Vertical axial flow fan

Abstract

The utility model discloses a vertical axial flow fan, which relates to the technical field of fans, and comprises a vertical motor, a casing assembly and an impeller assembly, the casing assembly comprises an outer casing, an inner casing and mounting parts, and the vertical motor is mounted in the inner casing through at least two groups of mounting parts; the mounting part comprises a mounting plate, an upper centering sleeve, an upper bolt, a lower centering sleeve and a lower bolt, an upper boss is arranged at one end of the mounting plate, a lower boss is arranged at the other end of the mounting plate, an upper mounting hole and a lower mounting hole are formed in the side wall of the inner machine shell, and the upper boss and the lower boss are embedded in the upper mounting hole and the lower mounting hole respectively; an upper bolt hole and a lower bolt hole are formed in the side part of the vertical motor, an upper centering sleeve is arranged in a through hole of the upper boss and can be centered with the upper bolt hole, and an upper bolt can penetrate through the upper centering sleeve and is fixedly connected with the upper bolt hole; the lower aligning sleeve is arranged in the through hole of the lower boss and can be aligned with the lower bolt hole, and the lower bolt can penetrate through the lower aligning sleeve to be fixedly connected with the lower bolt hole.

Description

Technical Field

[0001] The utility model relates to the technical field of fans, in particular to a vertical axial-flow fan. Background Technique

[0002] With the guidance of national policies, all fields are facing the challenges of transformation and upgrading and green development. In order to meet the requirements of national policies, fields such as petrochemical, coal, power, metallurgy, and steel have increased their investment in production processes, equipment energy-saving upgrades and transformations, and have taken measures such as accelerating the adjustment of industrial structure, optimizing the energy structure, improving energy utilization efficiency, and developing clean energy.

[0003] At present, different differential requirements are put forward for fans, such as anti-corrosion, high head, energy-saving, low-noise and other characteristic requirements. There are more and more requirements for special fans that are different from traditional fans.

[0004] A vertical axial-flow fan is a fan with a specific application. Its main feature is the use of an axial-flow design, that is, the impeller (blades and hub) is directly connected to the motor. This design enables the air outlet direction of the fan to be controlled very precisely, and is suitable for occasions where a precise air supply direction is required.

[0005] The existing vertical axial-flow fan mainly consists of a vertical motor and a double-bracket hub. The vertical motor is connected to the air duct or the housing through a motor flange. However, due to the installation form of the fan and the structure of the motor, rainwater and condensate are likely to accumulate on the motor flange surface, causing water accumulation at the output shaft end of the vertical motor. A large amount of water entering the vertical motor will cause damage to the motor, seriously affecting the use safety of the fan. Content of the Utility Model

[0006] The purpose of the utility model is to provide a vertical axial-flow fan to solve the problems existing in the above-mentioned related technologies. The traditional flange connection structure between the vertical motor and the housing is changed to a side bolt hole connection structure, which can effectively avoid water ingress and damage to the vertical motor and ensure the safe operation of the fan.

[0007] To achieve the above purpose, the utility model provides the following scheme:

[0008] The utility model provides a vertical axial-flow fan, which includes a vertical motor, a housing assembly and an impeller assembly. The vertical motor is arranged in the housing assembly, and the output shaft end of the vertical motor is arranged vertically upward and is connected to the impeller assembly; the housing assembly includes an outer housing, an inner housing and an installation part. The bottom of the outer housing is used for fixing to the ground, the top of the outer housing is provided with an air outlet, the inner housing is arranged in the outer housing, and the vertical motor is installed in the inner housing through the installation part;

[0009] The installation part includes an installation plate, an upper centering sleeve, an upper bolt, a lower centering sleeve, and a lower bolt. One end of the installation plate is provided with an upper boss, and the other end is provided with a lower boss. Upper mounting holes and lower mounting holes are provided on the side wall of the inner casing. The upper boss and the lower boss are respectively embedded in the upper mounting hole and the lower mounting hole, and through holes are provided on both the upper boss and the lower boss. Upper bolt holes and lower bolt holes are provided on the side of the vertical motor. The upper centering sleeve is arranged in the through hole of the upper boss and can be centered with the upper bolt hole. The upper bolt can pass through the upper centering sleeve and be fixedly connected to the upper bolt hole. The lower centering sleeve is arranged in the through hole of the lower boss and can be centered with the lower bolt hole. The lower bolt can pass through the lower centering sleeve and be fixedly connected to the lower bolt hole. At least two groups of the installation parts are provided, and the two groups of installation parts are respectively arranged on both sides of the vertical motor.

