Passive variable pitch mechanism for small fan and small fan comprising passive variable pitch mechanism

Abstract

The utility model relates to a passive variable pitch mechanism for a small fan, which comprises a support guide shaft coaxially fixed on a hub of the small fan and provided with an annular shoulder; the synchronous moving unit comprises a synchronous disc and a spring, the synchronous disc is axially and movably arranged on the supporting guide shaft in a sleeving manner, and the spring is arranged on the supporting guide shaft in a sleeving manner between the annular shoulder and the synchronous disc; each variable pitch unit comprises a centrifugal flying rod, an adjustable pull rod and a crank, the centrifugal flying rod is arranged on a blade handle of a corresponding blade of the small fan, joint bearings are arranged at the two ends of the adjustable pull rod, one joint bearing is rotatably connected with a synchronous disc through a first pull rod pin shaft, and the other joint bearing is rotatably connected with a second pull rod pin shaft; and the other knuckle bearing is rotatably connected with one end of a crank through a second pull rod pin shaft, and the other end of the crank is fixedly connected to a blade handle shaft of the blade handle. The utility model has the advantages of simple, compact and reliable structure, simple, convenient and effective installation, and light weight design of the whole machine.

Description

Technical Field

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

[0002] In the prior art, small and medium-sized wind turbines will encounter various levels of wind force when operating in the wild. In order to ensure safe operation, small and medium-sized wind turbines are required to adjust the speed according to the wind force to stabilize the power output, while avoiding excessive speed that may damage the entire machine.

[0003] At present, there are several pitch-changing technologies for small and medium-sized wind turbines on the market: active pitch-changing wind turbines, fixed pitch wind turbines, and passive pitch-changing technologies. However, although active pitch-changing wind turbines have a relatively high technical level, their construction and maintenance costs are also very high, and they cannot be promoted in the domestic market at all; although the impeller structure of fixed pitch wind turbines is relatively simple, it requires the addition of other auxiliary structures to limit the power and speed of the wind turbine under strong wind conditions, otherwise the wind turbine with a folded tail will lose part of the energy in strong winds, and the wind turbine's production capacity will decrease. At the same time, it will also cause the impeller to face the wind obliquely, and the uniformity of each blade's working condition is extremely poor, which will inevitably lead to additional instability of the entire machine; and although passive pitch-changing technologies are also available on the market, the existing passive pitch-changing structures are relatively complex and bulky, which is not conducive to light transportation and easy installation, and the existing passive pitch-changing structures are usually exposed to the environment and cannot meet the requirements of applications in extreme environments such as Antarctica. Utility Model Content

[0004] In order to overcome the above problems, the utility model provides a passive pitch mechanism for a small wind turbine that can be used in extreme environments to ensure the safety and stable output of power of the small wind turbine, and a small wind turbine including the same. This will be advantageous.

[0005] To this end, according to one aspect of the utility model, a passive pitch mechanism for a small wind turbine is provided, which comprises:

[0006] A supporting guide shaft is coaxially fixed to the hub of the small fan and is provided with an annular shoulder;

[0007] A synchronous moving unit, comprising a synchronous disc and a spring, wherein the synchronous disc is axially movably sleeved on the supporting guide shaft, and the spring is sleeved on the supporting guide shaft between the annular shoulder and the synchronous disc;

[0008] Multiple variable pitch units, each variable pitch unit includes a centrifugal fly rod, an adjustable pull rod and a crank. The centrifugal fly rod is installed on the petiole of a corresponding blade of the small fan. Both ends of the adjustable pull rod are equipped with joint bearings, one of the joint bearings is rotatably connected to the synchronous disk via a first pull rod pin, and the other joint bearing is rotatably connected to one end of the crank via a second pull rod pin, and the other end of the crank is fixedly connected to the petiole shaft of the petiole.

