Portable fan

Abstract

The present application discloses a portable fan including an air duct part, a blower part, and a handheld part, in which the air duct part includes a main body, an air guide cavity is disposed in the main body, an air outlet and an air inlet are disposed at both ends of the air duct part, the air outlet and the air inlet are all communicated with the air guide cavity, a positioning boss is disposed in the main body, the blower part includes a rotating blade and a driving part drivingly connected to the rotating blade, the rotating blade is rotatably mounted in the air guide cavity and disposed toward the air outlet, the driving part includes a stator and a rotor sleeved outside the stator, the rotor is fixedly installed on the rotating blade and disposed coaxially with the rotating blade, and the stator is fixedly sleeved on the positioning boss.

Description

[Technical field]

[0001] The present application relates to the field of fan technology, and in particular to portable fans, driving circuits for portable fans, and handheld fans. [Background technology]

[0002] Fans, which are very commonly used home appliances in people's daily life, drive air flow to dissipate people's heat. Current portable fans are popular because they are lightweight and easy to carry, and portable fans need to shorten the overall height and size of the product as much as possible. However, more and more coils are installed in the motor stator skeleton used in traditional portable fans, and the internal space of portable fans is becoming narrower. Summary of the Invention

[0003] The main object of the present application is to provide a portable fan, the portable fan includes an air duct part, a blower part and a handheld part, in which the air duct part includes a main body, an air guide cavity is disposed in the main body, an air outlet and an air inlet are disposed at both ends of the air duct part, the air outlet and the air inlet are all communicated with the air guide cavity, a positioning boss is disposed in the main body, the blower part includes a rotating blade and a driving part drivingly connected to the rotating blade, the rotating blade is rotatably mounted in the air guide cavity and disposed toward the air outlet, the driving part includes a stator and a rotor sleeved outside the stator, the rotor is fixedly mounted on the rotating blade and disposed coaxially with the rotating blade, and the stator is fixedly sleeved on the positioning boss. [Brief description of the drawings]

