End stop mechanism for tilt rotor nacelle actuator, actuator and end stop method

Abstract

The invention provides a tail end stopping mechanism for a tilting rotor wing nacelle actuator, the actuator and a tail end stopping method. The tail end stopping mechanism comprises a thrust elastic bearing, a stopping end cover, a thrust needle roller bearing and an end locking ring. The thrust elastic bearing is arranged between the thrust needle roller bearing and the stop end cover; the stop mechanism is fixed in the shaft or the hole through the end locking ring; when the lead screw nut moves to the tail end, the lead screw nut extrudes the stop end cover or the thrust needle roller bearing, axial and rotational deformation of the thrust elastic bearing is caused, motion kinetic energy is absorbed, impact loads are buffered, the lead screw nut is mechanically limited through the limiting ring, the stroke of the lead screw nut is controlled, and the service life of the lead screw nut is prolonged. On the basis that the locking and limiting functions of an actuator structure are met, the actuator can be effectively prevented from being locked in the motion conversion process, and compared with a traditional stop dog, the stop dog is more compact in structure and more convenient and rapid to maintain, and a series of products can be conveniently formed.

Description

[Technical Field]

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) technology, and in particular to an end-of-life stop mechanism, actuator, and end-of-life stop method for a tiltrotor nacelle actuator. [Background Technology]

[0002] The actuator is used to control the rotation of the tiltrotor nacelle around the tilt hinge, enabling the tiltrotor to dynamically switch between helicopter and fixed-wing flight modes. To limit the nacelle's tilt range, a stop mechanism is required for the actuator. The actuator mainly consists of an external lead screw and nut drive motor, an intermediate lead screw and nut drive motor, an external lead screw and nut, an intermediate lead screw and nut, an internal lead screw, an intermediate lead screw and nut stop mechanism, an external lead screw and nut stop mechanism, a nacelle support joint, and a wing support joint.

[0003] The actuator is position-controlled and achieves end-effector stop via a flight control computer. When the motor drives one stage to reach its relative travel limit, the second-stage lead screw rotates and performs further axial movement. However, because the intermediate and outer lead screw nuts are floating, they stop or start rotating at each transition. This motion transition is accompanied by the stopping impact or starting / unlocking of the floating lead screw nut and the inner lead screw. Therefore, while limiting the actuator's range of motion, to avoid the impact force and locking phenomenon when the actuator stops at the end, the end-effector stop mechanism needs to bear the axial actuation load and absorb the kinetic energy of the moving unit through elastic deformation, as well as provide starting / unlocking force.

[0004] The core technological challenge facing the end-stop mechanism of a tiltrotor nacelle's dual-layer actuator lies in achieving precise and reliable motion control in complex flight environments. This challenge manifests itself in several aspects: First, the actuator needs to maintain stable performance in two distinct flight modes—vertical takeoff and landing (VTOL) and fixed-wing—requiring the stop mechanism to possess strong adaptability, buffering capacity, and load-bearing capacity. Second, frequent mode switching generates severe impact loads; effectively absorbing this impact energy without compromising structural integrity is crucial. Third, under high-speed rotation, the stop mechanism is prone to locking up, which can lead to control failure and serious safety hazards. Furthermore, the actuator's motion accuracy directly affects the accuracy of nacelle attitude adjustment; ensuring the motion accuracy of the lead screw and nut in complex mechanical environments is also a challenging issue. Finally, the harsh working environment requires the stop mechanism to have excellent sealing and durability to resist corrosion from external factors such as dust and oil. These interconnected problems constitute a complex systemic technical challenge, which is of great significance for improving the overall performance and reliability of tiltrotor aircraft.

[0005] Therefore, it is necessary to study an end-stop mechanism, actuator, and end-stop method for tilt rotor nacelles to address the shortcomings of the prior art and to solve or mitigate one or more of the aforementioned problems. [Summary of the Invention]

[0006] In view of this, the present invention provides an end-stop mechanism, actuator, and end-stop method for a tiltrotor nacelle actuator. While satisfying the actuator's structural stop and limit function, it can effectively prevent the actuator from locking up during motion transition. Compared with traditional stoppers, it has higher axial load capacity and fatigue resistance. It adopts a modular design, which makes the structure more compact, easier and faster to maintain, and facilitates the formation of a series of products.

[0007] On one hand, the present invention provides an end-stop mechanism for a tiltrotor nacelle actuator, the end-stop mechanism being installed at the moving end of a lead screw nut in the actuator, the end-stop mechanism comprising a thrust elastic bearing, a stop end cap, a thrust needle roller bearing, and an end locking ring;

[0008] The thrust elastic bearing is positioned between the thrust needle roller bearing and the stop end cap;

[0009] The stop mechanism is fixed inside the shaft or hole by an end locking ring;

[0010] When the lead screw nut moves to its end, it presses against the stop end cap or the thrust needle roller bearing, causing the thrust elastic bearing to undergo axial and rotational deformation, absorbing the kinetic energy of the motion and buffering the impact load. A limit ring is set to mechanically limit the lead screw nut and control its stroke.

[0011] In addition to the aspects described above and any possible implementation, a further implementation is provided in which, when the end locking ring secures the stop mechanism within the shaft, the shaft mounting configuration is for the protruding end of the intermediate lead screw nut.

[0012] In addition to the aspects described above and any possible implementation, a further implementation is provided in which, when the end locking ring fixes the stop mechanism in the hole, the in-hole mounting configuration is for the retraction end of the intermediate lead screw nut or the extension end of the outer lead screw nut.

[0013] In addition to the aspects and any possible implementations described above, a further implementation is provided, wherein the limiting ring includes an inner limiting ring and an outer limiting ring, wherein;

[0014] The lead screw nut in the shaft mounting configuration is mechanically limited by the limiting inner ring.

[0015] The lead screw nut in the hole installation configuration is mechanically limited by the limiting outer ring.

[0016] In addition to the aspects described above and any possible implementations, a further implementation is provided in which the stop end cap contacts the limit ring to limit the travel of the lead screw nut.

[0017] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the stop end cap is provided with a slot for radially limiting the thrust elastic bearing.

[0018] In addition to the aspects described above and any possible implementations, a further implementation is provided in which the end stop mechanism further includes a bushing, the bushing comprising an inner bushing and an outer bushing, wherein,

[0019] The shaft mounting type of sealing is achieved by the groove connection between the outer bushing and the stop end cover;

[0020] The sealing of the hole-mounted type is achieved by the groove connection between the inner bushing and the stop end cover.

[0021] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the end stop mechanism further includes a sealing ring, which is an O-ring, to seal the gap between the bushing and the thrust needle roller bearing.

[0022] In addition to the aspects and any possible implementations described above, a further implementation is provided in which the thrust elastic bearing comprises a laminated structure consisting of a sequentially arranged end-face metal layer, a rubber laminate, and a metal laminate.

[0023] The rubber laminate absorbs the axial kinetic energy of the lead screw nut through axial deformation;

[0024] The rubber laminate absorbs the rotational kinetic energy of the lead screw nut through rotational deformation;

[0025] Laminated structures achieve a buffered motion state by bearing axial loads and torsional moments.

[0026] In accordance with the aspects and any possible implementations described above, a method for end-of-arm paving of a tiltrotor nacelle actuator is further provided, implemented by the aforementioned end-of-arm paving mechanism, the method comprising the following steps:

[0027] S1: Obtain the motion state of the actuator, wherein the motion state includes the extension or retraction motion of the lead screw nut;

[0028] S2: The movement of the lead screw nut is limited by a stop mechanism, which includes a thrust elastic bearing and a stop end cap;

[0029] S3: The axial and rotational deformation of the thrust elastic bearing absorbs the kinetic energy of the lead screw nut and buffers the impact load.

[0030] S4: Energy is stored through the deformation of the thrust elastic bearing to provide starting and unlocking force;

[0031] S5: The movement stroke of the lead screw nut is mechanically limited by the limiting ring to complete the end stop.

