Axial flow fan of inner rotor hybrid bearing

Abstract

The invention discloses an axial flow fan of an inner rotor hybrid bearing, which comprises a shell, a motor arranged in the shell and an impeller driven by the motor, and the bearing of the motor comprises a radial bearing and an axial bearing. The radial bearing is a sleeve, a gap is formed between the sleeve and the rotor, the gap is communicated with the external space of the motor through an air channel, and air flow circulates between the external space and the gap under the rotation action of the impeller. The axial bearing comprises an outer magnetic ring in close fit with the stator and an inner magnetic ring in close fit with the rotor, and a gap between the inner magnetic ring and the outer magnetic ring is communicated with a gap between the sleeve and the rotor. The structure that the gas dynamic pressure bearing is used in the radial direction and the magnetic suspension bearing is used in the axial direction is adopted, the gas dynamic pressure bearing has the advantages of being free of friction, long in service life and the like, the rotating speed of the bearing fan can be greatly increased, and the purposes of increasing air volume and air pressure are achieved.

Description

Technical Field

[0001] The present invention relates to a heat dissipation device, and more particularly to an axial flow fan. Background Art

[0002] Most of the existing axial flow fans use ball bearings. When the ball bearings bear high speeds, they generate serious heat and have a limited lifespan, resulting in a short overall lifespan of the axial flow fan. Summary of the Invention

[0003] The technical problem to be solved by the present invention: The axial flow fan has a short lifespan due to the use of ball bearings.

[0004] To solve the above technical problem, the present invention provides the following technical solution: An axial flow fan with an inner rotor hybrid bearing, comprising a housing, a motor disposed in the housing, an impeller driven by the motor. The motor includes a stator and a rotor, and a bearing disposed between the stator and the rotor. The bearing includes a radial bearing and an axial bearing; the radial bearing is a sleeve, and there is a gap between the sleeve and the rotor. This gap communicates with the external space of the motor through an air passage. Under the rotation of the impeller, the air flow circulates between the external space and the gap.

[0005] When the rotor starts to rotate, an air film is established between the sleeve and the rotor, and the air film supports the rotor. At the same time, the rotor drives the impeller to accelerate, and the air flow flows along the driving direction of the impeller and enters the gap between the sleeve and the rotor. The air pressure in this gap gradually increases, which is conducive to the floating of the rotor and makes it non-contact with the sleeve. In this way, the rotor rotates in an air-floating state and has no friction with the sleeve (i.e., the radial bearing), which can not only extend the lifespan of the axial flow fan, but also provide conditions for the axial flow fan to increase its speed.

[0006] As an option, the sleeve is injection molded on the stator, specifically injection molded onto the tooth part of the stator, and the sleeve is made of a non-metallic material.

[0007] As an option, the sleeve can be made of a metal material to ensure a certain rigidity. The sleeve made of a metal material is closely fitted with the stator.

[0008] As an option, the axial bearing uses a magnetic levitation bearing. The non-contact feature between the moving part and the stationary part of the magnetic levitation bearing provides conditions for the floating and sinking of the rotor in the sleeve, and also provides conditions for the gap between the sleeve and the rotor to communicate with the external space.

[0009] The axial bearing includes an outer magnetic ring closely fitted with the stator and an inner magnetic ring closely fitted with the rotor. The outer magnetic ring is located outside the inner magnetic ring, and the gap between the outer magnetic ring and the inner magnetic ring communicates with the gap between the sleeve and the rotor, enabling the gap between the sleeve and the rotor to communicate with the external space.

[0010] The impeller includes a radial disc structure and an axial cylindrical structure, and blades provided on the axial cylindrical structure. The radial disc structure is fixedly connected to the rotor shaft. There is an axial gap between the end faces of the sleeve and the stator and the radial disc structure, and a radial gap between the outer wall of the stator and the axial cylindrical structure. The axial gap, the radial gap, and the gap between the outer magnetic ring and the inner magnetic ring form the air passage.

