A fan impeller welding device

Abstract

The application relates to a fan welding technical field, in particular to a fan impeller welding device, which comprises a welding manipulator and a rotating station, the device further comprises a supporting mechanism arranged on the rotating station and used for limiting and cooling the blades spot-welded on the wheel disc, the arc-shaped plate is used for shielding and protecting the two sides of the welded blade, the welding slag can be prevented from adhering to the wheel disc and the blade, the quality of each blade is guaranteed to be consistent with the original design, the difficulty of the later dynamic balance correction is reduced, meanwhile, the limiting plate can be used for clamping and limiting the blade during welding, the blade can be prevented from being skewed and deformed due to high temperature welding, the balance design of the impeller is further guaranteed, and the overall production efficiency of the impeller is indirectly improved, the limiting plate can be used for shielding the blade being welded, and the welding slag can be prevented from adhering to other positions outside the welding points of the blade.

Description

Technical Field

[0001] This invention relates to the field of wind turbine welding technology, specifically a wind turbine impeller welding device. Background Technology

[0002] As the core aerodynamic component of a fan, the manufacturing quality of the impeller directly determines the performance, efficiency, and reliability of the entire machine. Typical centrifugal or axial impellers are usually welded together from a disc and multiple blades evenly distributed circumferentially. After welding, the impeller must undergo strict dynamic balancing to eliminate the imbalance of centrifugal force caused by its uneven mass distribution. Dynamic balancing accuracy is a core indicator to ensure the long-term stable, low-vibration, and low-noise operation of the fan.

[0003] Currently, to improve production efficiency and consistency, the use of welding robots for automated welding of impellers has become an industry trend. A typical automated welding process is as follows: First, the blades need to be pre-spot-welded to the designated positions on the impeller to ensure that the relative angle and position between the blades and the impeller meet the design requirements. Then, the welding robot automatically welds the joint weld between the blades and the impeller according to the preset program path to achieve the final permanent connection.

[0004] However, despite the widespread application of automated welding, existing technologies still have significant drawbacks when welding impellers with densely arranged blades. On the one hand, the localized high heat generated during welding can easily cause thermal deformation and skewness of the blades, which directly disrupts the impeller's balance design and makes subsequent dynamic balancing extremely difficult. On the other hand, the welding slag that splashes during welding can easily adhere to the blade surface, directly altering the impeller's original mass distribution and introducing uncontrollable imbalances. Both of these problems can seriously affect the fan's vibration, noise, and service life.

[0005] Therefore, developing a welding device that can simultaneously provide precise support to prevent deformation and effectively shield to prevent weld slag adhesion has become an urgent technical requirement for improving the welding quality and production efficiency of wind turbine impellers. Summary of the Invention

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a wind turbine impeller welding device, including a welding robot and a rotating station, the device also includes a support mechanism set on the rotating station for limiting and cooling the blades spot-welded on the impeller.

[0007] The support mechanism includes an outer shaft and an inner shaft mounted on a rotating station via a lifting assembly. The outer shaft and the inner shaft are detachably connected by a connecting assembly to two arc-shaped plates for protecting two adjacent blades to be welded, and two limiting plates for clamping the blades. The connecting assembly is used to move the arc-shaped plates and the limiting plates simultaneously.

[0008] The limiting plate has a hollow structure. The end of the limiting plate near the wheel axis is provided with a water inlet, and the end of the limiting plate away from the wheel axis is provided with a water outlet. During welding, circulating cooling water is introduced into the limiting plate and the blade to be welded is clamped by the limiting plate, thereby cooling the blade and limiting its position at the same time.

[0009] High-quality blade welding operations are achieved by protecting, cooling, and limiting the blades to be welded from adjacent blades.

[0010] Preferably, the outer shaft and the inner shaft are nested together and rotate in opposite directions at the same speed.

[0011] Preferably, the lifting assembly includes a lifting frame that is slidably mounted on a rotating station, and a hydraulic cylinder is provided between the lifting frame and the rotating station.

