A rear cover structure, a fan cover and a fan device

Abstract

This utility model provides a rear cover structure, a fan cover, and a fan device, relating to the field of fan technology. The rear cover structure includes a rear cover body and a connecting shaft. The rear cover body includes a mesh cover and a mounting base, with the mounting base and mesh cover being an integral structure. Along the axial direction of the connecting shaft, one end of the connecting shaft is configured to be detachably connected to the fan blade structure, the middle part of the connecting shaft is rotatably connected to the mounting base, and the other end of the connecting shaft is provided with a coupling structure. Furthermore, the connecting shaft is configured to be coupled and driven to the output end of a drive motor through the coupling structure. The rear cover structure of this embodiment effectively reduces the probability of noise from the fan device.

Description

Technical Field

[0001] This utility model relates to the field of fan technology, and more specifically, to a rear cover structure, a fan cover, and a fan device. Background Technology

[0002] In some fan devices, in order to achieve quick separation between the fan blade structure and the motor shaft, a connecting shaft is added to the fan blade structure to couple with the motor shaft. During assembly, the connecting shaft passes through the rear cover structure and connects to the motor shaft.

[0003] However, consumers regularly disassemble fans for cleaning. Because the connection between the fan blades and the shaft is flexible, the position of the fan blades and motor shaft may change after repeated disassembly. This can cause the centerline of the fan blades and motor shaft to shift, resulting in eccentricity during rotation, especially at high speeds. This eccentricity leads to noticeable noise during fan operation. Utility Model Content

[0004] To address the aforementioned problems, this utility model provides a rear cover structure, a fan cover, and a fan device.

[0005] In a first aspect, this utility model provides a rear cover structure, including a rear cover body and a connecting shaft; the rear cover body includes a mesh cover and a mounting base, the mounting base and the mesh cover being an integral structure; along the axial direction of the connecting shaft, one end of the connecting shaft is configured to be detachably connected to the fan blade structure, the middle part of the connecting shaft is rotatably connected to the mounting base, and the other end of the connecting shaft is provided with a coupling structure; and the connecting shaft is configured to be coupled and driven to the output end of the drive motor through the coupling structure.

[0006] Optionally, the rear cover structure also includes a bearing; the bearing is mounted on the mounting base, and the connecting shaft is fixedly connected to the inner ring of the bearing.

[0007] Optionally, the mounting base is provided with a mounting cavity, and the bearing is fixed in the mounting cavity; along the axial direction of the connecting shaft, the mounting cavity is provided with a first opening and a second opening on the mounting base; the first opening is configured to allow one end of the connecting shaft connected to the fan blade structure to pass through; the second opening is configured to allow one end of the connecting shaft with a coupling structure to pass through.

[0008] Optionally, the rear cover structure further includes a baffle fixed at the first opening and in contact with one axial end face of the bearing; the projection of the second opening on the bearing is located within the outline of the bearing, and the inner wall of the mounting cavity having the second opening is in contact with the other axial end face of the bearing.

[0009] Optionally, the connecting shaft is provided with a fan blade structure connecting part, and the fan blade structure connecting part is located on the outside of the mesh cover along the axial direction of the connecting shaft.

[0010] Optionally, the connecting shaft includes a first shaft body, a second shaft body, and a third shaft body arranged coaxially; the first shaft body, the second shaft body, and the third shaft body are connected sequentially along the axial direction of the connecting shaft; the projections of the first shaft body and the third shaft body onto the second shaft body are both located within the contour range of the second shaft body; the first shaft body and the second shaft body have different shapes along a plane perpendicular to the axial direction of the connecting shaft; the first shaft body is configured to be detachably connected to the fan blade structure, the second shaft body is rotatably connected to the mounting base, and the third shaft body is provided with the coupling structure.

