CN216447178U

CN216447178U - Backward centrifugal fan

Info

Publication number: CN216447178U
Application number: CN202123012606.1U
Authority: CN
Inventors: 刘爱瑜
Original assignee: Guangdong Sunwill Precising Plastic Co Ltd
Current assignee: Guangdong Sunwill Precising Plastic Co Ltd
Priority date: 2021-12-02
Filing date: 2021-12-02
Publication date: 2022-05-06
Anticipated expiration: 2031-12-02

Abstract

The application relates to the technical field of fans, in particular to a backward centrifugal fan which comprises a chassis, a wheel cover, a wheel hub, a cover cap and blades, wherein the blades are arranged between the wheel cover and the chassis, the middle part of the wheel cover is provided with an air inlet, the wheel hub is arranged in the middle part of one side, close to the wheel cover, of the chassis, the shape of the cover cap is matched with that of the wheel hub, the outer side of the cover cap is sleeved on the wheel hub, one side, away from the chassis, of the wheel hub is provided with an installation shaft, the installation shaft is used for externally connecting a driving shaft, the blades are arranged around the installation shaft at equal intervals, the blades are provided with flow guide structures, each flow guide structure is a blade knife, the blade knife is a convex edge arranged around the surface of each blade, and the convex edge is arranged along the air outlet direction of each blade; the guide structure is added on the blade, so that the guide can be accelerated, the surface of the blade is not easy to generate vortex, and the secondary flow loss of the blade is reduced, so that the overall flow loss of the fan is reduced, the work doing efficiency of the fan is increased, and the generation of pneumatic noise is reduced.

Description

Backward centrifugal fan

Technical Field

The utility model relates to the technical field of fans, in particular to a backward centrifugal fan.

Background

Centrifugal fans are generally used for air extraction or refrigeration devices such as air conditioners, refrigerators, exhaust fans and the like. With the continuous popularization of air conditioners, the noise of the air conditioner is more and more emphasized by users, the overall performance of the air conditioner is directly influenced by the noise, and further the market competitiveness of products is influenced, so that the problem of solving the noise of the air conditioner is always the key point and the difficulty of technical research of various air conditioner manufacturers at home and abroad.

The reason why the centrifugal fan generates noise can be roughly summarized as follows: 1. noise generated by blade rotation; 2. the vanes generate vortex flow to cause noise; 3. noise generated by turbulence; 4. the fan and the shell generate resonance noise.

Among the above-described causes of noise generation by the centrifugal fan, noise generated by vortex flow and turbulent flow accounts for a large part of the operating noise of the centrifugal fan. The conventional centrifugal fan blade is formed by stretching an airfoil, the pressure surface and the suction surface of the blade are smooth, when the centrifugal fan operates, the back surface of the blade can generate vortex, and the vortex can not only reduce the efficiency of the fan, but also generate noise.

SUMMERY OF THE UTILITY MODEL

In view of the above-mentioned drawbacks, the present invention provides a backward centrifugal fan, which can accelerate the flow guiding, thereby improving the work efficiency of the fan and reducing the generation of aerodynamic noise.

In order to achieve the purpose, the utility model adopts the following technical scheme:

the utility model provides a backward centrifugal fan, includes chassis, wheel cap, wheel hub, block and blade, the blade is located between wheel cap and the chassis, the middle part of wheel cap is equipped with the air intake, wheel hub locates the middle part that the chassis is close to wheel cap one side, the shape and the wheel hub adaptation of block, the block cover is located wheel hub's the outside, one side that wheel hub kept away from the chassis is equipped with the installation axle, the installation axle is used for external drive shaft, the blade is arranged around installation axle equidistance, be equipped with the water conservancy diversion structure on the blade, the water conservancy diversion structure is the blading, the blading is for surrounding the bead that sets up in the blade surface, the air-out direction setting of bead along the blade.

Preferably, the blade knife inclines from one side close to the hub to one side far away from the hub, the width of the blade knife is 3-6mm, and the thickness of the blade knife is 2-5 mm.

Preferably, the vane blade has a leading edge intersection point and a trailing edge intersection point, and the cambered surface of the vane blade is inclined from the leading edge intersection point to the trailing edge intersection point; the length of a connecting line of a leading edge intersection point and a trailing edge intersection point of the blade knife is defined as sd91, the maximum distance from a cambered surface of the blade knife to the connecting line of the leading edge intersection point and the trailing edge intersection point is defined as sd90, the relative curvature of the cambered surface is defined as L, L is sd90, 3/4/sd91, and L is more than or equal to 0.05 and less than or equal to 0.15.

Preferably, the inlet angle of the vane is between 10 ° and 30 ° and the outlet angle of the vane is between 5 ° and 20 °.

Preferably, the height of one side of the wheel cover positioned at the air inlet is an inlet height s1, the height of the outer side of the wheel cover far away from the air inlet is an outlet height s2, the ring surface of the wheel cover inclines downwards from the side of the air inlet to the outer side, and the inlet height s1 is greater than the outlet height s 2; the distance from the front edge intersection point to the chassis is defined as sd104, the distance from the rear edge intersection point to the chassis is defined as sd105, wherein 1/3s1 is not less than sd104 is not less than 3/4s1, 1/4s2 is not less than sd105 is not less than 2/3s 2.