[0032] In accordance with the aspects described above and any possible implementation, an actuator is further provided, the actuator including the aforementioned end stop mechanism, the actuator further including a lead screw nut, a control logic circuit, and a drive motor, the lead screw nut including an intermediate lead screw nut and an outer lead screw nut, the end stop mechanism being installed at the moving end of the lead screw nut, the actuator adjusting the motion control logic of the intermediate lead screw nut and the outer lead screw nut according to the position of the stop mechanism, the control logic circuit realizing two-stage independent actuation through the drive motor to obtain the precise motion path of the lead screw nut.

[0033] Compared with the prior art, the present invention can achieve the following technical effects:

[0034] This invention addresses the requirements of limiting the range of motion of the lead screw nut, buffering impact loads, and preventing lock-up. It designs a structure comprising a thrust elastic bearing, a stop end cap, a thrust needle roller bearing, and a limiting ring. A metal-rubber composite laminated elastic structure is used as the core component of the thrust elastic bearing, which buffers impact loads through axial deformation and stores energy through rotational deformation to provide the unlocking driving force. The thrust needle roller bearing releases rotational kinetic energy, reducing structural torsion. The limiting ring provides mechanical restraint and ensures safe movement. Dust and oil prevention are achieved through a sealing ring combined with a bushing, and the bearing is secured to the end of the lead screw with a locking ring. This invention adjusts the nut motion control logic to achieve two-stage independent actuation, obtaining a precise motion path. It exhibits excellent buffering, unlocking, and load-bearing performance in both vertical takeoff and landing (VTOL) and fixed-wing modes, effectively solving the key technical problem of end-cap stoppage in tiltrotor nacelle actuators.

[0035] Of course, any product implementing this invention does not necessarily need to achieve all of the technical effects described above at the same time. [Attached Image Description]

[0036] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1This is a cross-sectional view (retracted state) of the mounting structure of the stop mechanism provided in one embodiment of the present invention;

[0038] Figure 2 This is a cross-sectional view of the intermediate lead screw nut stop mechanism provided in one embodiment of the present invention;

[0039] Figure 3 This is a cross-sectional view of the external lead screw and nut stop mechanism provided in one embodiment of the present invention;

[0040] Figure 4 This is a cross-sectional view of a thrust elastic bearing provided in one embodiment of the present invention;

[0041] Figure 5 This is an assembly diagram of an actuator mechanism provided in one embodiment of the present invention;

[0042] Figure 6 This is a schematic diagram of the tilt control structure of a tilt rotor nacelle (vertical take-off and landing mode) provided in one embodiment of the present invention;

[0043] Figure 7 This is a schematic diagram of a tilt rotor nacelle tilt control structure (fixed wing mode) provided in one embodiment of the present invention.

[0044] In the figure:

[0045] Figure 1 Stopping mechanism a, stopping mechanism b, stopping mechanism c, locking ring d, limit block e, locking ring f, locking ring g, and inner shaft of intermediate lead screw nut h;

[0046] Figure 2 1. Shaft end stop cover; 2. Thrust elastic bearing; 3. Limiting inner ring; 4. Outer shaft sleeve; 5. O-ring seal; 6. Thrust needle roller bearing.

[0047] Figure 3 7. Hole end stop cap, 8. Limiting outer ring, 9. Thrust elastic bearing, 10. Inner bushing, 11. Thrust needle roller bearing, 12. O-ring seal.

[0048] Figure 4 : End face metal layer 13, rubber laminate 14, metal laminate 15;

[0049] Figure 5 Internal lead screw j, intermediate lead screw nut k, external lead screw nut l, wing support joint m, nacelle support joint n, drive motor p, drive motor q;

[0050] Figures 6-7 13. Wing 14. Actuator 15. Winglet 16. Nacelle 16.

Detailed Implementation Methods

[0051] To better understand the technical solution of the present invention, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0052] It should be understood that the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0053] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0054] The present invention provides an end-stop mechanism for a tiltrotor nacelle actuator. The end-stop mechanism is installed at the moving end of the lead screw nut in the actuator. The end-stop mechanism includes a thrust elastic bearing, a stop end cap, a thrust needle roller bearing, and an end locking ring.

[0055] The thrust elastic bearing is positioned between the thrust needle roller bearing and the stop end cap;

[0056] The stop mechanism is fixed inside the shaft or hole by an end locking ring;

[0057] When the lead screw nut moves to its end, it presses against the stop end cap or the thrust needle roller bearing, causing the thrust elastic bearing to undergo axial and rotational deformation, absorbing the kinetic energy of the motion and buffering the impact load. A limit ring is set to mechanically limit the lead screw nut and control its stroke.

[0058] When the end locking ring fixes the stop mechanism inside the shaft, the shaft mounting configuration is used for the end of the intermediate lead screw nut in the extension direction.

[0059] When the end locking ring fixes the stop mechanism in the hole, the in-hole installation form is used for the retraction end of the intermediate lead screw nut or the extension end of the outer lead screw nut.

[0060] The limiting ring includes an inner limiting ring and an outer limiting ring, wherein;

[0061] The lead screw nut in the shaft mounting configuration is mechanically limited by the limiting inner ring.

[0062] The lead screw nut in the hole installation configuration is mechanically limited by the limiting outer ring.

[0063] The stop end cap contacts the limit ring to limit the travel of the lead screw nut.

[0064] The stop end cover is provided with a hole or groove, which is used to radially limit the thrust elastic bearing.

[0065] The end stop mechanism further includes a bushing, which comprises an inner bushing and an outer bushing, wherein...

[0066] The shaft mounting type of sealing is achieved by the groove connection between the outer bushing and the stop end cover;

[0067] The sealing of the hole-mounted type is achieved by the groove connection between the inner bushing and the stop end cover.

[0068] The end stop mechanism also includes a sealing ring, which is an O-ring, to seal the gap between the bushing and the thrust needle roller bearing.

[0069] The thrust elastic bearing is a laminated structure consisting of an end-face metal layer, a rubber laminate, and a metal laminate arranged sequentially.

[0070] The rubber laminate absorbs the axial kinetic energy of the lead screw nut through axial deformation;

[0071] The rubber laminate absorbs the rotational kinetic energy of the lead screw nut through rotational deformation;

[0072] Laminated structures achieve a buffered motion state by bearing axial loads and torsional moments.

[0073] The present invention also provides a method for end-of-flight braking of a tiltrotor nacelle actuator, which is achieved by the aforementioned end-of-flight braking mechanism. The end-of-flight braking method includes the following steps:

[0074] S1: Obtain the motion state of the actuator, wherein the motion state includes the extension or retraction motion of the lead screw nut;

[0075] S2: The movement of the lead screw nut is limited by a stop mechanism, which includes a thrust elastic bearing and a stop end cap.

[0076] S3: The axial and rotational deformation of the thrust elastic bearing absorbs the kinetic energy of the lead screw nut and buffers the impact load.

[0077] S4: Energy is stored through the deformation of the thrust elastic bearing to provide starting and unlocking force;

[0078] S5: The movement stroke of the lead screw nut is mechanically limited by the limiting ring to complete the end stop.

[0079] Furthermore, the above steps S1-S5 are refined as follows:

[0080] S101. Obtain the end-stop requirements of the tilt rotor nacelle double-layer actuator. The requirements include limiting the range of motion of the lead screw nut, buffering impact loads, and preventing locking. Determine that the stop mechanism must have high axial load capacity and rotation unlocking function.

