Fan assembly and 3D printing equipment

Abstract

The draught fan assembly comprises a mounting base, a draught fan and a connecting piece, the connecting piece is provided with a positioning structure, and the positioning structure is used for being matched with the mounting base and the draught fan so as to fix the draught fan and the mounting base to each other; and the connecting piece is made of an elastic material. According to the fan assembly, the connecting piece for connecting the fan and the mounting base is made of the elastic material, so that a flexible buffer structure is formed between the fan and the mounting base, vibration energy transmitted to the mounting base by the fan is attenuated, the influence of fan vibration on the mounting base is reduced, and the running quietness of the fan assembly is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of 3D printing, in particular to a fan assembly and a 3D printing device. BACKGROUND

[0002] As a kind of rapid prototyping technology, 3D printing technology has shown great application potential in many fields in recent years. To ensure the printing effect of 3D printing device, fan assembly is usually configured in 3D printing device.

[0003] The fan assembly is used to form an air flow path inside the 3D printing device to drive the air flow to circulate in the 3D printing device or exhaust the exhaust gas outside the 3D printing device.

[0004] The fan assembly includes a fan and a mounting seat for mounting the fan. During operation of the fan, vibration of the fan is transmitted to the entire mounting seat through the connection between the fan and the mounting seat, which causes resonance of the mounting seat and its surrounding components and generates noise. UTILITY MODEL CONTENT

[0005] The purpose of the present application is to provide a fan assembly and a 3D printing device, which aims to solve the problem of large vibration noise of the fan in the related art.

[0006] To achieve the purpose of the present application, in a first aspect, the present application provides a fan assembly, which comprises a mounting seat, a fan and a connecting piece, the connecting piece is provided with a positioning structure, the positioning structure is used to cooperate with the mounting seat and the fan to fix the fan and the mounting seat to each other.

[0007] The connecting piece is made of elastic material.

[0008] In a possible implementation, the mounting seat is provided with a positioning hole, the fan is provided with a mounting through hole, and the positioning hole and the mounting through hole are aligned with each other.

[0009] The positioning structure comprises a connecting shaft and a first shaft ring, and the connecting shaft is arranged in the positioning hole and the mounting through hole.

[0010] The first shaft ring is arranged on the side of the mounting through hole away from the mounting seat, and the cross-sectional area of the first shaft ring gradually decreases in the direction from the mounting seat to the fan.

[0011] In a possible implementation, the first shaft ring is arranged in a conical surface, and the cross-sectional area of the conical surface gradually decreases in the direction from the mounting seat to the fan, wherein the large end of the conical surface of the first shaft ring is in contact with the side of the fan away from the mounting seat.

[0012] In a possible implementation, the positioning structure further comprises a second collar, which is connected to one end of the connecting shaft away from the first collar and contacts the mounting base on a side away from the fan.

[0013] In a possible implementation, the mounting base is provided with a positioning hole, and the fan is provided with a mounting through hole, which are aligned with each other.

[0014] The positioning structure comprises a connecting shaft, a first collar and a second collar, the connecting shaft is arranged in the positioning hole and the mounting through hole, the first collar contacts the mounting base on a side away from the fan, and the second collar contacts the fan on a side away from the mounting base.

[0015] In a possible implementation, one of the mounting base and the fan is provided with a fixing member.

[0016] The fixing member is provided with a fixing space, which is aligned with the positioning hole and the mounting through hole, and the size of the fixing space is greater than the hole diameter of the positioning hole or the mounting through hole; and the second collar is arranged in the fixing space.

[0017] The second collar has an axial diameter greater than the hole diameter of the positioning hole or the mounting through hole, and the connecting shaft is adapted to the hole diameter of the positioning hole or the mounting through hole.

[0018] In a possible implementation, the outer edge surface of the fixing member is provided with a notch, which is in communication with the fixing space.

[0019] In a possible implementation, the fan assembly comprises a plurality of connecting members, and the mounting base or the fan is provided with a plurality of fixing members, the connecting members and the fixing members are arranged one by one.

[0020] The outer edge surface of each fixing member is provided with the notch, and the openings of the notches of at least two fixing members are arranged in different directions.

[0021] In a possible implementation, the connecting member further comprises a terminal shaft, which is arranged on a side of the first collar away from the connecting shaft, and the length A of the terminal shaft satisfies the relationship: 5mm≤A≤30mm.

[0022] In a possible implementation, the connecting member further comprises a third collar, which is connected to the connecting shaft, and the third collar has a first end surface and a second end surface arranged in opposite directions along the axial direction of the connecting member.