Preferably, the number of the blading blades can be several, and when the number of the blading blades is more than one, the blading blades can be uniformly distributed at intervals in the vertical direction of the blade.

The technical scheme comprises the following beneficial effects:

the guide structure is added on the blade, so that the guide can be accelerated, the surface of the blade is not easy to generate vortex, the secondary flow loss of the blade is reduced, the overall flow loss of the fan is reduced, the work efficiency of the fan is increased, and the generation of pneumatic noise is reduced.

Drawings

FIG. 1 is a schematic overall structure of one embodiment of the present invention;

FIG. 2 is a schematic structural view of the hub of the present invention;

FIG. 3 is a parametric illustration of a blade of an embodiment of the present invention.

Wherein: 1. a chassis; 2. a wheel cover; 3. a hub; 4. capping; 5. a blade; 6. an air inlet; 7. installing a shaft; 8. a leaf cutter; 81. a leading edge intersection; 82. the trailing edge intersection.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on those shown in the drawings, and are merely for convenience of description and simplicity of description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention. Furthermore, features defined as "first" and "second" may explicitly or implicitly include one or more of the features for distinguishing between descriptive features, non-sequential, non-trivial and non-trivial.

In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The backward centrifugal fan according to the embodiment of the present invention is described below with reference to fig. 1 to 3, and includes a chassis 1, a wheel cover 2, a hub 3, a cap 4, and blades 5, where the blades 5 are disposed between the wheel cover 2 and the chassis 1, an air inlet 6 is disposed in the middle of the wheel cover 2, the hub 3 is disposed in the middle of the chassis 1 near one side of the wheel cover 2, the cap 4 is in a shape matched with the hub 3, the cap 4 is sleeved on the outer side of the hub 3, an installation shaft 7 is disposed on one side of the hub 3 away from the chassis 1, the installation shaft 7 is used for externally connecting a driving shaft, the blades 5 are arranged around the installation shaft 7 at equal intervals, a flow guide structure is disposed on the blades 5, the flow guide structure is a vane 8, the vane 8 is a convex rib disposed around the surface of the blade 5, and the convex rib is disposed along the air outlet direction of the blades 5.

Specifically, the outer diameters of the chassis 1 and the wheel cover 2 are the same, and the chassis 1, the wheel cover 2 and the blades 5, and the cap 4, the hub 3 and the chassis 1 are fixed into a whole through welding. When the fan is used, the mounting shaft 7 is connected with a driving shaft of an external driving motor, so that the whole fan rotates around the shaft under the driving of the driving shaft, airflow enters from the air inlet 6 and is discharged outwards along the radial direction of the fan from the gap between the wheel cover 2 and the chassis 1 and the blade 5.

The guide structure is added on the blade 5, so that the guide can be accelerated, the surface of the blade 5 is not easy to generate vortex, the secondary flow loss of the blade 5 is reduced, the overall flow loss of the fan is reduced, the work efficiency of the fan is increased, and the generation of pneumatic noise is reduced.

Preferably, the blade 8 inclines from the side close to the hub 3 to the side far from the hub 3, and the width of the blade 8 is 3-6mm, and the thickness is 2-5 mm.

Specifically, the blading knife 8 is a continuous and closed convex rib arranged around the blade 5, the arc surface of the convex rib is a smooth arc surface, the convex rib is inclined downwards from one side, closest to the middle of the fan, of the blade 5, and the outermost side, located on the fan, of the convex rib is the lowest point of the convex rib.

The blade knife 8 is added on the blade 5, different flow areas are formed between the wheel cover 2 and the chassis 1, and the effect of accelerating flow guiding is achieved, on the other hand, the blade knife 8 can reduce airflow flowing along the direction of the blade 5 to a certain extent, internal secondary flow loss of the flowing blade 5 is reduced, and overall flow loss of the fan is reduced; meanwhile, due to the characteristics of the air inlet mode of the traditional centrifugal fan, air pressure difference exists between the air inlet side of the fan and the chassis side of the fan, airflow is deviated from the air inlet side of the fan to the chassis side of the fan, and the air inlet attack angle can be reduced due to the existence of the vane knife 8, so that the work efficiency of the fan is increased, and the generation of aerodynamic noise is reduced.

Preferably, the vane blade 8 has a leading edge intersection 81 and a trailing edge intersection 82, and the arc surface of the vane blade 8 is inclined from the leading edge intersection 81 to the trailing edge intersection 82; the length of a connecting line of the leading edge intersection point 81 and the trailing edge intersection point 82 of the blade 8 is defined as sd91, the maximum distance from the cambered surface of the blade 8 to the connecting line of the leading edge intersection point 81 and the trailing edge intersection point 82 is defined as sd90, the relative curvature of the cambered surface is defined as L, L is sd90, 3/4/sd91, and L is more than or equal to 0.05 and less than or equal to 0.15.