[0012] Preferably, the lower end of the outer shaft is rotatably connected to the middle of the lifting frame, and the upper end of the inner shaft is rotatably connected to the upper side of the lifting frame.

[0013] Preferably, driven bevel gears are fixedly installed on the upper side of both the outer shaft and the upper side of the inner shaft, and an active bevel gear that meshes with both driven bevel gears simultaneously is rotatably connected to the lifting frame.

[0014] Preferably, a servo geared motor is installed on the lifting frame, and the output shaft of the servo geared motor is fixedly connected to the driving bevel gear, which is located between two driven bevel gears.

[0015] Preferably, the connecting assembly includes four connecting brackets sleeved on the outer shaft, with the first and third connecting brackets fixedly connected to the inner shaft from top to bottom, and the second and fourth connecting brackets fixedly connected to the outer shaft from top to bottom.

[0016] Preferably, studs are fixedly provided at the ends of the arc-shaped plate and the limiting plate near the axis of the wheel. The studs are inserted into the corresponding connecting frame, and then the nuts are tightened to fix the arc-shaped plate, the limiting plate and the corresponding connecting frame together.

[0017] Preferably, the arc-shaped plate is L-shaped in general, with the vertical section of the arc-shaped plate protecting the blade and the horizontal section of the arc-shaped plate protecting the wheel.

[0018] Preferably, the lower part of the limiting plate has an inclined structure.

[0019] The beneficial effects of this invention are as follows: First, the invention uses an arc-shaped plate to shield and protect both sides of the welded blades, which can prevent welding slag from adhering to the impeller and blades, thereby ensuring that the quality of each blade is consistent with the original design after the impeller is welded, reducing the difficulty of subsequent dynamic balancing correction. At the same time, the limiting plate can be used to clamp and limit the blades during welding, preventing the blades from skewing and deforming due to the high temperature of welding, further ensuring the balance design of the impeller, and indirectly improving the efficiency of subsequent dynamic balancing correction and the overall production efficiency of the impeller.

[0020] Second, the present invention uses a limiting plate to clamp the blade being welded while also protecting the blade, preventing weld slag from adhering to other positions outside the welding point of the blade, reducing the difficulty of cleaning and shaping the weld later. At the same time, the circulating cooling water inside the limiting plate can continuously cool the non-welding positions of the blade, thereby quickly cooling the blade after welding and making it firmly connected to the wheel, further preventing the blade from tilting.

[0021] Third, the present invention adopts an L-shaped structure design with an arc plate, which can not only protect the blades through the vertical section of the arc plate, but also protect the wheel through the horizontal section of the arc plate, further enhancing the function of preventing weld slag adhesion.

[0022] Fourth, this invention uses studs and nuts on the arc-shaped plate and the limiting plate to lock together, so that the connecting arc-shaped plate, the limiting plate and the corresponding connecting frame can be detachably fixed together. Thus, when dealing with different models of impellers, production can be quickly adjusted by replacing the corresponding arc-shaped plate and the limiting plate. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0025] Figure 2 This is a structural schematic diagram of the rotating workstation, lifting frame, arc plate, and limiting plate in this invention.

[0026] Figure 3 This is a partial sectional view of the outer shaft, inner shaft, driven bevel gear, and driving bevel gear in this invention.

[0027] Figure 4 This is a partial structural diagram of the connecting frame, arc plate, servo reduction motor and limiting plate in this invention.

[0028] Figure 5 This is a partial sectional view of the outer shaft, inner shaft, and connecting frame in this invention.

[0029] Figure 6This is a schematic diagram of the structure of the inner shaft and the connecting frame connected to it in this invention.

[0030] Figure 7 This is a schematic diagram of the structure of the arc-shaped plate, the limiting plate, and the connecting frame in this invention.

[0031] Figure 8 This is a schematic diagram of the connecting frame and the arc-shaped plate in this invention.

[0032] Figure 9 This is a partial cross-sectional view of the connecting frame and the limiting plate in this invention.

