A variable air duct structure and a fan with a variable air duct structure

Abstract

This invention relates to a variable air duct structure and a fan having the same structure. The variable air duct structure includes: an annular rotating frame; multiple guide vanes spaced circumferentially along the rotating frame; a gear at one end of each guide vane meshing with a meshing structure of the rotating frame; a guide vane shaft connected to the gear of one of the guide vanes; and a stepper motor driving the active guide vane to oscillate via the guide vane shaft, which in turn drives the driven guide vane to oscillate synchronously via the rotating frame, thereby changing the airflow direction or pattern of the variable air duct structure. The invention achieves continuous and smooth changes in airflow pattern and airflow output direction through the synchronous oscillation of the guide vanes, enabling rapid switching to achieve various airflow effects such as wide-area gentle airflow, localized concentrated strong airflow, and multi-angle circulating airflow, comprehensively meeting the airflow needs of different scenarios. Only a single guide vane needs to be driven to drive all vanes to oscillate synchronously, with no lag, misalignment, or jamming in the vane movement.

Description

Technical Field

[0001] This invention relates to the field of fan technology, specifically to a variable airflow structure and a fan having a variable airflow structure. Background Technology

[0002] Fans, as common household appliances for ventilation and heat dissipation, are widely used in homes, offices, and other scenarios. Most existing fan products adopt a fixed air duct structure, resulting in a single airflow output direction and a fixed air delivery coverage area. They can only achieve basic air delivery functions, such as the common mechanical oscillation function, which can only achieve wide-range oscillation air delivery. They cannot switch to diverse air delivery effects such as wide-area gentle air delivery, localized concentrated strong wind, or multi-angle circulating air delivery according to the needs of the usage scenario, making it difficult to meet users' needs for different air delivery modes.

[0003] Some fan products that attempt to achieve wind direction and air volume adjustment, such as structures where multiple drive components control different air guide parts, can achieve diverse wind directions. However, configuring an independent drive structure for each air guide part results in a large number of parts, complex assembly processes, and a bulky overall layout. At the same time, too many mechanical structures and transmission nodes significantly increase the probability of equipment failure, leading to short product lifespan and high maintenance costs.

[0004] The above problems are worth solving. Summary of the Invention

[0005] In order to overcome the problems of existing fans having fixed air ducts resulting in a single air outlet mode and numerous components and high failure probability in multi-drive air guide structures, this invention provides a variable air duct structure and a fan with a variable air duct structure.

[0006] The technical solution of this invention is as follows: A variable air duct structure, comprising: The rotating frame, in a ring shape, is positioned in the direction of the fan's airflow. Multiple air guide blades are arranged at intervals along the circumference of the rotating frame. Each air guide blade has a gear at one end, and the gear meshes with a meshing structure provided on the rotating frame. The drive assembly includes a stepper motor and a guide vane shaft, the guide vane shaft being gear-driven connected to one of the guide vanes; The stepper motor drives the guide vanes connected to the guide vane shaft to swing through the guide vane shaft, and then drives all other guide vanes to swing synchronously through the rotating frame, so as to change the air outlet direction or air outlet pattern of the variable air duct structure.

[0007] As a preferred embodiment of the present invention, the meshing structure is a plurality of toothed racks disposed on the inner side of the rotating frame, wherein the gears mesh with the toothed racks in a one-to-one correspondence.

[0008] As a preferred embodiment of the present invention, the drive assembly further includes a torque limiter connected between the output shaft of the stepper motor and the guide vane shaft.

[0009] Furthermore, the torque limiter includes a limiter body, a limiter top cover, and a limiter bottom cover; the limiter top cover is inserted into the shaft hole of the limiter body; the top surface of the limiter body is provided with a slot, the limiter top cover is provided with a limiting block that cooperates with the slot, the center of the limiter top cover is provided with a D-shaped hole, and one end of the guide vane shaft is inserted into the D-shaped hole to achieve a transmission connection.

[0010] Furthermore, the bottom surface of the torque limiter is provided with two plug-in blocks, the center of the limiter bottom cover is provided with a through hole, and two plug-in holes corresponding to the plug-in blocks are provided on both sides of the through hole. The output shaft of the stepper motor is inserted into the through hole, and the plug-in blocks of the torque limiter are connected to the plug-in holes of the limiter bottom cover, thereby realizing the connection between the limiter bottom cover and the limiter body.

[0011] Furthermore, the slot is a straight slot, the limiting block is a straight limiting block, and the through hole is an elongated hole or a racetrack-shaped hole.

[0012] As a preferred embodiment of the present invention, it further includes an annular louvered bottom shell, the annular edge of which is provided with an annular groove, and the rotating frame is rotatably assembled in the annular groove; the louvered bottom shell is uniformly provided with a plurality of stroke limiting grooves along the inner side of the annular groove, and the meshing structure of the rotating frame is placed in the stroke limiting groove to limit the rotation angle range of the rotating frame.

[0013] Furthermore, it also includes a circular louvered top shell, with the rotating frame and multiple air guide blades encapsulated between the louvered top shell and the louvered bottom shell.

[0014] Furthermore, the top and bottom shells of the louvers are provided with a plurality of pivoting mounting holes; each of the guide vanes has an integrally protruding upper pivoting shaft head at the top and a integrally protruding lower pivoting shaft head at the bottom; the upper pivoting shaft head is inserted into the corresponding pivoting mounting hole of the top shell of the louvers, and the lower pivoting shaft head is inserted into the corresponding pivoting mounting hole of the bottom shell of the louvers, so that the gear can rotate freely around its own pivoting shaft head.

