Axial flow fan

Abstract

An impeller of the axial flow fan comprises a hub in transmission connection with an output shaft of a motor, equidistant mounting grooves are formed in the peripheral side of the hub, and blades are matched with the mounting grooves in an inserted mode through connecting roots. The positioning structure is composed of a positioning groove, a positioning protruding strip, a locking strip and a locking groove and can lock the installation angle of the blade and the hub. The locking structure comprises a fixing bottom plate, a fixing ring and a locking ring cover, and firm installation and convenient disassembly of the blades are achieved. A movable counterweight group is arranged in an inner cavity of the hub, and a dynamic balance testing assembly is arranged on the machine shell, comprises a piezoelectric vibration sensor, a main control module and a data terminal and is used for monitoring and correcting dynamic balance. According to the axial flow fan, convenient disassembly and assembly, accurate positioning and dynamic balance adjustment are achieved, the performance and practicability are improved, and the maintenance and transportation cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of fans, and particularly to an axial flow fan. Background Art

[0002] Axial flow fans are extremely widely used in daily life and industrial production. When they operate, the airflow direction is the same as the axis of the fan blades. Common electric fans and the fans of air conditioner exteriors are all fans that operate in an axial flow manner. The reason it is called "axial flow" is that the gas flows parallel to the axis of the fan inside the fan. An axial flow fan mainly consists of a fan impeller and a casing. The impeller is driven by an electric motor to rotate, realizing the transportation of gas, and during the transportation process, the gas always maintains a flow direction parallel to the axis of the fan. It is often used for ventilation and air change in general factories, warehouses, offices, residences and other places.

[0003] For existing axial flow fans, their impellers mainly consist of a hub connected to an electric motor and blades arranged around the hub. Currently, the blades are usually fixedly connected to the hub by welding. However, this welding forms a permanent connection and has many drawbacks. Once one of the blades is worn or damaged, it is necessary to damage the welding part or directly replace the entire impeller. In this way, not only does it greatly increase the difficulty of equipment maintenance, but also significantly increases the overall maintenance cost. In addition, for some medium and large-sized fans, after the blades are fixedly connected to the impeller, the overall size is relatively large. During the transportation of the impeller, this greatly limits the number of single transports and also has relatively high requirements for the transportation space, thereby increasing the difficulty and cost of transportation. Summary of the Invention

[0004] The main purpose of the present invention is to provide an axial flow fan, aiming to solve the maintenance and transportation problems caused by the welded fixation of the blades, realizing convenient disassembly and assembly, accurate positioning and dynamic balance adjustment, and improving the performance and practicality of the fan.

[0005] To achieve the above object, the present invention provides an axial flow fan, including a casing, an electric motor and an impeller, and the impeller includes: A hub, which is in transmission connection with the output shaft of the electric motor; a plurality of equally spaced installation grooves are provided on the circumferential side of the hub; A plurality of blades, the number of the plurality of blades corresponding to the number and position of the installation grooves. The blades include connection roots that are inserted and matched with the installation grooves, and the connection roots are inserted and matched with the installation grooves; A positioning structure, which is arranged between the connection root and the inner wall of the installation groove and is used to lock the installation angle between the blade and the hub; A locking structure, which is arranged between the connection root and the hub and is used to fixedly install the blade on the hub through the blade root, and the locking structure can release the fixation between the blade root and the hub to realize the disassembly of the blade.

[0006] In a possible implementation, the installation groove is cylindrically arranged, and an abutting interface is provided at one end thereof close to the blade; the connection root includes a plugging section inserted into the installation groove, and a fastening section for abutting and cooperating with the abutting interface is provided at one end of the plugging section away from the hub; the abutting interface is conically arranged, and its inner diameter gradually increases outward along the bottom of the installation groove; the outer diameter of the fastening section gradually increases outward along the bottom of the installation groove to fit with the inner wall of the abutting interface.

[0007] In a possible implementation, the positioning structure includes a plurality of positioning grooves on the inner wall of the installation groove. The positioning grooves extend along the axial direction of the installation groove, and an insertion opening is provided at one end thereof facing the abutting interface. The plurality of positioning grooves are equidistantly distributed on the inner wall of the installation groove; at least one positioning rib is further provided on the outer side wall of the plugging section, and the positioning rib is inserted and cooperated with any one of the positioning grooves.

