Single-plate impeller structure of centrifugal fan

Abstract

The utility model relates to the technical field of fluid machinery, in particular to an improved scheme of an impeller structure of a centrifugal fan. The utility model discloses a novel impeller structure of a centrifugal fan, which effectively solves the technical problems of welding slag residue, dynamic balance imbalance and the like on the premise of ensuring aerodynamic efficiency by improving a traditional wing type hollow blade into a single plate type solid structure and matching with the optimized configuration of a 46-degree outlet angle and 12 blades. Through actual measurement, the vibration value of the improved impeller is reduced to 2.5 mm / s, and the manufacturing qualification rate is increased to 100%.

Description

TECHNICAL FIELD

[0001] The utility model relates to fluid machinery technical field, concretely relates to a centrifugal fan impeller structure improvement scheme, especially suitable for centrifugal fan impeller optimization design of industrial dust removal, ventilation system. BACKGROUND

[0002] The traditional centrifugal fan impeller adopts the wing type blade structure (such as the wing type blade structure shown in the accompanying drawings), which has the following technical defects: Figure 1 (a) shown), it has the following technical defects:

[0003] 1. Its manufacturing process is complex: hollow structure is formed by welding two arc-shaped steel plates and reinforcing rib plates, and the welding procedure is as many as 15, the wing type blade is composed of the upper blade, the lower blade, the reinforcing rib plate (one) and the reinforcing rib plate (two). Figure 1 (b) shown: the upper blade and the lower blade are pressed into the wing blade aerodynamic profile under the action of the press by using a special mold, then the rib plate (one) and the rib plate (two) are welded on the upper blade, and then the lower blade is combined, and the lower blade plug welding hole is shown in (b), the lower blade and the rib plate (one) and the rib plate (two) are assembled and welded, and after welding, the upper blade and the lower blade are assembled and welded at the head and tail of the blade, so that the welding of the wing type blade is completed. Figure 1 (c) shown, the wing type blade impeller is fixed on the riveting platform of the impeller after the flatness of the rear disc reaches the riveting technical requirements of the fan, the welding profile of the blade is drawn on the rear disc by using the scribing tool and the positioning tool according to the drawing and the process requirements, the assembled and welded blade is riveted on the rear disc as shown in (c), then the front disc is covered, the gap between the front disc and the blade is observed, the model of the blade and the front disc is adjusted according to the drawing and the process requirements, the surface is polished after adjustment, the front disc is assembled and welded with the blade again, and the riveting of the wing type blade is completed.

[0004] 2. The assembly welding structure of the wing type blade impeller is complex: as shown in (c), the wing type blade impeller is fixed on the riveting platform of the impeller after the flatness of the rear disc reaches the riveting technical requirements of the fan, the welding profile of the blade is drawn on the rear disc by using the scribing tool and the positioning tool according to the drawing and the process requirements, the assembled and welded blade is riveted on the rear disc as shown in (c), then the front disc is covered, the gap between the front disc and the blade is observed, the model of the blade and the front disc is adjusted according to the drawing and the process requirements, the surface is polished after adjustment, the front disc is assembled and welded with the blade again, and the riveting of the wing type blade is completed. Figure 1 Figure 1 3. There is pollution residue inside: 30-40% of the welding slag is easy to stay in the cavity of the blade during the assembly welding process of the wing type blade, which is not easy to remove, and the molten steel also flows into the cavity of the blade during the assembly welding process of the front disc and the blade, which cannot be removed, and the impeller is put into the annealing furnace for whole annealing when the assembly welding of the impeller is completed. Figure 1

[0005] 3. There is pollution residue inside: 30-40% of the welding slag is easy to stay in the cavity of the blade during the assembly welding process of the wing type blade, which is not easy to remove, and the molten steel also flows into the cavity of the blade during the assembly welding process of the front disc and the blade, which cannot be removed, and the impeller is put into the annealing furnace for whole annealing when the assembly welding of the impeller is completed.

[0006] ​​4. Easy to destroy the dynamic balance destruction: in the process of wing type blade group welding and the process of impeller welding, heat treatment, the residue produced causes uneven mass distribution of the impeller, which seriously destroys the dynamic balance of the impeller during rotation, and the actual measured dynamic balance deviation is far more than the minimum standard requirement of ISO1940 G6.3 level, which causes vibration during rotation of the rotor.

[0007] 5. Large aerodynamic noise: the cavity structure generates 5-8dB(A) of additional aerodynamic noise when rotating at high speed (>1500rpm). SUMMARY

[0008] The utility model hopes to provide a centrifugal fan single board type impeller structure, specific scheme as follows:

[0009] A centrifugal fan single board type impeller structure, comprising an arc front disc and a rear disc, a single board type blade is arranged between the arc front disc and the rear disc, and a hub disc bolt hole is arranged on the rear disc.

[0010] The outlet angle of the single board type blade is 46±1°.

[0011] The single board type blade is 12 pieces, and is distributed at equal angular velocity.

[0012] The arc front disc is a front disc of involute type arc structure.

[0013] The rear disc is detachably provided with a perpendicularity welding positioning block, and the perpendicularity welding positioning block is arranged in cooperation with the single board type blade.

