Rotating shaft of vertical-axis wind turbine and using method of rotating shaft

Abstract

The invention relates to the field of wind driven generators, and discloses a vertical axis wind driven generator rotating shaft and a using method thereof.The vertical axis wind driven generator rotating shaft comprises a plurality of shaft units, the shaft units are sequentially and axially connected into a whole to form the rotating shaft, each shaft unit comprises a shaft pipe, the two ends of each shaft pipe are connected with flange plates through connectors, and each shaft unit is divided into a long shaft and a short shaft; the length of a shaft tube of the long shaft is more than 10 times that of the short shaft, the long shaft and the short shaft are alternately connected to form a rotating shaft, the shaft tube of the long shaft is made of carbon fiber materials, and the connector, the flange plate and the shaft tube of the short shaft are all made of metal materials. The rotating shaft of the vertical-axis wind turbine is used as a central shaft of the vertical-axis wind turbine for supporting wind turbine blades. The problems that a rotating shaft of a large vertical axis wind generating set is made of steel and is large in weight and unstable can be solved.

Description

Technical Field

[0001] The invention relates to the field of wind turbines, and in particular to a rotating shaft of a vertical-axis wind turbine and a use method thereof. Background Art

[0002] Wind energy is a clean, renewable form of energy that can be used to drive generators to generate electricity. Currently, the energy generated by wind power generation only accounts for a small part, because ordinary wind turbines are not only heavy and difficult to install, but also expensive and noisy, making it difficult to achieve widespread application. However, as the demand for energy increases, the use of wind energy cannot be ignored.

[0003] According to the different designs of wind turbines, wind power generation can be divided into two categories: horizontal axis wind turbines (HAWTs) and vertical axis wind turbines (VAWTs). Horizontal axis wind turbines need to build a base as high as tens of meters to capture wind energy in higher spaces, and then install a chassis and a horizontal main shaft on the top of the base. The horizontal main shaft is used to support multiple vertically rotating wind blades. It occupies a large area, has a large volume, a large weight, and is difficult to adjust the wind capture direction, which has great application limitations. Vertical axis wind turbines use multiple blades rotating around a vertical axis, which occupies less lateral space, has a relatively smaller blade size, and can capture wind energy in any wind direction without repositioning. Therefore, the tower height can usually be set lower, so that the wind blades can capture wind energy near the ground. However, it is also difficult to capture and utilize high-altitude wind energy. If it can have both the capture and utilization efficiency of high-altitude wind energy by horizontal axis wind power generation and the omnidirectionality of vertical axis wind power generation, the capture and utilization effect of wind energy can be greatly improved.

[0004] If the wind energy in a higher space is to be captured and utilized by vertical axis wind power generation, the rotating shaft in the transmission system of the vertical axis wind turbine generator set is an extremely important component. Its main function is to support the central axis of the wind rotor blades and transmit the rotation and energy of the blades to the speed change system and the generator system. The wind speed in a higher space is relatively high and the wind energy is sufficient. Now it is planned to design a large vertical axis wind turbine generator set with a height of 62 meters. Because of the high height, it is planned to adopt a two-group design, and the length of each rotating shaft is 31 meters. Because the blade speed is high, the length of the blade group is long (the total length of each group is about 31 meters), and the torque is large (more than 15000N.m), therefore, this rotating shaft has high mechanical performance requirements. At the same time, in order to reduce the resonance of the entire transmission system and increase stability, the diameter requirement is also relatively large (more than Φ140). According to the existing conventional wind power generation technology, the rotating shaft is made of steel, but for this new large vertical axis wind turbine generator set, if the rotating shaft is made of steel, it is bound to increase the weight of the entire transmission shaft system, increase wind resistance, increase energy loss, and reduce wind energy conversion rate. In order to reduce the number of connection parts according to conventional technology, a larger size is usually used, such as using 3 rotating shafts in each group, each section is about 10 meters long. Such steel pipes are difficult to manufacture and transport, and the cost is high. In addition, due to the high height and high center of gravity of this wind power system, the use of steel will also increase the instability of the entire system. At the same time, due to the heavy weight of the shaft, the bearing capacity of the entire transmission system, speed change system, support system, base and other structural parts will also increase, and the manufacturing cost will also increase accordingly. In this case, how to ensure the mechanical properties of the rotating shaft while effectively controlling the weight of the transmission system and ensuring the stability of the entire system is a difficult problem that needs to be solved urgently. Summary of the invention

[0005] The present invention is intended to provide a rotating shaft of a vertical axis wind turbine generator to solve the problems of heavy weight and instability of the rotating shaft of the above-mentioned large vertical axis wind turbine generator set made of steel.