[0033] In the diagram: 1. Welding robot; 2. Rotary station; 3. Support mechanism; 31. Lifting assembly; 32. Outer shaft; 33. Inner shaft; 34. Connecting assembly; 35. Arc plate; 36. Limiting plate; 311. Lifting frame; 312. Hydraulic cylinder; 321. Driven bevel gear; 322. Driven bevel gear; 323. Servo geared motor; 341. Connecting frame. Detailed Implementation

[0034] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in the art or in accordance with the product manual.

[0035] See Figure 1 , Figure 2 and Figure 3 A wind turbine impeller welding device includes a welding robot 1 and a rotating station 2. The device also includes a support mechanism 3 set on the rotating station 2 for limiting and cooling the blades spot-welded on the impeller.

[0036] In this embodiment, the rotary station 2 is a workbench commonly used by those skilled in the art. During welding, the wheel is placed and locked on the rotary station 2. The upper side of the wheel is pre-spot-welded with evenly distributed blades. Then, the welding robot 1 automatically welds the weld seams on both sides of a blade that is closest to itself. After welding one blade, the rotary station 2 automatically rotates the wheel so that another blade to be welded corresponds to the position of the welding robot 1. Then, the welding robot 1 welds another blade. The above steps are repeated until all blades are welded onto the wheel.

[0037] In this embodiment, the welding robot 1 adopts the currently common automated control method. The welding robot 1 is also equipped with a currently common laser guidance and correction system, which enables the welding robot 1 to drive the welding torch to move automatically along the weld seam of the blade and weld. When the weld seam on one side of the blade is completed, the welding robot 1 automatically moves the welding torch to the weld seam on the other side of the blade and welds, thereby completing the firm welding of the blade.

[0038] It should be noted that in this embodiment, multiple clamps simultaneously hold the wheel and the rotating station 2, so that the rotating station 2 can drive the wheel to rotate simultaneously, thereby replacing the blades for welding. The clamps are not shown in the figure.

[0039] See Figure 1 , Figure 2 and Figure 4 The support mechanism 3 includes an outer shaft 32 and an inner shaft 33 mounted on the rotating station 2 via a lifting assembly 31. The outer shaft 32 and the inner shaft 33 are detachably connected via a connecting assembly 34 to two arc-shaped plates 35 for protecting two adjacent blades to be welded, and two limiting plates 36 for clamping the blades. The connecting assembly 34 is used to move the arc-shaped plates 35 and the limiting plates 36 simultaneously.

[0040] During welding, two limiting plates 36 are positioned on both sides of the blade to be welded, and two arc-shaped plates 35 are positioned outside the two limiting plates 36. The blade to be welded is then clamped by the two limiting plates 36, thereby limiting the blade and preventing it from tilting due to high temperature during welding. At the same time, the two arc-shaped plates 35 abut against the sides of the two adjacent blades to be welded, thus shielding the two adjacent blades. When the limiting plates 36 clamp the blade to be welded, they can also shield the upper part of the blade to be welded, thereby preventing welding spatter from adhering to the blade. This ensures that the quality of each blade is consistent with the original design, guarantees the balance design of the impeller, and reduces the difficulty of subsequent dynamic balancing correction.

[0041] To facilitate welding of the blade at the welding position while simultaneously clamping and limiting the blade to be welded, the present invention designs the following structure: (See attached diagram) Figure 2 , Figure 4 , Figure 7 and Figure 9 The lower part of the limiting plate 36 has a sloping structure, and there is a gap between the lower part of the limiting plate 36 and the wheel. During welding, the welding gun moves along the trajectory of the connection between the blade and the wheel. The lower side of the limiting plate 36 is located above the weld. The sloping lower part of the limiting plate 36 reduces the space occupied, making it easier for the welding gun to approach the weld for precise welding.

[0042] To improve the protection and isolation capability of the arc-shaped plate 35 against weld spatter during welding, the present invention designs the following structure: (See reference) Figure 2 , Figure 4 , Figure 7 and Figure 8 The arc plate 35 is L-shaped. The vertical section of the arc plate 35 protects the blades, and the horizontal section of the arc plate 35 protects the impeller. During welding, the weld slag that splashes out of the weld falls onto the horizontal section of the arc plate 35 or adheres to the side of the limiting plate 36 or the vertical section of the arc plate 35, which further ensures the balance design of the impeller and indirectly improves the efficiency of subsequent dynamic balance correction and the overall production efficiency of the impeller.

