Straight cylinder centrifugal ventilation fan

Abstract

The utility model discloses a straight tube centrifugal ventilation fan, which is characterized in that the outer diameter of a fan shell adopts a straight tube, when the straight tube centrifugal ventilation fan is assembled with a wall, the prefabricated aperture is reduced, the secondary filling area is reduced, and the risk of wall cracking or loosening can be reduced to a certain extent; and a motor is axially fixed in the fan shell. A flow guide plate is arranged at the air inlet end of the fan shell, the flow guide plate and the centrifugal fan blade set are arranged in an overlapped mode, and the purpose is to reduce operation wind resistance. An integrated flow guide arc plate is arranged at the air inlet end, close to the centrifugal fan blade set, of the fan shell, and mute guide resistance reduction of high-pressure airflow can be conducted; a negative pressure air inlet is formed between the flow guide arc plate and the fan shell, secondary flow guide can be achieved through the area, and the air volume can be increased; the fan blades are arranged in the centrifugal fan blade set, the sawtooth noise reduction structures are arranged at the ends, facing the air inlet, of the fan blades, airflow cutting is carried out through the sawtooth noise reduction structures in the low air pressure state, and large airflow noise on the rear side is avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of ventilation fans, and particularly relates to a straight-cylinder centrifugal ventilation fan. Background Art

[0002] In the technical field of wall ventilation fans, DC fans are more commonly used. However, the disadvantage of this type of fan when in use is that the wind pressure and wind speed are much lower than those of centrifugal fans under the parameters of the same model of fans. In order to increase the wind pressure and wind speed of the fan, technical personnel in this field intend to improve the exhaust efficiency by directly installing centrifugal fans. However, during the actual installation, it was found that the centrifugal fan is large in size and cannot be installed directly on the roof. Even if it is installed on the wall, a supporting part must be set up, and the installation cost is too high.

[0003] The present applicant discloses a centrifugal ventilation fan, the publication number of which is CN219317228U. The centrifugal ventilation fan sets the centrifugal fan blade group obliquely in the wind tube. In order to reduce the axial flow resistance, the present applicant thickens the middle part of the wind tube so that an arc-shaped guide cavity appears inside it. When the product is actually assembled, if it is installed on a wall, a fixing hole needs to be prefabricated on the wall. However, the diameter of the middle part of the wind tube of the fan is large, and the reserved hole must be processed according to the maximum aperture. When the centrifugal ventilation fan is installed, the centrifugal ventilation fan needs to be pushed into the prefabricated fixing hole for secondary filling. This installation method has a large workload and requires reinforcement. The filling area and the wall are secondary combined. When the fan is running, its vibration will cause the secondary joint to loosen or even leak. Furthermore, a guide plate is arranged inside the guide cavity of the centrifugal ventilation fan. The guide effect of this guide plate is better, but its setting position is the highest point of wind pressure. The airflow impacts the guide plate and noise occurs, affecting the surrounding environment.

[0004] In response to the two technical problems raised above, the applicant continued to make technical improvements on the product, with the aim of reducing the outer diameter of the fan duct and improving its installation efficiency by changing its internal flow guide structure without reducing wind pressure and wind speed, thereby reducing its operating noise. Summary of the invention

[0005] In view of the shortcomings of the prior art mentioned above, the utility model proposes a straight-cylinder centrifugal ventilation fan, which adopts a new fan structure, improves the guide structure inside the wind tube, and at the same time sets a wind resistance noise reduction structure in conjunction with the blades of the centrifugal fan blades, removes the existing guide plate arranged on the rear side of the centrifugal fan blade group, and reduces the operating noise without affecting the guide effect.

[0006] The technical solution adopted by the utility model to solve its technical problems is:

[0007] A straight-cylinder centrifugal ventilation fan, comprising a straight-cylinder fan housing, a motor is axially fixed inside the fan housing, a centrifugal blade group is arranged at the driving end of the motor, and the centrifugal blade group is arranged at an angle B with the axis of the motor; an integrated guide arc plate is arranged at the air inlet end of the fan housing near the centrifugal blade group, and a negative pressure air inlet is arranged between the guide arc plate and the fan housing;

[0008] A guide plate is arranged at the air inlet end of the fan housing, the guide plate and the centrifugal fan blade group are overlapped and a negative pressure chamber is arranged outside the two; the guide plate is tapered and a guide hole is arranged on its periphery; the guide hole, the negative pressure chamber and the negative pressure air inlet are connected;

[0009] The centrifugal fan blade group is provided with fan blades, and one end of the fan blade facing the air inlet is provided with a sawtooth noise reduction structure.

