CN118457917A - Cross-axle universal hinged hub for tiltrotor aircraft and working method thereof - Google Patents

Abstract

The invention belongs to the technical field of tilting rotor craft, and discloses a cross-shaft universal hinged hub for a tilting rotor craft and a working method thereof; the cross-shaft universal-joint hub for a tiltrotor aircraft includes: a cross shaft universal hinge, a propeller hub elastic bearing and a variable-pitch hinge; the universal hinge comprises a cross shaft, a universal hinge lock yoke, a first connecting piece, a second connecting piece and a three fork piece of the hub shell; the rotor hub elastic bearing is used for being fixedly arranged on the rotor hub shell three-fork piece, and is positioned above the cross shaft; the variable-pitch hinge is used for being arranged on three support arms of the three fork members of the hub shell of the cross shaft universal hinge. The cross shaft universal hinged hub disclosed by the invention is particularly a semi-hinged hub configuration, can cover the requirements of an aircraft with a larger take-off weight level, and can improve the service life and reliability of the aircraft.

Description

Cross-axle universal hinged hub for tiltrotor aircraft and working method thereof

Technical Field

The invention belongs to the technical field of tilting rotor aircrafts, and particularly relates to a cross-shaft universal hinged hub for a tilting rotor aircraft and a working method thereof.

Background

With the steady expansion and opening of the domestic low-altitude airspace, the vertical take-off and landing aircraft takes a development opportunity period, and the small and medium-sized tilting rotor aircraft with the excellent characteristics of short-distance take-off and landing, quick cruising, high-efficiency air transportation and the like presents competitive situations of competitive development. Tiltrotors, as an advanced rotor configuration, together with co-axial rotors, constitute two major directions of development for high-speed helicopter rotor configurations.

The existing small and medium-sized tiltrotor aircraft mostly adopt a flapping rigid hub (illustratively, a non-hinged hub configuration), the structure is relatively simple, the blades are rigidly connected to the hub, the flapping and flapping movements can only be realized by means of elastic deformation of the blades, and the geometric nonlinear coupling is serious. In addition, once the maximum takeoff weight is increased, the hub bears complex and periodically-changed hub force and moment, so that the problem of dynamic instability of the rotor system can be caused, the maneuvering efficiency is influenced, and the service life of the aircraft is not long, the reliability is poor and the maximum takeoff weight is limited.

Disclosure of Invention

The present invention is directed to a cross-shaft universal-joint hub for tiltrotor aircraft and a method of operating the same that address one or more of the above-identified problems. The cross shaft universal hinged hub provided by the invention is a semi-hinged hub configuration, can cover the requirements of aircraft with larger take-off weight level, and improves the service life and reliability of the aircraft.

In order to achieve the above purpose, the invention adopts the following technical scheme:

In a first aspect of the invention, there is provided a spider universal hinge hub for a tiltrotor aircraft, comprising: a cross shaft universal hinge, a propeller hub elastic bearing and a variable-pitch hinge; wherein,

The universal hinge of the cross shaft comprises a cross shaft, a universal hinge lock yoke, a first connecting piece, a second connecting piece and a three fork piece of the hub shell; the cross shaft comprises a first shaft and a second shaft which are vertically staggered, the first shaft is used for being connected with the three fork pieces of the hub shell through the first connecting piece, and the second shaft is used for being connected with the universal hinge lock yoke through the second connecting piece; the universal hinged lock yoke is used for being mounted on the rotor shaft, and is provided with a mounting interface used for being connected with a torque arm of the control mechanism; bearings are arranged between the first shaft and the first connecting piece and between the second shaft and the second connecting piece, and the universal hinged yoke is arranged below the cross shaft;

The rotor hub elastic bearing is used for being fixedly arranged on the rotor hub shell three-fork piece, and is positioned above the cross shaft;

The variable-pitch hinge is used for being arranged on three support arms of the three fork members of the hub shell of the cross shaft universal hinge.

A further improvement of the present invention is that,

Bearings arranged between the first shaft and the first connecting piece and between the second shaft and the second connecting piece are needle bearings;

The needle roller bearing is used for being installed at the shaft end of the cross shaft.

