A brushless DC outer rotor fan

Abstract

The present invention discloses a brushless DC external rotor fan, belonging to the technical field of fans, aiming to overcome the defect that the existing external rotor fans have relatively large noise. The fan includes a rotating part and a fixed part. The rotating part includes a wind wheel, an external rotor and a rotating shaft. The fixed part includes a volute and an inner stator. It is characterized in that an elastic bearing seat is fixedly arranged on the fixed part, a bearing is arranged on the elastic bearing seat, and the rotating shaft is rotatably connected to the fixed part through the bearing. By installing the bearing on the fixed part through the elastic bearing seat, resonance between the rotating part and the fixed part during rotation can be avoided, the operating noise of the fan can be reduced, and the service life of the fan can be prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of fans and relates to a brushless DC outer rotor fan. Background Art

[0002] The existing outer rotor fan includes an outer rotor, an inner stator and a volute. The outer rotor is fixedly connected to a rotating shaft. The rotating shaft is directly and rigidly connected to the inner stator and the volute through a bearing. The rotation of the outer rotor drives the wind wheel to rotate. During the rotation process, the rotating part formed by the outer rotor, the rotating shaft and the wind wheel and the fixed part formed by the inner stator and the volute are prone to resonance, generating large noise and affecting the service life. Summary of the invention

[0003] In view of the problems existing in the prior art, the present invention proposes a brushless DC outer rotor fan, aiming to overcome the defect of the existing outer rotor fan having high noise.

[0004] The present invention is achieved in that:

[0005] A brushless DC outer rotor fan comprises a rotating part and a fixed part, wherein the rotating part comprises a wind wheel, an outer rotor and a rotating shaft, and the fixed part comprises a volute and an inner stator, and is characterized in that an elastic bearing seat is fixedly arranged on the fixed part, a bearing is arranged on the elastic bearing seat, and the rotating shaft is rotatably connected to the fixed part through the bearing. The bearing is installed on the fixed part through the elastic bearing seat, so that resonance between the rotating part and the fixed part can be avoided when the rotating part rotates, the noise of the fan operation is reduced, and the service life of the fan is increased.

[0006] Preferably, the hardness of the elastic bearing seat is 40-70HA. If the hardness of the elastic bearing seat is too high, the vibration reduction effect is poor, and if the hardness of the elastic bearing is too low, the fixed part and the rotating part are prone to relative shaking.

[0007] Preferably, the bearing includes a ball bearing and an oil-containing bearing. The ball bearing is arranged corresponding to the inner stator, and the outer end of the rotating shaft is connected to the volute through the oil-containing bearing. The ball bearing has high strength and good supporting effect. The corresponding arrangement of the inner stator can support the inner stator, the outer rotor and the wind wheel, thereby improving the service life of the fan. The bearing at the outer end of the rotating shaft does not need a strong pressure-bearing capacity, and an oil-containing bearing is used, which is relatively low in cost. In this way, both the service life and the manufacturing cost are taken into account, and the overall cost performance of the fan is improved.

[0008] Preferably, the outer wall of the oil-containing bearing is spherical, which facilitates maintaining the concentricity between the rotating shaft and the oil-containing bearing, reduces the vibration of the fan during operation, and reduces the operating noise.

[0009] Preferably, the outer rotor includes an iron shell and a magnetic ring fastened to the inner wall of the iron shell. A knurling is provided at one end of the rotating shaft. The rotating shaft is fixedly connected to the iron shell through rotor plastic encapsulation at the knurled part. The wind wheel is integrally formed on the rotor plastic encapsulation. The knurling can prevent circumferential slipping between the rotating shaft and the rotor plastic encapsulation.

[0010] Preferably, a limiting hole is provided on the bottom wall of the iron shell, and a part of the rotor plastic encapsulation passes through the limiting hole. This enables the iron shell to better transfer torque to the rotor plastic encapsulation and improves the stability of the wind wheel rotation.

[0011] Preferably, a first installation groove is provided on the outer wall of the volute, and the oil-impregnated bearing is installed in the first installation groove. This facilitates the maintenance and replacement of the oil-impregnated bearing.

[0012] Preferably, the inner wall of the volute has a mounting post, the inner stator is sleeved on the mounting post, the mounting post has a second installation groove, and the ball bearing is installed on the second installation groove.

[0013] Preferably, there is a mounting convex ring on the inner wall of the volute, and a control board is fixedly arranged on the mounting convex ring. The mounting convex ring can strengthen the local structure of the volute and facilitate the fixing of the control board by screws.

