Oil bearing fan oil leakage prevention structure

Abstract

An oil-impregnated bearing fan anti-leakage structure includes a fan frame center column with a circular mounting groove on its end face, within which a rotating body is rotatably mounted; the bearing includes a bearing and a rotating shaft, with the bearing and groove having a transition fit; a stepped groove is provided on the inner wall of the groove port of the fan frame center column, into which an elastic Mylar sheet is embedded, capable of elastic deformation along the axial direction, with its central hole having a transition fit with the rotating shaft; a mounting sleeve is interference-fitted onto the outer wall of the fan frame center column, with a sealing plate at the bottom end of the mounting sleeve, sealing the groove port and providing a through hole for the rotating shaft to pass through, with an O-ring between the inner wall of the through hole and the outer wall of the rotating shaft. This structure utilizes the axial elastic deformation of the Mylar sheet, allowing the weight of the lubricating oil to hold the Mylar sheet in place when the fan is inverted, adaptively increasing the sealing pressure, and forming a double seal with the O-ring, effectively preventing oil leakage and ensuring high reliability.

Description

Technical Field

[0001] This application relates to the technical field of cooling fans, and more specifically, it relates to an oil-proof structure for an oil-impregnated bearing fan. Background Technology

[0002] Oil-impregnated bearing fans are widely used in the cooling systems of electronic devices due to their compact structure, smooth operation, and low cost. Traditional oil-impregnated bearing fans typically consist of a fan frame, a central column, and a bearing mounted within the central column. To ensure long-term stable operation of the bearing, lubricating oil needs to be impregnated inside the bearing to form an oil film between the bearing and the inner wall of the central column, reducing friction and wear.

[0003] In practical applications, the installation orientation of electronic devices is becoming increasingly diversified. Especially in some miniaturized, highly integrated devices, cooling fans often need to be installed upside down, i.e., below the central column port slot of the fan frame. In this upside-down installation state, traditional oil-impregnated bearing fans face a prominent oil leakage problem: under its own gravity, the lubricating oil gradually accumulates at the lower end opening of the bearing and slowly seeps out along the gap between the bearing and the central column port, eventually dripping into the inside of the equipment, causing contamination of electronic components, deterioration of insulation performance, or even short-circuit failures.

[0004] To address oil leakage, related technologies include installing O-rings or oil seals at the bearing ports, utilizing their elastic deformation to press against the shaft surface for dynamic sealing; or attaching ordinary circular diaphragms or gaskets to the ports of the fan frame's central column to prevent oil leakage. However, these structures still have significant shortcomings in practical applications: O-rings or oil seals are prone to failure due to wear and aging after long-term operation; and ordinary diaphragms or gaskets are mostly fixed horizontally or at an angle. In an inverted state, lubricating oil will still accumulate at the interface between the seal and the shaft under gravity. When the liquid level pressure exceeds the sealing capacity, oil will still rise along the shaft surface or seep out from the edge of the diaphragm. The oil leakage problem is particularly severe when changes in fan speed and temperature cause fluctuations in internal air pressure. Summary of the Invention

[0005] To address the issue of oil leakage when an oil-impregnated bearing fan is installed upside down, this application provides an oil-leakage-proof structure for an oil-impregnated bearing fan.

[0006] An oil-impregnated bearing fan oil-proof structure includes a fan frame center column. A circular mounting groove is recessed on the end face of the center column, and a rotating body is rotatably mounted within the circular mounting groove. The rotating body includes a bearing that matches the circular mounting groove and a rotating shaft that passes through the center of the bearing. The bearing is in transition fit with the circular mounting groove. One end of the rotating shaft protrudes from the port of the circular mounting groove. A stepped groove is provided on the inner wall of the port of the circular mounting groove on the center column. A circular Mylar sheet is embedded in the stepped groove. The Mylar sheet is an elastic thin sheet structure. The Mylar sheet undergoes elastic deformation along the axial direction within the stepped groove. The Mylar sheet has a central hole through which the rotating shaft passes and is in transition fit with the central hole. An interference fit is provided on the outer wall of the center column, and a sealing plate is provided at the bottom end of the mounting sleeve. The sealing plate closes the port of the circular mounting groove and has a through hole for the rotating shaft to pass through. An O-ring is provided between the inner wall of the through hole and the outer wall of the rotating shaft.

