Cooling fan capable of preventing bearing from being corroded

Abstract

The utility model relates to a cooling fan capable of preventing a bearing from being corroded, which aims at solving the technical problem that the existing similar products lack the structural design that a stainless steel shaft core is adopted in a hub and the stainless steel shaft core at the bearing is combined with a ceramic coating. The radiating fan is characterized in that ceramic coatings are respectively arranged on the surfaces of at least two ends of a stainless steel shaft core in a hub of the radiating fan, an upper bearing and a lower bearing are respectively and fixedly arranged in a middle pipe of a frame body at the ceramic coatings, and the stainless steel shaft core is fixedly arranged in the middle pipe of the frame body through a clamping groove and a retaining ring at the tail end of one side of the lower bearing and a plastic gasket. A spring is arranged on the outer diameter of the stainless steel shaft core on the outer side of the upper bearing; two ends of the spring respectively abut against the upper bearing and the inner wall of the hub; a motor shell assembly is arranged in the hub, the magnet is arranged on the inner wall of a motor shell of the motor shell assembly, the stainless steel shaft core and a center shaft in the motor shell are riveted into a whole through a shaft sleeve, and one end of the spring abuts against the shaft sleeve. Therefore, a traditional metal shaft core or a full-ceramic shaft core is replaced by plating the ceramic coating on the surface of the stainless steel shaft core.

Description

Technical Field

[0001] This utility model relates to a cooling fan, specifically a cooling fan designed to prevent bearing corrosion. Background Technology

[0002] Cooling fans generally refer to fans used for cooling motherboard devices such as CPUs and graphics cards. Their main purpose is to conduct heat away and blow it into the surrounding air to achieve a cooling effect. Some cooling fans are currently used in charging piles in the new energy industry. As the power of charging piles increases, the speed of cooling fans also increases to meet the cooling requirements of the charging piles. The increased frequency of magnetic field switching inside the cooling fan leads to an increase in shaft voltage; in addition, the increased speed leads to a higher bearing temperature, causing the grease between the balls and the track to thin and its insulation and withstand voltage capabilities to deteriorate. The combination of these two factors makes it easier to generate shaft current in the circuit, and the bearing electro-corrosion problem is more serious. Therefore, some cooling fans use stainless steel shafts in their motor housings, such as the utility model "Die-cast Cooling Fan Motor Housing" disclosed in Chinese patent document CN210273656U, authorized on April 7, 2020.

[0003] Furthermore, research indicates that bearing electro-corrosion is primarily caused by shaft current, which originates from shaft voltage. The mechanisms underlying shaft voltage, shaft current, and bearing electro-corrosion in existing cooling fans are as follows: 1. Shaft Voltage: On one hand, during motor operation, the imbalance of the stator magnetic field generates an alternating electromagnetic field. This alternating electromagnetic field induces an AC voltage difference between the metal tube or metal shaft and the bearing. On the other hand, during motor operation, friction between the rotor assembly and air leads to the generation of static charge on the rotor assembly. The gradual accumulation of this static charge results in a DC voltage difference between the shaft and the bearing. These two voltage differences constitute the so-called shaft voltage. 2. Shaft Current: The metal shaft, bearing inner ring, balls and grease, bearing outer ring, and metal tube form a potential current loop. When the shaft voltage exceeds the insulation withstand voltage of the grease, it breaks down the grease, causing capacitive breakdown discharge and forming a current loop that generates shaft current. Shaft current causes surface fatigue damage to the balls and raceways, as well as gradual aging of the grease. 3. Bearing electro-corrosion: When the shaft current is large, spark discharge will occur, causing molten corrosion in the point contact area between the balls and the raceway (inner or outer ring). This is the phenomenon of bearing electro-corrosion. In addition, spark discharge can also accelerate the deterioration of lubricating grease, leading to premature bearing failure. The hazards caused by the above-mentioned bearing electro-corrosion are as follows: Bearing electro-corrosion will cause abnormal vibration of the bearing, deterioration of lubricating grease, and premature bearing failure, which in turn will increase the vibration and noise of the fan; in severe cases, it will burn out the bearing, causing the fan to seize up and lose its heat dissipation capacity. Summary of the Invention

[0004] To overcome the above-mentioned shortcomings, the purpose of this utility model is to provide a bearing corrosion-resistant cooling fan, thereby solving the technical problem that existing similar products lack a stainless steel shaft core inside the hub and a structural design that combines the stainless steel shaft core with a ceramic coating at the bearing. This objective is achieved through the following technical solution.

[0005] A bearing corrosion resistant cooling fan includes a frame, fan blades, a motor assembly, a circuit board, and a magnet. The magnet is disposed on the inner wall of the fan blade hub. The motor assembly and circuit board are integrated and fixedly mounted on the central tube of the frame. A stainless steel shaft at the central axis of the hub is inserted into and fixed to the central tube of the frame. The magnet on the inner wall of the hub and the coil wound on the silicon steel sheet on the plastic bracket of the motor assembly are positioned with a relative gap. The key structural design feature is that the stainless steel shaft at the hub has a ceramic coating on at least two ends. An upper bearing and a lower bearing are fixedly mounted inside the central tube of the frame at the ceramic coating location. The stainless steel shaft is fixed inside the central tube of the frame via a groove, a retaining ring, and a plastic gasket at one end of the lower bearing. A spring is mounted on the outer diameter of the stainless steel shaft outside the upper bearing, with both ends of the spring abutting against the upper bearing and the inner wall of the hub, respectively. This improves the corrosion resistance of the shaft through the stainless steel shaft and enhances the protection against electrical corrosion of the bearing through the ceramic coating on the stainless steel shaft at the upper and lower bearing locations.