[0008] In a possible implementation, the cross-section of the positioning groove is T-shaped, and a plurality of locking bars detachably arranged relative to the positioning groove are further inserted into the positioning groove. The number of the locking bars is less than that of the positioning grooves, and one side of the locking bar protrudes outward from the positioning groove; a plurality of locking grooves for clamping and cooperating with the locking bars are further provided on the circumferential side of the plugging section, and the plurality of locking grooves and the positioning ribs form a limiting structure corresponding to the number and position of the positioning grooves.

[0009] In a possible implementation, the locking structure includes a fixed bottom plate provided on the hub and located at the opening of the installation groove and a fixed ring provided on the circumferential side of the connection root. A locking ring cover is provided between the fixed bottom plate and the fixed ring, and the locking ring cover is fixedly connected with the fixed bottom plate by bolts.

[0010] In a possible implementation, a cylindrical support part is provided between the fixed bottom plate and the hub, and a gap is formed between the fixed bottom plate and the hub by the support part; the locking ring cover includes a left ring cover and a right ring cover which are separately arranged. Clamping ring grooves are provided on the circumferential sides of the left ring cover and the right ring cover. One side of the clamping ring groove facing the fixed bottom plate is open, and an upper abutting surface and a lower abutting surface are formed on the inner wall thereof. The upper abutting surface abuts against the upper surface of the fixed ring, and the lower abutting surface abuts against the lower surface of the fixed bottom plate.

[0011] In a possible implementation, a downward pressing surface which is conically arranged is provided on the upper abutting surface facing the direction of the clamping ring groove. The downward pressing surface is used for driving the fixed ring to move towards the fixed bottom plate when contacting with the fixed ring.

[0012] In a possible implementation, a compensation gap exists between the fixed bottom plate and the fixed ring, and a rubber layer located between the upper abutting surface and the lower abutting surface and corresponding to the position of the compensation gap is provided on the inner wall of the clamping ring groove. The thickness of the rubber layer is greater than the height of the compensation gap.

[0013] In a possible implementation, an inner cavity is provided inside the hub, and a number of weight adjustment groups are slidably arranged in the inner cavity. The number of weight adjustment groups are circumferentially distributed in the inner cavity and can move linearly from the edge of the inner cavity towards the center of the inner cavity. Further included is a dynamic balance testing component arranged on the casing. The dynamic balance testing component includes a number of piezoelectric vibration sensors arranged on the inner wall of the casing and opposite to the impeller. The piezoelectric vibration sensors are connected to a data terminal through a main control module, convert the vibration generated by the casing into a vibration signal, process it, and then send it to the data terminal.

[0014] In a possible implementation, both the left ring cover and the right ring cover are semi-circular. A horizontally arranged connecting plate is provided at one end where they face each other, and the connecting plates are fixedly connected by bolts.

[0015] In summary, the beneficial effects of this application are as follows: Compared with the prior art, this application adopts a method of inserting and mating the equally spaced mounting grooves provided on the circumferential side of the hub with the connection roots of the blades, changing the permanent connection of traditional welding, and solving the problems that when the blades are worn or damaged, it is necessary to damage the welded part or replace the impeller as a whole, greatly reducing the equipment maintenance difficulty and cost. In the positioning structure, the positioning grooves on the inner wall of the mounting groove are inserted and mated with the positioning ridges on the outer side wall of the insertion section, and a limiting structure is formed by combining the detachable locking strip and the locking groove, which can accurately lock the installation angle between the blade and the hub, ensure the installation accuracy of the impeller, improve the operation stability of the fan, and ensure the dynamic balance during the installation process. The locking structure utilizes the fixed base plate, the fixed ring, and the locking ring cover fixedly connected by bolts. In particular, the left and right ring covers which are separately arranged, and the upper and lower abutting surfaces in their clamping ring grooves are respectively abutted against the fixed ring and the fixed base plate, and the conical pressing surface of the upper abutting surface can drive the fixed ring to move towards the fixed base plate, and cooperate with the rubber layer to fill and compensate for the gap, realizing the firm fixation of the blade on the hub, and at the same time, it can be easily disassembled to remove the blade, meeting the maintenance and transportation requirements.

[0016] The inner cavity of the hub is provided with weight adjustment groups that can move linearly. Combined with the dynamic balance testing component composed of piezoelectric vibration sensors, a main control module, and a data terminal on the casing, it can monitor the vibration of the casing in real time, convert and process it into a signal and send it to the data terminal, facilitating timely adjustment of the position of the weight adjustment groups to correct the dynamic balance, and further ensuring the stable operation of the fan.

