Industrial centrifugal fan with forced flow guide inner cavity structure

Abstract

The invention discloses an industrial centrifugal fan with a forced flow guide inner cavity structure, relates to the technical field of centrifugal fans, and aims to solve the problem that the performance effect of the centrifugal fan is reduced due to the fact that an impeller in the centrifugal fan in the prior art cannot be automatically cleaned. Cleaning liquid is introduced into the end of the rotating shaft through the cleaning tank on the transmission shell at regular time, the cleaning liquid is moved to be discharged into the surface of the impeller from the liquid discharging hole, and the cleaning liquid continuously impacts the surface of the impeller along with low-speed reverse rotation of the impeller, so that automatic washing of the impeller is completed; meanwhile, the wet impeller is prevented from being secondarily polluted by impurities in air in the rotating process, the rotating shaft rotates to drive the sleeve to rotate, the guide fan blades are closed at the front end of the machine shell, airflow inrush caused by rotation of the impeller is prevented, then automatic drying is conducted through high-speed rotation of the impeller, and automatic cleaning of the impeller is achieved when the centrifugal fan works.

Description

Technical Field

[0001] The invention relates to the technical field of centrifugal fans, in particular to an industrial centrifugal fan with a forced flow-guiding inner cavity structure. Background Art

[0002] Centrifugal fans are machines that rely on input mechanical energy to increase gas pressure and discharge gas. They are driven fluid machines. Centrifugal fans are widely used for ventilation, dust removal and cooling in factories, mines, tunnels, cooling towers, vehicles, ships and buildings. In a single-stage centrifugal fan, the gas enters the impeller from the axial direction, changes to radial direction when passing through the impeller, and then enters the diffuser. In the diffuser, the gas changes its flow direction and causes deceleration. This deceleration converts kinetic energy into pressure energy. The pressure increase mainly occurs in the impeller, and secondly in the expansion process. In a multi-stage centrifugal fan, a return flow device is used to allow the air flow to enter the next impeller, generating a higher pressure. Controlling the air volume of the centrifugal fan can not only make the effect of the centrifugal fan get the best performance, but also help users reduce energy consumption. There are several ways to adjust the air volume of the centrifugal fan, such as adjusting the size of the opening valve of the air inlet and outlet, adjusting the volute line shape, adjusting the size of the impeller blades, adjusting the impeller angle, adjusting the belt drive speed, or adjusting the power pole number of the drive motor, etc., and adjusting the flow rate by adjusting the opening and closing degree of the door can force the change of the direction of the airflow entering the shell, and with the rotation of the impeller, the gas can be discharged from the shell more quickly. At the same time, due to the different working environments of the centrifugal fan, the impeller needs to be shut down for cleaning after a long period of work. Common disassembly and wiping cleaning will be limited by the installation position and number of the centrifugal fan. Therefore, there is an urgent need for industrial centrifugal fans that can perform automatic impeller cleaning; To this end, we propose an industrial centrifugal fan with a forced flow guide inner cavity structure. Summary of the invention

[0003] The object of the present invention is to provide an industrial centrifugal fan with a forced flow guide inner cavity structure to solve the problem that the centrifugal fan proposed in the above background technology cannot adjust the air volume on the air inlet side and automatically clean the impeller inside the centrifugal fan, resulting in low performance of the centrifugal fan; To achieve the above object, the present invention provides the following technical solution: an industrial centrifugal fan with a forced flow guide inner cavity structure, comprising a base, a transmission shell is fixed to the top of the base by bolts, one side of the transmission shell is fixedly connected to the shell by spot welding, and an air outlet is opened on the top of the shell; A motor 1 is fixed to the top of the base by bolts, a pulley 1 is fixedly mounted on the output end of the motor 1, a rotating sleeve is movably connected in the transmission shell, an impeller is movably connected in the casing, one side of the rotating sleeve is fixed to the impeller by bolts, a pulley 2 is fixedly mounted on the rotating sleeve in the transmission shell, and a belt is installed on the pulley 2 on the rotating sleeve and the pulley on the motor 1.

[0004] Furthermore, an air collecting hood is slidably mounted inside the casing, and the air collecting hood is evenly provided with liquid leakage holes on the outer wall of the casing.