[0011] Optionally, the outer contour of the coupling structure is non-circular along a plane perpendicular to the axial direction of the connecting shaft; the coupling structure is threadedly connected to the connecting shaft, and the tightening direction of the coupling structure is opposite to the rotation direction of the fan blade structure.

[0012] Secondly, this utility model provides a wind shield, including a front shield structure and a rear shield structure as described above; the front shield structure and the rear shield structure are detachably connected.

[0013] Optionally, the fan cover further includes a fan blade structure and a locking element; the cross-sectional shape of the connecting shaft of the rear cover structure is non-circular along a plane perpendicular to the axial direction of the connecting shaft; the fan blade structure is provided with a through hole, the shape of which matches the cross-sectional shape of the connecting shaft; the fan blade structure is sleeved onto the connecting shaft through the through hole; the locking element is disposed on the connecting shaft and configured to lock the fan blade structure onto the connecting shaft.

[0014] Thirdly, this utility model provides a fan device, including a head and a fan shroud as described above; the rear cover structure of the fan shroud is installed on the head.

[0015] Compared with related technologies, the beneficial effects of this utility model are as follows:

[0016] The rear cover structure integrates the connecting shaft into the rear cover body, achieving an efficient transmission connection between the fan blade structure and the drive motor. Specifically, along the axial direction of the connecting shaft, one end is designed for a detachable connection to the fan blade structure, facilitating quick assembly and disassembly. The middle part of the connecting shaft is rotatably connected to the mounting base of the rear cover body, ensuring flexible rotation. The other end of the connecting shaft is coupled to the output end of the drive motor via a coupling structure. This design eliminates the need to disassemble the connecting shaft when removing the fan blade structure, thus avoiding changes in the position of the fan blade structure and the motor shaft due to repeated assembly and disassembly. Compared to traditional fan blade structures with an integrated connecting shaft, this design significantly reduces the probability of misalignment between the fan blade structure and the motor shaft centerline, thereby reducing the possibility of eccentricity during fan blade rotation and effectively reducing noise caused by eccentricity. Simultaneously, the other end of the connecting shaft is coupled to the output end of the drive motor via a coupling structure. This coupling method ensures smooth and reliable power transmission, reducing vibration and noise caused by uneven power transmission. In addition, the rear cover structure, by designing the mesh cover and mounting base as an integrated structure, effectively avoids the misalignment of the connecting shaft caused by assembly gaps and loose component connections in traditional split designs. This integrated design significantly reduces the noise during fan operation.

[0017] In summary, the rear cover structure of this utility model effectively reduces the probability of noise from the fan device in multiple ways, providing users with a quieter and more reliable user experience. Attached Figure Description

[0018] Figure 1 This is a cross-sectional view of the rear cover structure according to an embodiment of the present utility model;

[0019] Figure 2 This is a schematic diagram of the rear cover structure according to an embodiment of the present utility model;

[0020] Figure 3 This is a cross-sectional view of the rear cover body according to an embodiment of the present utility model;

[0021] Figure 4 This is a schematic diagram of the structure of the rear cover body according to an embodiment of the present utility model. Figure 1 ;

[0022] Figure 5 This is a schematic diagram of the structure of the rear cover body according to an embodiment of the present utility model. Figure 2 ;

[0023] Figure 6 This is a schematic diagram of the connecting shaft in an embodiment of the present utility model;

[0024] Figure 7 This is a schematic diagram of the structure of the wind shield according to an embodiment of the present utility model;

[0025] Figure 8 This is a partial schematic diagram of the wind shield according to an embodiment of the present utility model;

[0026] Figure 9 This is a partial schematic diagram of the fan device according to an embodiment of the present utility model.

