EC fan in which adjustment and fitting are convenient

Abstract

An EC fan in which adjustment and fitting are convenient, comprising a motor (1), an impeller (11), a Venturi cylinder (12), and a support assembly (2). The motor (1), the impeller (11), and the Venturi cylinder (12) are all mounted on the support assembly (2). The impeller (11) is rotatably connected to the motor (1). The impeller (11) and the Venturi cylinder (12) are coaxial. The support assembly (2) comprises a seat plate (21), a mounting frame (22), and an adjustment plate (23). The motor (1) is fixedly mounted on the mounting frame (22). The mounting frame (22) is connected to the seat plate (21). The Venturi cylinder (12) is mounted on the adjustment plate (23). The support assembly (2) further comprises an adjustment assembly (3). The adjustment assembly (3) is used for controlling the movement or fixation of the adjustment plate (23) relative to the seat plate (21). The movement direction of the adjustment plate (23) relative to the seat plate (21) is parallel to the axial direction of the impeller (11).

Description

EC fan convenient to adjust and match TECHNICAL FIELD

[0001] The present application relates to the field of ventilation machinery, in particular to an EC fan convenient to adjust and match. BACKGROUND

[0002] The EC fan refers to a centrifugal fan using a digital brushless DC outer rotor motor or a centrifugal fan using an EC motor; the main structure thereof includes a motor, an impeller, a Venturi cylinder and a support, the motor is used to drive the impeller to rotate, the Venturi cylinder is located on the side away from the motor and coaxial with the impeller, and the support is used to mount various components.

[0003] In the related art, the impeller is connected with the output shaft of the motor, and the support is usually shaped by cold working process using pipe steel and round steel, and the support, the electrode and the Venturi cylinder are fixed by welding or bolt connection.

[0004] The above related technology has the following disadvantages: according to the working principle of the EC fan, the Venturi cylinder and the edge of the end of the impeller require a certain size of axial overlap, and the distance of the overlap is an important factor determining the performance of the EC fan; after the assembly of various components is completed, the axial relative position of the impeller and the Venturi cylinder is fixed, and it is difficult to adjust and correct the matching deviation of the impeller and the Venturi cylinder caused by objective factors such as machining error. SUMMARY

[0005] In order to improve the above problems, the present application provides an EC fan convenient to adjust and match.

[0006] The EC fan convenient to adjust and match provided by the present application adopts the following technical scheme:

[0007] The EC fan convenient to adjust and match comprises a motor, an impeller, a Venturi cylinder and a support assembly, the motor, the impeller and the Venturi cylinder are all mounted on the support assembly, the impeller and the motor are rotationally connected, the impeller and the Venturi cylinder are coaxial, the support assembly comprises a seat plate, a mounting frame and an adjusting plate, the motor is fixedly mounted on the mounting frame, the mounting frame is connected with the seat plate, the Venturi cylinder is mounted on the adjusting plate, the support assembly further comprises an adjusting assembly, the adjusting assembly is used to control the movement or fixation of the adjusting plate relative to the seat plate, and the movement direction of the adjusting plate relative to the seat plate is parallel to the axial direction of the impeller.

[0008] By adopting the above technical scheme, during the installation process, the adjusting plate is adjusted by operating the adjusting assembly according to the specific matching condition of the Venturi cylinder and the end of the impeller, so as to change the axial matching precision of the Venturi cylinder and the impeller.

[0009] Preferably, the adjusting assembly comprises a surrounding plate and a positioning bolt, the surrounding plate is fixedly connected with the base plate, a matching flap is fixedly connected on the adjusting plate, the plate surface of the matching flap is attached to the plate surface of the surrounding plate, a waist-shaped hole is formed on the surrounding plate, the length direction of the waist-shaped hole is parallel to the axial direction of the Venturi tube, and the positioning bolt passes through the waist-shaped hole and the matching flap and is threadedly connected with a nut.

