Miniature two-phase claw pole type motor and fan thereof

Abstract

The utility model discloses a miniature two-phase claw pole type motor and a fan thereof, the motor comprises an outer frame, a rotor unit and a stator unit, the stator unit comprises two stator assemblage, the two stator assemblage are coaxially arranged on the outer frame in an overlapping mode and staggered by a certain mechanical angle along the circumferential direction, and the rotor unit is arranged on the outer frame. The stator assembly is a claw pole type motor stator. According to the utility model, the structural design is reasonable, the two stators are ingeniously assembled to form a two-phase motor, and the phase difference of the torque waveform is reasonably distributed, so that the torque ripple is effectively reduced, and the vibration and noise are reduced; and meanwhile, the stator assembly adopts a claw pole type motor stator structure, so that compared with an axial flux motor, the magnetic leakage phenomenon can be remarkably reduced, the electromagnetic interference to peripheral equipment is reduced, the overall structure is simple, the implementation is easy, the cost is low, and the wide popularization and application are facilitated.

Description

TECHNICAL FIELD

[0001] The utility model relates to fan technical field, concretely relates to a micro two-phase claw pole type motor and fan thereof. BACKGROUND

[0002] With the development of intelligent terminal such as notebook computer, tablet computer, mobile phone and other products tend to thin direction, the fan for terminal product heat dissipation also makes more and more thin, the sound quality requirement of micro fan is also more and more strict. How to further improve the sound quality of micro fan, the fan industry has been a great challenge.

[0003] Through research, the sound quality of micro fan is related to the vibration of motor in addition to the residual unbalance of rotor. From the source of vibration, the vibration source of motor is divided into torque fluctuation and axial force fluctuation. Torque fluctuation is the main reason of motor vibration and noise. The torque fluctuation and its suppression technology of motor has been one of the research hotspots of brushless DC motor. Therefore, it is of great significance to study the method of reducing or suppressing torque fluctuation.

[0004] For micro fan, due to limited space, the current motor scheme is limited, and the current commercial micro fan motor scheme mainly includes the following:

[0005] 1. Radial flux motor. Due to limited size, 4-slot 4-pole radial motor scheme is generally used - scheme 1.

[0006] 2. Axial flux motor, also known as disc motor. Due to limited size, coreless motor structure is often used, and 4-slot 4-pole single-phase motor - scheme 2, or 3-slot 4-pole three-phase motor - scheme 3, or 4-slot 6-pole two-phase motor - scheme 4 is often used in slot pole matching of stator and rotor.

[0007] For scheme 1, this driving mode is a typical square wave voltage driving, which has principle torque fluctuation, and it is difficult to suppress this torque fluctuation.

[0008] For scheme 2, this driving mode is still a typical square wave voltage driving, which has principle torque fluctuation, and it is difficult to start. To solve this problem, pre- eccentric positioning scheme is often used, that is, high permeability material is used to attract the position of rotor to the position easy to start. However, the introduction of high permeability material will cause additional problems. The existence of high permeability material will produce additional cogging effect, cause cogging torque pulsation, and further deteriorate torque fluctuation.

[0009] For scheme 3, the motor with odd slots (or odd coils) naturally exists unbalanced radial electromagnetic force, which will cause additional vibration and noise. Therefore, this scheme is still not the best scheme.

[0010] For scheme 4, the motor can be considered as two 2-slot 6-pole single-phase disc motors in parallel, and for each single-phase motor, due to space limitation, 2 coils are used to simulate the effect of 6 coils. In order to achieve the best torque ripple suppression effect and avoid causing unbalanced electromagnetic force, the two motors are staggered by 270 degrees of electrical angle. This scheme is the driving scheme of the commercial 4-slot 6-pole motor. In theory, this scheme has good torque ripple suppression effect, however, due to the unevenness of the magnetic field waveform, the torque ripple generated by replacing 6 coils with 2 coils is still relatively large, and the torque ripple suppression effect will be weakened to a certain extent after two-phase superposition.

