Portable fan

Abstract

The application relates to the fan field, and in particular to a portable fan, which comprises a fuselage, a fan main body is arranged on the fuselage; a fan base assembly, the fan base assembly comprises a lower seat body and an upper seat body sleeved on the lower seat body, the upper seat body is connected with the fuselage; the lower seat body has an assembly groove protruding towards the upper seat body; the upper seat body has an assembly column extending axially towards the lower seat body; the assembly groove has a preset depth along the axial direction of the assembly groove, the assembly column extends into and is inserted into the assembly groove along the axial direction of the assembly groove, and the extension length of the assembly column matches the preset depth of the assembly groove; the outer diameter of the assembly column is smaller than the inner diameter of the assembly groove, when the assembly column is inserted into the assembly groove, a preset gap is left between the outer circumferential surface of the assembly column and the inner groove wall of the assembly groove, and a bearing assembly is arranged in the preset gap. The problem of large friction and high noise caused by poor design of a rotating structure in the prior art is solved.

Description

Technical Field

[0001] This application relates to the field of fans, and more particularly to a portable fan. Background Technology

[0002] Portable fans, as a personal cooling tool, are widely used in various life and work scenarios such as outdoor travel, commuting, and office / study. Users not only expect them to have sufficient airflow and long battery life, but also demand quiet operation and stable reliability. This is especially true for products with automatic rotation functions to expand the airflow range, which place higher demands on the smoothness and quietness of the rotating structure.

[0003] Currently available portable automatic rotating fans on the market use a simple bushing sliding friction structure in the support part for their rotating mechanism. This type of solution suffers from high operating resistance due to sliding friction, is prone to noise, and causes rapid wear of components during use, leading to increased clearance and wobbling, which seriously affects service life and user experience.

[0004] Therefore, in order to solve the problems of high friction and high noise caused by poor design of the rotating structure in the existing technology, it is urgent to develop a new type of portable fan to solve the above technical problems. Summary of the Invention

[0005] The purpose of this application is to provide a portable fan to solve the problems of high friction and high noise caused by poor design of the rotating structure of portable fans in the prior art.

[0006] To achieve the above objectives, this application provides the following technical solution:

[0007] In a first aspect, this application provides a portable fan, comprising:

[0008] The body of the unit is equipped with the main fan body.

[0009] A fan base assembly, comprising a lower base and an upper base sleeved on the lower base, the upper base being connected to the body;

[0010] The lower seat has an assembly groove that protrudes toward the upper seat;

[0011] The upper seat has an assembly column that extends axially toward the lower seat.

[0012] The assembly column extends into the assembly groove along the axial direction of the assembly groove, and a preset gap is left between the outer circumferential surface of the assembly column and the inner wall of the assembly groove, and a bearing assembly is assembled in the preset gap.

[0013] Furthermore, the bearing assembly includes a first bearing and a second bearing;

[0014] The outer walls of both the first bearing and the second bearing are in contact with the groove wall of the assembly groove, and the inner walls of both the first bearing and the second bearing are in contact with the outer surface of the assembly column.

[0015] Furthermore, the first bearing and the second bearing are arranged at an axial distance along the assembly groove.

[0016] Furthermore, the inner side of the assembly groove is provided with a first step and a second step arranged at intervals along the axial direction of the assembly groove, and both the first step and the second step protrude inward along the radial direction of the assembly groove.

[0017] The outer periphery of the assembly column is provided with a first protruding ridge and a second protruding ridge arranged at intervals along the axial direction, and both the first protruding ridge and the second protruding ridge extend outward along the radial direction of the assembly column.

[0018] The first step and the first protruding ridge are staggered in the axial direction, and they are opposite each other in the radial direction of the assembly groove and the distance between them is adapted to the thickness of the first bearing, together forming a first constraint space that restricts the axial movement of the first bearing.

[0019] The second step and the second protrusion are staggered in the axial direction, and they are radially opposite each other along the assembly groove and the distance between them is adapted to the thickness of the second bearing, together forming a second constraint space that restricts the axial movement of the second bearing.

[0020] Furthermore, several constraint members are provided at the connection between the second step and the inner wall of the assembly groove;

[0021] The constraint member extends axially along the assembly groove and covers the axial range of the second bearing, protrudes radially inward along the assembly groove and its inner end is adapted to the outer circumferential surface of the outer ring of the second bearing, and a plurality of the constraint members are evenly spaced along the inner wall of the assembly groove.

[0022] Furthermore, it includes a stop ring component, wherein the assembly post is provided with an annular groove extending circumferentially thereon, and the stop ring component is embedded in the annular groove and partially protrudes from the outer circumferential surface of the assembly post.

