Fan

Abstract

The embodiment of the invention provides a fan which comprises an impeller, a fan blade and a fan blade. A first housing accommodating the impeller; the second shell is arranged on one axial side of the first shell and is matched with the first shell; a motor disposed on one side of the impeller in the axial direction and housed in the second housing; a rotating shaft which is attached to the impeller, is driven by the motor, and rotates together with the impeller; and a bearing disposed on the outer periphery of the rotating shaft and supporting the rotating shaft. Wherein a pre-pressing part and a pre-pressing supporting part which are in contact with each other in the axial direction are arranged between one axial side of the impeller and the other axial side of the bearing, the pre-pressing part and the pre-pressing supporting part are made of different materials, and the pre-pressing part or the pre-pressing supporting part is in contact with the bearing. According to the fan, the pre-pressure applied to the bearing can be increased in the axial direction, and in addition, the noise of the fan can be reduced.

Description

Technical Field

[0001] The present application relates to the field of electromechanical technology, and in particular to a fan. Background Art

[0002] With the development of science and technology, fans have been used in a variety of environments. In the conventional design of a fan, an impeller and a rotating shaft are arranged in the axial direction of the fan, and a bearing is arranged on the outer periphery of the rotating shaft. Driven by a motor, the rotating shaft rotates together with the impeller.

[0003] Sometimes, a spring component is provided between the impeller and the bearing, and the spring component can provide pre-pressure for the bearing, thereby facilitating the operation of the bearing.

[0004] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of the present application and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because they are described in the background technology section of the present application. Summary of the invention

[0005] The inventors found that: in the existing structure, since the spring component and the bearing are both made of metal, when the spring is clamped between the impeller and the bearing, the spring component and the bearing will collide and / or rub as the spring component rotates with the impeller, so that the preload applied by the spring component on the bearing may be reduced, affecting the normal operation of the bearing. In addition, the collision and / or friction between the spring component and the bearing will also generate noise.

[0006] In order to solve at least one of the above problems or other similar problems, an embodiment of the present application provides a fan. A pre-stressing component and a pre-stressing support component are provided between one axial side of the impeller and the other axial side of the bearing, which are in contact with each other in the axial direction and made of different materials, thereby increasing the pre-stressing force applied to the bearing in the axial direction. In addition, the pre-stressing component is isolated from the bearing in the axial direction by the pre-stressing support component, which can reduce the noise of the fan.

[0007] According to one aspect of an embodiment of the present application, a wind turbine is provided, the wind turbine comprising:

[0008] an impeller, which rotates about a central axis;

[0009] a first housing accommodating the impeller;

[0010] A second housing, which is disposed on one axial side of the first housing and is installed in cooperation with the first housing;

[0011] a motor, which is arranged on one axial side of the impeller and accommodated in the second housing;

[0012] a rotating shaft mounted on the impeller, driven by the motor, and rotating together with the impeller; and

[0013] A bearing is arranged on the outer periphery of the rotating shaft to support the rotating shaft; wherein,

[0014] A preload component and a preload support component are provided between one axial side of the impeller and the other axial side of the bearing. The preload component and the preload support component are made of different materials and are in contact with the bearing.

[0015] In some embodiments, the material of the pre-stressing component is metal, and the material of the pre-stressing supporting component is resin.

[0016] In some embodiments, the pre-stressing support component is disposed on one axial side of the pre-stressing component and is in contact with the bearing; and / or

[0017] The preload support member is provided on the other axial side of the preload member and is in contact with the impeller or an impeller frame for supporting the impeller.

[0018] In some embodiments, the pre-stress support component has a cover portion, an axial end surface of the cover portion is in contact with the pre-stress component, and a radial inner periphery of the cover portion is interference-fitted with an outer periphery of the rotating shaft.

[0019] In some embodiments, the pre-pressing support component further comprises a wall portion, wherein the wall portion is formed to extend from the outer periphery of the cover portion in the axial direction toward the pre-pressing component, and the wall portion covers at least a portion of a radial outer surface of the pre-pressing component.

[0020] In some embodiments, the wall portion and at least one of the cover portions have a gap in the axial direction, or

[0021] The wall portion is provided as a first wall portion and a second wall portion in the axial direction, and a gap is provided between the first wall portion and the second wall portion in the axial direction.

[0022] In some embodiments, the pre-stressing component is a metal spring, and the size of the gap is smaller than or equal to the wire diameter of the spring.