A further improvement of the present invention is that,

The paddle hub elastic bearing comprises an upper mounting plate, a lower mounting plate and an elastic bearing; wherein,

The elastic bearing is used for being arranged between the upper mounting piece and the lower mounting piece; the hub elastic bearing is used for being fixedly installed on the three fork pieces of the hub shell through the lower installation piece.

A further improvement of the present invention is that,

The elastic bearing is a single, serial or parallel elastic bearing group or an elastic rubber group.

A further improvement of the present invention is that it further comprises: the fairing support is used for being installed on the rotor shaft and is located above the propeller hub elastic bearing.

A further improvement of the present invention is that,

The universal hinged lock yoke is used for being installed and assembled on the rotor shaft, specifically, the universal hinged lock yoke is used for being connected with the rotor shaft through a flat key or a spline and is fixed through a lock nut or a stop washer.

A further improvement of the present invention is that,

The pitch-varying hinge comprises a pitch-varying shell, a pitch-varying rocker arm, a thrust bearing and a deep groove ball bearing; wherein,

The outer side end part of the variable-pitch shell is provided with a first installation part for blade connection, and the inner side end part of the variable-pitch shell is fixedly connected with the variable-pitch rocker arm;

the distance-changing rocker arm is provided with a second installation part which is used for being connected with a distance-changing pull rod of the control mechanism;

the variable-pitch shell is used for being sleeved outside the support arm of the three fork piece of the hub shell through a thrust bearing and a deep groove ball bearing.

According to a second aspect of the present invention, there is provided a working method of the universal joint pin and universal hinge hub according to the first aspect of the present invention, including:

the center of the hub of the universal hinged hub of the cross shaft is connected with the rotor shaft; torque output by the power system is transmitted to the universal hinge hub of the cross shaft through the rotor shaft, so that the universal hinge hub of the cross shaft rotates around the center of the hub, free rotation of the blades around the center of the hub is realized, and aerodynamic lift force is generated.

According to a third aspect of the present invention, there is provided a working method of the universal-joint-pin-universal-joint hub according to the first aspect of the present invention, including:

The center of the hub of the universal hinged hub of the cross shaft is connected with the rotor shaft; the cross shaft rotates around bearings arranged between the first shaft and the first connecting piece and between the second shaft and the second connecting piece, so that the plane of the propeller hub is inclined and drives the rotating plane of the propeller blade to incline, and the propeller blade swings around the center of the propeller hub.

According to a fourth aspect of the present invention, there is provided a working method of the universal-joint-pin-universal-joint hub according to the first aspect of the present invention, including:

The center of the hub of the universal hinged hub of the cross shaft is connected with the rotor shaft; the pitch-changing rocker arm is pulled by the pitch-changing pull rod of the control mechanism and drives the pitch-changing shell and the blade to rotate, so that the blade pitch change is realized.

Compared with the prior art, the invention has the following beneficial effects:

Aiming at the problems that the maximum take-off weight is limited, the service life of the propeller hub is short, and the flying stability and the maneuvering performance are poor in three flying modes due to the adoption of a flapping rigid propeller hub configuration of a medium and small-sized tilting rotor aircraft, the invention discloses a cross-shaft universal hinged propeller hub for the tilting rotor aircraft, which comprises a cross-shaft universal hinge with a variable angle power transmission characteristic, a variable pitch hinge capable of realizing the variable pitch of a blade and a propeller hub elastic bearing capable of improving the flying maneuvering performance, the requirements of the aircraft with a larger take-off weight level can be covered, the service life and the reliability of the aircraft can be improved, and the transmission of a rotor system in three modes of a helicopter, tilting transition and a fixed wing can be realized, so that the medium and small-sized tilting rotor aircraft is effectively supported for scientific research and test flight. Further illustratively, the center waving of the hub can be realized through the universal joint of the cross shaft, so that the blade can swing freely in a wide range, the helicopter has good maneuverability and flexibility, and the flight stability and the maneuvering performance are improved; according to the invention, the periodic waving moment is provided through the elastic bearing of the hub, the overlarge waving of the blade is restrained, and the control efficacy of the helicopter can be improved.

