Miniature disc type motor and miniature fan thereof

Abstract

The invention discloses a miniature disc type motor and a miniature fan thereof, the miniature disc type motor comprises a PCB stator assembly and a driving control circuit, the PCB stator assembly comprises a PCB and a stator coil arranged on the PCB, the stator coil is connected with the driving control circuit, and the driving control circuit is connected with the PCB. The structural layout of the stator coil and the rotor magnet adopts a two-phase four-slot six-pole, three-phase six-slot four-pole or three-phase six-slot eight-pole structural layout, and better slot-pole matching of the miniature disc type motor is adopted, so that unbalanced radial magnetic pulling force is reduced, the torque fluctuation of the motor is improved, the vibration noise of a product is reduced, the sound quality of the product is improved, and the service life of the product is prolonged. The protrusion ratio of the product can be reduced to below 4dB; the optimized three-phase six-slot quadrupole can improve the motor efficiency by about 5%, the optimized three-phase six-slot octupole can improve the motor efficiency by about 12%, the optimized two-phase four-slot six-pole structure can improve the motor efficiency by about 5%, in addition, the overall layout is reasonable, the winding space is effectively increased, miniaturization and flattening of the miniature fan are better facilitated, and the service life of the miniature fan is prolonged. The size is further reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of micro disc motors, and in particular to a micro disc motor and a micro fan thereof. Background Art

[0002] For micro fans, due to limited space, the current commercial micro fan motor solutions are mainly the following:

[0003] 1. Radial flux motor. Due to limited size and space, a 4-slot 4-pole radial motor solution is generally used - Solution 1.

[0004] 2. Axial flux motor, also called disc motor. Due to the limited size and space, the ironless motor structure is often used. For the slot-pole matching of the stator and rotor, a 4-slot 4-pole single-phase motor - Scheme 2, or a 3-slot 4-pole three-phase motor - Scheme 3, or a 4-slot 6-pole two-phase motor - Scheme 4 is often used.

[0005] For Solution 1, this driving mode is a typical square wave voltage drive, which has fundamental torque fluctuations, and it is very difficult to suppress this torque fluctuation.

[0006] For solution 2, this driving mode is still a typical square wave voltage drive. In addition to the principle of torque fluctuation, this driving mode also has the problem of difficulty in starting. To solve this problem, a pre-eccentric positioning solution is often used, that is, a high magnetic permeability material is used to attract the rotor to a position that is easy to start. However, the introduction of high magnetic permeability materials will lead to additional problems. The presence of high magnetic permeability materials will produce additional cogging effects, causing cogging torque pulsation, which will further worsen the torque fluctuation.

[0007] For solution 3, the motor with an odd number of slots (or an odd number of coils) in the stator naturally has unbalanced radial electromagnetic force, which will cause additional vibration and noise. The stator coil of the commercial 3-slot 4-pole motor adopts SMT structure, and the outer periphery of the stator coil includes block insulation material, which reduces the space of the coil and reduces the efficiency of the motor.

[0008] For Option 4, the commercial 4-slot 6-pole motor has a stator coil that uses an SMT structure. The stator coil is surrounded by block insulation material, which reduces the space for the coil and reduces the motor efficiency.

[0009] Therefore, none of the above solutions is the best one. Summary of the invention

[0010] In view of the above-mentioned deficiencies, the object of the present invention is to provide a micro-disc motor and a micro-fan thereof with reasonable structural design, which can effectively reduce vibration noise and improve sound quality.

[0011] To achieve the above purpose, the technical solution provided by the present invention is:

[0012] A micro disc motor comprises a PCB stator assembly, a rotor assembly and a drive control circuit, wherein the PCB stator assembly comprises a PCB board and a stator coil arranged on the PCB board, the structural layout of the stator coil and the rotor magnet in the rotor assembly adopts a two-phase four-slot six-pole, three-phase six-slot four-pole or three-phase six-slot eight-pole structure, and the stator coil is connected to the drive control circuit.

[0013] As a preferred solution of the present invention, the wire head and wire tail of the stator coil are on the same horizontal plane, and are led out from the top surface or bottom surface of the stator coil and correspondingly soldered to the wire head pad or wire tail pad of the PCB board.

[0014] As a preferred solution of the present invention, a plurality of stator coils are arranged on the PCB board in a replicating circular array.