[0014] Preferably, the mounting post includes a bottom post, a middle post, and a top post with gradually increasing outer diameters. The iron core of the inner stator is sleeved on the top post and abuts against the end face of the middle post, and the control board is sleeved on the bottom post. This makes the installation of the inner stator and the control board more hierarchical, non-interfering with each other, and improves the assembly efficiency.

[0015] For the brushless DC outer rotor fan provided by the present invention, the bearing is installed on the fixed part through an elastic bearing seat, which can prevent resonance between the rotating part and the fixed part during rotation, reduce the running noise of the fan, and improve the service life of the fan. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic structural diagram of the fan;

[0017] Figure 2 is a schematic cross-sectional structural diagram of the fan;

[0018] Figure 3 is Figure 2 an enlarged view of the partial A in

[0019] Figure 4 is a schematic structural diagram of the rotating part;

[0020] Figure 5 is a schematic cross-sectional structural diagram of the rotating part;

[0021] Figure 6It is a schematic diagram of the cross-sectional structure of the fixed part;

[0022] Figure 7 is a schematic diagram of the first angle structure of the base;

[0023] Figure 8 is a schematic diagram of the second angle structure of the base;

[0024] Figure 9 It is a schematic diagram of the structure of the iron shell;

[0025] Figure 10 It is a structural diagram of an oil-containing bearing.

[0026] Explanation of the accompanying drawings: 100, volute; 110, base; 111, first mounting groove; 112, mounting column; 113, second mounting groove; 114, mounting convex ring; 115, bottom column; 116, middle column; 117, top column; 120, cover; 200, outer rotor; 210, iron shell; 211, limit hole; 220, magnetic ring; 300, rotating shaft; 310, graphite nylon gasket; 320, retaining ring; 400, rotor plastic sealing; 410, wind wheel; 510, ball bearing; 520, oil-containing bearing; 530, elastic bearing seat; 600, control board; 700, inner stator. DETAILED DESCRIPTION

[0027] The following will further describe the specific implementation of the present invention in combination with the accompanying drawings to make the technical solution of the present invention easier to understand and grasp. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0028] This embodiment provides a brushless DC outer rotor fan 200, such as Figures 1-6 As shown, it includes a rotating part and a fixed part, the rotating part includes a wind wheel 410, an outer rotor 200 and a rotating shaft 300, the fixed part includes a volute 100 and an inner stator 700, an elastic bearing seat 530 is fixedly arranged on the fixed part, a bearing is arranged on the elastic bearing seat 530, and the rotating shaft 300 is rotatably connected to the fixed part through the bearing. The bearing is installed on the fixed part through the elastic bearing seat 530, so that resonance between the rotating part and the fixed part can be avoided when the rotating part rotates, the operating noise of the fan can be reduced, and the service life of the fan can be increased. The volute 100 includes a base 110 and a cover body 120, the bearing is installed on the base 110, after the rotating part is assembled on the base 110, the cover body 120 is fixed to the base 110 to protect the rotating part.

[0029] The hardness of the elastic bearing seat 530 is 40-70HA, such as 50HA, 55HA, 60HA. If the hardness of the elastic bearing seat 530 is too high, the vibration reduction effect is poor, and if the hardness of the elastic bearing is too low, the fixed part and the rotating part are prone to relative shaking.

[0030] As shown Figure 3 in the figure, the bearing includes a ball bearing 510 and an oil-impregnated bearing 520. The ball bearing 510 is arranged corresponding to the inner stator 700, and the outer end of the rotating shaft 300 is connected to the volute 100 through the oil-impregnated bearing 520. The ball bearing 510 has high strength and good supporting effect. Arranged corresponding to the inner stator 700, it can support the inner stator 700, the outer rotor 200 and the wind wheel 410, improving the service life of the fan; the bearing at the outer end of the rotating shaft 300 does not require strong pressure-bearing capacity, and the oil-impregnated bearing 520 is used, with lower cost. In this way, both the service life and the manufacturing cost are taken into account, and the overall cost performance of the fan is improved. In other alternative embodiments, both bearings can be ball bearings 510 or both can be oil-impregnated bearings 520.

[0031] As shown Figure 10 in the figure, the outer wall of the oil-impregnated bearing 520 is spherical. In this way, the oil-impregnated bearing 520 can adaptively adjust its direction on the corresponding elastic bearing seat 530, facilitating the maintenance of concentricity between the rotating shaft 300 and the oil-impregnated bearing 520, reducing the vibration during the operation of the fan and the operation noise.

