Dynamic balance adjusting method of impeller for centrifugal blower

Abstract

According to the dynamic balance adjusting method of the impeller for the centrifugal blower, the impeller used in the method 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 side end of the front disc, and the dynamic balance adjusting pieces are evenly distributed in the circumferential direction of the front disc; a plurality of dynamic balance adjusting pieces are arranged at the outer circumferential position of the outer side end of the rear disc and evenly distributed in the circumferential direction of the rear disc. The multiple dynamic balance adjusting pieces are arranged on the outer circumferential end faces of the front disc and the rear disc of the impeller respectively, in the dynamic balance debugging process of the impeller, only the dynamic balance adjusting pieces at the designated positions need to be polished for weight removal, polishing damage to the front disc and the rear disc is not needed, and the structural strength of the front disc or the rear disc cannot be damaged. The invention can be widely applied to centrifugal blowers.

Description

Technical Field

[0001] The present invention relates to an impeller, in particular to a dynamic balance adjustment method for an impeller used in a centrifugal blower. Background Art

[0002] The impellers in centrifugal blowers need to be dynamically balanced before assembly to eliminate or minimize the centrifugal force imbalance caused by uneven impeller mass distribution, thereby ensuring that the blower can operate smoothly, efficiently, safely and for a long time.

[0003] At present, most impeller dynamic balancing methods use the deweighting method, that is, the specified end face position of the outer circumference of the front or rear disc of the impeller is ground and deweighted, thereby offsetting the centrifugal force imbalance problem generated at this position during rotation, and finally achieving the coincidence of the synthetic center of mass of the impeller with the axis of rotation, thereby achieving smooth operation.

[0004] However, this deweighting method directly destroys the structural strength of the front disc or the rear disc, reduces the service life of the front disc or the rear disc, and after grinding, the thickness of the outer circumference of the front disc or the rear disc becomes significantly thinner. When the impeller rotates, the outer circumference of the impeller will vibrate to varying degrees, resulting in varying degrees of vortexes at the impeller outlet, which increases the operating noise of the blower.

[0005] At the same time, part of the gas will enter the gap between the impeller and the return flow guide plates on both sides through the impeller outlet. 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 stability of the impeller operation. Summary of the Invention

[0006] In response to the above technical problems, the present invention provides a dynamic balancing adjustment method for an impeller for a centrifugal blower, wherein a plurality of dynamic balancing adjustment plates are respectively provided on the outer circumferential end faces of the front disk and the rear disk of the impeller. During the dynamic balancing debugging process of the impeller, it is only necessary to grind and remove the weight of the dynamic balancing adjustment plates at the specified positions, without causing grinding damage to the front disk and the rear disk, without damaging the structural strength of the front disk or the rear disk itself, and avoiding the problem of impeller rotation jitter; moreover, when the impeller rotates, under the action of the centrifugal force of the dynamic balancing adjustment plates, the gas entering the gap between the impeller and the return flow guide plates on both sides will be quickly discharged, and will not cause axial impact on the impeller.

[0007] To this end, the technical solution of the present invention is a method for adjusting the dynamic balance of an impeller for a centrifugal blower, comprising the following steps: Step (1): Prepare the impeller and select a number of dynamic balancing plates of appropriate sizes according to the outer diameter of the impeller; Step (2): Welding and fixing a plurality of dynamic balancing adjustment plates to the outermost radial positions of the outer end surfaces of the front disc and the rear disc, respectively, and the plurality of dynamic balancing adjustment plates are evenly distributed along the circumferential direction on the front disc and the rear disc, respectively; Step (3): Install the impeller with the dynamic balance adjustment plate welded on the balancing machine for dynamic balance detection; Step (4): According to the phase angle indicated by the balancing equipment, find the dynamic balancing adjustment pieces that need to be deweighted on the front and rear discs of the impeller, and grind and deweight the dynamic balancing adjustment pieces that need to be deweighted; Step (5): After grinding and removing weight, re-measure the dynamic balance of the impeller and determine whether the required balance accuracy is achieved based on the new measurement results; Step (6): When the unbalance amount is less than the set tolerance range, the dynamic balance adjustment is completed and the impeller can be installed and used normally; Step (7): When the unbalance amount is greater than the set tolerance range, repeat steps (3) to (5) until the unbalance amount is less than the set tolerance range, and finally complete the dynamic balance adjustment.