[0027] Explanation of reference numerals in the attached figures:

[0028] 100. Rear cover body; 101. Mesh cover; 102. Mounting base; 1021. Mounting cavity; 1022. First opening; 1023. Second opening; 1024. Strip-shaped protrusion; 200. Connecting shaft; 201. First shaft body; 202. Second shaft body; 203. Third shaft body; 300. Coupling structure; 400. Bearing; 500. Baffle; 600. Front cover structure; 700. Fan blade structure; 701. Through hole; 702. Blade; 800. Locking element; 900. Head. Detailed Implementation

[0029] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Although some embodiments of this utility model are shown in the drawings, it should be understood that this utility model can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this utility model. It should be understood that the drawings and embodiments of this utility model are for illustrative purposes only and are not intended to limit the scope of protection of this utility model.

[0030] In the attached diagram, the Z-axis represents the vertical direction, i.e., up and down, with the positive direction of the Z-axis representing up and the negative direction representing down. The X-axis represents the horizontal direction and is designated as the front and back position, with the positive direction of the X-axis representing the front and the negative direction representing the back. The Y-axis represents the left and right position, with the positive direction of the Y-axis representing the right and the negative direction representing the left. It should be noted that the aforementioned representations of the Z, Y, and X axes are merely for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0031] In the description of this application, it should be understood that the terms "height", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0032] like Figure 1 , 2 As shown, the rear cover structure of this utility model embodiment includes a rear cover body 100 and a connecting shaft 200; the rear cover body 100 includes a mesh cover 101 and a mounting base 102, the mounting base 102 and the mesh cover 101 are an integral structure; along the axial direction of the connecting shaft 200, one end of the connecting shaft 200 is configured to be detachably connected to the fan blade structure 700, the middle part of the connecting shaft 200 is rotatably connected to the mounting base 102, and the other end of the connecting shaft 200 is provided with a coupling structure 300; and the connecting shaft 200 is configured to be coupled and driven to the output end of the drive motor through the coupling structure 300.

[0033] It should be noted that the axial direction of connecting shaft 200 refers to, for example, Figure 1 The direction of the X-axis is shown.

[0034] Specifically, the rear cover body 100 is a plastic part, molded using a one-piece injection molding method. In other words, the mounting base 102 and the mesh cover 101 are a single integrated structure, meaning that the mounting base 102 and the mesh cover 101 are molded as a single unit. For example... Figure 2 , 3 As shown, the front end of the mesh cover 101 has an opening, and the rear end has a cavity; the mounting base 102 is disposed inside the mesh cover 101; along the axial direction of the connecting shaft 200 (that is, the direction of the X-axis), the front end of the connecting shaft 200 is detachably connected to the fan blade structure 700, the middle part of the connecting shaft 200 is rotatably connected to the mounting base 102, and the other end of the connecting shaft 200 extends toward the cavity and is provided with a coupling structure 300.

[0035] In this embodiment, the rear cover structure integrates the connecting shaft 200 into the rear cover body 100, achieving an efficient transmission connection between the fan blade structure 700 and the drive motor. Specifically, along the axial direction of the connecting shaft 200, one end of the connecting shaft 200 is designed for detachable connection with the fan blade structure 700, facilitating quick assembly and disassembly of the fan blade structure 700 by the user; the middle part of the connecting shaft 200 is rotatably connected to the mounting base 102 of the rear cover body 100, ensuring flexible rotation of the connecting shaft 200; and the other end of the connecting shaft 200 is coupled to the output end of the drive motor through the coupling structure 300. This design eliminates the need to disassemble the connecting shaft 200 when disassembling the fan blade structure 700, thus avoiding changes in the position of the fan blade structure 700 and the motor shaft due to repeated assembly and disassembly. Compared to the traditional fan blade structure 700 with an integrated connecting shaft 200, this design significantly reduces the probability of the fan blade structure 700 deviating from the center line of the motor shaft, thereby reducing the possibility of eccentricity during rotation and effectively reducing noise caused by eccentricity. Simultaneously, the other end of the connecting shaft 200 is coupled to the output end of the drive motor via a coupling structure 300. This coupling method ensures smooth and reliable power transmission, reducing vibration and noise caused by uneven power transmission. Furthermore, the rear cover structure, by designing the mesh cover 101 and the mounting base 102 as an integrated structure, effectively avoids the eccentricity of the connecting shaft 200 caused by assembly gaps and loose component connections in traditional split designs. This integrated design significantly reduces noise during fan operation.