[0011] In addition, for schemes 2, 3 and 4, there is a common shortcoming - magnetic leakage. Specifically, for the disc motor scheme, the magnet often uses sintered neodymium iron boron, which has a high magnetic energy product. In addition, the air gap magnetic flux during operation is mainly distributed along the axial direction (this feature is the origin of the name of the axial magnet motor), so in the case of a plastic frame for the fan outer frame, there is a relatively obvious magnetic leakage phenomenon, which may cause electromagnetic interference to the equipment using the fan.

[0012] Therefore, the above schemes are not the best schemes. Therefore, it is necessary to develop a micro two-phase claw pole motor and fan that meets the requirements of low torque ripple and low magnetic leakage. Content of the utility model

[0013] In view of the above shortcomings, the purpose of the utility model is to provide a micro two-phase claw pole motor with reasonable structure design, which meets the requirements of low torque ripple and low magnetic leakage.

[0014] In order to achieve the above purpose, the technical scheme provided by the utility model is:

[0015] A micro two-phase claw pole motor, which comprises an outer frame, a motor shell, a rotor unit and a stator unit, the stator unit comprises two stator assemblies, the two stator assemblies are coaxially stacked on the outer frame and are staggered by a certain mechanical angle along the circumferential position, the stator assembly is a claw pole motor stator, and the rotor unit is rotationally arranged on the outer frame and is matched with the two stator assemblies. Two stator assemblies are used to form a two-phase motor scheme, and the phase difference of the torque waveform is reasonably distributed to reduce the torque ripple; the stator assembly adopts a claw pole motor stator structure instead of an axial flux motor to reduce magnetic leakage.

[0016] As a preferred scheme of the utility model, the rotor unit is a rotor assembly, and the rotor assembly comprises a motor shell and an annular magnet arranged on the inner wall of the motor shell. The magnetic field waveform uniformity of the annular magnet is obviously improved relative to the magnetic field of the magnetic cake in the axial direction.

[0017] As a preferred scheme of the utility model, the two stator assemblies are claw pole motor stators with eight-slot eight-pole structures, and the two stator assemblies are staggered along the circumferential position by the following theoretical mechanical angles: 22.5°, 67.5°, 112.5° or 157.5°.

[0018] As a preferred scheme of the utility model, the two stator assemblies are claw pole motor stators with six-slot six-pole structures, and the two stator assemblies are staggered along the circumferential position by the following theoretical mechanical angles: 30°, 90° or 150°.

[0019] As a preferred scheme of the utility model, the two stator assemblies are claw pole motor stators with four-slot four-pole structures, and the two stator assemblies are staggered along the circumferential position by the following theoretical mechanical angles: 45° or 135°.

[0020] As a preferred scheme of the utility model, the surface of the outer frame has recesses for accommodating the electronic components. The thickness space of the outer frame can be fully utilized, the occupied space is reduced, the surface flatness is ensured, the smoothness of the flow channel is improved, and the noise of the fan is reduced.

[0021] As a preferred scheme of the utility model, the outer frame comprises a top plate, a bottom plate and a side wall arranged at the edge of the bottom plate, and the top plate is arranged on the side wall. The structure design is reasonable and easy to assemble and produce.

[0022] As a preferred scheme of the utility model, the bottom plate is provided with a circuit board, and electronic components are welded on the circuit board. The electronic components comprise two ICs and other related electronic components, and the staggered angle of the two ICs is any one of the theoretical mechanical angles by which the two stator assemblies are staggered along the circumferential position. The two ICs are integrated with Hall effect sensors, which can sense the position of the rotor magnet to control the timely commutation of the two stator assemblies, so as to ensure that the cooperation of the two stator assemblies reaches the best effect.

[0023] A micro fan comprises a fan blade and the micro two-phase claw pole motor, and the fan blade cover is arranged on the motor shell of the micro two-phase claw pole motor.

[0024] The utility model discloses a beneficial effect is: the utility model discloses reasonable structure design, ingenious adoption two stator group constitutes two phase motor scheme, through reasonable distribution phase difference of torque waveform, effectively reduce the torque fluctuation, reduce vibration and noise, and the stator group adopts claw pole type motor stator structure simultaneously, compared with axial flux motor, can significantly reduce the leakage phenomenon, reduce the electromagnetic interference to the periphery equipment.

