Outer rotor axial flow fan supported at two ends of stator shaft

Abstract

The utility model relates to the technical field of fans, in particular to an outer rotor axial flow fan with two ends of a stator shaft supported, the two ends of the stator shaft of the fan can be firmly fixed on a front mesh enclosure and a rear mesh enclosure, the fan is provided with an outer rotor motor and at least two blades, and the blades are fixed on an outer rotor. The stator shaft extends out of the outer rotor in two directions and is supported and fixed by a front mesh enclosure and a rear mesh enclosure respectively; the front mesh enclosure and the rear mesh enclosure respectively comprise a fixing disc for supporting and fixing the stator shaft; the stator shaft is provided with a positioning step abutting against the inner end face of the fixing disc and a threaded section extending out of a mounting hole of the fixing disc, a fixing nut screwed on the threaded section abuts against the outer end face of the fixing disc, the fixing disc is a steel plate forming part, the mounting hole in the fixing disc is a round flaw hole formed through forming, and the threaded section of the stator shaft is a round flaw stud section. The chord plane of the thread section is an inclined plane with a high inner part and a low outer part; and when the fixing nut is screwed inwards to a fixed position, one part of an outer segmental part of the segmental hole is extruded into a segmental space of the segmental stud section in the fixing nut due to plastic deformation.

Description

Technical Field

[0001] This utility model relates to the field of fan technology, and in particular to an external rotor axial flow fan supported at both ends of the stator shaft. Background Technology

[0002] Household floor fans are a type of internal rotor axial flow fan. Their structure consists of an impeller mounted on the extended shaft of the motor, with the impeller protected by front and rear guards. The rear guard is fixed to the motor housing, and the front guard is fixed to the rear guard. The motor is an internal rotor motor. Cooling fans for computer CPUs are a type of external rotor axial flow fan, with the fan blades mounted on an external rotor. Both types of fan structures either have the impeller mounted on the extended shaft or the external rotor with the impeller mounted is rotated and supported by the extended stator shaft. Both rotating and stationary shafts are cantilevered support shafts.

[0003] The structure of the external rotor axial flow fan for computer CPUs is only suitable for making such small cooling fans. Only the structure of household fans can be used to make large-diameter axial flow fans. The impeller outer diameter of large-diameter axial flow fans can reach more than 1.5 meters. However, when using the structure of household fans to make large-diameter axial flow fans, considering the strength and rigidity requirements of the cantilevered shaft supporting the large-diameter impeller, the diameter of the motor shaft and the torque of the motor need to be larger. This results in a larger motor weight and volume, and the fixing bracket supporting the motor also needs to have sufficient strength and rigidity. Therefore, the existing large-diameter axial flow fans consume a lot of materials and have a low cost performance.

[0004] Designing a fan with an external rotor motor, and having the stator shaft extend at both ends and be supported and fixed on the front and rear guards respectively, can overcome the above-mentioned defects. However, this structure needs to overcome another technical problem, namely how to fix the stator shaft on the front and rear guards. A fixing plate is set in the center of the front and rear guards, and the stator shaft is fixedly installed in the mounting holes on the fixing plate. Due to the rotational vibration of the external rotor on the stator shaft and the repeated inertial impact of the forward and reverse torque loads when the large-diameter impeller starts and stops, when using the conventional method of connecting the circumferential anti-rotation key and the axial fixing nut, the repeated forward and reverse impacts and vibrations will cause the key to impact and wear against the keyway wall and / or the nut to loosen. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide an external rotor axial flow fan with stator shaft supported at both ends, wherein the stator shaft of the fan can be firmly fixed to the front and rear mesh covers.

