Active variable pitch mechanism for small fan and small fan comprising same

Abstract

The utility model relates to an active variable pitch mechanism for a small fan and the small fan comprising the active variable pitch mechanism, which comprise a synchronous pull rod guide seat, a synchronous moving unit comprising a synchronous pull rod guide shaft, a synchronous pull rod and a three-jaw synchronous disc with three jaw parts, and three variable pitch units, the synchronous pull rod guide shaft is mounted in the synchronous pull rod guide seat in a manner of axially moving for a certain distance, the synchronous pull rod is fixedly connected to the inner end of the synchronous pull rod guide shaft, and the three-jaw synchronous disc is fixedly connected to the outer end of the synchronous pull rod guide shaft; the variable-pitch unit comprises a self-lubricating sliding block, a blade handle crankshaft and a variable-pitch bearing with a rotatable inner ring and a fixed outer ring, the self-lubricating sliding block is in sliding connection with the claw part and is rotatably connected with the inner end of the blade handle crankshaft, the outer end of the blade handle crankshaft is fixedly connected to the inner end face of the rotatable inner ring of the variable-pitch bearing, and the variable-pitch bearing is fixed to the hub through the fixed outer ring; the outer end face of the rotatable inner ring of the variable pitch bearing is connected with the blades. The utility model has the advantages of small volume, compact structure, reduced load and long service life and maintenance period.

Description

Technical Field

[0001] The utility model relates to the technical field of wind power generators, and in particular to an active variable pitch mechanism for a small wind turbine and a small wind turbine comprising the active variable pitch mechanism. Background Art

[0002] The output power of a wind turbine is directly related to the energy absorbed by the wind wheel (i.e. impeller). When the rated wind speed is exceeded, the wind turbine must use various means to limit the wind wheel speed or limit the power absorbed by the wind wheel to ensure normal and stable operation of the wind turbine before the wind speed is cut out.

[0003] At present, there are many measures to reduce the speed of the wind rotor. Large wind turbines have sufficient impeller space. The most common method is to use synchronous control of multiple reduction motors to implement three-blade simultaneous pitch control. Small wind turbines have methods such as tail folding, centrifugal pitch control, flexible blades with similar pitch control effects, or generator electromagnetic torque to limit the speed of the wind rotor. However, in the existing technology, these measures for small wind turbines have their own problems:

[0004] The tail-folding power limiting measures for small wind turbines are relatively common. The blades are lateral to the wind blade handle and the alternating load stress conditions of the generator shaft are aggravated. In extreme wind speed conditions, the impeller still absorbs a lot of power. The wind rotor speed and output power cannot be completely limited to a safe range. Accidents of fatigue damage to the blade structure and the generator shaft occur from time to time. Such small wind turbines are suitable for areas with low annual average wind speeds.

[0005] Some small wind turbines use centrifugal pitch control technology, which also has limitations. Because spring energy is used, friction work causes a certain lag in pitch response. In places with severe turbulent wind speeds, overvoltage and other phenomena may occur. Moreover, the larger the wind rotor, the more prominent the lag in the mechanism response.

[0006] Flexible blade structures were only used by a wind turbine company in Spain a few years ago, but they are expensive, and the special material treatment at the root of the blades requires good elastic memory. It is also difficult to accurately control the elastic force of the impeller in manufacturing, especially the synchronization of the three blades. Mass production and large-scale promotion may have major risks.

[0007] The electromagnetic torque of the generator drags the wind wheel, limiting the increase in the speed of the wind wheel and further achieving the purpose of controlling the energy absorption of the wind wheel. However, to achieve this goal, a larger capacity generator is needed. In the current cycle of crazy price increases of rare earth magnets and copper raw materials, the electricity sales price is still approaching that of thermal power, which means that the return on investment is further reduced. Utility Model Content

[0008] In order to overcome the above-mentioned deficiencies in the measures for limiting the impeller rotation speed of a small fan, the utility model will advantageously provide an active variable pitch mechanism for a small fan and a small fan including the same.

