Method for dynamic balancing of an impeller for a centrifugal blower

Abstract

The application provides a dynamic balance adjusting method for an impeller of a centrifugal blower, wherein the impeller is provided with a front disc and a rear disc, a plurality of dynamic balance adjusting pieces are arranged at the outer circumferential position of the outer end of the front disc and are uniformly distributed along the circumferential direction of the front disc, and a plurality of dynamic balance adjusting pieces are arranged at the outer circumferential position of the outer end of the rear disc and are uniformly distributed along the circumferential direction of the rear disc. The outer circumferential end faces of the front disc and the rear disc of the impeller are respectively provided with a plurality of dynamic balance adjusting pieces. During the dynamic balance adjustment of the impeller, only the dynamic balance adjusting pieces at the specified positions need to be polished and removed, and the front disc and the rear disc are not damaged by polishing, so that the structural strength of the front disc and the rear disc is not damaged. The application can be widely applied to centrifugal blowers.

Description

Technical Field

[0001] This invention relates to an impeller, and more particularly to a method for dynamic balancing of an impeller for a centrifugal blower. Background Technology

[0002] Before assembly, the impellers in centrifugal blowers need to undergo dynamic balancing to eliminate or minimize the imbalance of centrifugal force caused by uneven impeller mass distribution, thereby ensuring that the blower can operate smoothly, efficiently, safely, and for a long time.

[0003] Currently, most impeller dynamic balancing methods employ the weight removal method, which involves grinding and removing weight from a specified end face position on the outer circumference of the front or rear disc of the impeller. This counteracts the imbalance of centrifugal force generated at that position during rotation, ultimately aligning the impeller's composite center of mass with the axis of rotation and achieving stable operation.

[0004] However, this weight-reduction method directly damages the structural strength of the front or rear disc, reduces its service life, and causes the outer circumference of the front or rear disc to become significantly thinner after grinding. When the impeller rotates, the outer circumference of the impeller will vibrate to varying degrees, resulting in eddies at the impeller outlet and increased blower noise.

[0005] Meanwhile, some of the gas passing through the impeller outlet will enter the gap between the impeller and the return guide plates on both sides. If the gas in the gap is not discharged in time, it will cause axial impact on the impeller. Under long-term impact, the impeller will also vibrate to varying degrees, reducing the impeller's operational stability. Summary of the Invention

[0006] To address the above-mentioned technical problems, this invention provides a method for dynamic balancing of an impeller for a centrifugal blower. The impeller's front and rear discs are each provided with multiple dynamic balancing plates on their outer circumferential end faces. During the impeller's dynamic balancing adjustment process, only the dynamic balancing plates at designated positions need to be ground to remove weight, without damaging the front and rear discs. This avoids compromising the structural strength of the front or rear discs and prevents impeller rotational vibration. Furthermore, when the impeller rotates, under the centrifugal force of the dynamic balancing plates, the gas entering the gap between the impeller and the return guide plates on both sides is quickly discharged, preventing axial impact on the impeller.

[0007] Therefore, the technical solution of the present invention is a method for dynamic balancing of an impeller for a centrifugal blower, comprising the following steps:

[0008] Step (1): Prepare the impeller and select multiple dynamic balancing plates of appropriate size according to the outer diameter of the impeller;

[0009] Step (2): Weld and fix multiple dynamic balance adjustment plates to the outermost radial position of the outer end face of the front plate and the rear plate respectively, and the multiple dynamic balance adjustment plates are evenly distributed along the circumferential direction on the front plate and the rear plate respectively.

[0010] Step (3): Install the impeller with the welded dynamic balancing adjustment plate onto the balancing machine for dynamic balancing test;

[0011] Step (4): According to the phase angle indicated by the balancing equipment, find the dynamic balancing adjustment plates that need to be de-weighted on the front and rear discs of the impeller respectively, and grind the dynamic balancing adjustment plates that need to be de-weighted to remove the weight.

