Variable centrifugal fly rod assembly and small wind turbine comprising same

Abstract

The utility model relates to a variable centrifugal fly rod assembly and a small wind turbine comprising the same, which comprise a centrifugal fly rod base, a centrifugal fly rod guide sleeve, a pre-tightening adjusting assembly, a linear bearing, a centrifugal fly rod guide rod with an end table at the inner end, a centrifugal fly rod spring and a fly rod counterweight sleeve sleeved at the outer end of the centrifugal fly rod guide rod, the centrifugal fly rod guide rod is sleeved with the centrifugal fly rod spring, the centrifugal fly rod spring is limited between the end table and the linear bearing and can be switched between an initial compression state and a re-compression state, and the centrifugal fly rod guide rod abuts against the pre-tightening adjusting assembly in the initial compression state; and after the rotating speed of the wind turbine impeller reaches a preset rotating speed, the centrifugal fly rod guide rod moves outwards to enable the centrifugal fly rod spring to enter a re-compressed state. The maximum rotating speed of the small wind turbine is reduced again, the service life of the generator, the main shaft brake and the like is prolonged, the small wind turbine can be compatible with a permanent magnet generator with higher voltage, the wind energy conversion efficiency of the whole machine is improved, the using amount of red copper and rare earth permanent magnets is reduced, and the production cost of the whole machine is reasonably reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of wind turbines, in particular to a variable centrifugal fly rod assembly and a small wind turbine comprising the same. Background Art

[0002] The overall economic efficiency of a wind turbine power generation system is determined by the overall energy efficiency. Large wind turbine main shafts typically utilize a speed-increasing gearbox, allowing the high-speed shaft to transmit energy to a high-speed permanent magnet generator (PMG). High-speed PMGs of equivalent power are significantly smaller than low-speed PMGs. The higher input speed allows the generator to generate higher potential energy, resulting in a higher output voltage. The formula for power and heat loss shows that higher voltage reduces the current density in the armature, and thus the electrical heat loss, resulting in a more efficient generator. This translates to: for equivalent efficiency and power, high-speed PMGs utilize fewer rare earth permanent magnets and use copper wire with a relatively smaller cross-section diameter. Currently, high-speed PMGs (i.e., PMGs with higher output voltages) are also common in large wind turbine systems. Given the significant price increases in both rare earth permanent magnets and copper, increasing generator efficiency and reducing costs is an inevitable trend.

[0003] Assuming the introduction of a more economical and efficient high-voltage permanent magnet generator into a small wind turbine (electrical component selection is based on voltage levels, so a 400ACV-rated generator requires conventional, universal components. This offers advantages in component procurement and maintenance, as components are common), small wind turbines lack the active regulation systems of large wind turbines and cannot operate at a constant speed, which would place considerable pressure on the electronic control system. With the applicant's current centrifugal pitch control technology, the wind turbine speed typically exceeds the rated speed by approximately 30% to 45% before the wind cut-out speed. Since the generator voltage is generally proportional to the wind turbine speed, if equipped with a 400ACV-rated permanent magnet generator, the generator voltage could reach 600ACV (AC voltage) under extreme conditions near the cut-out wind speed, and after rectification, it is estimated to be 810DCV (DC voltage). This voltage places considerable pressure on the electronic control system.

[0004] Currently, the small wind turbine platform constructed by the applicant using flying rod centrifugal pitch control technology (Patent No.: CN201821222785.7, Invention Title: Wind Turbine Safe Operation Control Device and Wind Turbine Incorporating Such Device) is not well suited to supporting high-voltage permanent magnet generators. Specifically, if a high-voltage permanent magnet generator is introduced into a small wind turbine, as shown in the above analysis, such a configuration will place significant pressure on the electrical control system under extreme wind speed conditions. Although the generator efficiency is improved and the cost is reduced, the electrical system requires the configuration of higher-voltage components. However, higher-voltage components are not readily available in the market, resulting in a significant increase in the cost of the electrical system.

[0005] To eliminate the above problems, enable the small wind turbine platform to well support high-voltage permanent magnet generators, and keep the cost of the wind turbine electronic control system under control, some technical means are needed to control the speed increase of the wind turbine before cutting out the wind speed to within 25%. The generator voltage may fluctuate to 500ACV, but after rectification, it is estimated to be within 675DCV, thereby ensuring the safety of the wind turbine's electronic control system. Utility Model Content

[0006] To overcome the above problems, the present invention provides a variable centrifugal fly rod assembly and a small wind turbine including the same, which will be advantageous so that the small wind turbine platform can well support a high-voltage permanent magnet generator.

