Mastered elastic dry friction damper and method of use

Abstract

The application discloses a master type elastic support dry friction damper and a use method, and belongs to the technical field of aero-engines. The master type elastic support dry friction damper comprises a static sliding set, a static friction sheet, a dynamic friction sheet, an elastic support, an adjusting assembly, a bearing frame and a damper support wall. The elastic support is installed on a rotor main shaft through a bearing. The dynamic friction sheet is installed on a first end surface of the elastic support. A second end surface of the elastic support and a second end surface of the damper support wall are both connected to the bearing frame. The static sliding set and the adjusting assembly are both arranged between the elastic support and the damper support wall. The static friction sheet is installed on the static sliding set. The static sliding set controls parallel contact of the static friction sheet and the dynamic friction sheet. A driving end of the adjusting assembly is provided with an actuator. Through the design that the static sliding set is connected with the static friction sheet, extremely high radial installation stiffness and extremely low axial movement resistance are realized, and the contradiction of installation stiffness is fundamentally solved.

Description

Technical Field

[0001] This application belongs to the field of aero-engine technology, and specifically relates to a main-controlled missile dry friction damper and its usage method. Background Technology

[0002] In aero-engines, especially turboshaft / turboprop engines, the power turbine rotor typically features a slender shaft and a critical speed for low-order bending modes close to the operating speed. During startup, shutdown, and operation under varying conditions, the rotor needs to cross the critical speed, triggering resonance and generating severe vibrations that seriously threaten safety and lifespan. Traditional passive vibration reduction measures (such as squeeze film dampers) are insufficient to meet the demands of the ever-expanding rotor operating speed range and the complex and variable vibration states. Therefore, vibration control technology capable of actively adjusting parameters to adapt to different modes and speeds has become a research focus. Elastic bearing dry friction dampers (ESDFDs), as a novel active vibration reduction device combining elastic bearing stiffness and dry friction damping, are considered a promising solution due to their relatively simple structure, fast response, low energy consumption, and ease of active control.

[0003] The patent, published under CN112303183A, is titled "A Main Control Type Spindle-Side Dry Friction Damper for Aero Engines." Its typical structure includes an elastic support, dynamic friction plates, static friction plates, a piezoelectric ceramic actuator, a force transmission casing, a preload adjusting bolt, a damper mounting sleeve, a static friction plate retaining ring, a static friction plate spring, a static friction plate spring retaining ring, a bearing inner bushing locking nut, a bearing inner bushing, a bearing outer ring locking nut, and a bearing. The damper unit is coaxially fixed to the flange of the elastic support via the force transmission casing. The static friction plate spring within the damper unit improves radial stiffness and ensures parallelism between the dynamic and static friction plates.

[0004] In existing technologies, static friction plates are mostly integrally fitted with a large-sized stationary cylindrical surface with clearance. This leads to two contradictions: first, to ensure smooth axial sliding, clearance must be maintained, sacrificing radial stiffness; second, large-sized precision clearance fits are difficult and costly to manufacture, and assembly errors can easily cause axial tilting, leading to sliding jamming. Although there are improved solutions using a single large-sized linear bearing, this brings problems such as limited bearing selection, large space occupation, and increased weight. Summary of the Invention

[0005] To address the aforementioned issues, this application provides a master-controlled elastic dry friction damper, comprising a static sliding assembly, static friction plates, dynamic friction plates, an elastic support, an adjustment assembly, a load-bearing frame, and a damper support wall. The elastic support is mounted on the rotor main shaft via a bearing; the dynamic friction plate is mounted on the first end face of the elastic support. The second end face of the elastic support and the second end face of the damper support wall are both connected to the load-bearing frame; Both the static sliding assembly and the adjusting assembly are disposed between the elastic support and the damper support wall; the static friction plate is mounted on the static sliding assembly; the static sliding assembly controls the static friction plate to be in parallel contact with the dynamic friction plate; the driving end of the adjusting assembly is provided with an actuator.

[0006] Furthermore, the static friction assembly includes a fixed plate, a sliding cylinder, a linear bearing, an elastic element, and a push rod; the first ends of the multiple sliding cylinders are connected to the static friction plate, and the second ends of the sliding cylinders are connected to the fixed plate; the linear bearing is sleeved on the outer wall of the sliding cylinder; a groove is formed in the first end of the sliding cylinder, and the elastic element is installed in the groove; the first end of the elastic element is connected to the push rod, and the second end of the elastic element is connected to the groove; the push rod contacts the dynamic friction plate.

[0007] Furthermore, the static friction plate includes a static plate one and a static plate two; the static plate one is connected to the static plate two, and the static plate one is in contact with the dynamic friction plate; the static plate two is connected to the output point of the actuator.

[0008] Furthermore, the adjustment assembly includes a locking nut, an adjusting bolt, and a wave spring; the first end of the adjusting bolt contacts the actuator, the second end of the adjusting bolt passes through the fixing plate, and the wave spring is sleeved on the adjusting bolt; the locking nut is threadedly engaged with the adjusting bolt.

