Centrifugal blade and impeller

Abstract

The utility model relates to the technical field of centrifugal fan blades, in particular to a centrifugal blade. According to the impeller, in the extending direction of centrifugal blades, the suction surface of each centrifugal blade comprises a first arc surface and a second arc surface, the first arc surfaces and the second arc surfaces are in smooth transition, and transition inflection points are formed at the smooth transition positions; the bending directions of the first cambered surface and the second cambered surface are opposite; the extreme point of a conventional centrifugal blade is removed, when airflow flows through the suction surface of the centrifugal blade, it can be ensured that the airflow always moves forwards along the suction surface in the process that the airflow flows from the air inlet end and the air outlet end of the centrifugal blade, and therefore the phenomenon that the conventional centrifugal blade easily generates negative pressure near the suction surface of the air outlet end of the centrifugal blade is eliminated; airflow back suction is avoided, so that vortex pneumatic noise at the position is eliminated, and the vortex airflow of the whole suction surface is reduced; and meanwhile, the acting capacity of the centrifugal blades is improved, and the aerodynamic efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of centrifugal fan blades, in particular to a centrifugal blade, and in particular to an impeller. Background Art

[0002] The suction surface of a conventional centrifugal fan blade is generally arched. When air flows through the arched suction surface, due to inertia, a portion of the airflow will escape in a straight line along the tangent direction of the arched surface. The maximum value of the airflow escaping in the tangential direction is from the air inlet end to the maximum curvature of the suction surface or the middle of the arc surface. Therefore, this is the extreme point. After passing the extreme point of the arch, due to inertia, the airflow continues to flow forward along the original trajectory, rather than flowing along the suction surface behind the extreme point of the arched suction surface. This causes negative pressure near the suction surface section between the extreme point of the arched suction surface and the air outlet of the blade, and then airflow back-suction occurs, generating a vortex airflow behind the extreme point of the arched suction surface near the air outlet. On the one hand, it generates vortex aerodynamic noise, and on the other hand, it reduces the aerodynamic efficiency of the fan blade. Utility Model Content

[0003] The utility model provides a centrifugal blade and wheel assembly to solve the technical problems of high noise and low aerodynamic efficiency of centrifugal blades in the prior art;

[0004] The utility model provides a centrifugal blade, wherein the suction surface of the centrifugal blade includes a first arc surface and a second arc surface along the extension direction of the centrifugal blade, the first arc surface and the second arc surface are smoothly transitioned, and a transition inflection point is formed at the smooth transition;

[0005] The first arc surface and the second arc surface have opposite curvature directions;

[0006] The ends of the first curved surface and the second curved surface that are away from each other are the air inlet end and the air outlet end of the centrifugal blade respectively; a groove is provided at the connection between the suction surface and the air outlet end; and a toothed spoiler strip is provided in the groove.

[0007] Furthermore, the thickness of the air outlet end of the centrifugal blade is greater than three times the thickness of the air inlet end.

[0008] Furthermore, the transition inflection point is located in the middle of the suction surface and close to the intake end.

[0009] Furthermore, the pressure surface of the centrifugal blade is arched; the curvature direction of the pressure surface is the same as the curvature direction of the first arc surface.

[0010] Furthermore, the first curved surface is an outwardly convex curved surface.

[0011] Furthermore, the toothed spoiler strips are evenly arranged longitudinally at the intersection of the air outlet end and the suction surface; and the width of the toothed spoiler strips is greater than half of the depth of the toothed spoiler strips.

[0012] Furthermore, a spoiler wing is provided at a position of the suction surface close to the air outlet end; the spoiler wing is shuttle-shaped; and the edge of the spoiler wing close to the air outlet end is inclined toward the other edge.

[0013] The utility model provides an impeller, comprising an annular base and centrifugal blades mounted on the inner circumference of the annular base, wherein the centrifugal blades are evenly arranged in an array with the center of the annular base as the center;

[0014] The centrifugal blades are the centrifugal blades mentioned above.

[0015] Furthermore, the air outlet end edge line of each centrifugal blade is a circular arc line; the air outlet end edge line is adapted to the inner circumference of the annular base.

