Roof fan

Abstract

A roof fan comprises a base, a current collector is arranged on the base, a stand column is further arranged on the base, an air duct is arranged on the outer side of the stand column, the inner wall of the air duct is tangent to the stand column, and a sealing ring is arranged on the lower edge of the air duct and makes contact with the base. A rainproof cap, a fixing plate and a connecting piece are sequentially and fixedly connected to the upper end of the stand column, a motor is fixedly connected to the center of the fixing plate, a rotating shaft of the motor penetrates through a through hole formed in the center of the fixing plate, the rotating shaft of the motor is fixedly connected with an impeller, the connecting piece is an L-shaped connecting piece, and a vertical connecting foot of the connecting piece is fixedly connected with the protective cover. The lower edge of the protective cover is placed on the rainproof cap, the side face of the protective cover is connected with a waterproof connector through a hollow bolt, a top cover is arranged on the protective cover and movably connected with the protective cover, and the lower edge of the top cover is lower than the upper surface of the protective cover. The roof fan is convenient to assemble and disassemble, and oil stains on the inner surface of the rainproof cap cannot pollute the motor.

Description

Technical Field

[0001] This utility model belongs to the field of ventilation equipment technology, and in particular relates to a roof fan. Background Technology

[0002] In existing roof ventilators, the motor is typically installed inside the ventilator's casing, with a rain cap usually installed at the outlet. After prolonged operation, oil and other contaminants accumulate on the inner wall of the rain cap. Excessive oil buildup can drip onto the motor, affecting its cleanliness and potentially accelerating corrosion or causing malfunctions. Furthermore, installing the motor inside the ventilator necessitates disassembling the casing for maintenance and repair, which is extremely inconvenient. Utility Model Content

[0003] The main purpose of this invention is to solve the problems of easy contamination and inconvenient disassembly of the motor of roof ventilator.

[0004] This utility model provides a roof ventilator, including a base. The base is a hollow prism with a square bottom surface. The bottom surface of the base is open, and a circular opening is provided in the middle of the top surface. A collector is provided at the circular opening, and the lower edge of the collector is fixedly connected to the top surface of the base. The base is characterized in that a column is fixedly connected to the top surface of the base, and a hollow circular duct is provided on the outside of the column. The inner wall of the duct is tangent to the column, and a sealing ring is provided on the lower edge of the duct to seal the connection between the duct and the base.

[0005] A rain cap, a fixing plate, and a connector are fixedly connected to the upper end of the column in sequence. The inner diameter of the rain cap is larger than the outer diameter of the air duct, and the lower edge of the rain cap is lower than the upper edge of the air duct. A motor is fixedly connected to the center of the fixing plate. A through hole is opened at the position of the motor shaft on the fixing plate. The motor shaft passes through the through hole. An impeller is fixedly connected to the motor shaft. The impeller is inside the air duct.

[0006] The connector is an L-shaped connector. The horizontal connecting foot of the connector is fixedly connected to the column, and the vertical connecting foot of the connector is fixedly connected to the protective cover. The lower edge of the protective cover is placed on the rain cap. The side of the protective cover is connected to a waterproof joint by hollow bolts. A top cover is provided on the protective cover. The top cover is movably connected to the protective cover, and the lower edge of the top cover is lower than the upper surface of the protective cover.

[0007] Furthermore, the upper end of the protective cover is provided with a boss, and a latch lock is provided below the boss. The top of the latch lock can be rotated to the top of the boss. The lower edge of the top cover is placed on the boss of the protective cover. The lower edge of the top cover has a flange. The latch lock can be used to fasten the top cover to the lower edge of the top cover and lock the top cover on the protective cover. The top cover can be removed from the protective cover by releasing the latch lock.

[0008] Furthermore, a circular mesh cover is provided above the air duct, with the bottom surface of the mesh cover fitting against the top surface of the air duct, and the inner wall of the mesh cover being tangent to the column. The mesh cover is provided with mesh holes.