[0007] By adopting the above technical solution, a flexible Mylar plate is designed, allowing it to undergo axial elastic deformation within the stepped groove. When the fan is installed upside down, the lubricating oil accumulated at the port of the circular mounting groove presses down on the Mylar plate under its own weight, causing axial elastic deformation. This increases the contact pressure between the inner wall of the Mylar plate's central hole and the outer wall of the shaft, achieving an adaptive seal. The more lubricating oil accumulates and the greater the weight, the greater the sealing pressure, effectively avoiding the oil leakage problem of traditional seals in the upside-down state due to the inability to utilize gravity. Simultaneously, the O-ring at the sealing plate forms a double seal, and the interference fit of the mounting sleeve enhances the overall structural stability, significantly improving the reliability of oil leakage prevention.

[0008] Preferably, the depth of the stepped groove is greater than the thickness of the Mylar sheet, and an axial gap is left between the bottom surface of the stepped groove and the Mylar sheet, the size of which is 0.05mm to 0.2mm.

[0009] By adopting the above technical solution, the depth of the stepped groove is greater than the thickness of the Mylar sheet, and an axial gap of 0.05mm to 0.2mm is left between the bottom surface and the Mylar sheet. This provides a controllable elastic deformation space for the Mylar sheet under the weight of the lubricating oil, ensuring that the Mylar sheet can generate sufficient deformation to press the rotating shaft, while preventing excessive displacement or instability of the Mylar sheet due to excessive gap. Thus, while ensuring the sealing effect, the positioning accuracy and long-term working stability of the Mylar sheet are maintained.

[0010] Preferably, the Mylar sheet is made of polyester film, polyimide film, or polytetrafluoroethylene film.

[0011] By adopting the above technical solutions, Mylar sheets are made of polyester film, polyimide film, or polytetrafluoroethylene film. These materials all have excellent elasticity, oil resistance, high and low temperature resistance, and low coefficient of friction. They can be immersed in the lubricating oil environment for a long time without swelling, aging, or cracking. This ensures that the Mylar sheet maintains its elastic deformation ability and sealing performance throughout the entire life cycle of the fan, avoiding the defects of rubber seals that are easy to wear and age.

[0012] Preferably, the inner wall of the mounting sleeve is provided with an air guide groove that penetrates through it.

[0013] By adopting the above technical solution, a through-hole air guide groove is set in the inner wall of the mounting sleeve, which can effectively balance the air pressure between the circular mounting groove inside the fan and the external environment. This avoids internal air pressure fluctuations caused by fan operation heat or changes in ambient temperature, thereby preventing the air pressure difference from "drawing out" or "blowing out" the lubricating oil from the sealing gap. At the same time, it also avoids the air pressure fluctuation from interfering with the elastic deformation state of the Mylar film, further enhancing the stability of the oil leakage prevention structure.

[0014] Preferably, the outer wall of the bearing is evenly distributed with a plurality of oil guide grooves, the plurality of oil guide grooves are evenly distributed around the center of the bearing, and each oil guide groove extends along the axial direction of the bearing, and the two ends of the oil guide groove extend to the two end faces of the bearing respectively.

[0015] By adopting the above technical solution, oil guide grooves extending axially to both ends are evenly arranged on the outer wall of the bearing, which helps the lubricating oil to be evenly distributed between the outer wall of the bearing and the inner wall of the circular mounting groove, forming a stable oil film to reduce friction and wear.

[0016] Preferably, the end of the fan frame central column away from the circular mounting groove is connected to the fan frame, and the end of the rotating shaft extending out of the circular mounting groove is connected to the fan blade structure.