[0007] The concept of the present invention is as follows: if the wind direction (i.e. the direction of the hub axis) is defined as the X-axis and the blade axis is pointed to as the Z-axis, then the other direction in the XYZ three-dimensional coordinate system is the Y-axis;

[0008] The core of pitch adjustment through centrifugal flying rod is to use the centrifugal force generated by the mass of the flying rod to generate a component on the Y axis to rotate the blades and thus achieve blade pitch adjustment. The angle of blade rotation affects the pitch adjustment effect.

[0009] The pre-compression force of the pitch spring at the beginning, i.e. the degree of compression in the pre-compression state, determines the starting speed of the pitch adjustment of the centrifugal fly rod;

[0010] A structure is set up so that the center of gravity position of the fly rod changes with the speed of the impeller. The starting speed of the fly rod center of gravity change is associated with the pre-compression force of the pitch spring to ensure that the pitch is not activated and the fly rod center of gravity adjustment is not activated when the wind turbine is at rated speed;

[0011] As the speed of the centrifugal flybar increases, its center of gravity moves further away from the impeller axis. This allows the centrifugal flybar to generate greater centrifugal force, which in turn accelerates the compression of the pitch spring. When the rated speed is exceeded and the variable flybar synchronous pitch mechanism is activated, a larger blade pitch angle can be achieved at the same speed. In this way, the blades deviate from the optimal working condition, and the impeller's ability to absorb wind energy, Cp, will decrease accordingly. The larger the pitch angle, the greater the decrease in Cp. The wind performs mechanical work on the impeller, and the generator converts the mechanical work into electrical energy. The wind turbine controller and electrical load regulate the wind turbine's electrical energy output to achieve a balance. As long as the wind speed does not change much, the impeller speed will reach a relatively stable state.

[0012] The above is the overall hook body concept of the present utility model.

[0013] To this end, according to one aspect of the utility model, a variable centrifugal fly rod assembly is provided, which includes a centrifugal fly rod base suitable for being installed on a blade assembly of a wind turbine, a centrifugal fly rod guide sleeve which is adjustably installed in the centrifugal fly rod base, a preload adjustment assembly which is adjustably installed in the inner end of the centrifugal fly rod guide sleeve, a linear bearing fixedly installed in the outer end of the centrifugal fly rod guide sleeve, a centrifugal fly rod guide rod which is slidably installed through the linear bearing, a centrifugal fly rod spring and a fly rod counterweight sleeve, wherein the inner end of the centrifugal fly rod guide rod is provided with an end platform, and the centrifugal fly rod spring is provided with a centrifugal fly rod spring. The fly rod spring is sleeved on the centrifugal fly rod guide rod and is limited between the end platform and the linear bearing. The fly rod counterweight sleeve is sleeved on the outer end of the centrifugal fly rod guide rod, and wherein the centrifugal fly rod spring is configured to be able to switch between an initial compression state and a re-compression state. In the initial compression state, the centrifugal fly rod guide rod is pressed against the preload adjustment component under the action force of the centrifugal fly rod spring; when the speed of the wind turbine impeller reaches a predetermined speed, the centrifugal fly rod guide rod moves outward with the fly rod counterweight sleeve, thereby further compressing the centrifugal fly rod spring and causing it to enter a re-compression state.

[0014] Furthermore, the centrifugal fly rod guide sleeve is threadedly fixed in the centrifugal fly rod base; the pre-tightening adjustment assembly includes a pre-tightening adjustment nut and a pre-tightening adjustment screw, the pre-tightening adjustment nut is threadedly installed in the inner end of the centrifugal fly rod guide sleeve, the pre-tightening adjustment screw passes through the pre-tightening adjustment nut in the inner end of the centrifugal fly rod guide sleeve and cooperates with the pre-tightening adjustment nut thread, and in the initial compression state, the outer end of the pre-tightening adjustment screw presses against the centrifugal fly rod guide rod.

[0015] Furthermore, an end platform is provided in the centrifugal fly rod guide sleeve, and the centrifugal fly rod spring and the linear bearing are respectively located on the inner and outer sides of the end platform, and the centrifugal fly rod spring is limited between the end platform of the centrifugal fly rod guide rod and the end platform of the centrifugal fly rod guide sleeve; the predetermined speed is greater than the rated speed of the wind turbine.

[0016] According to another aspect of the present invention, a small wind turbine is provided, comprising an impeller having a hub and a plurality of blade assemblies, a variable flybar synchronous pitch mechanism mounted on the impeller, and a nacelle with a built-in generator, wherein:

[0017] The generator is a high voltage permanent magnet generator;

[0018] The variable fly rod synchronous pitch mechanism includes the above-mentioned variable centrifugal fly rod assembly, wherein the number of the variable centrifugal fly rod assemblies corresponds one-to-one to the number of the plurality of blade assemblies.