[0009] Furthermore, the rain cap is an annular thin-walled shell structure. The top surface of the rain cap is an annular plane, and the diameter of the rain cap gradually increases in a streamlined shape from the top edge downwards. The outer diameter of the lower edge of the rain cap is 1.2 to 2 times the outer diameter of the mesh cover.

[0010] Furthermore, the upper end of the column has a protruding threaded rod with an outer diameter smaller than that of the column. The rain cap, fixing plate, and connector each have through holes corresponding to the threaded rod. The diameter of the through hole on the rain cap is larger than the outer diameter of the threaded rod but smaller than that of the column. The rain cap, fixing plate, and connector are sequentially threaded through the threaded rod from bottom to top. A nut is provided on the threaded rod above the through hole of the connector. The nut fixes the rain cap, fixing plate, and connector to the threaded rod.

[0011] Furthermore, a bolt is provided on the top surface of the base, with the bolt head below the top surface of the base and the screw protruding above the top surface of the base. A column is fixedly connected to the screw of the bolt, and the lower end of the column has an internal thread. The screw on the bolt is fixedly connected to the lower end of the column by the thread.

[0012] Furthermore, the impeller is a backward-inclined centrifugal impeller, with the inner diameter at the lower end of the impeller being larger than the outer diameter of the collector, and the lower end of the impeller being lower than the top surface of the collector.

[0013] Furthermore, a capacitor box is also provided above the fixing plate. The capacitor box has lugs on both sides, which are connected to the fixing plate by bolts. The opening of the capacitor box faces downward. A capacitor and a terminal block are placed inside the capacitor box. The capacitor and the terminal block are electrically connected. The capacitor box has wire outlet holes at both ends. The capacitor wires extend outward through the wire outlet holes and connect to the motor wires. A wiring port is provided on the other side of the capacitor box. The power cord of the terminal block can pass through the wiring port and the waterproof connector on the side of the protective cover to connect to the power supply, so as to realize the speed regulation function of the roof fan.

[0014] The beneficial effects that this utility model can achieve are: the motor of this utility model is set in an independent cavity, the oil stains on the inner surface of the rain cap will not contaminate the motor, and the top cover and protective cover on the motor are movably connected, making the maintenance of the motor very convenient.

[0015] The roof fan of this invention is very easy to assemble and disassemble. It does not require welding or the application of waterproof glue. Assembly can be completed with only common tools such as wrenches and screwdrivers, which reduces the labor intensity of assembly personnel and improves the environmental friendliness of the assembly process.

[0016] The roof fan of this utility model uses a combination of a mesh cover and a rain cap. While protecting against rain and ensuring exhaust, the porous structure of the mesh cover can divide a large airflow into multiple smaller airflows, making the flow velocity distribution more uniform, reducing the generation of eddies, and thus reducing turbulent noise. The mesh cover can also prevent insects and birds from entering the fan and prevent people from touching the running impeller during maintenance, thus playing a role in safety protection. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of this utility model. Figure 1 .

[0018] Figure 2 This is a schematic diagram of the overall structure of this utility model. Figure 2 .

[0019] Figure 3 This is a cross-sectional view of the present invention.

[0020] Figure 4 This is a schematic diagram of the interior of this utility model. Figure 1 .

[0021] Figure 5 This is a schematic diagram of the interior of this utility model. Figure 2 .

[0022] Figure 6 This is a circuit diagram of the present invention.

[0023] Explanation of reference numerals in the attached diagram: 1. Base, 2. Mounting hole, 3. Collector, 4. Bolt, 5. Column, 6. Threaded rod, 7. Nut, 8. Air duct, 9. Sealing ring, 10. Mesh cover, 11. Rain cap, 12. Fixing plate, 13. Connector, 14. Motor, 15. Positioning plate, 16. Impeller, 17. Protective cover, 18. Hook and loop lock, 19. Top cover, 20. Capacitor box, 21. Support lug, 22. Cable outlet, 23. Waterproof connector. Detailed Implementation

[0024] To better understand the purpose, structure, and function of this utility model, a roof ventilator according to this utility model will be described in further detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described are only for explaining this utility model and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts relevant to this utility model are shown in the accompanying drawings, not the entire structure.

