Nonlinear spring three-dimensional vibration isolation support for wooden wind power tower

Abstract

The application provides a nonlinear spring three-dimensional vibration isolation support for a wooden wind power tower, and belongs to the technical field of wind power generation.The support comprises connecting plates and a spring system arranged between the connecting plates, the spring system comprises a central spring assembly, a forward inclined spring assembly and a reverse inclined spring assembly, the central spring assembly is located at the central position of the connecting plates, the top end of the forward inclined spring assembly is adjacent to the top end of the central spring assembly, and the bottom end of the forward inclined spring assembly is away from the bottom end of the central spring assembly, so that a forward inclined state is formed; the top end of the reverse inclined spring assembly is away from the top end of the central spring assembly, and the bottom end of the reverse inclined spring assembly is adjacent to the bottom end of the central spring assembly, so that a reverse inclined state is formed.The inclined spring assembly is introduced in the application, the horizontal component stiffness is significantly reduced while the vertical stiffness is ensured, and the flexible vibration isolation effect in the horizontal direction is effectively realized.

Description

Technical Field

[0001] This invention belongs to the field of wind power generation technology, specifically relating to a nonlinear spring three-dimensional vibration isolation support for wooden wind power generation towers. Background Technology

[0002] Wind power generation, as a clean and renewable energy technology, has been widely used globally. Currently, wind turbine towers extensively use steel structures. However, steel towers suffer from significant weight, placing high demands on foundation load-bearing capacity and lifting equipment performance. To address this, some technologies in this field have explored incorporating wood into wind turbine tower structures, creating wooden towers. Wood, as a natural biomass material, possesses advantages such as high specific strength, light weight, renewability, and low processing energy consumption, significantly reducing the overall weight of the tower. In wooden tower structures, the weakest and most sensitive area is the connection zone at the top where the wind turbine is installed. This connection zone is subjected to long-term vibrations and alternating loads from the wind turbine's nacelle, easily leading to connection deformation and long-term performance degradation. To address this issue, a common practice is to install vibration isolation supports at this location, reducing the dynamic load transmitted from the nacelle to the top of the wooden tower structure.

[0003] In existing technologies, vibration isolation bearings are typically spring bearings, which consist of several vertically extending steel springs placed between two mounting plates. The elasticity of the steel springs is used to isolate vibrations. However, the vertical spring system has the following drawbacks: (1) The large horizontal stiffness of the vibration is insufficient to generate enough horizontal displacement of the support. The horizontal vibration generated by the wind turbine power system nacelle is transmitted to the wooden tower with almost no attenuation, causing the vibration isolation to fail. (2) The structure lacks stiffness adjustability. Once the vibration isolation support is manufactured, its stiffness is fixed and cannot be finely adjusted on the construction site according to the actual weight of the upper wind turbine. If the stiffness of the support does not match the actual mass, it will be difficult to achieve the expected best vibration isolation effect.

[0004] Therefore, it is necessary to provide a nonlinear spring three-dimensional vibration isolation support for wooden wind turbine towers to solve the above problems. Summary of the Invention

[0005] This invention provides a nonlinear spring three-dimensional vibration isolation support for wooden wind power generation towers, aiming to solve the problems of low horizontal vibration isolation efficiency and unadjustable stiffness of existing vibration isolation supports.

[0006] To solve the above-mentioned technical problems, the present invention is implemented as follows: A nonlinear spring three-dimensional vibration isolation support for wooden wind turbine towers, comprising: Two spaced-apart connecting plates, one connected to the wind turbine and the other to the wooden tower structure; A spring system connecting the two connecting plates, the spring system comprising: The central spring assembly is located at the center of the connecting plate. A positively tilted spring assembly has its top end close to the top end of the central spring assembly and its bottom end far from the bottom end of the central spring assembly, forming a positively tilted state. The reverse tilting spring assembly has its top end away from the top end of the central spring assembly and its bottom end close to the bottom end of the central spring assembly, forming a reverse tilting state. There are multiple positive tilting spring assemblies and multiple negative tilting spring assemblies, which are evenly distributed around the central spring assembly.