[0081] The requirements for end-effector stop of the tiltrotor nacelle's dual-layer actuator are obtained. Descriptions related to limiting the range of motion of the lead screw and nut, buffering impact loads, and preventing lock-up are extracted to obtain a preliminary set of technical requirements. Based on this preliminary information set, the functional descriptions of the stop mechanism in the pre-designed scheme are analyzed to identify specific requirements for limiting the extension and retraction of the lead screw and nut, buffering axial impacts, and providing a rotary unlocking function, thus determining the detailed parameters of the technical objectives. Using these detailed parameters, the structural composition of the stop mechanism in the pre-designed scheme is analyzed, and characteristic data of the metal-rubber composite laminated elastic structure, thrust elastic bearing, and axial thrust needle roller bearing are extracted to obtain the performance information of the core stop element. If the performance information of the core stop element meets the requirements for high axial load capacity and rotary unlocking function, the compressive stiffness and torsional stiffness data of the metal-rubber composite laminated elastic structure are correlated with the axial deformation and rotational deformation data of the thrust elastic bearing to determine whether the mechanical performance of the stop mechanism meets the technical objectives. Based on the mechanical performance assessment, the installation method description of the stop mechanism in the preset scheme is extracted. The locking ring fixing schemes for shaft mounting and in-hole mounting, as well as the radial limiting design of the stop end cover, are analyzed to obtain the assembly constraints of the stop mechanism. Through these constraints, the sealing design of the sealing ring between the thrust elastic bearing and the stop end cover in the preset scheme is analyzed. Combined with the slot fixing method of the inner / outer bushings, the sealing and stability performance of the stop mechanism during motion transition is determined. If the sealing and stability performance meets the technical objectives, the process of kinetic energy absorption and impact load buffering is simulated based on the description of the screw nut end face pressing against the stop end cover or thrust needle roller bearing in the preset scheme, obtaining the dynamic response data of the stop mechanism. Through the dynamic response data, the energy storage mechanism of the axial and rotational deformation of the thrust elastic bearing in the preset scheme is analyzed, and the release process of the starting and unlocking force is calculated to determine the function of the stop mechanism in preventing locking. Based on the determination of the starting and unlocking force, the description of the modular design in the preset scheme is integrated, and the characteristics of the stop mechanism's compact structure and ease of maintenance are extracted to obtain the technical implementation scheme for a series of products.

[0082] For example, the description of the movement range limitation of the lead screw nut is extracted from the preset scheme. The functional requirements of the external lead screw nut l being extended and stopped by the stop mechanism b and retracted by the stop mechanism c are identified, and a constraint condition with a movement stroke limitation parameter of ±50mm is established. The characteristics of the metal-rubber composite laminated elastic structure are analyzed, and its axial compressive stiffness reaches 500N / mm and its torsional stiffness is less than 10N·m / rad, meeting the design requirements of high axial load and low rotational resistance. The working condition of the lead screw nut end impacting the stop end cover at a speed of 0.5m / s is simulated by finite element analysis, and the dynamic response of the thrust elastic bearing absorbing 120J of kinetic energy when it generates 15mm axial deformation and 8° torsional deformation is calculated. The contact stress of the thrust needle roller bearing under a 5000N axial load is calculated using Hertz contact theory, and the sealing ring can maintain a sealing pressure of 20MPa under a compression of 0.1mm is verified. Based on the law of conservation of energy, the formula for starting and unlocking force is derived as F = Kθ·Δθ / r (where Kθ is the torsional stiffness, Δθ is the torsion angle, and r is the lever arm). When Δθ = 5°, the unlocking force is measured to be 45N. According to the modular assembly parameters, a standardized dimensional chain with an outer diameter of Φ80mm and a length of 120mm is generated for the stop mechanism, and the groove tolerance of the matching locking rings f and g is H7 / g6.

[0083] S102. Based on the end-stopping requirements, design a stopping mechanism structure. The structure includes a thrust elastic bearing, a stopping end cover, a thrust needle roller bearing, and a limiting inner ring or a limiting outer ring. The thrust elastic bearing enables axial and rotational deformation, absorbing the kinetic energy of the screw nut movement.

[0084] Obtain the structural data of the external lead screw and nut stop mechanism described in the preset scheme, and extract the installation positions and connection methods of the thrust elastic bearing, stop end cover, thrust needle roller bearing, and limiting inner or outer ring to obtain the core component parameters of the stop mechanism. Based on the extracted core component parameters, analyze the hole-groove connection method between the thrust elastic bearing and the stop end cover, and determine the radial limiting structure data of the thrust elastic bearing. By analyzing the radial limiting structure data of the thrust elastic bearing, calculate the deformation capacity of the thrust elastic bearing in the axial and rotational directions to obtain the deformation parameters of the thrust elastic bearing. Obtain the motion data of the lead screw nut at its extension and retraction ends, and combine it with the deformation parameters of the thrust elastic bearing to calculate the kinetic energy absorption when the end face of the lead screw nut presses against the stop end cover or thrust needle roller bearing to determine the kinetic energy absorption data. Based on the kinetic energy absorption data, simulate the energy stored by the thrust elastic bearing during axial and rotational deformation to obtain the energy storage parameters. By analyzing the energy storage parameters, analyze the ability of the thrust elastic bearing to provide starting and unlocking force to determine the unlocking force value. If the unlocking force value meets the preset axial load capacity threshold, the locking data of the stop end cover and the inner / outer bushing is extracted. Combined with the sealing structure of the sealing ring, the overall sealing performance of the stop mechanism is judged. Based on the overall sealing performance of the stop mechanism, the fixing method of the end locking ring in the shaft or hole is analyzed to determine the installation stability data of the stop mechanism. Through the installation stability data of the stop mechanism, the collaborative working ability of the thrust elastic bearing, the stop end cover, the thrust needle roller bearing, and the limiting inner or outer ring during the stopping process at the end of the screw nut is verified, and the technical implementation verification results of the stop mechanism are obtained.

[0085] For example, structural data of the external lead screw nut stop mechanism is extracted from the preset scheme. It is identified that the thrust elastic bearing is installed between the end cap of the stop and the thrust needle roller bearing, achieving radial limiting through the slot. Its installation position is recorded as the end of the middle lead screw nut in the retraction direction and the end of the external lead screw nut in the extension direction. Core component parameters include a thrust elastic bearing thickness of 5mm, a stop end cap hole diameter of 30mm, and a thrust needle roller bearing outer diameter of 32mm. The slot connection method is analyzed, and the slot width is measured to be 2mm and the depth 1.5mm. The radial displacement limit of the thrust elastic bearing is calculated to be ±0.3mm, and the allowable axial deformation range is 0.5mm to 1.2mm. Combining the end speed of the lead screw nut (0.2m / s) and its mass of 1.5kg, the impact kinetic energy of 0.03J is calculated using the kinetic energy formula E=0.5mv². Simulating the energy storage of 0.025J when the thrust elastic bearing compresses and deforms by 1mm, the remaining energy of 0.005J is absorbed through rotational deformation. If the axial load threshold is set to 500N, the unlocking force is calculated to be 450N based on the energy storage parameters. After meeting the requirements, the data of the stop end cover groove is retrieved. The groove width is 3mm, the fit tolerance is H7 / g6, the sealing ring is made of nitrile rubber with a compression rate of 20%, and the calculated sealing pressure is 0.8MPa. The end locking ring is made of 304 stainless steel with a yield strength of 205MPa. The von Mises stress distribution in the shaft hole is simulated, and the peak stress is 120MPa, which is lower than the material limit. The deformation of the thrust elastic bearing and the sealing pressure are linearly related when the mechanism works together. The fitting coefficient R is [missing value]. 2 =0.98.

[0086] S103. A metal-rubber composite laminated elastic structure is used as the core component of the thrust elastic bearing. The component consists of an end-face metal layer, a rubber laminate, and a metal laminate. The laminated structure is formed through a vulcanization process to bear axial loads and torsional torques.

[0087] Obtain the structural information of the thrust elastic bearing described in the preset scheme, extract the composition characteristics of the end-face metal layer, rubber laminate, and metal laminate, and determine its laminated structure design parameters. Based on the extracted laminated structure design parameters, analyze the technical requirements of the vulcanization process to obtain the combination of process parameters for temperature, pressure, and time during vulcanization. By analyzing the vulcanization process parameters, simulate the bonding strength between the metal layer and the rubber laminate to determine whether the laminated structure meets the requirements for bearing axial load and torsional moment. If the laminated structure meets the bearing requirements, obtain the installation position information of the thrust elastic bearing in the stop mechanism to determine its relative positional relationship with the thrust needle roller bearing and the stop end cover. Based on the installation position relationship of the thrust elastic bearing, calculate its axial compression deformation when the lead screw nut extends or retracts, and obtain the corresponding deformation data. Through the axial compression deformation data, simulate the energy absorption characteristics of the thrust elastic bearing during the deformation process to determine its buffering capacity for the kinetic energy of the lead screw nut. Obtain the rotational deformation characteristics of the thrust elastic bearing, analyze the interlaminar shear deformation of the rubber laminate under torsional moment, and determine whether it provides sufficient starting and unlocking force. If the rotational deformation meets the starting and unlocking force requirements, the axial and rotational deformation data are integrated to generate comprehensive performance parameters of the thrust elastic bearing in the stop mechanism. Based on the comprehensive performance parameters, the stop and buffer functions of the thrust elastic bearing in the tilt rotor nacelle actuator are verified, and the results of the achievement verification of the technical objectives are obtained.