[0025] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or a connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0026] In this invention, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0027] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0028] like Figure 1-5 As shown, the roof ventilator of this utility model includes a base 1, which is a hollow prism with a square base. Mounting holes 2 are provided on the side of the base 1, into which conventional fixing components such as pins, rivets, and screws can be inserted to fix the base 1 to the roof. The bottom surface of the base 1 is open, and a circular opening is provided in the center of the top surface. A collector 3 is installed in the circular opening. The collector 3 is a flared structure with a small inner diameter at the top and a large inner diameter at the bottom. The upper edge of the collector 3 is above the base 1, and the lower edge is below the top surface of the base 1 and connected to the base 1 by bolts.

[0029] A bolt 4 is also provided on the top surface of the base 1. The head of the bolt 4 is below the top surface of the base 1, and the threaded rod 6 protrudes above the top surface of the base 1. A column 5 is fixedly connected to the threaded rod 6 of the bolt 4. The lower end of the column 5 is provided with an internal thread, and the column 5 and the external thread on the bolt 4 are fixedly connected by threads. The upper end of the column 5 has a protruding threaded rod 6, and the outer diameter of the threaded rod 6 is smaller than the outer diameter of the column 5. Other structures of the roof ventilator are provided above the threaded rod 6 of the column 5. For structural stability, the number of columns 5 should not be less than 3. In this embodiment, 4 columns 5 are provided.

[0030] A duct 8 is installed on the outer side of the support column 5, with its inner wall tangent to the four support columns 5. A sealing ring 9 is installed on the lower edge of the duct 8, which contacts the base 1 to seal the connection between the duct 8 and the base 1. A circular mesh cover 10 is installed above the duct 8, with its bottom surface fitting against the bottom surface of the duct 8. The inner wall of the mesh cover 10 is also tangent to the four support columns 5, and its bottom surface is located below the threaded rod 6 of the support column 5. The mesh cover 10 has mesh holes, and its porous structure can divide a large airflow into multiple smaller airflows, making the airflow velocity distribution more uniform, reducing eddy currents, and thus reducing turbulence noise. The mesh cover 10 also prevents insects and birds from entering the roof ventilator and prevents people from touching the rotating impeller during maintenance, providing safety protection.

[0031] A rain cap 11, a fixing plate 12, and a connector 13 are sequentially connected to the threaded rod 6 of the column 5. The rain cap 11 is an annular thin-walled shell structure. The top surface of the rain cap 11 is an annular plane with a through hole corresponding to the threaded rod 6 of the column 5. The diameter of the through hole is larger than the outer diameter of the threaded rod 6 but smaller than the outer diameter of the column 5. After the through hole on the top surface of the rain cap 11 passes through the threaded rod 6 of the column 5, the top surface stops at the lower end of the threaded rod 6 of the column 5. The diameter of the rain cap 11 gradually increases in a streamlined shape from the top edge downwards. In order to simultaneously consider airflow discharge and rain protection, the inner diameter of the lower edge of the rain cap 11 is set to be between 1.2 and 2 times the outer diameter of the mesh cover 10. In this embodiment, the inner diameter of the lower edge of the rain cap 11 is 1.5 times the outer diameter of the mesh cover 10. After the airflow is discharged from the mesh cover 10, it diffuses into the air outside the mesh cover 10 and will not be reflected back into the mesh cover 10 by the rain cap 11. The lower edge of the rain cap 11 is lower than the lower edge of the net cover 10, enclosing the net cover 10 inside the rain cap 11 to prevent rainwater from entering the roof fan and causing leaks.