[0017] In addition, the detachable design of the blade enables the medium and large-sized fans to disassemble the blades before transportation, reducing the overall size, solving the problems of limited single transportation quantity and high requirements for transportation space during the transportation process, reducing the transportation difficulty and cost, and comprehensively improving the performance and practicality of the axial flow fan. Description of the Drawings

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0019] Figure 1 Is a three-dimensional structure diagram of the present invention; Figure 2 Is a three-dimensional structure diagram of the impeller of the present invention; Figure 3 Is a connection structure diagram of the hub and the blade of the present invention; Figure 4 Is a schematic structural diagram of the installation groove of the present invention; Figure 5 Is a schematic structural diagram of the blade root of the present invention; Figure 6 Is a schematic locking structure diagram of the present invention; Figure 7 Is a partial sectional view of the locking structure of the present invention; Figure 8 Is a schematic structural diagram of the weight combination of the present invention.

[0020] Explanation of the reference numerals in the drawings: 1. Housing; 2. Motor; 3. Impeller; 31. Hub; 32. Blade; 33. Installation groove; 331. Contact interface; 34. Connection root; 341. Insertion section; 342. Fastening section; 4. Positioning structure; 41. Positioning groove; 42. Insertion port; 43. Positioning rib; 44. Locking bar; 45. Locking groove; 5. Locking structure; 50. Rubber layer; 51. Fixed bottom plate; 52. Fixed ring; 53. Locking ring cover; 54. Support part; 55. Snap ring groove; 56. Upper contact surface; 57. Lower contact surface; 58. Pressing surface; 59. Compensation gap; 6. Inner cavity; 7. Weight combination; 71. Slide rail; 72. Counterweight; 8. Dynamic balance test component; 9. Piezoelectric vibration sensor.

[0021] The realization of the object, functional features and advantages of the present invention will be further described with reference to the embodiments and the drawings. Detailed implementation manners

[0022] In order to make the purpose, technical solutions and advantages of the present application more clear, the following will further describe the present application in detail with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0023] As Figure 1-8As shown in the figure, the present invention provides an axial flow fan, which includes a housing 1, a motor 2 and an impeller 3. The impeller 3 is driven to rotate by the output shaft of the motor 2.

[0024] Among them, the impeller 3 is a key component of the axial flow fan, which can play a guiding role for air; the impeller 3 mainly includes a hub 31 connected to the motor 2 and blades 32 arranged on the periphery of the hub 31. At present, the existing blades 32 are mainly fixed on the periphery of the hub 31 by welding. The welding fixation method between the blades 32 and the hub 31 will cause the following problems: First, when one of the blades 32 is damaged or worn, the entire impeller 3 needs to be disassembled and replaced. While the maintenance is more troublesome, replacing the whole impeller 3 also increases the maintenance cost; at the same time, for some large axial flow fans, the overall transportation and installation difficulty will be greater; the blades 32 will greatly increase the diameter size of the impeller 3, so during transportation, it will occupy a large space, resulting in the inability to transport too many impellers 3 at a time, which increases the transportation cost.

[0025] Currently, there are also structures with detachable blades 32 on the market to replace the welding method. However, since the blades 32 and the hub 31 adopt a detachable structure, it will affect the installation angle and position of the blades 32 during installation. At the same time, because the quality of each blade 32 will have a certain difference, ultimately the impeller 3 installed on site will have poor dynamic balance performance, resulting in vibration and noise during the rotation of the impeller 3, which will affect the service life of the equipment and also the connection strength between the blades 32 and the hub 31.

[0026] And as Figure 1-5 shown, in the present application, by providing a positioning structure 4 and a locking structure 5 between the blades 32 and the hub 31, the accuracy of the angle and position of the blades 32 and the hub 31 during on-site installation can be improved, thereby ensuring the dynamic balance performance of the impeller 3 during the installation process.

[0027] Among them, as Figure 2-3 shown, the hub 31, as the core structure, is provided with a number of equally spaced installation grooves 33 on its periphery for installing a plurality of blades 32. The connecting root 34 of each blade 32 is matched with the installation groove 33 on the hub 31 by plugging, forming a detachable connection, thus replacing the traditional welding structure and significantly reducing the maintenance complexity and cost caused by blade 32 wear.