[0036] In summary, the rear cover structure of this utility model effectively reduces the probability of noise from the fan device in multiple ways, providing users with a quieter and more reliable user experience.

[0037] Optionally, the rear cover structure also includes a bearing 400; the bearing 400 is mounted on the mounting base 102, and the connecting shaft 200 is fixedly connected to the inner ring of the bearing 400.

[0038] Specifically, the number of bearings 400 can be one, two, or three, etc., without restriction, depending on actual needs. For example... Figure 1 As shown, there are two bearings 400. The two bearings 400 are arranged sequentially on the mounting base 102 along the axial direction of the connecting shaft 200 (that is, the direction of the X-axis). The connecting shaft 200 passes through the inner rings of the two bearings 400 in sequence and is fixedly connected to the inner rings of the two bearings 400.

[0039] In this optional embodiment, the introduction of bearing 400 can effectively reduce the friction of connecting shaft 200 during rotation, ensuring smooth rotation of connecting shaft 200, thereby reducing noise and vibration caused by friction. At the same time, the high precision and stability of bearing 400 further ensure the coaxiality of connecting shaft 200 and motor shaft, avoiding fan blade structure 700 wobbling and noise problems caused by eccentricity.

[0040] Optionally, the mounting base 102 is provided with a mounting cavity 1021, and the bearing 400 is fixed in the mounting cavity 1021; along the axial direction of the connecting shaft 200, the mounting cavity 1021 is provided with a first opening 1022 and a second opening 1023 on the mounting base 102; the first opening 1022 is configured to allow one end of the connecting shaft 200 connected to the fan blade structure 700 to pass through; the second opening 1023 is configured to allow one end of the connecting shaft 200 provided with the coupling structure 300 to pass through.

[0041] Specifically, such as Figure 3 As shown, the mounting base 102 has a mounting cavity 1021 inside, and the bearing 400 is fixed in the mounting cavity 1021. The position of the bearing 400 can be limited by the static friction between the circumferential sidewall of the bearing 400 and the inner wall of the mounting cavity 1021; as Figure 4 As shown, the mounting cavity 1021 has a first opening 1022 at the front end of the mounting base 102, and the first opening 1022 allows one end of the connecting shaft 200 connected to the fan blade structure 700 to pass through; as Figure 5 As shown, the mounting cavity 1021 has a second opening 1023 at the rear end of the mounting base 102, and the second opening 1023 allows one end of the connecting shaft 200 with the coupling structure 300 to pass through.

[0042] In this optional embodiment, by providing a mounting cavity 1021 within the mounting base 102 and fixing the bearing 400 within the mounting cavity 1021, stable support and precise rotation of the connecting shaft 200 are ensured. Simultaneously, the two openings of the mounting cavity 1021 are optimized for different functional ends of the connecting shaft 200: the first opening 1022 allows the end of the connecting shaft 200 connected to the fan blade structure 700 to pass smoothly through, ensuring flexible installation and disassembly of the fan blade structure 700; the second opening 1023 provides a channel for the end of the connecting shaft 200 equipped with the coupling structure 300, facilitating efficient power transmission with the output end of the drive motor.

[0043] Furthermore, the inner wall of the mounting cavity 1021 is provided with a plurality of evenly distributed strip-shaped protrusions 1024. The strip-shaped protrusions 1024 extend along the axial direction of the connecting shaft 200 (that is, the direction where the X-axis is located), and one end of the strip-shaped protrusions 1024 extends to the first opening 1022. In this way, after the bearing 400 is installed in the mounting cavity 1021, the plurality of strip-shaped protrusions 1024 can clamp the bearing 400 in the mounting cavity 1021.