[0023] The first end surface contacts a side of the fan facing the mounting seat, and the second end surface contacts a side of the fan facing the mounting seat.

[0024] In a possible implementation, the fan assembly further comprises a shock-absorbing sleeve, which is at least partially sleeved on the fan along an outer periphery of the fan.

[0025] The shock-absorbing sleeve is filled between the fan and the mounting seat.

[0026] In a second aspect, the present application further provides a 3D printing device, which comprises a fan assembly, the fan assembly comprising a mounting seat, a fan, and a connecting piece, the connecting piece being provided with a positioning structure, the positioning structure being used to cooperate with the mounting seat and the fan to fix the fan and the mounting seat to each other.

[0027] The connecting piece is made of elastic material.

[0028] The present application forms a flexible buffering structure between the fan and the mounting seat by making the connecting piece connecting the fan and the mounting seat made of elastic material, thereby attenuating the vibration energy transmitted from the fan to the mounting seat, reducing the influence of the fan vibration on the mounting seat, and improving the quietness of the operation of the fan assembly. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort.

[0030] Figure 1 A structural schematic diagram of an embodiment of the 3D printing device provided by the present application;

[0031] Figure 2 An assembly schematic diagram of an embodiment of the connection between the fan and the mounting seat; Figure 1

[0032] An assembly schematic diagram of another embodiment of the connection between the fan and the mounting seat; Figure 3 Figure 2 An enlarged view of a part at A;

[0033] Figure 4 An enlarged view of a part at B; Figure 1

[0034] An enlarged view of a part at B; Figure 5 Figure 4

[0035] ​​​Figure 6 Fig. 1 is a structural schematic diagram of a fan assembly according to an embodiment of the present application; Figure 2 Fig. 2 is a structural schematic diagram of a connecting piece according to an embodiment of the present application;

[0036] Figure 7 Fig. 3 is a structural schematic diagram of a mounting seat according to an embodiment of the present application; Figure 2 Fig. 4 is a structural schematic diagram of a damping sleeve according to an embodiment of the present application;

[0037] Figure 8 Fig. 5 is an assembly schematic diagram of a fan, a mounting seat and a damping sleeve according to an embodiment of the present application; Figure 1

[0038] Figure 9 Figure 8 Fig. 6 is a structural schematic diagram of a damping sleeve according to an embodiment of the present application.

[0039] Legend of reference signs:

[0040] 1000 - 3D printing device;

[0041] 100 - fan assembly;

[0042] 1 - mounting seat, 11 - positioning hole, 12 - fixing piece, 121 - fixing space, 122 - notch;

[0043] 2 - fan, 21 - mounting through hole;

[0044] 3 - connecting piece, 31 - positioning structure, 311 - connecting shaft, 312 - first shaft ring, 313 - second shaft ring, 32 - third shaft ring, 33 - terminal shaft;

[0045] 4 - damping sleeve;

[0046] 200 - housing, 300 - tool head, 400 - hot bed. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0048] It should be noted that when a component is referred to as being "fixed" to another component, it can be directly on the other component or there can be a middle component. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or there can be a middle component.

[0049] ​​Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application. The use herein of "and / or" means any one of the items, but also all possible combinations of the items listed.

[0050] Some embodiments of the present application will be described in detail with reference to the drawings, where like reference numerals refer to like elements throughout. The following detailed description is not intended to limit the application, as claimed, in scope or otherwise.

[0051] Please refer to Figure 1 The present application provides a 3D printing device 1000, in some embodiments, the 3D printing device 1000 includes a housing 200, a tool head 300, a hot bed 400 and a fan assembly 100. The housing 200 is the structural body of the 3D printing device 1000, which is used to support and connect various parts of the 3D printing device 1000. The housing 200 is formed with a working cavity for 3D printing, and the hot bed 400 and the tool head 300 are movably arranged in the working cavity.

[0052] The tool head 300 is used to heat, extrude and accurately deposit the printing material on the hot bed 400 to build a three-dimensional model. In an embodiment of the present application, the tool head 300 can include a nozzle and a heating element, the heating element is used to heat the printing material to a molten state, so as to ensure that the printing material can be smoothly extruded and uniformly deposited on the hot bed 400. The extruder is used to accurately extrude the molten printing material through the nozzle, and deposit it on the hot bed 400 layer by layer according to the predetermined path to form a three-dimensional model.

