Variable centrifugal fly rod assembly and small wind turbine comprising same

Abstract

The variable centrifugal fly rod assembly comprises 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 arranged at the inner end, a centrifugal fly rod spring and a fly rod balance weight sleeve arranged at the outer end of the centrifugal fly rod guide rod in a sleeving mode. 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 present invention relates to the technical field of wind turbine generators, and 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 the wind turbine power generation system is determined by the energy efficiency of the whole machine. The main shaft of a large wind turbine generally uses a speed-increasing gearbox to allow the high-speed shaft to transmit energy to the high-speed permanent magnet generator. The volume of a high-speed permanent magnet generator of the same power is much smaller than that of a low-speed permanent magnet generator. The input of high speed can enable the generator to obtain higher potential energy, that is, output a higher voltage. From the formula of power and heat consumption, it can be known that the higher the voltage, the smaller the current density in the armature, and the electric heat consumption will also become smaller, that is, it is easy to get a relatively efficient generator. It can be understood that: under the same efficiency and the same power, the high-speed permanent magnet generator invests less rare earth permanent magnets and uses relatively small cross-sectional diameter copper wire. At present, high-speed permanent magnet generators, that is, permanent magnet generators with higher output voltages, are also very common in large wind turbine generator systems. Since the current market prices of rare earth permanent magnets and copper have risen a lot, it is an inevitable trend to increase the efficiency and reduce the cost of generators.

[0003] Assuming that a more economical and efficient high-voltage permanent magnet generator is introduced into a small wind turbine (the selection of electrical components is based on the voltage level, so the electrified components of the generator rated at 400ACV are also conventional general series, so that the product components procurement, maintenance, etc. have advantages, and components are currency), since small wind turbines do not have the active adjustment system of large wind turbines, they cannot operate at a constant speed, which will bring greater pressure to the electronic control system. In terms of the applicant's current centrifugal pitch technology, before the wind speed is cut out, the wind turbine speed usually exceeds the rated speed by about 30% to 45%; and the generator voltage is basically proportional to the wind turbine speed. If a permanent magnet generator rated at 400ACV is configured, the wind turbine is under extreme conditions close to the cut-out wind speed. The generator voltage may float to 600ACV (AC voltage), and after rectification, it is estimated to be 810DCV (DC voltage). This voltage is relatively stressful for the electronic control system.

[0004] At present, the small wind turbine platform constructed by the applicant through the flying rod centrifugal pitch technology (patent number: CN201821222785.7, invention name: wind turbine safe operation control device and wind turbine containing the device) cannot well support high-voltage permanent magnet generators. Specifically, if a high-voltage permanent magnet generator is introduced into a small wind turbine, it can be seen from the above analysis that such a configuration will put great pressure on the electrical control under extreme wind speed conditions. Although the efficiency of the generator is improved and the cost is reduced, the electrical aspect needs to be configured with higher voltage components, and higher voltage components are not the currency of the market, so the supporting cost of the electrical system has increased significantly.

[0005] In order to eliminate the above problems and 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 voltage of the generator may float to 500ACV but is estimated to be within 675DCV after rectification, thereby ensuring the safety of the wind turbine's electronic control system. Summary of the invention

[0006] In order 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 hub axis direction) is defined as the X-axis direction, and the blade axis direction is the Z-axis, then the other direction in the XYZ three-dimensional coordinate system is the Y-axis; The core of pitch adjustment by 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 achieve blade pitch adjustment. The angle of blade rotation affects the pitch adjustment effect. 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 flying rod; A structure is set so that the center of gravity position of the flying rod will change with the speed of the impeller. The starting speed of the flying rod center of gravity change is associated with the pre-compression force of the pitch spring to ensure that the pitch is not started at the rated speed of the wind turbine and the flying rod center of gravity adjustment is not started; As the speed of the centrifugal fly bar increases, its center of gravity will be further away from the impeller axis, so that the centrifugal fly bar can obtain greater centrifugal force, thereby accelerating the compression of the pitch spring. When the rated speed is exceeded and the variable fly bar synchronous pitch mechanism is activated, a larger blade pitch angle can be obtained under the same speed conditions. In this way, the blades are out of the optimal working condition, and the impeller's ability to absorb wind energy Cp value will decrease accordingly. The larger the pitch angle, the more Cp decreases. The wind does mechanical work on the impeller, the generator converts the mechanical work into electrical energy, and the wind turbine controller and 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 impeller speed will reach a relatively stable state.

[0008] The above is the overall hook body concept of the present invention.

[0009] To this end, according to one aspect of the present invention, 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 table, and the centrifugal fly rod is provided with a centrifugal fly rod spring. The 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 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.