[0006] The hub houses a motor housing assembly, with a magnet disposed on the inner wall of the motor housing assembly. A stainless steel shaft is riveted to the central shaft inside the motor housing via a bushing, and one end of the spring abuts against the bushing. The above describes an embodiment where the stainless steel shaft is housed within the hub via a bushing and a motor housing.

[0007] This utility model has a simple and reasonable structural design, is easy to assemble and produce, has good reliability, stability and safety, and a long service life. In particular, it effectively improves the anti-electrochemical corrosion ability of the shaft core and maintains the strength of the shaft core. It is suitable for use in anti-bearing corrosion cooling fans and for further improvement of similar products. Attached Figure Description

[0008] Figure 1 This is a cross-sectional structural diagram of the present invention.

[0009] Figure 2 yes Figure 1 A schematic diagram of the motor housing structure inside the wheel hub.

[0010] Attached figures and their names: 1. Frame, 101. Middle tube, 2. Fan blade, 201. Hub, 202. Motor housing assembly, 2021. Stainless steel shaft core, 2022. Bushing, 2023. Motor housing, 2024. Ceramic coating, 2025. Slot, 3. Spring, 4. Upper bearing, 5. Lower bearing, 6. Motor assembly, 7. Buckle, 8. Plastic gasket, 9. Circuit board. Implementation

[0011] The structure and use of this utility model will now be further described with reference to the accompanying drawings. Figures 1-2 As shown, the cooling fan includes a frame 1, fan blades 2, a motor assembly 6, a circuit board 9, and a magnet. The magnet is disposed on the inner wall of the hub 201 of the fan blades. The motor assembly and the circuit board are integrated and fixedly disposed in the central tube 101 of the frame. A stainless steel shaft core 2021 at the central shaft inside the hub is inserted into and fixed to the central tube of the frame. The magnet on the inner wall of the hub and the coil wound on the silicon steel sheet on the plastic bracket of the motor assembly are positioned with a relative gap. The stainless steel shaft core of the hub has a ceramic coating 2024 on at least two ends. An upper bearing 4 and a lower bearing 5 are fixedly disposed inside the central tube of the frame at the ceramic coating. The stainless steel shaft core is fixed inside the central tube of the frame through a slot 2025 at one end of the lower bearing, a buckle 7, and a plastic gasket 8. A spring 3 is disposed on the outer diameter of the stainless steel shaft core outside the upper bearing, with both ends of the spring abutting against the upper bearing and the inner wall of the hub, respectively. The hub is equipped with a motor housing assembly 202. The magnet is set on the inner wall of the motor housing 2023 of the motor housing assembly. The stainless steel shaft is riveted to the central shaft inside the motor housing through the bushing 2022. One end of the spring abuts against the bushing.

[0012] In summary, this cooling fan replaces the traditional metal shaft core with a ceramic coating on the surface of the stainless steel shaft core (the part where the bearing and shaft core meet). This utilizes the insulating properties of the ceramic coating to break the conductive circuit formed by the traditional metal shaft core, bearing, and copper tube, thus avoiding the generation of terminal voltage in principle and solving the problem of bearing electro-corrosion in existing similar products. It also avoids the use of a full ceramic shaft core, solving the problem of ceramic shaft cores being prone to breakage.

[0013] At the same time, the above structure completely improves the problem of bearing electro-corrosion in cooling fans. The structure is reasonably designed, easy to assemble and manufacture, effectively improves the resistance to electro-corrosion of the shaft core and maintains the strength of the shaft core, and increases the service life of the fan bearing, thereby improving the reliability of the fan.

Claims

1. A bearing corrosion resistant cooling fan, comprising a frame (1), fan blades (2), a motor assembly (6), a circuit board (9), and a magnet, wherein the magnet is disposed on the inner wall of the hub (201) of the fan blades, the motor assembly is integrally connected with the circuit board and fixedly disposed on the central tube (101) of the frame, a stainless steel shaft core (2021) at the central shaft inside the hub is inserted into and fixed to the central tube of the frame, and the magnet on the inner wall of the hub and the coil wound on the plastic bracket of the motor assembly are disposed with a relative gap; characterized in that The stainless steel shaft core (2021) of the hub (201) has ceramic coating (2024) on at least two ends. An upper bearing (4) and a lower bearing (5) are fixedly installed in the middle tube (101) of the frame (1) at the ceramic coating. The stainless steel shaft core is fixed in the middle tube of the frame through a slot (2025) at one end of the lower bearing, a buckle (7), and a plastic gasket (8). A spring (3) is provided on the outer diameter of the stainless steel shaft core outside the upper bearing. The two ends of the spring abut against the upper bearing and the inner wall of the hub, respectively.

2. The anti-bearing corrosion cooling fan according to claim 1, characterized in that... The hub (201) is provided with a motor housing assembly (202), the magnet is set on the inner wall of the motor housing (2023) of the motor housing assembly, the stainless steel shaft core (2021) is riveted to the central shaft inside the motor housing through the bushing (2022), and one end of the spring (3) abuts against the bushing.

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