[0044] Optionally, the rear cover structure also includes a baffle 500, which is fixed at the first opening 1022 and contacts one axial end face of the bearing 400; the projection of the second opening 1023 on the bearing 400 is located within the outline of the bearing 400, and the inner wall of the mounting cavity 1021 with the second opening 1023 contacts the other axial end face of the bearing 400.

[0045] Specifically, such as Figure 2 As shown, the baffle 500 is generally annular, and the diameter of its inner ring is smaller than the diameter of the outer ring of the bearing 400. The baffle 500 is detachably installed at the first opening 1022 of the mounting base 102 and contacts the front end face of the bearing 400. The second opening 1023 is circular, and the diameter of the second opening 1023 is smaller than the diameter of the outer ring of the bearing 400. That is to say, the projection of the second opening 1023 on the bearing 400 is within the outline of the bearing 400. After the bearing 400 is installed in the mounting cavity 1021, the inner wall of the mounting cavity 1021 with the second opening 1023 contacts the rear end face of the bearing 400.

[0046] In this optional embodiment, by providing a baffle 500 in the rear cover structure and fixing it at the first opening 1022 to contact one axial end face of the bearing 400, while designing the second opening 1023 within the projection range of the bearing 400 and making the inner wall of the mounting cavity 1021 contact the other axial end face of the bearing 400, this design achieves axial limiting and stable support for the bearing 400. This effectively prevents axial movement of the bearing 400 and avoids displacement of the bearing 400 due to vibration or impact.

[0047] In other embodiments, the baffle 500 may also be straight or L-shaped, etc. There are no restrictions here, and it depends on the actual needs.

[0048] Optionally, the connecting shaft 200 is provided with a fan blade connecting part, which is located on the outside of the mesh cover 101 along the axial direction of the connecting shaft 200.

[0049] It is important to understand that the rear cover structure is the main component for air intake. Therefore, when designing the rear cover structure, it is necessary to optimize its structure in order to increase the air intake volume.

[0050] Specifically, the front end of the connecting shaft 200 is provided with a fan blade connecting part, and along the axial direction of the connecting shaft 200 (that is, the direction of the X-axis), the fan blade connecting part is located on the front side of the mesh cover 101. Thus, after the fan blade connecting part is connected to the fan blade structure 700, most or even all of the fan blade structure 700 can be located on the front side of the mesh cover 101.

[0051] In this optional embodiment, the fan blade connection allows the fan blade structure 700 to protrude beyond the front end of the mesh cover 101 after installation. Since the fan blade structure 700 is located on the front side of the mesh cover 101, its air intake surface can be more directly exposed to the airflow, thereby expanding the air intake range and enabling the fan blade structure 700 to more effectively draw in more air volume.

[0052] Optionally, the connecting shaft 200 includes a first shaft body 201, a second shaft body 202, and a third shaft body 203 coaxially arranged; the first shaft body 201, the second shaft body 202, and the third shaft body 203 are sequentially connected along the axial direction of the connecting shaft 200; the projections of the first shaft body 201 and the third shaft body 203 onto the second shaft body 202 are both located within the outline of the second shaft body 202; the first shaft body 201 and the second shaft body 202 have different shapes along a plane perpendicular to the axial direction of the connecting shaft 200; the first shaft body 201 is configured to be detachably connected to the fan blade structure 700, the second shaft body 202 is rotatably connected to the mounting base 102, and the third shaft body 203 is provided with a coupling structure 300.