[0028] Specifically, the installation groove 33 is cylindrically arranged, and an abutting interface 331 is provided at one end thereof close to the blade 32; the connecting root 34 includes a plugging section 341 inserted into the installation groove 33, and a fastening section 342 that abuts against the abutting interface 331 is provided at one end of the plugging section 341 away from the hub 31; the abutting interface 331 is conically arranged, and its inner diameter gradually increases outward along the bottom of the installation groove 33; the outer diameter of the fastening section 342 gradually increases outward along the bottom of the installation groove 33 to fit with the inner wall of the abutting interface 331. When the connecting root 34 of the blade 32 is inserted into the installation groove 33, the cooperation between the fastening section 342 and the abutting interface 331 can provide a certain fastening force in the radial direction, so that the blade 32 has a certain stability during initial installation, preventing the blade 32 from radially shaking in the installation groove 33; thereby ensuring the connection stability between the blade 32 and the hub 31, and avoiding the existence of a gap between the connecting root 34 and the installation groove 33, which may cause the blade 32 to shake during the rotation of the impeller 3, thus affecting the normal operation of the impeller 3.

[0029] For the positioning structure 4, its main purpose is to ensure that the installation angle and position between the blade 32 and the hub 31 are consistent with those of the impeller 3 at the time of leaving the factory; since before the impeller 3 is shipped, the dynamic balance performance of the impeller 3 will be adjusted through the dynamic balance test equipment in the factory, so that the installation angle of the blade 32 and the counterweight 72 are both adjusted to the optimal position, and through the positioning structure 4, when the blade 32 is reassembled on site, the angle between the blade 32 and the hub 31 can be exactly the same as the angle at the time of leaving the factory, thereby ensuring the dynamic balance performance of the impeller 3.

[0030] Specifically, as Figure 3-5 shown, the positioning structure 4 includes a plurality of positioning grooves 41 on the inner wall of the installation groove 33. The positioning grooves 41 extend along the axial direction of the installation groove 33, and an insertion port 42 is provided at one end thereof facing the abutting interface 331. The plurality of positioning grooves 41 are equidistantly distributed on the inner wall of the installation groove 33; it also includes at least one positioning rib 43 provided on the outer side wall of the plugging section 341, and the positioning rib 43 is inserted and matched with any one of the positioning grooves 41.

[0031] The cross-section of the positioning groove 41 is T-shaped, and it also includes a plurality of locking bars 44 that are inserted into the positioning groove 41 and are detachably arranged relative to the positioning groove 41. The number of the locking bars 44 is less than the number of the positioning grooves 41, and one side thereof protrudes outward from the positioning groove 41; a plurality of locking grooves 45 that are engaged with the locking bars 44 are also provided on the circumferential side of the plugging section 341, and the plurality of locking grooves 45 and the positioning ribs 43 form a limiting structure corresponding to the number and position of the positioning grooves 41.

[0032] Among them, the positioning groove 41 provided in the installation groove 33 can be inserted and matched with the positioning rib 43 provided on the circumferential side of the insertion section 341, so as to realize the locking and limiting of the axial position of the blade 32. A locking strip 44 that is detachable relative to the positioning groove 41 is inserted into the positioning groove 41. The number of locking strips 44 is less than the number of positioning grooves 41 and one side protrudes outward from the positioning groove 41. A locking groove 45 that is engaged with the locking strip 44 is provided on the circumferential side of the insertion section 341. The locking groove 45 and the positioning rib 43 form a limiting structure corresponding to the number and position of the positioning grooves 41. The setting of the above structure enables the staff to ensure that the position between the blade 32 and the hub 31 is the same as the angular position at the time of leaving the factory when installing the blade 32 and the hub 31, and to ensure that the angles between all the blades 32 and the hub 31 are the same when several blades 32 are installed, thereby improving the dynamic balance performance of the impeller 3 during operation. Specifically, since the number of locking strips 44 is less than the number of positioning grooves 41, at least one positioning groove 41 will be in an empty state after the locking strip 44 is inserted into the positioning groove 41. In this embodiment, the number of locking strips 44 is only one less than the number of positioning grooves 41. At the same time, since the positioning rib 43 is fixedly provided on the circumferential side of the connecting root 34, the positioning rib 43 will correspond to the position of the only positioning groove 41, so that there is only one installation position angle between the blade 32 and the installation groove 33, and this installation angle can be the best angle calibrated by the factory during the dynamic balance debugging of the impeller 3. Therefore, when the blade 32 is reinstalled on site, the installation angle between the blade 32 and the hub 31 can be made exactly the same as that in the factory state, which can avoid affecting the dynamic balance of the impeller 3 due to the change of the installation angle between the blade 32 and the hub 31 during the installation process of the blade 32.