[0019] Furthermore, each blade assembly includes a blade stalk fixedly mounted on the hub, a blade stalk flange rotatably mounted on the blade stalk, and a blade fixedly mounted on the blade stalk flange, wherein the centrifugal fly rod base of the variable centrifugal fly rod assembly is fixedly mounted on the blade stalk flange.

[0020] Furthermore, each blade assembly also includes a bearing A, a bearing B and a fastener, wherein the outer rings of bearing A and bearing B are fixedly mounted on the petiole flange and the inner rings are fixed on the petiole shaft, and the fastener is threadedly mounted on the outer end of the petiole shaft and abuts against the outer end face of the inner ring of bearing B.

[0021] Furthermore, bearing A and bearing B are both tapered bearings and are spaced back to back.

[0022] Furthermore, the variable flying rod synchronous pitch mechanism also includes a guide shaft with an inner end annular shoulder, a pitch spring, a synchronous disk, a synchronous disk guide sleeve with an outer end annular shoulder, a pitch spring pre-tightening nut, a pull rod corresponding to each blade assembly and ball bearings installed on both ends of each pull rod, wherein the guide shaft is coaxially fixed to the wheel hub, the synchronous disk is axially movably sleeved on the synchronous disk guide sleeve on the inner side of the outer end annular shoulder, the synchronous disk guide sleeve is sleeved on the guide shaft, the pitch spring pre-tightening nut is threadedly installed on the guide shaft and presses inward against the outer end annular shoulder of the synchronous disk guide sleeve, the pitch spring is sleeved on the guide shaft and limited between the inner end annular shoulder of the guide shaft and the synchronous disk, and one of the ball bearings at both ends of the pull rod is rotatably connected to the synchronous disk, and the other ball bearing is rotatably connected to the blade stalk flange.

[0023] Furthermore, the synchronizing disk is provided with a guide key, and correspondingly, the synchronizing disk guide sleeve is provided with a guide key slot. The synchronizing disk can move axially on the synchronizing disk guide sleeve through the cooperation of the guide key and the guide key slot.

[0024] Furthermore, the variable flying rod synchronous pitch mechanism also includes a fairing, which is threadably mounted in the guide shaft via a fixing bolt at its outermost end.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1) The variable centrifugal flybar assembly significantly improves the ability of small wind turbines to adjust their speed using the centrifugal flybar, further reducing the maximum speed of the small wind turbine, indirectly extending the service life of the generator (such as bearings and other components) and the main shaft brake (because the lower the maximum speed of the wind turbine, the smaller the rotational kinetic energy of the impeller, and the less impact on the main shaft during the wind turbine main shaft braking).

[0027] 2) The design of the variable centrifugal flybar assembly enables it to be used in all wind turbines based on the centrifugal flybar variable pitch structure platform. This allows this small wind turbine product line to be compatible with higher voltage permanent magnet generators, thereby improving the wind energy conversion efficiency of the entire machine, reducing the amount of copper and rare earth permanent magnets used, and reasonably reducing the production cost of the entire machine, making the product more competitive in the market.

[0028] 3) The design of the variable centrifugal flybar assembly enables small wind turbine products to more easily adapt to complex environments through their mechanical structure. It can also mitigate the impact on the electrical control system in harsh climatic conditions such as islands, offshore sightseeing or aquaculture platforms, Antarctica, and frontier areas with abundant wind resources, further improving the survivability of the wind turbine's mechanical structure and electrical system.

[0029] These and other aspects of the present invention will be more clearly explained with reference to the embodiments described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The structure and further objects and advantages of the present invention will be better understood through the following description in conjunction with the accompanying drawings, in which like reference numerals identify like elements:

[0031] Figure 1 It is a partial three-dimensional schematic diagram of a small wind turbine according to a specific embodiment of the present utility model;

[0032] Figure 2 is a partial three-dimensional schematic diagram of the small wind turbine according to this specific embodiment of the utility model from another angle;

[0033] Figure 3 yes Figure 1 A schematic cross-sectional view of one of the blade assemblies of the small wind turbine shown is a longitudinal cross-sectional view of the variable centrifugal flybar assembly thereof;

[0034] Figure 4 yes Figure 1 A perspective exploded schematic diagram of one of the blade assemblies of the small wind turbine exploded from its variable centrifugal flybar assembly;

[0035] Figure 5 yes Figure 1A partial cross-sectional schematic diagram of one of the blade assemblies of the small wind turbine shown in FIG.