[0053] The hot bed 400 has a bearing surface facing the tool head 300, which is used to support and heat the material model extruded by the tool head 300, thereby enhancing the adhesion of the first layer of material and providing a stable foundation for subsequent printing. At the same time, the hot bed 400 can also slow down the cooling speed of the printed model, reduce the stress caused by temperature gradient in the printed model, and reduce the risk of deformation of the printed model.

[0054] The fan assembly 100 is used to form an air flow path inside the 3D printing device 1000 to drive the air flow to circulate in the working cavity, so as to cooperate with the heating element in the 3D printing device 1000 to heat the working cavity, or to exhaust the high temperature and waste generated during the printing process of the 3D printing device 1000 to maintain the normal operation of the 3D printing device 1000.

[0055] Please refer to Figure 2In some embodiments, the fan assembly 100 comprises a mounting base 1, a fan 2, and a connecting piece 3, the mounting base 1 serves as the main mechanism of the fan assembly 100, and is used to support and connect various parts of the fan assembly 100.

[0056] The fan 2 is fixedly connected to the mounting base 1 through the connecting piece 3. The fan 2 can drive the air flow to circulate in the 3D printing device 1000 or discharge the air flow in the 3D printing device 1000 outside the working cavity by rotating the fan blades to form an air flow path inside the 3D printing device 1000. The fan 2 can be a centrifugal fan 2 or an axial fan 2, and the present application does not limit this. In some embodiments, the fan 2 adopts an axial fan 2, which has a larger exhaust capacity under the same size or power compared with other fans 2, and can effectively improve the driving effect of the fan 2 on the air flow in the working cavity.

[0057] During operation of the fan 2, the rotation of the fan blades of the fan 2 will cause the fan 2 to vibrate, and the vibration will be transmitted to the mounting base 1 through the connecting piece 3, thereby causing the mounting base 1 and other components mounted on the mounting base 1 to resonate and produce noise. In some embodiments, as a consumer-level 3D printer, it is often placed in a residential environment, and the printing noise will have a greater impact on the living environment.

[0058] To solve the above problems, in the present application, the connecting piece 3 is made of an elastic material, which can be rubber, silicone, polyurethane or other materials with good elasticity and shock absorption performance, and the present application does not limit this. By setting the connecting piece 3 connecting the fan 2 and the mounting base 1 to be made of an elastic material, a flexible buffer structure is formed between the fan 2 and the mounting base 1, thereby attenuating the vibration energy transmitted from the fan 2 to the mounting base 1, reducing the influence of the fan 2 vibration on the mounting base 1, and improving the quietness of the fan assembly 100 operation.

[0059] For reference Figure 3 To realize the installation of the fan 2 on the mounting base 1, the connecting piece 3 can adopt a threaded structure or a buckle structure, and the present application does not limit this. In some embodiments, the connecting piece 3 comprises a mounting base 1 provided with a positioning hole 11, and the fan 2 is provided with a mounting through hole 21, and the positioning hole 11 and the mounting through hole 21 are one-to-one corresponding and aligned with each other. The number of positioning holes 11 and mounting through holes 21 can be one or more, and the present application does not limit this.

[0060] The positioning structure 31 comprises a connecting shaft 311, which is arranged in the positioning hole 11 and the mounting through hole 21, and the connecting shaft 311 is in interference fit with the positioning hole 11 and the mounting through hole 21, so that the fan 2 and the mounting base 1 are connected to each other.

[0061] For reference Figure 4 to Figure 6To improve the stability of the connection of the connector 3 to the fan 2 side, in some embodiments, the positioning structure further includes a first collar 312. The first collar 312 is connected to the connecting shaft 311. The first collar 312 is disposed on the side of the mounting through hole 21 away from the mounting base 1, and the cross-sectional area of ​​the first collar 312 gradually decreases along the direction from the mounting base 1 to the fan 2. In some embodiments, the connecting shaft 311 no longer needs to be connected to the mounting through hole 21 by an interference fit, but only needs to be adapted to the diameter of the mounting through hole 21 (i.e., the shaft diameter of the connecting shaft 311 can be equal to or slightly smaller than the diameter of the mounting through hole 21), thereby reducing the installation difficulty of the connector 3 in the mounting through hole 21 and improving the installation efficiency of the connector 3 and the fan 2. On the other hand, the setting of the first collar 312 can also prevent the connecting shaft 311 from coming out of the mounting through hole 21, improving the stability of the connection of the connector 3 to the fan 2 side.