[0006] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a rotating shaft of a vertical axis wind turbine, comprising a plurality of axis units, which are axially connected in sequence to form a rotating shaft, the axis unit comprising an axis tube, both ends of which are connected with flanges through joints, the axis unit is divided into a long axis and a short axis, the length of the axis tube of the long axis is more than 10 times the length of the short axis, the long axis and the short axis are alternately connected to form the rotating shaft, the axis tube of the long axis is made of carbon fiber, and the joints, flanges and the axis tube of the short axis are all made of metal.

[0007] Preferably, as an improvement, the long shaft joint and the shaft tube are manufactured in a one-to-one pair, the long shaft joint has a connecting section that is interference fit in the shaft tube, and the long shaft joint is provided with a step for positioning the end of the shaft tube.

[0008] Preferably, as an improvement, an adhesive is coated between the connecting section of the long shaft joint and the inner wall of the shaft tube, and the adhesive is one of epoxy resin glue, polyurethane glue, acrylate glue, cyanoacrylate glue, and silicone glue.

[0009] Preferably, as an improvement, at least two groups of fastening screw holes are axially provided on the joint connecting section of the long shaft, and the fastening screw holes of adjacent groups are staggered along the circumference. A through hole matching the fastening screw hole is provided at the end of the shaft tube of the long shaft, and a fastener connected to the fastening screw hole is passed through the through hole.

[0010] Preferably, as an improvement, the wall thickness of the shaft tube on the outer side of the long shaft joint connecting section is greater than the wall thickness of the middle section of the shaft tube.

[0011] Preferably, as an improvement, a shaft shoulder is provided on the joint of the short shaft, the shaft shoulder is interference fit with the shaft tube of the short shaft, and the shaft shoulder is fixed to the end of the shaft tube by welding along the circumference.

[0012] Preferably, as an improvement, the joint is in the shape of a circular tube, and the end portion where the joint is connected to the flange is provided with a plurality of connecting teeth distributed along the circumference, the connecting teeth are provided with connecting screw holes, the flange is provided with a plurality of connecting grooves corresponding to the connecting teeth, and each connecting groove is provided with a step hole on the back side, and a fastener connected to the connecting screw hole is passed through the step hole.

[0013] Preferably, as an improvement, the wall thickness of the shaft tube of the short axis is greater than the wall thickness of the shaft tube of the long axis.

[0014] The principle and advantages of this scheme are: in actual application, the rotating shaft is divided into several long shafts and short shafts, and the long shaft accounts for a large proportion, as the main axial support of the wind wheel, and only the shorter short shaft is used between the two long shafts as the rotating support structure of the wind wheel blades. The main structural shaft tube of the long shaft is made of carbon fiber, which is stronger than steel, has a lower density than aluminum, is more corrosion-resistant than stainless steel, and is more resistant to high temperatures than heat-resistant steel. It also has the advantages of electrical conductivity, heat transfer, and a small expansion coefficient. After our actual test, it can meet the torsional strength requirements of more than 15000N.m. In addition, in terms of diameter and length, the production process of the shaft tube made of carbon fiber material can also meet the manufacturing requirements. At the same time, under the same size conditions, the weight advantage of the carbon fiber shaft tube is also obvious: if the length of each rotating shaft of the wind turbine set is 31 meters, the two sets need a total of 62 meters, and the length of the pipe needs to be 57.4 meters. Compared with steel, the solution using carbon fiber materials can reduce the weight by at least 1562Kg. In addition, according to conventional technology, a 31-meter-long rotating shaft is designed in 3 sections, each section is at least 10 meters, which is difficult to manufacture, install and transport, and the cost is high. This solution can be changed to a 5-section design for each group, with each section of the long shaft being about 5.78 meters, and a short shaft is set between the two long shafts, on which the bearing support system is installed. This design is convenient for manufacturing, transportation and installation, and improves the rotating system and stability.