[0032] A fixing plate 12 is placed on the rain cap 11. The fixing plate 12 has through holes corresponding to the threaded rod 6 of the column 5. The threaded rod 6 of the column 5 passes through the through holes in the fixing plate 12, fixing the fixing plate 12 to the column 5. A motor 14 is located at the center of the fixing plate 12. A positioning piece 15 is located at the lower end of the motor 14. The positioning piece 15 is bolted to the fixing plate 12, fixing the motor 14 to the fixing plate 12. A through hole is provided at the shaft position of the motor 14, through which the shaft of the motor 14 passes into the mesh cover 10. An impeller 16 is connected to the shaft of the motor 14. The impeller 16 is preferably a backward-inclined centrifugal impeller. The inner diameter of the lower end of the impeller 16 is slightly larger than the outer diameter of the collector 3, and the lower end of the impeller 16 is slightly lower than the upper top surface of the collector 3. When the motor 14 operates, it drives the impeller 16 to rotate, expelling the air inside the impeller 16. The air in the collector 3 forms an airflow that flows towards the impeller 16. The combination of collector 3 and impeller 16 allows the airflow to enter the impeller smoothly and orderly, reducing flow loss, increasing the flow range, and improving the impeller's working efficiency.

[0033] A capacitor box 20 is also provided above the fixing plate 12. Support ears 21 are provided on both sides of the capacitor box 20, and positioning holes are provided on the support ears 21. Bolts pass through the positioning holes on the support ears 21 and the corresponding through holes on the fixing plate 12 to fix the capacitor box 20 and the fixing plate 12. The capacitor box 20 faces downwards, and a capacitor and a terminal block are placed inside the capacitor box 20. The capacitor and the terminal block are electrically connected. Outlet holes 22 are provided at both ends of the capacitor box 20. The capacitor wires extend outwards through the outlet holes 22 and connect to the wires of the motor 14. A wiring port is provided on the other side of the capacitor box 20, through which the power cable of the terminal block can be connected to the power supply. The motor 14 is connected to the capacitor, the capacitor is connected to the terminal block, and the terminal block is connected to the power supply. The speed range is adjusted by switching the capacitor capacity through the terminal block, realizing the speed regulation function of the roof fan. Figure 6 The diagram shows a circuit for two-speed regulation. Multiple speed settings can also be achieved by increasing the number of taps on the motor. The capacitor box 20 and the capacitors and terminal blocks placed within it are the preferred embodiment of this invention, used to regulate the speed of the roof ventilator. Alternatively, without the capacitor box 20, capacitors, and terminal blocks, directly connecting the motor 14's wires to the power supply can also enable the roof ventilator to switch on and off, allowing it to operate normally.

[0034] The connector 13 is an L-shaped connector with through holes on both planes. The horizontal connecting foot is placed towards the center of the fixing plate 12. The through hole on the horizontal connecting foot is fitted onto the threaded rod 6 of the column 5 and fixed with the nut 7. The nut 7 fixes the rain cap 11, the fixing plate 12 and the connector 13 to the column 5.

[0035] A protective cover 17 is provided on the outer side of the connector 13. The protective cover 17 has positioning holes corresponding to the through holes on the vertical connecting feet of the connector 13. The positioning holes on the protective cover 17 are connected to the through holes on the vertical connecting feet of the connector 13 by bolts. A through hole is provided on the side of the protective cover 17, and a waterproof connector 23 is connected to the through hole by a hollow bolt. The power cord of the terminal block in the capacitor box 20 can pass through the waterproof connector 23 to connect to the power supply. The waterproof connector 23 can prevent rainwater from entering the protective cover 17.

[0036] The protective cover 17 has a boss at its upper end, and a latch 18 is located below the boss. The top of the latch 18 can be rotated to the top of the boss. The latch 18 is used to connect the protective cover 17 and the top cover 19 set on the protective cover 17. The top cover 19 is fitted over the protective cover 17, and the lower edge of the top cover 19 rests on the boss of the protective cover 17, which is lower than the upper surface of the protective cover 17. The lower edge of the top cover 19 has a flange. The connection between the top cover 19 and the protective cover 17 is achieved by using the latch 18 to fasten the top cover 19 to the flange of the lower edge of the top cover 19. The top cover 19 can be removed from the protective cover 17 by releasing the latch 18, so that the roof fan can be maintained and repaired.