[0088] For example, the structural parameters of the thrust elastic bearing are extracted from a preset scheme. The end face metal layer is made of No. 45 steel with a thickness of 1.5 mm. The rubber laminate is made of nitrile rubber with a single layer thickness of 0.8 mm, and the metal laminate is made of 304 stainless steel with a thickness of 0.5 mm. The laminated structure is designed with 10 layers of rubber and 9 layers of metal arranged alternately. According to the vulcanization process requirements, the vulcanization temperature is set to 150℃, the pressure to 12 MPa, and the time to 30 minutes. Finite element analysis simulates that the interlayer bonding strength after vulcanization reaches 15 MPa. ANSYS is used to calculate the stress distribution of the laminated structure under an axial load of 50 kN. The maximum stress occurs at the edge of the metal laminate, which is 320 MPa, lower than the material yield strength. The thrust elastic bearing is installed between the stop end cover and the thrust needle roller bearing. The radial clearance is designed to be 0.1 mm. The axial compression at the end contact of the lead screw nut is analyzed using SolidWorks motion simulation. The deformation measured under the maximum impact load is 2.3 mm. A hyperelastic constitutive model of the rubber was established, and the energy absorbed during deformation was calculated to be 18 J, corresponding to the kinetic energy of the lead screw nut at a speed of 0.5 m / s. The shear angle of the rubber laminate under a torsional torque of 5 Nm was measured to be 12° using a torque sensor, meeting the starting and unlocking force requirements. Based on the combined results of ABAQUS multiphysics coupling analysis, the fatigue life of the thrust elastic bearing under combined axial and rotational deformation exceeds 100,000 cycles, meeting the actuator's usage requirements.

[0089] S104. Through the axial deformation of the thrust elastic bearing, the impact load of the lead screw nut in the extended or retracted state is buffered to obtain the buffered motion state. At the same time, the energy stored by the rotational deformation is used to provide driving force for the start-up and unlocking of the lead screw nut.

[0090] By detecting the axial deformation data of the thrust elastic bearing, the impact load parameters of the lead screw nut in its extended or retracted state are obtained, and the initial impact load is quantified. Based on the quantified initial impact load, the proportion of kinetic energy absorbed by the thrust elastic bearing during axial deformation is calculated, and the motion state parameters after buffering are determined. Using the buffered motion state parameters, the residual kinetic energy distribution of the lead screw nut at stop is analyzed, and real-time energy conversion data is obtained. Based on the real-time energy conversion data, the energy value stored by the thrust elastic bearing during rotational deformation is recorded, and the energy reserve of rotational deformation is obtained. Using the energy reserve of rotational deformation, the driving force required for the lead screw nut to start and unlock is simulated, and the theoretical value of the unlocking driving force is determined. If the theoretical value exceeds the preset driving force range, the energy reserve is recalculated by adjusting the rotational displacement parameters of the thrust elastic bearing, and optimized driving force data is obtained. Based on the optimized driving force data and the rotational motion release characteristics of the thrust needle roller bearing, the motion stability during unlocking is analyzed, and stability evaluation results are obtained. Using the stability evaluation results, the motion trajectory parameters of the lead screw nut during start-up and unlocking are calibrated, and the final unlocking motion control scheme is determined. Based on the final unlocking motion control scheme, the collaborative working status of the thrust elastic bearing and the thrust needle roller bearing is monitored in real time to obtain dynamic feedback data on the motion conversion of the lead screw nut.

[0091] For example, when detecting the axial deformation data of a thrust elastic bearing, a strain sensor is used to measure the deformation. For instance, when the axial load reaches 500N, a deformation displacement of 0.2mm is recorded. The impact load parameters are then calculated using the material's elastic modulus, yielding a quantified impact force of 300N·s. Based on this quantified value, the kinetic energy formula E = 0.5mv is applied. 2The proportion of kinetic energy absorbed by the thrust elastic bearing is calculated. If the speed of the lead screw nut is 0.5 m / s and its mass is 2 kg, the kinetic energy is reduced by 60% after buffering, and the motion parameters show a remaining speed of 0.32 m / s. When analyzing the distribution of residual kinetic energy, the energy conversion region is divided through finite element simulation. If axial deformation absorbs 70% of the kinetic energy and the remaining 30% is distributed in the rotation direction, the real-time data shows that the torsional energy accounts for 30%. When recording the rotational deformation energy, a torque sensor is used to measure the torque value of 2 N·m corresponding to a torsion angle of 5°. Combined with the bearing stiffness coefficient of 0.4 N·m / °, the stored energy is calculated to be 5 J. When simulating the unlocking driving force requirement, the minimum unlocking force is set to 10 N according to the Coulomb friction model. If the theoretical calculated value is 12 N, the requirement is met; if the calculated value is 8 N, the rotational displacement parameter is adjusted to 7°, and the energy reserve is recalculated to increase to 7 J, so that the driving force reaches 11 N. Combining the friction coefficient of the thrust needle roller bearing (0.05) and a rotational speed of 100 rpm, the unlocking stability was analyzed. If the axial deviation was less than 0.1 mm and the angular velocity fluctuation was less than 5%, the stability was deemed satisfactory. During motion trajectory calibration, a PID controller was used to adjust the motor output, with a position error tolerance set at ±0.05 mm. The final control scheme output pulse frequency was 200 Hz. During real-time monitoring of the coordinated status, bearing speed difference data was collected via an encoder. If the synchronization error between axial and rotational motion was less than 2%, the dynamic feedback data was marked as normal.

[0092] S105. For the buffered motion state, a thrust needle roller bearing is configured between the thrust elastic bearing and the stop end cover. The rotational kinetic energy of the lead screw nut is released through the thrust needle roller bearing, the rotational motion is restored, and the structural torsion is reduced.

[0093] By analyzing the axial elastic deformation data of the thrust elastic bearing, the absorption of kinetic energy of the external lead screw nut is obtained, yielding the initial state parameters for buffering the impact load. Based on these initial state parameters, the rotational displacement of the thrust elastic bearing is calculated to determine the degree of absorption of the rotational kinetic energy of the external lead screw nut. The rotational displacement data is processed using the rotational motion release mechanism of the thrust needle roller bearing to determine if the rotational kinetic energy has reached the release threshold. If the rotational kinetic energy reaches the release threshold, the dynamic parameters for rotational motion recovery are obtained using the positional relationship data between the thrust needle roller bearing and the stop end cap. Based on these dynamic parameters, the friction coefficient of the contact surface of the thrust needle roller bearing is adjusted to determine the stability index of the rotational motion release. Using the stability index, the mechanical transmission data between the thrust elastic bearing and the thrust needle roller bearing is analyzed to obtain a quantitative result of the reduction in structural torsion. Based on the quantitative result, combined with the radial limiting data of the stop end cap at the bore end, the positional offset value of the thrust needle roller bearing in the buffered motion state is calculated. Using the positional offset value, the motion correlation data between the thrust elastic bearing and the intermediate lead screw nut is processed to determine if there is any additional accumulation of rotational kinetic energy. If there is additional accumulated rotational kinetic energy, the motion state parameters are adjusted through the secondary release mechanism of the thrust needle roller bearing to obtain the final rotational motion recovery data.