[0053] Specifically, such as Figure 6 As shown, the connecting shaft 200 is rod-shaped and includes a first shaft body 201, a second shaft body 202, and a third shaft body 203 that are coaxially arranged and sequentially connected along the axial direction of the connecting shaft 200. The projections of the first shaft body 201 and the third shaft body 203 onto the second shaft body 202 are both within the outline of the second shaft body 202. That is, a stepped structure is formed at the junction of the first shaft body 201 and the second shaft body 202, and at the junction of the second shaft body 202 and the third shaft body 203. At the same time, on a plane perpendicular to the axial direction of the connecting shaft 200 (i.e., the ZY plane), the shape of the first shaft body 201 is semi-circular, and the shape of the second shaft body 202 is circular. During assembly, the first shaft body 201 is detachably connected to the fan blade structure 700, so the fan blade connecting part is set on the first shaft body 201; the second shaft body 202 is rotatably connected to the mounting base 102. Since the mounting base 102 is equipped with a bearing 400, the second shaft body 202 is used to connect with the inner ring of the bearing 400; the third shaft body 203 is provided with a coupling structure 300 for coupling transmission with the motor shaft.

[0054] In this optional embodiment, since the first shaft 201 and the second shaft 202 have different shapes on a plane perpendicular to the axial direction of the connecting shaft 200, and the projections of the first shaft 201 and the third shaft 203 onto the second shaft 202 are both within the contour range of the second shaft 202, this structure ensures that the fan blade structure 700, the mounting base 102, and the motor shaft can only be installed in the correct order and manner. For example, the fan blade structure 700 can only be matched and connected to the first shaft 201 through its through hole 701, and will not be mistakenly installed to the second shaft 202 or the third shaft 203.

[0055] Optionally, the outer contour shape of the coupling structure 300 is non-circular along a plane perpendicular to the axis of the connecting shaft 200.

[0056] Specifically, the coupling structure 300 is a separate component that is detachably connected to the rear end of the connecting shaft 200. The outer contour of the coupling structure 300 is non-circular, such as a straight line, a cross, or a star shape, on a plane perpendicular to the axis of the connecting shaft 200 (i.e., the ZY plane).

[0057] In this optional embodiment, the outer contour of the coupling structure 300 is designed to be non-circular. After the connecting shaft 200 is coupled to the driven coupling structure on the motor shaft through the coupling structure 300, relative rotation problems that may occur during coupled transmission can be effectively avoided. Compared with the circular coupling structure 300, the non-circular coupling structure 300 provides more precise mechanical fit and higher torsional resistance through its unique geometry. During transmission, this non-circular design ensures a tight and stable connection between the connecting shaft 200 and the output end of the drive motor, preventing relative rotation caused by torque transmission, thereby improving the efficiency and reliability of power transmission.

[0058] Optionally, the coupling structure 300 is threadedly connected to the connecting shaft 200, and the tightening direction of the coupling structure 300 is opposite to the rotation direction of the fan blade structure 700.

[0059] Specifically, the rear end of the connecting shaft 200 is provided with an external thread structure, and the coupling structure 300 is provided with a threaded hole. The coupling structure 300 is threadedly connected to the part of the connecting shaft 200 that is provided with an external thread structure through the threaded hole. The tightening direction of the coupling structure 300 is counterclockwise, which is opposite to the clockwise rotation direction of the fan blade structure 700.

[0060] In this optional embodiment, the torque generated during the rotation of the fan blade structure 700 is opposite in direction to the tightening torque of the coupling structure 300, which not only plays a self-locking role and enhances the stability of the connection, but also reduces noise and vibration problems caused by loosening.

[0061] Another embodiment of the wind shield of this utility model includes a front shield structure 600 and a rear shield structure as described above; as Figure 7 As shown, the front cover structure 600 is detachably connected to the rear cover structure.

[0062] In this embodiment, the connection method between the front cover structure 600 and the rear cover structure includes, but is not limited to, snap-fit, plug-in, or screw connection. No limitation is imposed here; the method depends on actual needs.

[0063] The wind shield in this embodiment has the same beneficial effects as the rear shield structure described above compared to related technologies, so it will not be described again here.