[0009] To this end, according to one aspect of the utility model, an active pitch mechanism for a small wind turbine is provided, comprising:

[0010] A synchronous pull rod guide seat is coaxially fixed on the inner end of the hub of the small fan;

[0011] A synchronous moving unit, comprising a synchronous pull rod guide shaft, a synchronous pull rod and a three-claw synchronous disc having three claws, wherein the synchronous pull rod guide shaft can be installed in a synchronous pull rod guide seat so as to be axially movable for a certain distance, the synchronous pull rod is fixedly connected to the inner end of the synchronous pull rod guide shaft, and the three-claw synchronous disc is fixedly connected to the outer end of the synchronous pull rod guide shaft;

[0012] There are three pitch units, each of which includes a self-lubricating slider, a blade crankshaft, and a pitch bearing with a rotatable inner ring and a fixed outer ring. The self-lubricating slider is slidingly connected to the corresponding claw portion on the three-claw synchronization disk on the outside and rotatably connected to the inner end of the blade crankshaft on the inside. The outer end of the blade crankshaft is fixedly connected to the inner end face of the rotatable inner ring of the pitch bearing. The pitch bearing is fixed to the hub via its fixed outer ring, and the outer end face of the rotatable inner ring of the pitch bearing is connected to the blade.

[0013] Furthermore, the self-lubricating slider is a copper-based graphite self-lubricating slider. The claw of the three-claw synchronous disk has a U-shaped groove milled at its end. The self-lubricating slider can be slidably installed in the U-shaped groove, and when the synchronous pull rod guide shaft moves axially for a certain distance in the synchronous pull rod guide seat, the self-lubricating slider is always in the U-shaped groove.

[0014] Furthermore, a long keyway is provided on the synchronous pull rod guide seat, and a guide key is installed on the synchronous pull rod guide shaft. Through the cooperation of the guide key and the long keyway, the synchronous pull rod guide shaft can axially move a certain distance relative to the synchronous pull rod guide seat.

[0015] Furthermore, the self-lubricating slider is provided with a cylindrical inner hole and an annular positioning hole connected to the cylindrical inner hole. The self-lubricating slider cooperates with the inner end cylinder of the petiole crankshaft via the cylindrical inner hole, and the self-lubricating slider is axially limited relative to the petiole crankshaft via the annular positioning hole and the positioning bolt.

[0016] Furthermore, the synchronous pull rod is threadedly connected to the synchronous pull rod guide shaft, and the synchronous pull rod is further fastened to the synchronous pull rod guide shaft by adjusting the locking nut.

[0017] Furthermore, the three-claw synchronous disc and the synchronous pull rod guide shaft are fixed together by pins.

[0018] Furthermore, the outer end surface of the rotatable inner ring of the pitch bearing is connected to the blade transition flange of the blade.

[0019] According to another aspect of the utility model, a small wind turbine is provided, which includes the above-mentioned active variable pitch mechanism for the small wind turbine.

[0020] Furthermore, the small wind turbine also includes an impeller cover, and the impeller cover, the hub, the synchronous pull rod guide seat, the pitch bearing, and the blades form a closed space, and the active pitch mechanism for the small wind turbine is located in the closed space.

[0021] Compared with the prior art, the utility model has the following advantages:

[0022] 1) Compared with the existing centrifugal variable pitch mechanism, whose impeller part adopts a more conventional connecting rod structure, the crank slider principle mechanism adopted in the utility model can greatly reduce the volume of the entire mechanism, and can well place the mechanism inside the hub cavity, thus ensuring that the mechanism is not affected by the complex external environment, and the operation is more stable and durable during the life cycle of the product;

[0023] 2) The compact impeller structure can make the impeller's rotational inertia smaller, and the response speed to wind speed energy absorption will also be improved. That is, under the same wind field conditions, the annual power generation of the wind turbine at the same installation location and the same installation height will be increased. For the wind turbine braking protection, the brake workload can also be reduced. In addition, the structural parts are designed to be lightweight to ensure that the overall weight of the impeller is light and reduce the external load of the whole machine;

[0024] 3) The utility model has a relatively simple structural mechanism, a simple structure, a small number of parts, and simple processing of shaft parts. Most of the parts can be cast to reduce the amount of processing and welding and adapt to mass production. The assembly difficulty is not high, no special tooling is required, and the production cost can be greatly reduced;

[0025] 4) Since the copper-based graphite self-lubricating slider adopts self-lubricating composite materials, 2# extreme pressure lithium-based grease (i.e. grease) will be applied to the friction pair of the crank slider mechanism before the impeller is packaged. After the impeller is packaged, only the blades need to be installed on the project site. The lubrication maintenance inside the impeller only needs to be maintained once a long time (for example, once every 3 years), and the impeller cover at the front of the impeller can be opened for maintenance. Moreover, even if the grease has been consumed before maintenance, the copper-based graphite composite material of the copper-based graphite self-lubricating slider has its own self-lubricating effect, which can ensure that the copper-based graphite self-lubricating slider will slide back and forth along the groove of the U-shaped groove of the three-claw synchronous disk, and the relative rotational movement between the copper-based graphite self-lubricating slider and the blade crankshaft will not get stuck.

