Blade and hub connecting structure for reducing vibration of axial flow fan for air cooler

Abstract

The utility model discloses a blade and hub connecting structure for reducing vibration of an axial flow fan for an air cooler, which belongs to the technical field of axial flow fans for air coolers and comprises a bidirectional blade shaft, blades, a blade fixing component, a hub fixing component and a hub. The section shape and size of the two-way blade shaft in the axial direction of the fan are different from the section shape and size of the two-way blade shaft in the radial direction of the fan, different section resisting moments are formed, one end of the two-way blade shaft is connected with the hub through a hub fixing assembly, and the other end of the two-way blade shaft is connected with the blade through a blade fixing assembly; according to the blade and hub connecting structure for reducing vibration of the axial flow fan for the air cooler, the two-way blade shaft is adopted, vibration energy can be effectively absorbed, exciting force conducted to the hub by the blades is reduced, and then vibration conducted to a bearing and a framework is reduced.

Description

Technical Field

[0001] This utility model relates to the technical field of axial flow fans for air coolers, and in particular to a blade-hub connection structure for reducing vibration of axial flow fans for air coolers. Background Technology

[0002] Axial flow fans are devices that convert the mechanical energy provided by an electric motor or engine into the kinetic energy of airflow. They are widely used in equipment such as air coolers to provide airflow. Axial flow fans typically have evenly distributed front and rear guide vanes. However, axial flow fans used in air coolers are structurally limited and generally do not have front and rear guide vanes. They may also have unevenly distributed support structures arranged in the flow channel. These factors lead to air cooler fans typically generating higher mechanical vibrations.

[0003] Axial flow fans typically consist of multiple blades and a hub. The hub transfers mechanical energy to the blades, while the blades return various air reaction forces to the hub. Current blade-hub connections are generally rigid. To improve the connection strength, integral molding or direct welding are commonly used. For fans where these methods are inconvenient, flange bolts are often used. For fans requiring blade angle adjustment, a cylindrical blade shaft with a hub bushing is often used. These connection methods result in the forces acting on the blades being transferred more completely to the hub, thus affecting the vibration characteristics of the entire system.

[0004] Due to environmental and structural factors, air-cooled fans often have supporting structures on the impeller cross-section that result in uneven airflow. When the blades periodically pass over these supporting structures during rotation, they are subjected to a periodic excitation force, which is then transmitted to bearings and the frame—locations with high requirements for mechanical vibration. Excessive vibration can easily lead to premature bearing failure. Therefore, effectively reducing mechanical vibration has become one of the important research directions for improving the performance of axial fans used in air coolers. Utility Model Content

[0005] The purpose of this invention is to provide a blade-hub connection structure for reducing vibration of axial flow fans used in air coolers, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides a blade-hub connection structure for reducing vibration of an axial flow fan used in an air cooler. The structure includes a bidirectional blade shaft, blades, a blade fixing assembly, a hub fixing assembly, and a hub. The bidirectional blade shaft has different cross-sectional shapes and dimensions along the fan axial direction and along the fan radial direction, resulting in different section modulus moments. One end of the bidirectional blade shaft is connected to the hub through the hub fixing assembly, and the other end of the bidirectional blade shaft is connected to the blade through the blade fixing assembly.

[0007] Preferably, the section modulus of the bidirectional blade shaft in the axial direction of the fan is less than the section modulus of the bidirectional blade shaft in the radial direction of the fan.

[0008] Preferably, four bidirectional blade shafts are provided, and the four bidirectional blade shafts are connected to the hub in a cross shape.

[0009] Preferably, the blade fixing assembly includes a blade connecting block and a first bolt group, wherein the first bolt group passes through the blade connecting block and one end of the bidirectional blade shaft in sequence to connect the blade to the bidirectional blade shaft.

[0010] Preferably, the hub fixing assembly includes a hub connecting block and a second bolt group, wherein the second bolt group passes through the other end of the bidirectional blade shaft and the hub connecting block in sequence to connect the hub to the bidirectional blade shaft.

[0011] Therefore, the blade-hub connection structure of the present invention, which adopts the above-mentioned structure to reduce the vibration of the axial flow fan for air cooler, changes the cylindrical blade shaft in the cylindrical bushing connection method to a bidirectional blade shaft, which greatly reduces the section modulus of the blade shaft in the vibration direction of the fan blade. By greatly increasing the amplitude of the vibration generated by the excitation force on the blade itself, the vibration energy is absorbed, the excitation force transmitted from the blade to the hub is reduced, and the vibration transmitted to the bearing and frame is reduced. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of the blade-hub connection structure for reducing vibration of an axial flow fan for an air cooler according to the present invention.

[0013] Figure 2 This is an enlarged view of point A of the blade-hub connection structure for reducing vibration of an axial flow fan for an air cooler according to this utility model.

[0014] Figure 3 This is a schematic diagram of the blade and bidirectional blade shaft connection structure of the blade and hub connection structure for reducing vibration of an axial flow fan for an air cooler according to the present invention.