Specifically, the front edge intersection 81 and the rear edge intersection 82 are respectively located at two sides of the blade 5, the horizontal height of the front edge intersection 81 is higher than that of the rear edge intersection 82, and the cambered surface is concave; in this embodiment, the highest point of the vane blade 8 on the side of the vane 5 close to the hub 3 is a leading edge intersection point 81, the lowest point of the vane blade 8 on the side of the vane 5 away from the hub 3 is a trailing edge intersection point 82, when the fan rotates, airflow flows to the trailing edge intersection point 82 along the leading edge intersection point 81 of the vane blade 8, and is finally discharged from the outer side of the fan, and the vane blade 8 has a flow guiding function, so that noise can be effectively reduced.

Preferably, the inlet angle of the vane blade 8 is between 10 ° and 30 °, and the outlet angle of the vane blade 8 is between 5 ° and 20 °.

Specifically, the inlet angle of the vane blade 8 is an angle between a tangent of the arc surface of the vane blade 8 at the leading edge intersection point 81 and a connecting line of the leading edge intersection point 81 and the trailing edge intersection point 82, and the outlet angle of the vane blade 8 is an angle between a tangent of the arc surface of the vane blade 8 at the trailing edge intersection point 82 and a connecting line of the leading edge intersection point 81 and the trailing edge intersection point 82. The entrance angle is denoted as sd88 and the exit angle is denoted as sd 89.

Preferably, the height of the side, located at the air inlet 6, of the wheel cover 2 is an inlet height s1, the height of the outer side, away from the air inlet 6, of the wheel cover 2 is an outlet height s2, the annular surface of the wheel cover 2 inclines downwards from the side, located at the air inlet 6, of the wheel cover 2, and the inlet height s1 is greater than the outlet height s 2; the distance from the front edge intersection 81 to the chassis 1 is defined as sd104, and the distance from the rear edge intersection 82 to the chassis 1 is defined as sd105, wherein 1/3s1 is not less than sd104 not less than 3/4s1, 1/4s2 is not less than sd105 not less than 2/3s 2.

Preferably, the number of the blades 8 is several, and when the number of the blades 8 is more than one, the blades can be evenly distributed at intervals in the vertical direction of the blade 5.

In particular, the blades 8 on the fan blade 5 may be provided in one or more number, and when the number is more than one, the flow guiding effect can be enhanced.

Other constructions and operation of a backward centrifugal fan according to embodiments of the present invention are known to those of ordinary skill in the art and will not be described in detail herein.

In the description herein, references to the description of the terms "embodiment," "example," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the utility model have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the utility model, the scope of which is defined by the claims and their equivalents.

Claims

1. The utility model provides a backward centrifugal fan which characterized in that: including chassis, wheel cap, wheel hub, block and blade, the blade is located between wheel cap and the chassis, the middle part of wheel cap is equipped with the air intake, wheel hub locates the middle part that the chassis is close to wheel cap one side, the shape and the wheel hub adaptation of block, the block cover is located wheel hub's the outside, one side that wheel hub kept away from the chassis is equipped with the installation axle, the installation axle is used for external drive shaft, the blade is arranged around installation axle equidistance, be equipped with the water conservancy diversion structure on the blade, the water conservancy diversion structure is the broach, the broach is for surrounding the bead that sets up in the blade surface, the air-out direction setting of bead along the blade.

2. The backward centrifugal fan of claim 1, wherein: the blade knife is inclined from one side close to the hub to one side far away from the hub, the width of the blade knife is 3-6mm, and the thickness of the blade knife is 2-5 mm.

3. The backward centrifugal fan according to claim 2, characterized in that: the blade knife is provided with a front edge intersection point and a rear edge intersection point, and the cambered surface of the blade knife inclines from the front edge intersection point to the rear edge intersection point; the length of a connecting line of a front edge intersection point and a rear edge intersection point of the blade is defined as sd91, the maximum distance from a cambered surface of the blade to the connecting line of the front edge intersection point and the rear edge intersection point is defined as sd90, the relative curvature of the cambered surface is defined as L, L is sd90 × 3/4/sd91, and L is more than or equal to 0.05 and less than or equal to 0.15.

4. A backward centrifugal fan according to claim 3, characterized in that: the inlet angle of the blade is between 10 degrees and 30 degrees, and the outlet angle of the blade is between 5 degrees and 20 degrees.

5. The backward centrifugal fan according to claim 4, wherein: the height of one side of the wheel cover positioned at the air inlet is inlet height s1, the height of the outer side of the wheel cover far away from the air inlet is outlet height s2, the ring surface of the wheel cover inclines downwards from one side of the air inlet to the outer side, and the inlet height s1 is larger than the outlet height s 2; the distance from the front edge intersection point to the chassis is defined as sd104, the distance from the rear edge intersection point to the chassis is defined as sd105, wherein 1/3s1 is not less than sd104 is not less than 3/4s1, 1/4s2 is not less than sd105 is not less than 2/3s 2.

6. The backward centrifugal fan of claim 1, wherein: the blade knives can be a plurality of, and when the number of the blade knives is more than one, the blade knives can be uniformly distributed at intervals in the vertical direction of the blade.