[0094] For example, the deformation curve of the thrust elastic bearing under axial load is simulated using finite element analysis software. When the external lead screw nut is subjected to an impact force of 500N, the bearing compression reaches 0.2mm, and the stiffness coefficient of 120N / mm is extracted as the initial state parameter. Based on this parameter, a rotational kinetic energy absorption model is established. When the input speed is 300rpm, the thrust elastic bearing is calculated to generate a 15° angular displacement, corresponding to the absorption of 3.5J of rotational kinetic energy. Hertz contact theory is used to analyze the raceway contact stress of the thrust needle roller bearing. When the angular displacement exceeds 10°, the release condition is triggered. The position mapping relationship is established using the geometric parameter of 0.05mm bearing clearance. Based on the axial vibration amplitude of 0.1mm obtained from dynamic monitoring, the surface roughness Ra of the needle rollers is adjusted to 0.2μm to maintain a friction coefficient of 0.008, so that the rotational fluctuation is controlled within ±2rpm. A torque transmission matrix analysis is established. When the force transmission deviation between the thrust elastic bearing and the needle roller bearing is less than 5%, the optimized result of a structural torsion angle of 0.5° is output. Based on the 8mm groove width limit data of the end cap of the hole stop, the radial offset of the needle roller bearing is calculated to be 0.03mm. The residual vibration frequency of the intermediate lead screw nut at 2Hz is identified by Fourier transform. If the residual rotational kinetic energy exceeds 0.3J, the secondary release procedure is activated, and the preload of the needle roller assembly is adjusted to 50N, ultimately reducing the rotational imbalance to below 0.8%.

[0095] S106. A limiting inner ring or a limiting outer ring is provided in the stopping mechanism. The limiting inner ring is used for shaft mounting and the limiting outer ring is used for hole mounting. The limiting structure realizes the mechanical limitation of the stroke of the lead screw nut and ensures the safety of movement.

[0096] By analyzing the design data of the stop mechanism, the installation position information of the inner and outer limiting rings is extracted, yielding the structural parameters for the shaft mounting form of the inner limiting ring and the hole mounting form of the outer limiting ring. Based on the extracted structural parameters, the mechanical limiting effect of the inner limiting ring between the shaft end cap and the thrust needle roller bearing is simulated to determine its travel limit range at the end of the lead screw nut's retraction direction. By simulating the installation state of the outer limiting ring between the hole end cap and the thrust needle roller bearing, its mechanical limiting effect on the end of the lead screw nut's extension direction is calculated, obtaining the corresponding travel boundary data. The travel boundary data is matched with the lead screw nut's motion trajectory model to analyze the contact point position between the lead screw nut and the limiting structure during extension and retraction, determining whether the contact point meets the design limit requirements. If the contact point position exceeds the design limit range, the slot fixing parameters of the inner and outer limiting rings are adjusted, and the contact point data is recalculated to obtain the corrected limit boundary value. If the contact point position meets the design limit requirements, the final installation parameters of the inner and outer limit rings are recorded to determine their spatial positioning data within the stop mechanism. Using this spatial positioning data, combined with the axial and rotational deformation characteristics of the thrust elastic bearing, the force distribution when the end face of the lead screw nut presses against the stop end cap or thrust needle roller bearing is simulated, obtaining dynamic response data for buffering impact loads. Based on the dynamic response data, the synergistic effect of the limit structure and the thrust elastic bearing is analyzed, the mechanical limiting stability of the lead screw nut at the end of its stroke is calculated, and the safety parameters of the overall stop mechanism are determined. These safety parameters are integrated with the system motion control algorithm to generate digital control logic for limiting the lead screw nut's stroke, resulting in the final mechanical limit and motion safety assurance scheme.

[0097] For example, when analyzing the design data of the stop mechanism, the shaft installation parameters of the inner limiting ring are extracted as inner diameter Φ20mm and outer diameter Φ30mm, and the hole installation parameters of the outer limiting ring are inner diameter Φ40mm and outer diameter Φ50mm. Assembly relationships are established using 3D modeling software. When simulating the action of the inner limiting ring between the shaft end stop cap and the thrust needle roller bearing, the travel limit in the retraction direction of the lead screw nut is set to ±5mm, and the maximum axial force it can withstand is calculated to be 500N using finite element analysis. For the outer limiting ring, in the installation simulation between the hole end stop cap and the thrust needle roller bearing, the travel limit in the extension direction is set to ±8mm, and its impact load resistance is obtained as 800N through dynamic simulation. The travel boundary data is input into the motion trajectory model, and the coordinates of the contact point between the lead screw nut and the limiting structure are calculated using a MATLAB algorithm. If the contact point is detected to exceed the ±5mm or ±8mm range, the slot fixing parameters are automatically adjusted to within the tolerance of ±0.1mm. After meeting the limit requirements, the axial positioning tolerance of the inner limit ring is recorded as ±0.05mm, and the radial runout of the outer limit ring is ≤0.02mm. Combining the deformation curve of the thrust elastic bearing (stiffness coefficient 50N / mm), the dynamic response under pressure at the end face of the lead screw nut is simulated, and the output impact load attenuation rate is 80%. Based on the dynamic response data, the cooperative stability of the limit structure and the bearing is calculated, yielding a safety factor ≥2.5. Finally, the safety parameters are embedded into the PID control algorithm to generate digital limit logic, outputting pulse signals to control the lead screw motor to decelerate to 0.1m / s at the end of its stroke.

[0098] S107. A sealing ring is used in combination with an inner or outer bushing to provide a dustproof and oil-proof sealing treatment for the stop mechanism. The sealing ring is installed between the stop end cover and the thrust needle roller bearing to obtain a sealed stop mechanism structure.

[0099] By analyzing the content of the preset scheme, relevant descriptions regarding the connection between the sealing ring and the inner or outer bushing in the stop mechanism are extracted to obtain the basic data of the sealing structure. Based on the extracted basic data, the specific position information of the sealing ring installed between the stop end cover and the thrust needle roller bearing is identified, and the arrangement of the sealing ring is determined. Using digital modeling technology, the groove connection structure of the sealing ring, inner bushing, and stop end cover is simulated in three dimensions to obtain the spatial constraints of the sealing ring in the assembly. Through simulation results, the contact surface characteristics between the sealing ring and the thrust needle roller bearing are analyzed to determine the coverage range of the sealing ring in dustproof and oilproof functions. If the contact surface characteristics indicate insufficient coverage, optimization is performed by adjusting the size parameters or material properties of the sealing ring to obtain an improved sealing structure design. Based on the optimized design data, the fit relationship between the sealing ring and the inner and outer bushings is mechanically simulated to determine the stability of the sealing ring under stress. Through the mechanical simulation results, the dynamic sealing effect between the sealing ring and the thrust needle roller bearing during the operation of the stop mechanism is evaluated to obtain quantitative indicators of sealing performance. If the quantitative indicators meet the dustproof and oil-proof sealing requirements, then the sealing structure data is integrated into the overall design of the stop mechanism to obtain a complete sealed stop mechanism structure. Using the integrated structural data, a complete digital assembly model of the stop mechanism is generated, determining the final sealing treatment scheme and the matching relationship between components.

[0100] For example, analyzing the description in the preset scheme that "O-ring 12 cooperates with the inner hole sidewall to achieve dust and oil prevention sealing of the stop mechanism", the groove connection method between the sealing ring and the inner bushing 10 is extracted, and a basic data model of the sealing structure is established, setting the inner diameter of the sealing ring to 20mm and the outer diameter to 22mm. Based on this data, the axial clearance between the sealing ring installed on the hole end stop cover 7 and the thrust needle roller bearing 11 is identified as 1.5mm, and the compression rate of the sealing ring is determined to be 15%. Using SolidWorks parametric modeling, the sealing ring cross-sectional diameter of 2.5mm and Shore hardness of 70HA are input, simulating its deformation of 0.3mm in the groove, and outputting the contact pressure distribution cloud map under spatial constraints. By analyzing the contact surface characteristics through ANSYS, if the contact width between the sealing ring and the thrust needle roller bearing 11 is less than 2mm, the cross-sectional diameter is adjusted to 3mm so that the peak contact pressure reaches 0.8MPa. Based on the optimized model, an axial load of 500 N and a rotational speed of 100 rpm were set in ADAMS, and the simulated dynamic leakage of the sealing ring was less than 0.01 ml / min. If the simulation results showed that the displacement fluctuation of the sealing ring was less than 0.1 mm, the model was imported into the NX assembly and tolerance matching was performed with components such as the limiting outer ring 8 and the thrust elastic bearing 9 to generate a digital assembly model with clearance fit H7 / g6.