[0010] Preferably, the cross-section of the upper centering sleeve is an annular shape; half of the outer ring surface of the upper centering sleeve can be concentric with the through hole of the upper boss and fit with the inner wall of the through hole of the upper boss, and the other half of the outer ring surface of the upper centering sleeve can be eccentric with the through hole of the upper boss.

[0011] Preferably, an upper flange positioning platform is further provided at the end of the upper centering sleeve. The upper bolt can be clamped with the side of the upper boss away from the vertical motor through the upper flange positioning platform.

[0012] Preferably, the cross-section of the lower centering sleeve is an annular shape; half of the outer ring surface of the lower centering sleeve can be concentric with the through hole of the lower boss and fit with the inner wall of the through hole of the lower boss, and the other half of the outer ring surface of the lower centering sleeve can be eccentric with the through hole of the lower boss.

[0013] Preferably, a lower flange positioning platform is further provided at the end of the lower centering sleeve. The lower bolt can be clamped with the side of the lower boss away from the vertical motor through the lower flange positioning platform.

[0014] Preferably, the inner casing includes a casing and a cover plate. The upper part of the casing is a circular cylindrical structure, the lower part of the casing is an inverted conical cylindrical structure, and a flange structure is provided at the top of the casing. The cover plate is fixed to the casing through the flange structure, and a motor shaft hole is provided on the cover plate for passing out the output shaft end of the vertical motor.

[0015] Preferably, the impeller assembly includes a support plate, a shaft sleeve, blades, and a connecting part. The support plate is installed on the output shaft end of the vertical motor through the shaft sleeve. A plurality of blades are provided, and all the blades are evenly arranged around the support plate, and each blade is connected to the support plate through a connecting part.

[0016] The connecting part includes a clamp, a locking sleeve and a locking screw. The clamp is of an integral structure and is fixed on the support plate, and a connecting hole penetrates through the clamp. The locking sleeve is a structure formed by splicing two semi-circular sleeves. A connecting column is arranged at the tail end of the blade, the connecting column penetrates through the connecting hole, and both sides of the connecting column are connected to the connecting hole through the two semi-circular sleeves respectively. At least two groups of locking screws are provided, and the two groups of locking screws can be threadedly connected to both sides of the clamp respectively to squeeze the two semi-circular sleeves, thereby locking the blade and the clamp.

[0017] Preferably, a side boss is arranged on the outer arc surface of the semi-circular sleeve. The side boss can be clamped with the connecting hole of the clamp and abutted against the corresponding locking screw.

[0018] Preferably, the connecting part further includes a positioning ring. A circular flange is arranged at the end of the connecting column of the blade, and a circular groove is arranged on one side of the clamp close to the circular flange. The positioning ring can be sleeved on the connecting column and clamped between the circular groove and the circular flange.

[0019] Preferably, the positioning ring is a structure formed by splicing two semi-circular rings.

[0020] The utility model has achieved the following technical effects compared with the related art:

[0021] The vertical axial-flow fan provided by the utility model includes a vertical motor, a casing assembly and an impeller assembly. Among them, the casing assembly includes an outer casing, an inner casing and an installation part. The installation part includes an installation plate, an upper centering sleeve, an upper bolt, a lower centering sleeve and a lower bolt. When the vertical motor is installed with the inner casing, the upper boss and the lower boss of the installation plate are respectively embedded in the upper installation hole and the lower installation hole of the inner casing. By adjusting the upper centering sleeve, the center of the upper centering sleeve is aligned with the center of the upper bolt hole of the vertical motor, and the upper bolt is passed through the upper centering sleeve and fixedly connected with the upper bolt hole. By adjusting the lower centering sleeve, the center of the lower centering sleeve is aligned with the center of the lower bolt hole of the vertical motor, and the lower bolt is passed through the lower centering sleeve and fixedly connected with the lower bolt hole, so as to realize the fixation of one side of the vertical motor and the inner casing. At least two groups of installation parts are provided in the utility model, and the two groups of installation parts are respectively arranged on both sides of the vertical motor so that the vertical motor is installed in the inner casing. The utility model changes the traditional flange connection structure between the vertical motor and the casing into a side bolt hole connection structure, which can effectively avoid the vertical motor from being damaged by water ingress and ensure the safe operation of the fan. Description of the Drawings