[0004] In this application, the embodiments are described with reference to the accompanying drawings. The drawings in this application are only used to describe the embodiments and are for illustrative purposes only. Without departing from the principles of this application, those skilled in the art can easily make other embodiments by following the steps described in the following description. [Figure 1-1] FIG. 2 is a structural schematic diagram of a fan provided in an embodiment of the present application. [Figure 1-2] FIG. 2 is a structural schematic diagram of a fan provided in an embodiment of the present application with some parts removed; [Figure 1-3] FIG. 2 is a schematic diagram of the structure of the fan provided in the embodiment of the present application from another perspective. [Figure 1-4] FIG. 2 is a cross-sectional view of a fan provided in an embodiment of the present application. [Figure 1-5] FIG. 2 is a cross-sectional view of a fan from another perspective provided in an embodiment of the present application. [Figure 1-6] FIG. 2 is a cross-sectional view of a fan provided in an embodiment of the present application. [Figure 1-7] FIG. 2 is a cross-sectional view of a fan from another perspective provided in an embodiment of the present application. [Figure 2-1] FIG. 2 is a schematic diagram of a charging and power supply circuit of the portable fan provided in an embodiment of the present application. [Figure 2-2] FIG. 2 is a schematic diagram of a fan drive circuit of the portable fan provided in an embodiment of the present application. [Figure 2-3] FIG. 2 is a schematic diagram of a main control circuit of the portable fan provided in an embodiment of the present application. [Figure 3-1] FIG. 2 is a schematic circuit diagram of the main control chip of the main control circuit of the portable fan driving circuit provided in an embodiment of the present application; [Figure 3-2] FIG. 2 is a schematic configuration diagram of a three-phase driving circuit and a current detection circuit of the portable fan driving circuit provided in an embodiment of the present application. [Figure 3-3] FIG. 2 is a schematic configuration diagram of a back electromotive force detection circuit of a portable fan driving circuit provided in an embodiment of the present application. [Diagram 3-4]FIG. 2 is a schematic diagram of an interface circuit and a charging management circuit of the portable fan driving circuit provided in an embodiment of the present application. [Figure 3-5] FIG. 2 is a schematic configuration diagram of an auxiliary chip of the main control circuit of the portable fan driving circuit provided in an embodiment of the present application; [Diagram 3-6] 1 is a schematic circuit structure diagram of an indicator light branch and a button of a portable fan driving circuit provided in an embodiment of the present application; [Diagram 3-7] FIG. 2 is a schematic configuration diagram of a first speed control device of a portable fan driving circuit provided in an embodiment of the present application. [Diagram 3-8] FIG. 2 is a schematic configuration diagram of a second speed control device of a portable fan driving circuit provided in an embodiment of the present application. [Diagram 3-9] FIG. 2 is a schematic configuration diagram of a main control circuit of the portable fan driving circuit provided in an embodiment of the present application. [Figure 3-10] FIG. 2 is a schematic configuration diagram of a three-phase driving circuit and a current detection circuit of the portable fan driving circuit provided in an embodiment of the present application. [Figure 3-11] FIG. 2 is a schematic configuration diagram of a back electromotive force detection circuit of a portable fan driving circuit provided in an embodiment of the present application. [Figure 3-12] FIG. 2 is a schematic diagram of a transistor temperature detection circuit of the portable fan driving circuit provided in an embodiment of the present application. [Figure 3-13] FIG. 2 is a schematic diagram of a battery voltage detection circuit of the portable fan driving circuit provided in an embodiment of the present application. [Figure 3-14] FIG. 2 is a schematic diagram of a burn interface of the portable fan drive circuit provided in an embodiment of the present application. [Figure 3-15] 1 is a schematic diagram of the configuration of the main control chip of the main control circuit of the portable fan driving circuit provided in an embodiment of the present application; FIG. [Figure 3-16] FIG. 2 is a schematic diagram of a three-phase driving circuit and a battery voltage and current detection circuit of the portable fan driving circuit provided in an embodiment of the present application. [Figure 3-17]FIG. 2 is a schematic configuration diagram of three three-phase control chips of the main control circuit of the portable fan drive circuit provided in an embodiment of the present application. [Figure 3-18] FIG. 2 is a schematic configuration diagram of a signal amplification circuit of a portable fan driving circuit provided in an embodiment of the present application. [Figure 3-19] FIG. 2 is a schematic configuration diagram of a transistor temperature detection circuit of a portable fan driving circuit provided in an embodiment of the present application. [Figure 3-20] FIG. 2 is a schematic configuration diagram of a lamp control circuit of a portable fan driving circuit provided in an embodiment of the present application; [Figure 3-21] FIG. 2 is a schematic configuration diagram of a Hall detection circuit of a portable fan driving circuit provided in an embodiment of the present application. [Figure 3-22] FIG. 2 is a schematic diagram of a switching control circuit of a portable fan driving circuit provided in an embodiment of the present application. [Figure 3-23] FIG. 2 is a schematic diagram of a direct current (DC) conversion circuit of the portable fan driving circuit provided in an embodiment of the present application. [Figure 3-24] FIG. 2 is a schematic block structural diagram of a portable fan provided in an embodiment of the present application. [Figure 4-1] FIG. 1 is a schematic configuration diagram of a handheld fan provided in an embodiment of the present application. [Figure 4-2] FIG. 2 is a schematic configuration diagram of a mounting bracket provided on the handheld fan provided in an embodiment of the present application. [Figure 4-3] FIG. 2 is a schematic configuration diagram of a handheld part of the handheld fan provided in an embodiment of the present application. [Figure 4-4] FIG. 2 is a schematic configuration diagram of a wiring opening provided in the handheld fan provided in an embodiment of the present application. [Figure 4-5] FIG. 1 is a schematic configuration diagram of a wiring groove of a handheld fan provided in an embodiment of the present application. [Figure 4-6] FIG. 2 is a schematic configuration diagram of a wiring groove of the handheld fan provided in an embodiment of the present application. [Figure 4-7]FIG. 2 is a structural schematic diagram of a range knob assembly and a protection switch button assembly in the handheld fan provided in an embodiment of the present application. [Figure 4-8] FIG. 2 is a schematic configuration diagram of an inner shell and an outer shell of the handheld fan provided in an embodiment of the present application. [Figure 4-9] FIG. 2 is a schematic configuration diagram of an air inlet and an air outlet provided in a portable fan provided in an embodiment of the present application. [Figure 4-10] FIG. 4-9 is a partially enlarged schematic diagram of a portion A in FIG. [Figure 4-11] FIG. 2 is a schematic configuration diagram of a fan assembly provided in the handheld fan provided in an embodiment of the present application. [Figure 5-1] FIG. 1 is a perspective view of a portable fan provided in an embodiment of the present application. [Figure 5-2] FIG. 2 is a cross-sectional view of a portable fan provided in an embodiment of the present application. [Figure 5-3] FIG. 1-2 is an enlarged view of part A in FIG. [Figure 5-4] FIG. 2 is a cross-sectional view of the portable fan provided in an embodiment of the present application from another direction. [Figure 5-5] FIG. 2 is a cross-sectional view of a portable fan provided in an embodiment of the present application. [Figure 5-6] FIG. 2 is a cross-sectional view of a portable fan provided in an embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0005] Hereinafter, the technical solutions of the embodiments of the present application will be described clearly and completely with reference to the drawings of the embodiments of the present application. It is to be understood that the specific embodiments described herein are only used to describe the present application, and do not limit the present application. It should be noted that for the convenience of description, the drawings show only some, but not all, of the configurations related to the present application. Based on the embodiments of the present application, all other embodiments that a person skilled in the art can obtain without inventive work are all within the scope of protection of the present application.