[0010] By adopting the above technical scheme, the positioning bolt can be adjusted in the length range of the waist-shaped hole, thereby realizing the installation position adjustment of the adjusting plate carrying the Venturi tube along the length direction of the waist-shaped hole, and further realizing the axial relative position adjustment of the Venturi tube and the impeller during assembly.

[0011] Preferably, the surrounding plate is welded with the base plate, the mounting frame comprises a supporting leg, the side wall of the supporting leg is in contact with the plate surface of the surrounding plate, one end of the supporting leg is welded with the base plate, the edge of the surrounding plate and the end of the supporting leg are both fixedly connected with a positioning block, and the base plate is provided with a positioning hole or a positioning groove for inserting the positioning block.

[0012] By adopting the above technical scheme, the positioning hole or the positioning groove guides the position of the positioning block on the surrounding plate or the supporting leg, thereby improving the installation accuracy of the surrounding plate and the mounting frame relative to the base plate.

[0013] Preferably, the edge of the Venturi tube is coaxially integrally formed with a mounting extension plate, the plate surface of the mounting extension plate is perpendicular to the axial direction of the Venturi tube, a mounting hole is formed on the mounting extension plate, a fixing hole is formed on the adjusting plate, the diameter of the mounting hole is smaller than the diameter of the fixing hole, an installation bolt is arranged on the adjusting plate, the installation bolt passes through the mounting hole and the fixing hole and is threadedly connected with a nut.

[0014] By adopting the above technical scheme, since there is a radial size difference between the mounting hole and the fixing hole, during assembly, the adjusting plate and the matching flap have the condition of small position adjustment along the plate surface direction, thereby improving the coaxiality of the Venturi tube and the impeller during assembly.

[0015] Preferably, a shaft positioning assembly is detachably arranged on the adjusting plate at the fixing hole, the mounting hole and the fixing hole are arranged in more than four, and the mounting hole and the fixing hole are arranged in an annular array around the Venturi tube, during the mutual installation of the Venturi tube and the adjusting plate, the installation bolt and the shaft positioning assembly are alternatively arranged at the fixing hole.

[0016] Preferably, the shaft positioning assembly comprises a shaft positioning block and a lever, the shaft positioning block is located on the side of the adjusting plate away from the mounting extension plate and is fixed opposite to the adjusting plate, the lever is connected with the shaft positioning block and swings relative to the shaft positioning block, and the lever passes through the mounting hole.

[0017] By adopting the technical scheme, in the process of installing the Venturi cylinder and the adjusting plate, the operator swings the lever to apply a pushing force to the installation extension plate, thereby controlling the lateral movement of the installation extension plate and the Venturi cylinder, changing the lateral position of the Venturi cylinder, and adjusting the coaxiality of the Venturi cylinder and the impeller.

[0018] Preferably, the fixed shaft block is embedded with an adjusting ball, the lever passes through the adjusting ball and is coaxially connected with the adjusting ball through threads, the end of the lever is coaxially fixedly connected with a limiting ball, the limiting ball is elastic, the diameter of the limiting ball is greater than the hole diameter of the installation hole, and the limiting ball is located on the side of the installation extension plate away from the adjusting plate and abuts against the installation extension plate.

[0019] By adopting the technical scheme, the adjusting ball can be used as a ball joint structure for the lever to swing freely relative to the fixed shaft block, and the limiting ball can make the end sidewall of the lever always effectively abut against the hole wall of the installation hole to apply a pushing force to the installation extension plate.

[0020] Preferably, a matching groove is formed on the side of the adjusting plate away from the installation extension plate, a matching protrusion is fixedly connected to the fixed shaft block, and the matching protrusion is inserted into the matching groove.

[0021] By adopting the technical scheme, the matching groove and the matching protrusion cooperate with each other to make the fixed shaft block have high position stability relative to the adjusting plate.

[0022] Preferably, a push rod ring is arranged on the side of the fixed shaft block away from the adjusting plate, the push rod ring is sleeved on the lever, the push rod ring is magnetically attached to the fixed shaft block, and the inner diameter of the push rod ring is greater than the diameter of the lever.