[0009] Through the above-mentioned structural setting, the passive variable pitch mechanism has a simple structure, is compact and reliable, easy to install, convenient and effective, and at the same time realizes a lightweight design of the entire machine; through the centrifugal variable pitch structure (i.e., the passive variable pitch mechanism), the installation angle of the blade changes as the impeller speed increases, the blade Cp value decreases, and the impeller absorption capacity decreases, thereby achieving the purpose of limiting the speed and power of a small wind turbine.

[0010] Furthermore, an axial long hole is also provided on the support guide shaft, and the synchronous disk is axially movably sleeved on the support guide shaft via a guide bolt installed through the axial long hole so as to be able to move between two extreme positions along the axial long hole.

[0011] Through the above-mentioned structural arrangement, the synchronous disk can move axially and be axially limited relative to the supporting guide shaft.

[0012] Furthermore, the axial long hole is arranged to penetrate the support guide shaft along the diameter direction of the support guide shaft and extend a distance in the axial direction of the support guide shaft.

[0013] Through the above structural arrangement, the synchronizing disk can be moved between two extreme positions along the axial long hole on the supporting guide shaft via the guide bolt.

[0014] Still further, the distance is set according to the blade pitch limit.

[0015] Furthermore, the petiole shaft and the other end of the crank are matched with a square shaft and a square hole.

[0016] Through the above structural cooperation, the other end of the crank is fixed relative to the petiole axis.

[0017] Furthermore, the blade shank shaft is rotatably mounted on the hub via a mounting bearing, so that the torque applied to the blade shank by the centrifugal flying rod is finally applied to the synchronous disk via the blade shank shaft, the crank and the adjustable pull rod.

[0018] Furthermore, the other end of the crank is further fixed to the petiole shaft through a round nut at the inner end of the petiole shaft.

[0019] The above structural arrangement further ensures that the crank is fixed on the petiole shaft.

[0020] According to another aspect of the utility model, a small wind turbine is provided, which includes the above passive pitch mechanism for the small wind turbine.

[0021] Through the use of a passive pitch mechanism, the reliance on frequent use of electronic control systems in small wind turbines, especially those used in extreme environments, can be reduced, so that the electronic control system of small wind turbines can be further simplified, greatly reducing the probability of control system failure in extreme environments, and further ensuring the safety and stability of small wind turbines.

[0022] Furthermore, the above-mentioned small wind turbine also includes a guide cover, which forms a closed space with the hub, the blade shaft, and the mounting bearing that rotatably mounts the blade shaft on the hub, and the passive pitch mechanism for the small wind turbine is located in the closed space.

[0023] By designing the passive pitch mechanism to be housed in a closed space formed by the hub, fairing and blades, the passive pitch mechanism does not need to be exposed to extreme environments, thereby reducing damage to the various components of the mechanism caused by extreme weather (including strong winds, dust, low temperatures, high ultraviolet rays, etc.), thereby improving the service life and equipment safety.

[0024] Furthermore, the fairing is a UV low-temperature resin-based carbon fiber fairing, the wheel hub is an aviation aluminum machined wheel hub, the blades are UV low-temperature resin-based carbon fiber blades, the springs are low-temperature springs, and the petiole shaft is a low-temperature alloy steel petiole shaft.

[0025] Through the above-mentioned structural arrangement, the small-sized fan of the utility model can better meet the requirements of use in special environments such as Antarctica, that is, it is cold-resistant and UV-resistant, and is lightweight, making it easy to install.

[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 schematic diagram of the external structure of a passive variable pitch mechanism for a small wind turbine according to a specific embodiment of the utility model applied to a small wind turbine (the guide cover is removed and the blades are cut off for clarity);

[0029] Figure 2 yes Figure 1 The structure shown is a plan view taken along line AA, showing the deflector;

[0030] Figure 3 yes Figure 2 A three-dimensional schematic diagram of the structure shown;

[0031] Figure 4 yes Figure 1 The structure shown is a partial three-dimensional schematic diagram cut off at the junction of the crank and the petiole axis. DETAILED DESCRIPTION

[0032] 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.