[0015] However, there is a difficulty in using carbon fiber materials, that is, it is difficult to connect with steel parts. Because of the non-metallic characteristics of carbon fiber materials themselves, coupled with limitations such as length and manufacturing precision, they cannot be arbitrarily cut and welded like metals, and the size is unstable. The inner diameter of each shaft is different, which further increases the difficulty of connection. This solution adopts the method of pairing metal joints with carbon fiber shaft tubes one by one to solve the problem of inconsistent sizes; it also adopts the interference fit method and applies high-strength structural adhesive on the circumferential surface to increase the stability and strength of the connection; and then cooperates with the method of arranging fastening bolts in a circumferential staggered manner to avoid damaging the effective strength of the carbon fiber tube as much as possible. The rotating shaft of this solution adopts a combination of carbon fiber long shaft and metal short shaft. Compared with the steel rotating shaft of conventional technology, this solution has the characteristics of light weight, reliable connection, convenient manufacturing, transportation and installation, strong corrosion resistance, high operating stability, low wind resistance, and high wind energy conversion rate.

[0016] The present invention also provides a method for using a rotating shaft of a vertical axis wind turbine generator to solve the problem that existing large vertical axis wind turbine generator sets are difficult to ensure the mechanical properties of the rotating shaft while effectively controlling the weight of the transmission system and ensuring the stability of the entire system.

[0017] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a method for using a rotating shaft of a vertical axis wind turbine, using the rotating shaft of the vertical axis wind turbine as the central axis of the vertical axis wind turbine supporting the wind rotor blades, comprising: manufacturing and assembling a carbon fiber shaft tube, a metal shaft tube, a joint, and a flange into a long shaft and a short shaft in a production workshop, first assembling a bearing assembly on the shaft tube and then assembling the joint and the flange during the short shaft assembly, transporting the long shaft and the short shaft to the vertical axis wind turbine installation site respectively, connecting the short shaft between the two long shafts with fasteners to form a rotating shaft, and installing the wind rotor of the vertical axis wind turbine on the bearing assembly of the short shaft.

[0018] Preferably, as an improvement, the rotating shafts are divided into two groups, each group of rotating shafts is 31 meters long, each group of rotating shafts is divided into 5 sections, each section has a long axis length of 5.7 meters, and each section has a short axis length of 0.5 meters. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of the long axis in Example 1 of the present invention.

[0020] Figure 2 This is a schematic diagram of the structure of the short axis in Example 1 of the present invention. DETAILED DESCRIPTION

[0021] The following is further described in detail through specific implementation methods:

[0022] The reference numerals in the drawings of the specification include: flange 1, joint 2, shaft tube 3, fastening screw hole 4, stainless steel ball head hexagon socket bolt 5, hexagon socket bolt 6, connecting tooth 7, step 8, and shaft shoulder 9.

[0023] Embodiment 1, basically as attached Figure 1 , Figure 2 As shown: a rotating shaft of a vertical axis wind turbine, including a plurality of shaft units, which are axially connected in sequence to form a rotating shaft, and the shaft unit includes a shaft tube 3, and both ends of the shaft tube 3 are connected to flanges 1 through joints 2.

[0024] The shaft unit is divided into a long shaft and a short shaft. The shaft tube 3 of the long shaft is 5.7m long and is made of carbon fiber. The joint 2 and the flange 1 are made of metal. The joint 2 of the long shaft is manufactured in pairs with the shaft tube 3. The joint 2 of the long shaft has a connecting section that is interference-fitted in the shaft tube 3. An adhesive is coated between the connecting section and the inner wall of the shaft tube 3. The adhesive is one of epoxy resin glue, polyurethane glue, acrylate glue, cyanoacrylate glue, and silicone glue. The wall thickness of the shaft tube 3 outside the connecting section is greater than the wall thickness of the middle section of the shaft tube 3. Two groups of fastening screw holes 4 are axially arranged on the connecting section. The fastening screw holes 4 of adjacent groups are staggered along the circumference. The end of the shaft tube 3 of the long shaft is provided with a through hole matched with the fastening screw hole 4. A stainless steel ball head hexagon socket bolt 5 connected to the fastening screw hole 4 is penetrated in the through hole. A stainless steel flat washer is provided between the stainless steel ball head hexagon socket bolt 5 and the shaft tube 3. A step 8 for positioning the end of the shaft tube 3 is provided on the joint 2 of the long shaft.