[0015] As a preferred solution of the present invention, the wire head pad and the wire tail pad corresponding to each stator coil are arranged on the PCB board, and the diameter of the circular track of the pads surrounded by them is larger than the diameter of the circular coil track surrounded by the stator coil.

[0016] As a preferred solution of the present invention, the stator coil is wound with self-adhesive enameled wire. The conventional SMT structure is changed to a self-adhesive coil structure, and the coil can be used as a separate coil unit after forming, and no longer needs to be covered with insulating material, so as to make full use of the space inside the motor, increase the slot full rate of the coil, increase the number of turns of the motor, and thus improve the efficiency of the motor.

[0017] As a preferred solution of the present invention, two stator coils at opposite positions are connected in series to form one phase.

[0018] As a preferred solution of the present invention, the drive control circuit includes a drive chip and a DC voltage supply unit connected to the drive chip respectively, a filter input interface circuit, a voltage division debugging circuit, a DIR mode selection circuit, a MOD mode selection circuit, an FG output circuit and a PWM speed regulation circuit.

[0019] As a preferred solution of the present invention, the drive control circuit includes a drive chip one, a drive chip two, a DC voltage supply unit, a filter input interface circuit, a voltage divider debugging circuit, an FG speed output circuit and a PWM speed regulation circuit. The DC voltage supply unit and the filter input interface circuit are connected to the drive chip one and the drive chip two through the voltage divider debugging circuit, the FG speed output circuit is connected to the drive chip one, and the PWM speed regulation circuit is connected to the drive chip one and the drive chip two.

[0020] A micro fan adopts the micro disc motor mentioned above.

[0021] The beneficial effects of the present invention are as follows: the structural layout of the stator coil and the rotor magnet in the present invention reasonably adopts a two-phase four-slot six-pole, three-phase six-slot four-pole or three-phase six-slot eight-pole structural layout, and adopts the optimal slot-pole matching of the micro-disk motor to reduce the unbalanced radial magnetic pull, improve the torque fluctuation of the motor, and thus reduce the vibration noise of the product, improve the sound quality of the product, and the protrusion ratio of the product can be reduced to below 4dB; and cooperate with the driving mode of the drive control circuit to effectively further reduce the overall torque fluctuation and improve the sound quality. The optimized three-phase six-slot four-pole can improve the motor efficiency by about 5%, the optimized three-phase six-slot eight-pole can improve the motor efficiency by about 12%, and the optimized two-phase four-slot six-pole structure can improve the motor efficiency by about 5%. In addition, the overall structural layout is reasonable, which effectively increases the winding space, is more conducive to the miniaturization and flattening of the micro fan, and further reduces the size.

[0022] The present invention is further described below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the decomposition structure of Example 1 of the present invention.

[0024] Figure 2 It is a structural schematic diagram of the PCB stator assembly in Example 1 of the present invention.

[0025] Figure 3 It is a schematic diagram of the structure of the drive control circuit in Example 1 of the present invention.

[0026] Figure 4 It is a schematic diagram of the decomposition structure of Example 2 of the present invention.

[0027] Figure 5 It is a structural schematic diagram of the PCB stator assembly in Example 2 of the present invention.

[0028] Figure 6 It is a schematic diagram of the structure of the drive control circuit in Example 2 of the present invention.

[0029] Figure 7 This is the principle of synthesizing the waveform of the two-phase motor in Example 2 of the present invention.

[0030] Figure 8 It is a performance comparison chart of the micro fans in Example 1, Example 2 and the comparative example of the present invention.

[0031] Fig. 9 It is a 1 / 3 octave spectrum diagram of Example 1 of the present invention.

[0032] Fig.10It is the narrowband noise spectrum of Example 1 of the present invention.

[0033] Fig.11 is a characteristic loudness spectrogram of embodiment 1 of the present invention.

[0034] Fig.12 It is a characteristic highlight ratio spectrum diagram of Example 1 of the present invention.

[0035] Fig.13 It is the modulation spectrum-fluctuation spectrum diagram of Example 1 of the present invention.

[0036] Fig.14 It is the modulation spectrum-roughness spectrum diagram of Example 1 of the present invention.

[0037] Fig.15 This is the 1 / 3 octave spectrum of Example 2 of the present invention.

[0038] Fig.16 It is the narrowband noise spectrum of Example 2 of the present invention.

[0039] Fig.17 It is a characteristic loudness spectrogram of embodiment 2 of the present invention.