[0007] As a preferred improvement, the two connecting plates are divided into an upper connecting plate and a lower connecting plate. The upper connecting plate is used to connect with the wind turbine, and the lower connecting plate is used to connect with the wooden tower. The upper connecting plate and the lower connecting plate are parallel and spaced apart.

[0008] As a preferred improvement, the central axes of the upper connecting plate, the lower connecting plate, and the central spring assembly are located on the same straight line.

[0009] As a preferred improvement, there are three of each of the forward tilting spring assembly and the reverse tilting spring assembly, and the forward tilting spring assembly and the reverse tilting spring assembly are arranged alternately.

[0010] As a preferred improvement, the central spring assembly includes a central spring and two central spring seats disposed at both ends of the central spring for mounting the central spring; the central spring seat includes a central spring guide post and a central spring base disposed around the central spring guide post and spaced apart therefrom to form a mounting groove, and the end of the central spring is sleeved on the central spring guide post and limited within the mounting groove.

[0011] As a preferred improvement, the height of the central spring guide post is greater than the height of the central spring base.

[0012] As a preferred improvement, both the forward tilting spring assembly and the reverse tilting spring assembly include a tilting spring, a mounting base, and an adjusting base; the mounting base is used to fix the end of the tilting spring, the adjusting base is connected between the connecting plate and the mounting base, and the adjusting base has an angle adjustment function to change the tilt angle of the tilting spring.

[0013] As a preferred improvement, the adjusting base includes ear plates, a pin, a fixed plate, a movable plate, and a torsion spring; the two ear plates are arranged relatively apart, the two ends of the pin are fixed to the two ear plates respectively, the fixed plate is fixed to the connecting plate and located between the two ear plates, one end of the movable plate is hinged to the fixed plate, and the other end is suspended, the torsion spring is sleeved on the pin, and the two torsion arms of the torsion spring abut against the suspended ends of the fixed plate and the movable plate respectively; the mounting base is fixed to the movable plate.

[0014] As a preferred improvement, the mounting base includes a base and a guide post, the guide post and the central axis of the base are on the same straight line, and the radial dimension of the guide post is smaller than the radial dimension of the base, and the tilting spring is sleeved on the guide post and abuts against the base.

[0015] As a preferred improvement, the central spring and the tilting spring are covered with a rubber layer.

