A small high-speed DC fan with double-bearing structure

Abstract

The present invention discloses a small-sized high-speed DC fan with a double-bearing structure, comprising a wind tube assembly, wherein a rotor assembly (1) and a stator assembly (2) are arranged in the wind tube assembly, and an impeller (3) connected to the rotor assembly (1) is arranged at the air inlet end of the wind tube assembly; the wind tube assembly comprises a wind tube body (4) and a bracket body (5), wherein a first bearing chamber (41) is arranged at the air inlet end of the wind tube body (4), and the bracket body (5) is connected to an air outlet end of the wind tube body (4); the bracket body (5) comprises a ring body (51) of equal diameter to the wind tube body (4), a second bearing chamber (52) is arranged on the central axis of the ring body (51), and the second bearing chamber (52) and the ring body (51) are connected via a plurality of cross beams (53). The present invention has the advantages of high stability during operation, good product quality control, low defective rate, and long service life.

Description

Technical Field

[0001] The invention relates to a DC fan, in particular to a small high-speed DC fan with a double-bearing structure. Background Art

[0002] Small high-speed brushless DC motors are opening up the hair dryer market with an overwhelming momentum. Its many advantages such as high speed, low power, and large air volume also crush more than 95% of the previous hair dryer motors. Its ultra-high speed of up to 100,000RPM mainly relies on its rotor assembly, which specifically includes multiple parts such as the shaft, bearings, and magnetic steel. Conventionally, two bearings are used to support the rotor, with the impeller on one side of the bearing and the magnetic steel on the other side of the bearing. The distance between the two bearings is short, which provides poor support for the shaft and reduces the stability of the fan operation. At present, in the overall design of the fan, the bearing installation room is generally not designed separately for the two bearings. The bearings are bonded to the stator frame or the inner wall of the wind tube, and the bonding strength is required to be high.

[0003] Although this type of rotor assembly is commonly used in hair dryer motors, there are only a few domestic companies that can independently supply fan rotor assemblies. Most companies purchase rotor assemblies from outside, which results in excessively high costs for the rotor assemblies. Since purchased rotor assemblies do not need to be assembled by themselves, they are prone to defects during transportation or storage. The quality of the assemblies is also difficult to control, and the consistency of the products is relatively poor, which increases the failure rate of finished fans and greatly increases production costs.

[0004] It is difficult for small high-speed DC fans to have new innovations within the framework of existing rotor assemblies. At present, when the fan speed is as high as 100,000RPM or above, the conventional rotor assembly bearing support strength is poor, resulting in low stability when the fan is running at high speed. During operation, the housing is prone to vibration, resulting in numbness. In this high-speed operating environment, the service life of the rotor assembly is not high. In addition, the single structure of the rotor assembly will also limit the development of other aspects of the fan. The rotor assembly needs to be assembled on the central axis of the wind tube. Therefore, the shape of the rotor assembly can be said to determine the installation position of the stator assembly, the shape of the stator assembly, and the shape of the wind tube to a certain extent. This is also a major reason why small DC fans have been difficult to make breakthroughs in size since their development.

[0005] Therefore, existing small-scale high-speed DC fans have the problems of low fan operation stability, poor product quality control, high defective rate and short service life. Summary of the invention

[0006] The object of the present invention is to provide a small high-speed DC fan with a double-bearing structure, which has the advantages of high stability during operation, good product quality control, low defective rate and long service life.

[0007] The technical solution of the present invention is as follows: a small high-speed DC fan with a double-bearing structure includes a wind tube assembly, a rotor assembly and a stator assembly are arranged in the wind tube assembly, and an impeller connected to the rotor assembly is arranged at the air inlet end of the wind tube assembly; the wind tube assembly includes a wind tube body and a bracket body, a first bearing chamber is arranged at the air inlet end of the wind tube body, and the bracket body is connected to the air outlet end of the wind tube body; the bracket body includes a ring body with the same diameter as the wind tube body, a second bearing chamber is arranged on the central axis of the ring body, and the second bearing chamber and the ring body are connected via a plurality of cross beams.