[0008] Preferably, in step (4), during the grinding and deweighting process of the dynamic balancing adjustment plate, it should be ensured that the thickness of the inner side of the dynamic balancing adjustment plate after grinding is not greater than the thickness of the outer side, so that the amount of gas entering the gap between the front and rear disks and the return guide plate can be significantly reduced, and the gas in the gap can be smoothly discharged.

[0009] Preferably, the impeller used in the above-mentioned dynamic balancing adjustment method comprises a front disc and a rear disc, wherein a through hole is respectively provided in the middle position of the front disc and the rear disc, and a plurality of blades are fixedly provided between the front disc and the rear disc, and the plurality of blades are arranged along the circumferential direction between the front disc and the rear disc; An air inlet sealing ring is fixedly provided on the inner circumference of the through hole in the middle of the front disc, and an axle disc is fixedly provided on the inner circumference of the through hole in the middle of the rear disc, and an axially penetrating hole is provided in the middle of the axle disc; Multiple airflow channels are formed between the front disc, the rear disc and the shaft disc, and air inlets and outlets are provided on the radial inner and outer sides of the airflow channels respectively; A plurality of dynamic balancing adjustment plates are provided at the outer circumferential position of the outer end of the front disc, and the plurality of dynamic balancing adjustment plates are evenly distributed along the circumferential direction of the front disc; A plurality of dynamic balancing adjustment plates are provided at the outer circumferential position of the outer end portion of the rear disc, and the plurality of dynamic balancing adjustment plates are evenly distributed along the circumferential direction of the rear disc.

[0010] Preferably, the dynamic balance adjustment pieces on the front disc and the rear disc are shaped like blades.

[0011] Preferably, the thickness of the dynamic balance adjustment plates on the front disc and the rear disc is 8 mm ± 1 mm.

[0012] Preferably, the radial width of the dynamic balancing adjustment plates on the front disc and the rear disc is 110 mm ± 5 mm.

[0013] Preferably, the ratio between the radial width of the dynamic balancing adjustment plate and the radius of the corresponding front disc and rear disc is 1:10 respectively.

[0014] Preferably, the number of dynamic balance adjustment plates on the front disc and the rear disc is twelve.

[0015] Preferably, radially outer portions of the dynamic balancing adjustment plates on the front and rear discs are chamfered; The radial inner sides of the dynamic balance adjustment plates on the front disc and the rear disc are provided with arc surfaces.

[0016] Preferably, airflow guiding arc surfaces 503 are respectively provided on both sides of the circumferential direction of the dynamic balancing adjustment plates on the front disc and the rear disc, and the radius of the airflow guiding arc surfaces is 59 mm ± 2 mm.

[0017] Preferably, the plurality of dynamic balancing adjustment plates are fixed to the front disc and the rear disc respectively by welding.