[0101] S108. The sealed stop mechanism structure is fixed to the end of the internal lead screw or intermediate lead screw nut by an end locking ring. The locking ring is used for shaft mounting or in-hole mounting to determine the stable position of the stop mechanism in the actuator.

[0102] By analyzing the installation position data of the stopping mechanism in the actuator, the structural parameters of the end holes or shafts of the external lead screw nut and the intermediate lead screw nut are identified to obtain the suitable installation form for the stopping mechanism. Based on the obtained installation form data, it is determined whether the stopping mechanism adopts shaft mounting or in-hole mounting, and the corresponding locking ring fixing scheme is obtained. Using the obtained locking ring fixing scheme, the connection point information between the stopping mechanism and the end of the internal lead screw or intermediate lead screw nut is extracted, and the geometric constraints of the connection points are determined. If the geometric constraints of the connection points meet the design specifications, the installation path data of the locking ring between the stopping mechanism and the end of the lead screw nut is generated, and the radial and axial limit parameters of the locking ring are determined. Based on the generated locking ring installation path data, the assembly process of the stopping mechanism in the actuator is simulated to obtain the positional stability index after assembly. Using the obtained stability index, the force distribution data of the stopping mechanism during motion conversion is analyzed to determine whether there is a risk of positional deviation. If the analysis results show that there is a risk of positional deviation, the fixing parameters of the locking ring are adjusted and the force distribution is recalculated to obtain optimized stability data. Based on the optimized stability data, a collaborative working model of the stop mechanism, thrust elastic bearing, and stop end cap is generated to determine the overall structure's buffering and stopping performance parameters. Using these determined performance parameters, a complete installation and operation data chain for the stop mechanism within the actuator is constructed to obtain the final stable position and operating status information.

[0103] For example, when analyzing the installation position data of the stop mechanism in the actuator, 3D modeling software is used to extract the diameter tolerance of the end holes of the external lead screw nut and the intermediate lead screw nut (±0.02mm), and the surface roughness of the shaft (Ra1.6). The stress distribution for the suitable installation form is calculated using finite element analysis. If the maximum stress is lower than the material yield strength of 345MPa, the installation form is deemed feasible. Based on the installation form data, a locking ring with an inner diameter of 30mm is selected for in-hole installation, and a locking ring with an outer diameter of 25mm is selected for shaft installation. ANSYS simulation verifies that the contact pressure between the locking ring and the lead screw does not exceed 200MPa. When extracting the connection points of the stop mechanism, a topology optimization algorithm is used to identify that the positional error of the M6 ​​threaded hole at the end of the lead screw is ≤0.05mm. If the perpendicularity between the threaded hole axis and the end face of the stop mechanism exceeds the tolerance by 0.1mm, a geometric constraint alarm is triggered. When generating the locking ring installation path, the radial preload of 50 N·m and the axial limiting clearance of 0.3 mm were calculated based on kinematic algorithms. The axial movement after assembly was verified to be <0.1 mm using ADAMS multibody dynamics simulation. When analyzing the motion conversion force, the impact load spectrum at the end of the lead screw nut was collected. If the peak load exceeded 8 kN, the gradient descent algorithm was used to optimize the locking ring fixing parameters, ensuring the compression of the rubber composite laminate structure was controlled within 2 mm ± 0.2 mm. When constructing the collaborative working model, the stiffness coefficient of the thrust needle roller bearing (1200 N / mm) was coupled with the damping characteristics of the metal-rubber composite layer, resulting in an energy absorption efficiency of 92% with a buffer stroke of 3.5 mm. Finally, all parameters were integrated using digital twin technology to output the dynamic stability curve of the stop mechanism under nacelle tilting ±90° conditions.

[0104] S109. Based on the position of the stop mechanism, adjust the motion control logic of the intermediate lead screw nut and the outer lead screw nut. The control logic achieves two-stage independent operation through the drive motor to obtain the precise motion path of the lead screw nut.

[0105] The system acquires real-time position data of stop mechanisms b and c, and detects the axial displacement of the external lead screw nut l and the intermediate lead screw nut k using sensors to obtain the current state of the stop mechanisms. Based on the position data of stop mechanisms b and c, the relative travel distance of the external lead screw nut l and the intermediate lead screw nut k is calculated to determine the movement range of the two-stage lead screw nuts. If the external lead screw nut l approaches the extension limit of stop mechanism b, the flight control computer generates a control signal for the first-stage drive motor to obtain a deceleration command for the external lead screw nut l. If the intermediate lead screw nut k approaches the retraction limit of stop mechanism c, the flight control computer generates a control signal for the second-stage drive motor to obtain a deceleration command for the intermediate lead screw nut k. Based on the deceleration commands of the external lead screw nut l and the intermediate lead screw nut k, the speed and torque of the drive motors are adjusted to obtain the precise movement speed of the two-stage lead screw nuts. Using the axial deformation data of the thrust elastic bearing 2, the axial kinetic energy absorbed by the stop mechanism is calculated to determine the buffer state of the stop mechanism. If the rotational displacement data of the thrust elastic bearing 2 exceeds a preset threshold, the rotational kinetic energy of the internal lead screw j is released through the thrust needle roller bearing 6, resulting in the stopping limit of the intermediate lead screw nut k. Based on the buffer state and stopping limit of the stopping mechanism, the motion control logic of the flight control computer is updated to obtain the optimized motion path of the two-stage lead screw nuts. The flight control computer decomposes the optimized motion path into a control command sequence for the drive motor, obtaining the precise motion trajectories of the external lead screw nut l and the intermediate lead screw nut k.

[0106] For example, Hall effect sensors are used to collect real-time position data of stop mechanisms b and c, with a sampling frequency set to 1kHz. By measuring the axial displacement changes of the external lead screw nut l and the intermediate lead screw nut k, and combining this with the pulse signal fed back from the encoder, the current state of the stop mechanism is determined. Based on the position data and preset stroke thresholds (e.g., the maximum extension stroke of the external lead screw nut l is 120mm, and the maximum retraction stroke of the intermediate lead screw nut k is 80mm), a linear interpolation algorithm is used to calculate the relative motion stroke of the two lead screw nuts, dynamically updating the motion range boundary. When the displacement of the external lead screw nut l reaches 115mm (approaching the extension limit of stop mechanism b), the flight control computer calls the PID control algorithm to generate a PWM speed regulation signal for the first-stage drive motor, and the output duty cycle linearly decreases from 90% to 30%, achieving smooth deceleration of the external lead screw nut l. If the displacement of the intermediate lead screw nut k is less than 5mm (approaching the retraction limit of stop mechanism c), the flight control computer adjusts the current output of the second-stage drive motor through a fuzzy control algorithm, reducing the torque from 10N·m to 2N·m in a stepwise manner. Based on the slope change of the deceleration command, a Kalman filter algorithm is used to correct the speed and torque parameters of the drive motor in real time, keeping the speed error of the two-stage lead screw nuts within ±0.1 mm / s. The axial deformation of the thrust elastic bearing 2 is measured by strain gauges (e.g., a compression of 2.5 mm corresponds to absorbing 15 J of kinetic energy), and the buffer stiffness coefficient is calculated using Hooke's law to determine that the stop mechanism is in a critical buffer state. When the laser gyroscope detects that the rotational displacement angular velocity of the thrust elastic bearing 2 exceeds 50 rad / s, the electromagnetic clutch of the thrust needle bearing 6 is triggered, releasing the accumulated rotational kinetic energy (e.g., angular momentum of 0.8 kg·m² / s) of the internal lead screw j. Based on the buffer stiffness coefficient and angular momentum release data, the flight control computer uses a dynamic programming algorithm to regenerate the motion trajectory, improving the path planning accuracy to ±0.05 mm. Finally, the path coordinates are converted into a stepping pulse sequence (e.g., 2000 pulses / mm) of the drive motor using an inverse kinematics model, driving the external lead screw nut l and the intermediate lead screw nut k to move along a preset trajectory.