[0025] The length of the short axis is 0.5m, and the wall thickness of the shaft tube 3 of the short axis is greater than that of the shaft tube 3 of the long axis. A shoulder 9 is provided on the joint 2 of the short axis, and the shoulder 9 and the shaft tube 3 of the short axis have an interference fit, and the shoulder 9 and the end of the shaft tube 3 are fixed by welding along the circumference.

[0026] The joint 2 is in the shape of a circular tube, and the end portion where the joint 2 is connected to the flange 1 is provided with a plurality of connecting teeth 7 distributed along the circumference, and the connecting teeth 7 are provided with connecting screw holes, and the flange 1 is provided with a plurality of connecting grooves corresponding to the connecting teeth 7, and a step 8 hole is provided on the back side of each connecting groove, and a hexagon socket bolt 6 connected to the connecting screw hole is passed through the step 8 hole, and a spring washer is provided between the hexagon socket bolt 6 and the step 8 hole.

[0027] Embodiment 2, a method for using a rotating shaft of a vertical axis wind turbine, wherein the rotating shaft of the vertical axis wind turbine of embodiment 1 is used as the central shaft of the vertical axis wind turbine to support the rotor blades, and the specific implementation process is as follows: In the production workshop, the carbon fiber shaft tube 3, the metal shaft tube 3, the joint 2, and the flange 1 are manufactured and assembled into a long shaft and a short shaft, and the rotating shaft is divided into two groups, each group of rotating shafts is 31 meters long, and each group of rotating shafts is divided into 5 sections, each section of the long shaft is 5.7 meters long, and each section of the short shaft is 0.5 meters long. During the assembly of the short shaft, the bearing assembly is first assembled on the shaft tube 3, and then the joint 2 and the flange 1 are assembled. The long shaft and the short shaft are transported to the installation site of the vertical axis wind turbine respectively, and the short shaft is connected between the two long shafts with fasteners to form a rotating shaft, and the wind wheel of the vertical axis wind turbine is installed on the bearing assembly of the short shaft.

[0028] The present invention divides the rotating shaft into several long shafts and short shafts, and the long shaft accounts for a large proportion, which serves as the main axial support of the wind wheel. Only the shorter short shaft is used between the two long shafts as the rotating support structure of the wind wheel blades. The main structural shaft tube 3 of the long shaft is made of carbon fiber material, which is stronger than steel, has a lower density than aluminum, is more corrosion-resistant than stainless steel, and is more resistant to high temperatures than heat-resistant steel. It also has the advantages of electrical conductivity, heat transfer, and a small expansion coefficient. According to our actual tests, it can meet the torsional strength requirements of more than 15000N.m. In addition, in terms of diameter and length, the production process of the shaft tube 3 made of carbon fiber material can also meet the manufacturing requirements. At the same time, under the same size conditions, the weight advantage of the carbon fiber shaft tube 3 is also obvious: if the length of the rotating shaft of each wind turbine group is 31 meters, the two groups need a total of 62 meters, and the pipe length needs to be 57.4 meters. Compared with steel, the solution using carbon fiber materials can reduce the weight by at least 1562Kg. The problem of inconsistent sizes is solved by pairing the metal joint 2 with the carbon fiber shaft tube 3 one by one. The interference fit method is adopted, and high-strength structural adhesive is applied on the circumferential surface to increase the connection stability and strength. The method of arranging the fastening bolts in a circumferential staggered manner is combined to avoid damaging the effective strength of the carbon fiber tube as much as possible. In addition, according to conventional technology, the 31-meter-long rotating shaft is designed in 3 sections, each section is at least 10 meters, and manufacturing, installation and transportation are all difficult and expensive. This solution can be changed to design each group in 5 sections, each section has a long axis of about 5.78 meters, and a short axis is set between the two long axes, and a bearing support system is installed on the short axis. This design not only facilitates manufacturing, transportation and installation, but also improves the rotation system and stability.