[0005] Furthermore, a trigger mechanism is installed in the transmission housing, and the trigger mechanism includes a rotating shaft, a water pipe and a drainage hole. A rotating shaft is slidably connected in the transmission housing and located in the rotating sleeve. The rotating shaft is hollow and one end is movably connected to the water pipe. One end of the rotating shaft passes through the rotating sleeve and is fixed to the inner wall of the air collecting hood by bolts. The rotating shaft is located on the outer wall of the impeller side and drainage holes are evenly opened.

[0006] Furthermore, the trigger mechanism also includes a baffle and a spring. The outer wall of the rotating shaft is movably connected with the baffle, and one side of the bottom of the baffle is slidably engaged with the inner wall of the transmission housing. The outer wall of the rotating shaft is sleeved with a spring, and one side of the spring is in contact with the transmission housing.

[0007] Furthermore, a motor 2 is fixed to the top of the transmission housing by bolts, the output end of the motor 2 passes through the transmission housing and is sleeved and fixed with a transmission tooth 1, the outer wall of the rotating shaft is sleeved with a gear sleeve in sliding connection, and one side of the gear sleeve is meshed with the transmission tooth 1, and a convex column is fixed to one side of the gear sleeve by spot welding, and one side of the convex column is in contact with a baffle.

[0008] Furthermore, the outer wall of the rotating shaft is slidably connected with a sleeve located inside the casing, the outer surface of the sleeve is evenly and movably connected with a guide blade, one side of the guide blade passes through the through hole on the wind collecting cover and extends into the casing, the guide blade is located on the inner and outer walls of the casing and is fixed with a transmission tooth 2, the inner wall of the casing is fixed with a gear ring by bolts, and the gear ring is meshingly connected with the transmission tooth 2.

[0009] Furthermore, a cleaning tank is fixed to one side of the transmission housing by bolts, one end of the water pipe passes through the transmission housing and is connected to the cleaning tank, and a solenoid valve is installed on the outside of the water pipe.

[0010] The working method of the industrial centrifugal fan with a forced flow guide inner cavity structure is: According to the working environment of the centrifugal fan, before starting, the motor 2 is used to drive the transmission gear 1 in the transmission housing to rotate counterclockwise by 30°, so that the gear sleeve drives the rotating shaft to rotate, and the sleeve on the rotating shaft drives the guide blades and the transmission gear 2 at the end of the guide blades to rotate in the housing. The transmission gear 2 contacts the gear ring on the inner wall of the housing to drive the guide blades to unfold. The maximum opening and closing angle of the guide blades is controlled at 45°. At this time, the motor 1 located on the base is started again, and the pulley 1 on the motor 1 drives the pulley 2 on the rotating sleeve in the transmission housing to rotate. The impeller at the end of the rotating sleeve starts to rotate at high speed, and the airflow is continuously discharged from the air outlet; To control the exhaust volume, the second motor rotates in the opposite direction to drive the shaft to reset, and the sleeve on the shaft and the guide blades on the sleeve rotate in the opposite direction, the opening and closing angle between the guide blades decreases, the air intake decreases, and the exhaust volume of the centrifugal fan decreases.