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 Schematic diagram of the vertical axial flow fan provided by the embodiment of the present invention;

[0024] Figure 2 For Figure 1 Enlarged view of part I in

[0025] Figure 3 For Figure 2 Cross-sectional view taken along A-A in

[0026] Figure 4 Schematic diagram of the mounting plate provided by the embodiment of the present invention;

[0027] Figure 5 Schematic diagram of the housing assembly provided by the embodiment of the present invention (the mounting part is not shown);

[0028] Figure 6 Schematic diagram of the inner housing provided by the embodiment of the present invention (the cover plate is not shown);

[0029] Figure 7 Front view of the impeller assembly provided by the embodiment of the present invention;

[0030] Figure 8 Top view of the impeller assembly provided by the embodiment of the present invention;

[0031] Figure 9 For Figure 8 Cross-sectional view taken along B-B in

[0032] Figure 10 For Figure 8 Cross-sectional view taken along C-C in

[0033] Figure 11 Schematic diagram of the support plate provided by the embodiment of the present invention;

[0034] Figure 12 Schematic diagram of the clamp provided by the embodiment of the present invention;

[0035] Figure 13 Schematic diagram of the locking sleeve provided by the embodiment of the present invention;

[0036] Figure 14 Schematic diagram of the positioning ring provided by the embodiment of the present invention.

[0037] In the figure: 1 - vertical motor, 2 - housing assembly, 201 - outer housing, 202 - inner housing, 2021 - housing body, 2022 - cover plate, 203 - mounting part, 2031 - mounting plate, 2032 - upper centering sleeve, 2033 - upper bolt, 204 - connecting plate, 3 - impeller assembly, 301 - support plate, 302 - bushing, 303 - blade, 3031 - connecting column, 304 - connecting part, 3041 - clamp, 3042 - locking sleeve, 3043 - locking screw, 3044 - bolt fastener, 3045 - positioning ring. Detailed implementation mode

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0039] The purpose of the present invention is to provide a vertical axial flow fan to solve the problems existing in the related technology. By changing the traditional flange connection structure between the vertical motor and the housing to a side bolt hole connection structure, it can effectively avoid the damage of the vertical motor caused by water ingress and ensure the safe operation of the fan.

[0040] To make the above objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation modes.

[0041] As Figure 1 shown, this embodiment provides a vertical axial flow fan, including a vertical motor 1, a housing assembly 2 and an impeller assembly 3. The vertical motor 1 is arranged in the housing assembly 2, and the output shaft end of the vertical motor 1 is arranged vertically upward and connected to the impeller assembly 3; the housing assembly 2 includes an outer housing 201, an inner housing 202 and a mounting part 203. The bottom of the outer housing 201 is used to be fixed to the ground, and an air outlet is arranged at the top of the outer housing 201. The inner housing 202 is arranged in the outer housing 201, and the vertical motor 1 is installed in the inner housing 202 through the mounting part 203, that is, the fan is connected to the ground through the housing assembly 2.

[0042] In this embodiment, as Figures 2 - 4As shown, the mounting part 203 includes a mounting plate 2031, an upper centering sleeve 2032, an upper bolt 2033, a lower centering sleeve and a lower bolt. One end of the mounting plate 2031 is provided with an upper boss, and the other end is provided with a lower boss. Upper mounting holes and lower mounting holes are provided on the side wall of the inner machine housing 202. The upper boss and the lower boss are respectively embedded in the upper mounting hole and the lower mounting hole, and through holes are provided on both the upper boss and the lower boss; on the side of the vertical motor 1, there are an upper bolt hole and a lower bolt hole. The upper centering sleeve 2032 is arranged in the through hole of the upper boss and can be centered with the upper bolt hole. The upper bolt 2033 can pass through the upper centering sleeve 2032 and be fixedly connected to the upper bolt hole; the lower centering sleeve is arranged in the through hole of the lower boss and can be centered with the lower bolt hole. The lower bolt can pass through the lower centering sleeve and be fixedly connected to the lower bolt hole, thereby connecting the vertical motor 1 to the inner machine housing 202; at least two groups of mounting parts 203 are provided, and the two groups of mounting parts 203 are respectively arranged on both sides of the vertical motor 1.