[0006] In this application, terms such as "first", "second", etc. are used to distinguish between different objects, not to describe a particular order. Moreover, the terms "comprise", "have", and any variations thereof are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but optionally includes unlisted steps or units, or includes other steps or units inherent to such process, method, product, or device.

[0007] An "embodiment" referred to in this specification means that a particular feature, structure, or characteristic described in connection with that embodiment may be included in at least one embodiment of the present application. The appearance of this phrase in various places in this specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. A person skilled in the art can explicitly or implicitly understand that the embodiments described in this specification can be combined with other embodiments.

[0008] Example 1 is shown in Figs. 1-1 to 1-7.

[0009] 1-1 to 1-7, in order to solve the above-mentioned problems, according to one aspect of the present application, the embodiment of the present application provides a portable fan. The portable fan includes an air duct part 10, a blowing part 20, and a handheld part 30, the air duct part 10 includes a main body, an air guide cavity 13 is disposed inside the main body, an air outlet 121 and an air inlet 111 are provided at opposite ends of the air duct part 10, the air outlet 121 and the air inlet 111 are both communicated with the air guide cavity 13, and a positioning boss 122 is disposed on the main body. The blowing part 20 includes a rotating blade 21 and a driving part 22 drivably connected to the rotating blade 21, the rotating blade 21 is rotatably mounted in the air guide cavity 13 and disposed toward the air outlet 121. The driving unit 22 includes a stator 221 and a rotor 222 sleeved on the outside of the stator 221, the rotor 222 is fixedly attached to the rotating blade 21 and arranged coaxially with the rotating blade 21, and the stator 221 is fixedly sleeved on the positioning boss 122. The handheld unit 30 is connected to the air duct unit 10, and is provided with a mounting cavity 34 in which a power supply assembly 31 is installed, and the power supply assembly 31 is electrically connected to the driving unit 22. In the portable fan provided in this embodiment, the driving unit 22 which is drivably connected to the rotating blades 21 is composed of a stator 221 and a rotor 222 sleeved on the outside of the stator 221, the rotor 222 is fixedly installed on the rotating blades 21 and arranged coaxially with the rotating blades 21, and at the same time, the stator 221 is fixedly sleeved and attached to the positioning boss 122, so that the power generated by the driving unit 22 provided in this embodiment can be directly transmitted to the rotating blades 21 via the rotor 222, and there is no need to provide a transmission device between the driving unit 22 and the rotating blades 21, thereby effectively improving the transmission efficiency of the portable fan provided by this embodiment.

[0010] In one preferred embodiment, the power supply assembly 31 provided by this embodiment is a battery.