[0011] Compared with the prior art, the present invention has the following beneficial effects: 1. In the present invention, the rotation angle of the rotating shaft in the casing is adjusted by the rotation of the second motor on the transmission casing, and the guide blades movably connected to the sleeve on the rotating shaft and the sleeve surface, when the rotating shaft rotates, the second transmission tooth at the end of the guide blade contacts the gear ring on the inner wall of the casing and rotates automatically, completing the control of the deflection angle of the guide blade, thereby controlling the direction of the airflow in the casing when the impeller rotates, and improving the gas discharge rate; 2. In the present invention, cleaning liquid is regularly introduced into the end of the rotating shaft through the cleaning tank on the transmission housing, and the cleaning liquid is moved from the drainage hole to the surface of the impeller. As the impeller rotates in the opposite direction at a low speed, the cleaning liquid continuously impacts the surface of the impeller, thereby completing the automatic flushing of the impeller and preventing the secondary contamination of the wet impeller by impurities in the air during its rotation. The rotation of the rotating shaft drives the rotation of the sleeve, and the guide blades are closed at the front end of the casing to prevent the influx of airflow caused by the rotation of the impeller. Subsequently, the impeller is automatically dried by rotating at a high speed, thereby realizing automatic cleaning of the impeller when the centrifugal fan is working, without the need to disassemble the fan, and improving the working efficiency of the centrifugal fan. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the overall structure of an industrial centrifugal fan with a forced flow guide inner cavity structure of the present invention; Figure 2 It is a schematic diagram of the internal transmission structure of the industrial centrifugal fan with a forced flow guide inner cavity structure of the present invention; Figure 3 This is a schematic diagram of the impeller installation structure in the casing of the present invention; Figure 4 This is a schematic diagram of the structure of the air collecting cover extending outward from the casing of the present invention; Figure 5 This is a schematic diagram of the second connection structure of the transmission gear at the end of the guide blade of the present invention; Figure 6 It is a schematic diagram of the transmission structure of an industrial centrifugal fan with a forced flow guide inner cavity structure of the present invention.

[0013] In the figure: 1. base; 2. transmission housing; 3. motor 1; 4. motor 2; 5. housing; 6. air hood; 7. cleaning tank; 8. rotating sleeve; 9. impeller; 10. trigger mechanism; 101. rotating shaft; 102. baffle; 103. water pipe; 104. spring; 105. drainage hole; 11. gear sleeve; 12. transmission gear 1; 13. leakage hole; 14. sleeve; 15. guide blade; 16. transmission gear 2; 17. gear ring; 18. air outlet; 19. pulley 1; 20. pulley 2; 21. boss. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0015] See also Figure 1-6 , the present invention provides a technical solution: Embodiment 1: In a single-stage centrifugal fan, the gas enters the impeller 9 from the axial direction, changes to the radial direction when passing through the impeller 9, and then enters the diffuser. In the diffuser, the gas changes the flow direction to cause deceleration. This deceleration effect converts kinetic energy into pressure energy. The pressure increase mainly occurs in the impeller 9, and secondly occurs in the diffusion process. The air volume of a newly installed centrifugal fan will be too large. Usually, the flow rate is adjusted by changing the speed of the fan, or by adjusting the opening and closing degree of the door. The present invention is located at the front end of the centrifugal fan. The casing 5 is installed with a trigger mechanism 10, and multiple groups of guide blades 15 are installed on the trigger mechanism 10. The rotation of the rotating shaft 101 is used to realize the offset angle control of the guide blades 15, thereby forcibly changing the direction of the airflow sucked in after the impeller 9 rotates, thereby accelerating the gas to be discharged from the air outlet 18, and also facilitating the flow adjustment of the centrifugal fan; Different from the conventional outer shell design, the rotating shaft 101 of the trigger mechanism 10 is located in the transmission shell 2 behind the impeller 9, and the adjustment can be carried out more centrally without affecting the normal rotation of the impeller 9. Figure 2 As shown, the centrifugal fan adopts a belt drive mode, a pulley 19 is fixed on the output end of the motor 3 installed on the base 1, and a pulley 20 is fixed on the rotating sleeve 8 in the transmission housing 2. Figure 3 It can be understood that one end of the rotating sleeve 8 is located in the casing 5 and fixed to the impeller 9 by bolts, so the rotation of the motor 3 directly drives the impeller 9 to rotate; Considering the placement angle control of the front guide blade 15, a rotating shaft 101 is slidably connected in the rotating sleeve 8 in the transmission housing 2, and the rotating shaft 101 is hollow. A gear sleeve 11 is slidably connected on the rotating shaft 101 and located in the transmission housing 2, and a motor 2 4 is fixed on the top of the transmission housing 2. The motor 2 4 is located in the transmission housing 2 and is fixed with a transmission gear 12. The transmission gear 12 is meshed with the gear sleeve 11. The rotating shaft 101 is controlled to rotate in the transmission housing 2 by the motor 2 4. Figure 3 As shown, the front end of the rotating shaft 101 is connected to the air collecting cover 6 sliding in the casing 5, and a sleeve 14 is sleeved on the rotating shaft 101 for sliding connection, and the sleeve 14 is evenly and movably connected with the guide blade 15, and the middle axis end of the guide blade 15 passes through the through hole on the air collecting cover 6 and extends into the casing 5, and at the same time, the casing 5 is used to limit the transmission tooth 2 16 fixed to the middle axis end of the guide blade 15, so as to avoid the sliding of the guide blade 15 caused by the subsequent left and right movement of the rotating shaft 101, which affects the airflow control of the guide blade 15; like Figure 5 As shown, a gear ring 17 is fixed to the inner wall of the housing 5 by bolts, and the gear ring 17 is meshed and abutted with the second transmission tooth 16 on the guide blade 15. Therefore, when the rotating shaft 101 rotates a certain angle, the second transmission tooth 16 contacts the gear ring 17 to drive the guide blade 15 to rotate, thereby realizing the rotation and opening and closing of the combined guide blade 15; like Figure 2 As shown, a baffle 102 is also sleeved and slidably connected on the rotating shaft 101, and a side convexity is set on the baffle 102, and a convex column 21 is fixed on the back side of the gear sleeve 11 by spot welding. When the gear sleeve 11 rotates counterclockwise, the convex column 21 on the gear sleeve 11 does not contact the side convexity on the baffle 102, so it will not drive the rotating shaft 101 to move. The bottom of the baffle 102 is clamped with the inner wall of the transmission case 2, so it can only slide back and forth on the rotating shaft 101. When the gear sleeve 11 rotates clockwise, the convex column 21 at this time contacts the side convexity on the baffle 102, and the gear sleeve 11 itself is on the rotating shaft. 101 is abutted by the transmission tooth 12, and its position does not change, but the baffle 102 will push the shaft 101 to slide to the left, thereby driving the entire shaft 101 to move. For the reset movement of the shaft 101, whenever the shaft 101 moves, it will squeeze the sleeve spring 104, so the shaft 101 is pushed to reset by the spring 104. Therefore, when the conventional guide fan blade 15 is turned, only the fixed rotation of the shaft 101 is considered. At the same time, the rotation opening direction of the guide fan blade 15 can be known according to the position of the air outlet 18 on the casing 5.