[0025] The utility model is further explained below in combination with the drawings and the embodiments. DRAWINGS

[0026] Figure 1 It is the three-dimensional structure schematic diagram of the utility model.

[0027] Figure 2 It is the sectional structure schematic diagram of the utility model.

[0028] Figure 3 It is the exploded structure schematic diagram of the utility model.

[0029] Figure 4 It is the structure schematic diagram of the stator unit in the utility model.

[0030] Figure 5 It is the harmonic component diagram of the utility model.

[0031] Figure 6 It is the torque fluctuation diagram of the utility model.

[0032] Figure 7 It is the phase voltage waveform diagram of the application. DETAILED DESCRIPTION

[0033] Embodiment, see Figures 1 to 7 The micro fan provided by the embodiment comprises a fan blade 1 and a micro two-phase claw pole type motor, the micro two-phase claw pole type motor comprises an outer frame 2, a rotor unit 4 and a stator unit 5. The rotor unit is a rotor group, and the rotor group comprises a motor shell 3 and an annular magnet 4 arranged on the inner wall of the motor shell 3. The fan blade 1 is covered on the motor shell 3 of the micro two-phase claw pole type motor. The outer frame 2 comprises a top plate 21, a bottom plate 22 and a side wall 23 arranged at the edge of the bottom plate 22, and the top plate 21 is arranged on the side wall 23. A magnetic conducting middle tube 24 is arranged on the bottom plate 22, a bearing 26 is arranged in the magnetic conducting middle tube 24, and a shaft core 25 matched with the bearing 26 is arranged on the motor shell 3. The shaft core 25 is arranged in the bearing 26, so that the motor shell 3 is assembled on the magnetic conducting middle tube 24.

[0034] The stator unit 5 comprises two stator assemblies 51 coaxially and vertically stacked on the magnetically conductive tube 24, and the two stator assemblies 51 are staggered by a certain mechanical angle along the circumferential position, and the stator assembly 51 is a claw pole motor stator. The rotor unit is a rotor assembly, that is, the two stator assemblies 51 share a rotor assembly, and the annular magnet. The rotor assembly is preferably an annular magnet, which not only simplifies the structure, but also significantly improves the magnetic field waveform uniformity of the annular magnet relative to the magnetic field of the axial magnetic cake. Each stator assembly 51 comprises an upper claw pole 511, a coil 512 and a lower claw pole 513. The following is described by taking the two stator assemblies 51 staggered by a certain mechanical angle (less than 180°) along the circumferential position as an example, and the preferred mechanical angle is as follows:

[0035] Scheme one: the two stator assemblies 51 can be claw pole motor stators with eight-slot eight-pole structure, forming a two-phase motor. The two stator assemblies 51 are staggered by the following four theoretical mechanical angles (less than 180°) along the circumferential position: 22.5°, 67.5°, 112.5° or 157.5°. Considering the assembly error, the preferred scheme is 157.5°*(1±10%).

[0036] Scheme two: the two stator assemblies 51 are claw pole motor stators with six-slot six-pole structure, forming a two-phase motor. The two stator assemblies 51 are staggered by the following three theoretical mechanical angles (less than 180°) along the circumferential position: 30°, 90°, 150°, considering the assembly error, the preferred scheme is 90°*(1±10%).

[0037] Scheme three: the two stator assemblies 51 are claw pole motor stators with four-slot four-pole structure, forming a two-phase motor. The two stator assemblies 51 are staggered by the following two theoretical mechanical angles (less than 180°) along the circumferential position: 45°, 135° scheme, considering the assembly error, the preferred scheme is 135°*(1±10%).

[0038] The circuit board is provided on the bottom plate, and electronic components are welded on the circuit board. The two stator assemblies 51 are connected with the three-dimensional conductive circuit 6. The electronic components 7 include two ICs, capacitors and other related electronic components 7, and the staggered angle of the two ICs can be any one of the theoretical mechanical angles of the two stator assemblies 51 staggered along the circumferential position. The two ICs are integrated with Hall effect sensors, which can sense the position of the rotor magnet to control the phase switching of the two stator assemblies in time, so as to ensure that the cooperation of the two stator assemblies reaches the best effect.