[0018] The beneficial effect of the present invention is that, by providing a plurality of dynamic balancing adjustment pieces at the outer circumferential position of the outer end portion of the front disc, the plurality of dynamic balancing adjustment pieces are evenly distributed along the circumferential direction of the front disc, and by providing a plurality of dynamic balancing adjustment pieces at the outer circumferential position of the outer end portion of the rear disc, the plurality of dynamic balancing adjustment pieces are evenly distributed along the circumferential direction of the rear disc, during the dynamic balancing commissioning of the impeller, it is only necessary to grind and remove weight from the dynamic balancing adjustment pieces at the designated positions, without causing grinding damage to the front disc and the rear disc, without damaging the self-structural strength of the front disc or the rear disc, and thus avoiding the problem of impeller rotation jitter; Moreover, after the impeller is assembled, the thickness of the balancing plate can reduce the gap between the front and rear discs and the return flow guide plates on both sides, thereby reducing the amount of gas entering the gap when the impeller rotates, and avoiding excessive gas pressure in the gap, which may cause axial impact on the impeller and affect the impeller's rotation stability. At the same time, when a small amount of gas enters the gap, it will be quickly discharged outward along the gap between the two adjacent balance adjustment plates under the action of the centrifugal force of the impeller rotation. If there is no balance adjustment plate on the outside of the front and rear disks, the airflow will be more dispersed when discharged, forming an irregular airflow, which will also cause irregular impact on the impeller and the return flow guide plate. Moreover, the irregular airflow direction will affect the flow of normal gas discharged from the outlet, causing interference, and ultimately affecting the transmission guidance of the overall airflow. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a cross-sectional view of the structure of the present invention; Figure 2 This invention Figure 1Schematic diagram of the A-axis structure and impeller rotation direction; Figure 3 This is a structural principle diagram of the present invention applied to a centrifugal blower; Figure 4 This invention Figure 1 Enlarged view of point B in the middle; Figure 5 This invention Figure 3 Schematic diagram of the C-direction structure; Figure 6 This invention Figure 5 Enlarged view of point D in the middle; Figure 7 This invention Figure 2 Enlarged view of point E in the middle.

[0020] Explanation of symbols in the figure: 1. Front disc; 2. Rear disc; 3. Air inlet sealing ring; 4. Shaft disc; 5. Dynamic balancing adjustment plate; 501. Chamfer; 502. Arc surface; 503. Airflow guide arc surface; 6. Air outlet; 7. Blades; 8. Airflow channel; 9. Air inlet; 10. Inlet volute; 11. Return flow guide plate. DETAILED DESCRIPTION

[0021] The present invention will be further described below with reference to the embodiments.

[0022] pass Figure 1-Figure 7 It can be seen that the impeller for the centrifugal blower with a dynamic balancing adjustment device is provided with a front disc 1 and a rear disc 2, and through holes are provided in the middle positions of the front disc 1 and the rear disc 2 respectively. A plurality of blades 7 are fixed between the front disc 1 and the rear disc 2, and the plurality of blades 7 are arranged along the circumferential direction between the front disc 1 and the rear disc 2.

[0023] An air inlet sealing ring 3 is fixedly provided on the inner circumference of the through hole in the middle of the front disk 1, and a shaft disk 4 is fixed on the inner circumference of the through hole in the middle of the rear disk 2. An axially penetrating hole is provided in the middle position of the shaft disk 4. Multiple air flow channels 8 are formed between the front disk 1, the rear disk 2 and the shaft disk 4. An air inlet 9 and an air outlet 6 are respectively provided on the radial inner and outer sides of the air flow channel 8. When the fan is running, the gas enters from the air inlet 9, and under the action of centrifugal force, flows along the air flow channel 8 to the outer circumference, and is finally discharged from the air outlet 6 to enter the next air flow channel to realize gas transmission.

[0024] A plurality of dynamic balancing adjustment pieces 5 are provided at the outer circumferential position of the outer end of the front disc 1, and the plurality of dynamic balancing adjustment pieces 5 are evenly distributed along the circumferential direction of the front disc 1. A plurality of dynamic balancing adjustment pieces 5 are provided at the outer circumferential position of the outer end of the rear disc 2, and the plurality of dynamic balancing adjustment pieces 5 are evenly distributed along the circumferential direction of the rear disc 2. In this way, during the dynamic balancing commissioning of the impeller, it is only necessary to grind and remove the weight of the dynamic balancing adjustment pieces 5 at the designated positions, without causing grinding damage to the front and rear discs, and without damaging the structural strength of the front or rear discs, thereby avoiding the problem of impeller rotation jitter. Moreover, after the impeller is assembled, the thickness of the balancing adjustment sheet 5 can reduce the gap between the front and rear disks and the return flow guide plates 11 on both sides, thereby reducing the amount of gas entering the gap when the impeller rotates, thereby avoiding excessive gas pressure in the gap, causing axial impact on the impeller, and affecting the rotation stability of the impeller.