[0062] Compared to a snap-fit ​​structure, the structure using connecting shaft 311 and first collar 312 is simpler, and the manufacturing cost of connector 3 is lower. Compared to a threaded structure, connecting shaft 311 and first collar 312 eliminate the need for tapping threaded holes at the connection between fan 2 and mounting base 1. The connection between fan 2 and mounting base 1 does not require reserving plate thickness for tapping threaded holes in the manufacturing process, allowing for a thinner design. This reduces the thickness of fan 2 and mounting base 1, reduces the thickness of fan assembly 100, and improves the space utilization of fan assembly 100 within the 3D printing equipment 1000.

[0063] In some embodiments, the first collar 312 is provided with a conical surface, and the cross-sectional area of ​​the conical surface gradually decreases along the direction from the mounting base 1 to the fan 2. This reduces the resistance of the connector 3 when it is inserted into the positioning hole 11 and the mounting through hole 21 from the mounting base 1 to the fan 2, reduces the assembly difficulty of the connector 3 with the fan 2 and the mounting base 1, and improves the assembly efficiency of the connector 3, the fan 2 and the mounting base 1.

[0064] In some embodiments, the large end of the tapered surface of the first collar 312 contacts the side of the fan 2 away from the mounting base 1, thereby reducing the activity space of the fan 2 on the side away from the mounting base 1, reducing the installation gap between the fan 2 and the mounting base 1, and improving the stability of the connection between the fan 2 and the mounting base 1.

[0065] To improve the stability of the connection of the connector 3 on the mounting base 1 side, in some embodiments, the positioning structure 31 further includes a second collar 313. The second collar 313 is connected to the end of the connecting shaft 311 opposite to the first collar 312, and the second collar 313 contacts the side of the mounting base 1 opposite to the fan 2. The shaft diameter of the second collar 313 is larger than the diameter of the positioning hole 11 or the mounting through hole 21. With this configuration, in some embodiments, the connecting shaft 311 no longer needs to be connected to the positioning hole 11 through an interference fit, but only needs to be adapted to the diameter of the positioning hole 11 (i.e., the shaft diameter of the connecting shaft 311 can be equal to or slightly smaller than the diameter of the positioning hole 11), thereby reducing the installation difficulty of the connector 3 in the positioning hole 11 and improving the installation efficiency of the connector 3 and the mounting base 1. On the other hand, the second collar 313 can also reduce the possibility of the connecting shaft 311 coming out of the positioning hole 11, improving the stability of the connection of the connector 3 on the mounting base 1 side.

[0066] Understandably, in some other embodiments, while the connecting shaft 311 is interference-fitted with the positioning hole 11, a second collar 313 may be used to reduce the possibility of the connecting shaft 311 coming out of the positioning hole 11 and improve the stability of the connection of the connector 3 on the mounting base 1 side.

[0067] Please refer to Figure 5 and Figure 7 In some embodiments, the mounting base 1 is provided with fixing members 12, the number of which corresponds one-to-one with the number of positioning holes 11 and mounting through holes 21. Each fixing member 12 has a fixing space 121, which is aligned with the positioning holes 11 and mounting through holes 21. The size of the fixing space 121 is larger than the diameter of the positioning holes 11 or mounting through holes 21. A second collar 313 is disposed within the fixing space 121. This increases the contact area between the second collar 313 and the mounting base 1, improving the stability of the connection of the connector 3 on one side of the mounting base 1.

[0068] In some embodiments, the aperture of the fixing space 121 is slightly larger than the ring diameter of the second collar 313, and the second collar 313 is interference-fitted into the fixing space 121. This prevents the second collar 313 from coming out of the fixing space 121 and improves the stability of the connector 3 within the fixing space 121. To facilitate the installation of the second collar 313 within the fixing space 121, the fixing member 12 is also provided with a notch 122, which communicates with the fixing space 121. In actual operation, the assembler can use compression to cause the second collar 313 to undergo elastic deformation and enter the notch 122, and then enter the fixing space 121 through the notch 122, thereby completing the installation of the second collar 313 within the fixing space 121. Compared with other installation methods, the notch 122 effectively reduces the resistance of the second collar 313 entering the fixing space 121, reduces the installation difficulty of the connector 3 and the mounting base 1, and improves the installation efficiency of the connector 3 and the mounting base 1.