[0017] By adopting the above technical solution, the connection relationship between the central column of the fan frame and the fan frame, as well as the connection relationship between the rotating shaft and the fan blade structure, are clarified. This provides a complete installation carrier and power output path for the oil leakage prevention structure, ensuring that the rotating body and Mylar plate sealing structure can work stably when the rotating shaft drives the fan blade to rotate. The structure is compact and easy to assemble.

[0018] Preferably, the outer wall of the mounting sleeve is provided with an inner stator, the inner stator is connected to a circuit board, the circuit board is fixed to the fan frame, and the fan blade structure is connected to a rotor that matches the inner stator.

[0019] By adopting the above technical solution, the inner stator, circuit board, and rotor connected to the fan blade structure are set on the outer wall of the mounting sleeve, and the motor drive system and the oil leakage prevention structure are combined: the mounting sleeve serves as both the mounting base of the stator and the fixing structure of the sealing component, reducing the number of additional parts.

[0020] Preferably, the fan frame includes a frame body and a connecting frame disposed on one end face of the frame body. The central column of the fan frame is located at the center inside the frame body and is connected to the connecting frame. The fan blade structure includes a hub and a plurality of blades disposed on the outer wall of the hub. The plurality of blades are evenly arranged around the center of the hub. A receiving groove is recessed in the center of the hub. The rotating shaft is connected to the center of the bottom of the receiving groove of the hub. The central column of the fan frame is located in the receiving groove. The rotor is connected to the inner wall of the receiving groove and is aligned with the inner stator.

[0021] By adopting the above technical solution, the central column of the fan frame is placed in the receiving groove of the hub, and the rotor is installed on the inner wall of the receiving groove and aligned with the inner stator. This structure ensures the coaxiality of the rotating shaft and the fan blade, reduces operating vibration, and at the same time, the receiving groove surrounds and protects the central column of the fan frame, which helps to prevent external dust from entering the sealing area and indirectly improves the oil leakage prevention effect.

[0022] Preferably, a semi-circular connector is provided at the end of the rotating shaft away from the circular mounting groove port, a limiting groove is provided at the bottom of the circular mounting groove of the fan frame center post, the semi-circular connector is inserted into the limiting groove, a limiting piece is fixedly connected to the fan frame center post at the opening of the limiting groove, the limiting piece is provided with a through hole, and the diameter of the through hole is configured to be larger than the diameter of the rotating shaft and smaller than the diameter of the semi-circular connector.

[0023] By adopting the above technical solution, a semi-circular connector is set at the end of the shaft, and a limiting groove and a limiting plate are set at the bottom of the central column of the fan frame. The through hole diameter of the limiting plate is larger than the diameter of the shaft but smaller than the diameter of the semi-circular connector, which realizes the reliable axial limiting of the shaft. This not only prevents the shaft from coming out of the rotating body, but also does not restrict the free rotation of the shaft. The limiting structure, together with the Mylar plate and O-ring at the port, ensures that the bottom limiting prevents the shaft from moving, and the top sealing ensures that the lubricating oil does not leak out, which significantly improves the operating safety of the fan under inverted or vibrating conditions.

[0024] The beneficial technical effects of this application are as follows: By incorporating an elastic Mylar plate that can undergo axial elastic deformation within the stepped groove, when the fan is installed upside down, the lubricating oil accumulated at the port of the circular mounting groove will press down on the Mylar plate under its own weight, causing axial elastic deformation. This increases the contact pressure between the inner wall of the Mylar plate's central hole and the outer wall of the shaft, achieving an adaptive seal. The more lubricating oil accumulates and the greater the weight, the greater the sealing pressure, effectively avoiding the problem of oil leakage caused by traditional seals being unable to utilize gravity in an upside-down state. Simultaneously, the O-ring at the sealing plate forms a double seal, and the interference fit of the mounting sleeve enhances the overall structural stability, significantly improving the reliability of oil leakage prevention. Attached Figure Description

[0025] Figure 1 This is an overall schematic diagram of an oil-impregnated bearing fan oil leakage prevention structure according to this embodiment.

[0026] Figure 2 This is a cross-sectional view of an oil-impregnated bearing fan oil leak prevention structure according to this embodiment.

[0027] Figure 3 This is a schematic diagram of the rotating body in this embodiment.