[0025] The most important thing is that when a small amount of gas enters the gap, it will be quickly discharged outward along the gap between the two adjacent balance adjustment plates 5 under the action of the centrifugal force of the impeller rotation. If there is no balance adjustment plate 5 on the outside of the front and rear disks, the airflow will be more dispersed when discharged, forming an irregular airflow, which will also cause irregular impact on the impeller and the return flow guide plate 11. Moreover, the irregular airflow direction will affect the flow of normal gas discharged from the air outlet 6, causing interference, and ultimately affecting the transmission guidance of the overall airflow.

[0026] In a specific embodiment, the dynamic balance adjustment piece 5 on the front disc 1 and the rear disc 2 is in the shape of a blade, and Figure 2 It can be seen that the arrangement direction of the blade-shaped dynamic balancing adjustment piece 5 is in the forward direction of the impeller's rotation direction, which can reduce the resistance of the impeller during rotation and play an auxiliary role in guiding the airflow.

[0027] In a specific embodiment, the thickness of the dynamic balancing adjustment plate 5 on the front disk 1 and the rear disk 2 is 8mm±1mm, which is a reasonable thickness 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, and the impeller will inevitably shake slightly when rotating for a long time. If the gap is too small, the dynamic balancing adjustment plate 5 and the return guide plate 11 will have contact friction, causing damage to the impeller and the return guide plate 11. In addition, if the gap is too small, the operating noise will increase. If the thickness is too thin, it cannot meet the thickness requirement for grinding and deweighting during dynamic balancing. At the same time, if the thickness is too thin, the function of concentrated and directional discharge of gas in the gap between the front and rear disks and the return guide plate 11 is lost. The airflow will also be more dispersed when discharged, forming irregular airflow, causing irregular impact on the impeller and the return guide plate 11.

[0028] In a specific embodiment, the radial width of the dynamic balancing adjustment plate 5 on the front disc 1 and the rear disc 2 is 110 mm ± 5 mm, which is the size required by a commonly used centrifugal blower and can also be customized according to actual needs.

[0029] The ratio between the radial width of the dynamic balancing adjustment sheet 5 and the radius of the corresponding front disc 1 and rear disc 2 is 1:10 respectively. This ratio has strict standards. 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 dynamic balancing adjustment sheet 5 separately on the inner side of a dynamic balancing adjustment sheet 5 and then grind it. The operation is complicated and tedious, and the purpose of the design of this patent is lost. If the ratio is too small, the impeller rotation load will be increased, the resistance will be increased, especially when the impeller starts and stops, which is most obvious, thereby reducing the service life of the impeller.

[0030] In a specific embodiment, the number of dynamic balance adjustment plates 5 on the front disc 1 and the rear disc 2 are both twelve, which can fully meet the deweighting angle requirements during dynamic balancing grinding of most impellers.

[0031] In a specific embodiment, a chamfer 501 is provided at the radial outer position of the dynamic balancing adjustment plate 5 on the front disk 1 and the rear disk 2. When the dynamic balancing adjustment plate 5 guides and discharges the gas in the gap between the front and rear disks and the return guide plate 11, 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, which will not cause separate airflow disturbances around the air outlet 6 and will not form vortices.

[0032] A circular arc surface 502 is provided on the radial inner side of the dynamic balance adjustment plate on the front disk and the rear disk. When the gas in the gap between the front and rear disks and the return flow guide plate 11 is discharged from the inside to the outside, the arc-shaped guiding action of the circular 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 the impeller vibration.