[0015] As a preferred embodiment of the present invention, the guide vane is an arc-shaped blade, and the length direction of the guide vane from one end of the gear to the free end is defined as the length direction, while the width direction of the guide vane is perpendicular to the length direction; the guide vane is curved in an arc shape in the length direction; the blade surface of the guide vane includes a first half-blade close to the fan blade and a second half-blade away from the fan blade in the width direction, the blade surface of the first half-blade is in the direction of airflow, and the blade surface of the second half-blade is curved to one side.

[0016] The present invention also provides a fan with a variable air duct structure, comprising: The fan head assembly includes a rear grille housing, a head bracket, and a front grille housing. The rear grille housing and the front grille housing are respectively connected to the rear and front sides of the head bracket, and together they form the outer shell of the fan head. A base assembly, connected to the fan head assembly, is used to support the fan head assembly; And a variable air duct structure as described above, wherein the variable air duct structure is disposed within the head support and located behind the front mesh housing.

[0017] As a preferred embodiment of the present invention, the head support includes a circular frame at the front end and a crossbar at the rear end. The circular frame is used to accommodate the variable air duct structure, and the crossbar is used to install the fan blade motor.

[0018] As a preferred embodiment of the present invention, the fan head assembly further includes a fan blade motor and a fan blade. The fan blade motor is fixed on the crossbar of the head bracket, the fan blade is connected to the output shaft of the fan blade motor, and the fan blade is located within the circular frame of the head bracket and behind the variable air duct structure.

[0019] As a preferred embodiment of the present invention, the base assembly includes a base and two connecting arms, the lower ends of the two connecting arms are connected to the base, and the upper ends of the two connecting arms are respectively hinged to the left and right sides of the head support.

[0020] Furthermore, the base assembly also includes a first drive motor, which is mounted on the connecting arm or the head bracket and is used to drive the head bracket to swing up and down relative to the connecting arm.

[0021] Furthermore, the base includes an upper base, a lower base, and a second drive motor. The upper base is rotatably mounted on the lower base. The second drive motor is installed inside the base and is used to drive the upper base to rotate horizontally relative to the lower base.

[0022] According to the above-described solution, the beneficial effects of this invention are as follows: This invention enables the continuous and smooth change of airflow pattern and airflow output direction through the synchronous oscillation of the guide vanes. It can quickly switch between various air outlet effects such as wide-area gentle air supply, local concentrated strong wind, and multi-angle circulating air sweeping, fully meeting the air supply needs in different scenarios. In this invention, multiple guide vanes are linked and driven by a gear and rotating frame meshing structure. Only a single guide vane needs to be driven to drive all the vanes to swing synchronously. The vane movement is smooth, without lag, misalignment, or jamming. Compared with multiple drive structures or direct overlap of guide vanes, this invention significantly improves the consistency and operational stability of the air guiding action. With the help of a stepper motor, the swing angle, swing speed, and start / stop position of the guide vanes can be precisely controlled, enabling fine and quantitative adjustment of the air outlet direction and air outlet pattern. Moreover, the present invention adopts a minimalist structure of single drive and meshing linkage, which eliminates the need for an independent drive component for each air guide blade. The number of parts is small and the assembly difficulty is low, which simplifies the overall layout of the variable air duct structure, effectively reduces mechanical failure points, and improves structural durability and service life. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the variable air duct structure of the present invention.

[0024] Figure 2 This is a schematic diagram of the guide vanes of a variable air duct structure in the open and deployed state.

[0025] Figure 3 This is an exploded view of the variable air duct structure.

[0026] Figure 4 This is a schematic diagram of the assembly of the air guide vanes and the rotating frame.

[0027] Figure 5 This is an exploded view of the drive component structure of the variable air duct structure.

[0028] Figure 6 This is a schematic diagram of the assembly of the guide vanes and rotating frame on the louvered bottom shell in a variable air duct structure.

[0029] Figure 7 This is a schematic diagram of the fan structure of the present invention.

[0030] Figure 8 This is an exploded view of the fan's structure.

[0031] In the diagram, 1 represents the rotating frame; 11 represents the toothed rack. 2. Guide vane; 21. Gear; 210. Pivot shaft head; 22. First half-blade; 23. Second half-blade; 3. Stepper motor; 31. Guide vane shaft; 4. Torque limiter; 401. Slot; 402. Connecting block; 41. Limiter top cover; 411. Limiting block; 42. Limiter bottom cover; 421. Through hole; 422. Connecting hole; 5. Louvered bottom shell; 51. Circular groove; 52. Stroke limit groove; 53. Pivot assembly hole; 6. Louvered top shell; 7. Fan head assembly; 71. Rear grille housing; 72. Head bracket; 73. Front grille housing; 74. Fan blade motor; 75. Fan blade; 8. Base assembly; 81. Base; 82. Connecting arm. Detailed Implementation

[0032] To better understand the purpose, technical solution, and technical effects of this invention, the invention will be further explained and described below in conjunction with the accompanying drawings and embodiments. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. It is also stated that the embodiments described below are only for explaining this invention and are not intended to limit this invention.

[0033] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intermediate component. When a component is referred to as "connected to" another component, it can be directly connected to the other component or there may be an intermediate component.

[0034] The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product is usually placed when in use, or the orientation or positional relationship in which a person skilled in the art would normally understand it, or the orientation or positional relationship in which the product is usually placed when in use. It is only for the purpose of facilitating the description of this application and simplifying the description, and is 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, and therefore should not be construed as a limitation of this application.

[0035] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or specifying the number of technical features. "A plurality of" means two or more, unless otherwise expressly and specifically defined.