[0029] The rotating shaft of the present invention adopts a combination of a carbon fiber long shaft and a metal short shaft. Compared with the steel rotating shaft of conventional technology, this solution has the characteristics of light weight, reliable connection, convenient manufacturing, transportation and installation, strong corrosion resistance, high operating stability, low wind resistance, and high wind energy conversion rate.

[0030] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A vertical axis wind turbine rotating shaft, characterized in that: It includes several shaft units, which are axially connected in sequence to form a rotating shaft. The shaft unit includes a shaft tube. Both ends of the shaft tube are connected with flanges through joints. The shaft unit is divided into a long axis and a short axis. The shaft tube length of the long axis is more than 10 times the length of the short axis. The long axis and the short axis are alternately connected to form the rotating shaft. The shaft tube of the long axis is made of carbon fiber, and the joints, flanges and shaft tube of the short axis are all made of metal.

2. The vertical axis wind turbine rotating shaft according to claim 1, characterized in that: The long shaft joint is manufactured in a one-to-one matching manner with the shaft tube. The long shaft joint has a connecting section which is interference-fitted in the shaft tube. The long shaft joint is provided with a step for positioning the end of the shaft tube.

3. The vertical axis wind turbine rotating shaft according to claim 2, characterized in that: An adhesive is coated between the connecting section of the long shaft joint and the inner wall of the shaft tube. The adhesive is one of epoxy resin glue, polyurethane glue, acrylate glue, cyanoacrylate glue and silicone glue.

4. The vertical axis wind turbine rotating shaft according to claim 3, characterized in that: The joint connection section of the long shaft is provided with no less than two groups of fastening screw holes along the axial direction, and the fastening screw holes of adjacent groups are arranged circumferentially staggered. The end of the shaft tube of the long shaft is provided with a through hole matching the fastening screw hole, and a fastener connected to the fastening screw hole is passed through the through hole.

5. The vertical axis wind turbine rotating shaft according to claim 4, characterized in that: The wall thickness of the shaft tube outside the connecting section of the long shaft joint is greater than the wall thickness of the middle section of the shaft tube.

6. The vertical axis wind turbine rotating shaft according to claim 1, characterized in that: A shaft shoulder is arranged on the joint of the short shaft, and the shaft shoulder is interference fit with the shaft tube of the short shaft, and the shaft shoulder is fixed to the end of the shaft tube by welding along the circumference.

7. A vertical axis wind turbine rotating shaft according to any one of claims 1 to 6, characterized in that: The joint is in the shape of a circular tube, and the end portion where the joint is connected to the flange is provided with a plurality of connecting teeth distributed along the circumference, the connecting teeth are provided with connecting screw holes, the flange is provided with a plurality of connecting grooves corresponding to the connecting teeth, and each connecting groove is provided with a step hole on the back side, and a fastener connected to the connecting screw hole is passed through the step hole.

8. The vertical axis wind turbine rotating shaft according to claim 7, characterized in that: The wall thickness of the shaft tube of the short axis is greater than the wall thickness of the shaft tube of the long axis.

9. A method for using a rotating shaft of a vertical axis wind turbine, characterized in that: The vertical axis wind turbine rotating shaft described in any one of claims 1 to 8 is used as the central axis of the vertical axis wind turbine supporting the rotor blades, comprising: manufacturing and assembling a carbon fiber shaft tube, a metal shaft tube, a joint, and a flange into a long axis and a short axis in a production workshop, first assembling the bearing assembly on the shaft tube and then assembling the joint and the flange during the short axis assembly process, transporting the long axis and the short axis to the vertical axis wind turbine installation site respectively, connecting the short axis between the two long axis with fasteners to form a rotating shaft, and installing the rotor of the vertical axis wind turbine on the bearing assembly of the short axis.

10. The method for using the rotating shaft of a vertical axis wind turbine according to claim 9, characterized in that: The rotating axes are divided into two groups, each group of rotating axes is 31 meters long, and each group of rotating axes is divided into 5 sections, each section has a long axis of 5.7 meters long and each section has a short axis of 0.5 meters long.

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