[0033] At the same time, by adjusting the position of the locking strip 44, different angles of the positioning grooves 41 can be made in an empty state, thereby facilitating the adjustment of the angle of the blade 32. The locking groove 45 provided in the connecting root 34 can be inserted into the position of the locking strip 44, thereby improving the connection strength and stability between the insertion section 341 at the root of the blade 32 and the installation groove 33. If you want to further reduce the difference in dynamic balance between when the impeller 3 leaves the factory and after on-site installation, the blade 32 can correspond to the installation groove 33 one by one, so as to ensure that the quality of the blade 32 at each position of the hub 31 is the same as that during the factory debugging process, thereby ensuring the dynamic balance performance of the impeller 3.

[0034] Such as Figure 6-7, Further, a locking structure 5 is also provided between the root of the blade 32 and the hub 31. The locking structure 5 includes a fixed bottom plate 51 disposed on the hub 31 and located at the opening of the mounting groove 33, and a fixed ring 52 disposed on the periphery of the connecting root 34. A locking ring cover 53 is provided between the fixed bottom plate 51 and the fixed ring 52, and the locking ring cover 53 is fixedly connected to the fixed bottom plate 51 by bolts.

[0035] A cylindrical support portion 54 is provided between the fixed bottom plate 51 and the hub 31, and the support portion 54 forms a gap between the fixed bottom plate 51 and the hub 31; the locking ring cover 53 includes a left ring cover and a right ring cover which are separately arranged. Clamping ring grooves 55 are provided on the peripheries of the left ring cover and the right ring cover. The clamping ring grooves 55 are open on one side facing the fixed bottom plate 51, and upper abutting surfaces 56 and lower abutting surfaces 57 are formed on the inner walls thereof. The upper abutting surface 56 abuts against the upper surface of the fixed ring 52, and the lower abutting surface 57 abuts against the lower surface of the fixed bottom plate 51.

[0036] The upper abutting surface 56 is provided with a downward pressing surface 58 which is tapered in the direction of the clamping ring groove 55. The downward pressing surface 58 is used to drive the fixed ring 52 to move towards the fixed bottom plate 51 when contacting the fixed ring 52.

[0037] A compensation gap 59 exists between the fixed bottom plate 51 and the fixed ring 52. A rubber layer 50 which is located between the upper abutting surface 56 and the lower abutting surface 57 and corresponds to the position of the compensation gap 59 is provided on the inner wall of the clamping ring groove 55. The thickness of the rubber layer 50 is greater than the height of the compensation gap 59.

[0038] Specifically, it is composed of parts such as the fixed bottom plate 51, the fixed ring 52, the locking ring cover 53, the support portion 54 and the rubber layer 50. The fixed bottom plate 51 is disposed on the hub 31 and located at the opening of the mounting groove 33. It is like a stable base, providing basic support for the entire locking structure 5. The fixed ring 52 surrounds the periphery of the connecting root 34, and the fixed ring 52 and the fixed bottom plate 51 cooperate together to fix the blade 32.

[0039] The locking ring cover 53 plays an important role in the fastening connection. It is composed of a left ring cover and a right ring cover which are separately arranged. This split design facilitates the operation during the installation and disassembly of the blade 32. Clamping ring grooves 55 are provided on the peripheries of the left ring cover and the right ring cover. The clamping ring grooves 55 are open on one side facing the fixed bottom plate 51. The upper abutting surface 56 formed on the inner wall thereof tightly abuts against the upper surface of the fixed ring 52, and the lower abutting surface 57 stably contacts the lower abutting surface 57 of the fixed bottom plate 51. By this way of upper and lower abutting, the fixed ring 52 and the fixed bottom plate 51 are tightly connected together, thereby firmly fixing the blade 32 on the hub 31.