[0023] By adopting the technical scheme, when the push rod ring and the fixed shaft block are magnetically attached to each other, the two have a large friction force to make the push rod ring keep position stability, and the lever can also keep a stable angle posture under the continuous pushing force of the push rod ring.

[0024] Preferably, a power-assisted wedge block is slidably arranged on the push rod ring, the sliding direction of the power-assisted wedge block is inclined relative to the axis of the push rod ring, a power-assisted ball is embedded on the side of the power-assisted wedge block facing the fixed shaft block, when the power-assisted wedge block moves close to the axis of the push rod ring, the power-assisted wedge block also moves close to the fixed shaft block, and the power-assisted ball abuts against the fixed shaft block.

[0025] By adopting the technical scheme, when the power-assisted wedge block moves close to the axis of the push rod ring, the power-assisted wedge block also has a tendency to move close to the fixed shaft block, at this time, the power-assisted ball abuts against the fixed shaft block, thereby the push rod ring can be pushed away from the fixed shaft block by a certain distance, and the operator can conveniently push the push rod ring.

[0026] In summary, the present application has at least one of the following beneficial technical effects:

[0027] 1. By adjusting the plate and the setting of the adjusting assembly, during the installation process, according to the specific matching of the end of the volute and the impeller, the adjusting assembly is operated to adjust the adjusting plate, so as to change the axial matching precision of the volute and the impeller;

[0028] 2. By the setting of the mounting hole and the fixing hole and the mounting bolt, due to the size gap between the mounting hole and the fixing hole, the mounting extension plate has an adjustable amount in the parallel direction of the plate surface relative to the adjusting plate, and the coincidence degree of the axis of the impeller and the axis of the volute can be adjusted, and the matching precision of the two is further improved. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a schematic diagram of the overall structure of the EC fan for embodying the convenient adjustment and matching according to the embodiment of the present application.

[0030] Figure 2 is an exploded schematic diagram of the structure of the support assembly according to the embodiment of the present application.

[0031] Figure 3 is a schematic diagram of the structure of the fixed shaft assembly according to the second embodiment of the present application.

[0032] Figure 4 is a schematic diagram of the structure of the working principle of the fixed shaft assembly according to the embodiment of the present application.

[0033] Explanation of reference numerals: 1, motor; 11, impeller; 12, volute; 121, mounting extension plate; 122, mounting hole; 2, support assembly; 21, seat plate; 22, mounting bracket; 221, supporting leg; 23, adjusting plate; 231, matching flap; 232, fixing hole; 233, matching groove; 234, mounting bolt; 24, positioning block; 25, positioning hole; 26, positioning groove; 3, adjusting assembly; 31, surrounding plate; 311, waist-shaped hole; 32, positioning bolt; 4, fixed shaft assembly; 41, fixed shaft block; 411, matching protruding block; 42, adjusting ball; 43, lever; 431, limiting ball; 44, push rod ring; 45, power wedge; 451, power ball. DETAILED DESCRIPTION

[0034] The present application will be further described in detail below in combination with Figures 1-4.

[0035] Embodiment one:

[0036] The embodiment of the present application discloses an EC fan convenient for adjustment and matching, as shown in Figure 1, which comprises a motor 1, an impeller 11, a volute 12 and a support assembly 2, and the support assembly 2 is used for directly or indirectly mounting the motor 1, the impeller 11 and the volute 12. The impeller 11 is connected with the output shaft of the motor 1, and the motor 1 is used for driving the impeller 11 to rotate; the volute 12 is located on the side of the impeller 11 away from the motor 1.