[0036] like Figures 1 to 3As shown, in order to overcome the problems of fixed air ducts in existing fans resulting in a single air outlet mode and numerous components and high failure probability in multi-drive air guide structures, this invention provides a variable air duct structure, including: a rotating frame 1, which is annular in structure and is set in the air outlet direction of the fan; multiple air guide blades 2, which are arranged at intervals along the circumference of the rotating frame 1, and each air guide blade 2 has a gear 21 at one end, which meshes with a meshing structure set on the rotating frame 1; a drive assembly, including a stepper motor 3 and an air guide shaft 31, which is connected to the gear 21 of one of the air guide blades 2; the stepper motor 3 drives the air guide blade 2 connected to the air guide shaft 31 to swing through the air guide shaft 31, and then drives all the remaining air guide blades 2 to swing synchronously through the rotating frame 1, so as to change the air outlet direction or air outlet pattern of the variable air duct structure.

[0037] The technical principle of this invention lies in constructing a centralized linkage transmission system through the meshing of a rotating frame 1 and a gear 21. Specifically, multiple guide vanes 2 are evenly arranged circumferentially along the rotating frame 1. Each guide vane 2 has a gear 21 at one end, and each gear 21 meshes with the meshing structure (toothed rack 11) on the inner side of the rotating frame 1 one by one, thereby forming an integrated linkage system between the rotating frame 1 and all the guide vanes 2 in motion. The stepper motor 3 serves as the sole power input source, and its rotational motion is transmitted to one of the guide vanes 2 (i.e., the active guide vane) via the guide vane shaft 31. The gear 21 of the active guide vane 2 rolls on the toothed rack 11 on the inner side of the rotating frame 1, generating a tangential thrust that drives the rotating frame 1 to rotate around its own axis. After the rotating frame 1 rotates, the toothed racks 11 on its inner side simultaneously apply driving force to the gears 21 of all the other guide vanes 2, causing all the driven guide vanes 2 to swing synchronously around their respective pivot heads 210. When the rotating frame 1 rotates clockwise, the free ends of all the guide vanes 2 synchronously move towards the center of the ring, forming a converging and gathering airflow state; when the rotating frame 1 rotates counterclockwise, the free ends of all the guide vanes 2 synchronously expand outwards, forming a diffused airflow state. By controlling the rotation direction, rotation angle, and speed of the stepper motor 3, the swing direction, angle, and speed of all the guide vanes 2 can be precisely controlled, thereby achieving refined and continuously adjustable airflow direction and pattern.

[0038] During operation, the control system sends control commands to the stepper motor 3. The output shaft of the stepper motor 3 drives the guide vane shaft 31 to rotate, which in turn drives the active guide vane 2 connected to it to swing around the gear 21. The gear 21 on the active guide vane 2 then rolls on the rack 11 inside the rotating frame 1, pushing the rotating frame 1 to rotate along the annular groove 51. While the rotating frame 1 rotates in the annular groove 51, each rack 11 inside it drives the corresponding gear 21 of the driven guide vane 2 to rotate synchronously, achieving synchronous swinging of all the guide vanes 2. When the rotating frame 1 rotates to the limit position of the travel limit groove 52, the gear rack 11 stops moving due to the constraint of the limit stop. A torque limiter 4 can be added between the output shaft of the stepper motor 3 and the guide vane shaft 31. When the rotating frame 1 rotates to the limit position of the travel limit groove 52, the torque limiter 4 slips, cutting off the transmission of excess torque and protecting the stepper motor 3, the rotating frame 1, and the meshing structure of the gear 21 from overload damage. By setting the number of steps and the direction of rotation of the stepper motor 3, all guide vanes 2 can be driven to any preset angle and precisely maintained at that angle without the need for additional feedback sensors. Alternatively, the guide vanes 2 can be driven to swing back and forth between two limit positions, forming a dynamic direction-changing air supply effect. Thus, according to different combinations of the opening degree and swing speed of the guide vanes 2, flexible switching of various air supply modes such as wide-area gentle air supply, local concentrated strong wind, and multi-angle circulating air sweeping can be achieved.

[0039] Therefore, the present invention can achieve the following through the above technical solution: Firstly, since all the guide vanes 2 are connected into a unified transmission whole through the meshing structure of the rotating frame 1, the driving torque can be uniformly transmitted to each guide vane 2 along the inner circumference of the rotating frame 1. There is no motion lag or angle deviation between the vanes, and the action is highly consistent. This avoids the problem of asynchronous movement of the vanes in the direct overlapping structure or multi-drive structure, and realizes the precise synchronous linkage of multiple guide vanes 2.

[0040] Secondly, thanks to the precise angular displacement control characteristics of the stepper motor 3, the swing angle, speed, and start / stop position of the air guide blade 2 can be precisely set, supporting multiple preset levels and continuous speed adjustment, meeting the refined control needs of air outlet effect in different scenarios, significantly improving product functionality and user experience, and achieving precise, continuous, and quantifiable adjustment of air outlet direction and shape.

[0041] Third, by using a single stepper motor 3 as the drive source, there is no need to configure independent drive components for each guide vane 2. This reduces the number of transmission nodes, simplifies the mechanical structure, and simplifies the assembly process, effectively reducing production costs. The reduction in the number of drive components also significantly reduces the probability of mechanical failure, significantly improves structural durability and product lifespan, and reduces subsequent maintenance costs, achieving an overall minimalist structure with fewer parts and high reliability.