[0023] In some embodiments, the radial inner peripheral surface of the wall portion has textures that cooperate with the pre-pressing component.

[0024] In some embodiments, the material of the pre-stress component is rubber, and the material of the pre-stress support component is metal.

[0025] In some embodiments, the pre-stressed support component is a sleeve disposed on the outer circumference of the rotating shaft, and the sleeve forms an interference fit with the rotating shaft.

[0026] In some embodiments, the pre-stressing component is disposed on at least one axial end surface of the pre-stressing supporting component.

[0027] In some embodiments, a radial dimension of the pre-stressing support component is larger than a radial dimension of the pre-stressing component.

[0028] In some embodiments, an impeller frame is provided between the rotating shaft and the impeller, and a radial inner surface of an axial end portion of the impeller frame abuts against a radial outer surface of the sleeve.

[0029] In some embodiments, an inner circumference of the first housing close to the impeller is step-free.

[0030] One of the beneficial effects of the embodiments of the present application is that a prestressing component and a prestressing support component which are in axial contact with each other and made of different materials are arranged between one axial side of the impeller and the other axial side of the bearing, thereby increasing the prestressing force applied to the bearing in the axial direction; in addition, the prestressing component is isolated from the bearing in the axial direction by the prestressing support component, thereby reducing the noise of the fan.

[0031] With reference to the following description and accompanying drawings, the embodiments of the present application are disclosed in detail. It should be understood that the embodiments of the present application are not limited in scope. Within the spirit and scope of the appended claims, the embodiments of the present application include many changes, modifications and equivalents.

[0032] Features described and / or illustrated with respect to one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.

[0033] It should be emphasized that the terms “include / comprises / has” when used herein refer to the existence of a feature, an integer, or a component, but do not exclude the existence or addition of one or more other features, integers, or components. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The above and other objects, features and advantages of the embodiments of the present application will become more apparent from the following detailed description in conjunction with the accompanying drawings, in which:

[0035] Figure 1 is a three-dimensional schematic diagram of a fan according to an embodiment of the present application;

[0036] Figure 2 is an axial cross-sectional view of an example of a fan according to an embodiment of the present application;

[0037] Figure 3 is a schematic diagram of a pre-pressing component and a pre-pressing supporting component in an embodiment of the present application;

[0038] Figure 4 is another schematic diagram of a pre-pressing component and a pre-pressing supporting component in an embodiment of the present application;

[0039] Figure 5 is a schematic diagram of a pre-compression support component according to an embodiment of the present application;

[0040] Figure 6 is an axial cross-sectional view of another example of a wind turbine according to an embodiment of the present application;

[0041] Figure 7 It is a top view schematic diagram of the pre-pressing component of an embodiment of the present application. DETAILED DESCRIPTION

[0042] With reference to the accompanying drawings, the above and other features of the present application will become apparent through the following description. In the description and the accompanying drawings, specific embodiments of the present application are specifically disclosed, which show some embodiments in which the principles of the present application can be adopted. It should be understood that the present application is not limited to the described embodiments. On the contrary, the present application includes all modifications, variations and equivalents falling within the scope of the attached claims.

[0043] In the embodiments of the present application, the term "and / or" includes any one and all combinations of one or more of the associated listed terms. The terms "include", "comprises", "has", etc. refer to the existence of the stated features, elements, components or components, but do not exclude the existence or addition of one or more other features, elements, components or components.

[0044] In the embodiments of the present application, the singular forms "a", "the", etc. may include plural forms and should be broadly understood as "a kind" or "a type" rather than being limited to the meaning of "one"; in addition, the term "said" should be understood to include both singular and plural forms, unless the context clearly indicates otherwise. In addition, the term "according to" should be understood as "at least in part according to...", and the term "based on" should be understood as "at least in part based on...", unless the context clearly indicates otherwise.

[0045] In addition, in the following description of the present application, for the convenience of explanation, the direction extending along the central axis CC' of the fan or the direction parallel to it is referred to as "axial", the radial direction centered on the central axis is referred to as "radial", the direction around the central axis is referred to as "circumferential", the side away from the central axis in the radial direction is referred to as "radial outer side", and the side close to the central axis in the radial direction is referred to as "radial inner side". In addition, the direction from the bottom of the fan to the fan impeller is referred to as "above" or "upper side", and the direction from the impeller of the fan to the bottom of the fan is referred to as "below" or "lower side". It is worth noting that the definition of each direction in this specification is only for the convenience of explaining the embodiments of the present application, and does not limit the direction of the fan, etc. during use and manufacture.