[0037] As shown in FIG. 1 and 2, the bracket assembly 2 comprises a seat plate 21, a mounting frame 22 and an adjusting plate 23, the motor 1 is mounted on the mounting frame 22, the Venturi cylinder 12 is mounted on the adjusting plate 23, the seat plate 21 is provided with an adjusting assembly 3, the adjusting assembly 3 comprises a surrounding plate 31 and a positioning bolt 32, the mounting frame 22 and the surrounding plate 31 are located on the same side of the seat plate 21 and are fixedly connected with the seat plate 21. The adjusting plate 23 is mounted on the seat plate 21 through the adjusting assembly 3, and the adjusting assembly 3 can be used to control the movement or fixation of the adjusting plate 23 relative to the seat plate 21, and the movement direction of the adjusting plate 23 relative to the seat plate 21 is parallel to the axial direction of the impeller 11. The plate surface of the adjusting plate 23 is square, a square through hole is formed in the center of the seat plate 21, and the adjusting plate 23 is located in the through hole. The mounting frame 22 comprises four supporting legs 221 made of angle steels, and the surrounding plate 31 and the supporting legs 221 are welded with the seat plate 21; the edges of the surrounding plate 31 and the end portions of the supporting legs 221 are integrally formed with positioning blocks 24, the plate surface of the seat plate 21 is provided with positioning holes 25 for the positioning blocks 24 of the supporting legs 221 to be inserted, and the hole wall of the square through hole of the seat plate 21 is provided with positioning grooves 26 for the positioning blocks 24 of the surrounding plate 31 to be inserted, after each positioning block 24 is inserted into the positioning hole 25 or the positioning groove 26, the plate surface of the surrounding plate 31 is perpendicular to the plate surface of the seat plate 21, and the length direction of the supporting leg 221 is also perpendicular to the plate surface of the seat plate 21, and the cooperation of the positioning block 24 and the positioning hole 25 or the positioning groove 26 is used to improve the dimensional accuracy of the welding cooperation. The surrounding plate 31 comprises four surrounding plates 31, which form a square frame, the square frame corresponds to the square through hole on the seat plate 21, and the four supporting legs 221 are respectively located at the four corner edges of the square frame, and the side wall of the supporting leg 221 is in contact with the plate surface of the surrounding plate 31.

[0038] As shown in FIG. 1 and 2, a circular through hole is formed in the center of the adjusting plate 23 for the Venturi cylinder 12 to pass through, the edge of the Venturi cylinder 12 is integrally formed with a mounting extension plate 121 coaxially, the plate surface of the mounting extension plate 121 is perpendicular to the axial direction of the Venturi cylinder 12, six mounting holes 122 are formed in the mounting extension plate 121, six fixing holes 232 are formed in the adjusting plate 23, and each mounting hole 122 and fixing hole 232 are arranged in an annular array around the axis of the Venturi cylinder 12. Each fixing hole 232 corresponds to one mounting hole 122, the hole diameter of the mounting hole 122 is smaller than the hole diameter of the fixing hole 232, a mounting bolt 234 is inserted through the mounting hole 122 and the fixing hole 232 and is threadedly connected with a nut. Due to the radial size deviation between the mounting hole 122 and the fixing hole 232, the adjusting plate 23 and the cooperating flange plate 231 have the condition of small position adjustment along the plate surface direction during the assembly process, thereby improving the coaxiality of the Venturi cylinder 12 and the impeller 11 during the assembly.

[0039] As shown in FIG. 1 and 2, the four edges of the adjusting plate 23 are all bent to form the matching flaps 231, when the adjusting plate 23 is located in the square through hole on the seat plate 21, the plate surface of the matching flaps 231 is attached to the plate surface of the surrounding plate 31. The surrounding plate 31 is provided with a waist-shaped hole 311, the length direction of the waist-shaped hole 311 is parallel to the axial direction of the Venturi cylinder 12, the positioning bolt 32 passes through the waist-shaped hole 311 and the matching flaps 231 and is screwed with a nut. The positioning bolt 32 can be adjusted in position within the length range of the waist-shaped hole 311, thereby realizing the adjustment of the mounting position of the adjusting plate 23 carrying the Venturi cylinder 12 along the length direction of the waist-shaped hole 311, and further adjusting the axial relative position of the Venturi cylinder 12 and the impeller 11 during assembly.