[0064] Optionally, the fan cover also includes a fan blade structure 700 and a locking member 800; the cross-sectional shape of the connecting shaft 200 of the rear cover structure is non-circular along a plane perpendicular to the axial direction of the connecting shaft 200; the fan blade structure 700 is provided with a through hole 701, the shape of which matches the cross-sectional shape of the connecting shaft 200; the fan blade structure 700 is sleeved on the connecting shaft 200 through the through hole 701; the locking member 800 is disposed on the connecting shaft 200 and configured to lock the fan blade structure 700 to the connecting shaft 200.

[0065] Specifically, such as Figure 8 As shown, on a plane perpendicular to the axial direction of the connecting shaft 200 (i.e., the ZY plane), the cross-sectional shape of the connecting shaft 200 is semi-circular; the hub portion of the fan blade structure 700 is provided with a through hole 701, the shape of which is a semi-circle matching the cross-sectional shape of the connecting shaft 200; the fan blade structure 700 is sleeved on the connecting shaft 200 through the through hole 701 and contacts the step of the connecting shaft 200 or the inner ring of the bearing 400; the locking member 800 is a knob nut, which is threadedly connected to the connecting shaft 200, and the tightening direction of the knob nut is opposite to the rotation direction of the fan blade structure 700 and contacts the front end face of the fan blade structure 700.

[0066] In this optional embodiment, by designing the cross-section of the connecting shaft 200 to be non-circular and matching the shape of the through hole 701 of the fan blade structure 700 with the cross-sectional shape of the connecting shaft 200, this design effectively prevents relative rotation of the fan blade structure 700 on the connecting shaft 200. During fan operation, the high-speed rotation of the fan blade structure 700 generates significant centrifugal force and vibration, potentially causing loosening between the fan blade structure 700 and the connecting shaft 200, thus affecting the fan's operational stability and performance. However, due to the non-circular design of the connecting shaft 200 and the through hole 701, a tight mechanical fit is achieved between the fan blade structure 700 and the connecting shaft 200, eliminating the possibility of relative rotation. Furthermore, the locking member 800 further secures the fan blade structure 700 to the connecting shaft 200, further enhancing the reliability of the connection.

[0067] Optionally, such as Figure 8 As shown, the fan blade structure 700 includes multiple blades 702. The blades 702 are twisted arc surfaces. The edge facing the front end of the fan blade structure 700 forms the leading edge of the blade 702, and the edge facing the rear end of the fan blade structure 700 forms the trailing edge of the blade 702. From the root of the blade 702 to the tip, the distance between the leading edge and the trailing edge of the blade 702 gradually increases.

[0068] In this optional embodiment, the twisted arc shape of the blade 702 allows air to be guided more smoothly as it flows over the blade 702, reducing air resistance and turbulence generation, thereby improving the fan's air delivery efficiency and reducing operating noise. Furthermore, the distance between the leading and trailing edges of the blade 702 gradually increases from the blade root to the blade tip. This gradual spacing design further optimizes the acceleration and guidance of the airflow. At the blade root, a smaller spacing helps to improve the initial acceleration of the air, while at the blade tip, a larger spacing better adapts to high-speed airflow, further increasing the air's projectile speed and distance.

[0069] Another embodiment of the fan device of this utility model includes a fan head 900 and a fan shroud as described above; as Figure 9 As shown, the rear cover structure of the wind shield is installed at the nose 900.

[0070] In this embodiment, the connection method between the rear cover structure and the head 900 includes, but is not limited to, snap-fit, plug-in, or screw connection. No limitation is imposed here; the method depends on actual needs.

[0071] The fan device in this embodiment has the same beneficial effects as the rear cover structure described above relative to the related technology, so it will not be described again here.

[0072] Although the present invention has been disclosed above, its protection scope is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the protection scope of the present invention.