[0028] Figure 4 This is a schematic diagram of the mounting sleeve and inner stator in this embodiment.

[0029] Figure 5 This is a schematic diagram of the structure of the Mylar sheet and O-ring in this embodiment.

[0030] Reference numerals: 1. Fan frame center column; 11. Circular mounting groove; 12. Step groove; 13. Limiting groove; 14. Limiting piece; 2. Rotating body; 21. Bearing; 211. Oil guide groove; 22. Rotating shaft; 221. Semi-circular connector; 3. Mylar plate; 4. Mounting sleeve; 41. Sealing plate; 42. Air guide groove; 5. O-ring; 6. Fan frame; 61. Frame body; 62. Connecting frame; 7. Fan blade structure; 71. Hub; 72. Blade; 8. Inner stator; 9. Circuit board; 100. Rotor; Detailed Implementation

[0031] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] Reference Figure 1-2 An oil-impregnated bearing fan anti-leakage structure includes a fan frame center column 1. A circular mounting groove 11 is recessed inward on one end face of the fan frame center column 1 to accommodate and position a rotating body 2. The rotating body 2 includes a bearing 21 and a rotating shaft 22 passing through the center of the bearing 21. The rotating shaft 22 and the bearing 21 are fixed by an interference fit through an inner hole in the bearing 21. The outer wall size of the bearing 21 matches the inner wall size of the circular mounting groove 11, and the two are assembled by a transition fit, so that the bearing 21 can be stably installed inside the circular mounting groove 11. The rotating shaft 22 passes through the center hole of the bearing 21, and one end of the rotating shaft 22 protrudes outward from the end of the circular mounting groove 11.

[0033] Reference Figure 2 and Figure 5To form the first oil-proof seal at the port, a stepped groove 12 is further machined on the inner wall of the circular mounting groove 11 of the fan frame center column 1. A circular Mylar sheet 3 is embedded inside the stepped groove 12. The Mylar sheet 3 adopts an elastic sheet structure, such as being made of polyester film, polyimide film, or polytetrafluoroethylene film, which have good oil resistance and elasticity. A central hole is opened in the center of the Mylar sheet 3, through which the rotating shaft 22 passes during assembly, and the inner wall of the central hole forms a transition fit with the outer wall of the rotating shaft 22. More importantly, the Mylar sheet 3 is not completely compressed and fixed in the stepped groove 12, but is allowed to undergo a certain amount of elastic deformation along the axial direction of the fan frame center column 1. Specifically, the depth of the stepped groove 12 is set to be greater than the thickness of the Mylar sheet 3 itself, and an axial gap is reserved between the bottom surface of the stepped groove 12 and the Mylar sheet 3. The size of the axial gap can be controlled between 0.05 mm and 0.2 mm. This gap provides the Mylar sheet 3 with controllable elastic deformation space. When the fan is installed upside down, with the port of the central column 1 of the fan frame facing downwards, the lubricating oil will accumulate at the port under the action of gravity and press down on the Mylar plate 3. The Mylar plate 3 will then undergo axial elastic deformation towards the bottom surface of the stepped groove 12 under the pressure of the lubricating oil's own weight. This deformation will cause the wall of its central hole to fit more tightly against the outer surface of the rotating shaft 22, thereby significantly increasing the contact pressure and achieving adaptive sealing: the more lubricating oil accumulates and the greater the self-weight force generated, the greater the deformation of the Mylar plate 3, and the stronger the sealing pressure will be, effectively preventing the oil from seeping out along the surface of the rotating shaft 22.