[0042] like Figure 4 As shown, in this embodiment, the meshing structure consists of several racks 11 with teeth arranged on the inner side of the rotating frame 1, with each gear 21 meshing with a corresponding rack 11. Each rack 11 is circumferentially distributed along the inner side of the rotating frame 1, and their number corresponds one-to-one with the guide vanes 2. The gear 21 at the end of each guide vane 2 meshes with the corresponding rack 11, forming a local meshing pair of circular gear 21 + linear rack. When the rotating frame 1 rotates circumferentially, each rack 11 moves synchronously with the rotating frame 1, its teeth actuating the teeth of the corresponding gear 21, driving each driven guide vane 2 to rotate, thereby causing the guide vane 2 to oscillate. Because each rack 11 is evenly distributed inside the rotating frame 1 and maintains continuous meshing contact with the gears 21 of each guide vane 2, there is a precise correspondence between the rotation of the rotating frame 1 and the oscillation angle of each guide vane 2, ensuring that the oscillation angle of all guide vanes 2 is completely consistent at any given time.

[0043] In terms of structural assembly, several gear racks 11 are fixedly installed on the inner side of the rotating frame 1, arranged at equal intervals along the circumference of the rotating frame 1. The gears 21 of the guide vanes 2 are rotatably mounted in the corresponding pivot mounting holes 53 of the louver top shell 6 and the louver bottom shell 5 through an integrally protruding upper pivot head 210 at the top and a integrally protruding lower pivot head 210 at the bottom, respectively. The gears 21 can rotate freely around their own pivot heads 210, and the axial position remains unchanged, thereby ensuring that the meshing distance between the gears 21 and the gear racks 11 is stable and the meshing contact is continuous and reliable. During the driving process, the stepper motor 3 drives the active guide vane 2 to swing, and the gears 21 of the active guide vane 2 push the rotating frame 1 to rotate. All the gear racks 11 inside the rotating frame 1 move synchronously, driving the gears 21 of each driven guide vane 2 that mesh with them to rotate, ultimately realizing the synchronous linkage swing of all the guide vanes 2. The travel limit groove 52 restricts the displacement range of each meshing rack 11, ensuring that the swing stroke of all guide vanes 2 is controlled and reciprocates between two extreme positions. In other optional embodiments, the louvered top shell 6 may not be provided with the travel limit groove 52, but the rotation angle range of the stepper motor 3 is strictly set, allowing it to rotate forward and backward within a certain angle range.

[0044] As can be seen, the meshing pair structure of gear 21 and rack 11 in this embodiment is mature, with high transmission accuracy. The contact stress between the meshing tooth surfaces is uniform, and the transmission process is smooth and shock-free. Even under high-frequency reciprocating oscillation conditions, it can still maintain good transmission consistency, significantly improving the smoothness and reliability of the linkage action of the guide vanes 2. The rack 11 and gear 21 are rigidly meshed, with no backlash accumulation, ensuring a precise proportional correspondence between the rotation of the rotating frame 1 and the oscillation angle of each guide vane 2. This ensures that all guide vanes 2 maintain strict synchronization at any oscillation position, and the air outlet pattern adjustment is precise and repeatable. The rack 11 is set on the inner side of the rotating frame 1 and is integrated into the body of the rotating frame 1. No additional transmission components are required, resulting in a compact overall structure with a small footprint. At the same time, the integrated design of the rack 11 and the rotating frame 1 reduces the number of parts and assembly processes, lowers manufacturing costs, and further reduces the failure points of the transmission system, improving the overall durability and service life of the structure.

[0045] like Figure 5 As shown, in a preferred embodiment, the drive assembly further includes a torque limiter 4, which is connected between the output shaft of the stepper motor 3 and the guide vane shaft 31. The torque limiter 4 includes a limiter body, a limiter top cover 41, and a limiter bottom cover 42. The top surface of the limiter body has a slot 401, and the limiter top cover 41 has a limiting block that mates with the slot 401. The center of the limiter top cover 41 has a D-shaped hole, and one end of the guide vane shaft 31 is inserted into the D-shaped hole for transmission connection. The limiter bottom cover 42 has a through hole 421, the output shaft of the stepper motor 3 is inserted into the through hole 421, and the limiter bottom cover 42 is connected to the limiter body. Optionally, the slot 401 is a slot, the limiting block is a block, and the through hole 421 is an elongated hole or a racetrack-shaped hole.

[0046] In this embodiment, a torque limiter 4 is introduced between the output shaft of the stepper motor 3 and the guide vane shaft 31. Its working principle is a friction overload slippage mechanism. Under normal operating conditions, the limiter body, the limiter top cover 41, and the limiter bottom cover 42 work together to reliably transmit the rotational torque of the stepper motor 3 output shaft to the guide vane shaft 31, thereby driving the guide vane 2 to swing normally. When the transmission system encounters abnormal resistance—for example, the guide vane 2 is rigidly stopped at the end of the stroke limit groove 52 by the toothed rack 11 of the rotating frame 1, or mechanical interference occurs in the system—when the torque transmitted to the torque limiter 4 exceeds a preset threshold, the limiting block of the limiter top cover 41 slips relatively in the slot 401, and the torque limiter 4 slips between the stepper motor 3 output shaft and the guide vane shaft 31, thereby cutting off the continued transmission of excess torque and protecting the downstream transmission structure and the stepper motor 3 from overload damage.