[0032] As shown Figures 4-5 in the figure, the outer rotor 200 includes an iron shell 210 and a magnetic ring 220 fastened to the inner wall of the iron shell 210. One end of the rotating shaft 300 is provided with knurling, and the rotating shaft 300 is fixedly connected to the iron shell 210 through the rotor plastic seal 400 at the knurled part, and the wind wheel 410 is integrally formed on the rotor plastic seal 400. The knurling can prevent circumferential slipping between the rotating shaft 300 and the rotor plastic seal 400. The wind wheel 410 is integrally formed on the rotor plastic seal 400, with a firm structure, convenient processing, and no need for additional assembly process of the wind wheel 410.

[0033] As shown Figure 9 in the figure, a limiting hole 211 is provided on the bottom wall of the iron shell 210, and a part of the rotor plastic seal 400 passes through the limiting hole 211. During the injection molding process, the injection molding material will pass through the limiting hole 211, so that the iron shell 210 can better transmit the torque to the rotor plastic seal 400, improving the rotational stability of the wind wheel 410.

[0034] As shown Figures 6-8 in the figure, a first mounting groove 111 is provided on the outer wall of the volute 100, and the oil-impregnated bearing 520 is installed in the first mounting groove 111. This facilitates the maintenance and replacement of the oil-impregnated bearing 520. After the rotating shaft 300 passes through the oil-impregnated bearing 520, a graphite nylon washer 310 is sleeved, and a snap ring 320 is installed for limiting.

[0035] The inner wall of the base 110 of the volute 100 has mounting posts 112. The inner stator 700 is sleeved on the mounting posts 112. The mounting posts 112 have second mounting grooves 113, and the ball bearings 510 are mounted on the second mounting grooves 113. The inner wall of the volute 100 has a mounting convex ring 114, and the control board 600 is fixedly arranged on the mounting convex ring 114. The mounting convex ring 114 can strengthen the local structure of the volute 100, facilitating the control board 600 to be fixed by screws. The mounting posts 112 include a bottom post 115, a middle post 116, and a top post 117 with gradually increasing outer diameters. The iron core of the inner stator 700 is sleeved on the top post 117 and abuts against the end face of the middle post 116, and the control board 600 is sleeved on the bottom post 115. This makes the installation of the inner stator 700 and the control board 600 more hierarchical, without interfering with each other, and improves the assembly efficiency.

Claims

1. A brushless DC outer rotor fan, comprising a rotating part and a fixed part, wherein the rotating part includes a wind wheel (410), an outer rotor (200) and a rotating shaft (300), and the fixed part includes a volute (100) and an inner stator (700), characterized in that, An elastic bearing seat (530) is fixedly arranged on the fixed part. A bearing is arranged on the elastic bearing seat (530), and the rotating shaft (300) is rotatably connected to the fixed part through the bearing; The hardness of the elastic bearing seat (530) is 40 - 70 HA; The bearing includes a ball bearing (510) and an oil-impregnated bearing (520). The ball bearing (510) is arranged corresponding to the inner stator (700), and the outer end of the rotating shaft (300) is connected to the volute (100) through the oil-impregnated bearing (520); The outer wall of the oil-impregnated bearing (520) is spherical; a first installation groove (111) is arranged on the outer wall of the volute (100), and the oil-impregnated bearing (520) is installed in the first installation groove (111).

2. The brushless DC external rotor fan according to claim 1, wherein The outer rotor (200) includes an iron shell (210) and a magnetic ring (220) fastened to the inner wall of the iron shell (210). One end of the rotating shaft (300) is provided with knurling. The rotating shaft (300) is fixedly connected to the iron shell (210) through a rotor plastic seal (400) at the knurling part, and the wind wheel (410) is integrally formed on the rotor plastic seal (400).

3. The brushless DC outer rotor fan according to claim 2, characterized in that, A limiting hole (211) is arranged on the bottom wall of the iron shell (210), and a part of the rotor plastic seal (400) passes through the limiting hole (211).

4. A brushless DC external rotor fan according to claim 1, characterized in that, The inner wall of the volute (100) has an installation post (112). The inner stator (700) is sleeved on the installation post (112). A second installation groove (113) is arranged on the installation post (112), and the ball bearing (510) is installed on the second installation groove (113).

5. The brushless DC external rotor fan according to claim 4, characterized in that, An installation convex ring (114) is arranged on the inner wall of the volute (100), and a control board (600) is fixedly arranged on the installation convex ring (114).

6. The brushless DC outer rotor fan according to claim 5, wherein, The installation post (112) includes a bottom post (115), a middle post (116) and a top post (117) with gradually increasing outer diameters. The iron core of the inner stator (700) is sleeved on the top post (117) and abuts against the end face of the middle post (116), and the control board (600) is sleeved on the bottom post (115).

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