[0012] Step (5): After grinding and removing weight, perform dynamic balancing retest on the impeller and determine whether the required balance accuracy is achieved based on the new measurement results;

[0013] Step (6): When the imbalance is less than the set tolerance range, the dynamic balancing adjustment is completed, and the impeller can be installed and used normally at this time;

[0014] Step (7): When the imbalance is greater than the set tolerance range, it is necessary to repeat steps (3)-(5) until the imbalance is less than the set tolerance range, and finally complete the dynamic balance adjustment.

[0015] Preferably, in step (4), during the process of grinding and removing weight from the dynamic balance adjustment plate, the thickness of the inner side of the dynamic balance adjustment plate after grinding should not be greater than the thickness of the outer side. This can significantly reduce the amount of gas entering the gap between the front and rear discs and the return guide plate, and ensure the smooth discharge of gas from the gap.

[0016] Preferably, the impeller used in the above dynamic balancing adjustment method has a front plate and a rear plate, with through holes in the middle of the front plate and the rear plate respectively, and multiple blades fixed between the front plate and the rear plate, with the multiple blades arranged circumferentially between the front plate and the rear plate.

[0017] An air inlet sealing ring is fixedly installed on the inner circumference of the through hole in the middle of the front disc, and a shaft disc is fixedly installed on the inner circumference of the through hole in the middle of the rear disc, with an axial through hole in the middle of the shaft disc.

[0018] Multiple airflow channels are formed between the front plate, rear plate, and axle plate, with air inlets and outlets respectively located on the radial inner and outer sides of the airflow channels;

[0019] Multiple dynamic balance adjustment plates are provided on the outer circumference of the outer end of the front disc, and the multiple dynamic balance adjustment plates are evenly distributed along the circumference of the front disc.

[0020] Multiple dynamic balance adjustment plates are provided on the outer circumference of the outer end of the rear plate, and the multiple dynamic balance adjustment plates are evenly distributed along the circumference of the rear plate.

[0021] Preferably, the dynamic balance adjustment plates on the front and rear discs are blade-shaped.

[0022] Preferably, the thickness of the dynamic balance adjustment plates on the front and rear discs is 8mm ± 1mm.

[0023] Preferably, the radial width of the dynamic balance adjustment plates on the front and rear discs is 110mm ± 5mm.

[0024] Preferably, the ratio between the radial width of the dynamic balance adjustment plate and the corresponding radii of the front and rear discs is 1:10.

[0025] Preferably, the number of dynamic balance adjustment plates on both the front and rear discs is twelve.

[0026] Preferably, the radially outer positions of the dynamic balance adjustment plates on the front and rear plates are chamfered;

[0027] The radial inner side of the dynamic balance adjustment plates on the front and rear discs is provided with an arc surface.

[0028] Preferably, the dynamic balance adjustment plates on the front and rear discs are provided with airflow guiding arc surfaces 503 on both sides of the circumference, and the radius of the airflow guiding arc surfaces is 59mm±2mm.

[0029] Preferably, multiple dynamic balance adjustment plates are fixed to the front plate and the rear plate by welding, respectively.

[0030] The beneficial effect of the present invention is that by providing multiple dynamic balance adjustment plates at the outer circumference of the outer end of the front disc, and the multiple dynamic balance adjustment plates are evenly distributed along the circumference of the front disc, and by providing multiple dynamic balance adjustment plates at the outer circumference of the outer end of the rear disc, the multiple dynamic balance adjustment plates are evenly distributed along the circumference of the rear disc, during the dynamic balancing adjustment of the impeller, only the dynamic balance adjustment plates at the designated positions need to be ground to remove weight, without causing grinding damage to the front and rear discs, and without damaging the structural strength of the front or rear discs, thus avoiding the problem of impeller rotational vibration;

[0031] Furthermore, after the impeller is assembled, the thickness of the balance adjustment plate can reduce the gap between the front and rear discs and the return guide plates on both sides, thereby reducing the amount of gas entering the gap when the impeller rotates. This prevents the gas pressure in the gap from being too high, which could cause axial impact on the impeller and affect the impeller's rotational stability.