[0016] Embodiment 2: Considering the working environment of the centrifugal fan, dust and impurities are more or less adsorbed on its impeller 9, and the common cleaning of the centrifugal fan adopts disassembly and cleaning, and dry assembly. However, for centrifugal fans in harsh environments, such as mine ventilation, the number of centrifugal fans installed and the disassembly process make it more difficult to clean them. Therefore, the centrifugal fan in the present invention can be automatically cleaned at regular intervals; A cleaning tank 7 is installed on the outer side of the transmission housing 2. Cleaning liquid is stored in the cleaning tank 7. When the centrifugal fan impeller 9 needs to be cleaned, the cleaning liquid in the cleaning tank 7 will enter the cavity of the rotating shaft 101 due to the opening of the solenoid valve on the water pipe 103. The cleaning liquid flows along the drainage hole 105 on the rotating shaft 101 and finally reaches the surface of the impeller 9. After the low-speed rotation of the rotating sleeve 8, the cleaning liquid continuously contacts the impeller 9. The rotation of the impeller 9 flushes the impeller 9, so that the dust adsorbed on its surface is dissolved in the cleaning liquid. To prevent the cleaning liquid from flowing out of the casing 5 at a faster rate and the wet impeller 9 from being contaminated by dust in the incoming air, the guide blades 15 on the sleeve 14 need to be closed to prevent the airflow from entering completely. At this time, the motor 2 4 drives the transmission gear 12 to rotate counterclockwise, and the rotation of the gear sleeve 11 causes the convex column 21 to contact the upper convex side of the baffle 102, thereby promoting the movement of the rotating shaft 101 during the rotation process. The wind collecting cover 6 connected to the front end of the rotating shaft 101 is also shown in FIG. Figure 4 As shown, the leftward movement causes the leakage hole 13 on the wind collecting cover 6 to open, at which time the guide blade 15 is closed, and the impeller 9 automatically completes the cleaning process during the low-speed rotation, and then the sewage is discharged from the leakage hole 13; Considering that the impeller 9 needs to be kept dry after cleaning, after the cleaning tank 7 stops discharging liquid, the clean sewage automatically flows out, and the impeller 9 is idle while the guide blades 15 are continuously closed. The high-speed reverse rotation of the impeller 9 generates a centrifugal force to continuously move the accumulated liquid to the front guide blades 15. Then, the impeller 9 is dried, and the reverse rotation of the rotating shaft 101 is used to close the leakage hole 13 on the wind collecting cover 6 and open the guide blades 15 on the rotating shaft 101, so that the centrifugal fan starts to work normally. By setting up an automatic cleaning mechanism for the impeller 9 and cooperating with the closed environment formed by the guide blades 15 and the casing 5, the impeller 9 can be automatically cleaned during the continuous flushing process and will not be secondary polluted by dust in the air. At the same time, the automatic discharge of clean sewage and the reverse rotation and drying of the impeller 9 prevent sewage from entering the external connecting pipe through the air outlet 18, thereby ensuring the subsequent efficient operation of the centrifugal fan.