[0037] During installation of the roof ventilator of this utility model, the collector 3 is first fixed to the base 1 with bolts. The column 5 is then screwed onto the bolts 4 on the base 1. The wind tunnel 8 and the mesh cover 10 are then sequentially fitted onto the outside of the column 5. The impeller 16 is placed between the columns 5, above the collector 3. A rain cap 11, a fixing plate 12, and a connector 13 are then fitted onto the threaded rod 6 on the column 5, and nuts 7 are screwed onto the threaded rod 6. The shaft of the motor 14 is rotated through the through hole in the center of the fixing plate 12, and bolts are used to pass through the positioning piece 15 and the corresponding through hole on the fixing plate 12 to fix the motor 14 to the fixing plate 12. The impeller 16 is lifted upwards from the bottom of the base 1, and the positioning hole in the center of the impeller 16 is aligned and passed through the shaft of the motor 14. A nut is added to the end of the shaft to fix the impeller 16 onto the shaft of the motor 14. The rotation of the shaft drives the impeller 16 to rotate.

[0038] After electrically connecting the capacitor and terminal block, install them into the capacitor box 20. The capacitor's wires pass through the outlet hole 22 and connect to the motor's wires. The terminal block's power cable passes through the outlet hole on the side of the capacitor box 20 and extends to the waterproof connector 23 of the protective cover 17. Place the protective cover 17 over the fixing plate 12, aligning the positioning holes on the protective cover 17 with the through holes on the vertical connecting feet of the connector 13, and connect them with bolts. Place the top cover 19 with its opening facing down on the protective cover 17, and fasten it to the lower edge of the top cover 19 using the latch lock 18. This completes the assembly of the roof fan.

[0039] When performing circuit repair or maintenance, simply unlock the latch 18 and remove the top cover 19 to perform the repair and maintenance.

[0040] This utility model of a roof ventilator features a motor housed within an independent cavity, preventing oil stains on the inner surface of the rain cap from contaminating the motor. Furthermore, the motor's top cover and protective shield are movably connected, making motor maintenance extremely convenient. Assembly and disassembly are also highly efficient, requiring no welding or waterproofing adhesive; only common tools such as wrenches and screwdrivers are needed, reducing labor intensity and improving the environmental friendliness of the assembly process. Additionally, the roof ventilator utilizes a combined design of a mesh cover and rain cap. While providing rain protection and ensuring proper ventilation, the mesh cover's porous structure divides large airflows into smaller streams, resulting in a more uniform flow velocity distribution, reduced eddy currents, and lower turbulence noise. The mesh cover also prevents insects and birds from entering the ventilator and protects the impeller from accidental contact during maintenance, providing enhanced safety.

[0041] It is understood that this utility model has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this utility model. Furthermore, under the teachings of this utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this utility model.

Claims

1. A roof ventilator, comprising a base (1), the base (1) being a hollow prism with a square base, the base (1) having an opening on its bottom surface and a circular opening in the center of its top surface, a collector (3) being disposed at the circular opening, the lower edge of the collector (3) being fixedly connected to the top surface of the base (1), characterized in that, The top surface of the base (1) is also provided with a column (5), and a hollow circular air duct (8) is provided on the outside of the column (5). The inner wall of the air duct (8) is tangent to the column (5), and a sealing ring (9) is provided on the lower edge of the air duct (8). The sealing ring (9) seals the connection between the air duct (8) and the base (1). The upper end of the column (5) is fixedly connected from bottom to top with a rain cap (11), a fixing plate (12) and a connector (13). The inner diameter of the rain cap (11) is larger than the outer diameter of the air duct (8). The lower edge of the rain cap (11) is lower than the upper edge of the air duct (8). The center of the fixing plate (12) is fixedly connected with a motor (14). The fixing plate (12) has a through hole at the position of the motor (14) shaft. The motor (14) shaft passes through the through hole. An impeller (16) is fixedly connected to the motor (14) shaft. The impeller (16) is inside the air duct (8). The connector (13) is an L-shaped connector. The horizontal connecting foot of the connector (13) is fixedly connected to the column (5), and the vertical connecting foot of the connector (13) is fixedly connected to the protective cover (17). The lower edge of the protective cover (17) is placed on the rain cap (11). The side of the protective cover (17) is connected to a waterproof connector (23) by hollow bolts. A top cover (19) is provided on the protective cover (17). The top cover (19) is movably connected to the protective cover (17). The lower edge of the top cover (19) is lower than the upper surface of the protective cover (17).