[0069] Understandably, while the notch 122 improves the installation efficiency of the connector 3 and the mounting base 1, if the fan 2 vibrates along the opening direction of the notch 122, the second collar 313 may also detach from the fixed space 121 along the direction of the notch 122. To solve this problem, in some embodiments, the mounting base 1 or the fan 2 is provided with multiple fasteners 12, and the connector 3 is provided in a one-to-one correspondence with each fastener 12. The outer edge of each fastener 12 is provided with the notch 122, and at least two of the fasteners 12 have different opening orientations for their notches 122. This prevents all second collars 313 from detaching from the notch 122 when the fan vibrates along a certain notch 122 direction, increases the possibility of the connector 3 detaching from the fixed space, and improves the stability of the installation of the connector 3 and the fastener 12.

[0070] Please refer to Figure 3 and Figure 5 In some embodiments, the connector 3 further includes a third collar 32, which is connected to the connecting shaft 311. The third collar 32 has a first end face and a second end face that are opposite to each other along the axial direction of the connector 3. The first end face contacts the side of the mounting base 1 facing the fan 2, and the second end face contacts the side of the fan 2 facing the mounting base 1. This creates a buffer between the fan 2 and the mounting base 1, thereby attenuating the vibration energy transmitted from the fan 2 to the mounting base 1, reducing the impact of the fan 2's vibration on the mounting base 1, and improving the quietness of the fan assembly 100 operation.

[0071] In some embodiments, the connector 3 further includes an end shaft 33, which is located on the side of the first collar 312 facing away from the connecting shaft 311. The length of the end shaft 33 is A, satisfying the relationship: 5mm≤A≤30mm. The end shaft 33 is used to provide leverage for the installation of the connector 3 in the positioning hole 11 and the mounting through hole 21. The operator can first pass the end shaft 33 through the positioning hole 11 and the mounting through hole 21, and then pull the first collar 312 through the positioning hole 11 and the mounting through hole 21 by holding the end shaft 33, thereby realizing the connection of the connector 3, the mounting base 1 and the fan 2, reducing the installation difficulty of the connector 3, the mounting base 1 and the fan 2, and improving the installation efficiency of the connector 3, the mounting base 1 and the fan 2.

[0072] In some embodiments, besides using the mounting base as the mounting reference to mount the fan, the fan can also be used as the mounting reference to mount the mounting base onto the fan. In this case, the positioning structure includes a connecting shaft, a first collar, and a second collar. The connecting shaft passes through a positioning hole and a mounting through hole. The first collar contacts the side of the mounting base away from the fan, thus mounting the mounting base onto the fan. Simultaneously, the second collar contacts the side of the fan away from the mounting base, thereby preventing the connecting shaft from dislodging from the mounting through hole and improving the stability of the connection between the connector and the mounting base and the fan.

[0073] In conjunction with the above embodiments, to improve the installation efficiency of the connector, fan, and mounting base, in some embodiments, the first collar is tapered, and the cross-sectional area of ​​the tapered surface gradually decreases along the direction from the fan to the mounting base. This reduces the resistance of the connector when inserted into the positioning hole and mounting through hole from the fan to the mounting base, lowers the assembly difficulty of the connector with the fan and mounting base, and improves the assembly efficiency of the connector, fan, and mounting base.

[0074] In embodiments where the mounting base serves as the installation reference, to improve the stability of the connection between the connector and the fan, in some embodiments, the fan is equipped with fixing components, the number of which corresponds one-to-one with the number of positioning holes and mounting through holes. Each fixing component has a fixing space aligned with the positioning holes and mounting through holes, and the size of the fixing space is larger than the diameter of the positioning holes or mounting through holes; a second collar is disposed within the fixing space. This increases the contact area between the second collar and the mounting base, improving the stability of the connection between the connector and the mounting base.

[0075] The fixing components on the fan can also have notches, which connect to the fixing space. During actual operation, the assembler can use compression to cause the second shaft collar to elastically deform and enter the notch, then through the notch into the fixing space, thus completing the installation of the second shaft collar within the fixing space. Compared to other installation methods, the notch effectively reduces the resistance to the second shaft collar entering the fixing space, reduces the installation difficulty of the connectors and the fan, and improves the installation efficiency of the connectors and the fan.

[0076] In some embodiments, multiple fasteners may be provided on the fan, and at least two of the fasteners may have notches with different opening orientations. This is to prevent all second collars from dislodging from the notches when the fan vibrates along a certain notch direction, thereby increasing the possibility of the connectors dislodging from the fixed space and improving the stability of the connector and fastener installation.

