Impeller for a centrifugal blower with axial force balancing structure

Abstract

This invention provides an impeller for a centrifugal blower with an axial force balancing structure. It comprises a front disc, a rear disc, and blades, forming multiple airflow channels. An inlet sealing ring is fixed to the through hole in the center of the front disc, and a shaft disc is fixed to the through hole in the center of the rear disc. The shaft disc has an axial through hole in its center for connecting the main shaft. The shaft disc has an airflow balancing hole, which is an axially penetrating through hole. The side of the airflow balancing hole closest to the airflow channels is inclined outwards, forming an inclination angle with the through hole in the center of the shaft disc. By creating the airflow balancing hole on the shaft disc of this impeller, when the blower is running, the airflow entering the gap between the shaft disc and the return plate will flow back along the airflow balancing hole into the airflow channels inside the impeller and be discharged outwards with the normal airflow. This avoids axial impact on the bearings and shaft disc caused by this airflow, extending the service life of the blower. This invention can be widely applied to centrifugal blowers.

Description

Technical Field

[0001] This utility model relates to a centrifugal blower, and more particularly to an impeller for a centrifugal blower with an axial force balancing structure. Background Technology

[0002] Centrifugal blowers are devices that rely on the centrifugal force of impeller rotation to accelerate gas and convert it into pressure energy. They are widely used in gas transportation, industrial ventilation and other fields.

[0003] When a centrifugal blower is running, gas enters the impeller through the inlet volute. Under the centrifugal force of the rotating impeller, the airflow passes through the airflow channel inside the impeller and exits from the exhaust port at the outer circumference, entering the return channel and finally exiting through the exhaust volute. However, when the airflow exits from the impeller exhaust port, some airflow enters the gap between the shaft disc and the return plate. When the gas pressure in the gap is too high, it will cause axial impact on the bearings and shaft disc, causing the bearings and shaft disc to loosen and break, reducing the service life of the blower. Utility Model Content

[0004] This utility model addresses the above-mentioned technical problems by providing an impeller for a centrifugal blower with an axial force balancing structure. By opening a through hole on the shaft disc of the impeller, when the blower is running, the airflow entering the gap between the shaft disc and the return plate will flow back along the through hole to the airflow channel inside the impeller and be discharged outward with the normal air. This can prevent the airflow from staying in the gap between the shaft disc and the return plate, and will not cause axial impact to the bearings and shaft disc, thus extending the service life of the blower.

[0005] Therefore, the technical solution of this utility model is an impeller for a centrifugal blower with an axial force balancing structure, which is provided with a front plate and a rear plate, and a through hole is provided in the middle of the front plate and the rear plate respectively. Multiple blades are fixedly provided between the front plate and the rear plate. The multiple blades are arranged in the circumferential direction between the front plate and the rear plate. Multiple airflow channels are formed between the front plate, the rear plate and the blades. An air inlet and an air outlet are provided on the radial inner and outer sides of the airflow channels respectively.

[0006] An air inlet sealing ring is provided on the through hole in the middle of the front disc. The outer circumference of the air inlet sealing ring is fixedly connected to the inner circumference of the through hole. A shaft disc is provided on the through hole in the middle of the rear disc. The outer circumference of the shaft disc is fixedly connected to the inner circumference of the through hole. An axial through hole is provided in the middle of the shaft disc for fixed connection with the main shaft.

[0007] An airflow balance hole is provided on the outer side of the through hole on the shaft disk. The airflow balance hole is an axial through hole.

[0008] When the impeller is assembled into the centrifugal blower, there is a gap between the shaft disc and the return plate at the rear end of the shaft disc.

[0009] Preferably, the side of the airflow balance hole closest to the airflow channel is inclined outward, and forms an inclination angle with the through hole in the middle of the shaft disk, with an inclination angle of 30°±2°.

[0010] Preferably, the ratio between the diameter of the airflow balancing hole and the width of the gap between the shaft disk and the return plate at the rear end of the shaft disk is 1:2.

[0011] Preferably, the inner diameter of the airflow balancing hole is 30mm ± 3mm.

[0012] Preferably, there are multiple airflow balancing holes, which are evenly distributed along the circumferential direction on the outer side of the through holes on the shaft disk.

[0013] Preferably, the number of airflow balancing holes is eight.

[0014] Preferably, the shaft disk is provided with multiple mounting holes near the outer circumference. The multiple mounting holes are evenly distributed on the shaft disk along the circumferential direction. The multiple mounting holes and multiple airflow balance holes are staggered along the circumferential direction. The shaft disk and the rear disk are locked together by bolts passing through the mounting holes.