[0026] These and other aspects of the present invention will be more clearly explained by referring to the embodiments described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] 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 the same reference numerals identify the same elements:

[0028] Figure 1 It is a three-dimensional structural schematic diagram of a small-sized wind turbine including an active variable pitch mechanism for a small-sized wind turbine according to a specific embodiment of the utility model, and only the impeller part of the small-sized wind turbine is shown for the sake of clarity;

[0029] Figure 2 yes Figure 1 The schematic diagram of the cross-sectional structure of the small wind turbine shown is cut along the axis of the synchronous pull rod of the active pitch mechanism of the small wind turbine;

[0030] Figure 3 yes Figure 1 The cross-sectional structure diagram of the small wind turbine shown is a diagram of a cross-sectional structure of the small wind turbine cut along the U-shaped notch on the synchronous disk of the active pitch mechanism of the small wind turbine toward the center. DETAILED DESCRIPTION

[0031] 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.

[0032] In this document, directional expressions such as "inside", "outside", etc., used to explain the structure and / or movement of the various parts of the disclosed embodiments are not absolute, but relative. These expressions are appropriate when the various parts of the disclosed embodiments are located in the positions shown in the figures, and if the position or reference system of the disclosed embodiments changes, these expressions should also change according to the change of the position or reference system of the disclosed embodiments.

[0033] like Figures 1 to 3As shown, according to one aspect of the utility model, an active variable pitch mechanism for a small wind turbine comprises a synchronous rod guide seat 2 coaxially fixed to the inner end 11 of the hub 1 of the small wind turbine along the central axis direction of the impeller 100 (not shown in the figure), a synchronous moving unit and three variable pitch units, wherein the synchronous moving unit comprises a synchronous rod guide shaft 3, a synchronous rod 4 and a three-claw synchronous disk 5 having three claws 50, the synchronous rod guide shaft 3 can be axially moved for a distance and is installed in the synchronous rod guide seat 2, the synchronous rod 4 is fixedly connected to the inner end of the synchronous rod guide shaft 3, and the three-claw synchronous disk 5 is fixedly connected to On the outer end of the synchronous pull rod guide shaft 3; each variable pitch unit includes a self-lubricating slider 6, a petiole crankshaft 7, a variable pitch bearing 8 with a rotatable inner ring 81 and a fixed outer ring 83, the self-lubricating slider 6 is slidingly connected to the corresponding claw portion 50 on the three-claw synchronous disk 5 on the outside, and is rotatably connected to the inner end 70 of the petiole crankshaft 7 on the inside, the outer end 72 of the petiole crankshaft 7 is fixedly connected to the inner end face 810 of the rotatable inner ring 81 of the variable pitch bearing 8, the variable pitch bearing 8 is fixed to the hub 1 via its fixed outer ring 83, and the outer end face 812 of the rotatable inner ring 81 of the variable pitch bearing 8 is connected to the blade 105.

[0034] like Figure 2 As shown, in this embodiment, a long keyway (not shown) is provided on the synchronous tie rod guide seat 2, and a guide key 30 is installed on the synchronous tie rod guide shaft 3. Through the cooperation of the guide key 30 and the long keyway, the synchronous tie rod guide shaft 3 can be axially moved a certain distance relative to the synchronous tie rod guide seat 2. Through the key cooperation between the synchronous tie rod guide shaft 3 and the synchronous tie rod guide seat 2, the synchronous tie rod guide shaft 3 is free in the axial direction relative to the wheel hub 1. It should be understood that the distance of the axial movement of the synchronous tie rod guide shaft 3 is determined by the length of the long keyway, and of course, it is also determined according to the pitch range of the blade 105.

[0035] For example Figure 2 As shown, in this embodiment, the synchronous pull rod 4 is threadedly connected to the synchronous pull rod guide shaft 3, and the synchronous pull rod 4 is further fastened to the synchronous pull rod guide shaft 3 by adjusting the locking nut 94. Through the threaded connection structure of the synchronous pull rod 4 and the synchronous pull rod guide shaft 3, the assembly length can be appropriately adjusted to adapt to the assembly error caused by mass production; adjusting the installation of the locking nut 94 can be used to prevent the synchronous pull rod 4 from loosening relative to the synchronous pull rod guide shaft 3.