[0043] In this embodiment, the cross-section of the upper centering sleeve 2032 is annular; half of the outer ring surface of the upper centering sleeve 2032 can be concentric with the through hole of the upper boss and fit with the inner wall of the through hole of the upper boss, and the other half of the outer ring surface of the upper centering sleeve 2032 can be eccentric with the through hole of the upper boss, and the eccentric distance is designed as the maximum allowable adjustment amount between the center of the upper bolt hole of the vertical motor 1 and the center of the through hole of the upper boss. Within this adjustment amount, by rotating the upper centering sleeve 2032, its outer ring surface can be in non-gap contact with one side of the through hole of the upper boss to fix the motor; that is, in order to achieve the centering function, the center of the inner hole of the upper centering sleeve 2032 is not concentric with the center of the through hole of the upper boss, as Figure 3 shown, by rotating the upper centering sleeve 2032, one side of the upper centering sleeve 2032 can be made to fit with the inner wall of the through hole of the upper boss to position the up and down position of the vertical motor 1.

[0044] Furthermore, an upper flange positioning platform is also provided at the end of the upper centering sleeve 2032. The upper bolt 2033 can be clamped with the side of the upper boss away from the vertical motor 1 through the upper flange positioning platform. After tightening the upper bolt 2033, the left and right positions of the vertical motor 1 can be restricted.

[0045] Similarly, in this embodiment, the cross-section of the lower centering sleeve is annular; half of the outer ring surface of the lower centering sleeve can be concentric with the through hole of the lower boss and fit with the inner wall of the through hole of the lower boss, and the other half of the outer ring surface of the lower centering sleeve can be eccentric with the through hole of the lower boss, and the eccentric distance is designed as the maximum allowable adjustment amount between the center of the lower bolt hole of the vertical motor 1 and the center of the through hole of the lower boss. Within this adjustment amount, by rotating the lower centering sleeve, its outer ring surface can be in non-gap contact with one side of the through hole of the lower boss to fix the motor.

[0046] Furthermore, a lower flange positioning platform is provided at the end of the centering sleeve, and the lower bolt can be clamped to the side of the lower boss away from the vertical motor 1 through the lower flange positioning platform.

[0047] In this embodiment, as Figure 5 shown, a flange interface for connecting to the ground is provided at the bottom of the outer casing 201, and the inner casing 202 is connected to the outer casing 201 through a connecting plate 204; as Figure 6 shown, the inner casing 202 includes a casing 2021 and a cover plate 2022. Specifically, the casing 2021 in this embodiment is welded by three parts. Among them, the upper part of the casing 2021 is a circular cylindrical structure, which is a thin-walled structure, and there are two rows of round holes (i.e., upper mounting holes and lower mounting holes) on its side wall; the lower part of the casing 2021 is an inverted conical cylindrical structure, which is also a thin-walled structure, and its shape can improve the air flow; a flange structure is provided at the top of the casing 2021; the cover plate 2022 is fixed to the casing 2021 through the flange structure, and a motor shaft hole is provided on the cover plate 2022 for passing out the output shaft end of the vertical motor 1, and the cover plate 2022 can play a sealing role.

[0048] In this embodiment, as Figures 7 - 10 shown, the impeller assembly 3 includes a support plate 301, a bushing 302, blades 303 and a connecting part 304. The support plate 301 is mounted on the output shaft end of the vertical motor 1 through the bushing 302. Specifically, as Figure 11 shown, the support plate 301 in this embodiment is a circular plate, and the support plate 301 is mounted above the bushing 302, and the two are positioned by a spigot and fixed by bolts; there are four blades 303, and all the blades 303 are evenly arranged around the support plate 301, and each blade 303 is connected to the support plate 301 through a connecting part 304.