[0009] Furthermore, an installation cylinder is provided between the elastic support and the damper support wall, and the first end of the installation cylinder is fixedly connected to the damper support wall; the actuator and the static sliding assembly are integrated inside the installation cylinder.

[0010] Furthermore, the linear bearing and the mounting cylinder have a small interference fit.

[0011] Furthermore, chip removal holes are provided on the friction surface of the moving friction plate.

[0012] Furthermore, the elastic element is a return spring.

[0013] Furthermore, the actuator is a piezoelectric ceramic actuator.

[0014] This application provides a method for using a master-controlled spring-loaded dry friction damper, based on the aforementioned master-controlled spring-loaded dry friction damper, comprising: The dry friction dampers are assembled sequentially. The adjustment components are then adjusted so that the static sliding assembly moves axially to the point where the static friction plate and the dynamic friction plate make microscopic contact. When the actuator is not powered on, the force of the static sliding block keeps the dynamic friction plate and the static friction plate slightly separated. When rotor vibration needs to be controlled, the control system applies a control voltage to the actuator based on the vibration signal. The actuator pushes the stationary friction plate to press the moving friction plate together; After the control requirement ends, the actuator voltage is withdrawn, and the static slider returns to its initial state under the action of the static slider group.

[0015] Compared with the prior art, this application has the following advantages: 1. This application achieves extremely high radial installation stiffness and extremely low axial motion resistance through the design of connecting the static sliding assembly and the static friction plate, fundamentally solving the contradiction of installation stiffness; through the adjustable components, it ensures that the dynamic and static friction plates are in a preset critical contact state after assembly, eliminating uncontrollable passive damping and providing a repeatable reference for active control.

[0016] 2. This application uses multiple small-sized linear bearings instead of large-sized linear bearings, which greatly reduces the space occupied by the damper, and this installation method is applicable to dampers of different specifications and sizes.

[0017] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures pointed out in the description and the accompanying drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the overall internal structure in an embodiment of the present invention is shown.

[0020] Figure 2 A schematic diagram of cylindrical surface mounting in the prior art is shown.

[0021] Figure 3a A cross-sectional view of the static sliding assembly in an embodiment of the present invention is shown.

[0022] Figure 3b A schematic diagram of the static sliding assembly in an embodiment of the present invention is shown.

[0023] Figure 4a A schematic diagram of the small-scale fit between the slide and the linear bearing in an embodiment of the present invention is shown.

[0024] Figure 4b A schematic diagram of the large-size fit between the slide and the linear bearing in an embodiment of the present invention is shown.

[0025] Figure 5 A schematic diagram of the structure for adjusting the position of the component is shown in an embodiment of the present invention.

[0026] Figure 6 A schematic diagram of the overall external structure in an embodiment of the present invention is shown.

[0027] Figure 7a A diagram showing the vibration reduction effect of the dry friction damper in an embodiment of the present invention is provided.

[0028] Figure 7b A diagram showing the vibration reduction effect of the dry friction damper in an embodiment of the present invention is provided.

[0029] Figure 7c A diagram showing the vibration reduction effect of the dry friction damper in an embodiment of the present invention is provided.

[0030] In the diagram, 1. Load-bearing frame; 2. Locking nut one; 3. Waveform spring; 3. Adjusting bolt; 4. Mounting cylinder; 5. Damper support wall; 6. Stationary plate one; 7. Stationary plate two; 8. Dynamic friction plate; 9. Actuator; 10. Elastic support; 11. Bearing one; 12. Rotor main shaft; 13. Fixed plate; 14. Slide cylinder; 15. Linear bearing; 16. Elastic element; 17. Push rod; 18. Locking nut two; 19. Stationary friction plate. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] This invention aims to solve the problem of effectively controlling the bending mode vibration of the slender rotor of existing aero-engine power turbine rotors when operating under varying conditions across a wide airspace and speed range. Specifically, it addresses the following technical bottlenecks in the structural design and control implementation of existing spring-loaded dry friction dampers: the contradiction between the installation stiffness of the static friction plates: to achieve effective vibration reduction, the static friction plates must possess high radial stiffness to accurately transmit vibration, while simultaneously possessing low axial stiffness to flexibly adjust the normal force. Existing technologies (such as large-size cylindrical surface clearance fits or single large linear bearing installations) are difficult to achieve both, often resulting in insufficient radial stiffness or axial movement stagnation, affecting the damper's performance.

[0033] Initial state adjustment difficulties and uncontrollable passive damping: In the non-working state, the ideal "zero contact" initial state between the moving and stationary friction plates is difficult to guarantee through assembly. Unintentional pre-contact often occurs due to manufacturing errors, resulting in uncontrollable passive dry friction damping that interferes with the active control logic; or excessive initial clearance may occur, causing insufficient actuator stroke to establish effective positive pressure, leading to control failure. Relying on manually adjusting bolts and machining precision to set the initial state makes it difficult to accurately achieve and maintain the critical contact state of "zero preload" over a long period. This easily leads to uncontrollable damping in the non-working state or insufficient effective actuator stroke in the working state, affecting the reproducibility and reliability of the control effect.