[0032] Meanwhile, when a small amount of gas enters the gap, it will be rapidly discharged outward along the gap between two adjacent balance adjustment plates under the action of centrifugal force of impeller rotation. If there are no balance adjustment plates on the outer side of the front and rear discs, the airflow will be more dispersed when discharged, forming an irregular airflow. This will also cause irregular impacts on the impeller and return guide plate. Furthermore, the irregular airflow direction will affect the flow of normal gas discharged from the outlet, causing interference and ultimately affecting the overall airflow transmission guidance. Attached Figure Description

[0033] Figure 1 This is a cross-sectional view of the structure of the present invention;

[0034] Figure 2 This is the present invention. Figure 1 Schematic diagram of the A-axis structure and impeller rotation direction;

[0035] Figure 3 This is a schematic diagram of the structural principle of the present invention applied to a centrifugal blower;

[0036] Figure 4 This is the present invention. Figure 1 Enlarged view at point B in the middle;

[0037] Figure 5 This is the present invention. Figure 3 Schematic diagram of the C-axis structure;

[0038] Figure 6 This is the present invention. Figure 5 Enlarged view at point D;

[0039] Figure 7 This is the present invention. Figure 2 Enlarged view of point E in the middle.

[0040] Explanation of symbols in the diagram:

[0041] 1. Front plate; 2. Rear plate; 3. Inlet seal ring; 4. Shaft plate; 5. Dynamic balance adjustment plate; 501. Chamfer; 502. Arc surface; 503. Airflow guide arc surface; 6. Outlet; 7. Blade; 8. Airflow channel; 9. Inlet; 10. Inlet volute; 11. Return guide plate. Detailed Implementation

[0042] The present invention will be further described below with reference to embodiments.

[0043] pass Figures 1-7 It can be seen that the impeller of the centrifugal blower with dynamic balance adjustment device is provided with a front plate 1 and a rear plate 2. The middle position of the front plate 1 and the rear plate 2 is provided with through holes respectively. Multiple blades 7 are fixed between the front plate 1 and the rear plate 2. The multiple blades 7 are arranged in the circumferential direction between the front plate 1 and the rear plate 2.

[0044] An air inlet sealing ring 3 is fixedly installed on the inner circumference of the through hole in the middle of the front disc 1, and a shaft disc 4 is fixedly installed on the inner circumference of the through hole in the middle of the rear disc 2. An axial through hole is provided in the middle of the shaft disc 4. Multiple airflow channels 8 are formed between the front disc 1, the rear disc 2 and the shaft disc 4. An air inlet 9 and an air outlet 6 are respectively provided on the radial inner and outer sides of the airflow channels 8. When the fan is running, the gas enters through the air inlet 9, flows outward along the airflow channel 8 under the action of centrifugal force, and finally exits through the air outlet 6 to enter the next airflow channel, thereby realizing the transmission of gas.

[0045] Multiple dynamic balancing plates 5 are provided on the outer circumference of the outer end of the front disc 1, and are evenly distributed along the circumference of the front disc 1. Similarly, multiple dynamic balancing plates 5 are provided on the outer circumference of the outer end of the rear disc 2, and are also evenly distributed along the circumference of the rear disc 2. This allows for easy dynamic balancing adjustments during impeller operation, requiring only the dynamic balancing plates 5 at designated locations to be ground to reduce weight. This avoids damaging the front and rear discs during grinding, preserving their structural strength and preventing impeller vibration during rotation.

[0046] Furthermore, after the impeller is assembled, the thickness of the balance adjustment plate 5 can reduce the gap between the front and rear discs and the return guide plates 11 on both sides, thereby reducing the amount of gas entering the gap when the impeller rotates and preventing excessive gas pressure in the gap from causing axial impact on the impeller and affecting the impeller's rotational stability.