[0040] Fig.18 It is a characteristic highlight ratio spectrum diagram of Example 2 of the present invention.

[0041] Fig.19 It is the modulation spectrum-fluctuation spectrum diagram of Example 2 of the present invention.

[0042] Fig. 20 It is the modulation spectrum-roughness spectrum diagram of Example 2 of the present invention.

[0043] Fig.21 It is the pure noise ratio spectrum of Example 2 of the present invention.

[0044] Fig. 22 It is the noise value-time spectrum of Example 2 of the present invention.

[0045] Fig.23 It is a 1 / 3 octave spectrum diagram of the comparative example of the present invention.

[0046] Fig.24 It is the narrowband noise spectrum of the comparative example of the present invention.

[0047] Fig.25 It is a characteristic loudness spectrum of the comparative example of the present invention.

[0048] Fig.26 It is a characteristic highlight ratio spectrum of the comparative example of the present invention.

[0049] Fig. 27 It is the modulation spectrum-fluctuation spectrum diagram of the comparative example of the present invention.

[0050] Fig.28 It is the modulation spectrum-roughness spectrum diagram of the comparative example of the present invention.

[0051] Fig.29 It is a pure noise ratio spectrum of the comparative example of the present invention. DETAILED DESCRIPTION

[0052] Example 1, see Figures 1 to 3 The present embodiment provides a micro fan, which includes an upper cover 1, an impeller assembly 2, a base assembly 3, a PCB stator assembly 4 and a drive control circuit, wherein the PCB stator assembly 4 is fixedly arranged on the base assembly 3, the impeller assembly 2 is rotatably arranged on the base assembly 3 corresponding to the position of the PCB stator assembly 4, and the upper cover 1 covers the base assembly 3.

[0053] The impeller assembly 2 includes a fan blade, a motor housing, a rotor magnet and a shaft core, wherein the shaft core is arranged at the center of the motor housing, the rotor magnet is arranged on the inner wall of the motor housing, and the fan blade is sleeved on the motor housing. If the fan blade is removed, the impeller assembly 2 is transformed into a rotor assembly. The micro-disk motor PCB stator assembly 4 and the rotor assembly are combined to form a micro-disk motor.

[0054] The PCB stator assembly 4 includes a PCB board 41 and a stator coil 42 arranged on the PCB board 41. The structural layout of the stator coil 42 and the rotor magnet adopts three-phase six-slot four-pole or three-phase six-slot eight-pole to reduce unbalanced radial magnetic pull. The stator coil 42 is connected to the drive control circuit.

[0055] The base assembly 3 includes an outer frame and a back iron, and the outer frame is provided with a bearing in the middle tube, and the shaft core is arranged on the bearing. The back iron is arranged on the back of the outer frame corresponding to the position of the stator coil 42, and does not contact the PCB board 41. The outer frame does not need to have a through hole at the back iron installation position, and only a blind hole is required. The outer frame is provided with a positioning boss corresponding to the inner circle hole position of the stator coil 42, which improves the positioning accuracy of the coil and reduces the difficulty of assembling the coil.

[0056] The wire ends and wire tails of the stator coil 42 are on the same horizontal plane, and are led out from the top surface or bottom surface of the stator coil 42 and welded to the wire end pad or wire tail pad of the PCB board 41. A plurality of stator coils 42 are arranged on the PCB board 41 in a replicating circular array. The wire end pad and wire tail pad corresponding to each stator coil 42 are arranged on the PCB board 41, and the diameter of the circular track of the pads surrounded is larger than the diameter of the circular coil track surrounded by the stator coil 42. That is, the wire end pad and wire tail pad are located at the outer position of the stator coil 42, rather than between two adjacent stator coils 42, which effectively increases the winding space. The stator coil 42 is preferably wound with self-adhesive enameled wire. The conventional SMT structure is changed to a self-adhesive coil structure. After the coil is formed, it can be used as a separate coil unit without the need to be coated with insulating material, so as to make full use of the space inside the motor, increase the slot full rate of the coil, increase the number of turns of the motor, and thus improve the efficiency of the motor.

[0057] Two stator coils 42 at opposite positions are connected in series to form one phase. Specifically, the three-phase six-slot four-pole and three-phase six-slot eight-pole stator coils are six. The six slots refer to six stator coils, and four poles or eight poles are the poles of the rotor magnet. Figure 2 The three-phase six-slot layout diagram is shown below. Figure 3 The schematic diagram of the three-phase six-slot drive control circuit is shown in Figure 1. The specific wiring is that the stator coil U and the stator coil U' are connected in series as one phase, the stator coil V and the stator coil V' are connected in series as one phase, and the stator coil W and the stator coil W' are connected in series as one phase. Two coils of each phase are connected in series to form three-phase coils of U0, V0, and W0.