[0040] The implementation principle of the EC fan convenient for adjustment and cooperation in the embodiment of the application is as follows:

[0041] First, the surrounding plate 31 and the mounting frame 22 are welded on the seat plate 21 respectively, then the Venturi cylinder 12 is mounted on the adjusting plate 23 and the motor 1 is mounted on the mounting frame 22, the mounting position of the adjusting plate 23 and the surrounding plate 31 is adjusted through the axial relative position adjustment of the impeller 11 and the Venturi cylinder 12, then the positioning bolt 32 is screwed, the mounting position of the mounting extension plate 121 and the adjusting plate 23 is adjusted through the coaxial adjustment of the impeller 11 and the Venturi cylinder 12, then the mounting bolt 234 is screwed, and the EC fan is assembled.

[0042] Embodiment two:

[0043] As shown in FIG. 3, the difference from the embodiment one is that in the embodiment, the adjusting plate 23 is provided with the shaft positioning assembly 4 at the part of the fixing holes 232 in a detachable manner, the shaft positioning assembly 4 is used for providing convenience for the cooperation of the mounting extension plate 121 and the adjusting plate 23. The mounting holes 122 and the fixing holes 232 are all six, during the mounting process of the Venturi cylinder 12 and the adjusting plate 23, the shaft positioning assembly 4 is placed at three fixing holes 232 of the adjusting plate 23, one vacant fixing hole 232 is spaced between every two shaft positioning assemblies 4, or the mounting bolt 234 can pass through the vacant fixing hole 232 and the mounting hole 122 at the same time, but the nut is not screwed first.

[0044] As shown in FIG. 3 and 4, the fixed shaft assembly 4 comprises a fixed shaft block 41, a lever 43 and a push rod ring 44. The fixed shaft block 41 is annular, and one end surface of the fixed shaft block 41 is integrally formed with a matching protrusion 411. The adjusting plate 23 is provided with a matching groove 233 on the side away from the mounting extension plate 121, and the matching protrusion 411 is inserted into the matching groove 233. After the matching protrusion 411 is inserted into the matching groove 233, the fixed shaft block 41 is coaxial with the fixing hole 232. The fixed shaft block 41 is embedded with an adjusting ball 42, and the adjusting ball 42 is provided with a threaded through hole. One end of the lever 43 is fixedly connected with a limiting ball 431, and the limiting ball 431 is made of rubber and has elastic deformation capacity. The diameter of the lever 43 is smaller than the space of the mounting hole 122, and the lever 43 passes through the mounting hole 122, the fixing hole 232 and the adjusting ball 42 in sequence. The lever 43 is coaxially and threadedly connected with the adjusting ball 42, and the adjusting ball 42 can be used as a ball joint structure for the lever 43 to swing freely relative to the fixed shaft block 41. The friction between the adjusting ball 42 and the fixed shaft block 41 is greater than the friction of the threaded pair between the lever 43 and the adjusting ball 42. The diameter of the limiting ball 431 is greater than the hole diameter of the mounting hole 122, that is, after the lever 43 is screwed on the adjusting ball 42, the limiting ball 431 abuts against the mounting extension plate 121 so that the mounting extension plate 121 abuts against the adjusting plate 23.