[0034] Instability of friction pair state and thrust transmission loss: Traditional integral static friction plates are prone to local deformation when subjected to point loads of piezoelectric ceramic actuators, resulting in uneven force on the friction surface and deterioration of the contact state, causing thrust transmission loss of the actuator and reducing vibration reduction efficiency. At the same time, if the debris generated by friction and wear cannot be discharged in time, it will accumulate at the friction interface, which may lead to rolling friction or three-body wear. Debris accumulation may change the friction properties.

[0035] Bulky structure and poor space adaptability: The damper structure enlarged to meet the requirements of large rotor size often results in large size, increased weight, and difficult processing and assembly, making it difficult to meet the stringent requirements of aero engines for compact structure and lightweight, and making integrated design difficult.

[0036] This application provides a master-controlled spring-loaded dry friction damper, referenced... Figure 1 It includes a static sliding assembly, a static friction plate 19, a dynamic friction plate 8, an elastic support 10, an adjustment assembly, a load-bearing frame 1, and a damper support wall 5; The elastic support 10 is mounted on the rotor main shaft 12 via a bearing 11; the dynamic friction plate 8 is mounted on the first end face of the elastic support 10. The second end face of the elastic support 10 and the second end face of the damper support wall 5 are both connected to the load-bearing frame 1; The static sliding assembly and the adjusting assembly are both disposed between the elastic support 10 and the damper support wall 5; the static friction plate 19 is mounted on the static sliding assembly; the static sliding assembly controls the static friction plate 19 to be in parallel contact with the dynamic friction plate 8; the driving end of the adjusting assembly is provided with an actuator 9.

[0037] The actuator 9 is a piezoelectric ceramic actuator.

[0038] The core of actuator 9 is to provide controllable micro-displacement and positive pressure. Piezoelectric ceramic actuator 9 is preferred, but it can also be replaced by voice coil motor, magnetostrictive actuator 9, precision electric linear actuator, etc.; the installation method needs to be adjusted accordingly, but the principle of uniform circumferential loading should still be maintained.

[0039] The piezoelectric ceramic actuator of the damper has a cylindrical structure, and its main components include: a moving end (hemispherical head rod 17), a stainless steel shell, a piezoelectric ceramic plate, and an anti-torsional structure. The piezoelectric ceramic actuator exhibits electrostrictive effect, providing positive pressure to the friction pair. The magnitude of this positive pressure is related to the control voltage of the piezoelectric ceramic actuator; by controlling the voltage, the magnitude of the positive pressure in the friction pair can be changed. Three piezoelectric ceramic actuators are evenly distributed circumferentially, allowing the stationary friction plate 19 to move parallel to the circumference while ensuring that the positive pressure is evenly applied between the moving and stationary friction plates 19. Alternative solution: If redundancy is required, six piezoelectric ceramic actuators can be designed.

[0040] This application achieves extremely high radial installation stiffness and extremely low axial motion resistance through the design of connecting the static sliding assembly and the static friction plate 19, fundamentally solving the contradiction of installation stiffness; through the adjustable components, it ensures that the dynamic and static friction plates 19 are in a preset critical contact state after assembly, eliminating uncontrollable passive damping and providing a repeatable reference for active control.

[0041] This application resolves the installation stiffness conflict, optimizes friction pair contact, and achieves precise and controllable application of normal pressure by adjusting the component settings, resulting in a more effective damper for suppressing rotor vibration. (Reference) Figure 7a (Time: 0s~2s) Figure 7b (Time 1.6s~2s) and Figure 7c Experiments show that the integrated, main-controlled spring-loaded dry friction damper was tested on a high-pressure rotor simulator for an engine. Experimental results demonstrate that the damper effectively controls rotor vibration, achieving a maximum vibration reduction ratio of 95.5%. It exhibits good control performance at different critical speeds. This application represents a further structural optimization and innovation of a proven and effective technical solution. Its proposed improvements (modular sliding blocks, composite friction plates, etc.) aim to solve practical engineering problems in existing solutions, demonstrating high feasibility and practicality based on theory, simulation, and experimentation.

[0042] This application integrates the damper with the rotor elastic support 10 based on the piezoelectric ceramic actuator, realizing the integrated configuration design of the damper and the engine rotor support. It solves the problem that the existing piezoelectric folding active elastic dry friction damper requires the static friction plate 19 to have large radial stiffness and small axial stiffness, making it impossible to design accurately. It also solves practical engineering problems such as the inability to discharge friction debris and the entry of lubricating oil between the dynamic and static friction plates 19.

