Axial flow fan

Abstract

The utility model provides an axial flow fan which is characterized in that a low concave structure group is arranged on the suction surface of a blade, low concave structure ridges surround the periphery of the low concave structure group, and at least one low concave structure ridge extends from a blade root starting point to a blade top end point. The weight of the blades of the axial flow fan can be effectively reduced, and meanwhile, the blades can be ensured to have small deformation when being stressed, so that the production cost of the fan and the motor load are reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to a fan technology field, concretely relates to a low pressure air supply's axial flow fan. BACKGROUND

[0002] At present, axial flow fan is widely used in the air supply system of air conditioner outdoor unit for improving the heat dissipation efficiency of heat exchanger because of its large air volume and low noise. When working, the blade of axial flow fan will be subjected to centrifugal force generated by rotation and pressure of air flow. Therefore, the fan blade needs to have strength to resist external load, and at the same time, the deformation of the blade under stress needs to be small to maintain the aerodynamic shape of the fan blade. In order to meet the requirements, the axial flow fan blade of the prior art adopts the technical scheme of overall thickening, which makes the weight of the axial flow fan larger. The increase of the weight of the axial flow fan increases the production cost of the axial flow fan and also increases the load of the matched fan motor.

[0003] In summary, the scheme of effectively reducing the weight of the axial flow fan blade while ensuring that the deformation of the blade under stress is small to reduce the production cost of the fan and the load of the motor is an urgent problem to be solved by the technical developers in the field. SUMMARY

[0004] Therefore, the utility model mainly solves the technical problem of providing an axial flow fan which can effectively reduce the weight of the axial flow fan blade while ensuring that the deformation of the blade under stress is small to reduce the production cost of the fan and the load of the motor.

[0005] In order to solve the above technical problems, one technical scheme of the utility model is to provide an axial flow fan. The axial flow fan comprises a hub and a plurality of blades, the number of blades is two or more than two, and the plurality of blades are connected to the hub. The axial flow fan is generally integrally formed. The outer contour of the blade has a blade root, a blade tip, a leading edge and a trailing edge, and the closed curved surface has a pressure surface and a suction surface. The characteristic is that the suction surface of the blade has a low concave structure group, the low concave structure group is surrounded by a low concave structure ridge, and at least one low concave structure ridge extends from the starting point of the blade root to the end point of the blade tip. The low concave structure group is recessed from the suction surface to the pressure surface and does not penetrate the blade. The pressure surface is the surface with higher surface pressure of the blade when the axial flow fan rotates. The suction surface is the surface with lower surface pressure of the blade when the axial flow fan rotates.

[0006] Further, the low concave structure group is completely located inside the area surrounded by the blade root, the blade tip, the leading edge and the trailing edge of the blade. The area S1 of the low concave structure group and the area S2 of the suction surface of the blade have the following relationship:

[0007] 0.2 < S1 / S2 < 0.6.

[0008] Further, the low concave structure group is composed of two or more low concave structures, each low concave structure presents a triangular structure, and each low concave structure is surrounded by a low concave structure ridge, and the width L of the low concave structure ridge and the blade thickness τ at the corresponding position satisfy the following relationship:

[0009] 1 < L / τ < 8

[0010] Further, the recess depth of the low concave structure is not the same in each region, and the distribution rule is that the recess depth of the low concave structure gradually decreases from the blade root to the blade top, and the recess depth of the low concave structure gradually decreases from the leading edge to the trailing edge.

[0011] Further, the recess depth H of the low concave structure and the blade thickness τ at the corresponding position satisfy the following relationship: 0.2 < H / τ < 0.8

[0012] The utility model has the following advantages:

[0013] The utility model provides a axial flow fan. The axial flow fan includes low concave structure group on suction surface of blade, low concave structure group is surrounded by low concave structure ridge, and at least one low concave structure ridge extends from blade root starting point to blade top terminal point, because it adopts similar building frame structure, does not need to thicken blade as a whole, can effectively reduce axial flow fan blade weight, can guarantee that blade has smaller deformation when being stressed simultaneously, thereby reducing fan production cost and motor load. BRIEF DESCRIPTION OF DRAWINGS

[0014] The above and additional features and advantages of the utility model will become apparent and easy understood by the following description of the embodiments with reference to the following drawings. The embodiments are illustrated by way of example in the accompanying drawings, in which like references indicate similar elements or elements with the same or similar functionality throughout the several views. The embodiments described below are exemplary and are intended to explain the utility model, but cannot be understood as limiting the utility model.