[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention provides vertical bearing capacity by setting a central spring assembly, and sets a positive tilting spring assembly and a negative tilting spring assembly in a triangular pyramidal spatial distribution. By utilizing the vector decomposition of the axial stiffness of the tilting spring, the horizontal component stiffness is significantly reduced while ensuring the vertical stiffness, thus effectively achieving a flexible vibration isolation effect in the horizontal direction. (2) By setting an adjustment base with angle adjustment function, the tilt angle of the tilt spring can be adaptively adjusted according to the actual weight of the upper wind turbine and the vibration isolation requirements, so as to realize the real-time correction of the horizontal stiffness and vertical stiffness of the support. (3) The present invention forms an effective buffer mechanism in both the horizontal and vertical directions by symmetrically and alternately arranging the forward tilting spring assembly and the reverse tilting spring assembly. In particular, in the vertical direction, the axial compression / tension component of the tilting spring works in conjunction with the central spring to make the vertical stiffness a controllable elastic parameter, which can effectively absorb vertical impact energy and avoid secondary impact damage after the structure is lifted, thus achieving true three-dimensional vibration isolation. (4) The present invention uses three positive tilting springs to form a positive triangular pyramid spatial support system and three negative tilting springs to form a negative triangular pyramid spatial support system. The symmetrically arranged triangular pyramid structure has a large torsional moment of inertia. Compared with a single support or a single-direction tilting spring arrangement, it can significantly enhance the torsional stiffness and effectively suppress the torsional effect. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of 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, wherein: Figure 1 A reference diagram showing the usage status of the nonlinear spring three-dimensional vibration isolation support for wooden wind turbine towers provided by the present invention. Figure 2 A three-dimensional structural diagram of a nonlinear spring three-dimensional vibration isolation support for wooden wind turbine towers provided by the present invention; Figure 3 express Figure 2 The view shown is of a nonlinear spring three-dimensional vibration isolation support for a wooden wind turbine tower. Figure 4 A diagram showing the spatial relationship between the spring system and the connecting plate; Figure 5 A diagram showing the planar positional relationship between the spring system and the connecting plate; Figure 6 A diagram showing the connection structure between the center spring and the center spring seat; Figure 7 A schematic diagram showing the exploded structure of the central spring and the central spring seat; Figure 8 A diagram showing the connection structure of the tilting spring, mounting base, and adjusting base; Figure 9 A diagram showing the connection structure of the mounting base and the adjusting base; Figure 10 express Figure 9 An exploded view of the connection structure shown. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] like Figures 1-10As shown, this embodiment provides a nonlinear spring three-dimensional vibration isolation support 100 for wooden wind turbine towers, disposed between the wooden tower 200 and the wind turbine 300. It supports the wind turbine 300, reduces the vibration generated by the nacelle of the wind turbine 300's power system, lowers the amplitude of the alternating load acting on the steel-wood transition interface, and protects this critical connection point from premature deformation, loosening, and performance degradation. The number of nonlinear spring three-dimensional vibration isolation supports 100 is selected according to actual needs.

[0020] In this embodiment, both the wooden tower 200 and the wind turbine 300 can adopt conventional structures in the art. Specifically, the wall of the wooden tower 200 has a layered structure, including a press-fit wood layer 201, a reinforcing layer 202, and a protective layer 203 arranged sequentially from the inside out. The press-fit wood layer 201 serves as the main structural component, bearing the main load. The reinforcing layer 202 (e.g., glass fiber or carbon fiber) is wrapped or laid on the surface of the press-fit wood layer 201 to improve circumferential stiffness and provide additional bending and fatigue resistance. The protective layer 203 (e.g., epoxy paint) mainly serves to waterproof and resist aging.

[0021] The nonlinear spring three-dimensional vibration isolation support 100 includes two parallel and spaced connecting plates 10 and a spring system 20 connected between the two connecting plates 10.

[0022] The connecting plate 10 serves as the connection component between the nonlinear spring three-dimensional vibration isolation support and the external environment. Specifically, it includes an upper connecting plate 11 and a lower connecting plate 12. The upper connecting plate 11 is used to connect with the wind turbine 300, and the lower connecting plate 12 is used to connect with the wooden tower 200. The upper connecting plate 11 and the lower connecting plate 12 are parallel and spaced apart, and their central axes are located on the same straight line to maintain the consistency of the center of gravity.

[0023] The spring system 20, as the core component for vibration isolation, includes a central spring assembly 21, a forward tilting spring assembly 22, and a reverse tilting spring assembly 23. The two ends of the central spring assembly 21, the forward tilting spring assembly 22, and the reverse tilting spring assembly 23 are respectively connected to the two connecting plates 10.

[0024] The central spring assembly 21 is connected to the center of the connecting plate 10, and its central axis is on the same straight line as the central axis of the connecting plate 10. The top end of the positive tilting spring assembly 22 is close to the top end of the central spring assembly 21, and its bottom end is far from the bottom end of the central spring assembly 21, forming a positive tilt state; the top end of the negative tilting spring assembly 23 is far from the top end of the central spring assembly 21, and its bottom end is close to the bottom end of the central spring assembly 21, forming a negative tilt state. Structurally, both the positive tilting spring assembly 22 and the negative tilting spring assembly 23 are tilted relative to the central spring assembly 21. It should be noted that "close to" means that the distance between the objects involved should be as small as possible to avoid interference, and "far from" means that the distance between the objects involved should be as large as possible. Taking the positive tilting spring assembly 22 as an example, its top end needs to be as close as possible to the top end of the central spring assembly 21, and its bottom end is located at the edge of the lower connecting plate 12 to ensure that it is far from the bottom end of the central spring assembly 21.