[0010] Furthermore, the centrifugal fly rod guide sleeve is threadedly fixed in the centrifugal fly rod base; the preload adjustment assembly includes a preload adjustment nut and a preload adjustment screw, the preload adjustment nut is threadedly installed in the inner end of the centrifugal fly rod guide sleeve, the preload adjustment screw passes through the preload adjustment nut in the inner end of the centrifugal fly rod guide sleeve and cooperates with the preload adjustment nut thread, and in the initial compression state, the outer end of the preload adjustment screw presses against the centrifugal fly rod guide rod.

[0011] 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.

[0012] According to another aspect of the present invention, there is provided a small wind turbine, comprising an impeller having a hub and a plurality of blade assemblies, a variable flying rod synchronous pitch mechanism mounted on the impeller, and a nacelle with a built-in generator, wherein: The generator is a high voltage permanent magnet generator; The variable flying rod synchronous pitch mechanism comprises the above-mentioned variable centrifugal flying rod assembly, wherein the number of the variable centrifugal flying rod assembly corresponds one-to-one to the number of the plurality of blade assemblies.

[0013] 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.

[0014] 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.

[0015] Furthermore, bearing A and bearing B are both tapered bearings and are spaced back to back.

[0016] 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 petiole flange.

[0017] Furthermore, a guide key is provided on the synchronization disk, and correspondingly, a guide key slot is provided on the synchronization disk guide sleeve. The synchronization disk can move axially on the synchronization disk guide sleeve through the cooperation of the guide key and the guide key slot.

[0018] Furthermore, the variable flying rod synchronous pitch mechanism also includes a fairing, which is threadably mounted in the guide shaft via fixing bolts at its outermost end.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1) The setting of the variable centrifugal fly rod assembly significantly improves the ability of small wind turbines to adjust the speed using the centrifugal fly rod, which can further reduce the maximum speed of small wind turbines, indirectly increase the service life of the generator (such as bearings and other components), and at the same time increase the service life of the main shaft brake (because the maximum speed of the wind turbine is small, the rotational kinetic energy of the impeller is also small, and the impact on the main shaft of the wind turbine when braking is also reduced); 2) The design of the variable centrifugal fly bar assembly enables the use of wind turbines based on the centrifugal fly bar variable pitch structure platform, thereby making this type of small wind turbine product series compatible with higher voltage permanent magnet generators, thereby improving the wind energy conversion efficiency of the whole machine, reducing the amount of copper and rare earth permanent magnets, and reasonably reducing the production cost of the whole machine, making the product more competitive in the market; 3) The design of the variable centrifugal fly rod assembly enables small wind turbine products to adapt to complex environments more easily through mechanical structure. It can also reduce the impact on the electrical control system under harsh climatic conditions such as islands, offshore sightseeing or breeding platforms, Antarctica, and frontiers with abundant wind resources, further improving the survivability of the wind turbine mechanical structure and electrical system.

[0020] These and other aspects of the invention will be more clearly elucidated with reference to the embodiments described hereinafter. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The structure and further objects and advantages of the present invention will be better understood from the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements: Figure 1 is a partial three-dimensional schematic diagram of a small wind turbine according to a specific embodiment of the present invention; Figure 2 is a partial three-dimensional schematic diagram of the small wind turbine according to this specific embodiment of the present invention from another angle; Figure 3 yes Figure 1 A schematic cross-sectional view of one of the blade assemblies of the small wind turbine shown in the figure, cut longitudinally through its variable centrifugal flybar assembly; Figure 4 yes Figure 1 A three-dimensional exploded schematic diagram of one of the blade assemblies of the small wind turbine exploded in its variable centrifugal flybar assembly; Figure 5 yes Figure 1 A partial cross-sectional schematic diagram of one of the blade assemblies of the small wind turbine shown in FIG. Figure 6 yes Figure 1 A cross-sectional schematic diagram of a variable flying rod synchronous pitch mechanism (with the guide cover retained) of a small wind turbine is shown. DETAILED DESCRIPTION

[0022] The specific embodiments of the present invention will be described below in conjunction with the accompanying drawings. However, it should be understood that the embodiments disclosed herein are only typical examples of the present invention, which can be embodied in various forms. Therefore, the specific details disclosed herein are not considered to be restrictive, but only as a basis for the claims and as a representative basis for teaching those skilled in the art to apply the present invention differently in any appropriate manner in practice.

[0023] 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 a plurality of blade assemblies 10 and a hub 11, a variable fly rod synchronous pitch mechanism 300 installed on the impeller 100, and a nacelle (not shown) with a built-in generator, 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 plurality of blade assemblies.