[0011] In the structure of the present invention where a gas dynamic pressure bearing is used radially and a magnetic levitation bearing is used axially, the gas dynamic pressure bearing has advantages such as no friction and long life, enabling the bearing fan to significantly increase the rotational speed and achieve the purpose of increasing the air volume and air pressure. Brief Description of the Drawings

[0012] The following further describes the present invention with reference to the drawings:

[0013] Figure 1 is a schematic diagram of an axial flow fan;

[0014] Figure 2 is Figure 1 a schematic diagram of observing the axial flow fan from the rear in

[0015] Figure 3 a sectional view of the axial flow fan.

[0016] Symbol Description in the Drawings:

[0017] 10. Housing;

[0018] 20. Motor; 21. Stator; 22. Rotor; 220. Rotor shaft; 221. Magnetic steel; 23. Sleeve; 24. Outer magnetic ring; 25. Inner magnetic ring;

[0019] 30. Impeller; 31. Radial disc structure; 32. Axial cylindrical structure; 33. Axial gap; 34. Radial gap;

[0020] 40. Tailstock;

[0021] 50. PCB circuit board. Detailed Embodiments

[0022] First Embodiment

[0023] Referring to Figures 1 to 3 , an axial flow fan with an inner rotor hybrid bearing includes a housing 10, a motor 20 disposed in the housing, and an impeller 30 driven by the motor. The motor includes a stator 21 and a rotor 22, and a bearing disposed between the stator and the rotor. The bearing includes a radial bearing and an axial bearing; the radial bearing is a sleeve 23, and there is a gap between the sleeve and the rotor. This gap communicates with the external space of the motor through an air passage. Under the rotation of the impeller, the air flow circulates between the external space and the gap.

[0024] The rotor 22 includes a rotor shaft 220 and a magnet 221 mounted on the rotor shaft.

[0025] The sleeve 23 can be injection-molded on the stator 21, specifically injection-molded onto the teeth of the stator 21. This sleeve is made of a non-metallic material. Alternatively, to ensure that the sleeve 23 has a certain rigidity, the sleeve 23 is made of a metal material and is closely fitted with the stator 21.

[0026] The axial bearing uses a magnetic levitation bearing and is provided at the tail of the motor 20. The tail of the motor is equipped with a tailstock 40. The tailstock is connected to the housing 10, and a PCB board 50 is mounted on the tailstock. Both the tailstock 40 and the PCB board 50 adopt a hollow structure, so that the gap inherent in the magnetic levitation bearing itself communicates with the external space.

[0027] The impeller 30 includes a radial disk-shaped structure 31 and an axial cylindrical structure 32, and blades provided on the axial cylindrical structure. The radial disk-shaped structure is fixedly connected to the rotor shaft 220. There is an axial gap 33 between the end faces of the sleeve 23 and the stator 21 and the radial disk-shaped structure. There is a radial gap 34 between the outer side wall of the stator and the axial cylindrical structure. The axial gap, the radial gap, and the gap inherent in the axial bearing itself constitute the air passage.

[0028] Second Embodiment

[0029] Reference Figure 3 , an axial flow fan with an inner rotor hybrid bearing, includes a housing 10, a motor 20 provided in the housing, an impeller 30 driven by the motor. The motor includes a stator 21 and a rotor 22, and a bearing provided between the stator and the rotor. The bearing includes a radial bearing and an axial bearing; the radial bearing is a sleeve 23, and there is a gap between the sleeve and the rotor. This gap communicates with the external space of the motor through an air passage. Under the rotation of the impeller, the air flow circulates between the external space and the gap.

[0030] The rotor 22 includes a rotor shaft 220 and a magnet 221 mounted on the rotor shaft.

[0031] The sleeve 23 can be injection-molded on the stator 21, specifically injection-molded onto the teeth of the stator 21. This sleeve is made of a non-metallic material. Alternatively, to ensure that the sleeve 23 has a certain rigidity, the sleeve 23 is made of a metal material and is closely fitted with the stator 21.