[0025] The number of positive tilting spring assemblies 22 and negative tilting spring assemblies 23 are all three, arranged in a circular array around the central spring assembly 21. That is, the angle between two adjacent positive tilting spring assemblies 22 on the horizontal projection plane is 120 degrees, and the angle between two adjacent negative tilting spring assemblies 23 on the horizontal projection plane is also 120 degrees. The positive tilting spring assemblies 22 and the negative tilting spring assemblies 23 are staggered, meaning that one negative tilting spring assembly 23 is placed between two adjacent positive tilting spring assemblies 22, and one positive tilting spring assembly 22 is placed between two adjacent negative tilting spring assemblies 23. Preferably, a total of six tilting spring assemblies (positive tilting spring assemblies 22 and negative tilting spring assemblies 23) are evenly distributed around the central spring assembly, meaning that the angle between two adjacent tilting spring assemblies on the horizontal projection plane is 60 degrees.

[0026] The three forward tilting spring assemblies 22 form a forward-stabilized triangular pyramidal spatial support system with the plane of the lower connecting plate 12 as its base, and the three reverse tilting spring assemblies 23 form a reverse-stabilized triangular pyramidal spatial support system with the plane of the upper connecting plate 11 as its base. This symmetrically arranged triangular pyramidal structure has a large torsional moment of inertia, which significantly enhances the torsional stiffness of the bottom of the wind turbine 300 compared to a single support or a unidirectional tilting spring arrangement, effectively suppressing its torsional effect under external loads. The central spring assembly 21 provides linear vertical bearing capacity, and together with the nonlinear stiffness exhibited by the forward tilting spring assembly 22 and the reverse tilting spring assembly 23, achieves quasi-zero stiffness characteristics, realizing a three-dimensional vibration isolation effect.

[0027] The central spring assembly 21 includes a central spring 211 and two central spring seats 212 disposed at both ends of the central spring 211 for fixing the central spring 211. The two central spring seats 212 have the same structure, one of which is fixed to the upper connecting plate 11 and the other is fixed to the lower connecting plate 12.

[0028] The central spring seat 212 includes a central spring guide post 2121 and a central spring base 2122 arranged around the central spring guide post 2121 and spaced apart to form an installation groove 2123. The central spring guide post 2121 and the central spring base 2122 are both fixed to the connecting plate 10, preferably integrally formed with the connecting plate 10.

[0029] The end of the central spring 211 is sleeved on the central spring guide post 2121 and limited in the mounting groove 2123. The mounting groove 2123 constitutes a radial limit for the central spring 211, and the two connecting plates 10 constitute an axial limit for the central spring 211. This method can ensure that the central spring 211 only undergoes axial deformation.

[0030] The height of the central spring guide post 2121 is greater than the height of the central spring base 2122, which can provide a greater degree of guidance for the central spring 211 and prevent the central spring 211 from coming out when under tension.

[0031] The forward tilting spring assembly 22 and the reverse tilting spring assembly 23 have the same structure, except that they differ in the tilting direction. Both include a tilting spring 31, a mounting base 32, and an adjusting base 33.

[0032] The mounting base 32 is used to fix the tilting spring 31. It includes a base 321 and a guide post 322. The guide post 322 and the central axis of the base 321 are on the same straight line, and the radial dimension of the guide post 322 is smaller than the radial dimension of the base 321, making room for the installation of the tilting spring 31. The tilting spring 31 is sleeved on the guide post 322 and abuts against the base 321. Preferably, the base 321 and the guide post 322 are integrally formed.