[0107] S1010. For the precise motion path, verify the performance of the stop mechanism in vertical take-off and landing mode and fixed-wing mode. The verification includes impact buffering effect, unlocking force provision and axial load capacity, and determine the final stop mechanism design scheme.

[0108] Data extraction was performed on the stop mechanism design scheme described in the preset plan to obtain the stop mechanism configuration information at the ends of the external and intermediate lead screw nuts in the extension and retraction directions, thus obtaining the installation position and functional parameters of the stop mechanism under different motion modes. Based on the extracted stop mechanism configuration information, simulation models of the lead screw nut motion paths in vertical take-off and landing (VTOL) and fixed-wing modes were constructed to determine the contact points and force distribution data between the stop mechanism and the end face of the lead screw nut in both modes. Using the contact point and force distribution data from the simulation model, the impact load values ​​experienced by the stop mechanism in VTOL and fixed-wing modes were calculated to obtain the energy absorption of the thrust elastic bearing in axial and rotational deformation. By analyzing the calculated energy absorption, the buffering effect parameters of the thrust elastic bearing in the two modes were analyzed to determine the degree of impact load mitigation by the stop mechanism. If the buffering effect parameters were lower than a preset threshold, the metal-rubber composite laminate structure parameters of the thrust elastic bearing were adjusted to obtain optimized bearing stiffness and deformation data, and a new buffering effect evaluation result was determined. Based on the optimized buffering effect evaluation results, the ability of the stop mechanism to provide starting and unlocking force in two modes was simulated, and the energy release characteristics of the thrust elastic bearing in axial and rotational deformation were obtained. By analyzing the release characteristic data, the stability of the unlocking force output of the stop mechanism in vertical take-off and landing (VTOL) and fixed-wing modes was determined to see if the unlocking force meets the requirements of motion conversion. If the unlocking force output stability is insufficient, the parameters of the stop end cap and the limiting structure of the thrust needle roller bearing were adjusted in conjunction with the modular design characteristics mentioned in the preset scheme to obtain improved unlocking force output data and judge the final unlocking force performance. Based on the improved buffering effect and unlocking force output data, the axial load-bearing capacity of the stop mechanism in both modes was comprehensively evaluated to obtain the final performance results, and a stop mechanism design scheme suitable for VTOL and fixed-wing modes was determined.

[0109] For example, the configuration information of the stopping mechanism of the external lead screw nut and the intermediate lead screw nut is extracted from the preset scheme, including the installation position of the thrust elastic bearing (the end of the intermediate lead screw nut in the retraction direction and the end of the external lead screw nut in the extension direction) and the fixing method of the end locking ring. When establishing the motion path simulation model, the contact distance between the end face of the lead screw nut and the stop end cover is set to ±5mm. The impact load is calculated by finite element analysis. It is assumed that the maximum axial impact force is 2000N in the vertical take-off and landing mode and 1500N in the fixed wing mode. The energy absorption formula E=0.5kΔx is used. 2(k is the stiffness of the elastic bearing, Δx is the axial deformation) Quantify the buffering effect. If the buffering efficiency is less than 85%, adjust the thickness of the rubber laminate 14 of the metal-rubber composite laminate structure from 2mm to 3mm, recalculate the stiffness k value and increase it by 20%. When simulating the unlocking force, the deformation energy storage formula F=kΔθ / r (Δθ is the torsional deformation angle, r is the bearing radius) is used. If the output force fluctuates by more than ±10%, modify the groove depth of the stop end cover 7 from 1.5mm to 2mm to enhance the limiting stability. Finally, when comprehensively considering the axial load capacity, a weighted evaluation algorithm is used, with 60% weight for the vertical take-off and landing mode and 40% weight for the fixed wing mode to obtain the optimal design scheme.

[0110] The present invention also provides an actuator, which includes the aforementioned end-stop mechanism, and further includes a lead screw nut, a control logic circuit, and a drive motor. The lead screw nut includes an intermediate lead screw nut and an outer lead screw nut. The end-stop mechanism is installed at the moving end of the lead screw nut. The actuator adjusts the motion control logic of the intermediate lead screw nut and the outer lead screw nut according to the position of the end-stop mechanism. The control logic circuit realizes two-stage independent actuation through the drive motor to obtain the precise motion path of the lead screw nut.

[0111] Example 1:

[0112] This invention relates to an elastic stop mechanism at the end of an actuator. Two installation configurations of the stop mechanism are involved: (1) shaft mounting; (2) in-hole mounting. The intermediate lead screw nut stop mechanism is shaft mounted, installed at the end of the internal lead screw in the extension direction, and its components are secured and locked together by an end locking ring. The external lead screw nut stop mechanism is in-hole mounted, installed at the end of the intermediate lead screw nut in the retraction direction and the end of the external lead screw nut in the extension direction, respectively, and locked together by an end locking ring.

[0113] In this invention, a thrust elastic bearing is used as the core stop and buffer component, positioned between the thrust needle roller bearing and the stop end cover. The inner / outer bushings are fixed to the stop end cover via slots, and the thrust elastic bearing is radially limited by the stop end cover's slots. A sealing ring seals the inner / outer bushings and the thrust needle roller bearing. The entire stop mechanism is fixed to the shaft or hole by an end locking ring. When the lead screw nut extends / retracts to its end, the end face of the lead screw nut presses against the stop end cover or the end face of the thrust needle roller bearing, causing axial and rotational deformation of the thrust elastic bearing. This absorbs the kinetic energy of the lead screw nut's movement and buffers impact loads, improving axial load-bearing capacity. Simultaneously, the axial and rotational deformation of the thrust elastic bearing stores energy to provide starting and unlocking force. Mechanical limiting is achieved using inner / outer limiting rings to ensure the safety of the actuation mechanism's stroke. The thrust elastic bearing is used to recover most of the structural torsion caused by the rotational movement of the lead screw nut on the stop mechanism. The modular design of the stop mechanism makes the structure more compact and maintenance more convenient and faster.

[0114] like Figure 1 As shown, the actuator end elastic stop mechanism includes stop mechanism a, stop mechanism b, and stop mechanism c. Stop mechanism a is fixed to the end of the shaft of the inner lead screw j by a locking ring d. The extension movement of the intermediate lead screw nut k is stopped by the limiting contact between stop mechanism a and the inner shaft h of the intermediate lead screw nut. The retraction movement of the intermediate lead screw nut k is stopped by the limiting contact between stop mechanism a and the limiting block e. Stop mechanism b is fixed to the end of the hole of the outer lead screw nut l by a locking ring f. Stop mechanism c is fixed to the end of the hole of the intermediate lead screw nut k by a locking ring g. The extension movement of the outer lead screw nut l is stopped by stop mechanism b, and the retraction movement of the outer lead screw nut l is stopped by stop mechanism c.

[0115] like Figure 2 As shown, the stopping mechanism a consists of a shaft end stop cover 1, a thrust elastic bearing 2, a limiting inner ring 3, an outer bushing 4, an O-ring seal 5, and a thrust needle roller bearing 6. The thrust elastic bearing 2 is installed between the shaft end stop cover 1 and the thrust needle roller bearing 6, connected through a slot in the shaft end stop cover 1 to achieve radial limiting. The outer bushing 4 is connected to the shaft end stop cover 1 through a groove and, in conjunction with the O-ring seal 5 and the internal lead screw j, achieves dust and oil prevention sealing for the stopping mechanism. The limiting inner ring 3 is installed between the shaft end stop cover 1 and the thrust needle roller bearing 6 for mechanical limiting. Through the axial elastic deformation of the thrust elastic bearing 2, the kinetic energy of the intermediate lead screw nut k is absorbed and impact loads are buffered. The rotational displacement of the thrust elastic bearing 2 absorbs the rotational kinetic energy of the internal lead screw j, and the rotational motion is released through the thrust needle roller bearing 6, thereby achieving the stopping restriction of the intermediate lead screw nut k. This device has a simple and compact structure and strong impact resistance.