[0047] Specifically, the transmission path of the torque limiter 4 is as follows: stepper motor 3 output shaft → limiter bottom cover 42 → limiter body → limiter top cover 41 → guide vane shaft 31. The interface between the slot 401 and the limiting block is the slippage section of the torque limiter 4. This interface maintains locked transmission within the normal torque range, and slips due to circumferential relative displacement under excess torque, thus achieving torque isolation. In terms of specific structure, the limiter top cover 41 is inserted into the shaft hole of the limiter body, and the limiting block on the top cover is engaged in the slot 401 on the top surface of the limiter body. The two form a circumferential stop fit and jointly bear the transmission of rotational torque. The limiter body is connected to the insertion hole 422 of the limiter bottom cover 42 through the bottom insertion block 402. The output shaft of the stepper motor 3 is inserted into the through hole 421 in the center of the limiter bottom cover 42. The non-circular cross-sectional shape (elongated or racetrack-shaped) of the through hole 421 matches the corresponding cross-sectional shape of the stepper motor 3 output shaft to achieve rotational locking between the two, ensuring that the rotational motion of the stepper motor 3 is reliably transmitted to the torque limiter 4. Optionally, the slot 401 can be designed as a slot and the limiting block can be designed as a block; the through hole can be designed as an elongated hole or a racetrack-shaped hole, which can also form a reliable rotational lock with the flat cross-section or D-shaped cross-section of the stepper motor 3 output shaft. During assembly, the output shaft of the stepper motor 3 is inserted into the elongated or racetrack-shaped through hole in the center of the limiter bottom cover 42. The cross-sectional profile of the output shaft fits against the inner wall of the through hole 421, forming a circumferential lock. The bottom surface of the limiter body is connected to the two insertion holes 422 of the limiter bottom cover 42 through two insertion blocks 402, thereby fixing the limiter bottom cover 42 to the limiter body. The limiter top cover 41 is inserted into the shaft hole of the limiter body, and the straight limit block on the top cover is embedded into the straight slot on the top surface of the limiter body, forming a circumferential transmission fit. One end of the guide vane shaft 31 is inserted into the D-shaped hole in the center of the limiter top cover 41. The plane of the D-shaped hole fits against the D-shaped cross-section of the guide vane shaft 31, thereby achieving a rotational lock between the limiter top cover 41 and the guide vane shaft 31, completing the assembly of the entire transmission link.

[0048] During operation, when the stepper motor 3 is driven normally, it drives the guide vane 2 to swing normally. When the guide vane 2 reaches its stroke limit and the rack 11 abuts against the end wall of the stroke limit groove 52, generating rigid resistance, the torque in the transmission link increases sharply. The circumferential shear force exceeds the design threshold of the torque limiter 4, and the limiter top cover 41 slips circumferentially relative to the limiter body. The guide vane shaft 31 stops rotating, the output shaft of the stepper motor 3 spins freely, and the excess torque cannot continue to be transmitted downward, thus effectively protecting the entire transmission system. At the same time, the control system of the stepper motor 3 detects the signal of abnormally high output torque and immediately sends a reverse command to the stepper motor 3. The stepper motor 3 rotates in the opposite direction, driving the guide vane 2 to swing back away from the resistance direction. The torque limiter 4 returns to normal transmission state, and the system can automatically resume operation without manual intervention.

[0049] As can be seen, the introduction of torque limiter 4 provides hardware-level overload isolation protection for stepper motor 3. It immediately slips when the torque exceeds a preset threshold, cutting off the excess torque from the transmission link, eliminating the risk of damage to stepper motor 3 and downstream transmission structures due to overload, significantly extending the service life of the overall transmission structure, and improving product reliability. The slippage of torque limiter 4 cuts off abnormal torque before it reaches rotating frame 1, preventing excess torque from acting on the meshing structure of rotating frame 1 and gear 21, which could lead to tooth wear, breakage of the meshing structure, or deformation of rotating frame 1, fundamentally eliminating the risk of structural damage. Torque limiter 4 consists of three parts: the limiter body, the limiter top cover 41, and the limiter bottom cover 42. It is small in size and lightweight, integrated between the output shaft of stepper motor 3 and the guide vane shaft 31, without increasing the overall space occupied by the drive components. Assembly and disassembly of the components are convenient, facilitating on-site maintenance and parts replacement. It has a compact structure, is easy to assemble, and is convenient to maintain.

[0050] like Figure 3 and Figure 6 As shown, in one specific embodiment, the variable air duct structure further includes an annular louvered bottom shell 5 and an annular louvered top shell 6. The annular edge of the louvered bottom shell 5 is provided with an annular groove 51, and the rotating frame 1 is rotatably assembled in the annular groove 51. A plurality of stroke limiting grooves 52 are evenly provided on the louvered bottom shell 5 along the inner side of the annular groove 51. The meshing structure of the rotating frame 1 is placed in the stroke limiting grooves 52 to limit the rotation angle range of the rotating frame 1. The rotating frame 1 and the plurality of air guide blades 2 are encapsulated between the louvered top shell 6 and the louvered bottom shell 5. The top louver shell 6 and the bottom louver shell 5 are provided with a plurality of pivot mounting holes 53 respectively; the top of the gear 21 of each guide vane 2 is integrally provided with an upper pivot shaft head 210 and the bottom is integrally provided with a lower pivot shaft head 210; the upper pivot shaft head 210 is inserted into the corresponding pivot mounting hole 53 of the top louver shell 6 and the lower pivot shaft head 210 is inserted into the corresponding pivot mounting hole 53 of the bottom louver shell 5, so that the gear 21 can rotate freely around its own pivot shaft head 210.