[0008] In the aforementioned small high-speed DC fan with a double-bearing structure, the crossbeam connects the outer wall of the second bearing chamber and the inner wall of the ring body, a first lug is provided at the connection between the inner wall of the ring body and the crossbeam, and a through screw hole is provided on the first lug, and a second lug corresponding to the first lug is provided on the inner wall of the connecting end of the wind tube body and the bracket body, and a screw hole is provided on the second lug; the thickness of the ring body is 4.5-10.5mm.

[0009] In the aforementioned small high-speed DC fan with a double-bearing structure, the bracket body is coaxially connected to the wind tube body, and the connection between the two is a structure of a sunken groove. The end face of the bracket body is provided with an inner concave of the sunken groove, and the end face of the wind tube body is provided with an outer convex of the sunken groove; the first lug is flush with the inner end face of the inner concave, and the second lug is flush with the outer end face of the outer convex.

[0010] In the aforementioned small-scale high-speed DC fan with a double-bearing structure, the number of the crossbeams is three.

[0011] In the aforementioned small high-speed DC fan with a double-bearing structure, the air cylinder body includes a cylinder body, a cylindrical stator assembly installation chamber is provided in the cylinder body, and a plurality of annularly distributed axial guide vanes are provided between the outer wall of the stator assembly installation chamber and the inner wall of the cylinder body along the axial flow direction of the air; a plurality of slots are provided on the cylinder wall of the stator assembly installation chamber.

[0012] In the aforementioned small high-speed DC fan with a double-bearing structure, the stator assembly includes three groups of skeleton monomers arranged in a ring, each group of skeleton monomers is formed by plugging an upper skeleton and a lower skeleton, an iron core monomer is embedded between the upper skeleton and the lower skeleton, and the iron core monomer is provided with a convex ridge that can be embedded in the card slot.

[0013] In the aforementioned small-scale high-speed DC fan with a double-bearing structure, the stator assembly installation chamber wraps over 60% of the length of the core monomer in the axial direction.

[0014] In the aforementioned small high-speed DC fan with a double-bearing structure, a pin hole is provided on the end surface of the upper frame, a pin is provided in the pin hole, and the pin and the crossbeam are axially staggered in the wind tube assembly.

[0015] In the aforementioned small high-speed DC fan with a double-bearing structure, the rotor assembly includes a rotating shaft, on which a first bearing, a magnetic steel and a second bearing are arranged in sequence along the inlet direction of the fan. The first bearing is assembled in a first bearing chamber, and the second bearing is assembled in a second bearing chamber.

[0016] In the aforementioned small-scale high-speed DC fan with a double-bearing structure, the first bearing chamber protrudes outward, and the impeller hub wraps around the first bearing chamber.

[0017] Compared with the prior art, the present invention has made a new design for the outer shell of the fan, and a bracket body connected to the fan body is added on the basis of the conventional fan body, wherein a bearing installation chamber is provided on the air inlet end of the fan body and the bracket body (equivalent to the air outlet end of the fan body) for installing two bearings on the rotor assembly, that is, the distance between the two bearings on the rotor assembly is maximized, providing better support for the rotating shaft and improving the stability of the fan during operation. The two bearings on the rotor assembly both have special bearing chambers, which makes it easier to position the bearings. After installation, their positions are not easily changed greatly due to the use of the fan, and their service life is extended.

[0018] The specific shape of the bracket body of the present invention is a three-claw type, which improves the structural stability; the bracket body and the wind tube body are matched with a countersunk groove and locked with bolts, which can better ensure the concentricity of the two bearing chambers; the present invention also designs the shape of the part of the wind tube body that wraps the stator assembly, controls the concentricity and verticality in the cavity, wraps more than 60% of the height of the stator core, ensures the concentricity of the stator assembly and the rotor assembly, reduces the vibration of the fan operation, and has a longer service life.

[0019] In addition, the bearing chamber close to the impeller of the present invention protrudes toward the impeller, and a new design is made for the impeller hub to wrap the bearing chamber, effectively shortening the length of the fan. The magnetic steel of the stator assembly and the rotor assembly of the fan are placed closer to the air inlet end of the fan, which can effectively alleviate the unpleasant experience of numbness caused by vibration of the entire machine casing during the operation of the fan, and reduce the operating noise of the fan.