Drawings

In order to more clearly illustrate the technical solutions of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below; it will be apparent to those of ordinary skill in the art that the drawings in the following description are of some embodiments of the invention and that other drawings may be derived from them without undue effort.

FIG. 1 is a schematic view of the overall structure of a cross-shaft universal-joint hub for a tiltrotor aircraft, in accordance with embodiments of the present invention;

FIG. 2 is a schematic cross-sectional view of a cross-shaft gimbal hub for a tiltrotor aircraft according to embodiments of the present invention;

FIG. 3 is a schematic view of a cross-shaft structure according to an embodiment of the present invention;

reference numerals in the drawings are explained as follows,

1. Universal hinge of cross axle; 2. a hub elastic bearing; 3. a variable-pitch hinge; 4. a rotor shaft; 5. a cowling bracket; 6. a cross shaft; 7. needle roller bearings; 8. a first connector; 9. a universal hinged yoke; 10. a hub housing trifurcate member; 11. and a second connecting piece.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention; it will be apparent that the described embodiments are some, but not all, embodiments of the invention. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the disclosed embodiments, are within the scope of the present invention. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Referring to fig. 1 to 3, in an embodiment of the present invention, a cross-shaft universal hinge hub for a small and medium-sized tiltrotor aircraft is provided, comprising: a cross shaft universal joint 1, a propeller hub elastic bearing 2 and a variable pitch joint 3; wherein,

The cross shaft universal joint 1 is used for realizing center joint of the propeller hub; the cross shaft universal joint 1 comprises a cross shaft 6, a universal joint locking yoke 9, a first connecting piece 8, a second connecting piece 11 and a hub shell three-fork piece 10; wherein the cross shaft 6 comprises a first shaft and a second shaft which are vertically staggered, the first shaft is used for being connected with the three fork pieces 10 of the hub shell through the first connecting piece 8, and the second shaft is used for being connected with the universal hinged lock yoke 9 through the second connecting piece 11; the universal hinged yoke 9 is used for being mounted on the rotor shaft 4, and the universal hinged yoke 9 is provided with a mounting interface used for being connected with a torque arm of the operating mechanism; bearings are arranged between the first shaft and the first connecting piece 8 and between the second shaft and the second connecting piece 11, and the universal hinged yoke 9 is arranged below the cross shaft 6; illustratively, the cross universal joint 1 is used for being installed on the upper part of the rotor shaft 4, is connected with the rotor shaft 4 through a universal joint locking yoke 9 and is provided with a locking round nut and a stop washer for fixing;

The hub elastic bearing 2 is fixedly arranged on the hub shell three fork piece 10, and the hub elastic bearing 2 is positioned above the cross shaft 6; illustratively, the hub elastomeric bearing 2 includes an upper mounting plate, a lower mounting plate, and an elastomeric bearing; the rotor hub elastic bearing 2 is arranged at the upper part of a rotor hub shell three-fork piece 10 of the cross shaft universal joint 1 and is connected with the rotor hub shell three-fork piece 10 through a lower mounting piece by screws;

The variable-pitch hinge 3 is used for being arranged on three support arms of a hub shell three-fork piece 10 of the cross shaft universal hinge 1; illustratively, the pitch hinge 3 comprises a pitch housing, a pitch horn, a thrust bearing, and a deep groove ball bearing; the variable-pitch hinge 3 is used for being arranged on three support arms of the three fork members 10 of the hub shell of the cross shaft universal hinge 1, and the variable-pitch hinge 3 can be fixed on the three fork members 10 of the hub shell through locking round nuts and stop washers.

The universal hinge propeller hub comprises the universal hinge with the variable-angle power transmission characteristic, the variable-pitch hinge capable of realizing variable pitch of the blades and the propeller hub elastic bearing capable of improving flight maneuvering performance, the requirements of the aircraft with a larger take-off weight level can be covered, the service life and the reliability of the aircraft are improved, the transmission of a rotor system in three modes of a helicopter, tilting transition and a fixed wing can be realized, and the small-and-medium-sized tilting rotor aircraft is effectively supported for scientific research test flight.