[0015] Figure 4 This is a structural diagram of a hub fixing assembly for a blade-hub connection structure to reduce vibration of an axial flow fan for an air cooler, according to the present invention.

[0016] Figure 5 This is a hub structure diagram of a blade-hub connection structure for reducing vibration of an axial flow fan for an air cooler, according to the present invention.

[0017] Reference numerals: 1. Bidirectional blade shaft; 2. Blade fixing assembly; 201. Blade connecting block; 202. First bolt group; 3. Blade; 4. Hub fixing assembly; 401. Hub connecting block; 402. Second bolt group; 5. Hub. Detailed Implementation

[0018] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments.

[0019] Unless otherwise defined, the technical or scientific terms used in this utility model shall have the ordinary meaning understood by one of ordinary skill in the art to which this utility model pertains. The terms "first," "second," and similar terms used in this utility model do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0020] Example

[0021] like Figures 1-5 As shown, a blade-hub connection structure for reducing vibration of an axial flow fan used in an air cooler includes a bidirectional blade shaft 1, blades 3, a blade fixing assembly 2, a hub fixing assembly 4, and a hub 5. The cross-sectional shape and dimensions of the bidirectional blade shaft 1 along the fan axial direction and along the fan radial direction are different, resulting in different section modulus moments. The section modulus moment of the bidirectional blade shaft 1 along the fan axial direction is smaller than that along the fan radial direction. In the fan axial direction, i.e., the main vibration direction of the blades 3, the section modulus moment is smaller, which is used to release the constraint of the hub 5 on the blades 3, absorb the impact energy of the blades 3 on the hub 5, and reduce the vibration transmitted from the blades 3 to the hub 5. In the fan radial direction, the section modulus moment is larger, which is used to resist the rotational bending moment generated when the fan rotates and reduce the deformation in this direction. One end of the bidirectional blade shaft 1 is connected to the hub 5 through the hub fixing assembly 4, and the other end of the bidirectional blade shaft 1 is connected to the blades 3 through the blade fixing assembly 2. The four bidirectional blade shafts 1 are connected to the hub 5 in a cross shape.

[0022] The blade fixing assembly 2 includes a blade connecting block 201 and a first bolt group 202. The first bolt group 202 passes through the blade connecting block 201 and one end of the bidirectional blade shaft 1 in sequence to connect the blade 3 to the bidirectional blade shaft 1.

[0023] The hub fixing assembly 4 includes a hub connecting block 401 and a second bolt group 402. The second bolt group 402 passes through the other end of the bidirectional blade shaft 1 and the hub connecting block 401 in sequence to connect the hub 5 to the bidirectional blade shaft 1, and fixes the bidirectional blade shaft 1 to the hub 5 by bolts.

[0024] Therefore, the present invention provides a blade-hub connection structure for reducing vibration of an axial flow fan for an air cooler, which adopts the above-mentioned structure and uses a bidirectional blade shaft. This structure can effectively absorb vibration energy, reduce the excitation force transmitted from the blades to the hub, and thus reduce the vibration transmitted to the bearings and frame.

[0025] Finally, it should be noted that the above embodiments are only preferred embodiments of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be covered within the protection scope of the present utility model.

Claims

1. A blade and hub connection structure for reducing vibration of an axial flow fan for an air cooler, characterized by: The application relates to a bidirectional blade shaft, a blade, a blade fixing assembly, a hub fixing assembly and a hub, wherein the bidirectional blade shaft has different cross-sectional shapes and sizes along the axial direction of a fan and along the radial direction of the fan, thereby forming different cross-sectional resisting moments; one end of the bidirectional blade shaft is connected with the hub through the hub fixing assembly; and the other end of the bidirectional blade shaft is connected with the blade through the blade fixing assembly.

2. The blade and hub connection structure for reducing vibration of an axial flow fan for an air cooler according to claim 1, characterized in that: The cross-sectional resisting moment of the bidirectional blade shaft along the axial direction of the fan is smaller than the cross-sectional resisting moment of the bidirectional blade shaft along the radial direction of the fan.

3. The blade and hub connection structure for reducing vibration of an axial flow fan for an air cooler according to claim 1, characterized in that: Four bidirectional blade shafts are arranged in a cross shape and connected with the hub.

4. The blade and hub connection structure for reducing vibration of an axial flow fan for an air cooler according to claim 1, characterized in that: The blade fixing assembly comprises a blade connecting block and a first bolt group, and the first bolt group sequentially penetrates through the blade connecting block and one end of the bidirectional blade shaft to connect the blade with the bidirectional blade shaft.

5. The blade and hub connection structure for reducing vibration of an axial flow fan for an air cooler according to claim 1, characterized in that: The hub fixing assembly comprises a hub connecting block and a second bolt group, and the second bolt group sequentially penetrates through the other end of the bidirectional blade shaft and the hub connecting block to connect the hub with the bidirectional blade shaft.

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