[0020] Since the outer shell of the fan of the present invention is a split structure of the wind tube body and the bracket body, and each of the two major structures has a bearing chamber, the bearings of the rotor assembly can be positioned and assembled more conveniently. Enterprises do not need to purchase more expensive pre-assembled rotor assemblies, but can purchase parts separately and implement step-by-step installation of the rotor assembly. First, the bearings are placed in the corresponding bearing chambers and bonded, and then the rotating shaft is installed, which reduces the total production cost. After the fan is fully self-assembled, it also helps to improve product quality control and reduce the defective rate.

[0021] In summary, the present invention has the advantages of high stability during operation, good product quality control, low defective rate and long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a cross-sectional view of the internal structure of the present invention;

[0023] Figure 2 It is a schematic diagram of the three-dimensional explosion structure of the present invention;

[0024] Figure 3 is a schematic diagram of the structure of the bracket body;

[0025] Figure 4 It is a structural diagram of the air duct body;

[0026] Figure 5 is a cross-sectional view of the internal structure of the bracket body;

[0027] Figure 6 It is a cross-sectional view of the internal structure of the air duct body;

[0028] Figure 7 is a schematic diagram of the structure of the rotor assembly;

[0029] Figure 8 is a schematic diagram of the structure of the stator assembly;

[0030] Fig. 9 It is a schematic diagram of the external structure of the present invention;

[0031] Fig.10 It is a schematic diagram of the installation state of PCBA on the present invention.

[0032] Figure numerals: 1-rotor assembly, 2-stator assembly, 3-impeller, 4-wind cylinder body, 5-bracket body, 11-rotating shaft, 12-first bearing, 13-magnetic steel, 14-second bearing, 21-upper frame, 22-lower frame, 23-core monomer, 24-pin, 41-first bearing chamber, 42-second lug, 43-cylinder body, 44-stator assembly installation chamber, 45-axial guide vane, 46-slot, 51-ring body, 52-second bearing chamber, 53-cross beam, 54-first lug, 231-convex ridge, 301-hub. DETAILED DESCRIPTION

[0033] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0034] Embodiment: A small high-speed DC fan with a double-bearing structure, the structure is as follows Figures 1 to 10As shown, it includes a duct assembly, in which a rotor assembly 1 and a stator assembly 2 are arranged, and an impeller 3 connected to the rotor assembly 1 is arranged at the air inlet end of the duct assembly; the duct assembly includes a duct body 4 and a bracket body 5, and the air inlet end of the duct body 4 is provided with a first bearing chamber 41, and the bracket body 5 is connected to the air outlet end of the duct body 4; the bracket body 5 includes a ring body 51 with the same diameter as the duct body 4, and a second bearing chamber 52 is arranged on the central axis of the ring body 51, and the second bearing chamber 52 and the ring body 51 are connected via a plurality of cross beams 53; the design of the two bearing chambers maximizes the distance between the two bearings on the rotor assembly 1, can provide better support for the rotating shaft 11, and improve the stability of the fan during operation, and the two bearings on the rotor assembly 1 both have special bearing chambers, which also makes it easier to position the bearings, and their positions after installation are not easily changed due to the use of the fan, so that the service life can be extended.

[0035] The crossbeam 53 connects the outer wall of the second bearing chamber 52 and the inner wall of the ring body 51, and a first lug 54 is provided at the connection between the inner wall of the ring body 51 and the crossbeam 53, and a through screw hole is provided on the first lug 54, and a second lug 42 corresponding to the first lug 54 is provided on the inner wall of the connecting end of the wind tube body 4 and the bracket body 5, and a screw hole is provided on the second lug 42; the bracket body 5 is coaxially connected to the wind tube body 4, and the connection between the two is a structure of countersunk matching, and the matching surfaces are CNC-processed to ensure the concentricity of the two bearing chambers to the greatest extent, the end face of the bracket body 5 is provided with an inner concave of the countersunk groove, and the end face of the wind tube body 4 is provided with an outer convex of the countersunk groove; the first lug 54 is flush with the inner end face of the inner concave, and the second lug 42 is flush with the outer end face of the outer convex, and the bracket body 5 and the wind tube body 4 are axially locked after being buckled, and axially locked with bolts, which can better ensure the concentricity of the two bearing chambers.

[0036] The thickness of the ring body 51 of the bracket body 5 can be slightly modified according to the core stack thickness of the stator assembly 2, which will not greatly affect the performance of the product and has strong compatibility. The thickness can be selected in the range of 4.5-10.5mm, and this value includes the value of the concave section of the groove on the bracket body 5, and the concave section of the groove is 0.5mm.