[0016] The utility model has at least the following beneficial effects:

[0017] The utility model provides a centrifugal blade, on which a transition inflection point is provided at a suction surface, and one end of the suction surface close to the air outlet end of the centrifugal blade gradually expands in a direction away from the suction surface, thereby removing the extreme point of a conventional centrifugal blade. When the airflow flows through the suction surface of the centrifugal blade, it can ensure that the airflow always moves along the suction surface during the flow from the air inlet end to the air outlet end of the centrifugal blade, thereby eliminating the phenomenon that conventional centrifugal blades are prone to generate negative pressure near the suction surface of the air outlet end of the centrifugal blade, avoiding the occurrence of airflow back-suction, thereby eliminating the vortex aerodynamic noise at the location, and reducing the overall vortex airflow of the suction surface; at the same time, the action ability of the centrifugal blade is also improved, and the aerodynamic efficiency is increased.

[0018] The utility model provides a centrifugal blade, which eliminates the shedding vortex formed by the separation of the outlet end through the toothed spoiler belt at the outlet end, and changes the flow direction of the air on the suction surface by adding a spoiler wing plate on the suction surface, destroying the air vortex originally generated on the suction surface, making the flow of the air smoother and more orderly, improving the air flow effect, and reducing the air flow noise.

[0019] The utility model provides an impeller, which eliminates the extreme point of conventional centrifugal blades by setting a transition inflection point on the suction surface of the centrifugal blades. It can ensure that the airflow always flows along the suction surface during the flow from the air inlet end to the air outlet end, thereby eliminating the phenomenon of negative pressure generated near the suction surface at the air outlet end of conventional centrifugal blades, avoiding the occurrence of airflow back-suction, thereby reducing vortex aerodynamic noise, and also improving the action ability of the centrifugal blades and increasing aerodynamic efficiency. At the same time, the shedding vortex is broken up by the saw teeth, weakening the size and capacity of the shedding vortex, thereby reducing noise and improving the user experience. The vortex is differentiated by adding spoiler winglets on the suction surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic structural diagram of a centrifugal blade according to the present invention;

[0021] Figure 2 This is a front view of a centrifugal blade according to the utility model;

[0022] Figure 3 This is a structural schematic diagram of an impeller according to the utility model;

[0023] In the figure: 1-suction surface, 2-pressure surface, 3-inflection point, 4-air inlet, 5-air outlet, 6-toothed spoiler strip, 7-spoiler wing, 8-annular base. DETAILED DESCRIPTION

[0024] 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 embodiments described 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 making creative efforts are within the scope of protection of the present invention.

[0025] See also Figure 1-Figure 2 The utility model provides a centrifugal blade; it includes a suction surface 1 and a pressure surface 2; the suction surface 1 and the pressure surface 2 are arranged opposite to each other. The side of the suction surface 1 and the pressure surface 2 close to the main shaft is the air inlet end 4; the side of the suction surface 1 and the pressure surface 2 away from the main shaft is the air outlet end 5; an inflection point 3 is provided on the suction surface 1, and the air outlet end 5 is trumpet-shaped. The side of the suction surface 1 close to the air outlet end 5 gradually expands in the direction away from the pressure surface, which can avoid the airflow back suction of the centrifugal blade of the utility model to a certain extent, thereby eliminating the vortex starting noise there, and at the same time improves the action ability of the centrifugal blade and increases the aerodynamic efficiency. The inflection point 3 divides the suction surface 1 into two arc segments, and the bending directions of the two arc segments are opposite, which can make the airflow on one side of the suction surface 1 move along the suction surface 1 as much as possible, thereby preventing the generation of vortex aerodynamic noise.

[0026] The air inlet end 4 of the present invention is configured as an arc. The air outlet end 5 can be configured as either a straight line or an arc. The arched pressure surface provides a simple structure and facilitates machining. Furthermore, the arc configuration of the air inlet end 4 can conform to the curvature of the impeller and improve overall aerodynamic performance.

[0027] The centrifugal blades of the present invention ensure that airflow flows forward along the blade surface during operation, avoiding the airflow separation phenomenon on the suction surface 1 side of conventional centrifugal blades. This prevents the generation of negative pressure near the suction surface 1 section between the arch extreme point and the outlet end 5, blocks the path for vortex airflow generation, and eliminates vortex aerodynamic noise near the outlet end 5. Furthermore, by eliminating unnecessary vortex airflow, power consumption is reduced, thereby improving the fan's aerodynamic performance.

