor rotational axis and rotatable about the pitch change axis 32 relative to the helicopter blade; a truncated conical surface 8 that is part of a conical surface having an apex located at the intersection point 37 and concentric with the pitch change axis 32;
0 and a weeping stop device 92 having a frusto-conical surface 90 connected to the rotor bub 12 and having an apex located at the intersection point 37 and being part of a conical surface concentric with the lead lug axis 34. Articulated helicopter rotor with.