[0058] The drive control circuit includes a drive chip and a DC voltage supply unit, a filter input interface circuit, a voltage division debugging circuit, a DIR mode selection circuit, a MOD mode selection circuit, a FG output circuit and a PWM speed regulation circuit respectively connected to the drive chip. The DC voltage supply unit is used to provide a DC voltage input. The filter input interface circuit is used to filter out the high-order harmonic components in the output voltage of the DC voltage supply unit to reduce voltage fluctuations. The voltage division debugging circuit is used to be connected in series with the stator coil, and the voltage input on the stator coil is adjusted by voltage division to adjust the fan speed. The DIR mode selection circuit is used for forward and reverse control, that is, it is used to adjust the rotation direction of the fan from counterclockwise to clockwise, or from clockwise to counterclockwise. The MOD mode selection circuit is used to adjust the output type of the FG signal (speed pulse signal), such as FG output, 1 / 2FG output, etc. The FG speed output circuit is used to output the FG signal (speed pulse signal) to the outside world to confirm the fan speed. The PWM speed regulation circuit is used to receive an external PWM signal (pulse width control) input from the outside, reduce the equivalent value of the voltage on the coil, and control the fan speed. The drive chip has a built-in hardware drive control logic and a built-in three-phase electronic switch (also known as a three-phase inverter bridge). The inverter bridge receives the internal PWM signal (wave generation) issued by the drive control logic, and drives the three-phase inverter bridge to generate a three-phase AC voltage (inversion). The three-phase AC voltage generated by the inverter bridge is loaded onto the three-phase coil to generate a three-phase AC current that changes synchronously with the rotor magnetic field. The three-phase AC currents differ by 120° electrical angle from each other. The energized wire is subjected to force under the action of the magnetic field. According to the interaction between the action force and the reaction force, the coil generates a driving torque on the stator along the rotation direction, which drives the rotor system to operate normally. The PQ data and speed data of the micro fan in this embodiment are shown in Table 1.

[0059] Table 1

[0060]

[0061] Example 2, see Figures 4 to 6 The present embodiment provides a micro fan, which is basically the same as the structure of the first embodiment, except that the structural layout of the stator coil 42 and the rotor magnet adopts a two-phase four-slot six-pole structure, and two motors share a rotor structure. Each phase of the motor contains two stator coils 42, and the two stator coils 42 at opposite positions are connected in series and matched with the same rotor. The outer contour of the stator coil 42 is a runway shape. The four slots refer to the four stator coils, and the six poles are the number of poles of the rotor magnet. Figure 5 The layout diagram of two-phase four-slot six-pole, Figure 6It is a schematic diagram of a two-phase, four-slot, six-pole drive control circuit; the specific wiring is that stator coil 1 and stator coil 2 are connected in series as one phase, and stator coil 3 and stator coil 4 are connected in series as one phase. The drive control circuit includes a drive chip 1, a drive chip 2, a DC voltage supply unit, a filter input interface circuit, a voltage division debugging circuit, an FG speed output circuit and a PWM speed regulation circuit. The DC voltage supply unit and the filter input interface circuit are connected to the drive chip 1 and the drive chip 2 through the voltage division debugging circuit, the FG speed output circuit is connected to the drive chip 1, and the PWM speed regulation circuit is connected to the drive chip 1 and the drive chip 2. The DC voltage supply unit is used to provide a DC voltage input. The filter input interface circuit is used to filter out the high-order harmonic components in the output voltage of the DC voltage supply unit to reduce voltage fluctuations. The voltage division debugging circuit is used to be connected in series with the stator coil, and the voltage input on the voltage division adjustment coil is adjusted to adjust the fan speed. The FG output circuit is used to output an FG signal (speed pulse signal) to the outside world to confirm the fan speed. The PWM speed regulation circuit is used to receive an external PWM signal (pulse width control) input from the outside, reduce the equivalent value of the voltage on the coil, and control the fan speed. The driver chip 1 and the driver chip 2 have built-in hardware-based drive control logic and built-in single-phase electronic switches (also called H bridges, or single-phase inverter bridges). The inverter bridge receives the internal PWM signal (wave generation) sent by the drive control logic, and drives the single-phase inverter bridge to generate an AC voltage (inversion). After the AC voltage generated by the inverter bridge is loaded onto the corresponding coil, an alternating current that changes synchronously with the rotor magnetic field is generated. The energized wire is subjected to force under the action of the magnetic field. According to the interaction between the action force and the reaction force, the coil generates a driving torque along the rotation direction on the stator, which drives the rotor system to operate normally. The driver chip 1 and the driver chip 2 control a motor respectively, and the two motors share a rotor, so the two driver chips ultimately drive a four-slot six-pole motor. The torque fluctuation generated by each single-phase motor is large, because the single-phase motor will have a zero torque point, which is a principle and cannot be reduced. Therefore, the torque fluctuation of the single-phase motor is large. By cooperating with each other, the torques output by the two single-phase motors are staggered by 90° electrical angle, and the fluctuation value of the synthetic torque of the two-phase motor is greatly reduced. The overall performance improves the torque fluctuation of the four-slot six-pole motor. Figure 7 The principle diagram of the torque synthesis of the two-phase motor reduces the vibration noise of the product and improves the sound quality of the product. The PQ data and speed data of the micro fan in this embodiment are shown in Table 2.