[0040] Between the fixed base plate 51 and the hub 31, a cylindrical support portion 54 is specifically provided. This design creates a gap between the fixed base plate 51 and the hub 31, which is not redundant but has important significance. It provides a certain adjustment space for the locking ring cover 53 during the fastening process, enabling the entire locking structure 5 to better adapt to different installation conditions and working stresses.

[0041] The upper abutting surface 56 is provided with a conical downward pressing surface 58 facing the clamping ring groove 55. When the locking ring cover 53 is fixedly connected to the fixed base plate 51 through bolts, as the bolts are tightened, the locking ring cover 53 gradually tightens, and the conical downward pressing surface 58 of the upper abutting surface 56 will contact the fixed ring 52. Since the downward pressing surface 58 is conical, a component force along the cone surface will be generated during contact, and this component force will drive the fixed ring 52 to move towards the fixed base plate 51, thereby further enhancing the connection tightness between the fixed ring 52 and the fixed base plate 51, and thus more firmly fixing the blade 32, effectively preventing the blade 32 from loosening during the high-speed operation of the fan.

[0042] In addition, considering that in the actual production and assembly process, there may be certain dimensional tolerances for each component. To compensate for the connection instability that may be brought about by these tolerances, a compensation gap 59 is specifically reserved between the fixed base plate 51 and the fixed ring 52. At the same time, a rubber layer 50 is provided at a position on the inner wall of the clamping ring groove 55 corresponding to the compensation gap 59 between the upper abutting surface 56 and the lower abutting surface 57. The rubber layer 50 has good elasticity, and its thickness is specifically designed to be greater than the height of the compensation gap 59. When the locking ring cover 53 tightens and the fixed ring 52 is driven by the downward pressing surface 58 to move towards the fixed base plate 51, the rubber layer 50 will be squeezed and elastically deformed to fill the compensation gap 59, further enhancing the connection stability, ensuring that the connection between the blade 32 and the hub 31 can withstand various forces generated during the operation of the fan, and guaranteeing the stable and reliable operation of the axial flow fan. The entire locking structure 5 realizes a firm and reliable connection between the blade 32 and the hub 31 through the coordinated work of each part, meeting the requirements of the axial flow fan for stable operation under different working conditions.

[0043] Furthermore, as Figure 1 、 8 shown, an inner cavity 6 with an opening is provided in the hub 31. A plurality of slide rails 71 corresponding to the impeller 3 are provided in the inner cavity 6. A plurality of weight groups 7 are slidably arranged on the slide rails 71. The plurality of weight groups 7 are circumferentially distributed in the inner cavity 6 and can move linearly from the edge of the inner cavity 6 towards the center of the inner cavity 6; among them, the weight group 7 includes a weight block 72 slidably arranged on the slide rail 71. A fastening bolt is threadedly connected to the weight block 72, and the end of the fastening bolt can pass through the weight block 72 and press tightly against the surface of the slider, thereby realizing the position fixation of the weight block 72.

[0044] When the impeller 3 is in the factory commissioning stage, during the dynamic balance test of the impeller 3 by the staff, by adjusting the position of the counterweight 72, the dynamic balance of the impeller 3 can be made within the required range. In this way, after the transportation of the impeller 3 is completed and during the on-site installation, only the corresponding blade 32 needs to be inserted into the corresponding installation groove 33 and the installation angle between the blade 32 and the hub 31 is ensured to be exactly the same as that at the factory by the positioning component. At this time, since the counterweight 72 is in a debugged state, after installation, it can be ensured as much as possible that the dynamic balance of the impeller 3 does not differ much from the factory state, thus avoiding some variables in on-site installation, such as the installation position and angle of the blade 32, from affecting the dynamic balance of the impeller 3.

[0045] On this basis, as Figure 1 shown, in order to more conveniently detect the dynamic balance of the impeller 3 installed on site, a dynamic balance test component 8 is further provided on the housing 1. Among them, the principle of the dynamic balance test component 8 is prior art. Specifically, the dynamic balance test component 8 includes a plurality of piezoelectric vibration sensors 9 arranged on the inner wall of the housing 1 and opposite to the impeller 3. The piezoelectric vibration sensors 9 are connected to the data terminal through the main control module, convert the vibration generated by the housing 1 into vibration signals, process them, and then send them to the data terminal.