[0043] The static friction assembly includes a fixed plate 13, a sliding cylinder 14, a linear bearing 15, an elastic element 16, and a push rod 17. The first ends of the multiple sliding cylinders 14 are connected to the static friction plate 19 (connected by locking nuts 18), and the second ends of the sliding cylinders 14 are connected to the fixed plate 13. The linear bearing 15 is sleeved on the outer wall of the sliding cylinder 14. A groove is opened in the first end of the sliding cylinder 14, and the elastic element 16 is installed in the groove. The first end of the elastic element 16 is connected to the push rod 17, and the second end of the elastic element 16 is connected to the groove. The push rod 17 is in contact with the dynamic friction plate 8.

[0044] The static friction plate 19 needs to be radially fixed while allowing free axial movement. (According to existing technical literature) the damper achieves optimal vibration reduction when the installation stiffness (radial direction) of the static friction plate 19 is more than one order of magnitude greater than the support stiffness; that is, the greater the radial installation stiffness, the better. Simultaneously, the static friction plate 19 is required to move flexibly along the axial direction to adjust the magnitude of the normal force; that is, the smaller the axial stiffness, the better. This contradiction between the large radial installation stiffness and the small axial stiffness increases the design difficulty of the static friction plate 19.

[0045] refer to Figure 2 In existing spring-loaded dry friction dampers, the static friction plate 19 is integrally mounted in the stationary component using a cylindrical surface fit. When mounting the static friction plate 19 using this method, a clearance fit is necessary to allow axial movement. However, when the static friction plate 19 is large (e.g., in large rotors), this method becomes difficult. This is because, for the same precision requirements, larger parts are more difficult to manufacture, more expensive, and more difficult to assemble. After assembly, due to the clearance, the cylindrical axis of the static friction plate 19 is not parallel to the cylindrical axis of the stationary component. Figure 2 As shown in the enlarged image (this non-parallelism is magnified), coupled with manufacturing errors, this non-parallelism can cause the inner and outer rings of the sliding block to become stuck. The more the inner and outer rings of the sliding block tilt, the more likely this sticking will occur, ultimately preventing the damper from converting the thrust of the actuator 9 into the normal force of the dynamic and static friction plates 19 as effectively as possible. Therefore, it is necessary to consider solutions to the sliding difficulties caused by sliding friction and tilting issues.

[0046] Under the same clearance dimension processing requirements, the static friction plate 19 assembly has a large size due to the radial dimension of its inner ring being constrained by the size of the shaft. Its inner diameter must be larger than the outer diameter of the shaft, resulting in a large volume and increased component weight. Furthermore, the linear bearing 15 is a standard part, limiting bearing selection as the damper size increases. Increased bearing size occupies more space and adds weight. Considering the actual structural characteristics, a large cylindrical surface fit is not suitable for installing large static friction plates 19 because it occupies a significant amount of space and involves substantial processing difficulty and cost.

[0047] To solve the above problems, this application changes the fixing method of the static friction plate 19 from a single large-sized sliding assembly to a combination of three small-sized static sliding assemblies, such as... Figure 3a and Figure 3b As shown, the static friction plate 19 is locked to the slide cylinder 14 by the locking nut 18. The slide cylinder 14 is fitted with the linear bearing 15 to ensure a 0-1 clearance fit. The linear bearing 15 is assembled into the mounting cylinder 4 and fixed to the damper support wall 5 as a stationary component. A fixing plate 13 is installed at the left end of the slide cylinder 14. Its function is to enhance the perpendicularity between the static friction plate 19 and the linear bearing 15 by ensuring the parallelism of the mating surfaces, thus ensuring the parallelism between the static friction plate 19 and the dynamic friction plate 8 during installation.

[0048] Specifically, the combination of three linear bearings 15 and slide cylinders 14 achieves minimal axial installation stiffness and large radial installation stiffness for the static friction plate 19. The function of the fixing plate 13 is to enhance the parallelism of the installation of the three slide cylinders 14, thereby improving the perpendicularity of the static friction plate 19 to the rotor axis and ensuring parallel contact between the dynamic friction plate 8 and the static friction plate 19. The push rod 17 is hemispherical, and the combination of the elastic element 16 and the push rod 17 is such that one end of the elastic element 16 acts on the dynamic friction plate 8, and the other end reacts on the slide cylinder 14, providing the slide cylinder 14 and the static friction plate 19 with a force opposite to that of the actuator 9. This allows the static friction plate 19 to return to its initial adjustment state when the output displacement of the actuator 9 returns to zero, ensuring the repeatability of the applied positive pressure. At the same time, the push rod 17 and the slide cylinder 14 are clearance-fitted, ensuring that the push rod 17 has a certain amount of radial movement space and does not affect the radial vibration of the dynamic friction plate 8.