[0033] like Figures 1 to 4 As shown, a passive variable pitch mechanism 1 for a small wind turbine according to a specific embodiment of the utility model comprises a support guide shaft 11, a synchronous moving unit and a plurality of variable pitch units, wherein the support guide shaft 11 is coaxially fixed to a hub 101 of the small wind turbine and is provided with an annular shoulder 110; the synchronous moving unit comprises a synchronous disk 13 and a spring 14, the synchronous disk 13 is axially movably sleeved on the support guide shaft 11, and the spring 14 is sleeved on the support guide shaft 11 between the annular shoulder 110 and the synchronous disk 13; each variable pitch unit The paddle units include a centrifugal fly rod 15, an adjustable pull rod 17 and a crank 19. The centrifugal fly rod 15 is installed on the petiole 115 of a corresponding blade 105 of the small fan. Both ends of the adjustable pull rod 17 are equipped with joint bearings 16. One of the joint bearings 16 is rotatably connected to the synchronous disk 13 via a first pull rod pin 18, and the other joint bearing 16 is rotatably connected to one end 191 of the crank 19 via a second pull rod pin 18. The other end 192 of the crank 19 is fixedly connected to the petiole shaft 125 of the petiole 115.

[0034] like Figure 2 and Figure 3 As shown, in this embodiment, the support guide shaft 11 is further provided with an axial long hole 112, and the synchronization disk 13 is axially movably sleeved on the support guide shaft 11 via a guide bolt 12 installed through the axial long hole 112, so that it can move between two extreme positions along the axial long hole 112. Specifically, the axial long hole 112 is arranged to penetrate the support guide shaft 11 along the diameter direction of the support guide shaft 11, and extend a distance in the axial direction of the support guide shaft 11, and the distance is set according to the pitch limit of the blade 105, that is, the pitch degree range.

[0035] For example Figure 2 and Figure 3As shown, in the present embodiment, the blade stalk shaft 125 and the other end 192 of the crank 19 are square shaft and square hole matched; the other end 192 of the crank 19 is further fixed and limited on the blade stalk shaft 125 by a round nut 145 at the inner end of the blade stalk shaft 125; the blade stalk shaft 125 is rotatably mounted on the hub 101 via the mounting bearing 135, so that the torque applied by the centrifugal fly rod 15 to the blade stalk 115 is finally applied to the synchronous disk 13 via the blade stalk shaft 125, the crank 19 and the adjustable pull rod 17.

[0036] For example Figure 1 and Figure 2 As shown, and refer to Figure 3 and Figure 4 According to another aspect of the utility model, a small wind turbine is provided, which includes the passive variable pitch mechanism 1 for a small wind turbine as described above. In this embodiment, the small wind turbine also includes a guide cover 103, and the guide cover 103, the hub 101, the blade shaft 125, and the mounting bearing 135 that rotatably mounts the blade shaft 125 on the hub 101 form a closed space 113, and the passive variable pitch mechanism 1 for a small wind turbine is located in the closed space 113. In addition, in this embodiment, the guide cover 103 is a UV low-temperature resin-based carbon fiber guide cover, the hub 101 is an aviation aluminum machine-added hub, the blade 105 is a UV low-temperature resin-based carbon fiber blade, the spring 14 is a low-temperature spring, the round nut 145 is a low-temperature alloy steel round nut, and the blade shaft 125 is a low-temperature alloy steel blade shaft. These low-temperature and lightweight designs greatly meet the requirements of cold resistance, UV resistance and easy installation of small wind turbines in special use environments.

[0037] It should be noted that in this embodiment, when the centrifugal fly rod 15 acts on the petiole 115 under the influence of the increased speed of the impeller 100 of the small fan, the torque will gradually increase, and the torque will eventually be transmitted to the crank 19, thereby transmitting the motion to the synchronous disk 13 via the adjustable pull rod 17, thereby realizing the synchronous pitch action of the three blades 105.