[0010] The centrifugal fan blade group includes a fan blade fixing seat, on which a fan blade inner layer plate is integrally arranged, the outside of the fan blade inner layer plate is a fan blade outer layer plate, a fan blade is arranged between the fan blade inner layer plate and the fan blade outer layer plate, an outer fixed edge is arranged on the outermost edge of the fan blade outer layer plate, and the outer fixed edge is radially arranged and perpendicular to the inner wall of the fan casing.

[0011] The integrated guide arc plate includes a guide arc surface and a right-angle mounting surface, the right-angle mounting surface is fixed to the inner wall of the fan housing, and the centrifugal fan blade group is locked to the right-angle mounting surface through an outer fixed edge.

[0012] A motor fixing cylinder is arranged inside the fan housing, and the motor fixing cylinder is fixed on the inner wall of the fan housing through a supporting arm. A motor supporting seat is arranged inside the motor fixing cylinder.

[0013] A motor support platform is arranged inside the fan housing, and the motor is fixed by the motor support platform.

[0014] A motor support rod is arranged inside the fan housing, and the motor is fixed by the motor support rod. This fixing method is a direct fixing method of the T35 fan.

[0015] The utility model has the following beneficial effects: through the above design, the utility model sets the outer diameter of the fan housing as a straight cylinder, which reduces the prefabricated aperture and the secondary filling area when assembled with the wall, and can reduce the risk of wall cracks or loosening to a certain extent; the motor is axially fixed inside the fan housing. A guide plate is arranged at the air inlet end of the fan housing, and the guide plate overlaps with the centrifugal blade group to reduce the running wind resistance; an integrated guide arc plate is arranged at the air inlet end of the fan housing near the centrifugal blade group, which can guide the high-pressure airflow silently and reduce the resistance; a negative pressure air inlet is arranged between the guide arc plate and the fan housing, and secondary guide can be achieved through this area to increase the air volume; a fan blade is arranged in the centrifugal blade group, and a sawtooth noise reduction structure is arranged at one end of the fan blade facing the air inlet, and the sawtooth noise reduction structure is used to cut the airflow under low wind pressure to avoid large airflow noise on the rear side. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0017] Figure 1 This is a schematic diagram of the rear end three-dimensional structure of the utility model;

[0018] Figure 2 This is a schematic diagram of the front-end three-dimensional structure of the utility model;

[0019] Figure 3 This is a schematic diagram of the internal cross-sectional structure of the utility model;

[0020] Figure 4 The utility model motor assembly structure diagram Figure Ⅰ ;

[0021] Figure 5 The utility model motor assembly structure diagram Figure II ;

[0022] Figure 6 The utility model motor assembly structure diagram Figure III ;

[0023] Figure 7 for Figure 3 A schematic diagram of the enlarged structure of the middle A area;

[0024] In the figure, 1. fan casing, 11. rear end flange, 12. lifting ring, 13. wire channel, 14. front end flange, 2. guide plate, 21. guide cone, 22. outer guide hole, 23. inner guide hole, 3. centrifugal fan blade group, 30. fan blade fixing seat, 31. fan blade inner plate, 32. fan blade, 33. fan blade outer plate, 34. outer fixed edge, 35. outer air flow hole, 36. noise reduction serration, 4. motor fixing cylinder, 41. motor support seat, 42. support arm, 43. motor support platform, 44. motor support rod, 5. negative pressure bin, 6. motor, 7. integrated guide arc plate, 71. guide arc surface, 72. right-angle mounting surface, 73. inner air flow hole, 8. negative pressure air inlet. DETAILED DESCRIPTION

[0025] The utility model is further described below through an implementation method. The following description is only one or several specific embodiments of the technical solution. Those skilled in the art may further make technical improvements based on the disclosure of the technical solution. If such improvements fully cover all technical features of the technical solution, they should fall within the scope of protection of this patent.

[0026] A straight-cylinder centrifugal ventilation fan, as shown in the attached drawings, includes a fan housing 1 of a rotating body straight-cylinder design, and a motor 6 is axially fixed inside the fan housing 1. The design focus of the utility model is that a centrifugal fan blade group 3 is arranged at the end of the motor 6, and the centrifugal fan blade group 3 is arranged at an angle B with the axis of the motor. The angle B is 35 to 50 degrees. In this embodiment, the angle B is 40 degrees. Because in this embodiment, the fan housing 1 is not equipped with a centrifugal fan blade group 3 to set an outward expansion guide device, it is necessary to require that the angle B between the centrifugal fan blade group 3 and the axis of the motor be smaller than the setting angle of the centrifugal fan blade group 3 in the prior art.