[0049] The use of multiple small linear bearings 15 evenly distributed circumferentially replaces the use of a single large bearing or a large-diameter cylindrical surface. The advantages are: significantly improved radial overall stiffness: multi-point constraints form stable support. Significantly reduced axial friction: rolling friction is much lower than sliding friction, resulting in more flexible movement. Enhanced spatial adaptability: small bearings are easier to select, process, and assemble, significantly reducing the overall radial size and weight, facilitating integrated design; the fixed plate 13 ensures the parallelism of the multiple linear bearings 15, thereby guaranteeing the parallel contact of the dynamic and static friction plates 19.

[0050] The core function of linear bearing 15 is to provide low-friction axial guidance. In addition to linear ball bearings, linear roller bearings, self-lubricating composite bushings (such as PTFE composite bushings) or hydrostatic air / liquid floatation guides can also be considered (in extremely high precision or special environments). Any guide mechanism that meets the principle of "high radial constraint and low axial friction" can be regarded as an alternative implementation of the static sliding group concept.

[0051] refer to Figure 4a and Figure 4b This figure shows the effect of the axial dimension of the linear bearing on the degree of non-parallelism, and the non-parallelism of linear bearings 15 of different lengths under the same radial machining tolerance. The figure exaggerates the clearance between the slide cylinder 14 and the linear bearing 15. It can be clearly seen from the figure that θ1>θ2. From the geometric relationship, the maximum tilt angle between the slide cylinder 14 and the linear bearing 15 is approximately: (1) Where Δr is the single-sided clearance between the slide cylinder 14 and the linear bearing 15, l is the axial length of the linear bearing 15, and θ is the tilt angle. As can be seen from the formula, the larger l is, the smaller its maximum tilt angle; the smaller Δr is, the smaller its maximum tilt angle. Δr depends on the machining accuracy, while l depends on the selection of the linear bearing 15. Therefore, to reduce the maximum tilt angle and ensure the parallelism of the dynamic and static friction plates 19, when selecting the linear bearing 15, both dimensions and machining accuracy should be considered comprehensively, and a linear bearing 15 model with the longer dimensions should be selected whenever possible.

[0052] The combination of the static friction plate 19 and the static sliding assembly in this application resolves the contradiction in damper design where the static friction plate 19 has low axial installation stiffness and high radial installation stiffness. By replacing the large linear bearing 15 with multiple small linear bearings 15, the space occupied by the damper is greatly reduced, and this installation method is applicable to dampers of different specifications and sizes.

[0053] This application solves the contradiction between the large radial stiffness and weak axial stiffness of the static friction plate 19 required for vibration reduction in dry friction dampers. At the same time, the extremely small axial stiffness solves the problem of piezoelectric ceramic output thrust loss caused by the initial gap during machining when adjusting the initial contact state of the dynamic and static friction plates 19.

[0054] The static friction plate 19 includes a first static plate 6 and a second static plate 7; the first static plate 6 is connected to the second static plate 7, and the first static plate 6 is in contact with the moving friction plate 8; the second static plate 7 is connected to the output point of the actuator 9.

[0055] In this application, the static friction plate 19 adopts a double-ring composite structure design, and its outer diameter is consistent with that of the mating dynamic friction plate 8. Static plate 6 (static friction plate 19-1), as a key component that directly contacts the dynamic friction plate 8 and bears the friction function, is made of copper. This material not only provides a stable and suitable coefficient of friction but also promotes surface adhesion between the dynamic and static friction plates 19, thereby improving the contact state of the friction pair interface. Static plate 7 (static friction plate 19-2) is made of 40Cr alloy steel, and its main function is to effectively distribute the concentrated point load output by the piezoelectric ceramic actuator to the entire friction plane, achieving uniform pressure distribution. Furthermore, the 40Cr material possesses high hardness and resistance to deformation, which can significantly suppress potential local deformation under the high thrust of the piezoelectric ceramic actuator, avoiding thrust transmission loss caused by structural materials, thereby ensuring effective transmission of actuator output force and actuation accuracy. A composite structure of "soft friction layer (copper) + hard backplate (alloy steel)" is adopted; the hard backplate effectively resists the point load impact of the piezoelectric ceramic, avoiding local deformation and ensuring pressure is evenly transmitted to the entire friction surface; the soft friction layer provides a stable and high coefficient of friction and improves surface adhesion. This solves the problems of easy deformation and large thrust transmission loss in the integral static friction plate 19.

[0056] The friction layer material in stationary plate 6 can be other copper alloys, powder metallurgy materials or specific engineering plastics, provided that the friction performance is guaranteed; the back plate of stationary plate 7 can be other high-strength alloy steel, titanium alloy or ceramic matrix composite material.

[0057] In one embodiment of the present invention, reference is made to Figure 5 The adjustment assembly includes a locking nut 2, an adjusting bolt 3, and a wave spring 203; the first end of the adjusting bolt 3 contacts the actuator 9, the second end of the adjusting bolt 3 passes through the fixing plate 13, and the wave spring 203 is sleeved on the adjusting bolt 3; the locking nut 2 is threadedly engaged with the adjusting bolt 3.