[0023] The stop ring and the second convex ridge overlap in at least a portion of their radial direction.

[0024] Furthermore, the assembly column is a hollow column.

[0025] Furthermore, it includes a rotating assembly, which includes a motor fixedly connected to the upper body, an output gear connected to the output shaft of the motor, and a driven gear meshing with the output gear, the driven gear being fixedly mounted on the lower body.

[0026] Furthermore, the number of teeth of the driven gear is greater than the number of teeth of the output gear.

[0027] The technical solutions provided in this application have the following advantages compared with the prior art:

[0028] The portable fan provided in this application solves the problems of high operating friction resistance and noise caused by the sliding friction structure of the bushing in existing automatic rotating portable fans, as well as the rapid wear of components during long-term use leading to increased clearance and wobbling, which in turn affects product lifespan and user experience. This technical solution eliminates direct sliding contact between components at the source by setting an assembly groove in the lower body and an assembly column in the upper body, with the assembly column extending along the axis of the assembly groove and the extension length matching the preset depth of the assembly groove. At the same time, a preset gap is reserved when the two are in contact. This design eliminates direct sliding contact between components at the source, thereby avoiding the generation of sliding friction. The absence of sliding contact significantly reduces operating friction resistance, makes the fan rotate more smoothly, and completely reduces noise caused by sliding friction, improving the quietness of use. Attached Figure Description

[0029] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0032] Figure 1 An external structural diagram of a portable fan provided in an embodiment of this application;

[0033] Figure 2 An internal cross-sectional view of a portable fan provided in an embodiment of this application;

[0034] Figure 3 A structural diagram of a bearing assembly for a portable fan provided in an embodiment of this application;

[0035] Figure 4 This application provides a structural diagram of an assembly column and assembly slot for a portable fan, as shown in an embodiment.

[0036] Figure 5 This is a structural diagram of a drive component for a portable fan provided in an embodiment of this application.

[0037] Explanation of reference numerals in the attached figures:

[0038] 1. Fan body; 2. Fan casing; 3. Fan base assembly; 31. Upper base; 311. Assembly column; 3111. First protruding ridge; 3112. Second protruding ridge; 3113. Annular groove; 32. Lower base; 321. Assembly groove; 3211. First step; 3212. Second step; 3213. Constraint; 4. Bearing assembly; 41. First bearing; 42. Second bearing; 5. Rotating assembly; 51. Motor; 52. Output gear; 53. Driven gear; 6. Stop ring. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0041] For ease of description, spatial relative terms may be used in the text to describe the relative position or movement of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "front," "back," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure undergoes a positional flip, orientation change, or change of motion, these directional indications will change accordingly. For instance, an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0042] To address the issues of high friction and noise caused by poor design of the rotating structure in existing portable fans.

[0043] This application provides a portable fan in which the fan body 1 can rotate relative to the fan base assembly 3 when rotating, thereby reducing wear at the connection between the fan body 1 and the fan base and reducing noise generation.

[0044] Detailed, such as Figure 1 and Figure 2 As shown, this portable fan includes: a body 2, on which a fan body 1 is mounted; and a fan base assembly 3, which includes a lower base 32 and an upper base 31 sleeved on the lower base 32, the upper base 31 being connected to the body 2; the lower base 32 has a mounting groove 321 protruding toward the upper base 31; the upper base 31 has a mounting post 311 extending axially toward the lower base 32; the mounting groove 321 has a [missing information - likely a feature or characteristic] along its own axis. The mounting post 311 extends into and is inserted into the mounting groove 321 along the axial direction of the mounting groove 321 at a preset depth, and the extension length of the mounting post 311 matches the preset depth of the mounting groove 321; the outer diameter of the mounting post 311 is smaller than the inner diameter of the mounting groove 321; when the mounting post 311 is inserted into the mounting groove 321, a preset gap is left between the outer circumferential surface of the mounting post 311 and the inner wall of the mounting groove 321, and the bearing assembly 4 is assembled in the preset gap.

[0045] In this embodiment, the outer diameter of the mounting post 311 is designed to be smaller than the inner diameter of the mounting groove 321 so that the mounting post 311 can be smoothly inserted into the mounting groove 321. After the mounting post 311 is inserted, a preset gap will be formed between its outer wall and the inner wall of the mounting groove 321. The specific value of this gap can be set according to actual needs (e.g., 5mm, 8mm, etc.), as long as the gap size matches the width of the bearing assembly 4.