[0046] The implementation of the embodiments of the present application will be described below with reference to the accompanying drawings.

[0047] Embodiments of the first aspect

[0048] Figure 1 is a three-dimensional schematic diagram of a fan according to an embodiment of the present application; Figure 2 is an axial cross-sectional view of an example of a fan according to an embodiment of the present application; Figure 3 is a schematic diagram of a pre-pressing component and a pre-pressing supporting component in an embodiment of the present application; Figure 4 is another schematic diagram of a pre-pressing component and a pre-pressing supporting component in an embodiment of the present application; Figure 5 It is a schematic diagram of the pre-stressed support component of an embodiment of the present application.

[0049] like Figure 1 and Figure 2 As shown, the fan 100 includes: an impeller 11, a first housing 12, a second housing 13, a rotating shaft 14, a bearing 15 and a motor 16 (see Figure 2 ).

[0050] The impeller 11 has a central axis (e.g. Figure 1 The first housing 12 accommodates the impeller 11. The second housing 13 is arranged on one axial side of the first housing 12, that is, axially below (for example, Figure 1 The first housing 12 is mounted on the C' side of the impeller 11. The motor 16 is arranged on one axial side (i.e., the C' side) of the impeller 11 and is accommodated in the second housing 13. The rotating shaft 14 is installed on the impeller 11, driven by the motor 16, and rotates together with the impeller 11. The bearing 15 is arranged on the outer periphery of the rotating shaft 14 to support the rotating shaft 14.

[0051] The above only describes the structure of the fan related to the present application. Those skilled in the art should understand that the fan may also have other structures, and reference may be made to related technologies, and the description is omitted here.

[0052] In the embodiments of the present application, Figure 2 As shown, on one axial side of the impeller 11 (for example, Figure 2 The C' side shown) and the other axial side of the bearing 15 (for example, Figure 2 A preload component 2 and a preload support component 3 are provided between the bearing 15 and the bearing 15 (shown on the C side). The preload component 2 and the preload support component 3 are made of different materials, and the preload support component 3 is in contact with the bearing 15. The preload component 2 can be in a compressed state, so that it can provide pressure to the bearing 15, which is called preload. Due to the preload support component 3, the preload applied to the bearing 15 in the axial direction by the preload component 2 is greater, which can be conducive to the stable operation of the bearing 15.

[0053] In addition, if Figure 2 As shown, the preload support component 3 isolates the preload component 2 from the bearing 15 in the axial direction (i.e., the preload support component 3 contacts the bearing 15 instead of the preload component 2 directly contacting the bearing 15), thereby avoiding the noise caused by the direct contact between the preload component 2 and the bearing 15.

[0054] In some embodiments, the pre-pressing component 2 and the pre-pressing support component 3 are made of different materials, which may be: the hardness of the materials of the pre-pressing component 2 and the pre-pressing support component 3 is different; or, the pre-pressing component 2 and the pre-pressing support component 3 are respectively made of metal material and non-metal material, for example, the material of the pre-pressing component 2 is metal, and the material of the pre-pressing support component 3 is resin. For example, the pre-pressing component 2 is a metal spring, but the present application is not limited thereto.

[0055] Thus, the preload component 2 and the bearing 15 are blocked by the preload support component 3, avoiding direct contact between the metal preload component 2 and the metal bearing 15, thereby reducing noise, eliminating metal resonance, and improving the stability of the rotation of the bearing 15.

[0056] In some embodiments, the metal spring used as the pre-stressing component 2 may be a cylindrical helical spring, and the buffering adjustment function of the spring may reduce or absorb the impact force caused by the pressure change of the impeller 11 .

[0057] like Figure 2 The prestressing support component 3 is arranged on one axial side of the prestressing component 2 and contacts the bearing 15; and / or, the prestressing support component 3 is arranged on the other axial side of the prestressing component 2 and contacts the impeller 11 or the impeller frame 4 for supporting the impeller 11.

[0058] For example, Figure 2As shown in the partially enlarged view, the spring as the preload component 2 is arranged between the impeller frame 4 and the bearing 15, and a preload support component 3-1 is arranged between one axial side of the preload component 2 and the bearing 15, and the preload support component 3-1 is in contact with the upper surface 151 of the bearing 15; and a preload support component 3-2 is arranged between the other axial side of the preload component 2 and the impeller 11, or a preload support component 3-2 is arranged between the other axial side of the preload component 2 and the impeller frame 4, and the preload support component 3-2 is in contact with the impeller 11 or the impeller frame 4.