[0058] After the damper is assembled, the actuator 9 can be moved within the mounting cylinder 4 by precisely tightening the adjusting bolt 3. This allows for compensation and adjustment of the initial dimensional clearance within the system, thereby precisely eliminating the initial clearance between the moving and stationary friction plates 19 caused by manufacturing tolerances, the actuator 9's own installation dimensional errors, and accumulated assembly errors. This ensures that the friction pair is in a preparatory state of critical contact when the actuator 9 is not energized, thus providing the necessary structural prerequisite for the precise and efficient active control of the subsequent piezoelectric ceramic actuator; and resolving the design contradiction between "initial state separation" and "contact during operation".

[0059] Meanwhile, the presence of locking nut 2 and wave spring 203 provides sufficient bearing preload for adjusting bolt 3, solving the problem of bolt loosening under the conditions of large-range output of the piezoelectric ceramic actuator and rotor vibration transmission. Furthermore, the use of thread-locking adhesive further ensures the stability of the piezoelectric ceramic actuator under repeated output and long-term preload maintenance; achieving: sub-micron level precise initial state setting, ensuring consistency of the reference state. Reliable vibration anti-loosening, through double-nut locking and elastic element anti-loosening, ensures that the initial state does not drift under the harsh vibration environment of the engine; this fundamentally solves the problem of uncontrollable initial state.

[0060] The adjusting bolt 3 plays a key role in the assembly and initial state setting of the damper. Its core function is to drive the static friction plate 19 to produce a micro displacement along the axial direction by precisely adjusting the adjusting bolt 3 when the dynamic and static friction plates 19 are in the initial gap state, until they achieve the preset initial contact state with the dynamic friction plate 8, thereby ensuring that the damper is under a consistent and controllable initial positive pressure condition when the input of the piezoelectric ceramic actuator is zero.

[0061] To achieve this function, the adjusting bolt 3 must possess reliable self-locking capability to prevent initial state drift due to loosening under high-frequency vibration conditions of the rotor system. Referring to the double-nut locking anti-loosening principle widely used in mechanical connections, this application adds a locking nut 2 to the adjusting bolt 3. After adjustment to the target position, tightening the locking nut 2 generates axial clamping force between the threads of the adjusting bolt 3 and the locking nut 2, forming a frictional self-locking between the threaded pairs, thereby effectively suppressing rotational loosening caused by vibration. This structure effectively improves the ability of the adjusting bolt 3 to maintain its state under dynamic operating conditions, reduces the uncertainty of the damper's initial state caused by loosening, and ensures the long-term stability of vibration reduction performance.

[0062] The core of the adjustment component is precision fine-tuning and anti-loosening; the adjustment bolt 3 can be replaced with a fine-tuning mechanism such as an eccentric wheel, wedge block, or micrometer head; in addition to mechanical locking nuts, existing anti-loosening technologies such as threaded adhesive, cotter pins, and wire thread inserts can also be used to prevent loosening.

[0063] This application utilizes an adjustment mechanism for locking and fine-tuning, ensuring consistent baseline conditions for each operation and eliminating interference from uncontrollable passive damping. The composite static friction plate 19 and stable static sliding guide make the thrust transmission of the piezoelectric ceramic more efficient and linear, improving the accuracy and response speed of active control.

[0064] refer to Figure 6 Where a is the actuator 9 cable, and an installation cylinder 4 is provided between the elastic support 10 and the damper support wall 5. The first end of the installation cylinder 4 is fixedly connected to the damper support wall 5. The actuator 9 and the static sliding assembly are integrated in the installation cylinder 4.

[0065] In this application, the actuator 9, static sliding group, adjustment assembly and other components are all compactly integrated in the mounting cylinder 4. The mounting cylinder 4 can be directly used as part of the engine load-bearing frame 1 or connected to it, realizing the structural and modular integration of the damper and the engine rotor support system, which greatly improves the feasibility of engineering applications.

[0066] The linear bearing 15 has a small interference fit with the mounting sleeve 4.

[0067] The mounting cylinder 4 is interference-fitted with the damper support wall 5 and is axially tightened and fixed by bolts. The dynamic friction plate 8 is fixed to the end face of the elastic support 10 and forms an integral part with the elastic support 10. The two static friction plates 19 are connected as a whole by countersunk screws. The linear bearing 15 is slightly interference-fitted with the mounting cylinder 4 and becomes an integral part with the mounting cylinder 4 by cold assembly. The modular and miniaturized design greatly reduces the size and weight of the damper itself, making it easier to arrange and integrate under the harsh space and weight constraints of aero engines. The modular design allows the damper to be assembled, debugged and replaced as a whole unit, simplifying the assembly process on the engine and facilitating later maintenance.

[0068] Chip removal holes are provided on the friction surface of the dynamic friction plate 8.