In one embodiment of the present invention, the cross shaft 6 includes two shafts that are vertically staggered, wherein one shaft is connected to the three fork members 10 of the hub shell through the first connecting member 8, and the other shaft is connected to the universal hinged yoke 9 through the second connecting member 11; the universal-joint yoke 9 is configured to be mounted on the rotor shaft 4 (further specifically illustratively, the universal-joint yoke 9 may be flat-keyed/splined to the rotor shaft 4 and locked by a round nut and a stop washer, transmitting the power torque of the rotor shaft 4 to the hub and blades via the universal-joint yoke 9, the spider 6, the pitch horn 3); the lower end of the universal hinged yoke 9 is provided with an installation interface connected with a torque arm bolt of the operating mechanism so as to drive the operating mechanism to synchronously rotate; the bearing adopts a needle bearing 7 and is used for being assembled at the shaft end of the cross shaft 6, and the cross shaft 6 rotates around the needle bearing 7 to drive the hub to swing up and down around the center, namely the center is hinged. Further, by way of further specific example, the first connector 8 is adapted to be fixedly connected to the hub shell three fork 10 by means of bolts; the second connecting piece 11 is used for fixedly connecting with the universal hinged yoke 9 through bolts.

In a specific embodiment of the present invention, the hub elastic bearing 2 includes, but is not limited to, an elastic bearing and a rubber material, where the elastic bearing may be a single, serial or parallel elastic bearing group/elastic rubber group, and the elastic bearing group/elastic rubber group may be designed according to the required stiffness of the hub spring swing, and is used for being fixedly connected with the hub shell three-fork member 10 through a bolt, for transmitting the hub bending moment and inhibiting the excessive swing of the blade. Further illustratively, the hub elastomeric bearing 2 is bolted to the cross-shaft gimbal 1 for synchronous rotation, the hub elastomeric bearing 2 being configured to provide cyclic flapping moment and inhibit excessive flapping of the blades to enhance helicopter maneuvering efficiency.

In one embodiment of the present invention, the pitch hinge 3 includes a pitch housing, a pitch swing arm, a thrust bearing, a deep groove ball bearing, and necessary bearing bushings, locking round nuts, stop washers, etc., for achieving pitch change of the blade and for transferring blade load to the cross universal hinge 1 for balancing; the outer side end part of the pitch-changing shell is provided with a connecting part which is used for connecting the blades by adopting a double-lug bolt and transmitting the blade load (such as a waving bending moment, a shimmy bending moment, a hinge moment, a waving shearing force, a shimmy shearing force and a centrifugal force), the inner side end part of the pitch-changing shell is connected with the pitch-changing rocker arm by adopting a bolt, and the deep groove ball bearing and the thrust bearing are wrapped in the shell; the pitch-changing shell transmits shearing force, waving bending moment and shimmy bending moment to the deep groove ball bearing, centrifugal force to the thrust bearing and hinge moment to the pitch-changing rocker arm. In the embodiment of the invention, the pitch-changing rocker arm is connected with the pitch-changing shell in a bolt connection mode, centrifugal force is transmitted to the thrust bearing, and hinge moment is transmitted to an operating mechanism of the aircraft through double ears of the rocker arm; the thrust bearing is used for bearing centrifugal force generated by rotation of the blade; the deep groove ball bearing is used for bearing a waving bending moment, a shimmy bending moment and a shearing force generated by rotation of the blade. Further illustratively, the pitch hinge 3 includes a pitch housing, a pitch horn, a thrust bearing, and a deep groove ball bearing; the outer side end part of the variable-pitch shell is provided with a first installation part for blade connection, and the inner side end part of the variable-pitch shell is fixedly connected with the variable-pitch rocker arm; the distance-changing rocker arm is provided with a second installation part which is used for being connected with a distance-changing pull rod of the control mechanism; the variable-pitch housing is used for being sleeved outside the support arm of the hub housing three-fork member 10 through a thrust bearing and a deep groove ball bearing. The deep groove ball bearings A, the thrust bearings and the deep groove ball bearings B are sequentially mounted on the support arms of the three-fork piece in a transition fit manner, wear-resistant bearing bushings are arranged between the bearings, and the end parts of the support arms are fixedly limited by adopting stop washers and round nuts; the variable-pitch shell is sleeved outside the support arm of the three fork piece and is mounted in transition fit with the outer ring of the bearing; inner end of variable-pitch shell the pitch-variable rocker arm is connected through bolts; the pitch-changing rocker arm is connected with a pitch-changing pull rod of the operating mechanism through a double-lug installation part by bolts, and transmits the hinge moment to the operating mechanism.