[0015] Wherein:

[0016] Figure 1 It is prior art axial flow fan suction surface structure schematic diagram;

[0017] Figure 2 It is axial flow fan suction surface structure schematic diagram of the utility model embodiment;

[0018] Figure 3 It is side view of axial flow fan of the utility model embodiment;

[0019] Figure 4 It is Figure 2 The sectional structure of the axial flow fan A-A direction shown in the structure schematic diagram of one embodiment;

[0020] Reference signs: axial flow fan 1, blade 2, blade root 2.1, blade root starting point 2.1.1, blade root ending point 2.1.2, blade tip 2.2, blade tip starting point 2.2.1, blade tip ending point 2.2.2, leading edge 2.3 and trailing edge 2.4, low structure group 2.5, low structure 2.5.x, low structure fence 2.6, hub 3, shaft hole 3.1, suction surface SS, pressure surface PS. DETAILED DESCRIPTION

[0021] In order to solve the technical problem of the large weight of the axial flow fan caused by the overall thickening of the blade of the axial flow fan in the prior art, the embodiment of the utility model provides an axial flow fan, which is characterized in that the suction surface of the blade has a low structure group, the low structure group is surrounded by a low structure fence, and at least one low structure fence extends from the blade root starting point to the blade tip ending point, and the low structure group is recessed from the suction surface to the pressure surface and does not penetrate the blade. The following is described in detail.

[0022] REFERENCE Figures 2 to 3 In some embodiments of the utility model, the axial flow fan 1 comprises a hub 3 and a plurality of blades 2, the number of blades 2 is two or more, the plurality of blades 2 are connected to the hub 3, and the axial flow fan 1 is generally integrally formed. The shaft hole 3.1 of the hub 3 is connected with the rotating shaft of the motor, when the motor works, the axial flow fan 1 rotates synchronously, and the rotating direction of the axial flow fan 1 of the embodiment is counterclockwise.

[0023] The outer contour of the blade 2 has a blade root 2.1, a blade tip 2.2, a leading edge 2.3 and a trailing edge 2.4. The blade root 2.1 is close to the hub 3, the blade tip 2.2 is away from the hub 3, the leading edge 2.3 is towards the rotating direction, and the trailing edge 2.4 is away from the rotating direction. The intersection of the blade root 2.1 and the leading edge 2.3 is the blade root starting point 2.1.1, and the intersection of the blade root 2.1 and the trailing edge 2.4 is the blade root ending point 2.1.2. The intersection of the blade tip 2.2 and the leading edge 2.3 is the blade tip starting point 2.2.1, and the intersection of the blade tip 2.2 and the trailing edge 2.4 is the blade tip ending point 2.2.2.

[0024] Further, the curved surface enclosed by the blade root 2.1, the blade tip 2.2, the leading edge 2.3 and the trailing edge 2.4 has a pressure surface PS and a suction surface SS, the pressure surface PS and the suction surface SS are defined according to the height of the surface pressure when the axial flow fan 1 rotates, wherein the pressure surface PS is the outer surface with higher blade surface pressure when the axial flow fan 1 rotates; and the suction surface SS is the outer surface with lower blade surface pressure when the axial flow fan 1 rotates.

[0025] When the axial fan 1 rotates, the fan parts are subjected to the combined action of centrifugal force and air flow pressure, causing the blade 2 to deform, wherein the blade tip starting point 2.2.1 is deformed to tilt towards the pressure surface PS, and the blade tip ending point 2.2.2 is deformed to press down towards the suction surface SS. This deformation changes the aerodynamic profile of the fan blade 2. To solve this technical problem, the prior art adopts the scheme of thickening the entire axial fan blade 2, which makes the axial fan 1 heavy. The weight of the axial fan directly relates to the production cost of the axial fan, and also affects the load of the matched fan motor.

[0026] Therefore, the axial fan 1 of the embodiment has a low concave structure group 2.5 on the suction surface SS of the blade 2. The low concave structure group 2.5 is recessed from the suction surface SS to the pressure surface PS and does not penetrate the blade 2. As can be seen, the concave structure group 2.5 on the suction surface SS of the blade 2 removes the material at the local position of the blade, thereby reducing the weight of the blade 2.

[0027] Further, the low concave structure group 2.5 is completely located inside the area surrounded by the blade root 2.1, the blade tip 2.2, the leading edge 2.3 and the trailing edge 2.4 of the blade 2. The area S1 of the low concave structure group 2.5 and the area S2 of the suction surface SS of the blade have the following relationship: 0.2

[0028] Further, the low concave structure group 2.5 is composed of two or more low concave structures 2.5.1, 2.5.2,... Each low concave structure 2.5.x has an area S a , S b ... Therefore, the relationship between the area S1 of the low concave structure group 2.5 and the area of each low concave structure 2.5.x is: S1 = S a + S b +...