[0038] It should be understood that the synchronous disk 13 can only make reciprocating linear motion along the guide shaft 11, and the rear end surface of the synchronous disk 13 acts with the spring 14 to store elastic potential energy. Specifically, as the speed of the centrifugal fly rod 15 continues to increase, the torque becomes larger and larger, which will cause the blade 105 to change pitch at a larger angle, causing the Cp (wind energy utilization coefficient) of the impeller 100 to drop rapidly as the speed increases, and the energy absorbed by the impeller 100 also drops accordingly. As the petiole 115 twists more, the adjustable pull rod 17 will drive the synchronous disk 13 to compress the spring 14 more, thereby causing the spring 14 to store more elastic potential energy, that is, the spring 14 has a greater elastic force, and the elastic force and the force of the centrifugal fly rod 15 on the spring 14 through the synchronous disk 13 reach an adaptive balance under the action of the impeller speed.

[0039] 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. A passive pitch mechanism for a small wind turbine, characterized in that include: A supporting guide shaft is coaxially fixed to the hub of the small fan and is provided with an annular shoulder; A synchronous moving unit, comprising a synchronous disc and a spring, wherein the synchronous disc is axially movably sleeved on the supporting guide shaft, and the spring is sleeved on the supporting guide shaft between the annular shoulder and the synchronous disc; Multiple variable pitch units, each variable pitch unit includes a centrifugal fly rod, an adjustable pull rod and a crank. The centrifugal fly rod is installed on the petiole of a corresponding blade of the small fan. Both ends of the adjustable pull rod are equipped with joint bearings, one of the joint bearings is rotatably connected to the synchronous disk via a first pull rod pin, and the other joint bearing is rotatably connected to one end of the crank via a second pull rod pin, and the other end of the crank is fixedly connected to the petiole shaft of the petiole.

2. The passive pitch mechanism for a small wind turbine according to claim 1, characterized in that: The support guide shaft is also provided with an axial long hole, and the synchronization disk is axially movably sleeved on the support guide shaft via a guide bolt installed through the axial long hole so as to be able to move between two extreme positions along the axial long hole.

3. The passive pitch mechanism for a small wind turbine according to claim 2, characterized in that: The axial long hole is arranged to penetrate the support guide shaft along the diameter direction of the support guide shaft and extend a distance in the axial direction of the support guide shaft.

4. The passive pitch mechanism for a small wind turbine according to claim 3, characterized in that: The distance is set according to the blade pitch limit.

5. The passive pitch mechanism for a small wind turbine according to claim 1, characterized in that: The petiole shaft and the other end of the crank are matched with each other in the form of a square shaft and a square hole.

6. The passive pitch mechanism for a small wind turbine according to any one of claims 1 to 5, characterized in that: The blade shank shaft is rotatably mounted on the hub via a mounting bearing, so that the torque applied to the blade shank by the centrifugal flying rod is finally applied to the synchronous disk via the blade shank shaft, the crank and the adjustable pull rod.

7. The passive pitch mechanism for a small wind turbine according to claim 6, characterized in that: The other end of the crank is further fixed to the petiole shaft through a round nut at the inner end of the petiole shaft.

8. A small wind turbine, comprising the passive pitch mechanism for a small wind turbine according to any one of claims 1 to 7.

9. The small fan according to claim 8, characterized in that It also includes a guide cover, which forms a closed space with the hub, the blade shaft, and a mounting bearing that rotatably mounts the blade shaft on the hub. The passive variable pitch mechanism for the small fan is located in the closed space.

10. The small fan according to claim 9, characterized in that: The deflector is a UV low-temperature resin-based carbon fiber deflector, the wheel hub is an aviation aluminum machined wheel hub, the blades are UV low-temperature resin-based carbon fiber blades, the spring is a low-temperature spring, and the petiole shaft is a low-temperature alloy steel petiole shaft.

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