[0014] The perpendicularity welding positioning block is spot welded on the rear disc. The perpendicularity welding positioning block is spot welded to ensure the perpendicularity of the blade after riveting, and under the action of the positioning block, the blade is prevented from deforming due to welding stress after welding with the rear disc and the front disc, so that the perpendicularity welding positioning block is only used in product production and is not part of the product.

[0015] The utility model discloses a novel centrifugal fan impeller structure, which improves the traditional hollow blade of the wing type into a single board type solid structure, cooperates with the optimized configuration of the 46° outlet angle and 12 blades, effectively solves the technical problems of welding slag residue and dynamic balance disorder under the premise of ensuring the aerodynamic efficiency. According to actual measurement, the vibration value of the improved impeller is reduced to 2.5mm / s (60% lower than the original type), and the manufacturing qualified rate is improved to 100%. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is prior art figure;

[0017] Figure 2 It is a structure schematic view of the utility model discloses a novel centrifugal fan impeller structure;

[0018] Figure 3 It is a structure diagram of a single plate type blade in a novel centrifugal fan impeller structure of the utility model.

[0019] Figure 4 It is a structure diagram of a single plate type blade in a novel centrifugal fan impeller structure of the utility model. Figure 1 ;

[0020] Figure 5 It is a structure diagram of an arc-shaped front disc in a novel centrifugal fan impeller structure of the utility model.

[0021] Figure 6 It is a structure diagram of an arc-shaped front disc in a novel centrifugal fan impeller structure of the utility model. Figure 2 ;

[0022] In which the reference numerals: 1. arc-shaped front disc; 2. rear disc; 3. single plate type blade; 4. hub disc bolt hole; 5. perpendicularity welding positioning block. DETAILED DESCRIPTION

[0023] The utility model discloses a novel centrifugal fan impeller structure, which is characterized by the following technical scheme. Figures 2-6 The utility model discloses a novel centrifugal fan impeller structure, which is characterized by the following technical scheme.

[0024] A single plate type blade 3 is arranged between the arc-shaped front disc 1 and the rear disc 2. Figure 4 The outlet angle of the single plate type blade 3 is 46±1° (see FIG. 2). The single plate type blade 3 is 12 pieces and is distributed at an equal angular velocity (interval angle 25.7°). The arc-shaped front disc 1 is a front disc with a involute arc-shaped structure.

[0025] The perpendicularity welding positioning block 5 is detachably arranged on the rear disc 2 and is arranged in cooperation with the single plate type blade 3.

[0026] The perpendicularity welding positioning block 5 is spot-welded on the rear disc 2. The perpendicularity welding positioning block 5 is spot-welded to ensure the perpendicularity of the single plate type blade 3 after riveting and to prevent the single plate type blade 3 from deforming due to welding stress after being welded with the rear disc 2 and the arc-shaped front disc 1.

[0027] The single plate type blade 3 is formed by one-time laser blanking of a steel plate, and the burrs are polished after blanking, and then the blade is leveled by a press. According to the profile of the single plate type blade 3 on the rear disc 2, the single plate type blade 3 is riveted and welded on the rear disc 2.

[0028] This invention replaces the original airfoil blade with a single-plate blade 3 to improve the rationality of the processing technology, reduce impeller rotation noise, and solve the impeller dynamic balance problem. The new single-plate blade 3 does not require complex forming processes because it is a straight plate without curvature and is a single plate, eliminating the need for welding. After laser cutting, the blade is leveled by a press and then welded to the back plate, without complex welding processes. The single-plate blade 3 also eliminates the problem of weld slag and oxide scale disrupting dynamic balance.

[0029] This utility model discloses a novel centrifugal fan impeller structure. By improving the traditional airfoil-shaped hollow blades into a single-plate solid structure, and with an optimized configuration of a 46° outlet angle and 12 single-plate blades 3, it effectively solves technical problems such as weld slag residue and dynamic imbalance while ensuring aerodynamic efficiency. Actual measurements show that the vibration value of the improved impeller structure is reduced to 2.5 mm / s (60% lower than the prototype), and the manufacturing qualification rate is increased to 100%.

[0030] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A centrifugal fan single plate impeller structure, characterized by: The arc-shaped front disc and the arc-shaped rear disc are arranged with single-plate type blades between them, and the rear disc is provided with a hub disc bolt hole; the rear disc is detachably provided with a perpendicularity welding positioning block, and the perpendicularity welding positioning block is arranged in cooperation with the single-plate type blades.

2. A centrifugal fan single plate impeller structure according to claim 1, characterized in that: The outlet angle of the single-plate type blades is 46±1°.

3. A centrifugal fan single plate impeller structure according to claim 1, characterized in that: The single-plate type blades are 12 pieces and are distributed at equal angular velocities.

4. A centrifugal fan single plate impeller structure according to claim 1, characterized in that: The arc-shaped front disc is a front disc with an involute arc-shaped structure.

5. A centrifugal fan single plate impeller structure according to claim 1, wherein: The perpendicularity welding positioning block is spot-welded on the rear disc.

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