[0059] For example, Figure 3 As shown, the preload support component 3-1 is provided only between one axial side of the preload component 2 and the bearing 15. Alternatively, the preload support component 3-2 (not shown in the figure) is provided only between the other axial side of the preload component 2 and the impeller 11 or the impeller frame 4.

[0060] In the above example, if Figure 2 As shown, the fan 100 has two pre-stress support components, namely, the pre-stress support component 3-1 and the pre-stress support component 3-2, and the two pre-stress support components are of the same structure (for example, the axial cross-sections of both are L-shaped), but the present application is not limited thereto, and the pre-stress support component 3 may be only one (such as Figure 3 As shown in FIG. 1 , when there is only one pre-stressing support component 3, the height of the pre-stressing support component 3 is greater than any one of the two pre-stressing support components 3 in the above example. The overall height of the pre-stressing support component 3 depends on the height between the bearing 15 and the impeller 11.

[0061] In some embodiments, when the number of the pre-stressing support components 3 is two (for example, the two pre-stressing support components 3 are respectively the pre-stressing support component 3 - 1 and the pre-stressing support component 3 - 2 , the two pre-stressing support components 3 may have different structures.

[0062] like Figure 4 As shown, the pre-stressing support component 3-1 and the pre-stressing support component 3-2 have different structures. Figure 4 In the embodiment, the axial section of the preload support component 3-1 is L-shaped, and the preload support component 3-2 is annular (for example, an annular gasket); in addition, the preload support component 3-1 may be annular, and the axial section of the preload support component 3-2 may be L-shaped.

[0063] In some embodiments, Figure 4 As shown, the preload support components 3 (for example, the preload support component 3 - 1 and the preload support component 3 - 2 ) each have a cover portion 31 , an axial end surface 311 of the cover portion 31 contacts the preload component 2 , and a radial inner periphery 311 of the cover portion 31 is interference fit with the outer periphery 141 of the rotating shaft 14 .

[0064] For example, the prestressing support component 3 needs to rotate together with the rotating shaft 14, and the pressure of the prestressing component 2 can push the prestressing support component 3 to move axially, so that the prestressing support component 3 (for example, the prestressing support component 3-1) contacts the surface 151 of the bearing 15. In order to meet the above requirements, the radial inner periphery 311 of the cover 31 and the outer periphery 141 of the rotating shaft 14 can be a light interference fit. For example, the interference between the two is 0 to 20 microns. However, the present application is not limited to this, and the interference can be adjusted according to actual needs.

[0065] In some embodiments, Figure 4 and Figure 5 As shown, the pre-stressed support member 3 (for example, Figure 4 The preload support member 3-1) further includes a wall portion 32. The wall portion 32 is formed by extending from the outer periphery of the cover portion 31 toward the preload member 2 in the axial direction, and the wall portion 32 covers at least a portion of the radial outer surface of the preload member 2.

[0066] As a result, deformation and displacement of the preload member 2 in the radial direction are suppressed, and the preload generated by the preload member 2 is further increased.

[0067] In some embodiments, there is a gap between the wall portion 32 and at least one cover portion 31 in the axial direction, or the wall portion 32 is provided in the axial direction with a first wall portion 321 and a second wall portion 322, and there is a gap between the first wall portion 321 and the second wall portion 322 in the axial direction. The size of the gap is less than or equal to the wire diameter of the spring.

[0068] For example, Figure 4 As shown, a gap L is provided in the axial direction between a wall portion 32 of the preload support member 3 provided on one axial side of the preload member 2 and a cover portion 31 of the preload support member 3 provided on the other axial side of the preload member 2 .

[0069] For example, Figure 2 As shown, a prestressing support component 3-1 is provided on one axial side of the prestressing component 2, and the wall portion of the prestressing support component 3-1 is a first wall portion 321. A prestressing support component 3-2 is provided on the other axial side of the prestressing component 2, and the wall portion of the prestressing support component 3-2 is a second wall portion 322. There is a gap between the first wall portion 321 and the second wall portion 322 in the axial direction.

[0070] Thus, a gap is provided in the axial direction, so that the preload member 2 and the preload support member 3 can be easily assembled, and a certain amount of compression of the spring serving as the preload member 2 is allowed.