In one embodiment of the present invention, the cross-shaft universal-joint hub further comprises: a fairing bracket 5, said fairing bracket 5 being adapted to be mounted on the rotor shaft 4, said fairing bracket 5 being located above said hub elastomeric bearing 2.

Principle description of the technical scheme of the embodiment of the invention:

The universal hinge hub of the cross shaft is used for being arranged at the upper part of a rotor shaft of the nacelle at two sides of the tiltrotor aircraft; the center of the propeller hub is connected with a rotor shaft flat key/spline through a universal hinged lock yoke and is fixed by a locking round nut and a stop washer;

the outer end of the propeller hub is in single-double-lug bolt connection with the propeller blade through a variable-pitch shell (illustratively, the upper part of the rotor shaft is in spline/parallel key connection with a universal hinged yoke, the lower part of the rotor shaft is in spline connection with a power system, and the output torque of the power system is transmitted to the universal hinged propeller hub of the cross shaft through the rotation of the rotor shaft so as to drive the propeller blade to rotate and generate aerodynamic lift force);

The universal hinge of the cross shaft can realize free up-and-down waving of the blade, but the blade cannot be unlimited and must be freely waving within the design range; according to the invention, the propeller hub elastic bearing is connected with the cross shaft through the universal hinge, so that on one hand, the free waving angle of the blade is limited (the blade is limited through the propeller hub elastic bearing), and on the other hand, the control efficiency is improved (the propeller hub elastic bearing is not provided, the control moment of the universal hinge propeller hub is almost zero, and the universal hinge can be better controlled by applying the propeller hub elastic bearing).

The term is used for the sake of explanation:

1) Semi-articulated hub configuration refers to a hub configuration intermediate between a fully articulated hub configuration and a non-articulated hub configuration, with manoeuvrability intermediate between fully articulated and non-articulated. The universal hinged propeller hub configuration belongs to a semi-hinged propeller hub configuration, and a central swing hinge, a variable-pitch hinge and a non-shimmy hinge exist; due to the design of the universal hinged hub, the blades can swing freely in a wide range, so that the helicopter has good maneuverability and flexibility, the flight stability can be improved, and the helicopter is an essential key component of the three-arm tilting rotor aircraft.

2) The full-hinged hub structure is a hub structure with a swing hinge, a shimmy hinge and a variable-pitch hinge, and the three hinges correspond to three different hinge structures, so that the structure is relatively complex, and the maintenance and overhaul workload is large. At the same time, this complex structure results in a relatively low fatigue life of the hub, many internal bearings of the hinge structure, requiring fine lubrication to prevent wear and failure.

3) The non-hinged hub structure is a hub structure without a flap hinge and a shimmy hinge, the structure is relatively simple, the blade is rigidly connected to the hub, shimmy and flap motion can only be realized by means of elastic deformation of the blade, and the geometrical nonlinear coupling is serious, so that the problem of instability of the rotor system is caused, and the control efficiency is influenced. Because the swing hinge and the shimmy hinge are not limited, the control of the non-hinged hub is more direct and effective, and the control efficiency is high.

4) Small and medium-sized tiltrotor aircraft (illustratively, according to the sixty-two regulations of unmanned aircraft flight management published by the national institute of Care and the Central military Commission of 2023, a small unmanned aircraft refers to an aircraft with a maximum takeoff weight of not more than 25kg, and a medium-sized unmanned aircraft refers to an aircraft with a maximum takeoff weight of not more than 150 kg).