[0047] Most importantly, when a small amount of gas enters the gap, it will be rapidly concentrated and discharged outward along the gap between two adjacent balance adjustment plates 5 under the action of centrifugal force of impeller rotation. If there are no balance adjustment plates 5 on the outer side of the front and rear discs, the airflow will be more dispersed when discharged, forming an irregular airflow. This will also cause irregular impacts on the impeller and return guide plate 11. Furthermore, the irregular airflow direction will affect the flow of normal gas discharged from the outlet 6, causing interference and ultimately affecting the overall airflow transmission guidance.

[0048] In one specific embodiment, the dynamic balance adjustment plates 5 on the front disc 1 and the rear disc 2 are blade-shaped, and, through... Figure 2 It can be seen that the blade-shaped dynamic balancing adjustment plate 5 is arranged in the same direction as the impeller rotation direction, which can reduce the resistance when the impeller rotates and also play an auxiliary guiding role in the airflow.

[0049] In a specific embodiment, the thickness of the dynamic balancing adjustment plate 5 on the front plate 1 and the rear plate 2 is 8mm ± 1mm. This thickness is within a reasonable range. If the thickness is too thick, the gap between the dynamic balancing adjustment plate 5 and the return guide plate 11 will be too small. When the impeller rotates for a long time, slight shaking will inevitably occur. If the gap is too small, the dynamic balancing adjustment plate 5 and the return guide plate 11 will come into contact and rub against each other, causing damage to the impeller and the return guide plate 11. In addition, if the gap is too small, it will increase the operating noise. If the thickness is too thin, it will not meet the thickness requirements for grinding and weight removal during dynamic balancing. At the same time, if the thickness is too thin, it will lose the function of concentrating and directionally discharging the gas in the gap between the front and rear plates and the return guide plate 11. The airflow will also be relatively dispersed when it is discharged, forming an irregular airflow, which will cause irregular impacts on the impeller and the return guide plate 11.

[0050] In one specific embodiment, the radial width of the dynamic balance adjustment plate 5 on the front plate 1 and the rear plate 2 is 110mm ± 5mm. This radial width is the size required by commonly used centrifugal blowers, and can also be customized according to actual needs.

[0051] The ratio between the radial width of the dynamic balancing adjustment plate 5 and the corresponding radii of the front disc 1 and rear disc 2 is 1:10. This ratio has a strict standard. If the ratio is too large, it has been found through experiments that if the ratio is too large, it is sometimes necessary to weld a separate dynamic balancing adjustment plate 5 on the inner side of a certain dynamic balancing adjustment plate 5 and then grind it. The operation is complicated and cumbersome, and it defeats the purpose of this patent design. If the ratio is too small, it will increase the impeller rotation load and increase the resistance, especially when the impeller starts and stops, which is most obvious and reduces the impeller's service life.

[0052] In one specific embodiment, the number of dynamic balancing adjustment plates 5 on both the front plate 1 and the rear plate 2 is twelve, which is sufficient to meet the weight reduction angle requirements during most impeller dynamic balancing grinding.

[0053] In a specific embodiment, the dynamic balance adjustment plate 5 on the front plate 1 and the rear plate 2 is provided with a chamfer 501 on its radially outer side. When the dynamic balance adjustment plate 5 guides the gas in the gap between the front and rear plates and the return guide plate 11 to be discharged, under the guiding action of the chamfer 501, this part of the airflow will be guided to the middle position outside the air outlet 6, and converge with the normal transmission airflow to form a normal transmission airflow. It will not cause separate airflow disturbance around the air outlet 6 and will not form a vortex.

[0054] The radial inner side of the dynamic balance adjustment plate on the front and rear discs is provided with an arc surface 502. When the gas in the gap between the front and rear discs and the return guide plate 11 is discharged from the inside to the outside, the arc-shaped guidance of the arc surface 502 can reduce the impact of the gas on the dynamic balance adjustment plate 5, thereby reducing the operating noise, and further reducing the amplitude of impeller vibration.