[0006] The technical solution adopted by this utility model to solve its technical problem is: an external rotor axial flow fan supported at both ends of a stator shaft, having an external rotor motor and at least two blades, the external rotor motor having a stator shaft and an external rotor, at least two blades being circumferentially fixed on the external rotor, the axial flow fan having a front screen and a rear screen, the stator shaft of the external rotor motor extending bidirectionally from the inside of the external rotor and being supported and fixed at both ends by the front screen and the rear screen respectively, the front screen and the rear screen each including a fixing disc located at their respective center to support and fix both ends of the stator shaft;

[0007] The stator shaft has a positioning step that rests on the inner end face of the fixed plate and a threaded section extending from the mounting hole of the fixed plate. A fixing nut screwed onto the threaded section rests on the outer end face of the fixed plate. The fixed plate is a steel plate forming part. The mounting hole on the fixed plate is a formed segmental hole. The threaded section of the stator shaft is a segmental stud section. The chord surface of the threaded section is an inclined surface with an inner high and an outer low. When the fixing nut is screwed inward to the fixed position, a part of the segmental portion outside the segmental hole undergoes plastic deformation and is squeezed into the segmental space of the segmental stud section inside the fixing nut.

[0008] Specifically, the wire mesh of the front mesh cover is welded to a fixed plate, and the wire mesh of the rear mesh cover is welded to another fixed plate.

[0009] Specifically, the stator shaft has axial outlet holes for leading out the power lines.

[0010] Specifically, in order to increase the support strength, the fixing plate has a protrusion that extends into the fan, the mounting hole is located on the platform wall of the protrusion, and the fixing nut is located in the cavity on the back of the protrusion.

[0011] Specifically, the external rotor motor is a brushless motor.

[0012] The beneficial effects of this utility model are as follows: The axial flow fan provided by this utility model allows the stator shaft of the external rotor motor to extend in both directions, with blades set on the external rotor. The two ends of the stator shaft are supported by front and rear mesh covers respectively, which stabilizes the motor rotation. The two ends of the stator shaft are supported by steel plate forming parts. After the inclined chord surface of the stator shaft mates with the circular hole of the fixed plate, the nut squeezes the fixed plate mounting hole to deform and embed into the circular space between the nut and the threaded section, ultimately forming a firm fixation. There is no gap at the joint, and it will not wear due to forward and reverse inertial impact. This solves the problem of other structures having initial gaps that lead to gradual damage. This structure can also withstand multiple disassemblies and reassemblies of the stator shaft and the fixed plate. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is the front view of this utility model;

[0015] Figure 2 This is a partial sectional view of the present invention along the motor axis;

[0016] Figure 3 yes Figure 2 Enlarged view of point A;

[0017] Figure 4 This is a partially enlarged schematic diagram of the stator shaft end of this utility model, viewed along the axial direction.

[0018] Figure 5 This is the front view of the fixed disk in this utility model.

[0019] In the attached diagram: 1. Blade;

[0020] 2. Stator shaft; 2-1. Locating step; 2-2. Threaded section; 2-2-1. Chord surface; 2-2-2. Segmental space; 2-3. Lead-out hole;

[0021] 3. External rotor;

[0022] 4. Front grille;

[0023] 5. Rear mesh cover;

[0024] 6. Fixing plate; 6-1. Mounting hole; 6-2. Rounded part; 6-3. Protrusion; 6-4. Cavity; 7. Fixing nut;

[0025] 8. Power cord. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0027] As attached Figure 1An external rotor axial flow fan supported at both ends of the stator shaft, combined with an attached... Figure 2 The cross-sectional view shows an outer rotor motor and three blades 1. The outer rotor motor has a stator shaft 2 and an outer rotor 3. The three blades 1 are circumferentially fixed on the outer rotor 3. The axial flow fan has a front screen 4 and a rear screen 5. The stator shaft 2 of the outer rotor motor extends outward from the outer rotor 3 in both directions and is supported and fixed by the front screen 4 and the rear screen 5 respectively. The front screen 4 and the rear screen 5 each include a fixing plate 6 located at the center of each of them to support and fix both ends of the stator shaft 2.