[0017] Working principle of the present invention: According to the working environment of the centrifugal fan, before starting, the motor 24 drives the transmission gear 12 in the transmission housing 2 to rotate 30° counterclockwise, so that the gear sleeve 11 drives the rotating shaft 101 to rotate, and the sleeve 14 on the rotating shaft 101 drives the guide blades 15 and the transmission gear 2 16 at the end of the guide blades 15 to rotate in the casing 5, and the transmission gear 2 16 contacts the gear ring 17 on the inner wall of the casing 5 to drive the guide blades 15 to unfold. At this time, the maximum opening and closing angle of the guide blades 15 is controlled at 45°. At this time, the motor 13 on the base 1 is started again, and the pulley 19 on the motor 13 drives the pulley 20 on the rotating sleeve 8 in the transmission housing 2 to rotate, and the impeller 9 at the end of the rotating sleeve 8 starts to rotate at a high speed, and the airflow is continuously discharged from the air outlet 18; To control the exhaust volume, the motor 24 rotates in the reverse direction to drive the shaft 101 to reset, and the sleeve 14 on the shaft 101 and the guide blades 15 on the sleeve 14 rotate in the reverse direction, the opening and closing angle between the guide blades 15 decreases, the air intake decreases, and the exhaust volume of the centrifugal fan decreases; When the motor 24 continues to rotate in the reverse direction, the boss 21 on the gear sleeve 11 contacts the baffle 102 on the shaft 101, pushing the baffle 102 to slide the shaft 101, thereby causing the guide blades 15 on the sleeve 14 to fully close, and the air intake of the entire centrifugal fan is blocked.

[0018] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

[0019] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0020] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. An industrial centrifugal fan with a forced flow guide inner cavity structure, comprising a base (1), characterized in that: A transmission housing (2) is fixed to the top of the machine base (1) by bolts, one side of the transmission housing (2) is fixedly connected to a machine housing (5) by spot welding, and an air outlet (18) is provided on the top of the machine housing (5); A motor (3) is fixed to the top of the base (1) by bolts, a pulley (19) is sleeved and fixed on the output end of the motor (3), a rotating sleeve (8) is movably connected to the transmission housing (2), an impeller (9) is movably connected to the housing (5), one side of the rotating sleeve (8) is fixed to the impeller (9) by bolts, the rotating sleeve (8) is located in the transmission housing (2) and sleeved and fixed with a pulley (20), and a belt is sleeved and installed between the pulley (20) on the rotating sleeve (8) and the pulley (19) on the motor (3).

2. The industrial centrifugal fan with a forced flow guide inner cavity structure according to claim 1, characterized in that: An air collecting hood (6) is slidably mounted inside the casing (5), and the air collecting hood (6) is located on an outer wall of a side of the casing (5) and is evenly provided with liquid leakage holes (13).