[0033] In a specific embodiment, airflow guide arc surfaces 503 are respectively provided on both sides of the circumferential direction of the dynamic balance adjustment plate on the front disk and the rear disk. The radius of the airflow guide arc surface 503 is 59 mm ± 2 mm. The airflow guide arc surface 503 of this radius size plays a significant role in draining and relieving the airflow entering the gap between the front and rear disks and the return flow guide plates 11 on both sides. The curvature design of the airflow guide arc surface 503 has a synergistic effect with the gas flow direction during the rotation of the impeller, such as Figure 2As shown, since the impeller rotates counterclockwise, the direction of the airflow in the gap between the front and rear disks and the return flow 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, the airflow is further guided in the counterclockwise direction under the action of the arc with a radius of 59mm. At present, in the design of the impeller, in order to increase the stability of gas transmission and reduce noise, the blades in the impeller are usually designed as an arc structure. Therefore, the airflow guide arc surface 503 on the dynamic balance adjustment plate 5 forms a synergistic effect with the blades of the arc structure. In this way, the airflow will not directly interfere with the normal discharge of the gas from the air outlet 6, but will merge with the normal airflow, ensuring the normal transmission of the gas. The gas discharged from the air outlet 6 will not be interfered with by other gases, further reducing the operating noise of the fan, and will not cause additional impact on the impeller and adjacent components.

[0034] In a specific embodiment, a plurality of dynamic balancing adjustment plates 5 are respectively fixed to the front disc 1 and the rear disc 2 by welding. Dynamic balancing adjustment plates 5 of different specifications can be selected for welding and assembly according to actual needs, which has a wide range of applications and great flexibility.

[0035] The dynamic balance adjustment method for the impeller of a centrifugal blower with a dynamic balance adjustment device comprises the following steps: Step (1): Prepare the impeller and select a plurality of dynamic balancing adjustment plates 5 of appropriate sizes according to the outer diameter of the impeller; Step (2): Welding and fixing a plurality of dynamic balancing adjustment plates 5 to the outermost radial positions of the outer end surfaces of the front disc 1 and the rear disc 2, respectively, and the plurality of dynamic balancing adjustment plates 5 are evenly distributed along the circumferential direction on the front disc 1 and the rear disc 2; Step (3): Install the impeller with the dynamic balance adjustment piece 5 welded on it on a balancing machine for dynamic balance testing; Step (4): According to the phase angle indicated by the balancing device, find the dynamic balancing adjustment pieces 5 that need to be deweighted on the front disc 1 and the rear disc 2 of the impeller, and grind and deweight the dynamic balancing adjustment pieces 5 that need to be deweighted; Step (5): After grinding and removing weight, re-measure the dynamic balance of the impeller and determine whether the required balance accuracy is achieved based on the new measurement results; Step (6): When the unbalance amount is less than the set tolerance range, the dynamic balance adjustment is completed and the impeller can be installed and used normally; Step (7): When the unbalance amount is greater than the set tolerance range, repeat steps (3) to (5) until the unbalance amount is less than the set tolerance range, and finally complete the dynamic balance adjustment.

[0036] Among them, in step (4), during the process of grinding and removing the weight of the dynamic balancing adjustment plate 5, it should be ensured that the thickness of the inner side of the dynamic balancing adjustment plate 5 after grinding is not greater than the thickness of the outer side, so as to minimize the amount of gas entering the gap between the front and rear disks and the return flow guide plate 11 and ensure the smooth discharge of the gas in the gap.

[0037] However, the above description is merely a specific embodiment of the present invention and should not be used to limit the scope of implementation of the present invention. Therefore, the replacement of equivalent components, or equivalent changes and modifications made according to the scope of protection of the present invention should still fall within the scope covered by the claims of the present invention.