[0036] Figure 6 yes Figure 1 A cross-sectional schematic diagram of the variable flying rod synchronous pitch mechanism of the small wind turbine shown (the guide cover is retained). DETAILED DESCRIPTION

[0037] Specific embodiments of the present invention will be described below with reference to the accompanying drawings. However, it should be understood that the embodiments disclosed herein are merely typical examples of the present invention, which may be embodied in various forms. Therefore, the specific details disclosed herein are not to be construed as limiting, but merely as a basis for the claims and as a representative basis for teaching those skilled in the art to apply the present invention in various practical and appropriate ways.

[0038] like Figures 1 to 6 As shown, a small wind turbine according to a specific embodiment of the present invention includes an impeller 100 having multiple blade assemblies 10 and a hub 11, a variable fly rod synchronous pitch mechanism 300 installed on the impeller 100, and a nacelle with a built-in generator (not shown in the figure), wherein, in this embodiment, the generator is a high-voltage permanent magnet generator; the variable fly rod synchronous pitch mechanism 300 includes variable centrifugal fly rod assemblies 500, the number of which corresponds one-to-one to the number of the multiple blade assemblies.

[0039] like Figure 3 and Figure 4 As shown, and reference Figure 1 and Figure 2In this embodiment, the variable centrifugal fly rod assembly 500 includes a centrifugal fly rod base 51 suitable for installation on the blade assembly 10 of the wind turbine, a centrifugal fly rod guide sleeve 53 that is adjustably installed in the centrifugal fly rod base 51, a preload adjustment assembly that is adjustably installed in the inner end of the centrifugal fly rod guide sleeve 53, a linear bearing 55 fixedly installed in the outer end of the centrifugal fly rod guide sleeve 53, a centrifugal fly rod guide rod 57 that is slidably installed through the linear bearing 55, a centrifugal fly rod spring 58 and a fly rod counterweight sleeve 59, wherein the inner end of the centrifugal fly rod guide rod 57 is provided with an end platform 570, and the centrifugal fly rod spring 58 is sleeved on the centrifugal fly rod guide rod 57 and limited. Between the end platform 570 and the linear bearing 55, a flybar counterweight sleeve 59 is mounted on the outer end of the centrifugal flybar guide rod 57. A centrifugal flybar spring 58 is configured to switch between an initial compressed state and a re-compressed state. In the initial compressed state, the centrifugal flybar guide rod 57 presses against the preload adjustment assembly under the force (i.e., the restoring force) of the centrifugal flybar spring 58. When the speed of the wind turbine impeller 100 reaches a predetermined speed, i.e., when the centrifugal force of the variable centrifugal flybar assembly 500 reaches a certain level, the centrifugal flybar guide rod 57 moves outward with the flybar counterweight sleeve 59, further compressing the centrifugal flybar spring 58 and causing it to enter a re-compressed state. It should be noted that the predetermined speed is greater than the rated speed of the wind turbine.

[0040] Preferably, if Figure 3 As shown, in this embodiment, an end platform 530 is provided in the centrifugal fly rod guide sleeve 53, and the centrifugal fly rod spring 58 and the linear bearing 55 are respectively located on the inner and outer sides of the end platform 530, and the centrifugal fly rod spring 58 is limited between the end platform 570 of the centrifugal fly rod guide rod 57 (one end position of the centrifugal fly rod spring 58 located at the end platform is movable) and the end platform 530 of the centrifugal fly rod guide sleeve 53 (one end position of the centrifugal fly rod spring 58 located at the end platform is fixed), so that in the process of the centrifugal fly rod guide rod 57 moving outward with the fly rod counterweight sleeve 59, the centrifugal fly rod spring 58 is pushed outward by the end platform 570 of the centrifugal fly rod guide rod 57 for further compression.

[0041] like Figure 3 and Figure 4As shown, in this embodiment, the centrifugal fly rod guide sleeve 53 is threadedly fixed in the centrifugal fly rod base 51, and the fixing depth can be flexibly adjusted to improve adjustability; the above-mentioned pre-tightening adjustment component includes a pre-tightening adjustment nut 52 and a pre-tightening adjustment screw 54, the pre-tightening adjustment nut 52 (with a screw hole in the center and an external thread on the outer circle) is threadedly installed in the inner end of the centrifugal fly rod guide sleeve 53 (the inner end of the centrifugal fly rod guide sleeve 53 is provided with an internal thread), the pre-tightening adjustment screw 54 is installed in the inner end of the centrifugal fly rod guide sleeve 53 (the left end in the figure is the inner end) and is threadedly engaged with the pre-tightening adjustment nut 52, and in the initial compression state, the outer end of the pre-tightening adjustment screw 54 (the right end in the figure is the outer end) presses against the centrifugal fly rod guide rod 57 to prevent the centrifugal fly rod guide rod 57 from moving inward under the action of the centrifugal fly rod spring 58 and causing the centrifugal fly rod spring 58 to break away from its initial compression state.