[0062] Table 2

[0063]

[0064] Comparative Example: A four-slot six-pole micro fan provided in the comparative example includes the upper cover 1, outer frame and fan blades in Example 1 or 2, and the difference is that only the micro disc motor is different. Due to the poor performance of the motor, the vibration and noise performance are different. The PQ data and speed data of the micro fan in the comparative example are shown in Table 3.

[0065] Table 3

[0066]

[0067] According to the disclosure and teaching of the above specification, technicians in the field to which the present invention belongs can also change and modify the above implementation. Therefore, the present invention is not limited to the specific implementations disclosed and described above, and some modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for the convenience of explanation and do not constitute any limitation to the present invention. As described in the above embodiments of the present invention, other motor and fan structures obtained by using the same or similar structures are all within the protection scope of the present invention.

Claims

1. A micro disc motor, characterized in that: It includes a PCB stator assembly, a rotor assembly and a drive control circuit. The PCB stator assembly includes a PCB board and a stator coil arranged on the PCB board. The structural layout of the stator coil and the rotor magnet in the rotor assembly adopts a two-phase four-slot six-pole, three-phase six-slot four-pole or three-phase six-slot eight-pole structure. The stator coil is connected to the drive control circuit.

2. The micro disc motor according to claim 1, characterized in that: The wire head and wire tail of the stator coil are on the same horizontal plane, and are simultaneously led out from the top surface or the bottom surface of the stator coil and correspondingly soldered on the wire head pad or the wire tail pad of the PCB board.

3. The micro disc motor according to claim 2, characterized in that: A plurality of stator coils are arranged on the PCB board in a replicating circular array.

4. The micro disc motor according to claim 3, characterized in that: The wire head pad and the wire tail pad corresponding to each stator coil are arranged on the PCB board, and the diameter of the circular track of the pads surrounded by them is larger than the diameter of the circular coil track surrounded by the stator coil.

5. The micro disc motor according to claim 1, characterized in that: The stator coil is wound with self-adhesive enameled wire.

6. The micro disc motor according to any one of claims 1 to 5, characterized in that: Two stator coils at opposite positions are connected in series to form one phase.

7. The micro disc motor according to claim 1, characterized in that: The drive control circuit includes a drive chip and a DC voltage supply unit connected to the drive chip respectively, a filter input interface circuit, a voltage division debugging circuit, a DIR mode selection circuit, a MOD mode selection circuit, an FG output circuit and a PWM speed regulation circuit.

8. The micro disc motor according to claim 1, characterized in that: The drive control circuit includes a drive chip 1, a drive chip 2, a DC voltage supply unit, a filter input interface circuit, a voltage division debugging circuit, an FG speed output circuit and a PWM speed regulation circuit. The DC voltage supply unit and the filter input interface circuit are connected to the drive chip 1 and the drive chip 2 through the voltage division debugging circuit, the FG speed output circuit is connected to the drive chip 1, and the PWM speed regulation circuit is connected to the drive chip 1 and the drive chip 2.

9. A miniature fan, characterized in that: It comprises the micro disc motor as described in any one of claims 1-8.

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