[0024] like Figure 3 and Figure 4 As shown, and refer to Figure 1 and Figure 2 In this embodiment, the variable centrifugal fly rod assembly 500 includes a centrifugal fly rod base 51 suitable for being installed on the blade assembly 10 of the wind turbine, a centrifugal fly rod guide sleeve 53 which is adjustably installed in the centrifugal fly rod base 51, a preload adjustment assembly which is adjustably installed in the inner end of the centrifugal fly rod guide sleeve 53, a linear bearing 55 which is fixedly installed in the outer end of the centrifugal fly rod guide sleeve 53, a centrifugal fly rod guide rod 57 which is slidably installed through the linear bearing 55, a centrifugal fly rod spring 58 and a fly rod counterweight sleeve 59, wherein an end platform 570 is provided at the inner end of the centrifugal fly rod guide rod 57, and the centrifugal fly rod spring 58 is sleeved on the centrifugal fly rod guide rod 57 and limited in position. Between the end platform 570 and the linear bearing 55, the fly rod counterweight sleeve 59 is sleeved on the outer end of the centrifugal fly rod guide rod 57, and the centrifugal fly rod spring 58 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 57 is pressed against the preload adjustment component under the action force (i.e., restoring force) of the centrifugal fly rod spring 58; when the speed of the wind turbine impeller 100 reaches a predetermined speed, that is, when the centrifugal force of the variable centrifugal fly rod assembly 500 reaches a certain level, the centrifugal fly rod guide rod 57 moves outward with the fly rod counterweight sleeve 59, thereby further compressing the centrifugal fly rod spring 58 to make it enter a re-compression state. It should be noted that the predetermined speed is greater than the rated speed of the wind turbine.

[0025] Preferably, if Figure 3As shown, in the present 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 at 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.

[0026] like Figure 3 and Figure 4 As 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 passes through the pre-tightening adjustment nut 52 and is threadedly matched 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.

[0027] like Figures 1 to 5 As shown, in this embodiment, each blade assembly 10 includes a petiole shaft 12 fixedly mounted on the hub 11, a petiole flange 14 rotatably mounted on the petiole shaft 12, and a blade 16 fixedly mounted on the petiole flange 14, wherein the centrifugal fly rod base 51 of the variable centrifugal fly rod assembly 500 is fixedly mounted on the petiole flange 14.

[0028] For example Figure 5 As shown, each blade assembly 10 also includes a bearing A13, a bearing B15 and a fastener 17, wherein the bearing A13 and the bearing B15 are fixedly mounted on the petiole flange 14 at their outer rings and fixed on the petiole shaft 12 at their inner rings, and the fastener 17 is threadedly mounted on the outer end of the petiole shaft 12 and abuts against the outer end surface of the inner ring of the bearing B15. In this embodiment, the bearing A13 and the bearing B15 are both tapered bearings and are arranged back to back. Specifically, the bearing A13 and the bearing B15 are respectively mounted on the bearing holes at both ends of the petiole flange 14, and the petiole shaft 12 passes through the bearing A13 and the bearing B15 and is fixed to their inner rings.

[0029] like Figure 6 As shown, and refer to Figure 1 and Figure 2 In 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 arranged 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 preload nut 36 is threadedly installed on the guide shaft 32 and presses inwardly 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 petiole flange 14.

[0030] like Figure 6 As shown, in the present embodiment, a guide key (not shown) is provided on the synchronization disk 31, and correspondingly, a guide key slot (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 slot, thereby compressing or releasing the pitch spring 34.

[0031] 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 shank flange 14 via a pin (not shown).

[0032] For example Figure 6 As shown, in this embodiment, the variable flying rod synchronous pitch mechanism 300 further includes a guide cover 35, and the guide cover 35 is threadedly installed 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 guide cover 35 is schematically 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.

[0033] In addition, if Figure 2As clearly shown, in the present 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.

[0034] The present invention is further described below from two aspects: mechanism motion and mechanism mechanism.

[0035] Description of Institutional Movement: 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 in the direction perpendicular to the paper); 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 in 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 petiole flange 14, so that the petiole flange 14 rotates around the petiole axis 12. The petiole 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, and at the same time compresses 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, i.e., the predetermined rotational speed, the pitch spring 34 is further compressed, and the blades 16 pitch. During the pitch changing 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 pitch changing trend of the blades 16. At the same time, when the blades 16 pitch to a certain value, i.e., the pitch spring 34 is compressed to a certain degree, 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.