At present, medium-sized and small-sized tiltrotor aircraft basically adopts a rigid rotor hub structure, and the rotor hub bears complex rotor hub force, moment and other periodic variable loads, so that the service life of the aircraft is not long, the reliability is poor, and the maximum takeoff weight is limited; in addition, the constant-speed transmission of the aircraft in three flight modes of a helicopter, tilting transition and a fixed wing cannot be realized, so that the rotor wing/wing structure dynamics problem is caused, and the aircraft with a larger weight level is difficult to develop. The invention is mainly oriented to small and medium-sized unmanned aerial vehicles with the maximum takeoff weight of 25 kg-150 kg (illustratively, the hub load of the miniature and light unmanned aerial vehicle is not large, and a universal hinge type hub with a relatively complex structure is not necessary and rarely adopted); in the technical scheme provided by the embodiment of the invention, the transmission of the load of the propeller hub is realized by adopting three main functional components of the universal joint pin, the propeller hub elastic bearing and the variable-pitch hinge, and the technical scheme has the characteristics of large transmission torque, small transmission rotating speed fluctuation, compact structure, few parts, small overall size and lighter weight, and is suitable for being used on medium-and small-sized tilting rotor aircrafts.

In the embodiment of the invention, a working method of the universal hinge hub of the cross shaft is specifically provided, and the working method comprises the following conditions:

The hub rotates about a hub center, comprising: the output torque of the power system is transmitted to the universal hinge hub of the cross shaft through the rotor shaft, so that the hub rotates around the hub center, the blades can freely rotate around the hub center, and aerodynamic lift force is generated;

Blade center flapping motion, comprising: the cross shaft rotates around the two groups of needle roller bearings, so that the plane of the hub is inclined, the rotation plane of the blade is driven to be inclined, and the blade swings around the center of the hub; illustratively, the blades can flap up and down freely in a certain range through the flap motion of the blades, so that the blades cannot be subjected to excessive constraint or resistance, and the positions and angles of the blades can be automatically adjusted according to the change of the flight state so as to maintain the optimal flight effect; in addition, by means of the center hinged structure of the hub, partial load generated in the high-speed rotation and waving process of the blade can be offset internally, and stability and safety of the rotor wing system are maintained;

The total pitch-varying/cyclic pitch-varying motion of the blade comprises: the pitch-variable rocker arm is pulled by the control mechanism to drive the pitch-variable shell and the blades to rotate, so that the blade pitch change is realized, the attitude and the flight direction of the aircraft are further controlled, and the aircraft is suitable for different flight states and wind conditions.

In summary, the embodiment of the invention provides a cross-shaft universal hinged hub for a small and medium-sized tilting rotor aircraft and a working method thereof, which can support key technical attack, production development and scientific research test flight of the small and medium-sized tilting rotor aircraft; further specifically illustratively, the cross-shaft universal hinge structure can transmit the power torque of the rotor shaft to realize the central hinge of the hub; the universal hinge of the cross shaft, the structure of the variable pitch hinge and the elastic bearing of the propeller hub are integrally designed, and the characteristic of compact structure is that the load of the propeller hub is obviously improved (the propeller hub provided by the invention is particularly and illustratively improved in load, particularly the center swing hinge type propeller hub provided by the invention is zero in swing moment, and the blade swing of the existing rigid propeller hub is realized by virtue of the elastic deformation of the blade, so that the device has the defects of larger blade load, larger propeller hub load, lower service life and heavier weight), clear force transmission route and lighter weight, and meets the requirements of small and medium-sized tilting rotor aircrafts.

Finally, it should be noted that: the above embodiments are only for illustrating the technical aspects of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the above embodiments, it should be understood by those of ordinary skill in the art that: modifications and equivalents may be made to the specific embodiments of the invention without departing from the spirit and scope of the invention, which is intended to be covered by the claims.

Claims (10)

1. A cross-shaft universal-joint hub for a tiltrotor aircraft, comprising: the universal joint comprises a cross shaft universal joint (1), a propeller hub elastic bearing (2) and a variable pitch joint (3); wherein,

The universal hinge (1) comprises a cross shaft (6), a universal hinge lock yoke (9), a first connecting piece (8), a second connecting piece (11) and a hub shell three-fork piece (10); the cross shaft (6) comprises a first shaft and a second shaft which are vertically staggered, wherein the first shaft is used for being connected with the three fork pieces (10) of the hub shell through the first connecting piece (8), and the second shaft is used for being connected with the universal hinged yoke (9) through the second connecting piece (11); the universal hinged yoke (9) is used for being mounted on the rotor shaft (4), and the universal hinged yoke (9) is provided with a mounting interface used for being connected with a torque arm of the operating mechanism; bearings are arranged between the first shaft and the first connecting piece (8) and between the second shaft and the second connecting piece (11), and the universal hinge yoke (9) is arranged below the cross shaft (6);