[0033] The adjusting base 33 is used to adjust the tilt angle of the tilting spring 31, and includes an ear plate 331, a pin 332, a fixed plate 333, a movable plate 334, and a torsion spring 335.

[0034] Two ear plates 331 are arranged at intervals relative to each other. The two ends of the pin 332 are respectively fixed to the two ear plates 331. The fixed plate 333 is fixed to the connecting plate 10 and located between the two ear plates 331. One end of the movable plate 334 is hinged to the fixed plate 333, and the other end is suspended. A torsion spring 335 is sleeved on the pin 332. One torsion arm of the torsion spring 335 abuts against the fixed plate 333, and the other torsion arm abuts against the suspended end of the movable plate 334. The base 321 is fixed to the movable plate 334. When the movable plate 334 rotates relative to the fixed plate 333, it drives the mounting base 32 and the tilting spring 31 thereon to rotate as a whole, changing the tilt angle of the tilting spring 31.

[0035] The connection between the fixed plate 333 and the movable plate 334 adopts a conventional form in the art. For example, both the fixed plate 333 and the movable plate 334 have curled sleeves at their ends, and a shaft passes through all the sleeves on both plates, allowing both the fixed plate 333 and the movable plate 334 to rotate around the shaft. In short, the mating structure of the fixed plate 333 and the movable plate 334 can be directly selected as a conventional hinge, with one leaf of the hinge fixed to the connecting plate 10 as the fixed plate 333, and the other leaf suspended as the movable plate 334.

[0036] Based on the rotatable nature of the movable plate 334 in the adjusting base 33, the tilt angles of the forward tilting spring assembly 22 and the reverse tilting spring assembly 23 can be adaptively adjusted according to the actual weight of the wind turbine 300, thereby adjusting the horizontal and vertical stiffness of the entire system. Depending on the angle, different quasi-zero stiffness vibration isolation ranges can be obtained, achieving optimal low-frequency vibration isolation performance while ensuring structural stability. This low-cost, low-interference adjustment method greatly improves adaptability to complex engineering environments.

[0037] By utilizing the axial contraction deformation of the central spring 211 and the inclined spring 31, vibration input energy can be absorbed, and horizontal and vertical vibrations can be isolated. This prevents the vibration generated by the wind turbine 300 from being effectively transmitted to the wooden tower 200, ensuring the stability of the wooden tower 200. Preferably, a rubber layer can also be wrapped around the central spring 211 and the inclined spring 31. The rubber itself provides damping for the system. Furthermore, because the rubber is wrapped around the spring, the spring utilizes its spatial arrangement to achieve nonlinearity; therefore, the rubber layer wrapped around the spring achieves nonlinear damping characteristics.

[0038] The vibration isolation support provided by this invention abandons the traditional vertical spring design, adopting a combination of inclined and vertical springs, with the vertical springs providing the main support. Based on the principle of force vector decomposition, the axial stiffness of the inclined spring can be decomposed into horizontal and vertical stiffness, ensuring vertical stiffness while significantly reducing the horizontal component stiffness, thereby greatly reducing the horizontal equivalent stiffness and achieving excellent horizontal vibration isolation effect. Meanwhile, the vertical stiffness of a traditional vertical spring is directly equal to its axial stiffness, resulting in extreme vertical rigidity and inability to isolate vertical vibrations. This invention, by setting the spring's tilt angle and utilizing geometric projection relationships, decomposes the axial stiffness of the inclined spring, allowing its vertical component to cooperate with the central spring to bear the load, making the vertical stiffness a controllable elastic parameter. The nonlinear stiffness characteristics of the inclined spring are adjusted by the angle-adjustable base, achieving quasi-zero stiffness characteristics in conjunction with the vertical spring. When vertical vibration exists, the spring assembly can absorb vertical impact energy through elastic expansion and contraction, significantly attenuating the vertical acceleration transmitted to the wooden tower 200. Thus, the present invention enables independent adjustment and on-site correction of horizontal and vertical stiffness, and has both efficient horizontal vibration isolation and vertical buffering capabilities.