[0034] Reference Figure 2 and Figure 4 Furthermore, based on the sealing structure of the Mylar sheet 3, this oil-leakage prevention structure also includes a second seal. A mounting sleeve 4 is fitted and fixed to the outer wall of the central column 1 of the fan frame via an interference fit, thereby enhancing the overall structural stability. A sealing plate 41 is integrally formed at the bottom end of the mounting sleeve 4, which precisely seals the port of the circular mounting groove 11. A through hole is provided on the sealing plate 41 for the rotating shaft 22 to pass through. An O-ring 5 is placed between the inner wall of the through hole and the outer wall of the rotating shaft 22, forming a dynamic seal between the rotating shaft 22 and the sealing plate 41 through the elastic compression deformation of the O-ring 5. Thus, the Mylar sheet 3 and the O-ring 5 together constitute a double sealing barrier. In addition, an air guide groove 42 is provided on the inner wall of the mounting sleeve 4, which can effectively balance the air pressure between the inside of the circular mounting groove 11 and the external environment, prevent the internal air pressure from fluctuating due to the heat generated by the fan operation or changes in ambient temperature, thereby preventing the air pressure difference from sucking or blowing the lubricating oil out from the sealing gap, and also preventing the air pressure fluctuation from interfering with the normal elastic deformation state of the Mylar sheet 3.

[0035] Reference Figure 2 and Figure 3 Furthermore, to optimize lubrication, several oil guide grooves 211 are evenly arranged on the outer wall of the bearing 21 of the rotating body 2. These oil guide grooves 211 are evenly arranged around the central axis of the bearing 21, and each oil guide groove 211 extends from one end face of the bearing 21 to the other end face along the axial direction of the bearing 21. The oil guide grooves 211 help the lubricating oil to be evenly distributed between the outer wall of the bearing and the inner wall of the circular mounting groove 11, forming a stable and continuous oil film, thereby reducing friction and wear. In the overall fan assembly structure, the end of the fan frame center column 1 away from the circular mounting groove 11 is connected to the fan frame 6. The fan frame 6 includes a frame body 61 and a connecting bracket 62 disposed on one end face of the frame body 61. The fan frame center column 1 is located at the center position inside the frame body 61 and is fixedly connected to the frame body 61 through the connecting bracket 62. The end of the rotating shaft 22 extending out of the circular mounting groove 11 is connected to the fan blade structure 7. The fan blade structure 7 includes a hub 71 and several blades 72 disposed on the outer wall of the hub 71, all blades 72 being evenly arranged around the center of the hub 71. A recessed groove is formed at the center of the hub 71, and the rotating shaft 22 is fixedly connected to the bottom center of this groove. After assembly, the central column 1 of the fan frame is precisely located inside this groove. Simultaneously, an inner stator 8 is fixedly disposed on the outer wall of the mounting sleeve 4, and a circuit board 9 is connected to the inner stator 8, which is fixedly mounted on the fan frame 6. Correspondingly, a rotor 100, positioned opposite and matching the inner stator 8, is connected to the inner wall of the groove in the fan blade structure 7. Thus, when the circuit board 9 controls the inner stator 8 to generate an alternating magnetic field, the rotor 100 drives the fan blade structure 7 and the rotating shaft 22 to rotate together.

[0036] Reference Figure 2 and Figure 3 Furthermore, to prevent the rotating shaft 22 from axially shifting or dislodging from the rotating body 2, a semi-circular connector 221 is provided at the end of the rotating shaft 22 away from the port of the circular mounting groove 11. Simultaneously, a limiting groove 13 is provided at the bottom of the circular mounting groove 11 of the fan frame center column 1, and the semi-circular connector 221 passes through this limiting groove 13. A limiting piece 14 is fixedly connected to the fan frame center column 1 at the opening of the limiting groove 13, and this limiting piece 14 has a through hole. The diameter of this through hole is configured to be larger than the diameter of the rotating shaft 22 but smaller than the diameter of the semi-circular connector 221. Therefore, when the rotating shaft 22 rotates, the limiting piece 14 does not obstruct the free rotation of the rotating shaft 22 body, but when the rotating shaft 22 has an axial tendency, the semi-circular connector 221 will be blocked by the limiting piece 14, thereby reliably limiting the maximum axial displacement of the rotating shaft 22 and ensuring that the rotating shaft 22 always operates stably within the rotating body 2. The limiting structure, together with the Mylar plate 3 and O-ring 5 at the port, ensures that the bottom limiting structure prevents the shaft 22 from moving harmfully, and the double sealing structure at the top ensures that the lubricating oil will not leak, thereby significantly improving the safety and reliability of the fan under inverted installation or vibration conditions.