[0036] In addition, if Figure 2As shown, in this embodiment, the three-claw synchronous disc 5 and the synchronous pull rod guide shaft 3 are fixed together by a pin 95, so that the three-claw synchronous disc 5 can move axially relative to the wheel hub 1. In this embodiment, the three-claw synchronous disc 5 is not limited to a thick plate and bar welding machine structure, but can also adopt a ductile iron structure that saves processing and welding workload; the wheel hub 1 is not limited to a welded structure, but can also adopt a more compact casting structure.

[0037] like Figure 2 and Figure 3 As shown, in this embodiment, the outer end surface 812 of the rotatable inner ring 81 of the pitch bearing 8 is connected to the blade transition flange 115 of the blade 105 .

[0038] For example Figure 2 and Figure 3 As shown, in the present embodiment, the self-lubricating slider 6 is a copper-based graphite self-lubricating slider, and the claw portion 50 of the three-claw synchronous disk 5 has a U-shaped groove 56 milled at its end. The self-lubricating slider 6 can be slidably installed in the U-shaped groove 56, and when the synchronous pull rod guide shaft 3 moves axially for a certain distance in the synchronous pull rod guide seat 2, the self-lubricating slider 6 is always in the U-shaped groove 56.

[0039] like Figure 3 As shown clearly, in this embodiment, the self-lubricating slider 6 is provided with a cylindrical inner hole 60 and an annular positioning hole 62 connected to the cylindrical inner hole 60. The self-lubricating slider 6 is cylindrically matched with the inner end 70 of the blade crankshaft 7 via the cylindrical inner hole 60, and the self-lubricating slider 6 is axially limited relative to the blade crankshaft 7 via the annular positioning hole 62 and the positioning bolt (not shown). Through this structural setting, the self-lubricating slider 6 can rotate freely around the blade crankshaft 7, but is axially limited relative to the blade crankshaft 7. In this embodiment, the blade crankshaft 7 is not limited to a thick plate and bar welding machine structure, and can also adopt a casting structure that saves processing and welding workload.

[0040] It should be noted that the three-claw synchronous disc 5 moves along the central axis direction of the impeller 100 (i.e., the direction of the axis centerline of the synchronous rod guide shaft 3) relative to the hub 1 and the synchronous rod guide seat 2. When the U-shaped notch 56 of the three-claw synchronous disc 5 moves along the central axis of the impeller in the hub 1, it will drive the self-lubricating slider 6 to move together. Specifically, the three-claw synchronous disc 5 drives the three self-lubricating sliders 6 to move axially along the synchronous rod guide shaft 3 through three circumferentially evenly divided U-shaped notches 56. At the same time, the self-lubricating sliders 6 will also slide back and forth along the groove direction of the U-shaped notch 56. The cylindrical inner hole 60 of the self-lubricating slider 6 and the blade crankshaft 7 will have relative rotational movement. The synthetic movement of the above three movements of the self-lubricating slider 6 causes the blade crankshaft 7 to drive the rotatable inner ring 81 of the variable pitch bearing 8 to rotate around the axis centerline of the fixed outer ring 83. In this process, the angle rotation movement of the blade 105 is realized through the push-pull action of the synchronous rod 4, that is, the variable pitch result of the blade 105 is realized. That is to say, the push-pull action of the synchronous pull rod 4 can drive the synchronous pull rod guide shaft 3 and the synchronous disk 5 to move axially, so that the self-lubricating slider 6 drives the blade shank crankshaft 7, and then drives the rotatable inner ring 81 of the variable pitch bearing 8 to rotate, and finally drives the blade 105 to rotate to achieve variable pitch. The three-blade synchronous pitch is realized by the three-claw synchronous disk 5, and the weight is lightened at the same time. The linear motion of the three-claw synchronous disk 5 is converted into the rotational motion of the blade shank crankshaft 7 around the axis of the blade 105 through the crank slider mechanism (self-lubricating slider 6 and blade shank crankshaft 7). Such a process is more compact than the connecting rod structure in the prior art.

[0041] like Figure 1 As shown, and refer to Figure 2 and Figure 3 According to another aspect of the utility model, a small wind turbine is provided, which includes the above-mentioned active variable pitch mechanism for a small wind turbine, and the small wind turbine also includes an impeller cover 101, and the impeller cover 101, the hub 1, the synchronous pull rod guide seat 2, the variable pitch bearing 8, and the blade 105 (including the blade transition flange 115 thereon) form a closed space 110, and the active variable pitch mechanism for a small wind turbine is located in the closed space 110, which can effectively protect the parts in the closed space 110 from being affected by the harsh external environment such as wind, sand, salt spray, etc. It should be noted that the blade transition flange 115 can be omitted as needed, and the blade 105 is directly mounted on the rotatable inner ring 81 of the variable pitch bearing 8.