[0015] The beneficial effect of this utility model is that, by providing an airflow balance hole on the outer side of the through hole on the shaft disk, the airflow balance hole is an axially penetrating through hole. Simultaneously, the side of the airflow balance hole closest to the airflow channel is inclined outwards, forming an inclination angle of 30°±2° with the through hole in the middle of the shaft disk. When the blower is running, gas sequentially enters the airflow channel of the impeller from the inlet volute and the inlet. Under the centrifugal force of the rotating impeller, the gas flows along the airflow channel towards the outlet. At this time, most of the gas is discharged from the outlet and enters the return channel, subsequently entering... The gas enters the airflow channel of the next stage impeller and is eventually discharged outward through the exhaust volute. A small portion of the gas enters the gap between the rear plate and the adjacent return plate. At this time, the gas in the gap immediately flows back into the airflow channel of the impeller through the airflow balance hole and continues to flow towards the outlet with the airflow. The circulation and return of the gas in the gap can prevent excessive gas accumulation, which would lead to increased pressure and axial impact on the bearings and shaft, thus avoiding damage to the bearings and shaft, extending the service life of the blower, and reducing the operating noise of the blower. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of the structure of this utility model;

[0017] Figure 2 This is a cross-sectional view of the structure of this utility model applied to a centrifugal blower;

[0018] Figure 3 This is a plan view of the central shaft disk structure of this utility model;

[0019] Figure 4 This is a utility model Figure 2 Enlarged view of point A in the middle.

[0020] Explanation of symbols in the diagram:

[0021] 1. Front plate; 2. Rear plate; 3. Inlet seal ring; 4. Shaft plate; 5. Airflow balance hole; 6. Blade; 7. Inlet volute; 8. Exhaust volute; 9. Return plate; 10. Inlet; 11. Exhaust port; 12. Main shaft; 13. Assembly hole; 14. Return channel; 15. Gap. Detailed Implementation

[0022] The present invention will be further described below with reference to the embodiments.

[0023] pass Figures 1-4 As can be seen, the impeller of the centrifugal blower with axial force balancing structure is provided with a front plate 1 and a rear plate 2. The middle positions of the front plate 1 and the rear plate 2 are respectively provided with through holes. Multiple blades 6 are fixedly provided between the front plate 1 and the rear plate 2. The multiple blades 6 are arranged in the circumferential direction between the front plate 1 and the rear plate 2. Multiple airflow channels are formed between the front plate 1, the rear plate 2 and the blades 6. The radial inner side and the radial outer side of the airflow channels are respectively provided with an air inlet 10 and an air outlet 11.

[0024] An air inlet sealing ring 3 is provided on the through hole in the middle of the front disc 1. The outer circumference of the air inlet sealing ring 3 is fixedly connected to the inner circumference of the through hole. The air inlet sealing ring 3 is used to fixally connect to the air outlet of the air intake volute 7. A shaft disc 4 is provided on the through hole in the middle of the rear disc 2. The outer circumference of the shaft disc 4 is fixedly connected to the inner circumference of the through hole. An axial through hole is provided in the middle of the shaft disc 4 for fixing to the main shaft 12.

[0025] An airflow balance hole 5 is provided on the outer side of the through hole on the shaft disc 4. The airflow balance hole 5 is an axially penetrating through hole. When the blower is running, the gas enters the airflow channel of the impeller sequentially from the inlet volute 7 and the inlet 10. Under the centrifugal force of the impeller rotation, the gas flows along the airflow channel towards the outlet 11. At this time, most of the gas is discharged from the outlet 11 and enters the return channel 14, and then enters the airflow channel of the next stage impeller. Finally, it is discharged outward through the exhaust volute 8, while a small portion of the gas enters the rear disc 2 and the adjacent return channel behind it. In the gap between the flow plates 9, the gas in the gap will immediately flow back to the airflow channel of the impeller through the airflow balance hole 5, and continue to flow towards the outlet 11 with the airflow. Under the effect of the gas circulation in the gap, the axial force generated on the bearing and shaft is greatly reduced, and the pressure on both sides of the airflow balance hole 5 is balanced. This avoids excessive gas accumulation in the gap, which would lead to increased pressure and axial impact on the bearing and shaft, thus avoiding damage to the bearing and shaft, extending the service life of the blower, and reducing the operating noise of the blower.

[0026] After the impeller is assembled into the centrifugal blower, a gap 15 is provided between the shaft disc and the return plate at the rear end of the shaft disc to avoid friction when the impeller rotates.

[0027] In one specific embodiment, the airflow balancing hole 5 is inclined outward on the side near the airflow channel, and forms an inclined angle with the through hole in the middle of the shaft disk 4. Setting the airflow balancing hole 5 as an inclined hole can ensure the stability of the gas flow in this part, ensure that this part of the gas can smoothly enter the airflow channel, and will not cause a counter-impact on the normal airflow.

[0028] In one specific embodiment, the ratio between the diameter of the airflow balancing hole 5 and the width of the gap between the shaft disk 4 and the return plate 9 at the rear end of the shaft disk 4 is 1:2. This ratio is subject to strict standards during blower operation. If the diameter of the airflow balancing hole is too small when the gap width remains constant, the gas flowing back into the gap 15 cannot be discharged from the hole in time, causing continuous gas accumulation in the gap 15. The gap 15 remains under constant pressure, resulting in continuous axial impact on components such as bearings and shaft disks, reducing their service life. If the diameter of the airflow balancing hole is too large, the negative pressure at the airflow balancing hole will increase significantly during blower operation. Under the action of negative pressure, the amount of gas entering the gap 15 will increase significantly, affecting normal gas transmission, directly reducing gas transmission pressure, significantly reducing gas transmission efficiency, and increasing the noise of the blower during operation.