[0037] For different motor powers, it is only necessary to select the thickness of the ring body 51 of the bracket body 5 and the length of the locking bolt to match different core monomers 23 and magnetic steels, without redesigning or making a new wind tube body 4, saving design and manufacturing costs. In this embodiment, the length of the core monomer 23 is 12mm and the power is 120W; when the length of the core monomer 23 is 15mm, the maximum power of the fan can be increased to more than 160W. At this time, it is only necessary to select a bracket body 5 with a ring body 51 thickened by 3mm, that is, a smaller new mold is invested, to achieve a significant adjustment of the fan power without changing the structure of the wind tube body 4.

[0038] The support body 5 is made of aluminum alloy material. The present invention adopts 6 series aviation aluminum material to improve the strength of the structure and reduce the weight of the fan.

[0039] Preferably, there are three cross beams 53 , that is, the specific shape of the bracket body 5 is a three-claw type, which helps to improve the structural stability, avoids the position of the six pins 24 of the three-slot motor, and ensures the overall supporting strength of the second bearing chamber 52 by the cross beam 53 .

[0040] The air cylinder body 4 includes a cylinder body 43, in which a cylindrical stator assembly installation chamber 44 is provided. A plurality of annularly distributed axial guide vanes 45 are provided between the outer wall of the stator assembly installation chamber 44 and the inner wall of the cylinder body 43 along the axial flow direction of air; a plurality of slots 46 are provided on the cylinder wall of the stator assembly installation chamber 44.

[0041] The stator assembly 2 includes three groups of skeleton monomers arranged in a ring shape, each group of skeleton monomers is formed by plugging an upper skeleton 21 and a lower skeleton 22, an iron core monomer 23 is embedded between the upper skeleton 21 and the lower skeleton 22, and a convex ridge 231 that can be embedded in the slot 46 is provided on the iron core monomer 23, so that the concentricity and verticality of the cavity formed by the stator assembly 2 are relatively high.

[0042] The stator assembly installation chamber 44 covers more than 60% of the length of the core monomer 23 in the axial direction, thereby ensuring the concentricity of the stator assembly 2 and the rotor assembly 1, reducing the vibration of the fan during operation, and prolonging the service life.

[0043] The upper frame 21 is provided with a pin hole on its end surface, in which a pin 24 is provided. A heat shrink tube is sleeved outside the pin 24. The pin 24 and the crossbeam 53 are arranged axially offset in the air duct assembly, so that the PCBA can be connected to the bracket body 5 above it. Fig.10 As shown, it is convenient to assemble the fan and the whole machine.

[0044] The rotor assembly 1 includes a rotating shaft 11 , on which a first bearing 12 , a magnet 13 and a second bearing 14 are arranged in sequence along the inflow direction of the fan. The first bearing 12 is assembled in a first bearing chamber 41 , and the second bearing 14 is assembled in a second bearing chamber 52 .

[0045] The first bearing chamber 41 protrudes outward, and the hub 301 of the impeller 3 wraps around the first bearing chamber 41, thereby shortening the overall length of the fan.

[0046] The magnetic steel 13 of the stator assembly 2 and the rotor assembly 1 are placed closer to the air inlet end of the fan, that is, the head of the fan, which further shortens the overall length of the fan.

[0047] The bottom of the second bearing chamber 52 is padded with a corrugated gasket.

[0048] The inlet section of the axial guide vane 45 is an arc-shaped guide plate, and the outlet section is a flat guide plate. The shape design of the axial guide vane 45 is combined with the design of placing the magnetic steel 13 of the stator assembly 2 and the rotor assembly 1 closer to the air inlet end of the fan (that is, the change of the center of gravity of the fan), so that the airflow does not need to be turned through the air duct, and the output efficiency is greatly improved, and the fan has high aerodynamic efficiency.