[0036] The second main line of movement: the variable centrifugal fly rod assembly 500 is installed on the petiole flange 14. In the XZ plane, the variable centrifugal fly rod assembly 500 is arranged at an angle to the petiole 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, and the component of the 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 are in action. Specifically, most of the work generated by the centrifugal force component in the Z axis will be stored in the centrifugal fly rod spring 58, and part of the energy will be decomposed into the linear bearing 55 and the preload adjustment screw 54 to generate friction loss. 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). , preload adjustment screw 54, preload adjustment nut 52, centrifugal fly rod spring 58 and linear bearing 55 are all fixed parts, and the components generated in the Z axis of these parts are ultimately absorbed by the petiole flange 14, petiole shaft 12 and hub 11), and the other part becomes friction loss due to the existence of movable parts (the centrifugal force of the centrifugal fly rod guide rod 57 and the fly rod counterweight sleeve 59 inside the variable centrifugal fly rod assembly 500 generates components in the Z axis that are decomposed into radial components of the centrifugal fly rod guide rod 57, which react with the linear bearing 55 to generate friction resistance, and the centrifugal force of these movable parts generates components in the Z axis that are decomposed into axial components of the centrifugal fly rod guide rod 57, which will overcome the friction resistance of the linear bearing 55 and compress the pre-stressed centrifugal fly rod spring 58, wherein the axial components of the centrifugal fly rod guide rod 57 generated by the Z axis are balanced with the elastic force from the centrifugal fly rod spring 58 and the friction force from the linear bearing 55).

[0037] Mechanism description: 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 rotation speed, and r is the distance from the center of mass to the axis of rotation; 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. From the centrifugal force calculation formula, it can be seen that once the product structure, i.e. the centrifugal fly bar, is formed, its mass parameter m basically does not change. The final adjustment (or balance) of the centrifugal fly bar is the speed parameter ω, i.e. the ω parameter is our final control target. In the present invention, the variable centrifugal fly rod assembly 500 only changes the center of mass position (corresponding to the parameter r in the centrifugal force calculation formula) to increase the fly rod centrifugal force. Since the center of mass change also has a certain relationship with ω^2, that is, the r parameter can be written as the expression r(ω^2) (the expression r(ω^2) indicates that r has a direct mathematical relationship with the rotation speed ω^2). When the rotation speed increases, r also increases. As r increases, it can be seen from the centrifugal force calculation formula F=mω^2r that the centrifugal force F also increases, and the blade 16 can rotate to achieve variable pitch, so that the rotation speed is reduced, and then the centrifugal force is also reduced, and r is also reduced; The rated speed of the impeller 100 of the wind turbine is set to ω0. After the pitch spring 34 is pre-stressed, the variable centrifugal fly rod assembly 500 needs to be at ω1 to start the variable fly rod synchronous pitch mechanism 300 to compress the pitch spring 34 again. Note that the centrifugal fly rod spring 58 is also in a pre-stressed state at this time, that is, it has not reached the activated state. When the rotation speed of the impeller 100 continues to increase slightly to reach 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 generates a component in the Z axis that 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; 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 generates 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 direction of increase; Under the same speed condition, 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 will increase with the increase of the speed. The center of mass position of the variable centrifugal fly rod assembly 500 conforms to the expression r (ω^2). The calculation formula of the centrifugal force mentioned above is F=m*ω^2*r, then the calculation formula of the centrifugal force 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 relative speed ω parameter than the centrifugal force of the fixed fly rod assembly. Under the same speed condition, 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. 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 synchronous disk 31 to compress the pitch spring 34, which can make the pitch spring 34 more compressed and reach a balance. The blades 16 fixed on the blade stalk flange 14 also obtain more angle adjustment, so that the blades 16 are out of the optimal working condition. 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.

[0038] The technical content and technical features of the present invention have been disclosed above, but it is understood that under the creative ideas of the present invention, those skilled in the art can make various changes and improvements to the above structure, including the combination of technical features disclosed or claimed separately here, and other combinations that obviously include these features. These variations and / or combinations all fall within the technical field involved in the present invention and fall within the protection scope 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 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 component 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 an end platform is arranged at the inner end of the centrifugal fly rod guide rod, 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 arranged to be able to switch between an initial compression state and a re-compression state, and 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 rotation speed of the wind turbine impeller reaches a predetermined rotation speed, the centrifugal fly rod guide rod moves outward with the fly rod counterweight sleeve, thereby further compressing the centrifugal fly rod spring to make it enter a re-compression 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, 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 rotation speed is greater than the rated rotation speed of the wind turbine.

4. A small wind turbine, comprising an impeller having a hub and a plurality of blade assemblies, a variable flying rod 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 a 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 blade assembly includes a petiole shaft fixedly mounted on the hub, a petiole flange rotatably mounted on the petiole shaft, and a blade fixedly mounted on the petiole flange, wherein the centrifugal fly rod base of the variable centrifugal fly rod assembly is fixedly mounted on the petiole flange.

6. The small wind turbine according to claim 5, characterized in that: Each of the blade assemblies also 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 face 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 arranged back to back with a spaced relationship.

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 ball bearings installed on both ends of each pull rod, wherein the guide shaft is coaxially fixed to the 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 inwardly 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 petiole flange.

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

Images