[0027] like Figure 3 As shown, the centrifugal fan blade group 3 includes a fan blade fixing seat 30, on which a fan blade inner layer plate 31 is integrally arranged, and the outside of the fan blade inner layer plate 31 is a fan blade outer layer plate 33, and a plurality of fan blades 32 are evenly distributed between the fan blade inner layer plate 31 and the fan blade outer layer plate 33. The high-speed rotating centrifugal fan blade group 3 is centrifugally guided outward, and the high-speed airflow enters the interior of the centrifugal fan blade group 3 and is guided to the rear end of the fan casing 1 after being pressurized.

[0028] The utility model removes the guide cavity used for guiding the flow in the prior art. This design makes the fan housing 1 equal in diameter. However, the technical problem brought about by the above modification is that if the airflow directly hits the fan housing 1, it will have a great impact on the wind pressure. The utility model improves the following design: an integrated guide arc plate 7 is provided at the air inlet end of the fan housing 1 near the centrifugal blade group 3, combined with Figure 3 and Figure 7 The integrated guide arc plate 7 includes a guide arc surface 71 and a right-angle mounting surface 72, which are an integrated structure formed by bending. The right-angle mounting surface 72 is welded and fixed to the inner wall of the fan casing 1, and a fixing hole is provided on the right-angle mounting surface 72. At this time, the right-angle mounting surface 72 can be used as an assembly flange; the utility model bends the outer edge of the blade outer layer plate 33 on the centrifugal fan blade group 3 to form an outer fixed edge 34, and the outer fixed edge 34 is radially arranged and perpendicular to the inner wall of the fan casing 1. The outer fixed edge 34 is also provided with a fixing hole, and the outer fixed edge 34 is fitted with the right-angle mounting surface 72 to achieve the locking of the centrifugal fan blade group 3 and the integrated guide arc plate 7. This design ensures the relative guide position between the centrifugal fan blade group 3 and the integrated guide arc plate 7, and at the same time eliminates the vibration phenomenon of the centrifugal fan blade group 3 when it runs independently at high speed.

[0029] Through the above design, the airflow centrifugally pressurized by the centrifugal fan blade group 3 is guided by the integrated guide arc plate 7 and transported to the rear side. After testing, the wind pressure of the utility model will not be attenuated by using the integrated guide arc plate 7 for guidance.

[0030] The utility model is provided with a guide plate 2 at the air inlet end of the fan housing 1, and the design is the same as the prior art structure in that the guide plate 2 is tapered and the guide plate 2 and the centrifugal blade group 3 are overlapped. Through the test of the prior art, it is found that if the guide arc surface 71 on the integrated guide arc plate 7 is not designed to fit the fan casing 1, that is, a negative pressure air inlet 8 is set between the two, according to the Venturi principle, a negative pressure bin 5 will appear between the guide plate 2 and the centrifugal fan blade group 3. The applicant sets an inner air flow through hole 73 on the right-angle mounting surface 72, and sets an outer air flow through hole 35 correspondingly on the outer fixed edge 34. Furthermore, guide holes are also set on the periphery of the guide plate 2. In the present embodiment, the guide holes are set to two layers, namely, the outer guide holes 22 and the inner guide holes 23. After the above structural design, the outer guide holes 22 and the inner guide holes 23, the inner air flow through holes 73 and the outer air flow through holes 35, the negative pressure bin 5 and the negative pressure air inlet 8 are all connected; when the centrifugal fan blade group 3 runs at high speed, the air flow can be sucked in for the second time through the negative pressure air inlet 8 to increase the air volume.

[0031] Because this type of centrifugal axial flow fan in the prior art has high power consumption and high operating speed, the airflow impacts the inside of the wind tube during operation to produce relatively large noise. The utility model combines the existing axial flow fan blade structure and provides noise reduction serrations 36 on the end of the fan blade 32 facing the air inlet. When the centrifugal fan blade group 3 runs at high speed, the noise reduction serrations 36 cut the airflow to achieve noise reduction. This structure has been systematically tested on the axial flow fan blades and has obvious noise reduction effects.

[0032] In this embodiment, a lifting ring 12 is provided on the outer wall of the fan housing 1 for lifting during installation. The rear end flange 11 and the front end flange 14 at the front and rear ends of the fan housing 1 are respectively used for locking and fixing with the wall. At the same time, the front end flange 14 is also used for locking and fixing the guide plate 2.