[0045] As shown in FIG. 3 and 4, the material of the fixed shaft block 41 is iron, the push rod ring 44 is made of magnet, the push rod ring 44 is adsorbed on the side of the fixed shaft block 41 away from the adjusting plate 23, the end of the push rod 43 away from the limiting ball 431 also passes through the inner cavity of the push rod ring 44, the inner diameter of the push rod ring 44 is larger than the diameter of the push rod 43. Artificially operating the push rod ring 44 to move in the direction perpendicular to the axial direction of itself, the push rod ring 44 abuts the push rod 43 through the inner wall to make the push rod 43 swing, the push rod 43 pushes the installation extension plate 121 to move, thereby realizing the change of the transverse position of the Venturi cylinder 12. The push rod ring 44 and the fixed shaft block 41 have strong magnetic attraction force, and the friction force between them is also large. In order to improve the convenience of the push rod ring 44 to move, the power wedge 45 is slidably arranged on the push rod ring 44, the sliding direction of the power wedge 45 relative to the push rod ring 44 is inclined relative to the axis of the push rod ring 44, the side of the power wedge 45 facing the fixed shaft block 41 is embedded with the power ball 451, when the power wedge 45 moves close to the axis of the push rod ring 44, the power wedge 45 also has a tendency to move close to the fixed shaft block 41, at this time, the power ball 451 abuts and contacts the fixed shaft block 41, thereby the push rod ring 44 can be pushed away from the fixed shaft block 41 by 1-2 mm; the power wedge 45 is provided with two and is symmetrically arranged on the opposite sides of the axis of the push rod ring 44. In the process of operating the push rod ring 44 to push the push rod 43 to swing, the push rod 43 can be regarded as a lever, the adjusting ball 42 is the fulcrum, because the friction force between the push rod ring 44 and the fixed shaft block 41 is large, even if the installation hole 122 of the installation extension plate 121 is decentered with the fixed hole 232 after being pushed, the axis of the push rod 43 is angularly offset with the axis of the fixed hole 232, the limiting ball 431 is deformed, the reaction force of the installation extension plate 121 on the push rod 43 still cannot overcome the friction force between the push rod ring 44 and the fixed shaft block 41, that is, the push rod 43 only swings under the push of the push rod ring 44.

[0046] During installation, three fixed holes 232 are arranged with the fixed shaft assembly 4, the other three fixed holes 232 are first penetrated by the installation bolts 234, and then the operator operates the fixed shaft assembly 4 while measuring the coaxiality of the Venturi cylinder 12 relative to the impeller 11 in real time, when the debugging is completed, the nuts on the three existing installation bolts 234 are immediately tightened, then the fixed shaft assembly 4 is removed, and the installation bolts 234 and nuts are tightened at the remaining three fixed holes 232, thereby completing the installation of the Venturi cylinder 12 relative to the adjusting plate 23.

[0047] The above are the preferred embodiments of the present application, which do not limit the protection scope of the present application, therefore: any equivalent changes made on the structure, shape and principle of the present application should be covered within the protection scope of the present application.

Claims

1. An EC fan that is easy to adjust and coordinate, comprising a motor (1), an impeller (11), a venturi cylinder (12), and a support assembly (2), wherein the motor (1), impeller (11), and venturi cylinder (12) are all mounted on the support assembly (2), the impeller (11) and the motor (1) are rotatably connected, and the impeller (11) and the venturi cylinder (12) are coaxial, characterized in that: The bracket assembly (2) comprises a base plate (21), a mounting frame (22) and an adjusting plate (23), the motor (1) is fixedly installed on the mounting frame (22), the mounting frame (22) is connected with the base plate (21), the Venturi cylinder (12) is installed on the adjusting plate (23), the bracket assembly (2) further comprises an adjusting assembly (3), the adjusting assembly (3) is used for controlling the movement or fixation of the adjusting plate (23) relative to the base plate (21), and the movement direction of the adjusting plate (23) relative to the base plate (21) is parallel to the axial direction of the impeller (11).

2. An EC fan with easy adjustment of fit according to claim 1, characterized in that: The adjusting assembly (3) comprises a surrounding plate (31) and a positioning bolt (32), the surrounding plate (31) is fixedly connected with the base plate (21), the adjusting plate (23) is fixedly connected with a matching flap (231), the plate surface of the matching flap (231) is attached to the plate surface of the surrounding plate (31), the surrounding plate (31) is provided with a waist-shaped hole (311), the length direction of the waist-shaped hole (311) is parallel to the axial direction of the Venturi cylinder (12), and the positioning bolt (32) penetrates through the waist-shaped hole (311) and the matching flap (231) and is threadedly connected with a nut.