[0046] This clearance design prevents the outer wall of the assembly column 311 from directly contacting the inner wall of the assembly groove 321 when the upper seat 31 (connected to the assembly column 311) rotates relative to the lower seat 32 (connected to the assembly groove 321), thereby preventing sliding friction caused by direct contact between the two.

[0047] In addition, by placing the bearing assembly 4 at the gap, when the mounting post 311 rotates relative to the mounting groove 321, the bearing assembly 4 converts the sliding friction between the mounting post 311 and the mounting groove 321 into rolling friction.

[0048] In detail, the outer wall of the bearing is in close contact with the inner wall of the assembly groove 321, the inner wall of the bearing is in close contact with the outer wall of the assembly column 311, and rolling elements (such as balls or rollers) are provided between the inner and outer walls of the bearing.

[0049] When the assembly column 311 rotates relative to the assembly groove 321, the assembly column 311 will drive the inner wall of the bearing to rotate synchronously, thereby driving the rolling elements between the inner and outer walls to roll. At this time, the outer wall of the bearing remains relatively stationary because it is in contact with the inner wall of the assembly groove 321. The original sliding friction between the assembly column 311 and the assembly groove 321 is transformed into the rolling friction of the rolling elements inside the bearing.

[0050] Since the resistance of rolling friction is much smaller than that of sliding friction, this design can effectively reduce component wear during the process of "upper seat 31 rotating relative to lower seat 32" (i.e., fan operation), thereby reducing noise caused by wear.

[0051] The above technical solutions include a single-bearing design. While this design can solve the basic friction problem, in long-term use, a single bearing must bear the entire load transmitted by the assembly column 311, which is prone to accelerated wear due to stress concentration. To further improve the structural lifespan and stability, this solution preferably includes a bearing assembly 4 comprising a first bearing 41 and a second bearing 42.

[0052] Detailed, such as Figure 3 and Figure 4 As shown, in one embodiment, the bearing assembly 4 includes a first bearing 41 and a second bearing 42; the outer walls of the first bearing 41 and the second bearing 42 are in contact with the groove wall of the assembly groove 321, and the inner walls of the first bearing 41 and the second bearing 42 are in contact with the outer surface of the assembly column 311.

[0053] In this embodiment, the bearing assembly 4 includes a first bearing 41 and a second bearing 42. Compared with a configuration with only one bearing, the dual-bearing configuration can distribute the contact stress between the mounting column 311 and the mounting groove 321 to the two bearings, avoiding accelerated wear or failure of a single bearing due to long-term concentrated load, and extending the service life of the overall structure.

[0054] Furthermore, the first bearing 41 and the second bearing 42 are arranged axially spaced along the mounting groove 321. This arrangement allows the first bearing 41 and the second bearing 42 to form two-point support in the axial direction, dispersing the pressure transmitted by the mounting column 311 and avoiding stress concentration from a single-point support. When the fan rotates, the two-point supported bearings can more evenly bear the radial force of the mounting column 311, ensuring that the mounting column 311 rotates along a fixed axis without tilting or shifting due to uneven force. This design improves the load balance of the bearings, while ensuring the coaxiality of the fan during rotation, further enhancing rotational stability and reducing abnormal noise that may be caused by uneven force.

[0055] As the fan rotates, the bearing is subjected to forces in multiple directions. Although the axial two-point support of the dual bearings optimizes the force balance, the airflow reaction force will still cause the bearing to be subjected to an upward axial component force when the fan rotates. If there is no axial limit, the bearing is prone to move up and down along the axis of the assembly column 311, which will lead to the upper body 31 shaking and increased noise.

[0056] In response to this problem, such as Figure 4 As shown, the inner side of the assembly groove 321 is provided with a first step 3211 and a second step 3212 arranged at intervals along the axial direction of the assembly groove 321. Both the first step 3211 and the second step 3212 protrude inward along the radial direction of the assembly groove 321. The outer periphery of the assembly column 311 is provided with a first convex rib 3111 and a second convex rib 3112 arranged at intervals along the axial direction. Both the first convex rib 3111 and the second convex rib 3112 extend outward along the radial direction of the assembly column 311. The first step 3211 and the first convex rib 3111 are staggered in the axial direction, and they are opposite each other in the radial direction of the assembly groove 321, with a distance adapted to the thickness of the first bearing 41, together forming a first constraint space that restricts the axial movement of the first bearing 41. The second step 3212 and the second convex rib 3112 are staggered in the axial direction, and they are opposite each other in the radial direction of the assembly groove 321, with a distance adapted to the thickness of the second bearing 42, together forming a second constraint space that restricts the axial movement of the second bearing 42.