[0033] Based on the above structural arrangement, the utility model has the same structure as the existing ventilation fan internal fixed motor, this kind of motor fixing method has three ways, respectively as follows: Figure 4 , 5 6, the first type: a motor fixing cylinder 4 is arranged inside the fan housing 1, and the motor fixing cylinder 4 is fixed to the inner wall of the fan housing 1 through a support arm 42. A motor support seat 41 is arranged inside the motor fixing cylinder 4 for fixing the motor 6. To achieve wire access, a wire channel 13 extends from the outside of the fan housing 1 to the inside of the motor fixing cylinder 4, which can realize the extraction of the power line on the motor.

[0034] like Figure 5 As shown, the second motor fixing method: a motor support platform 43 is provided inside the fan housing 1, and the motor support platform 43 is welded and fixed to the inner wall of the fan housing 1, and the exposed assembly and fixation of the motor 6 is directly realized through the motor support platform 43.

[0035] like Figure 6 As shown, the third motor fixing method: a plurality of motor support rods 44 are arranged inside the fan housing 1, and the motor support rods 44 are welded and fixed to the inner wall of the fan housing 1, and the motor support platform 44 is directly locked with the bolts on the outer wall of the motor 6, thereby realizing the assembly and fixing of the motor 6. The setting details of this fixing method can refer to the fixing method of the T35 fan in the art.

[0036] Summary: Through the above design, the utility model combines and unifies the advantages of axial flow fans and centrifugal fans, and makes technical improvements. Under the design of equal-diameter fan housing 1, a motor 6 and a centrifugal blade group 3 are axially fixed inside the fan housing. By setting an integrated guide arc plate 7, not only the airflow is guided, but also a Venturi structure is formed together with the guide plate 2 and the centrifugal blade group 3, which can realize secondary suction of airflow and effectively increase the air volume of the fan. By designing the noise reduction sawtooth 36, when the centrifugal blade group 3 runs at high speed, the noise reduction effect is achieved by cutting the airflow through the noise reduction sawtooth 36, which not only overcomes the disadvantages of the prior art, but also improves the product performance. It is an ideal straight-cylinder centrifugal ventilation fan.

Claims

1. A straight centrifugal ventilation fan, characterized in that: It comprises a straight-cylindrical fan housing, a motor is axially fixed inside the fan housing, a centrifugal fan blade group is arranged at the driving end of the motor, and the centrifugal fan blade group is arranged at an angle of 35 to 50 degrees with the axis of the motor; an integrated guide arc plate is arranged at the air inlet end of the fan housing near the centrifugal fan blade group, and a negative pressure air inlet is arranged between the integrated guide arc plate and the fan housing; A guide plate is arranged at the air inlet end of the fan housing, the guide plate and the centrifugal fan blade group are overlapped and a negative pressure chamber is arranged outside the two; the guide plate is tapered and a guide hole is arranged on its periphery; the guide hole, the negative pressure chamber and the negative pressure air inlet are connected; The centrifugal fan blade group is provided with fan blades, and one end of the fan blade facing the air inlet is provided with a sawtooth noise reduction structure.

2. A straight-cylinder centrifugal ventilation fan according to claim 1, characterized in that: The centrifugal fan blade group includes a fan blade fixing seat, on which a fan blade inner layer plate is integrally arranged, the outside of the fan blade inner layer plate is a fan blade outer layer plate, a fan blade is arranged between the fan blade inner layer plate and the fan blade outer layer plate, an outer fixed edge is arranged on the outermost edge of the fan blade outer layer plate, and the outer fixed edge is radially arranged and perpendicular to the inner wall of the fan casing.

3. A straight-cylinder centrifugal ventilation fan as claimed in claim 2, characterized in that: The integrated guide arc plate includes a guide arc surface and a right-angle mounting surface, the right-angle mounting surface is fixed to the inner wall of the fan housing, and the centrifugal fan blade group is locked to the right-angle mounting surface through an outer fixed edge.

4. A straight-cylinder centrifugal ventilation fan as claimed in claim 1, characterized in that: A motor fixing cylinder is arranged inside the fan housing, and the motor fixing cylinder is fixed on the inner wall of the fan housing through a supporting arm.

5. A straight-cylinder centrifugal ventilation fan as claimed in claim 1, characterized in that: A motor support platform is arranged inside the fan housing, and the motor is fixed by the motor support platform.

6. A straight-cylinder centrifugal ventilation fan as claimed in claim 1, characterized in that: A motor support rod is arranged inside the fan housing, and the motor is fixed by the motor support rod.

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