Claims

1. A rear cover structure characterized by, It includes a rear cover body (100) and a connecting shaft (200); the rear cover body (100) includes a mesh cover (101) and a mounting base (102), the mounting base (102) and the mesh cover (101) are an integral structure; along the axial direction of the connecting shaft (200), one end of the connecting shaft (200) is configured to be detachably connected to the fan blade structure (700), the middle part of the connecting shaft (200) is rotatably connected to the mounting base (102), and the other end of the connecting shaft (200) is provided with a coupling structure (300); and the connecting shaft (200) is configured to be coupled and driven to the output end of the drive motor through the coupling structure (300).

2. The rear cover structure according to claim 1, characterized by It also includes a bearing (400); the bearing (400) is mounted on the mounting base (102), and the connecting shaft (200) is fixedly connected to the inner ring of the bearing (400).

3. The rear cover structure according to claim 2, characterized by The mounting base (102) is provided with a mounting cavity (1021), and the bearing (400) is fixed in the mounting cavity (1021). Along the axial direction of the connecting shaft (200), the mounting cavity (1021) is provided with a first opening (1022) and a second opening (1023) on the mounting base (102). The first opening (1022) is configured to allow one end of the connecting shaft (200) connected to the fan blade structure (700) to pass through. The second opening (1023) is configured to allow one end of the connecting shaft (200) provided with a coupling structure (300) to pass through.

4. The rear cover structure according to claim 3, characterized by It also includes a baffle (500), which is fixed at the first opening (1022) and contacts one axial end face of the bearing (400); the projection of the second opening (1023) on the bearing (400) is located within the outline of the bearing (400), and the inner wall of the mounting cavity (1021) with the second opening (1023) contacts the other axial end face of the bearing (400).

5. The rear cover structure of claim 1, wherein The connecting shaft (200) is provided with a fan blade connecting part, and along the axial direction of the connecting shaft (200), the fan blade connecting part is located on the outside of the mesh cover (101).

6. The rear cover structure of claim 1, wherein The connecting shaft (200) includes a first shaft body (201), a second shaft body (202), and a third shaft body (203) arranged coaxially; the first shaft body (201), the second shaft body (202), and the third shaft body (203) are connected sequentially along the axial direction of the connecting shaft (200); the projections of the first shaft body (201) and the third shaft body (203) onto the second shaft body (202) are both located within the outline of the second shaft body (202); the first shaft body (201) and the second shaft body (202) have different shapes along a plane perpendicular to the axial direction of the connecting shaft (200); the first shaft body (201) is configured to be detachably connected to the fan blade structure (700), the second shaft body (202) is rotatably connected to the mounting base (102), and the third shaft body (203) is provided with the coupling structure (300).

7. The rear cover structure according to claim 1, characterized in that, Along a plane perpendicular to the axial direction of the connecting shaft (200), the outer contour of the coupling structure (300) is non-circular; the coupling structure (300) is threadedly connected to the connecting shaft (200), and the tightening direction of the coupling structure (300) is opposite to the rotation direction of the fan blade structure (700).

8. A wind shield, characterized in that, It includes a front cover structure (600) and a rear cover structure as described in any one of claims 1 to 7; the front cover structure (600) and the rear cover structure are detachably connected.

9. The wind shield according to claim 8, characterized in that, It also includes a fan blade structure (700) and a locking member (800); the cross-sectional shape of the connecting shaft (200) of the rear cover structure is non-circular along a plane perpendicular to the axial direction of the connecting shaft (200); the fan blade structure (700) is provided with a through hole (701), the shape of which matches the cross-sectional shape of the connecting shaft (200); the fan blade structure (700) is sleeved on the connecting shaft (200) through the through hole (701); the locking member (800) is disposed on the connecting shaft (200) and configured to lock the fan blade structure (700) to the connecting shaft (200).

10. A fan device, characterized in that, It includes a head unit (900) and a shroud as described in claim 9; the rear cover structure of the shroud is mounted on the head unit (900).

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