[0057] During fan rotation, the upward axial force on the first bearing 41 and the second bearing 42 is blocked by their respective steps and protrusions, preventing axial movement and maintaining a fixed position for rolling. This design not only avoids loosening and abnormal noise caused by bearing movement, ensuring stable rolling support, but also guarantees the stability and reliability of fan rotation.

[0058] Although the axial movement of the bearing is effectively limited by the constraint space of the steps and protrusions, the radial wobble of the mounting column 311 when the fan rotates will cause the bearing to be subjected to radial force synchronously. If there is no radial limit, the bearing is prone to deviate from the preset axis, resulting in a larger fit clearance with the mounting groove 321 and the mounting column 311, which will aggravate wear and noise.

[0059] Therefore, a plurality of constraint members 3213 are provided at the connection between the second step 3212 and the inner wall of the assembly groove 321. The constraint members 3213 extend axially along the assembly groove 321 and cover the axial range of the second bearing 42, and protrude radially inward along the assembly groove 321 with their inner ends fitting the outer circumferential surface of the outer ring of the second bearing 42. This design limits the second bearing 42 radially, and the plurality of constraint members 3213 are evenly distributed circumferentially to form an all-round radial constraint. The plurality of constraint members 3213 are evenly spaced circumferentially along the inner wall of the assembly groove 321. When the fan rotates, the outer ring of the second bearing 42 is radially restricted by the constraint members 3213 and cannot be offset radially, ensuring that the outer ring of the bearing is always stably fitted with the groove wall of the assembly groove 321, and the inner ring of the bearing rotates synchronously with the outer surface of the assembly column 311. Therefore, the radial movement of the second bearing 42 is effectively limited, ensuring the radial positioning accuracy of the second bearing 42. This improves the coaxiality and stability of the fan during rotation and avoids increased bearing wear and abnormal noise caused by radial movement.

[0060] Furthermore, after the axial and radial runout of the bearing is resolved, when the fan is running at high speed, the reaction force generated by the airflow from the fan blades will cause the upper body 31 to exert an upward attraction relative to the lower body 32. The higher the speed, the greater the attraction, which may cause the upper body 31 to shift upward or even detach from the lower body 32, leading to the risk of fan disintegration.

[0061] In this regard, the portable fan includes a stop ring 6, and the mounting post 311 is provided with an annular groove 3113 extending circumferentially thereon. The stop ring 6 is embedded in the annular groove 3113 and partially protrudes from the outer peripheral surface of the mounting post 311. The stop ring 6 and the second protruding ridge 3112 overlap at least partially in the radial direction.

[0062] When the fan rotates and generates an upward force, the mounting post 311 tends to pull the upper seat 31 upward. At this time, the lower surface of the second protrusion 3112 is limited in the upward direction by the annular stop member. The stop ring member 6 cannot pass through the second protrusion 3112 and continue to move upward, thereby constraining the bottom of the mounting post 311 to the bottom of the mounting groove 321 and blocking the path of the mounting post 311 to detach upward.

[0063] Furthermore, the mounting column 311 is a hollow column. While ensuring structural strength meets support requirements, it significantly reduces material usage and component weight; simultaneously, the hollow structure creates internal channels that can be used to run wiring and other components. When the fan rotates, the reduced weight does not affect rotational performance; on the contrary, the reduced weight decreases the drive load on the motor 51, indirectly improving the motor 51's endurance. This design reduces the weight of the fan base assembly 3, making the overall product lighter and easier for users to carry.

[0064] After optimizing the structural stability and lightweighting of the base assembly, in order to realize the function of automatic rotation and air delivery of the fan body 1, this solution also includes a rotating component 5 that drives the upper base 31 to rotate relative to the lower base 32.

[0065] like Figure 5 As shown, the rotating assembly 5 includes a motor 51 fixedly connected to the upper seat 31. The output shaft of the motor 51 is connected to an output gear 52, and a driven gear 53 meshes with the output gear 52. The driven gear 53 is fixedly mounted on the lower seat 32. The number of teeth of the driven gear 53 is greater than the number of teeth of the output gear 52.

[0066] When the motor 51 is powered on, it outputs power and drives the output gear 52 to rotate. The output gear 52 drives the driven gear 53 to rotate through meshing. Since the driven gear 53 is fixed to the lower body 32, the lower body 32 rotates relative to the upper body 31, thereby driving the body 2 and the fan body 1 to rotate, realizing automatic rotation and air delivery.