[0028] A groove is formed at the junction of the suction surface 1 and the outlet end 5; a toothed spoiler strip 6 is provided within the groove; the toothed spoiler strips 6 are evenly arranged longitudinally at the intersection of the outlet end 5 and the suction surface 1; the width of the toothed spoiler strips 6 is greater than half the depth of the toothed spoiler strips 6. The toothed spoiler strips 6 at the outlet end 5 eliminate shedding vortices formed by the detachment of the outlet end 5.

[0029] A spoiler 7 is provided on the suction surface 1 near the air outlet 5. The width of the spoiler 7 on the side near the air inlet 4 and the side near the air outlet 5 is smaller than the width of the middle portion of the spoiler 7. The spoiler 7 is installed at a downward angle, specifically 17° to 20°. Adding the spoiler 7 to the suction surface 1 changes the direction of the airflow on the suction surface 1, destroying any vortices generated on the suction surface 1. This results in smoother and more orderly airflow, improved airflow performance, and reduced noise.

[0030] See also Figure 3 The present invention further provides an impeller comprising a plurality of the aforementioned centrifugal blades and an annular base 8; the annular base 8 is provided with a plurality of centrifugal blades; each centrifugal blade is arranged in a uniform annular array about the center of the annular base 8; the air outlet end 5 of each centrifugal blade is an arc; the radius of the air outlet end 5 is slightly smaller than the radius of the base 8; the air outlet end 5 is concentric with the annular base 8; and the air outlet end 5 conforms to the inner circumference of the annular base 8.

[0031] By setting a transition inflection point on the suction surface 1, the extreme point of the conventional centrifugal blade is removed, which ensures that the airflow always flows along the suction surface 1 during the flow from the air inlet end 4 to the air outlet end 5, thereby eliminating the phenomenon of negative pressure generated near the suction surface 1 at the air outlet end 5 of the conventional centrifugal blade, avoiding the occurrence of airflow back-suction, thereby reducing the vortex aerodynamic noise, and at the same time improving the ability of the centrifugal blade to act, and increasing aerodynamic efficiency. At the same time, the shedding vortex is broken up by the sawtooth, weakening the size and capacity of the shedding vortex, thereby reducing noise and improving the user experience. The vortex is differentiated by adding a spoiler wing 6 on the suction surface 1.

Claims

1. A centrifugal blade, characterized in that: Along the extension direction of the centrifugal blade, the suction surface (1) of the centrifugal blade includes a first arc surface and a second arc surface, the first arc surface and the second arc surface transition smoothly, and a transition inflection point (3) is formed at the smooth transition; The first arc surface and the second arc surface have opposite curvature directions; The ends of the first arc surface and the second arc surface that are away from each other are the air inlet end (4) and the air outlet end (5) of the centrifugal blade respectively; a groove is provided at the connection between the suction surface (1) and the air outlet end (5); and a toothed spoiler strip (6) is provided in the groove.

2. A centrifugal blade according to claim 1, characterized in that: The thickness of the air outlet end (5) of the centrifugal blade is greater than three times the thickness of the air inlet end (4).

3. The centrifugal blade according to claim 1, characterized in that: The transition inflection point (3) is located in the middle of the suction surface (1) and close to the air inlet end (4).

4. The centrifugal blade according to claim 1, characterized in that: The pressure surface (2) of the centrifugal blade is arched; the curvature direction of the pressure surface (2) is the same as the curvature direction of the first arc surface.

5. The centrifugal blade according to claim 1, characterized in that: The first arc surface is an outwardly convex arc surface.

6. The centrifugal blade according to claim 1, characterized in that: The toothed spoiler strips (6) are evenly arranged longitudinally at the intersection of the air outlet end (5) and the suction surface (1); the width of the toothed spoiler strips (6) is greater than half the depth of the toothed spoiler strips (6).

7. The centrifugal blade according to claim 1, characterized in that: A spoiler wing (7) is provided on the suction surface (1) near the air outlet end (5); the spoiler wing (7) is fusiform; and the spoiler wing (7) is inclined from one side edge near the air outlet end (5) toward the other side edge.

8. An impeller, characterized in that: It comprises an annular base (8) and centrifugal blades installed on the inner periphery of the annular base (8), wherein the centrifugal blades are evenly arranged in an array with the center of the annular base (8) as the center; The centrifugal blade is the centrifugal blade according to any one of claims 1 to 7.

9. An impeller according to claim 8, characterized in that; The edge line of the air outlet end (5) of each centrifugal blade is a circular arc line; the edge line of the air outlet end (5) is adapted to the inner circumference of the annular base (8).

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