[0028] like Figure 3 As shown, the stator shaft 2 has a positioning step 2-1 that rests on the inner end face of the fixed plate 6 and a threaded section 2-2 extending from the mounting hole 6-1 of the fixed plate 6. A fixing nut 7 screwed onto the threaded section 2-2 rests on the outer end face of the fixed plate 6. The fixed plate 6 is a steel plate forming part, and the mounting hole 6-1 on the fixed plate 6 is a formed chamfered hole. The chamfered shape of the mounting hole 6-1 is as follows: Figure 5 As shown, the threaded section 2-2 of the stator shaft 2 is a segmental stud section, and the chordal surface 2-2-1 of the threaded section 2-2 is an inclined surface with an inner higher surface and an outer lower surface. A portion of the segmental portion 6-2 outside the segmental hole undergoes plastic deformation and is squeezed into the segmental space 2-2-2 of the segmental stud section within the fixing nut 7 when the fixing nut 7 is tightened inward to the fixed position. Figure 3 and Figure 4 As shown, the aforementioned inside and outside refer to the inside and outside of the fan. Under relatively small external force, the geometry of the mounting hole 6-1 allows the outer end of the threaded section 2-2 to extend in, but does not allow the inner end of the threaded section 2-2 to extend in. The inner end of the threaded section 2-2 can only be squeezed into the mounting hole 6-1 when the fixing nut 7 is turned inward. The inner high and outer bottom inclined chord surface 2-2-1 plays a squeezing role. In addition to plastic deformation, the outer cleft part 6-2 of the cleft hole may also be accompanied by local tearing.

[0029] The support structures at both ends of the stator shaft 2 are the same; the attached diagram only shows the support structure at the front end.

[0030] The wire mesh of the front mesh cover 4 is welded to the fixed plate 6, and the wire mesh of the rear mesh cover 5 is welded to another fixed plate 6.

[0031] The stator shaft 2 has an axial outlet hole 2-3 for leading out the power line 8, and the power line 8 can also be led out from the rear end of the stator shaft 2.

[0032] Still see Figure 3 The fixed plate 6 has a protrusion 6-3 that extends into the fan. The mounting hole 6-1 is located on the platform wall of the protrusion 6-3. The fixing nut 7 is located in the cavity 6-4 on the back of the protrusion 6-3. In this way, the fixing nut 7 is in an internal state, which is both safe and aesthetically pleasing in structure.

[0033] The external rotor motor is a brushless motor.

[0034] The chord surface 2-2-1 on the threaded section 2-2 of this utility model can be one as shown in the figure or two circumferentially distributed, correspondingly making the circular notch 6-2 on the mounting hole 6-1 also two.

[0035] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A kind of outer rotor axial flow fan supported by stator shaft both ends, with outer rotor motor and at least two blades (1), the outer rotor motor has stator shaft (2) and outer rotor (3), at least two of the blade (1) circumferentially equal division is fixed on outer rotor (3), it is characterized by: The axial flow fan has front screen (4) and rear screen (5), the stator shaft (2) of the outer rotor motor is bidirectional from the inside of outer rotor (3) to the outside and is supported and fixed by front screen (4) and rear screen (5) at both ends respectively, front screen (4) and rear screen (5) include fixed disc (6) in the center of each respectively for supporting and fixing the both ends of stator shaft (2). The stator shaft (2) has the locating step (2-1) on the inner end surface of fixed disc (6) and the threaded section (2-2) that extends from the mounting hole (6-1) of fixed disc (6), the fixed nut (7) that is screwed on the threaded section (2-2) is on the outer end surface of fixed disc (6), the fixed disc (6) is steel plate forming piece, the mounting hole (6-1) on the fixed disc (6) is the circular defect hole formed, the threaded section (2-2) of the stator shaft (2) is circular defect stud section, the chord surface (2-2-1) of the threaded section (2-2) is the inclined surface of inner high outer bottom, a part of the outer circular defect part (6-2) of the circular defect hole is plastically deformed and extruded into the circular defect space (2-2-2) of circular defect stud section in fixed nut (7) when fixed nut (7) is screwed inward to fixed position.

2. The external-rotor, axial-flow fan of claim 1 wherein: The wire of front screen (4) is welded on fixed disc (6), and the wire of rear screen (5) is welded on another fixed disc (6).

3. The axial fan of claim 1 wherein: The stator shaft (2) has the lead-out hole (2-3) in the axial direction leading out power line (8).

4. The axial fan of claim 1 wherein: The fixed disc (6) has the protruding platform (6-3) that stretches to the fan, the mounting hole (6-1) is located on the platform wall of protruding platform (6-3), and the fixed nut (7) is located in the recessed cavity (6-4) on the back of protruding platform (6-3).

5. The axial fan of claim 1 wherein: The outer rotor motor is brushless motor.

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