[0067] Furthermore, the driven gear 53 has a greater number of teeth than the output gear 52. It should be understood that because the output shaft of the motor 51 rotates at a relatively high speed, the output gear 52 connected to the output shaft also rotates at a relatively high speed. Therefore, setting the number of teeth of the driven gear 53, which meshes with the output gear 52, to be greater than the number of teeth of the output gear 52 increases the output torque of the output shaft, thereby reducing the rotational speed of the output shaft. This allows the lower body 32 and the upper body 31 to rotate at a suitable low speed, avoiding the shaking and noise caused by high-speed rotation.

[0068] In summary, this application addresses the pain points of high friction and noise in existing portable fan rotating structures. By utilizing the pre-reserved gap between the mounting post and the assembly slot 321, and the cooperation of the bearing assembly 4, sliding friction is converted into rolling friction, effectively reducing friction issues. Furthermore, the load is distributed by axially spaced dual bearings, and axial constraints via steps and ridges, along with radial limiting by constraint member 3213, prevent axial and radial movement of the bearings, reducing mechanical wear and abnormal noise at the source. Additionally, dual-bearing two-point support ensures rotational coaxiality, dual bearing limiting maintains fitting accuracy, and the radial overlap of the stop ring 6 and the second convex ridge 3112 prevents the upper body 31 from detaching at high speeds. This technical solution ensures that the fan body 1 does not vibrate or generate noise during rotation, improving the user experience.

[0069] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0070] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this 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.

[0071] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0072] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0073] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0074] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. The illustrative expressions of the above terms in this specification should not be construed as necessarily referring to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0075] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Since these modifications and variations fall within the scope of the claims and their equivalents, this application also intends to include these modifications and variations.

[0076] The above description describes specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A portable fan, characterized in that, include: The body of the unit is equipped with the main fan body; A fan base assembly, comprising a lower base and an upper base sleeved on the lower base, the upper base being connected to the body; The lower seat has an assembly groove that protrudes toward the upper seat; The upper seat has an assembly column that extends axially toward the lower seat. The assembly column extends into the assembly groove along the axial direction of the assembly groove, and a preset gap is left between the outer circumferential surface of the assembly column and the inner wall of the assembly groove, and a bearing assembly is assembled in the preset gap.

2. A portable fan according to claim 1, characterized in that: The bearing assembly includes a first bearing and a second bearing; The outer walls of both the first bearing and the second bearing are in contact with the groove wall of the assembly groove, and the inner walls of both the first bearing and the second bearing are in contact with the outer surface of the assembly column.

3. A portable fan according to claim 2, characterized in that: The first bearing and the second bearing are arranged at an axial distance along the assembly groove.

4. A portable fan according to claim 2, characterized in that: The inner side of the assembly groove is provided with a first step and a second step arranged at intervals along the axial direction of the assembly groove, and both the first step and the second step protrude inward along the radial direction of the assembly groove. The outer periphery of the assembly column is provided with a first protruding ridge and a second protruding ridge arranged at intervals along the axial direction, and both the first protruding ridge and the second protruding ridge extend outward along the radial direction of the assembly column. The first step and the first protruding ridge are staggered in the axial direction, and they are opposite each other in the radial direction of the assembly groove and the distance between them is adapted to the thickness of the first bearing, together forming a first constraint space that restricts the axial movement of the first bearing. The second step and the second protrusion are staggered in the axial direction, and they are radially opposite each other along the assembly groove and the distance between them is adapted to the thickness of the second bearing, together forming a second constraint space that restricts the axial movement of the second bearing.

5. A portable fan according to claim 4, characterized in that: Several constraint members are provided at the connection between the second step and the inner wall of the assembly groove; The constraint member extends axially along the assembly groove and covers the axial range of the second bearing, protrudes radially inward along the assembly groove and its inner end is adapted to the outer circumferential surface of the outer ring of the second bearing, and a plurality of the constraint members are evenly spaced along the inner wall of the assembly groove.

6. A portable fan according to claim 4, characterized in that: Includes a stop ring component, wherein the assembly post is provided with an annular groove extending circumferentially thereon, and the stop ring component is embedded in the annular groove and partially protrudes from the outer circumferential surface of the assembly post; The stop ring and the second convex ridge overlap in at least a portion of their radial direction.

7. A portable fan according to claim 1, characterized in that: The assembly column is a hollow column.

8. A portable fan according to any one of claims 1-7, characterized in that: The device includes a rotating assembly, which includes a motor fixedly connected to the upper body, an output gear connected to the output shaft of the motor, and a driven gear meshing with the output gear, the driven gear being fixedly mounted on the lower body.

9. A portable fan according to claim 8, characterized in that: The number of teeth on the driven gear is greater than the number of teeth on the output gear.

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