[0116] 3. Stopping mechanisms b and c adopt the same structural form, consisting of a bore end stop cover 7, a limiting outer ring 8, a thrust elastic bearing 9, an inner bushing 10, a thrust needle roller bearing 11, and an O-ring seal 12. The thrust elastic bearing 9 is installed between the bore end stop cover 7 and the thrust needle roller bearing 11, connected through the slot in the bore end stop cover 7 to achieve radial limiting. The inner bushing 10 is connected to the bore end stop cover 7 through a groove and, in conjunction with the O-ring seal 12, works with the inner bore sidewall to achieve dust and oil prevention sealing of the stopping mechanism. The limiting outer ring 8 is installed between the bore end stop cover 7 and the thrust needle roller bearing 11 for mechanical limiting. Figure 3 As shown, the axial elastic deformation of the thrust elastic bearing 9 absorbs the kinetic energy of the external lead screw nut l and buffers the impact load. The rotational displacement of the thrust elastic bearing 9 absorbs the rotational kinetic energy of the external lead screw nut l, and the rotational motion is released through the thrust needle roller bearing 11, thereby achieving the stopping and limiting of the external lead screw nut l.

[0117] like Figure 4 As shown, the thrust elastic bearing 2 and the thrust elastic bearing 9 are composed of an end face metal layer 13, a rubber laminate 14, and a metal laminate 15. The end face metal layer 13, the metal laminate 15 and the rubber laminate 14 are vulcanized into a laminated structure, which can bear axial load and torsional torque, and buffer the load through axial and rotational deformation.

[0118] like Figure 5 As shown, the actuator mainly consists of an internal lead screw j, an intermediate lead screw nut k, an external lead screw nut l, a wing support joint m, a nacelle support joint n, a drive motor p, and a drive motor q. The lead screw and nut of the actuator can be connected by ball bearings or roller bearings. The actuator operates using two independent control stages: drive motor p drives the internal lead screw j to rotate, achieving linear motion of the intermediate lead screw nut k within the internal lead screw j, thus achieving the first stage of actuator operation; drive motor q drives the intermediate lead screw nut k to rotate, achieving linear motion of the external lead screw nut l within the intermediate lead screw nut k, thus achieving the second stage of actuator operation. The tilt control of the tilt rotor nacelle is achieved through this method. Figure 6 As shown. The tilt control of the tilt rotor nacelle is achieved through the above method. Figure 7 As shown.

[0119] This invention utilizes a metal-rubber composite laminated elastic structure as the core stopping element. Kinetic energy conversion during motion transition is achieved through the axial deformation of the rubber elasticity and the torsional deformation between the rubber layers. To facilitate easy restoration of free configuration, an axial thrust needle roller bearing is installed at the end of the stack. The composite laminated elastic structure possesses high compressive stiffness while maintaining relatively low torsional stiffness. This end-stop mechanism, while fulfilling the stopping and limiting function of the actuator structure, effectively prevents actuator lock-up during motion transition. Compared to traditional stoppers, it has higher axial load-bearing capacity and fatigue resistance. Its modular design makes the structure more compact, maintenance more convenient and quick, and facilitates the development of a series of products.

[0120] The foregoing has provided a detailed description of the end-of-arm stop mechanism, actuator, and end-of-arm stop method for a tiltrotor nacelle actuator provided in the embodiments of this application. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this application; furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

[0121] Certain terms are used in the specification and claims to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The terms "comprising" and "including" used throughout the specification and claims are open-ended and should be interpreted as "comprising / including but not limited to". "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error. The following descriptions in the specification are preferred embodiments for carrying out this application; however, these descriptions are for the purpose of illustrating the general principles of this application and are not intended to limit the scope of this application. The scope of protection of this application shall be determined by the appended claims.

[0122] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a product or system comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a product or system. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the product or system that includes said element.

[0123] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0124] The foregoing description illustrates and describes several preferred embodiments of this application. However, as previously stated, it should be understood that this application is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the application concept described herein through the foregoing teachings or techniques or knowledge in related fields. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of this application should be within the protection scope of the appended claims.

Claims

1. An end-stop mechanism for a tiltrotor nacelle actuator, the end-stop mechanism being installed at the moving end of a lead screw nut in the actuator, characterized in that, The end stop mechanism includes a thrust elastic bearing, a stop end cap, a thrust needle roller bearing, and an end locking ring; The thrust elastic bearing is positioned between the thrust needle roller bearing and the stop end cap; The stop mechanism is fixed inside the shaft or hole by an end locking ring; When the lead screw nut moves to its end, it presses against the stop end cap or the thrust needle roller bearing, causing the thrust elastic bearing to undergo axial and rotational deformation, absorbing the kinetic energy of the motion and buffering the impact load. A limit ring is set to mechanically limit the lead screw nut and control its stroke.

2. The end-stop mechanism according to claim 1, characterized in that, When the end locking ring fixes the stop mechanism inside the shaft, the shaft mounting configuration is used for the end of the intermediate lead screw nut in the extension direction.

3. The end-stop mechanism according to claim 2, characterized in that, When the end locking ring fixes the stop mechanism in the hole, the in-hole installation form is used for the retraction end of the intermediate lead screw nut or the extension end of the outer lead screw nut.

4. The end-stop mechanism according to claim 3, characterized in that, The limiting ring includes an inner limiting ring and an outer limiting ring, wherein; The lead screw nut in the shaft mounting configuration is mechanically limited by the limiting inner ring. The lead screw nut in the hole installation configuration is mechanically limited by the limiting outer ring.

5. The end-stop mechanism according to claim 4, characterized in that, The stop end cover contacts the limiting ring to limit the movement stroke of the lead screw nut. The stop end cover is provided with a hole or groove for radially limiting the thrust elastic bearing.

6. The end-stop mechanism according to claim 5, characterized in that, The end stop mechanism further includes a bushing, which comprises an inner bushing and an outer bushing, wherein... The shaft mounting type of sealing is achieved by the groove connection between the outer bushing and the stop end cover; The sealing of the hole-mounted type is achieved by the groove connection between the inner bushing and the stop end cover.

7. The end-stop mechanism according to claim 1, characterized in that, The end stop mechanism also includes a sealing ring, which is an O-ring, to seal the gap between the bushing and the thrust needle roller bearing.

8. The end-stop mechanism according to claim 1, characterized in that, The thrust elastic bearing is a laminated structure consisting of an end-face metal layer, a rubber laminate, and a metal laminate arranged sequentially. The rubber laminate absorbs the axial kinetic energy of the lead screw nut through axial deformation; The rubber laminate absorbs the rotational kinetic energy of the lead screw nut through rotational deformation; Laminated structures achieve a buffered motion state by bearing axial loads and torsional moments.

9. An actuator, characterized in that, The actuator includes an end-stop mechanism as described in any one of claims 1-8. The actuator also includes a lead screw nut, a control logic circuit, and a drive motor. The lead screw nut includes an intermediate lead screw nut and an outer lead screw nut. The end-stop mechanism is installed at the moving end of the lead screw nut. The actuator adjusts the motion control logic of the intermediate lead screw nut and the outer lead screw nut according to the position of the stop mechanism. The control logic circuit realizes two-stage independent actuation through the drive motor to obtain the precise motion path of the lead screw nut.

10. A method for end-of-arm braking of a tiltrotor nacelle actuator, implemented by the end-of-arm braking mechanism described in any one of claims 1-8, characterized in that, The end-capping method includes the following steps: S1: Obtain the motion state of the actuator, wherein the motion state includes the extension or retraction motion of the lead screw nut; S2: The movement of the lead screw nut is limited by a stop mechanism, which includes a thrust elastic bearing and a stop end cap; S3: The axial and rotational deformation of the thrust elastic bearing absorbs the kinetic energy of the lead screw nut and buffers the impact load. S4: Energy is stored through the deformation of the thrust elastic bearing to provide starting and unlocking force; S5: The movement stroke of the lead screw nut is mechanically limited by the limiting ring to complete the end stop.

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