[0069] The dynamic friction plate 8 adopts a split connection: the dynamic friction plate 8 is fixed to the end face of the elastic support 10 by bolts, and an interference fit is used between the dynamic friction plate 8 and the elastic support 10 structure. This fit can effectively limit the radial vibration displacement of the dynamic friction plate 8, ensuring that it and the bearing housing of the elastic support 10 maintain the consistency of radial vibration under dynamic conditions, thereby improving the stability and vibration reduction capability of the damper system; at the same time, the split design of the dynamic friction plate 8 can realize the independent replacement of the dynamic friction plate 8, which greatly reduces the manufacturing cost.

[0070] Furthermore, to ensure the friction performance of the friction interface between the dynamic and static friction pairs during long-term operation, the dynamic friction plate 8 is provided with several regularly arranged circular holes, micro-through holes, or non-through grooves between its inner and outer diameters. These channels can promptly discharge the tiny debris generated by wear during friction, and can use centrifugal force or airflow to promptly discharge the wear debris generated by friction from the friction interface during vibration, maintaining interface cleanliness and long-term stability of friction performance, and preventing wear debris from accumulating between the friction interfaces and affecting the contact state, thereby maintaining the stability and controllability of the sliding friction behavior between the dynamic and static friction plates 19. The chip removal hole design reduces the harm of wear debris, the composite friction plate reduces plastic deformation, and the linear bearing 15 has low guide wear. All of these contribute to maintaining the stability of the damper's performance and extending its service life during long-term operation.

[0071] The elastic element 16 is a return spring, a butterfly spring, or a rubber elastomer.

[0072] Alternatively, the restoring force of the actuator 9 itself can be utilized (such as in certain dual piezoelectric crystal structures).

[0073] In the design of spring-loaded dry friction dampers, the structural scheme has a decisive influence on their vibration reduction performance and operational reliability. To improve the overall performance of the damper, this application optimizes the installation method, significantly reducing the axial stiffness while maintaining the necessary radial stiffness and optimizing the size and space of the damper, thereby enhancing its engineering applicability. Secondly, based on the output characteristics of the piezoelectric ceramic actuator 9 and the operating requirements of the friction pair, the material properties and structural dimensions of the static friction plate 19 are comprehensively optimized and the structure is designed. Addressing the issue of poor stability in the reference state (i.e., the uncontrolled state) during damper commissioning and operation, the components of the adjustment assembly are improved and the operating procedure is standardized, effectively improving the repeatability and controllability of the system. Simultaneously, this application solves the problem of excessive axial stiffness affecting vibration response sensitivity during the installation of the static friction plate 19 in existing mounting ring structures, as well as the problems of excessive volume and difficulty in bearing selection associated with traditional linear bearing 15 installation methods.

[0074] In one embodiment of the present invention, a method for using a master-controlled spring-loaded dry friction damper, based on the above-described master-controlled spring-loaded dry friction damper, includes: The dry friction damper is assembled in sequence (specifically, the actuator 9 and the static sliding assembly are first installed on the mounting cylinder 4, and then the mounting cylinder 4 is installed between the damper support wall 5 and the elastic support 10. The mounting cylinder is fixed to the damper support wall 5 with bolts). The adjustment components are then adjusted so that the static sliding group moves axially until the static friction plate 19 and the dynamic friction plate 8 make microscopic contact. When the actuator 9 is not powered on, the force of the static sliding block keeps the dynamic friction plate 8 and the static friction plate 19 slightly separated. When rotor vibration needs to be controlled, the control system applies a control voltage to actuator 9 based on the vibration signal. Actuator 9 pushes the static friction plate 19 to press the dynamic friction plate 8; After the control requirement ends, the voltage of actuator 9 is withdrawn, and the static slider returns to its initial state under the action of the static slider group.

[0075] 1. Initial State Setting: After assembly, rotate the adjusting bolt 3 to push the static friction plate 19 sliding assembly axially until the static friction plate 19 and the moving friction plate 8 reach microscopic contact (the perceptible contact force is close to zero). Then, tighten the locking nut 2 and the auxiliary wave spring 203 to provide anti-loosening locking force, fixing this state. At this time, the piezoelectric ceramic actuator is not energized, and the force of the return spring keeps the friction pair slightly separated.

[0076] 2. Active vibration reduction process: When rotor vibration needs to be controlled, the control system applies a control voltage to the piezoelectric ceramic actuator based on the vibration signal (such as speed and amplitude). The actuator undergoes axial elongation, overcoming the spring's restoring force and pushing the stationary friction plate 19 to press against the moving friction plate 8. The normal force N is proportional to the voltage. The rotor vibration causes the moving friction plate 8 to perform a slight radial translation, resulting in relative sliding between it and the stationary friction plate 19. The dry friction force dissipates the vibration energy.

[0077] 3. Variable stiffness adjustment: Through control algorithms, the magnitude of the normal force can be adjusted, and even the "contact-separation" state switching of the friction pair can be achieved. When it is necessary to change the critical speed of the rotor system, the friction pair can be controlled to be in a "slippery" critical contact state. At this time, the friction interface provides additional stiffness, thereby changing the total equivalent stiffness of the support and realizing the active adjustment of the rotor mode.