[0049] Furthermore, the connecting part 304 includes a clamp 3041, a locking sleeve 3042 and a locking screw 3043. The clamp 3041 is an integral structure and is fixed to the support plate 301, and a connecting hole penetrates through the clamp 3041. Specifically, as Figure 12 shown, a ring groove is provided on the end face of the support plate 301 in contact with the clamp 3041 to position the clamp 3041. At the same time, in order to overcome the centrifugal force generated during the operation of the impeller assembly 3, the clamp 3041 is fixed to the support plate 301 through four groups of bolt fasteners 3044; as Figure 13As shown, the locking sleeve 3042 is a structure formed by splicing two semi-circular sleeves. A connecting column 3031 is provided at the tail end of the blade 303. The connecting column 3031 passes through the connecting hole, and both sides of the connecting column 3031 are connected to the connecting hole through two semi-circular sleeves respectively. That is, the connecting column 3031 together with the two semi-circular sleeves can be inserted into the clamp 3041 together to realize the connection between the blade 303 and the clamp 3041. At least two groups of locking screws 3043 are provided. The two groups of locking screws 3043 can be threadedly connected to both sides of the clamp 3041 respectively to squeeze the two semi-circular sleeves, thereby locking the blade 303 and the clamp 3041. Specifically, the locking screw 3043 in this embodiment is preferably an internal hexagonal screw.

[0050] In this embodiment, a side convex platform is provided on the outer arc surface of the semi-circular sleeve. The side convex platform can be clamped with the connecting hole of the clamp 3041 and abutted against the corresponding locking screw 3043.

[0051] In this embodiment, the connecting portion 304 further includes a positioning ring 3045, as Figure 14 shown, the positioning ring 3045 in this embodiment is a structure formed by splicing two semi-circular rings. An annular flange is provided at the end of the connecting column 3031 of the blade 303, and an annular groove is provided on one side of the clamp 3041 close to the annular flange. The positioning ring 3045 can be sleeved on the connecting column 3031 and clamped between the annular groove and the annular flange to realize the installation and positioning of the blade 303.

[0052] It should be noted that in this embodiment, a connecting column 3031 is provided at the tail end of the blade 303, and an annular flange is provided at the end of the connecting column 3031 (that is, the connecting column 3031 has a flange). Through the connecting portion 304, the connection between the above-mentioned blade root structure and the integral clamp 3041 is realized, solving the problem that the existing clamp can only be made into a split structure. At the same time, the connection strength is improved.

[0053] When installing the blade 303, first insert the connecting column 3031 of the blade 303 into the connecting hole of the clamp 3041, then place the locking sleeve 3042 on both sides of the connecting column 3031 of the blade 303 and install it into the clamp 3041 from the blade tip direction. Then, install the positioning ring 3045 on both sides of the end of the connecting column 3031 of the blade 303, and then move the blade 303 in the blade tip direction to make the positioning ring 3045 enter the annular groove of the clamp 3041. Finally, tighten the locking screw 3043 to squeeze the locking sleeve 3042, generating frictional force to fix the blade 303 on the support plate 301.

[0054] It should be noted that, due to the structure of the existing motor directly connected to the double-bracket impeller, there is a problem that the distance between the fan blades and the internal structure of the fan is relatively close. During the operation of the fan, a periodic starting load will be formed, which is likely to cause fatigue damage and airflow erosion of the fan blades. If the existing single-bracket structure is adopted, its installation form and hub structure will result in poor bolt force and is likely to cause bolt fracture. In view of the defects existing in the above-mentioned related technologies, the present utility model designs a single-bracket blade locking structure, that is, an integrated clamp 3041 is used and installed on the bracket 301 with a ring groove. When the fan operates, the main stress-bearing components are the bracket 301 and the clamp 3041, and the bolts mainly bear the tensile force. Therefore, the impeller assembly 3 provided by the present utility model has good strength and safety, further ensuring the safe and stable operation of the fan.

[0055] In the present utility model, specific examples are used to elaborate on the principle and implementation manner of the present utility model. The description of the above embodiments is only used to help understand the method and its core idea of the present utility model; at the same time, for those of ordinary skill in the art, according to the idea of the present utility model, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present utility model.