[0042] like Figures 1 to 5 As shown, in this embodiment, each blade assembly 10 includes a stalk shaft 12 fixedly mounted on the hub 11, a stalk flange 14 rotatably mounted on the stalk shaft 12, and a blade 16 fixedly mounted on the stalk flange 14, wherein the centrifugal fly rod base 51 of the variable centrifugal fly rod assembly 500 is fixedly mounted on the stalk flange 14.

[0043] For example Figure 5 As shown, each blade assembly 10 also includes a bearing A13, a bearing B15, and a fastener 17. The outer rings of bearings A13 and B15 are fixedly mounted on the blade flange 14, and their inner rings are fixed to the blade shaft 12. The fastener 17 is threaded onto the outer end of the blade shaft 12 and abuts against the outer end surface of the inner ring of bearing B15. In this embodiment, bearings A13 and B15 are tapered bearings and are spaced back-to-back. Specifically, bearings A13 and B15 are respectively mounted in the bearing holes at both ends of the blade flange 14. The blade shaft 12 passes through bearings A13 and B15 and is fixed to their inner rings.

[0044] like Figure 6 As shown, and reference Figure 1 and Figure 2In this embodiment, the variable flying rod synchronous pitch mechanism 300 also includes a synchronization disk 31, a guide shaft 32, a synchronization disk guide sleeve 33, a pitch spring 34, a pitch spring pre-tightening nut 36, a pull rod 38 corresponding to each blade assembly 10, and a ball head bearing 39 installed on both ends of each pull rod 38. Among them, the guide shaft 32 is coaxially fixed on the wheel hub 11, and an inner end annular shoulder 320 is provided on it; the synchronous disk guide sleeve 33 has an outer end annular shoulder 330, the synchronous disk 31 is sleeved on the synchronous disk guide sleeve 33 and is located on the inner side of its outer end annular shoulder 330, and the synchronous disk guide sleeve 33 is sleeved on the guide shaft 32; the pitch spring pre-tightening nut 36 is threadedly installed on the guide shaft 32 and presses inward against the outer end annular shoulder 330 of the synchronous disk guide sleeve 33, the pitch spring 34 is sleeved on the guide shaft 32 and limited between the inner end annular shoulder 320 of the guide shaft 32 and the synchronous disk 31 in a pre-compression state, and one of the ball bearings 39 at both ends of the pull rod 38 is rotatably connected to the synchronous disk 31, and the other ball bearing 39 is rotatably connected to the blade stalk flange 14.

[0045] like Figure 6 As shown, in this embodiment, a guide key (not shown) is provided on the synchronization disk 31, and correspondingly, a guide key groove (not shown) is provided on the synchronization disk guide sleeve 33. The synchronization disk 31 can move axially on the synchronization disk guide sleeve 33 through the cooperation of the guide key and the guide key groove, thereby compressing or releasing the pitch spring 34.

[0046] For example Figure 6 As shown, in this embodiment, the one ball bearing 39 is rotatably connected to the synchronizing disk 31 via a pin 390 , and the other ball bearing 39 is rotatably connected to the blade stalk flange 14 via a pin (not shown).

[0047] For example Figure 6 As shown, in this embodiment, the variable flying rod synchronous pitch mechanism 300 further includes a deflector 35, which is threadedly mounted in the guide shaft 32 via a fixing bolt 37 at its outermost end. In addition, it should be noted that for the sake of clarity, the deflector 35 is schematically shown in FIG. Figure 1 and Figure 2 has been removed, and for clarity, Figure 1 and Figure 2 The structure of the synchronous disc guide sleeve 33 is also removed.

[0048] In addition, if Figure 2As clearly shown, in this embodiment, a lug structure 140 is provided on the petiole flange 14, and a ball bearing 39 is rotatably mounted on the lug structure 140 and connected to one end of the pull rod 38; the ball bearing 39 on the other end of the pull rod 38 is rotatably mounted on the synchronous disk 31 by means of a pin shaft 390, so that when the blade assembly 10 rotates and changes pitch under the centrifugal force of the variable centrifugal fly rod assembly 500, the synchronous disk 31 moves axially along the synchronous disk guide sleeve 33 and the guide shaft 32 under the drive of the pull rod 38, thereby compressing the pitch spring 34 inward.

[0049] The present invention will be further described below from two aspects: mechanism motion and mechanism mechanism.