[0051] Regarding the support and limiting principle of the rotating frame 1, the annular groove 51 on the circumferential edge of the louvered bottom shell 5 forms radial constraint and axial limitation on the rotating frame 1, so that the rotating frame 1 can only rotate circumferentially within the annular groove 51, and cannot undergo radial offset or axial movement. This ensures that the meshing distance between the rotating frame 1 and each guide vane 2 gear 21 remains stable, and ensures that the transmission accuracy is not affected by external force disturbances during operation. At the same time, the stroke limiting grooves 52 evenly distributed on the inner side of the louvered bottom shell 5 constrain the circumferential displacement range of the meshing structure (toothed rack 11) on the rotating frame 1: the two end walls of the stroke limiting grooves 52 respectively form mechanical stops for the forward and reverse rotation of the rotating frame 1. When the rotating frame 1 rotates to any extreme position, the toothed rack 11 abuts against the corresponding end wall, and the rotating frame 1 cannot continue to rotate. All guide vanes 2 also stop synchronously at the corresponding extreme swing angle. The aforementioned stroke limit groove 52 strictly restricts the swing range of the guide vane 2 within the design-allowed range, preventing the guide vane 2 from exceeding the normal working range due to excessive swing, and preventing the gear 21 from dislodging or interfering with the meshing structure due to excessive displacement.

[0052] Regarding the axial positioning principle of the guide vane 2, the pivot mounting holes 53 corresponding to the louver top shell 6 and louver bottom shell 5 provide rotational positioning positions for the gear 21 of the guide vane 2. Each gear 21 of the guide vane 2 has an integrally protruding upper pivot shaft head 210 at the top and a integrally protruding lower pivot shaft head 210 at the bottom. The upper pivot shaft head 210 is inserted into the corresponding pivot mounting hole 53 of the louver top shell 6, and the lower pivot shaft head 210 is inserted into the corresponding pivot mounting hole 53 of the louver bottom shell 5, allowing the gear 21 to rotate freely around its own pivot shaft head 210. The upper and lower constraints of the pivot shaft head 210 of the gear 21 ensure that the axial center position of each gear 21 of the guide vane 2 remains unchanged during operation, thereby ensuring a stable and continuous meshing relationship between the gear 21 and the inner meshing rack 11 of the rotating frame 1. During transmission, there will be no meshing disengagement or movement deviation due to the axial center offset of the gear 21.

[0053] During assembly, the rotating frame 1 is first embedded into the annular groove 51 on the circumferential edge of the louvered bottom shell 5, allowing the rotating frame 1 to rotate freely within the annular groove 51. Several toothed racks 11 on the inner side of the rotating frame 1 are correspondingly placed into the stroke limiting grooves 52 on the inner side of the louvered bottom shell 5, so that the rotation range of the rotating frame 1 is rigidly constrained by the end walls of the stroke limiting grooves 52. Subsequently, the gear 21 ends of each guide vane 2 are aligned with the corresponding pivot mounting holes 53 on the louvered bottom shell 5, so that the lower pivot shaft head 210 of the gear 21 is coaxially aligned with the pivot mounting hole 53 of the bottom shell, and the gear 21 meshes with the corresponding toothed racks 11 on the inner side of the rotating frame 1. Subsequently, the louvered top shell 6 and the louvered bottom shell 5 are aligned, and the pivot mounting holes 53 on the top shell and the pivot mounting holes 53 on the bottom shell are aligned one by one. The upper pivot shaft head 210 of the gear 21 is inserted into the pivot mounting hole 53 of the louvered top shell 6. The rotating frame 1 and all the air guide blades 2 are encapsulated between the top shell and the bottom shell to form a complete variable air duct structure module, which completes the axial positioning and rotation constraint of each air guide blade 2, so that the gear 21 of each air guide blade 2 can rotate freely around its own pivot shaft head 210.

[0054] During operation, the stepper motor 3 drives the rotating frame 1 to rotate circumferentially within the annular groove 51. The toothed rack 11 on the inner side of the rotating frame 1 moves accordingly within the travel limit groove 52, synchronously actuating the gears 21 of each guide vane 2 to rotate around its own pivot head 210, causing each guide vane 2 to swing. When the toothed rack 11 moves to the end wall of the travel limit groove 52, the rotating frame 1 is mechanically stopped and stops rotating. All guide vanes 2 stop synchronously at their corresponding limit positions. Combined with the slippage protection of the torque limiter 4 and the self-recovery mechanism of the stepper motor 3, the overall operation is safe and controllable.

[0055] like Figure 4 As shown, in a preferred embodiment, the guide vane 2 is an arc-shaped blade. The length direction of the guide vane 2 from one end of the gear 21 to the free end is defined as its length direction, while the width direction of the guide vane 2 is perpendicular to its length direction. The guide vane 2 is curved in an arc shape in its length direction. The blade surface of the guide vane 2 includes a first half-blade 22 near the fan blade and a second half-blade 23 away from the fan blade in its width direction. The blade surface of the first half-blade 22 faces the airflow direction, while the blade surface of the second half-blade 23 is curved to one side. This embodiment features a targeted aerodynamic optimization design for the geometry of the guide vane 2. By introducing arc-shaped bends in both the length and width directions, the guide vane 2 combines airflow rectification and airflow deflection functions, thereby achieving precise shaping of the exhaust airflow without adding any additional guiding components.

[0056] Regarding the arc-shaped curvature along its length, the guide vane 2 extends along an arc from the fixed end to the free end of the gear 21, giving the overall profile of the guide vane 2 an arc-shaped surface. When airflow passes through the guide vane 2 in the outlet direction, the arc-shaped surface can apply a smoother and more continuous guiding force to the airflow compared to a straight blade, reducing flow separation on the blade surface, lowering the intensity of local turbulence, and allowing the airflow to maintain laminar characteristics after passing through the guide vane 2, resulting in lower airflow noise and a softer, more uniform airflow. Simultaneously, when the arc-shaped blade swings to different angles, its arc-shaped profile can form airflow cross-sections of varying shapes with adjacent blades, further enriching the range of airflow shape variations in the variable airflow duct structure.