[0043] See Figure 7 and Figure 9 The limiting plate 36 has a hollow structure. The end of the limiting plate 36 near the wheel axis is provided with a water inlet, and the end of the limiting plate 36 away from the wheel axis is provided with a water outlet. During welding, circulating cooling water is introduced into the limiting plate 36, and the blade to be welded is clamped by the limiting plate 36, thereby cooling the blade and limiting its position at the same time.

[0044] Before welding, connect the outlet to the inlet of the water supply equipment and the inlet to the outlet of the water supply equipment. During welding, start the water supply equipment to continuously send circulating cooling water into the limiting plate 36, so that the limiting plate 36 can continuously cool the non-welded parts of the blade, thereby quickly cooling the blade after welding and making it firmly connected to the wheel. This further prevents the blade from tilting due to its own weight or vibration after welding and losing protection, and ensures that the position and angle of the blade maintain the original design. The water supply equipment is not shown in the figure.

[0045] To quickly clamp and limit the position of the blades to be welded, the present invention designs the following structure: (See attached diagram) Figure 2 , Figure 3 , Figure 4 and Figure 5 The outer shaft 32 and the inner shaft 33 are nested together and rotate with each other. The lifting assembly 31 includes a lifting frame 311 that is slidably mounted on the rotating station 2. The lower end of the outer shaft 32 is rotatably connected to the middle of the lifting frame 311, and the upper end of the inner shaft 33 is rotatably connected to the upper side of the lifting frame 311. A hydraulic cylinder 312 is provided between the lifting frame 311 and the rotating station 2.

[0046] See Figure 2 , Figure 3 and Figure 4Both the upper side of the outer shaft 32 and the upper side of the inner shaft 33 are fixedly installed with driven bevel gears 321. The lifting frame 311 is rotatably connected with an active bevel gear 322 that meshes with both driven bevel gears 321. The lifting frame 311 is equipped with a servo gear reducer motor 323. The output shaft of the servo gear reducer motor 323 is fixedly connected to the active bevel gear 322. The active bevel gear 322 is located between the two driven bevel gears 321.

[0047] In this embodiment, the outer shaft 32 is connected to a front limiting plate 36 and a rear arc plate 35 through a connecting assembly 34, so that when the outer shaft 32 rotates, it drives the limiting plate 36 and the arc plate 35 to rotate synchronously. Similarly, the inner shaft 33 is connected to a rear limiting plate 36 and a front arc plate 35 through a connecting assembly 34, and the inner shaft 33 rotates synchronously with the front limiting plate 36 and the arc plate 35.

[0048] During welding, the front limiting plate 36 and the arc plate 35 are located at the front of the blade to be welded, and the rear limiting plate 36 and the arc plate 35 are located at the rear of the blade to be welded. The servo reduction motor 323 is started to rotate forward, so that the servo reduction motor 323 drives the two driven bevel gears 321 to rotate synchronously in opposite directions through the active bevel gear 322. The two driven bevel gears 321 then drive the outer shaft 32 and the inner shaft 33 to rotate synchronously in opposite directions at the same speed.

[0049] This causes the outer shaft 32 to rotate the front limiting plate 36 and the rear arc plate 35 backward, while the inner shaft 33 causes the rear limiting plate 36 and the front arc plate 35 to rotate forward. This causes the front limiting plate 36 to abut against the front side of the blade to be welded, and the rear limiting plate 36 to abut against the rear side of the blade to be welded. Thus, the two limiting plates 36 clamp and limit the blade to be welded, preventing it from tilting.