2. A roof ventilator according to claim 1, characterized in that, The upper end of the protective cover (17) is provided with a boss, and a latch (18) is provided below the boss. The top of the latch (18) can be rotated to the top of the boss. The lower edge of the top cover (19) is placed on the boss of the protective cover (17). The lower edge of the top cover (19) has a flange. The latch (18) can be used to latch the top cover (19) onto the lower edge of the top cover (19) and lock the top cover (19) onto the protective cover (17). The top cover (19) can be removed from the protective cover (17) by releasing the latch (18).

3. A roof ventilator according to claim 1, characterized in that, A mesh cover (10) is provided above the air duct (8). The bottom surface of the mesh cover (10) is in contact with the top surface of the air duct (8). The inner wall of the mesh cover (10) is tangent to the column (5). The mesh cover (10) has mesh holes.

4. A roof ventilator according to claim 3, characterized in that, The rain cap (11) is an annular thin-walled shell structure. The top surface of the rain cap (11) is an annular plane. The diameter of the rain cap (11) gradually increases in a streamlined shape from the top edge downwards. The inner diameter of the lower edge of the rain cap (11) is 1.2 to 2 times the outer diameter of the mesh cover (10).

5. A roof ventilator according to claim 1, characterized in that, The upper end of the column (5) has a protruding threaded rod (6). The outer diameter of the threaded rod (6) is smaller than the outer diameter of the column (5). The rain cap (11), the fixing plate (12) and the connector (13) are respectively provided with through holes corresponding to the threaded rod (6). The diameter of the through hole on the rain cap (11) is larger than the outer diameter of the threaded rod (6) and smaller than the outer diameter of the column (5). The threaded rod (6) is connected to the rain cap (11), the fixing plate (12) and the connector (13) in sequence from bottom to top. The threaded rod (6) is provided with a nut (7) above the through hole of the connector (13). The nut (7) fixes the rain cap (11), the fixing plate (12) and the connector (13) on the threaded rod (6).

6. A roof ventilator according to claim 5, characterized in that, The top surface of the base (1) is also provided with a bolt (4). The head of the bolt (4) is below the top surface of the base (1), and the screw of the bolt (4) protrudes from the top surface of the base (1). A column (5) is fixedly connected to the screw of the bolt (4). The lower end of the column (5) has an internal thread, and the bolt (4) and the lower end of the column (5) are fixedly connected by the thread.

7. A roof ventilator according to claim 1, characterized in that, The impeller (16) is a backward-inclined centrifugal impeller. The inner diameter of the lower end of the impeller (16) is greater than the outer diameter of the collector (3), and the lower end of the impeller (16) is lower than the top surface of the collector (3).

8. A roof ventilator according to any one of claims 1-7, characterized in that, A capacitor box (20) is also provided above the fixing plate (12). Support ears (21) are provided on both sides of the capacitor box (20). The support ears (21) are connected to the fixing plate (12) by bolts. The opening of the capacitor box (20) faces downward. A capacitor and a terminal block are placed inside the capacitor box (20). The capacitor and the terminal block are electrically connected. The capacitor box (20) has wire outlet holes (22) at both ends. The capacitor wires pass through the wire outlet holes (22) and extend outward to connect with the wires of the motor (14). A wiring port is provided on the other side of the capacitor box (20). The power cord of the terminal block can pass through the wiring port and the waterproof connector (23) on the side of the protective cover (17) to connect to the power supply, so as to realize the speed regulation function of the roof fan.

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