[0077] Please refer to Figure 8 and Figure 9 In some embodiments, the fan assembly 100 further includes a shock-absorbing sleeve 4, which is at least partially fitted around the outer periphery of the fan; the shock-absorbing sleeve 4 fills the space between the fan 2 and the mounting base 1. The material of the shock-absorbing sleeve 4 can be rubber, elastic silicone, or polyurethane, and this application does not limit this. The shock-absorbing sleeve 4 is used to form a buffer between the fan 2 and the mounting base 1, thereby further attenuating the vibration energy transmitted from the fan 2 to the mounting base 1, reducing the impact of the fan 2 vibration on the mounting base 1, and improving the quietness of the fan assembly 100 operation.

[0078] In the description of the embodiments of this application, it should be noted that the orientation or positional relationship of the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and other indicators are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0079] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art will understand that all or part of the processes for implementing the above embodiments and equivalent variations made in accordance with the claims of this application are still within the scope of this application.

Claims

1. A fan assembly comprising: The fan assembly comprises a mounting base, a fan and a connecting piece, the connecting piece is provided with a positioning structure, the positioning structure is used for cooperating with the mounting base and the fan to fix the fan and the mounting base to each other. The connecting piece is made of elastic material.

2. The fan assembly of claim 1, wherein, The mounting base is provided with a positioning hole, the fan is provided with a mounting through hole, the positioning hole and the mounting through hole are aligned with each other. The positioning structure comprises a connecting shaft and a first shaft ring, the connecting shaft is arranged in the positioning hole and the mounting through hole. The first shaft ring is arranged on the side of the mounting through hole away from the mounting base, and the cross-sectional area of the first shaft ring gradually decreases along the direction from the mounting base to the fan.

3. The fan assembly of claim 2, wherein, The first shaft ring is arranged in a conical surface, and the cross-sectional area of the conical surface gradually decreases along the direction from the mounting base to the fan, wherein the large end of the conical surface of the first shaft ring is in contact with the side of the fan away from the mounting base.

4. The fan assembly of claim 2, wherein, The positioning structure further comprises a second shaft ring, the second shaft ring is connected with the end of the connecting shaft away from the first shaft ring, and the second shaft ring is in contact with the side of the mounting base away from the fan.

5. The fan assembly of claim 1, wherein, The mounting base is provided with a positioning hole, the fan is provided with a mounting through hole, the positioning hole and the mounting through hole are aligned with each other. The positioning structure comprises a connecting shaft, a first shaft ring and a second shaft ring, the connecting shaft is arranged in the positioning hole and the mounting through hole, the first shaft ring is in contact with the side of the mounting base away from the fan, and the second shaft ring is in contact with the side of the fan away from the mounting base.

6. A fan assembly as claimed in any one of claims 4 or 5, wherein, One of the mounting base and the fan is provided with a fixing piece. The fixing piece is provided with a fixing space, the fixing space is aligned with the positioning hole and the mounting through hole, the size of the fixing space is greater than the hole diameter of the positioning hole or the mounting through hole, and the second shaft ring is arranged in the fixing space. The shaft diameter of the second shaft ring is greater than the hole diameter of the positioning hole or the mounting through hole, and the connecting shaft is matched with the hole diameter of the positioning hole or the mounting through hole.

7. The fan assembly of claim 6, wherein, The outer edge surface of the fixing piece is provided with a notch, and the notch is communicated with the fixing space.

8. The fan assembly of claim 7, wherein, The fan assembly comprises a plurality of connecting pieces, the mounting base or the fan is provided with a plurality of fixing pieces, and the connecting pieces and the fixing pieces are one-to-one corresponding. The outer edge surface of each fixing piece is provided with the notch, and the openings of the notches of at least two fixing pieces are arranged in different directions.

9. The fan assembly of claim 2 or 5, wherein, The connecting piece further comprises a terminal shaft, the terminal shaft is arranged on the side of the first shaft ring away from the connecting shaft, and the length A of the terminal shaft satisfies the relationship: 5mm≤A≤30mm.

10. The fan assembly of claim 2, wherein, The connecting piece further comprises a third shaft ring, the third shaft ring is connected with the connecting shaft, and the third shaft ring has a first end surface and a second end surface arranged in opposite directions along the axial direction of the connecting piece. The first end surface is in contact with the side of the mounting base facing the fan, and the second end surface is in contact with the side of the fan facing the mounting base.

11. The fan assembly of claim 1, wherein, The fan assembly further comprises a shock-absorbing sleeve, the shock-absorbing sleeve is at least partially arranged on the outer periphery of the fan. The shock-absorbing sleeve is at least partially filled between the fan and the mounting base.

12. A 3D printing device, characterized by A fan assembly comprising any one of claims 1-11.

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