[0050] Mechanism motion description:

[0051] If the wind direction is defined as the X-axis direction (i.e. the direction of the hub axis, toward the right, see Figure 1 ), the axial direction of the blade 16 is the Z axis, and the other direction in the XYZ three-dimensional coordinate system is the Y axis (i.e. Figure 1 direction perpendicular to the paper);

[0052] The first main line of movement: When the variable centrifugal fly rod assembly 500 rotates with the impeller 100, the mass of the variable centrifugal fly rod assembly 500 generates centrifugal force. The component of the centrifugal force generated on the Y axis eventually generates a torque relative to the axis of the petiole flange 14 under the action of the distance between the center of mass of the variable centrifugal fly rod assembly 500 and the axis of the blade stalk flange 14, causing the blade stalk flange 14 to rotate around the blade stalk axis 12. The blade stalk flange 14 acts on the ball bearing 39 and pulls the pull rod 38. The pull rod 38 acts on the synchronous disk 31 through the ball bearing 39 at the other end. The synchronous disk 31 moves inward along the synchronous disk guide sleeve 33, while compressing the pre-tightened variable pitch spring 34. It should be understood that there is a certain mathematical relationship between the rotational speed of the impeller 100 and the spring compression of the pitch spring 34: when the rotational speed of the impeller 100 exceeds a predetermined value, that is, the predetermined rotational speed, the pitch spring 34 is further compressed, and the blades 16 pitch. During the pitching process, the ability of the impeller 100 to absorb wind energy decreases, resulting in a decrease in the rotational speed of the impeller 100 and a slowing down of the pitching trend of the blades 16. At the same time, when the blades 16 pitch to a certain value, that is, the pitch spring 34 is compressed to a certain extent, and at the same time, when the rotational speed of the impeller 100 drops to a certain value, the rotational speed of the impeller 100 and the spring compression of the pitch spring 34 are balanced again.

[0053] The second main line of motion: The variable centrifugal fly rod assembly 500 is mounted on the blade stalk flange 14. In the XZ plane, the variable centrifugal fly rod assembly 500 is arranged at an angle to the blade stalk flange 14 (the K coefficient of the centrifugal fly rod spring 12.5 is related to the size of the angle). As the variable centrifugal fly rod assembly 500 rotates with the impeller 100, the mass of the variable centrifugal fly rod assembly 500 generates centrifugal force. The component of this centrifugal force generated in the Z axis is further transmitted and decomposed inside the variable centrifugal fly rod assembly 500. As a result of the transmission, the centrifugal fly rod guide rod 57 and the fly rod counterweight sleeve 59 move. Specifically, most of the work generated by the component of the centrifugal force in the Z axis will be stored in the centrifugal fly rod spring 58, and some of the energy will be decomposed into friction loss in the linear bearing 55 and the preload adjustment screw 54. In other words, the component of the centrifugal force generated in the Z axis is decomposed into axial force and radial force. The axial force is used for transmission, and part of the radial force is eventually absorbed by the hub 11 due to the presence of the fixed components (the centrifugal fly rod base 51 inside the variable centrifugal fly rod assembly 500). , the preload adjustment screw 54, the preload adjustment nut 52, the centrifugal fly rod spring 58 and the linear bearing 55 are all fixed parts, and the Z-axis components generated by these parts are ultimately absorbed by the petiole flange 14, the petiole shaft 12 and the hub 11), and the other part becomes friction loss due to the presence of movable parts (the centrifugal force of the movable parts such as the centrifugal fly rod guide rod 57 and the fly rod counterweight sleeve 59 inside the variable centrifugal fly rod assembly 500 is decomposed into the radial component of the centrifugal fly rod guide rod 57, which reacts with the linear bearing 55 to generate friction resistance, and the centrifugal force of these movable parts is decomposed into the axial component of the centrifugal fly rod guide rod 57 to overcome the friction resistance of the linear bearing 55, and to compress the pre-loaded centrifugal fly rod spring 58, wherein the axial component of the centrifugal fly rod guide rod 57 into which the component generated by the Z-axis is decomposed, and the elastic force from the centrifugal fly rod spring 58 and the friction force from the linear bearing 55 are balanced).

[0054] Mechanism description:

[0055] The formula for calculating centrifugal force is F=mω^2r (i.e. F=m*ω^2*r), where F is the centrifugal force, m is the mass, ω is the rotational speed, and r is the distance from the center of mass to the axis of rotation;

[0056] The core of the centrifugal fly bar pitch adjustment is to use the centrifugal force generated by the mass of the fly bar to generate a component on the Y axis to rotate the blades. The centrifugal force calculation formula shows that once the product structure, i.e., the centrifugal fly bar, is formed, its mass parameter m basically does not change. The centrifugal fly bar ultimately adjusts (or balances) the speed parameter ω, that is, the ω parameter is our ultimate control target.