[0049] During assembly of the present invention, since the wind duct body 4 and the bracket body 5 are split structures, and the two major structures each have a bearing chamber, during installation, the first bearing 12 in the rotor assembly 1 can be separately bonded to the first bearing chamber 41 at the air inlet end of the wind duct body 4, and the second bearing 14 can be separately bonded to the second bearing chamber 52 at the center of the bracket body 5. The bearings of the rotor assembly 1 can be positioned and assembled more conveniently, and the enterprise does not need to purchase a more expensive assembled rotor assembly 1. The parts can be purchased separately and the rotor assembly 1 can be installed step by step. After the rotor assembly 1 and the stator assembly 2 are assembled with the wind duct body 4, the bracket body 5 is buckled on the wind duct body 4, and the countersunk groove is used to achieve circumferential locking. Finally, the bracket body 5 is connected to the wind duct body 4 with bolts to achieve axial locking.

[0050] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

Claims

1. A small high-speed DC fan with a double-bearing structure, characterized in that: The invention comprises a wind tube assembly, wherein a rotor assembly (1) and a stator assembly (2) are arranged in the wind tube assembly, and an impeller (3) connected to the rotor assembly (1) is arranged at the air inlet end of the wind tube assembly; the wind tube assembly comprises a wind tube body (4) and a bracket body (5), and a first bearing chamber (41) is arranged at the air inlet end of the wind tube body (4), and the bracket body (5) is connected to an air outlet end of the wind tube body (4); the bracket body (5) comprises a ring body (51) having the same diameter as the wind tube body (4), and a second bearing chamber (52) is arranged on the central axis of the ring body (51), and the second bearing chamber (52) and the ring body (51) are connected via a plurality of cross beams (53); The air cylinder body (4) comprises a cylinder body (43), a cylindrical stator assembly installation chamber (44) is provided in the cylinder body (43), a plurality of annularly distributed axial guide vanes (45) are provided between the outer wall of the stator assembly installation chamber (44) and the inner wall of the cylinder body (43) along the axial flow direction of air; a plurality of slots (46) are provided on the cylinder wall of the stator assembly installation chamber (44); The stator assembly (2) comprises three groups of skeleton monomers arranged in a ring shape, each group of skeleton monomers being formed by plugging an upper skeleton (21) and a lower skeleton (22), an iron core monomer (23) being embedded between the upper skeleton (21) and the lower skeleton (22), and a convex ridge (231) being provided on the iron core monomer (23) that can be embedded in the clamping seam (46); The rotor assembly (1) comprises a rotating shaft (11), on which a first bearing (12), a magnetic steel (13) and a second bearing (14) are arranged in sequence along an inflow direction of the fan, wherein the first bearing (12) is mounted in a first bearing chamber (41), and the second bearing (14) is mounted in a second bearing chamber (52).

2. A small high-speed DC fan with a double-bearing structure according to claim 1, characterized in that: The cross beam (53) connects the outer wall of the second bearing chamber (52) and the inner wall of the ring body (51); a first lug (54) is provided at the connection between the inner wall of the ring body (51) and the cross beam (53); a through screw hole is provided on the first lug (54); a second lug (42) corresponding to the first lug (54) is provided on the inner wall of the connection end between the wind tube body (4) and the bracket body (5); and a screw hole is provided on the second lug (42); the thickness of the ring body (51) is 4.5-10.5 mm.

3. A small high-speed DC fan with a double-bearing structure according to claim 2, characterized in that: The support body (5) is coaxially connected to the air duct body (4), and the connection between the two is a structure of a sunken groove. The end surface of the support body (5) is provided with an inner concave of the sunken groove, and the end surface of the air duct body (4) is provided with an outer convex of the sunken groove; the first lug (54) is flush with the inner end surface of the inner concave, and the second lug (42) is flush with the outer end surface of the outer convex.

4. A small high-speed DC fan with a double-bearing structure according to claim 1, 2 or 3, characterized in that: The number of the cross beams (53) is three.

5. According to claim 1, a small-sized high-speed DC fan with a double-bearing structure is characterized in that: The stator assembly installation chamber (44) covers more than 60% of the axial length of the iron core monomer (23).

6. The small-sized high-speed DC fan with a double-bearing structure according to claim 1 is characterized in that: A pin hole is provided on the end surface of the upper frame (21), a pin (24) is provided in the pin hole, and the pin (24) and the crossbeam (53) are arranged in an axially displaced manner in the wind tube assembly.

7. The small-sized high-speed DC fan with a double-bearing structure according to claim 1 is characterized in that: The first bearing chamber (41) protrudes outward, and the hub (301) of the impeller (3) wraps around the first bearing chamber (41).

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