[0055] In one specific embodiment, airflow guiding arc surfaces 503 are respectively provided on both sides of the circumferential direction of the dynamic balance adjustment plates on the front and rear discs. The radius of the airflow guiding arc surface 503 is 59mm±2mm. This radius of the airflow guiding arc surface 503 plays a significant role in guiding and relieving the airflow entering the gap between the front and rear discs and the side return guide plates 11. The arc design of the airflow guiding arc surface 503 has a synergistic effect with the gas flow direction when the impeller rotates, such as... Figure 2 As shown, since the impeller rotates counterclockwise, the airflow direction in the gap between the front and rear discs and the return guide plates 11 on both sides is also counterclockwise. Under the action of centrifugal force, when the airflow in the gap touches the airflow guide arc surface 503, under the action of the 59mm radius arc, the airflow is further guided in the counterclockwise direction. Currently, in the design of impellers, in order to increase the stability of gas transmission and reduce noise, the blades in the impeller are usually designed as arc structures. Therefore, the airflow guide arc surface 503 on the dynamic balance adjustment plate 5 and the arc structure blades work together. In this way, the airflow will not directly interfere with the gas normally discharged from the outlet 6, but will instead merge with the normal airflow, ensuring the normal transmission of gas. The gas discharged from the outlet 6 will not be interfered with by other gases, further reducing the operating noise of the fan and preventing additional impact on the impeller and adjacent components.

[0056] In one specific embodiment, multiple dynamic balance adjustment plates 5 are fixed to the front plate 1 and the rear plate 2 by welding, respectively. Different specifications of dynamic balance adjustment plates 5 can be selected for welding and assembly according to actual needs, which has a wide range of applications and great flexibility.

[0057] The method for dynamically balancing the impeller of the centrifugal blower equipped with a dynamic balancing device includes the following steps:

[0058] Step (1): Prepare the impeller and select multiple dynamic balancing plates of appropriate size 5 according to the outer diameter of the impeller;

[0059] Step (2): Weld and fix multiple dynamic balance adjustment plates 5 to the outermost radial position of the outer end face of the front plate 1 and the rear plate 2 respectively, and the multiple dynamic balance adjustment plates 5 are evenly distributed along the circumferential direction on the front plate 1 and the rear plate 2 respectively.

[0060] Step (3): Install the impeller with the welded dynamic balancing adjustment plate 5 onto the balancing machine for dynamic balancing test;

[0061] Step (4): According to the phase angle indicated by the balancing device, find the dynamic balancing adjustment plate 5 that needs to be de-weighted on the front plate 1 and rear plate 2 of the impeller respectively, and grind the dynamic balancing adjustment plate 5 that needs to be de-weighted to remove the weight.

[0062] Step (5): After grinding and removing weight, perform dynamic balancing retest on the impeller and determine whether the required balance accuracy is achieved based on the new measurement results;

[0063] Step (6): When the imbalance is less than the set tolerance range, the dynamic balancing adjustment is completed, and the impeller can be installed and used normally at this time;

[0064] Step (7): When the imbalance is greater than the set tolerance range, it is necessary to repeat steps (3)-(5) until the imbalance is less than the set tolerance range, and finally complete the dynamic balance adjustment.

[0065] In step (4), during the process of grinding and removing weight from the dynamic balance adjustment plate 5, it should be ensured that the thickness of the inner side of the dynamic balance adjustment plate 5 after grinding is not greater than the thickness of the outer side. This is to minimize the amount of gas entering the gap between the front and rear discs and the return guide plate 11, and to ensure the smooth discharge of the gas in the gap.

[0066] However, the above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any substitution of equivalent components or equivalent changes and modifications made in accordance with the scope of protection of the present invention should still fall within the scope of the claims of the present invention.