[0029] Further, each low concave structure 2.5.x has a triangular structure, which makes it more stable. Each low concave structure 2.5.x is surrounded by low concave structure walls 2.6, and at least one low concave structure wall 2.6 extends from the blade root starting point 2.1.1 to the blade tip ending point 2.2.2. Due to the design of the low concave structure wall 2.6, the overall structure of the blade is similar to the frame structure of a building, the edges and the main stress area in the middle are strengthened, and the remaining areas are thinned. Therefore, the blade does not need to be thickened as a whole, thereby having a small deformation amount when the blade is stressed, and ensuring that the aerodynamic profile of the fan blade only changes slightly.

[0030] Further, referring to Figure 4 Further, the width L of the low-recess-structure-surrounding ridge 2.6 around each low-recess structure 2.5.x has the following relationship with the blade thickness τ at the corresponding position: 1 < L / τ < 8. In the embodiment, the width L of the low-recess-structure-surrounding ridge 2.6 around each low-recess structure 2.5.x preferably has the following relationship with the blade thickness τ at the corresponding position: 4 < L / τ < 6. Reasonable increase of the material at the blade frame position can effectively improve the strength and rigidity of the axial flow fan and avoid deformation.

[0031] Further, the recess depth of each low-recess structure 2.5.x is not the same in different regions, and the distribution rule is that the recess depth of the low-recess structure gradually decreases from the blade root 2.1 to the blade tip 2.2 of the blade 2, and the recess depth of the low-recess structure gradually decreases from the leading edge 2.3 to the trailing edge 2.4.

[0032] Further, the recess depth H of each low-recess structure 2.5.x has the following relationship with the blade thickness τ at the corresponding position: 0.2 < H / τ < 0.8. In the embodiment, the recess depth H of each low-recess structure 2.5.x has the following relationship with the blade thickness τ at the corresponding position: 0.5 < H / τ < 0.7. Reasonable increase of the recess depth can effectively reduce the use cost of the blade material.

[0033] According to the embodiment of the utility model provides a kind of axial flow fan.The axial flow fan includes low-recess structure group on suction surface of blade, low-recess structure group four around low-recess structure ridge, and at least one low-recess structure ridge extends from blade root starting point to blade tip end point, since it adopts similar building frame structure, it does not need to thicken blade as a whole, can effectively reduce the weight of axial flow fan blade, while it can guarantee that blade has smaller deformation amount when stressed, to reduce the production cost of fan and motor load.

[0034] The technical solution includes but is not limited to the above implementation cases, and any method in the technical solution can be derived by simple reasoning, and the new solution obtained by derivation is also regarded as the method of the technical solution.

[0035] The above is only a specific implementation of the utility model, and does not limit the utility model, and any modification, equivalent replacement and improvement made within the spirit and principles of the utility model shall be included in the protection scope of the utility model. It should be pointed out that, for ordinary skilled persons in the technical field, without departing from the technical principles of the utility model, a number of improvements and modifications can be made, and these improvements and modifications shall be regarded as the protection scope of the utility model.

Claims

1. An axial flow fan characterised in that: The hub and the plurality of blades; the outer profile of the blade has a blade root, a blade tip, a leading edge and a trailing edge, the closed curved surface has a pressure surface and a suction surface, and a low concave structure group is arranged on the suction surface of the blade, the low concave structure group is surrounded by a low concave structure ridge, and at least one low concave structure ridge extends from the starting point of the blade root to the ending point of the blade tip, and the low concave structure group is recessed from the suction surface to the pressure surface and does not penetrate the blade.

2. An axial fan as claimed in claim 1, characterized in that: The low concave structure group is completely located in the area surrounded by the blade root, the blade tip, the leading edge and the trailing edge, and the area of the low concave structure group S1 and the area of the suction surface of the blade S2 have the following relationship: 0.2 3. An axial fan as claimed in claim 1, characterized in that: The low concave structure group is composed of two or more low concave structures, each low concave structure presents a triangular structure, each low concave structure is surrounded by a low concave structure ridge, and the width L of the low concave structure ridge and the thickness τ of the blade at the corresponding position have the following relationship: 1 4. An axial fan as claimed in claim 1, characterized in that: The recess depth of the low concave structure is not the same in each area, and the distribution rule is that the recess depth of the low concave structure gradually decreases from the blade root to the blade tip and gradually decreases from the leading edge to the trailing edge.

5. An axial fan as claimed in claim 1, characterized in that: The recess depth H of the low concave structure and the thickness τ of the blade at the corresponding position have the following relationship: 0.2

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