[0057] Regarding the double-blade design in the width direction, the first half-blade 22 is closer to the fan blade, and its blade surface extends along the airflow direction. It mainly undertakes the initial rectification and reception function of the airflow, smoothly guiding the airflow blown by the fan blade to the blade surface of the guide blade 2. The second half-blade 23 is farther away from the fan blade, and its blade surface is bent to one side, forming a guide surface with a deflection angle relative to the airflow direction. It applies a lateral deflection force to the airflow after it has been rectified by the first half-blade 22, causing the airflow to produce a significant directional deflection when it leaves the free end of the guide blade 2, forming a directional airflow with a lateral component. The above-mentioned composite design of the two blade sections enables a single guide blade 2 to simultaneously possess the complete airflow shaping capabilities of receiving airflow, smoothing rectification, and lateral deflection. When the guide blade 2 swings to different angles, it can output airflow effects with different directions and shapes. It is evident that the double half-blade composite design in the width direction endows the single guide blade 2 with significant airflow deflection capability. The bent blade surface of the second half-blade 23 applies a lateral deflection force to the airflow, enabling the variable air duct structure to achieve a significant airflow direction deflection even when the guide blade 2 only makes a small angle swing. This effectively expands the airflow direction adjustment range of the variable air duct structure and enhances the diversity and controllability of the airflow pattern.

[0058] The geometric design of the arc-shaped guide vane 2 is highly coordinated with the linkage transmission mechanism of the rotating frame 1. When the guide vane 2 swings to different angles, the cross-sectional shape of the air duct formed between the arc-shaped vane and the adjacent vane changes continuously. Combined with the lateral deflection effect of the second half-blade 23, the variable air duct structure can output a continuously adjustable air outlet direction and air outlet shape, realizing a variety of personalized air outlet modes such as wide-area gentle air supply, local concentrated strong wind, and multi-angle circulating air sweeping.

[0059] like Figure 7As shown, the present invention also provides a fan with a variable airflow structure, comprising: a fan head assembly 7, including a rear mesh housing 71, a head support 72, and a front mesh housing 73, wherein the rear mesh housing 71 and the front mesh housing 73 are respectively connected to the rear and front sides of the head support 72, together forming the outer shell of the fan head; a base assembly 8, connected to the fan head assembly 7, for supporting the fan head assembly 7; and a variable airflow structure as described above, wherein the variable airflow structure is disposed within the head support 72 and located behind the front mesh housing 73.

[0060] In this embodiment, the head support 72 includes a circular frame at the front end and a crossbar at the rear end. The circular frame is used to accommodate the variable air duct structure, and the crossbar is used to install the fan blade motor 74. The fan head assembly 7 also includes the fan blade motor 74 and fan blades. The fan blade motor 74 is fixed to the crossbar of the head support 72, and the fan blades are connected to the output shaft of the fan blade motor 74. The fan blades are located within the circular frame of the head support 72, behind the variable air duct structure. The airflow generated by the rotation of the fan blades is a basically uniform axial airflow before entering the variable air duct structure. After being guided by multiple arc-shaped guide vanes 2 of the variable air duct structure, the airflow shape and output direction change with the swing angle of the guide vanes 2, and finally output outward through the front mesh housing 73 in a set direction and shape. By adjusting the swing angle of the guide vanes 2 driven by the stepper motor 3, the airflow can be actively shaped before leaving the fan head, realizing flexible switching of various air outlet effects such as wide-area gentle air delivery, local concentrated strong wind, and multi-angle circulating air sweeping.

[0061] like Figure 8 As shown, the base assembly 8 includes a base 81 and two connecting arms 82. The lower ends of the two connecting arms 82 are connected to the base 81, and the upper ends of the two connecting arms 82 are respectively hinged to the left and right sides of the head support 72. The base assembly 8 also includes a first drive motor, which is mounted on the connecting arms 82 or the head support 72, and is used to drive the head support 72 to swing up and down relative to the connecting arms 82. The base 81 includes an upper base 81, a lower base 81, and a second drive motor. The upper base 81 is rotatably mounted on the lower base 81; the second drive motor is mounted inside the base 81 and is used to drive the upper base 81 to rotate horizontally relative to the lower base 81.

[0062] In terms of structural layout, the head bracket 72 serves as the core support component of the fan head. Its front circular frame accommodates and fixes the variable air duct structure, while its rear crossbar fixes and installs the fan blade motor 74. The fan blades are installed on the output shaft of the fan blade motor 74, located inside the circular frame and behind the variable air duct structure, allowing the airflow generated by the rotation of the fan blades to directly enter the variable air duct structure for guidance. The rear mesh shell 71 and the front mesh shell 73 are respectively fastened to the rear and front sides of the head bracket 72, together forming the protective shell of the fan head, which provides safety protection for the internal fan blade motor 74, fan blades, and variable air duct structure, while ensuring unobstructed airflow.

[0063] In the structural layout of the base assembly 8, the lower ends of the two connecting arms 82 are fixedly connected to the upper base 81, and the upper ends are respectively connected to the hinge points on the left and right sides of the head bracket 72, forming a stable double-arm support structure to ensure that the fan head is evenly stressed and moves smoothly during the up-and-down swinging process; the first drive motor is installed on the connecting arm 82 or the head bracket 72, and its output shaft is connected to the hinge shaft of the head bracket 72 through the transmission structure. By controlling the rotation direction and angle of the first drive motor, the elevation angle of the fan head can be precisely adjusted; the lower base 81 serves as the stable foundation of the whole machine, and the upper base 81 is rotatably installed on the lower base 81. The second drive motor is installed inside the base 81, and its output shaft is connected to the upper base 81 through transmission, driving the upper base 81 together with the connecting arm 82 and the fan head assembly 7 to rotate in the horizontal plane, realizing horizontal oscillating air delivery.