[0057] In the present invention, the variable centrifugal flybar assembly 500 increases the flybar centrifugal force by simply changing the center of mass position (corresponding to the parameter r in the centrifugal force calculation formula). Since the center of mass change is also related to ω^2, the parameter r can be expressed as r(ω^2) (the expression r(ω^2) indicates that r has a direct mathematical relationship with the rotational speed ω^2). As the rotational speed increases, r also increases. As can be seen from the centrifugal force calculation formula F=mω^2r, the centrifugal force F also increases, allowing the blades 16 to rotate to achieve variable pitch, thereby reducing the rotational speed, and thus the centrifugal force, and r also decreases.

[0058] Assuming the rated speed of the wind turbine impeller 100 is ω0, after the pitch spring 34 is pre-compressed, the variable centrifugal fly rod assembly 500 needs to be at ω1 to activate the variable fly rod synchronous pitch mechanism 300 to compress the pitch spring 34 again. Note that at this time, the centrifugal fly rod spring 58 is also in the pre-compressed state, that is, it has not reached the activated state.

[0059] When the rotation speed of the impeller 100 continues to increase slightly and reaches ω2, the centrifugal force of the movable parts such as the centrifugal fly rod guide rod 57 and the fly rod counterweight sleeve 59 inside the variable centrifugal fly rod assembly 500 is decomposed into an axial component of the centrifugal fly rod guide rod 57, and the axial component of the centrifugal fly rod guide rod 57 = the preload of the preloaded centrifugal fly rod spring 58 + the friction resistance generated by the action of the centrifugal fly rod guide rod 57 and the linear bearing 55;

[0060] When the speed of the impeller 100 continues to increase slightly, the centrifugal force of the movable parts such as the centrifugal fly rod guide rod 57 and the fly rod counterweight sleeve 59 inside the variable centrifugal fly rod assembly 500 produces a component decomposition in the Z axis, which increases the axial component of the centrifugal fly rod guide rod 57, which inevitably causes the centrifugal fly rod guide rod 57 and the fly rod counterweight sleeve 59 to move, changing the center of mass of the variable centrifugal fly rod assembly 500 and causing r to change in the increasing direction;

[0061] Under the same rotational speed conditions, the center of mass position of the fixed fly rod assembly is unchanged, but the center of mass position r of the variable centrifugal fly rod assembly 500 increases as the rotational speed increases. The center of mass position of the variable centrifugal fly rod assembly 500 conforms to the expression r(ω^2). The above-mentioned centrifugal force calculation formula is F=m*ω^2*r, so the centrifugal force calculation formula of the variable centrifugal fly rod assembly 500 can be changed to F=m*ω^2*r(ω^2). In other words, the centrifugal force of the variable centrifugal fly rod assembly 500 is more sensitive to the rotational speed parameter ω than the centrifugal force of the fixed fly rod assembly. Under the same rotational speed conditions, the variable centrifugal fly rod assembly 500 is more likely to obtain a larger centrifugal force. The component generated on the Y-axis by the larger centrifugal force is more likely to drive the petiole flange 14 to rotate.

[0062] It can be seen from the above-mentioned "first main line of operation" that the centrifugal force generates a component on the Y-axis and is eventually transmitted to the synchronization disk 31 to compress the pitch spring 34, that is, the pitch spring 34 can be compressed more and reach a balance, and the blades 16 fixed on the blade stalk flange 14 can also obtain more angle adjustment, so that the blades 16 are out of the optimal working condition, and the Cp value of the impeller 100's ability to absorb wind energy will decrease accordingly. The larger the pitch angle, the more the Cp value decreases. The wind does mechanical work on the impeller 100, and the generator converts the mechanical work into electrical energy. The wind turbine controller and the electrical load adjust the wind turbine's electrical energy output to achieve a balance. As long as the wind speed does not change much, the wind rotor speed will reach a relatively stable state.

[0063] The technical content and technical features of the present invention have been disclosed above. However, it is understood that, based on the creative ideas of the present invention, those skilled in the art may make various changes and improvements to the above structure, including combinations of the technical features disclosed or claimed herein, as well as other combinations that clearly include these features. Such variations and / or combinations fall within the technical field involved in the present invention and fall within the scope of protection of the claims of the present invention.

Claims

1. A variable centrifugal fly rod assembly, characterized in that The invention comprises a centrifugal fly rod base suitable for being installed on the blade assembly of a wind turbine, a centrifugal fly rod guide sleeve which is adjustably installed in the centrifugal fly rod base, a preload adjustment assembly which is adjustably installed in the inner end of the centrifugal fly rod guide sleeve, a linear bearing which is fixedly installed in the outer end of the centrifugal fly rod guide sleeve, a centrifugal fly rod guide rod which is slidably installed through the linear bearing, a centrifugal fly rod spring and a fly rod counterweight sleeve, wherein the inner end of the centrifugal fly rod guide rod is provided with an end platform, the centrifugal fly rod spring is sleeved on the centrifugal fly rod guide rod and limited between the end platform and the linear bearing, the fly rod counterweight sleeve is sleeved on the outer end of the centrifugal fly rod guide rod, and wherein the centrifugal fly rod spring is configured to be able to switch between an initial compression state and a recompression state, and in the initial compression state, the centrifugal fly rod guide rod is pressed against the preload adjustment assembly under the action force of the centrifugal fly rod spring; when the speed of the wind turbine impeller reaches a predetermined speed, the centrifugal fly rod guide rod moves outward with the fly rod counterweight sleeve, thereby further compressing the centrifugal fly rod spring and causing it to enter a recompression state.