[0046] Specifically, the sensors are all arranged on the inner wall of the housing 1, and their arrangement positions are opposite to the position of the impeller 3 to ensure that the vibration response caused by the rotation of the impeller 3 can be accurately captured. The piezoelectric vibration sensor 9 is an electronic device designed based on the piezoelectric effect principle. When subjected to mechanical vibration, the internal piezoelectric material of it will undergo a small deformation, and then charge accumulation will occur between the two poles, forming a voltage signal that can be read by the subsequent circuit. By continuously sampling these voltage signals, the vibration amplitude, frequency and change trend of the housing 1 under different operating states can be restored.

[0047] These sensors are connected to the main control module by wired or wireless means. As the core of signal processing and logic control, the main control module is not only limited to receiving the original vibration electrical signals uploaded by the sensors, but also includes operations such as signal preprocessing, filtering, time-domain and frequency-domain analysis, so as to extract key characteristic values reflecting the dynamic balance state of the impeller 3, such as vibration acceleration amplitude, main frequency component, phase difference, etc. This module is embedded with a microprocessor and can execute existing algorithms such as fast Fourier transform, convert the time series signal into frequency-domain information, and then determine whether the current vibration is within the allowable range or there is a risk of exceeding the standard.

[0048] The processed signal and analysis results will be transmitted to the data terminal in real time. The data terminal can be a portable tablet, a computer, or a display device in the fan control room. Through the data terminal interface, users can intuitively view the vibration condition of the current fan, and the system can also issue a warning message according to the set threshold. If abnormal counterweight on one side is detected or significant eccentricity occurs during rotation, maintenance personnel can, based on the analysis results provided by the data terminal, adjust the position of the counterweight assembly 7 inside the hub 31 in a targeted manner to complete the dynamic balance correction operation. This enables users to conveniently perform real-time debugging of the dynamic balance of the impeller 3 after on-site installation, avoiding the influence of the detachable blade 32 structure on the dynamic balance of the impeller 3.

[0049] Through the above dynamic balance test assembly 8, the assembly can achieve real-time dynamic balance detection of the impeller 3 under actual working conditions, avoiding the cumbersome process of disassembling the impeller 3 and sending it to a dedicated testing device for testing in the traditional method, thus greatly saving the testing time and labor costs. Secondly, by utilizing the high-sensitivity characteristic of the piezoelectric vibration sensor 9, the system can accurately capture the tiny vibration signals caused by uneven counterweight or assembly error, and cooperate with the main control module to perform frequency-domain analysis and trend judgment on the vibration signals, enabling dynamic balance problems to be detected at an early stage and effectively reducing potential hazards such as long-term fatigue damage, increased noise, or structural looseness caused by unbalanced operation of the equipment.

[0050] In addition, through the visual vibration analysis results provided by the data terminal, maintenance personnel can quickly locate the problem counterweight position and timely adjust the balance state of the impeller 3 in combination with the adjustable counterweight assembly 7 structure. The entire debugging process is simple and fast, further reducing the technical threshold and operation risk.

[0051] In the drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components; in the description of this application, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only for illustrative purposes and cannot be construed as a limitation of this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0052] The above is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of this application shall be included within the protection scope of this application.

Claims

1. An axial flow fan, comprising a casing (1), a motor (2) and an impeller (3), characterized in that: The impeller (3) comprises: A wheel hub (31) drivingly connected to an output shaft of the motor (2); a plurality of mounting grooves (33) distributed at equal distances are arranged on the circumference of the wheel hub (31); A plurality of blades (32), the number of positions of the plurality of blades (32) corresponding to the number of positions of the mounting grooves (33), the blades (32) comprising a connecting root (34) plug-fitting with the mounting grooves (33), the connecting root (34) plug-fitting with the mounting grooves (33); A positioning structure (4), arranged between the connecting root (34) and the inner wall of the mounting groove (33), and used to lock the mounting angle between the blade (32) and the hub (31); The locking structure (5) is arranged between the connecting root (34) and the wheel hub (31) and is used to fix the blade (32) to the wheel hub (31) through the root of the blade (32), and the locking structure (5) can release the fixation between the root of the blade (32) and the wheel hub (31) to achieve the removal of the blade (32).

2. An axial flow fan according to claim 1, characterized in that: The mounting groove (33) is cylindrical, and an abutment interface (331) is provided at one end thereof close to the blade (32); the connecting root (34) comprises an inserting section (341) inserted into the mounting groove (33), and an end of the inserting section (341) away from the hub (31) is provided with a fastening section (342) that abuts against the abutment interface (331); the abutment interface (331) is conical, and its inner diameter gradually increases outwardly along the bottom of the mounting groove (33); the outer diameter of the fastening section (342) gradually increases outwardly along the bottom of the mounting groove (33) to fit with the inner wall of the abutment interface (331).