[0078] 4. State Reset: When the control demand ends and the actuator voltage is removed, the actuator retracts. Under the action of the reset spring, the sliding block of the stationary friction plate 19 is pushed back, and the moving and stationary friction plates 19 return to the separated or critical contact state, waiting for the next command.

[0079] The core performance indicators of this application are the target parameter ranges pursued by the damper, such as: the design normal pressure adjustment range (e.g., 0-5000N), the target value of radial mounting stiffness of the 19 static friction plate components (e.g., >1e8 N / m), the target value of axial motion static friction force (e.g., <5N), the applicable rotor mass range, and the operating temperature range. In addition to aero-engine power turbine rotors, the damper of this application is also suitable for other high-speed rotating machinery, such as gas turbines, centrifugal compressors, high-speed motors, and flywheel energy storage systems, which require wide-frequency domain vibration active control.

[0080] Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A master-controlled spring-loaded dry friction damper, characterized in that, It includes a static sliding assembly, a static friction plate (19), a dynamic friction plate (8), an elastic support (10), an adjustment assembly, a load-bearing frame (1), and a damper support wall (5). The elastic support (10) is mounted on the rotor main shaft (12) via a bearing (11); the dynamic friction plate (8) is mounted on the first end face of the elastic support (10); The second end face of the elastic support (10) and the second end face of the damper support wall (5) are both connected to the load-bearing frame (1); The static sliding assembly and the adjusting assembly are both located between the elastic support (10) and the damper support wall (5); the static friction plate (19) is mounted on the static sliding assembly; the static sliding assembly controls the static friction plate (19) to be in parallel contact with the dynamic friction plate (8); the driving end of the adjusting assembly is provided with an actuator (9), which pushes the static friction plate (19) to press the dynamic friction plate (8). The static friction assembly includes a fixed plate (13), a sliding cylinder (14), a linear bearing (15), an elastic element (16), and a push rod (17); the first ends of the multiple sliding cylinders (14) are connected to the static friction plate (19), and the second ends of the sliding cylinders (14) are connected to the fixed plate (13); the linear bearing (15) is sleeved on the outer wall of the sliding cylinder (14); a groove is opened in the first end of the sliding cylinder (14), and the elastic element (16) is installed in the groove; the first end of the elastic element (16) is connected to the push rod (17), and the second end of the elastic element (16) is connected to the groove; the push rod (17) is in contact with the dynamic friction plate (8); The adjustment assembly includes a locking nut (2), an adjusting bolt (3), and a wave spring (203); the first end of the adjusting bolt (3) contacts the actuator (9), the second end of the adjusting bolt (3) passes through the fixing plate (13), and the wave spring (203) is sleeved on the adjusting bolt (3); the locking nut (2) is threadedly engaged with the adjusting bolt (3).

2. The master-controlled spring-loaded dry friction damper according to claim 1, characterized in that, The static friction plate (19) includes a first static plate (6) and a second static plate (7); the first static plate (6) is connected to the second static plate (7), and the first static plate (6) is in contact with the moving friction plate (8); the second static plate (7) is connected to the output point of the actuator (9).

3. The master-controlled spring-loaded dry friction damper according to claim 1, characterized in that, An installation cylinder (4) is provided between the elastic support (10) and the damper support wall (5), and the first end of the installation cylinder (4) is fixedly connected to the damper support wall (5); the actuator (9) and the static sliding assembly are integrated inside the installation cylinder (4).

4. A master-controlled spring-loaded dry friction damper according to claim 3, characterized in that, The linear bearing (15) has a small interference fit with the mounting sleeve (4).

5. A master-controlled spring-loaded dry friction damper according to claim 4, characterized in that, The friction surface of the dynamic friction plate (8) is provided with chip removal holes.

6. A master-controlled spring-loaded dry friction damper according to claim 4, characterized in that, The elastic element (16) is a return spring.

7. A master-controlled spring-loaded dry friction damper according to claim 6, characterized in that, The actuator (9) is a piezoelectric ceramic actuator.

8. A method of using a master-controlled spring-loaded dry friction damper, based on the master-controlled spring-loaded dry friction damper according to any one of claims 1-7, characterized in that, include: The dry friction dampers are assembled sequentially. The adjustment components are then adjusted so that the static sliding group moves axially to the point where the static friction plate (19) and the dynamic friction plate (8) are in microscopic contact. When the actuator (9) is not powered on, the force of the static sliding block keeps the dynamic friction plate (8) and the static friction plate (19) slightly separated. When rotor vibration needs to be controlled, the control system applies control voltage to the actuator (9) according to the vibration signal; The actuator (9) pushes the static friction plate (19) to press the dynamic friction plate (8); After the control demand ends, the voltage of the actuator (9) is withdrawn, and the static sliding plate returns to its initial state under the action of the static sliding block.

Images