2. The variable centrifugal fly rod assembly according to claim 1, characterized in that: The centrifugal fly rod guide sleeve is threadedly fixed in the centrifugal fly rod base; the pre-tightening adjustment assembly includes a pre-tightening adjustment nut and a pre-tightening adjustment screw, the pre-tightening adjustment nut is threadedly installed in the inner end of the centrifugal fly rod guide sleeve, the pre-tightening adjustment screw passes through the pre-tightening adjustment nut in the inner end of the centrifugal fly rod guide sleeve and cooperates with the pre-tightening adjustment nut thread, and in the initial compression state, the outer end of the pre-tightening adjustment screw presses against the centrifugal fly rod guide rod.

3. The variable centrifugal fly rod assembly according to claim 1, characterized in that: An end platform is provided in the centrifugal fly rod guide sleeve, the centrifugal fly rod spring and the linear bearing are respectively located on the inner and outer sides of the end platform, and the centrifugal fly rod spring is limited between the end platform of the centrifugal fly rod guide rod and the end platform of the centrifugal fly rod guide sleeve; the predetermined speed is greater than the rated speed of the wind turbine.

4. A small wind turbine comprising an impeller having a hub and a plurality of blade assemblies, a variable flybar synchronous pitch mechanism mounted on the impeller, and a nacelle with a built-in generator, characterized in that: The generator is a high voltage permanent magnet generator; The variable fly rod synchronous pitch mechanism comprises the variable centrifugal fly rod assembly according to any one of claims 1 to 3, wherein the number of the variable centrifugal fly rod assemblies corresponds one-to-one to the number of the plurality of blade assemblies.

5. The small wind turbine according to claim 4, characterized in that: Each of the blade assemblies includes a blade stalk fixedly mounted on the hub, a blade stalk flange rotatably mounted on the blade stalk, and a blade fixedly mounted on the blade stalk flange, wherein the centrifugal fly rod base of the variable centrifugal fly rod assembly is fixedly mounted on the blade stalk flange.

6. The small wind turbine according to claim 5, characterized in that: Each of the blade assemblies further includes a bearing A, a bearing B and a fastener, wherein the outer rings of the bearing A and the bearing B are fixedly mounted on the petiole flange and the inner rings are fixed on the petiole shaft, and the fastener is threadedly mounted on the outer end of the petiole shaft and abuts against the outer end surface of the inner ring of the bearing B.

7. The small wind turbine according to claim 6, characterized in that: The bearing A and the bearing B are both tapered bearings and are spaced back to back.

8. The small wind turbine according to claim 5, characterized in that: The variable flying rod synchronous pitch mechanism also includes a guide shaft with an inner end annular shoulder, a pitch spring, a synchronous disk, a synchronous disk guide sleeve with an outer end annular shoulder, a pitch spring pre-tightening nut, a pull rod corresponding to each of the blade assemblies and a ball bearing mounted on both ends of each pull rod, wherein the guide shaft is coaxially fixed to the wheel hub, the synchronous disk is axially movably sleeved on the synchronous disk guide sleeve on the inner side of the outer end annular shoulder, the synchronous disk guide sleeve is sleeved on the guide shaft, the pitch spring pre-tightening nut is threadedly installed on the guide shaft and presses inward against the outer end annular shoulder of the synchronous disk guide sleeve, the pitch spring is sleeved on the guide shaft and limited between the inner end annular shoulder of the guide shaft and the synchronous disk, one of the ball bearings at both ends of the pull rod is rotatably connected to the synchronous disk, and the other ball bearing is rotatably connected to the blade stalk flange.

9. The small wind turbine according to claim 8, characterized in that: The synchronizing disk is provided with a guide key, and correspondingly, the synchronizing disk guide sleeve is provided with a guide key slot. The synchronizing disk can move axially on the synchronizing disk guide sleeve through the cooperation of the guide key and the guide key slot.

10. The small wind turbine according to claim 9, characterized in that: The variable flying rod synchronous pitch mechanism also includes a fairing, which is threadably mounted in the guide shaft at its outermost end via a fixing bolt.

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