[0039] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A nonlinear spring three-dimensional vibration isolation support for wooden wind turbine towers, characterized in that, include: Two spaced-apart connecting plates, one connected to the wind turbine and the other to the wooden tower structure; A spring system connecting the two connecting plates, the spring system comprising: The central spring assembly is located at the center of the connecting plate. A positively tilted spring assembly has its top end close to the top end of the central spring assembly and its bottom end far from the bottom end of the central spring assembly, forming a positively tilted state. The reverse tilting spring assembly has its top end away from the top end of the central spring assembly and its bottom end close to the bottom end of the central spring assembly, forming a reverse tilting state. There are multiple positive tilting spring assemblies and multiple negative tilting spring assemblies, which are evenly distributed around the central spring assembly.

2. The nonlinear spring three-dimensional vibration isolation support for wooden wind turbine towers according to claim 1, characterized in that, The two connecting plates are divided into an upper connecting plate and a lower connecting plate. The upper connecting plate is used to connect with the wind turbine, and the lower connecting plate is used to connect with the wooden tower. The upper connecting plate and the lower connecting plate are parallel and spaced apart.

3. The nonlinear spring three-dimensional vibration isolation support for wooden wind turbine towers according to claim 2, characterized in that, The central axes of the upper connecting plate, the lower connecting plate, and the central spring assembly are located on the same straight line.

4. The nonlinear spring three-dimensional vibration isolation support for wooden wind turbine towers according to claim 1, characterized in that, The number of positive tilt spring assemblies and negative tilt spring assemblies are both three, and the positive tilt spring assemblies and negative tilt spring assemblies are arranged alternately.

5. The nonlinear spring three-dimensional vibration isolation support for wooden wind turbine towers according to claim 1, characterized in that, The central spring assembly includes a central spring and two central spring seats disposed at both ends of the central spring for mounting the central spring; the central spring seat includes a central spring guide post and a central spring base disposed around the central spring guide post and spaced apart to form a mounting groove therebetween, and the end of the central spring is sleeved on the central spring guide post and confined within the mounting groove.

6. The nonlinear spring three-dimensional vibration isolation support for wooden wind turbine towers according to claim 5, characterized in that, The height of the central spring guide post is greater than the height of the central spring base.

7. The nonlinear spring three-dimensional vibration isolation support for wooden wind turbine towers according to claim 5, characterized in that, Both the forward tilting spring assembly and the reverse tilting spring assembly include a tilting spring, a mounting base, and an adjusting base. The mounting base is used to fix the end of the tilting spring, and the adjusting base is connected between the connecting plate and the mounting base. The adjusting base has an angle adjustment function to change the tilt angle of the tilting spring.

8. The nonlinear spring three-dimensional vibration isolation support for wooden wind turbine towers according to claim 7, characterized in that, The adjusting base includes ear plates, a pin, a fixed plate, a movable plate, and a torsion spring; the two ear plates are arranged relatively apart, the two ends of the pin are fixed to the two ear plates respectively, the fixed plate is fixed to the connecting plate and located between the two ear plates, one end of the movable plate is hinged to the fixed plate and the other end is suspended, the torsion spring is sleeved on the pin, and the two torsion arms of the torsion spring abut against the suspended ends of the fixed plate and the movable plate respectively; the mounting base is fixed to the movable plate.

9. The nonlinear spring three-dimensional vibration isolation support for wooden wind turbine towers according to claim 7, characterized in that, The mounting base includes a base and a guide post. The guide post and the central axis of the base are on the same straight line, and the radial dimension of the guide post is smaller than the radial dimension of the base. The tilting spring is sleeved on the guide post and abuts against the base.

10. The nonlinear spring three-dimensional vibration isolation support for wooden wind turbine towers according to claim 7, characterized in that, The central spring and the tilting spring are covered with a rubber layer.

Images