[0050] At the same time, the vertical section of the rear arc plate 35 abuts against the front side of the rear blade of the blade to be welded, and the vertical section of the front arc plate 35 abuts against the rear side of the front blade of the blade to be welded. Thus, the two arc plates 35 protect the two blades at adjacent positions of the blades to be welded, preventing the spattered welding slag from sticking to the impeller. After the welding is completed, the servo reduction motor 323 is started to reverse, so that the arc plate 35 and the limiting plate 36 move away from the blade.

[0051] Then, the extension section of the hydraulic cylinder 312 extends, driving the lifting frame 311 to move upward. This causes the lifting frame 311 to drive the outer shaft 32 and inner shaft 33 to move upward synchronously. The outer shaft 32 and inner shaft 33, through the connecting assembly 34, drive the arc plate 35 and the limiting plate 36 to move upward synchronously. This causes the arc plate 35 and the limiting plate 36 to move to the upper part of the impeller. Then, by rotating the angle of two adjacent blades of the wheel at the rotating station 2, the new blade to be welded is aligned with the welding position. Then, the extension section of the hydraulic cylinder 312 is retracted, and then the servo reduction motor 323 is started again to rotate forward. The principle is the same as above, so that all the blades are welded.

[0052] It should be noted that when the servo geared motor 323 reverses, it is only necessary to move the arc plate 35 and the limiting plate 36 by a small distance to create a gap between the arc plate 35, the limiting plate 36 and the blade, and at this time the horizontal section of the arc plate 35 does not contact the blade.

[0053] It is worth noting that the arc plate 35 and the limiting plate 36 are manufactured according to the blade, so the arc plate 35 and the limiting plate 36 can fit the blade completely for clamping, limiting and protecting.

[0054] To facilitate quick replacement of the arc-shaped plate 35 and the limiting plate 36 according to different impeller models, the present invention is designed with the following structure: (See attached diagram) Figure 1 , Figure 4 , Figure 5 and Figure 6 The connecting assembly 34 includes four connecting brackets 341 sleeved on the outer shaft 32. The first and third connecting brackets 341 from top to bottom are fixedly connected to the inner shaft 33, and the second and fourth connecting brackets 341 from top to bottom are fixedly connected to the outer shaft 32.

[0055] See Figure 7 , Figure 8 and Figure 9 Both the arc plate 35 and the limiting plate 36 have studs fixed at one end near the wheel axis. When replacing the corresponding arc plate 35 and limiting plate 36, the studs on the arc plate 35 and the limiting plate 36 are inserted into the corresponding connecting frame 341, and then the nuts are tightened to fix the arc plate 35, the limiting plate 36 and the corresponding connecting frame 341 together, thereby completing the quick replacement of the arc plate 35 and the limiting plate 36.

[0056] In this embodiment, the first connecting frame 341 from top to bottom is connected to the front arc plate 35; the second connecting frame 341 from top to bottom is connected to the front limiting plate 36; the third connecting frame 341 from top to bottom is connected to the rear limiting plate 36; and the fourth connecting frame 341 from top to bottom is connected to the rear arc plate 35. This allows the outer shaft 32 to rotate synchronously by driving the front limiting plate 36 and the rear arc plate 35 through the second and fourth connecting frames 341 from top to bottom. Similarly, when the inner shaft 33 rotates, it drives the rear limiting plate 36 and the front arc plate 35 to rotate synchronously through the first and third connecting frames 341 from top to bottom.

[0057] It should be noted that the two connecting brackets 341 connected to the arc plate 35 are fixedly connected to the outer shaft 32 and the inner shaft 33 respectively by screw locking. The screws are not shown in the figure. Therefore, when dealing with impellers with different spacing between two adjacent blades, the screws are loosened in advance so that the two connecting brackets 341 connected to the arc plate 35 are rotatably connected to the outer shaft 32 and the inner shaft 33 respectively. Then, the outer shaft 32 and the inner shaft 33 are rotated so that the limiting plate 36 clamps and limits the blades. The arc plate 35 is then manually moved to fit against the two adjacent blades. Finally, the screws are tightened to complete the preset position of the arc plate 35.