[0037] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An oil-impregnated bearing fan oil leakage prevention structure characterized by comprising: The device includes a fan frame center column, with a circular mounting groove recessed on the end face of the center column. A rotating body is rotatably mounted within the circular mounting groove. The rotating body includes a bearing that matches the circular mounting groove and a rotating shaft that passes through the center of the bearing. The bearing is in transition fit with the circular mounting groove. One end of the rotating shaft protrudes from the port of the circular mounting groove. The center column has a stepped groove on the inner wall of the port of the circular mounting groove. A circular Mylar sheet is embedded in the stepped groove. The Mylar sheet is an elastic thin sheet structure. The Mylar sheet can elastically deform along the axial direction within the stepped groove. The Mylar sheet has a central hole. The rotating shaft passes through the central hole and is in transition fit with the central hole. A mounting sleeve is interference-fitted onto the outer wall of the center column. A sealing plate is provided at the bottom end of the mounting sleeve. The sealing plate closes the port of the circular mounting groove and has a through hole for the rotating shaft to pass through. An O-ring is provided between the inner wall of the through hole and the outer wall of the rotating shaft.

2. The oil leakage prevention structure for oil bearing fan according to claim 1, characterized in that: The depth of the stepped groove is greater than the thickness of the Mylar sheet, and there is an axial gap between the bottom surface of the stepped groove and the Mylar sheet, the size of which is 0.05mm to 0.2mm.

3. The oil-escape-preventing structure for oil-impregnated bearing fan according to any one of claims 1 or 2, characterized in that: The Mylar sheet is made of polyester film, polyimide film, or polytetrafluoroethylene film.

4. The oil-escape-preventing structure for an oil-impregnated bearing fan according to claim 1, characterized by: The inner wall of the mounting sleeve is provided with an air guide groove that penetrates through it.

5. The oil leakage prevention structure for an oil-impregnated bearing fan according to claim 1, characterized in that: The outer wall of the bearing is evenly distributed with a plurality of oil guide grooves, which are evenly distributed around the center of the bearing. Each oil guide groove extends along the axial direction of the bearing, and both ends of the oil guide groove extend to the two end faces of the bearing.

6. The oil leakage prevention structure for an oil-impregnated bearing fan according to claim 1, characterized in that: The fan frame is connected to the end of the central column of the fan frame away from the circular mounting groove, and the fan blade structure is connected to the end of the rotating shaft that extends out of the circular mounting groove.

7. The oil leakage prevention structure for an oil-impregnated bearing fan according to claim 6, characterized in that: The outer wall of the mounting sleeve is provided with an inner stator, the inner stator is connected to a circuit board, the circuit board is fixed to the fan frame, and the fan blade structure is connected to a rotor that matches the inner stator.

8. The oil leakage prevention structure for an oil-impregnated bearing fan according to claim 7, characterized in that: The fan frame includes a frame body and a connecting frame disposed on one end face of the frame body. The central column of the fan frame is located inside the center of the frame body and is connected to the connecting frame. The fan blade structure includes a hub and a plurality of blades disposed on the outer wall of the hub. The plurality of blades are evenly arranged around the center of the hub. A receiving groove is recessed in the center of the hub. The rotating shaft is connected to the bottom center of the receiving groove of the hub. The central column of the fan frame is located in the receiving groove. The rotor is connected to the inner wall of the receiving groove and is aligned with the inner stator.

9. The oil leakage prevention structure for an oil-impregnated bearing fan according to claim 1, characterized in that: A semi-circular connector is provided at the end of the rotating shaft away from the circular mounting groove port. A limiting groove is provided at the bottom of the circular mounting groove of the fan frame center column. The semi-circular connector passes through the limiting groove. A limiting piece is fixedly connected to the fan frame center column at the opening of the limiting groove. The limiting piece is provided with a through hole. The diameter of the through hole is configured to be larger than the diameter of the rotating shaft and smaller than the diameter of the semi-circular connector.

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