Claims

1. A vertical axial flow fan, comprising a vertical motor, a housing assembly and an impeller assembly, wherein the vertical motor is arranged in the housing assembly, and the output shaft end of the vertical motor is arranged vertically upward and connected to the impeller assembly; characterized in that: The housing assembly comprises an outer housing, an inner housing and a mounting portion, the bottom of the outer housing is used to be fixed to the ground, the top of the outer housing is provided with an air outlet, the inner housing is arranged in the outer housing, and the vertical motor is installed in the inner housing through the mounting portion; The mounting portion comprises a mounting plate, an upper adjusting sleeve, an upper bolt, a lower adjusting sleeve and a lower bolt, an upper boss is arranged at one end of the mounting plate, and a lower boss is arranged at the other end, an upper mounting hole and a lower mounting hole are arranged on the side wall of the inner housing, the upper boss and the lower boss are respectively embedded in the upper mounting hole and the lower mounting hole, and through holes are arranged on both the upper boss and the lower boss; an upper bolt hole and a lower bolt hole are arranged on the side of the vertical motor, the upper adjusting sleeve is arranged in the through hole of the upper boss and can be aligned with the upper bolt hole, and the upper bolt can pass through the upper adjusting sleeve and be fixedly connected to the upper bolt hole; the lower adjusting sleeve is arranged in the through hole of the lower boss and can be aligned with the lower bolt hole, and the lower bolt can pass through the lower adjusting sleeve and be fixedly connected to the lower bolt hole; the mounting portion is provided with at least two groups, and the two groups of mounting portions are respectively arranged on both sides of the vertical motor.

2. The vertical axial flow fan according to claim 1, characterized in that: The cross-section of the upper adjusting sleeve is circular; half of the outer ring surface of the upper adjusting sleeve can be concentrically arranged with the through hole of the upper boss and fit with the inner wall of the through hole of the upper boss, and the other half of the outer ring surface of the upper adjusting sleeve can be eccentrically arranged with the through hole of the upper boss.

3. The vertical axial flow fan according to claim 1, characterized in that: An upper flange positioning platform is also provided at the end of the upper centering sleeve, and the upper bolt can be clamped with a side of the upper boss away from the vertical motor through the upper flange positioning platform.

4. The vertical axial flow fan according to claim 1, characterized in that: The cross-section of the lower adjusting sleeve is circular; half of the outer ring surface of the lower adjusting sleeve can be concentrically arranged with the through hole of the lower boss and fit with the inner wall of the through hole of the lower boss, and the other half of the outer ring surface of the lower adjusting sleeve can be eccentrically arranged with the through hole of the lower boss.

5. The vertical axial flow fan according to claim 1, characterized in that: A lower flange positioning platform is also provided at the end of the lower centering sleeve, and the lower bolt can be clamped with a side of the lower boss away from the vertical motor through the lower flange positioning platform.

6. The vertical axial flow fan according to claim 1, characterized in that: The inner casing includes a shell and a cover plate, the upper part of the shell is a circular cylindrical structure, the lower part of the shell is an inverted conical cylindrical structure, and a flange structure is arranged on the top of the shell; the cover plate is fixed to the shell through the flange structure, and a motor shaft hole is arranged on the cover plate, and the motor shaft hole is used to pass the output shaft end of the vertical motor.

7. The vertical axial flow fan according to claim 1, characterized in that: The impeller assembly includes a support plate, a sleeve, blades and a connecting portion, wherein the support plate is installed on the output shaft end of the vertical motor through the sleeve; a plurality of blades are provided, all of which are evenly arranged around the support plate, and each of the blades is connected to the support plate through one of the connecting portions; The connecting part includes a clamp, a locking sleeve and a locking screw. The clamp is an integrated structure and is fixed to the support plate, and a connecting hole is penetrated through the clamp. The locking sleeve is a structure composed of two semi-arc sleeves. A connecting column is provided at the tail end of the blade, and the connecting column is passed through the connecting hole, and the two sides of the connecting column are respectively connected to the connecting hole through the two semi-arc sleeves. At least two groups of locking screws are provided, and the two groups of locking screws can be threadedly connected to the two sides of the clamp respectively to squeeze the two semi-arc sleeves, thereby locking the blade and the clamp.

8. The vertical axial flow fan according to claim 7, characterized in that: A side boss is arranged on the outer arc surface of the semi-arc sleeve, and the side boss can be engaged with the connecting hole of the clamp and abut against the corresponding locking screw.

9. The vertical axial flow fan according to claim 7, characterized in that: The connecting portion also includes a positioning ring, an annular flange is provided at the end of the connecting column of the blade, and an annular groove is provided on the side of the clamp close to the annular flange, and the positioning ring can be sleeved on the connecting column and clamped between the annular groove and the annular flange.

10. The vertical axial flow fan according to claim 9, characterized in that: The positioning ring is a structure formed by splicing two semicircular rings.

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