[0029] In one specific embodiment, the tilt angle is set to 30°±2°. This angle has a strict standard for the operation of the blower. If the tilt angle is too small, the gas in the airflow balance hole 5 will flow back and cause resistance to the normal gas flow at the air inlet 10, and a significant vortex will be formed at the air inlet 10, which will hinder the normal gas flow. If the tilt angle is too large, the radial dimension of the airflow balance hole 5 on the shaft disk 4 will be too large, which will damage the overall strength of the shaft disk 4.

[0030] In one specific embodiment, the inner diameter of the airflow balance hole 5 is 30mm ± 3mm. This hole diameter has strict standards. If the hole diameter is too large, it will interfere with the normal flow of gas in the airflow channel. If the hole diameter is too small, it will not be able to meet the rapid return flow of gas in the gap between the rear plate 2 and the return plate 9.

[0031] In one specific embodiment, there are multiple airflow balance holes 5, which are evenly distributed along the circumferential direction on the outer side of the through holes on the shaft disk 4. Without affecting the normal flow of gas in the airflow channel, the efficiency of gas return in the gap between the rear disk 2 and the return plate 9 is increased.

[0032] In one specific embodiment, the number of airflow balancing holes 5 is eight, which is the optimal number of airflow balancing holes 5, resulting in a significant gas recirculation effect.

[0033] In one specific embodiment, a plurality of mounting holes 13 are provided on the shaft disk 4 near the outer circumference. The plurality of mounting holes 13 are evenly distributed on the shaft disk 4 along the circumferential direction. The plurality of mounting holes 13 and the plurality of airflow balance holes 5 are staggered along the circumferential direction, which can ensure the structural strength of the shaft disk 4 and prevent the shaft disk 4 from bending under long-term rotation. The shaft disk 4 and the rear disk 2 are locked together by bolts passing through the mounting holes 13.

[0034] However, the above description is only a specific embodiment of this utility model and should not be construed as limiting the scope of implementation of this utility model. Therefore, any substitution of equivalent components or equivalent changes and modifications made in accordance with the scope of protection of this utility model should still fall within the scope of the claims of this utility model.

Claims

1. An impeller for a centrifugal blower with an axial force balancing structure, characterized in that: The device is provided with a front plate and a rear plate, and a through hole is provided in the middle of the front plate and the rear plate respectively. Multiple blades are fixedly provided between the front plate and the rear plate. The multiple blades are arranged in a circumferential direction between the front plate and the rear plate. Multiple airflow channels are formed between the front plate, the rear plate and the blades. An air inlet and an air outlet are provided on the radial inner and outer sides of the airflow channels respectively. An air inlet sealing ring is provided on the through hole in the middle of the front disc. The outer circumference of the air inlet sealing ring is fixedly connected to the inner circumference of the through hole. A shaft disc is provided on the through hole in the middle of the rear disc. The outer circumference of the shaft disc is fixedly connected to the inner circumference of the through hole. An axial through hole is provided in the middle of the shaft disc for fixed connection with the main shaft. An airflow balancing hole is provided on the outer side of the through hole on the shaft disk. The airflow balancing hole is an axially penetrating through hole. When the impeller is assembled into the centrifugal blower, a gap is provided between the shaft disk and the return plate at the rear end of the shaft disk.

2. The impeller for a centrifugal blower with an axial force balancing structure according to claim 1, characterized in that: The airflow balance hole is inclined outward on the side near the airflow channel, and forms an inclination angle with the through hole in the middle of the shaft disk, the inclination angle being 30°±2°.

3. The impeller for a centrifugal blower with an axial force balancing structure according to claim 2, characterized in that: The number of airflow balancing holes is multiple, and the multiple airflow balancing holes are evenly distributed along the circumferential direction on the outer side of the through holes on the shaft disk.

4. The impeller for a centrifugal blower with an axial force balancing structure according to claim 3, characterized in that: The number of airflow balancing holes is eight.

5. The impeller for a centrifugal blower with an axial force balancing structure according to claim 4, characterized in that: The ratio between the diameter of the airflow balancing hole and the width of the gap between the shaft disk and the return plate at the rear end of the shaft disk is 1:

2.

6. The impeller for a centrifugal blower with an axial force balancing structure according to claim 5, characterized in that: The inner diameter of the airflow balancing hole is 30mm ± 3mm.

7. The impeller for a centrifugal blower with an axial force balancing structure according to claim 6, characterized in that: The shaft disk is provided with multiple mounting holes near the outer circumference. The mounting holes are evenly distributed along the circumference on the shaft disk. The mounting holes and multiple airflow balance holes are staggered along the circumference. The shaft disk and the rear disk are locked together by bolts passing through the mounting holes.

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