Claims

1. A method for adjusting the dynamic balance of an impeller for a centrifugal blower, characterized by: The steps include: Step (1): Prepare the impeller and select a number of dynamic balancing plates of appropriate sizes according to the outer diameter of the impeller; Step (2): Welding and fixing a plurality of dynamic balancing adjustment plates to the outermost radial positions of the outer end surfaces of the front disc and the rear disc, respectively, and the plurality of dynamic balancing adjustment plates are evenly distributed along the circumferential direction on the front disc and the rear disc, respectively; Step (3): Install the impeller with the dynamic balance adjustment plate welded on the balancing machine for dynamic balance detection; Step (4): According to the phase angle indicated by the balancing equipment, find the dynamic balancing adjustment pieces that need to be deweighted on the front and rear discs of the impeller, and grind and deweight the dynamic balancing adjustment pieces that need to be deweighted; Step (5): After grinding and removing weight, re-measure the dynamic balance of the impeller and determine whether the required balance accuracy is achieved based on the new measurement results; Step (6): When the unbalance amount is less than the set tolerance range, the dynamic balancing adjustment is completed and the impeller can be installed and used normally; Step (7): When the unbalance amount is greater than the set tolerance range, repeat steps (3) to (5) until the unbalance amount is less than the set tolerance range, and finally complete the dynamic balance adjustment.

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

3. The method for adjusting the dynamic balance of a centrifugal blower impeller according to claim 2, wherein: The impeller used in the dynamic balancing method comprises a front disc and a rear disc, wherein a through hole is respectively provided in the middle of the front disc and the rear disc, and a plurality of blades are fixedly provided between the front disc and the rear disc, wherein the plurality of blades are arranged along the circumferential direction between the front disc and the rear disc; An air inlet sealing ring is fixedly provided on the inner circumference of the through hole in the middle of the front disc, and an axle disc is fixedly provided on the inner circumference of the through hole in the middle of the rear disc, and an axially penetrating hole is provided in the middle of the axle disc; A plurality of air flow channels are formed between the front disc, the rear disc and the shaft disc, and an air inlet and an air outlet are respectively provided on the radial inner side and the radial outer side of the air flow channel; A plurality of dynamic balancing adjustment plates are provided at the outer circumferential position of the outer end portion of the front disc, and the plurality of dynamic balancing adjustment plates are evenly distributed along the circumferential direction of the front disc; A plurality of dynamic balance adjustment plates are provided at the outer circumferential position of the outer end portion of the rear disc, and the plurality of dynamic balance adjustment plates are evenly distributed along the circumferential direction of the rear disc.

4. The method for adjusting the dynamic balance of a centrifugal blower impeller according to claim 3, wherein: The dynamic balance adjustment pieces on the front disc and the rear disc are in the shape of blades.

5. The method for dynamic balancing of an impeller for a centrifugal blower according to claim 4, wherein: The radial outer sides of the dynamic balance adjustment plates on the front disc and the rear disc are chamfered; The radial inner sides of the dynamic balance adjustment plates on the front disc and the rear disc are provided with arc surfaces; Airflow guiding arc surfaces are respectively provided on both sides of the circumferential direction of the dynamic balance adjustment plates on the front disc and the rear disc, and the radius of the airflow guiding arc surfaces is 59 mm ± 2 mm.

6. The method for dynamic balancing of an impeller for a centrifugal blower according to claim 5, wherein: The plurality of dynamic balancing adjustment plates are respectively fixed to the front disc and the rear disc by welding.

7. The method for adjusting the dynamic balance of an impeller for a centrifugal blower according to claim 6, wherein: The thickness of the dynamic balance adjustment plates on the front disc and the rear disc is 8mm±1mm.

8. The method for dynamic balancing of an impeller for a centrifugal blower according to claim 6, wherein: The radial width of the dynamic balance adjustment plates on the front disc and the rear disc is 110 mm ± 5 mm.

9. The method for dynamic balancing of an impeller for a centrifugal blower according to claim 8, wherein: The ratio between the radial width of the dynamic balancing adjustment plate and the radius of the corresponding front disc and rear disc is 1:

10.

10. The method for adjusting the dynamic balance of a centrifugal blower impeller according to any one of claims 3 to 9, characterized in that: There are twelve dynamic balance adjustment plates on both the front disc and the rear disc.

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