[0042] The active variable pitch wind turbine of the utility model has controllable cost, reasonable structure and lightweight impeller, which can not only assist in starting the impeller at low wind speed, but also ensure safe and stable power output before cutting out the wind speed in high winds. At the same time, it can also ensure that the blades are aligned after cutting out the wind speed, thereby reducing the impeller load to the greatest extent, ensuring the ability to survive extreme climate conditions such as typhoons, obtaining maximum operating time and operating stability, reducing the load impact of subsequent electronic control devices, obtaining more power output, and further enhancing the value of the small wind turbine.

[0043] The technical content and technical features of the utility model have been disclosed above, but it can be understood that under the creative idea of ​​the utility model, 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 deformations and / or combinations all fall within the technical field involved in the utility model and fall within the protection scope of the claims of the utility model.

Claims

1. An active pitch mechanism for a small wind turbine, characterized in that include: A synchronous pull rod guide seat is coaxially fixed on the inner end of the hub of the small fan; A synchronous moving unit, comprising a synchronous pull rod guide shaft, a synchronous pull rod and a three-claw synchronous disc having three claws, wherein the synchronous pull rod guide shaft can be installed in a synchronous pull rod guide seat so as to be axially movable for a certain distance, the synchronous pull rod is fixedly connected to the inner end of the synchronous pull rod guide shaft, and the three-claw synchronous disc is fixedly connected to the outer end of the synchronous pull rod guide shaft; There are three pitch units, each of which includes a self-lubricating slider, a blade crankshaft, and a pitch bearing with a rotatable inner ring and a fixed outer ring. The self-lubricating slider is slidingly connected to the corresponding claw portion on the three-claw synchronization disk on the outside and rotatably connected to the inner end of the blade crankshaft on the inside. The outer end of the blade crankshaft is fixedly connected to the inner end face of the rotatable inner ring of the pitch bearing. The pitch bearing is fixed to the hub via its fixed outer ring, and the outer end face of the rotatable inner ring of the pitch bearing is connected to the blade.

2. The active pitch mechanism for a small wind turbine according to claim 1, characterized in that: The self-lubricating slider is a copper-based graphite self-lubricating slider. The claw portion of the three-claw synchronous disk has a U-shaped groove milled at its end. The self-lubricating slider can be slidably installed in the U-shaped groove, and when the synchronous pull rod guide shaft moves axially for a certain distance in the synchronous pull rod guide seat, the self-lubricating slider is always in the U-shaped groove.

3. The active pitch mechanism for a small wind turbine according to claim 2, characterized in that: The synchronous pull rod guide seat is provided with a long keyway, and the synchronous pull rod guide shaft is equipped with a guide key. Through the cooperation of the guide key and the long keyway, the synchronous pull rod guide shaft can axially move a certain distance relative to the synchronous pull rod guide seat.

4. The active pitch mechanism for a small wind turbine according to claim 3, characterized in that: The self-lubricating slider is provided with a cylindrical inner hole and an annular positioning hole connected to the cylindrical inner hole. The self-lubricating slider cooperates with the inner end cylinder of the petiole crankshaft via the cylindrical inner hole, and the self-lubricating slider is axially limited relative to the petiole crankshaft via the annular positioning hole and the positioning bolt.

5. The active pitch mechanism for a small wind turbine according to claim 4, characterized in that: The synchronous pull rod is threadedly connected to the synchronous pull rod guide shaft, and the synchronous pull rod is further fastened to the synchronous pull rod guide shaft by adjusting the locking nut.

6. The active pitch mechanism for a small wind turbine according to claim 5, characterized in that: The three-claw synchronous disc and the synchronous pull rod guide shaft are fixed together by pins.

7. The active pitch mechanism for a small wind turbine according to any one of claims 1 to 6, characterized in that: The outer end surface of the rotatable inner ring of the pitch bearing is connected to the blade transition flange of the blade.

8. A small wind turbine, comprising the active variable pitch mechanism for a small wind turbine as claimed in any one of claims 1 to 7.

9. The small fan according to claim 8, characterized in that It also includes an impeller cover, which forms a closed space with the wheel hub, the synchronous pull rod guide seat, the pitch bearing and the blades. The active pitch mechanism for the small wind turbine is located in the closed space.

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