[0039] In summary, the utility model has the following advantages:

[0040] 1. Reduced torque fluctuation. First, a clever two-phase motor design using two stators is employed. Taking design two as an example, such as... Figure 7 As shown, the phase difference between the two motors is clearly demonstrated, indicating that the two motors work alternately. By rationally distributing the phase difference of the torque waveform between the two stator assemblies 51, the torque fluctuation is reduced by more than 80%. This effectively reduces torque fluctuation, vibration, and noise. Secondly, each stator assembly 51 of this motor can independently constitute a complete motor, and the number of stator poles is the same as the number of rotor poles, thus effectively improving the torque waveform caused by magnetic field inhomogeneity. Compared with conventional designs, the higher harmonic components of the new design are reduced by approximately 76%.

[0041] 2. Reduced magnetic leakage. Because the stator assembly 51 adopts a claw-pole motor stator structure, its air gap magnetic circuit is similar to that of a conventional radial motor, resulting in very weak magnetic leakage, which can be essentially ignored. Furthermore, the rotor assembly uses a ring magnet, whose magnetic field waveform uniformity is significantly improved compared to the magnetic field of an axial magnetic disc.

[0042] 3. By adopting a claw pole motor, the number of coils in this motor is effectively reduced, thereby reducing manufacturing costs.

[0043] Based on the disclosure and teachings of the above specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, this utility model is not limited to the specific embodiments disclosed and described above, and some modifications and changes to this utility model should also fall within the protection scope of the claims of this utility model. Furthermore, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation on this utility model. As described in the above embodiments of this utility model, other motor and fan structures obtained using the same or similar structures are all within the protection scope of this utility model.

Claims

1. A micro two-phase claw motor comprising an outer frame, a rotor unit and a stator unit, characterized by, The stator unit comprises two stator assemblies which are coaxially stacked on the outer frame and are staggered by a certain mechanical angle along the circumferential position, the stator assembly is a claw-pole motor stator, and the rotor unit is rotationally arranged on the outer frame and is matched with the two stator assemblies.

2. The micro two-phase claw-pole motor according to claim 1, characterized by: The rotor unit is a rotor assembly which comprises a motor shell and an annular magnet arranged on the inner wall of the motor shell.

3. The micro two-phase claw-pole motor according to claim 1, characterized by: The two stator assemblies are both claw-pole motor stators with eight-slot eight-pole structure, and the two stator assemblies are staggered by the following theoretical mechanical angles along the circumferential position: 22.5°, 67.5°, 112.5° or 157.5°.

4. The micro two-phase claw-pole motor according to claim 1, characterized by: The two stator assemblies are both claw-pole motor stators with six-slot six-pole structure, and the two stator assemblies are staggered by the following theoretical mechanical angles along the circumferential position: 30°, 90° or 150°.

5. The micro two-phase claw motor according to claim 1, characterized by: The two stator assemblies are both claw-pole motor stators with four-slot four-pole structure, and the two stator assemblies are staggered by the following theoretical mechanical angles along the circumferential position: 45° or 135°.

6. The micro two-phase claw motor according to any one of claims 3-5, characterized in that: The outer frame comprises a top plate, a bottom plate and a side wall arranged at the edge of the bottom plate, and the top plate is arranged on the side wall.

7. The micro two-phase claw motor according to claim 6, characterized by: The bottom plate is provided with a circuit board, and electronic components are welded on the circuit board.

8. The micro two-phase claw motor according to claim 7, characterized by: The electronic components comprise two ICs, and the staggered angle of the two ICs is any one of the theoretical mechanical angles by which the two stator assemblies are staggered along the circumferential position.

9. A micro fan characterized by: It comprises a fan blade and the micro two-phase claw-pole motor of any one of claims 1-8, and the fan blade is arranged on the rotor unit of the micro two-phase claw-pole motor.

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