[0071] Furthermore, the size of the gap is smaller than or equal to the wire diameter of the spring, which can provide more adequate protection for the spring serving as the preload component 2 and prevent the spring from radial displacement and deformation.

[0072] In some embodiments, the radial inner peripheral surface of the wall portion 32 has a texture that matches the pre-pressing component 2, so that the texture can facilitate the close fit between the wall portion 32 of the pre-pressing support component 3 and the pre-pressing component 2, thereby further avoiding radial deformation of the pre-pressing component 2. In addition, the inner wall of the wall portion 32 can be smooth or have a certain degree of roughness, thereby increasing the friction between the friction wall portion 32 and the pre-pressing component 2, and further improving the close fit between the wall portion 32 of the pre-pressing support component 3 and the pre-pressing component 2.

[0073] Figure 6 is a cross-sectional view of another example of a wind turbine according to an embodiment of the present application; Figure 7 yes Figure 6 A top view schematic diagram of the pre-stressing component in.

[0074] like Figure 6 and Figure 7 As shown, on one axial side of the impeller 11 (for example, Figure 6 The C' side shown) and the other axial side of the bearing 15 (for example, Figure 6 A pre-stressing component 2 and a pre-stressing support component 3 are provided between the bearing 15 and the bearing 15, and the pre-stressing component 2 and the pre-stressing support component 3 are made of different materials, and the pre-stressing component 2 is in contact with the bearing 15. For example, the pre-stressing component 2 and the pre-stressing support component 3 are made of different materials with different hardnesses; or, the pre-stressing component 2 and the pre-stressing support component 3 are made of non-metallic material and metal material respectively. For example, the material of the pre-stressing component 2 is rubber, for example, the pre-stressing component 2 is an annular rubber ring (such as Figure 7 As shown), the material of the pre-stressed supporting component 3 is metal.

[0075] In some embodiments, the pre-stressing component 2 is a rubber ring, so that the pre-stressing component 2 can directly contact the bearing 15 (for example, made of metal) without generating friction noise or other noise due to the contact between the pre-stressing component 2 and the bearing 15 .

[0076] In some embodiments, the pre-stressing support component 3 is a sleeve (e.g., a metal sleeve) disposed on the outer periphery of the rotating shaft 14, and the sleeve forms an interference fit with the rotating shaft 14. For example, the pressure of the pre-stressing component 2 can push the pre-stressing support component 3 to move axially, and the pre-stressing support component 3 and the rotating shaft 14 rotate together, for example, the interference is 0 to 20 microns, but the present application is not limited thereto, and the interference can be adjusted according to the rotation situation.

[0077] As a result, the preload force exerted on the bearing is increased by the preload support member 3 .

[0078] In some embodiments, the pre-stressing component 2 is disposed on at least one axial end surface 21 of the pre-stressing supporting component 3 .

[0079] For example, Figure 6As shown, the number of pre-stress components 2 is 2, namely, pre-stress component 2-1 and pre-stress component 2-2, wherein: the pre-stress component 2-1 is arranged between one axial side (C' side) of the pre-stress support component 3 and the other axial side (C side) of the bearing 15, and the pre-stress component 2-1 is in contact with the end face 21 of the pre-stress support component 3 and the upper surface 151 of the bearing 15 respectively; the pre-stress component 2-2 is arranged between one axial side of the impeller frame 4 and the other axial side of the pre-stress support component 3, and the pre-stress component 2-2 is in contact with the impeller frame 4 and the end face 21 of the pre-stress support component 3 respectively.

[0080] For another example, the pre-stress component 2 can be one and is only arranged between one axial side (C' side) of the pre-stress support component 3 and the other axial side (C side) of the bearing 15; or, the pre-stress component is only arranged in one and is arranged between the impeller frame 4 and the end face 21 of the pre-stress support component 3.

[0081] In some embodiments, the radial dimension of the pre-pressing support component 3 is larger than the radial dimension of the pre-pressing component 2. Thus, it can be ensured that the pre-pressing support component 3 has sufficient supporting surface to reliably support the pre-pressing component 2.

[0082] In some embodiments, Figure 6 As shown, the impeller holder 4 is provided between the rotating shaft 14 and the impeller 11 , and the radial inner surface 42 of the axially one end portion 41 of the impeller holder 4 abuts against the radial outer surface 51 of the sleeve.

[0083] As a result, the impeller carrier 4 can pre-compress the pre-compression member 2 in the radial direction, thereby further improving the pre-compression effect of the pre-compression member 2 on the bearing 15 .