[0064] During operation, the fan blade motor 74 drives the fan blades to rotate and generate axial airflow. The airflow enters the variable air duct structure and is guided by the guide vanes 2 to output from the front mesh housing 73 in a set direction and shape. The stepper motor 3 adjusts the swing angle of the guide vanes 2 according to the control command to change the air outlet shape in real time. The first drive motor drives the fan head to swing up and down as needed to adjust the air supply angle. The second drive motor drives the upper base 81 to rotate horizontally as needed to achieve horizontal oscillating air supply.

[0065] The fan of this invention achieves a comprehensive improvement in three-dimensional airflow direction control and a significant expansion of airflow coverage. The variable air duct structure is responsible for adjusting the airflow pattern and near-field direction, the first drive motor is responsible for adjusting the vertical elevation angle, and the second drive motor is responsible for adjusting the horizontal direction. The three work together to form a composite airflow control in three dimensions: airflow pattern, vertical angle, and horizontal direction. Compared with traditional fans that only have a single oscillation function, the airflow direction adjustment range and airflow pattern diversity of this invention are qualitatively improved, which can fully meet the personalized airflow needs of different scenarios and postures.

[0066] The integration of the variable air duct structure significantly enhances the fan's added value. Without altering the overall dimensions of the fan head, the variable air duct structure is seamlessly integrated into the fan head through a compact layout within a circular frame. This allows for a substantial expansion of product functionality without a significant increase in size or weight, facilitating market differentiation. The separate, rotatable base structure of the upper and lower bases 81 fully integrates the horizontal oscillation function within the base 81. The connecting arm 82 and the entire structure above the fan head rotate synchronously with the upper base 81. The transmission chain is simple, the rotation is smooth, and the stable center of gravity of the base 81 effectively ensures the overall stability of the fan during horizontal rotation.

[0067] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0068] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A variable air duct structure, characterized in that, include: The rotating frame, in a ring shape, is positioned in the direction of the fan's airflow. Multiple air guide blades are arranged at intervals along the circumference of the rotating frame. Each air guide blade has a gear at one end, and the gear meshes with a meshing structure provided on the rotating frame. The drive assembly includes a stepper motor and a guide vane shaft, the guide vane shaft being gear-driven connected to one of the guide vanes; The stepper motor drives the guide vanes connected to the guide vane shaft to swing through the guide vane shaft, and then drives all other guide vanes to swing synchronously through the rotating frame, so as to change the air outlet direction or air outlet pattern of the variable air duct structure.

2. The variable air duct structure according to claim 1, characterized in that, The meshing structure consists of several toothed racks arranged on the inner side of the rotating frame, with the gears meshing one-to-one with the toothed racks.

3. The variable air duct structure according to claim 1, characterized in that, The drive assembly also includes a torque limiter connected between the output shaft of the stepper motor and the guide vane shaft.

4. The variable air duct structure according to claim 3, characterized in that, The torque limiter includes a limiter body, a limiter top cover, and a limiter bottom cover. The top surface of the limiter body is provided with a slot, the limiter top cover is provided with a limiting block that mates with the slot, and the center of the limiter top cover is provided with a D-shaped hole. One end of the guide vane shaft is inserted into the D-shaped hole to achieve a transmission connection. The limiter bottom cover is provided with a through hole, the output shaft of the stepper motor is inserted into the through hole, and the limiter bottom cover is connected to the limiter body.

5. The variable air duct structure according to claim 4, characterized in that, The slot is a straight slot, and the limiting block is a straight limiting block; the through hole is a long strip hole or a racetrack-shaped hole.

6. The variable air duct structure according to claim 1, characterized in that, It also includes a circular louvered bottom shell, the louvered bottom shell having a circular groove on its circumference, and the rotating frame being rotatably assembled in the circular groove; The louvered bottom shell is provided with several stroke limiting grooves evenly distributed along the inner side of the annular groove. The meshing structure of the rotating frame is placed in the stroke limiting groove to limit the rotation angle range of the rotating frame.

7. The variable air duct structure according to claim 6, characterized in that, It also includes a circular louvered top shell, with the rotating frame and multiple air guide blades encapsulated between the louvered top shell and the louvered bottom shell.

8. The variable air duct structure according to claim 7, characterized in that, The top and bottom shells of the louvers are provided with a plurality of pivoting assembly holes; each of the guide vanes has an integrally protruding upper pivoting shaft head at the top and a integrally protruding lower pivoting shaft head at the bottom; the upper pivoting shaft head is inserted into the corresponding pivoting assembly hole of the top shell of the louvers, and the lower pivoting shaft head is inserted into the corresponding pivoting assembly hole of the bottom shell of the louvers, so that the gear can rotate freely around its own pivoting shaft head.

9. The variable air duct structure according to claim 1, characterized in that, The air guide blade is arc-shaped, and the length direction of the air guide blade is defined from one end of the gear to the free end. The width direction of the air guide blade is perpendicular to the length direction. The air guide blade is curved in an arc shape in the length direction. The air guide blade has a first half blade close to the fan blade and a second half blade away from the fan blade in the width direction. The first half blade is aligned with the airflow direction, and the second half blade is bent to one side.

10. A fan with a variable air duct structure, characterized in that, include: The fan head assembly includes a rear grille housing, a head bracket, and a front grille housing. The rear grille housing and the front grille housing are respectively connected to the rear and front sides of the head bracket, and together they form the outer shell of the fan head. A base assembly, connected to the fan head assembly, is used to support the fan head assembly; And the variable air duct structure as described in any one of claims 1 to 9, wherein the variable air duct structure is disposed within the head support and located behind the front mesh housing.

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