[0058] It is worth noting that the replacement of the arc plate 35 and the limiting plate 36, and the adjustment of the position of the arc plate 35 only require one manual adjustment. After that, large-scale automatic welding operations can be carried out for long-term use without the need for further adjustment, thus ensuring production efficiency.

[0059] In summary, although this invention adds structures such as the arc plate 35 and the limiting plate 36 to the traditional welding equipment, it achieves precise positioning and all-round protection of the blades by shielding and protecting adjacent blades with the arc plate 35 and clamping, limiting, and circulating cooling with the limiting plate 36. This effectively prevents blade skewing and deformation caused by high welding temperatures and changes in mass distribution caused by weld spatter, greatly reducing the difficulty and workload of dynamic balancing correction of the impeller in the later stage, and significantly improving the overall production efficiency of impeller manufacturing. Therefore, this invention can quickly balance the initial investment in equipment and modification costs in a short period of time, bringing stable and reliable quality assurance and considerable economic benefits to the large-scale automated welding production of wind turbine impellers.

[0060] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0061] Furthermore, the terms "first," "second," "number one," and "number two" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first," "second," "number one," or "number two" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0062] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0063] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A welding device for a wind turbine impeller, comprising a welding robot and a rotating station, characterized in that, The device also includes a support mechanism set on the rotating station for limiting and cooling the blades spot-welded to the wheel. The support mechanism includes an outer shaft and an inner shaft set on a rotating station via a lifting assembly. The outer shaft and the inner shaft are detachably connected by a connecting assembly to two arc-shaped plates for protecting two adjacent blades to be welded, and two limiting plates for clamping the blades. The connecting assembly is used to move the arc-shaped plates and the limiting plates simultaneously. The limiting plate has a hollow structure. The end of the limiting plate near the wheel axis is provided with a water inlet, and the end of the limiting plate away from the wheel axis is provided with a water outlet. During welding, circulating cooling water is introduced into the limiting plate and the blade to be welded is clamped by the limiting plate, thereby cooling the blade and limiting its position at the same time. High-quality blade welding operations are achieved by protecting, cooling, and limiting the blades to be welded from adjacent blades.

2. The fan impeller welding device according to claim 1, characterized in that, The outer shaft and the inner shaft are nested together and rotate in opposite directions at the same speed.

3. The fan impeller welding device according to claim 1, characterized in that, The lifting assembly includes a lifting frame that is slidably mounted on a rotating station, and a hydraulic cylinder is provided between the lifting frame and the rotating station.

4. The fan impeller welding device according to claim 3, characterized in that, The lower end of the outer shaft is rotatably connected to the middle of the lifting frame, and the upper end of the inner shaft is rotatably connected to the upper side of the lifting frame.

5. The fan impeller welding device according to claim 3, characterized in that, Both the upper side of the outer shaft and the upper side of the inner shaft are fixedly installed with driven bevel gears, and the lifting frame is rotatably connected with an active bevel gear that meshes with both driven bevel gears simultaneously.

6. The fan impeller welding device according to claim 5, characterized in that, The lifting frame is equipped with a servo geared motor, the output shaft of which is fixedly connected to the driving bevel gear, which is located between two driven bevel gears.

7. The fan impeller welding device according to claim 1, characterized in that, The connecting assembly includes four connecting brackets sleeved on the outer shaft. The first and third connecting brackets from top to bottom are fixedly connected to the inner shaft, and the second and fourth connecting brackets from top to bottom are fixedly connected to the outer shaft.

8. The fan impeller welding device according to claim 7, characterized in that, Both the arc-shaped plate and the limiting plate have studs fixedly installed at the ends near the wheel axis. The studs are inserted into the corresponding connecting frames, and then the nuts are tightened to fix the arc-shaped plate, the limiting plate and the corresponding connecting frames together.

9. A fan impeller welding device according to claim 1, characterized in that, The arc-shaped plate is L-shaped in general. The vertical section of the arc-shaped plate protects the blades, and the horizontal section of the arc-shaped plate protects the wheel.

10. A fan impeller welding device according to claim 1, characterized in that, The lower part of the limiting plate has an inclined structure.

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