3. An EC fan with easy adjustment of fit according to claim 1 or 2, characterized in that: The surrounding plate (31) is welded with the base plate (21), the mounting frame (22) comprises a supporting leg (221), the side wall of the supporting leg (221) is in contact with the plate surface of the surrounding plate (31), one end of the supporting leg (221) is welded with the base plate (21), the edge of the surrounding plate (31) and the end of the supporting leg (221) are fixedly connected with a positioning block (24), and the base plate (21) is provided with a positioning hole (25) or a positioning groove (26) for inserting the positioning block (24).

4. An EC fan with easy adjustment of fit according to claim 1 or 2, characterized in that: The edge of the Venturi cylinder (12) is coaxially and integrally formed with a mounting extension plate (121), the plate surface of the mounting extension plate (121) is perpendicular to the axial direction of the Venturi cylinder (12), the mounting extension plate (121) is provided with a mounting hole (122), the adjusting plate (23) is provided with a fixing hole (232), the hole diameter of the mounting hole (122) is smaller than the hole diameter of the fixing hole (232), the adjusting plate (23) is provided with a mounting bolt (234), the mounting bolt (234) penetrates through the mounting hole (122) and the fixing hole (232) and is threadedly connected with a nut.

5. An EC fan with easy adjustment of fit according to claim 4, characterized in that: The adjusting plate (23) is detachably provided with an axis positioning assembly (4) at the fixing hole (232), the mounting hole (122) and the fixing hole (232) are provided with more than four, and the mounting hole (122) and the fixing hole (232) are arranged in an annular array around the Venturi cylinder (12), during the mutual installation of the Venturi cylinder (12) and the adjusting plate (23), the mounting bolt (234) and the axis positioning assembly (4) are alternatively arranged at the fixing hole (232), and the mounting bolt (234) and the axis positioning assembly (4) are alternately arranged.

6. An EC fan with easy adjustment of fit according to claim 5, characterized in that: The fixed shaft assembly (4) comprises a fixed shaft block (41) and a push rod (43), the fixed shaft block (41) is located on the side of the adjusting plate (23) away from the mounting extension plate (121) and is fixed opposite to the adjusting plate (23), the push rod (43) is connected with the fixed shaft block (41) and swings relative to the fixed shaft block (41), and the push rod (43) passes through the mounting hole (122).

7. An EC fan with easy adjustment of fit according to claim 6, characterized in that: The fixed shaft block (41) is embedded with an adjusting ball (42), the push rod (43) passes through the adjusting ball (42) and is coaxially screwed with the adjusting ball (42), the end of the push rod (43) is coaxially fixedly connected with a limiting ball (431), the limiting ball (431) is elastic, the diameter of the limiting ball (431) is greater than the hole diameter of the mounting hole (122), and the limiting ball (431) is located on the side of the mounting extension plate (121) away from the adjusting plate (23) and abuts against the mounting extension plate (121).

8. An EC fan with easy adjustment of fit according to claim 7, characterized in that: The adjusting plate (23) is provided with a matching groove (233) on the side away from the mounting extension plate (121), and the fixed shaft block (41) is fixedly connected with a matching protrusion (411), and the matching protrusion (411) is inserted into the matching groove (233).

9. An EC fan for ease of fit adjustment according to claim 7 or 8, characterized in that: The fixed shaft block (41) is provided with a push rod ring (44) on the side away from the adjusting plate (23), the push rod ring (44) is sleeved outside the push rod (43), the push rod ring (44) is magnetically attached to the fixed shaft block (41), and the inner diameter of the push rod ring (44) is greater than the diameter of the push rod (43).

10. An EC fan with easy adjustment of fit according to claim 9, characterized in that: The push rod ring (44) is provided with a power wedge (45) slidingly arranged thereon, the sliding direction of the power wedge (45) relative to the push rod ring (44) is inclined relative to the axis of the push rod ring (44), the side of the power wedge (45) facing the fixed shaft block (41) is embedded with a power ball (451), when the power wedge (45) moves close to the axis of the push rod ring (44), the power wedge (45) also moves close to the fixed shaft block (41), and the power ball (451) abuts against the fixed shaft block (41).

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