[0084] In addition, in this application Figure 6 and Figure 2 In the example shown, the impeller frame 4 may be made of a metal material, or a resin or the like (for example, the same material as the impeller 11 ).

[0085] In some embodiments, the inner circumference of the first housing 12 close to the impeller 11 is step-free.

[0086] This can reduce the noise of the fan.

[0087] According to an embodiment of the first aspect, a prestressing component and a prestressing support component which are in axial contact with each other and are made of different materials are arranged between one axial side of the impeller and the other axial side of the bearing, thereby increasing the prestressing force applied to the bearing in the axial direction. In addition, the prestressing component is isolated from the bearing in the axial direction by the prestressing support component, thereby reducing the noise of the fan.

[0088] The embodiments of the present application are described above in conjunction with specific implementation methods, but it should be clear to those skilled in the art that these descriptions are exemplary and are not intended to limit the scope of protection of the embodiments of the present application. Those skilled in the art can make various modifications and variations to the embodiments of the present application based on the spirit and principles of the embodiments of the present application, and these modifications and variations are also within the scope of the embodiments of the present application.

[0089] The preferred embodiments of the present application are described above with reference to the accompanying drawings. Many features and advantages of these embodiments are clear from this detailed description, and therefore the appended claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. In addition, since many modifications and changes are easily conceivable to those skilled in the art, it is not intended to limit the embodiments of the present application to the precise structures and operations illustrated and described, but all suitable modifications and equivalents that fall within its scope may be covered.

Claims

1. A fan, comprising: an impeller, which rotates about a central axis; a first housing accommodating the impeller; A second housing, which is disposed on one axial side of the first housing and is installed in cooperation with the first housing; a motor, which is arranged on one axial side of the impeller and accommodated in the second housing; a rotating shaft mounted on the impeller, driven by the motor, and rotating together with the impeller; and a bearing, which is arranged on the outer periphery of the rotating shaft and supports the rotating shaft; It is characterized in that A preload component and a preload support component are provided between one axial side of the impeller and the other axial side of the bearing. The preload component and the preload support component are made of different materials and are in contact with the bearing.

2. The fan according to claim 1, characterized in that: The material of the pre-compression member is metal, and the material of the pre-compression support member is resin.

3. The fan according to claim 2, characterized in that: The preload support member is disposed on one axial side of the preload member and is in contact with the bearing; and / or The preload support member is provided on the other axial side of the preload member and is in contact with the impeller or an impeller frame for supporting the impeller.

4. The fan according to claim 2, characterized in that: The preload support member includes a cover portion, an axial end surface of the cover portion is in contact with the preload member, and a radial inner periphery of the cover portion is interference-fitted with an outer periphery of the rotating shaft.

5. The fan according to claim 4, characterized in that: The preload support member further includes a wall portion, the wall portion being formed to extend from the outer periphery of the cover portion toward the preload member in the axial direction. The wall portion covers at least a portion of a radially outer surface of the pre-compression component.

6. The fan according to claim 5, characterized in that: There is a gap between the wall portion and at least one of the cover portions in the axial direction, or The wall portion is provided as a first wall portion and a second wall portion in the axial direction, and a gap is provided between the first wall portion and the second wall portion in the axial direction.

7. The fan according to claim 6, characterized in that: The preload component is a metal spring. The size of the gap is smaller than or equal to the wire diameter of the spring.

8. The fan according to claim 5, characterized in that: The radial inner peripheral surface of the wall portion has a texture that matches the pre-pressing component.

9. The fan according to claim 1, characterized in that: The material of the pre-compression component is rubber, and the material of the pre-compression support component is metal.

10. The fan according to claim 9, characterized in that: The preload support member is a sleeve disposed on the outer periphery of the rotating shaft, and the sleeve forms an interference fit with the rotating shaft.

11. The fan according to claim 9, characterized in that: The preload member is disposed on at least one end surface of the preload support member in the axial direction.

12. The fan according to claim 9, characterized in that: The radial dimension of the pre-pressing support component is larger than the radial dimension of the pre-pressing component.

13. The fan according to claim 10, characterized in that: An impeller frame is provided between the rotating shaft and the impeller, and a radial inner surface of an axially one end portion of the impeller frame abuts against a radial outer surface of the sleeve.

14. The fan according to any one of claims 1 to 13, characterized in that: The inner circumference of the first housing close to the impeller has no steps.

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