3. The industrial centrifugal fan with a forced flow guide inner cavity structure according to claim 2, characterized in that: A trigger mechanism (10) is installed in the transmission housing (2), and the trigger mechanism (10) comprises a rotating shaft (101), a water pipe (103) and a drainage hole (105). A rotating shaft (101) is slidably connected in the transmission housing (2) and located in the rotating sleeve (8). The rotating shaft (101) is hollow and one end of the rotating shaft is movably connected to the water pipe (103). One end of the rotating shaft (101) passes through the rotating sleeve (8) and is fixed to the inner wall of the air collecting cover (6) by bolts. The outer wall of the rotating shaft (101) located on the side of the impeller (9) is evenly provided with drainage holes (105).

4. The industrial centrifugal fan with a forced flow guide inner cavity structure according to claim 3, characterized in that: The trigger mechanism (10) further comprises a baffle (102) and a spring (104); the baffle (102) is sleeved and movably connected to the outer wall of the rotating shaft (101); one side of the bottom of the baffle (102) is slidably engaged with the inner wall of the transmission housing (2); the spring (104) is sleeved and installed on the outer wall of the rotating shaft (101); one side of the spring (104) is in contact with the transmission housing (2).

5. The industrial centrifugal fan with a forced flow guide inner cavity structure according to claim 4, characterized in that: A second motor (4) is fixed to the top of the transmission housing (2) by means of bolts; an output end of the second motor (4) passes through the transmission housing (2) and is sleeved and fixed with a first transmission tooth (12); a gear sleeve (11) is sleeved and slidably connected to the outer wall of the rotating shaft (101); one side of the gear sleeve (11) is meshedly connected to the first transmission tooth (12); a convex column (21) is fixed to one side of the gear sleeve (11) by means of spot welding; and one side of the convex column (21) is in contact with a baffle (102).

6. The industrial centrifugal fan with a forced flow guide inner cavity structure according to claim 5, characterized in that: The outer wall of the rotating shaft (101) is sleeved and slidably connected with a sleeve (14) located in the casing (5); the outer surface of the sleeve (14) is evenly and movably connected with a guide blade (15); one side of the guide blade (15) passes through a through hole on the wind collecting cover (6) and extends into the casing (5); the guide blade (15) is sleeved and fixed with a second transmission tooth (16) located on the inner and outer walls of the casing (5); a gear ring (17) is fixed to the inner wall of the casing (5) by bolts, and the gear ring (17) is meshingly connected with the second transmission tooth (16).

7. The industrial centrifugal fan with a forced flow guide inner cavity structure according to claim 6, characterized in that: A cleaning tank (7) is fixed to one side of the transmission housing (2) by means of bolts, one end of the water pipe (103) passes through the transmission housing (2) and is connected to the cleaning tank (7), and a solenoid valve is installed on the outside of the water pipe (103).

8. The industrial centrifugal fan with a forced flow guide inner cavity structure according to claim 7, characterized in that: The working method of the industrial centrifugal fan with a forced flow guide inner cavity structure is: According to the working environment of the centrifugal fan, before starting, the motor 2 (4) drives the transmission tooth 1 (12) in the transmission housing (2) to rotate counterclockwise by 30 degrees, so that the gear sleeve (11) drives the rotating shaft (101) to rotate, and the sleeve (14) on the rotating shaft (101) drives the guide blade (15) and the transmission tooth 2 (16) at the end of the guide blade (15) to rotate in the casing (5). The transmission tooth 2 (16) contacts the gear ring (17) on the inner wall of the casing (5) to drive the guide blade (15) to unfold, and the maximum opening and closing angle of the guide blade (15) is controlled at 45 degrees. At this time, the motor 1 (3) on the base (1) is started again, and the pulley 1 (19) on the motor 1 (3) drives the pulley 2 (20) on the rotating sleeve (8) in the transmission housing (2) to rotate, and the impeller (9) at the end of the rotating sleeve (8) starts to rotate at a high speed, and the airflow is continuously discharged from the air outlet (18); To control the exhaust volume, the second motor (4) rotates in the opposite direction to drive the rotating shaft (101) to reset, so that the sleeve (14) located on the rotating shaft (101) and the guide blades (15) on the sleeve (14) rotate in the opposite direction, the opening and closing angle between the guide blades (15) decreases, the air intake volume decreases, and the exhaust volume of the centrifugal fan decreases.

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