Claims

1. A method for dynamic balancing of an impeller for a centrifugal blower, wherein the impeller used in the dynamic balancing method has a front disc and a rear disc, a through hole is provided at the middle position of the front disc and the rear disc respectively, and a plurality of blades are fixedly provided between the front disc and the rear disc, the plurality of blades being arranged circumferentially between the front disc and the rear disc, characterized in that: Includes the following steps: Step (1): Prepare the impeller and select multiple dynamic balancing plates of appropriate size according to the outer diameter of the impeller; Step (2): Weld and fix multiple dynamic balance adjustment plates to the outermost radial position of the outer end face of the front plate and the rear plate respectively, and the multiple dynamic balance adjustment plates are evenly distributed along the circumferential direction on the front plate and the rear plate respectively. Step (3): Install the impeller with the welded dynamic balancing adjustment plate onto the balancing machine for dynamic balancing test; Step (4): According to the phase angle indicated by the balancing equipment, find the dynamic balancing adjustment plates that need to be de-weighted on the front and rear discs of the impeller respectively, and grind the dynamic balancing adjustment plates that need to be de-weighted to remove the weight. Step (5): After grinding and removing weight, perform dynamic balancing retest on the impeller and determine whether the required balance accuracy is achieved based on the new measurement results; Step (6): When the imbalance is less than the set tolerance range, the dynamic balancing adjustment is completed, and the impeller can be installed and used normally at this time; Step (7): When the imbalance is greater than the set tolerance range, it is necessary to repeat steps (3)-(5) until the imbalance is less than the set tolerance range, and finally complete the dynamic balance adjustment. The dynamic balance adjustment plates on the front and rear discs are blade-shaped; the radial outer side of the dynamic balance adjustment plates on the front and rear discs is chamfered; the radial inner side of the dynamic balance adjustment plates on the front and rear discs is arc-shaped. The front and rear discs have airflow guiding arc surfaces on both sides of their circumference, and the radius of the airflow guiding arc surfaces is 59mm±2mm. The thickness of the dynamic balance adjustment plates on the front and rear discs is 8mm ± 1mm. The radial width of the dynamic balance adjustment plates on the front and rear discs is 110mm ± 5mm; The ratio between the radial width of the dynamic balancing plate and the corresponding radii of the front and rear discs is 1:

10.

2. The method for dynamic balancing of the impeller for a centrifugal blower according to claim 1, characterized in that: In step (4), during the process of grinding and removing weight from the dynamic balance adjustment plate, it should be ensured that the thickness of the inner side of the dynamic balance adjustment plate after grinding is not greater than the thickness of its outer side, so as to reduce the amount of gas entering the gap between the front and rear discs and the return guide plate, and to ensure the smooth discharge of gas in the gap.

3. The method for dynamic balancing of the impeller for a centrifugal blower according to claim 2, characterized in that: An air inlet sealing ring is fixedly provided on the inner circumference of the through hole in the middle of the front disc, and a shaft disc is fixedly provided on the inner circumference of the through hole in the middle of the rear disc, with an axial through hole in the middle of the shaft disc. Multiple airflow channels are formed between the front disc, the rear disc, and the axle disc, and air inlets and outlets are respectively provided on the radial inner and outer sides of the airflow channels; Multiple dynamic balance adjustment plates are provided at the outer circumference of the outer end of the front disc, and the multiple dynamic balance adjustment plates are evenly distributed along the circumferential direction of the front disc. Multiple dynamic balance adjustment plates are provided on the outer circumference of the outer end of the rear disc, and the multiple dynamic balance adjustment plates are evenly distributed along the circumferential direction of the rear disc.

4. The method for dynamic balancing of the impeller for a centrifugal blower according to claim 3, characterized in that: The multiple dynamic balance adjustment plates are respectively fixed to the front plate and the rear plate by welding.

5. The method for dynamic balancing of the impeller for a centrifugal blower according to claim 4, characterized in that: The number of dynamic balance adjustment plates on both the front and rear plates is twelve.

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