3. An axial flow fan according to claim 2, characterized in that: The positioning structure (4) comprises a plurality of positioning grooves (41) on the inner wall of the mounting groove (33), wherein the positioning groove (41) extends axially along the mounting groove (33) and an insertion opening (42) is provided at one end thereof facing the abutment interface (331), and the plurality of positioning grooves (41) are distributed at equal distances on the inner wall of the mounting groove (33); and further comprises at least one positioning convex strip (43) provided on the outer wall of the plug-in section (341), wherein the positioning convex strip (43) is pluggably engaged with any of the positioning grooves (41).

4. An axial flow fan according to claim 3, characterized in that: The positioning groove (41) has a T-shaped cross section and further comprises a plurality of locking strips (44) inserted into the positioning groove (41) and detachably arranged relative to the positioning groove (41), wherein the number of the locking strips (44) is less than the number of the positioning grooves (41) and one side of the locking strips (44) protrudes outward from the positioning groove (41); a plurality of locking grooves (45) engaging with the locking strips (44) are also arranged around the plug-in section (341), wherein the plurality of locking grooves (45) and the positioning protruding strips (43) form a limiting structure corresponding to the number and position of the positioning grooves (41).

5. An axial flow fan according to any one of claims 1 to 4, characterized in that: The locking structure (5) comprises a fixed base plate (51) arranged on the wheel hub (31) and located at the opening of the mounting groove (33), and a fixed ring (52) arranged on the peripheral side of the connecting root (34), a locking ring cover (53) being arranged between the fixed base plate (51) and the fixed ring (52), and the locking ring cover (53) and the fixed base plate (51) being fixedly connected by bolts.

6. An axial flow fan according to claim 5, characterized in that: A cylindrical support portion (54) is provided between the fixed base plate (51) and the wheel hub (31), and the support portion (54) forms a gap between the fixed base plate (51) and the wheel hub (31); the locking ring cover (53) comprises a left ring cover and a right ring cover which are separately provided, and a snap ring groove (55) is provided on the circumference of the left ring cover and the right ring cover, and the snap ring groove (55) is open toward one side of the fixed base plate (51) and has an upper abutting surface (56) and a lower abutting surface (57) formed on its inner wall, the upper abutting surface (56) abuts against the upper surface of the fixed ring (52), and the lower abutting surface (57) abuts against the lower surface of the fixed base plate (51).

7. An axial flow fan according to claim 6, characterized in that: The upper abutment surface (56) is provided with a conical downward pressing surface (58) facing the clamping ring groove (55); the downward pressing surface (58) is used to drive the fixing ring (52) to move towards the fixing base plate (51) when in contact with the fixing ring (52).

8. An axial flow fan according to claim 7, characterized in that: A compensation gap (59) exists between the fixed bottom plate (51) and the fixed ring (52); the inner wall of the snap ring groove (55) is provided with a rubber layer (50) located between the upper abutment surface (56) and the lower abutment surface (57) and corresponding to the position of the compensation gap (59); the thickness of the rubber layer (50) is greater than the height of the compensation gap (59).

9. The axial flow fan according to claim 1, characterized in that: The wheel hub (31) is provided with an inner cavity (6), and a plurality of weight groups (7) are slidably provided in the inner cavity (6), and the plurality of weight groups (7) are circumferentially distributed in the inner cavity (6) and can move linearly along the edge of the inner cavity (6) toward the center of the inner cavity (6); and further comprises a dynamic balancing test assembly (8) provided on the casing (1), the dynamic balancing test assembly (8) comprising a plurality of piezoelectric vibration sensors (9) provided on the inner wall of the casing (1) and arranged relative to the impeller (3), the piezoelectric vibration sensor (9) being connected to a data terminal via a main control module, converting vibration generated by the casing (1) into a vibration signal, processing the signal, and then transmitting the signal to the data terminal.

10. An axial flow fan according to claim 8, characterized in that: The left ring cover and the right ring cover are both semi-ring-shaped, and horizontally arranged connecting plates are arranged at opposite ends of the two, and the connecting plates are fixedly connected by bolts.

Images