The rotor hub elastic bearing (2) is used for being fixedly arranged on the rotor hub shell three-fork piece (10), and the rotor hub elastic bearing (2) is positioned above the cross shaft (6);

the variable-pitch hinge (3) is used for being arranged on three support arms of a three-fork piece (10) of a hub shell of the cross shaft universal hinge (1).

2. A cross-shaft gimbal hub for a tiltrotor aircraft as recited in claim 1,

Bearings arranged between the first shaft and the first connecting piece (8) and between the second shaft and the second connecting piece (11) are needle bearings (7);

the needle bearing (7) is used for being mounted at the shaft end of the cross shaft (6).

3. A cross-shaft gimbal hub for a tiltrotor aircraft as recited in claim 1,

The paddle hub elastic bearing (2) comprises an upper mounting plate, a lower mounting plate and an elastic bearing; wherein,

The elastic bearing is used for being arranged between the upper mounting piece and the lower mounting piece; the hub elastic bearing (2) is fixedly arranged on the hub shell three-fork piece (10) through the lower mounting piece.

4. A cross-shaft gimbal hub for a tiltrotor aircraft as recited in claim 3,

The elastic bearing is a single, serial or parallel elastic bearing group or an elastic rubber group.

5. The cross-shaft gimbal hub for a tiltrotor aircraft according to claim 1, further comprising: the rotor hub comprises a fairing support (5), wherein the fairing support (5) is used for being installed on a rotor shaft (4), and the fairing support (5) is located above the rotor hub elastic bearing (2).

6. A cross-shaft gimbal hub for a tiltrotor aircraft as recited in claim 1,

The universal hinged yoke (9) is used for being installed and assembled on the rotor shaft (4), specifically, the universal hinged yoke (9) is used for being connected with the rotor shaft (4) through a flat key or a spline and is fixed through a lock nut or a stop washer.

7. A cross-shaft gimbal hub for a tiltrotor aircraft as recited in claim 1,

The pitch-variable hinge (3) comprises a pitch-variable shell, a pitch-variable rocker arm, a thrust bearing and a deep groove ball bearing; wherein,

The outer side end part of the variable-pitch shell is provided with a first installation part for blade connection, and the inner side end part of the variable-pitch shell is fixedly connected with the variable-pitch rocker arm;

the distance-changing rocker arm is provided with a second installation part which is used for being connected with a distance-changing pull rod of the control mechanism;

The variable-pitch shell is used for being sleeved outside the support arm of the three fork piece (10) of the hub shell through a thrust bearing and a deep groove ball bearing.

8. A method of operating a cross-shaft universal-joint hub as defined in claim 1, comprising:

The center of the hub of the universal joint cross (1) is connected with the rotor shaft (4); torque output by the power system is transmitted to a hub of the universal joint cross (1) through the rotor shaft (4), so that the hub of the universal joint cross (1) rotates around the center of the hub, free rotation of the blades around the center of the hub is realized, and aerodynamic lift force is generated.

9. A method of operating a cross-shaft universal-joint hub as defined in claim 1, comprising:

The center of the hub of the universal joint cross (1) is connected with the rotor shaft (4); the cross shaft (6) rotates around bearings arranged between the first shaft and the first connecting piece (8) and between the second shaft and the second connecting piece (11), so that the plane of the propeller hub is inclined and drives the rotating plane of the propeller blade to incline, and the propeller blade swings around the center of the propeller hub.

10. A method of operating a cross-shaft universal-joint hub as defined in claim 1, comprising:

the center of the hub of the universal joint cross (1) is connected with the rotor shaft (4); the pitch-changing rocker arm is pulled by the pitch-changing pull rod of the control mechanism and drives the pitch-changing shell and the blade to rotate, so that the blade pitch change is realized.