[0032] The axial bearing uses a magnetic levitation bearing and is provided at the tail of the motor 20. Specifically, the axial bearing includes an outer magnetic ring 24 closely fitted with the stator 21 and an inner magnetic ring 25 closely fitted with the rotor 22. The outer magnetic ring is located on the periphery of the inner magnetic ring, and the gap between the outer magnetic ring and the inner magnetic ring communicates with the gap between the sleeve 23 and the rotor 22.

[0033] The tail of the motor is equipped with a tailstock 40, the tailstock is connected to the housing 10, and a PCB circuit board 50 is installed on the tailstock. Both the tailstock 40 and the PCB circuit board 50 adopt a hollow structure, so that the gap between the outer magnetic ring 24 and the inner magnetic ring 25 is communicated with the external space.

[0034] The impeller 30 includes a radial disc-shaped structure 31 and an axial cylindrical structure 32, and blades arranged on the axial cylindrical structure. The radial disc-shaped structure is fixedly connected to the rotor shaft 220. There is an axial gap 33 between the end faces of the sleeve 23 and the stator 21 and the radial disc-shaped structure, and a radial gap 34 between the outer side wall of the stator and the axial cylindrical structure. The axial gap, the radial gap and the gap between the outer magnetic ring 24 and the inner magnetic ring 25 form the air passage.

[0035] The above content is only the preferred embodiment of the present invention. For those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. The content of this specification should not be construed as a limitation to the present invention.

Claims

1. An axial flow fan with an inner rotor hybrid bearing, comprising a housing (10), a motor (20) arranged in the housing, an impeller (30) driven by the motor, the motor comprising a stator (21) and a rotor (22), and a bearing arranged between the stator and the rotor, the bearing comprising a radial bearing and an axial bearing; characterized in that: The radial bearing is a sleeve (23). There is a gap between the sleeve and the rotor, and this gap is connected to the external space of the motor through an air passage. Under the rotation of the impeller, the air flow circulates between the external space and the said gap.

2. The axial flow fan with an inner rotor hybrid bearing according to claim 1, characterized in that: The said sleeve (23) is injection-molded on the stator (21).

3. The axial flow fan with an inner rotor hybrid bearing according to claim 1, characterized in that: The said sleeve (23) is made of a metallic material and is in close fit with the stator (21).

4. The axial flow fan with an inner rotor hybrid bearing according to claim 1, characterized in that: The axial bearing adopts a magnetic levitation bearing.

5. The axial flow fan with an inner rotor hybrid bearing according to claim 4, characterized in that: The axial bearing includes an outer magnetic ring (24) in close fit with the stator (21) and an inner magnetic ring (25) in close fit with the rotor (22). The outer magnetic ring is located on the periphery of the inner magnetic ring, and the gap between the outer magnetic ring and the inner magnetic ring is connected to the gap between the sleeve (23) and the rotor (22).

6. The axial flow fan with an inner rotor hybrid bearing according to claim 1, characterized in that: The said impeller (30) includes a radial disc-shaped structure (31) and an axial cylindrical structure (32), and blades arranged on the axial cylindrical structure. The radial disc-shaped structure is fixedly connected to the rotor shaft (220). There is an axial gap (33) between the end faces of the sleeve (23) and the stator (21) and the radial disc-shaped structure, and a radial gap (34) between the outer sidewall of the stator and the axial cylindrical structure. The axial gap, the radial gap and the gap of the axial bearing itself form the said air passage.

7. The axial flow fan with an inner rotor hybrid bearing as claimed in claim 5, wherein: The said impeller (30) includes a radial disc-shaped structure (31) and an axial cylindrical structure (32), and blades arranged on the axial cylindrical structure. The radial disc-shaped structure is fixedly connected to the rotor shaft (220). There is an axial gap (33) between the end faces of the sleeve (23) and the stator (21) and the radial disc-shaped structure, and a radial gap (34) between the outer sidewall of the stator and the axial cylindrical structure. The axial gap, the radial gap and the gap between the outer magnetic ring (24) and the inner magnetic ring (25) form the said air passage.

Images