[0011] As shown in Figures 1 and 5, in one specific embodiment, the main body of this embodiment includes a first shell 11 and a second shell 12, the first shell 11 is connected to the second shell 12, and an air guide cavity 13 is formed between the first shell 11 and the second shell 12. An air inlet 111 is arranged in the first shell 11, an air outlet 121 is arranged in the second shell 12, and a positioning boss 122 is arranged in the second shell 12, and the positioning boss 122 extends along the extension direction of the air guide cavity 13.

[0012] In a specific embodiment, as shown in Figs. 4 to 7, in this embodiment, a fixing hole is provided in the rotating blade 21, and the axis of the fixing hole is aligned in the same line as the axis of the rotating blade 21. The blower unit 20 includes a rotating shaft 23, and a first end of the rotating shaft 23 is fixedly inserted into the fixing hole. A positioning hole 1221 is provided inside the positioning boss 122, and the axis of the positioning hole 1221 is aligned in the same line as the axis of the rotating shaft 23. A second end of the rotating shaft 23 is rotatably inserted into the positioning hole 1221.

[0013] As shown in FIGS. 4 to 7, in order to improve the service life of the portable fan provided by this embodiment, the blower unit 20 of this embodiment also includes a bearing unit 24, the outer ring of the bearing unit 24 is fixed in the positioning hole 1221, and the inner ring of the bearing unit 24 is sleeved on the second end of the rotating shaft 23. The bearing unit 24 provided by this embodiment is provided between the positioning hole 1221 and the rotating shaft 23, and the outer ring of the bearing unit 24 provided by this embodiment is fixed in the positioning hole 1221, and the inner ring of the bearing unit 24 is sleeved on the second end of the rotating shaft 23, thereby preventing direct friction from occurring between the positioning hole 1221 and the rotating shaft 23. This can efficiently improve the service life of the portable fan provided by this embodiment.

[0014] 4 and 5, in a specific embodiment, the bearing unit 24 provided by this embodiment includes a rolling bearing, and the blower unit 20 further includes a limiting member 25, which is attached to the second end of the rotating shaft 23, and the bearing unit 24 is located between the limiting member 25 and the first end of the rotating shaft 23. By providing the limiting member 25 at the second end of the rotating shaft 23, the radial movement of the rolling bearing can be effectively limited.

[0015] 4 and 5, in a specific embodiment, in order to facilitate the installation of the rolling bearing provided by this embodiment, the number of bearing parts 24 in this embodiment is multiple, and an inner flange 12211 is provided on the inner wall of the positioning hole 1221, and the inner flange 12211 is disposed between two adjacent bearing parts 24, so that the two adjacent bearing parts 24 are disposed at a distance from each other. Through the limiting member 25 disposed on the second end of the rotating shaft 23 provided by this embodiment, the inner ring of the rolling bearing provided by this embodiment can be effectively limited, and the inner flange 12211 disposed on the inner wall of the positioning hole 1221 can effectively limit the outer ring of the bearing, so that the rolling bearing provided by this embodiment can be effectively installed.

[0016] In a preferred embodiment, the bearing portion 24 provided by this embodiment is a ball bearing, and lubricant is disposed in the ball bearing provided in this embodiment.

[0017] In a preferred embodiment, the bearing portion 24 provided by this embodiment is a ceramic bearing, and lubricant is disposed in the ceramic bearing provided by this embodiment.

[0018] In a preferred embodiment, the bearing portion 24 provided by this embodiment is a magnetic bearing.

[0019] In a preferred embodiment, the blower section 20 provided by this embodiment further includes an elastic part, which is sleeved onto the rotating shaft 23, and both ends of the elastic part provided by this embodiment are abutted against the inner ring of the rolling bearing and the rotating blade 21, respectively. The elastic part provided by this embodiment can apply an elastic force to the inner ring of the rolling bearing in a direction away from the air inlet 111, and can preload the rolling bearing through the elastic part provided by this embodiment, thereby effectively extending the service life of the rolling bearing.

[0020] 6 and 7, in any embodiment, in order to improve the service life of the portable fan provided by this embodiment, the bearing part 24 in this embodiment includes a plain bearing, and the blower part 20 further includes two seal rings 26, both of which are fitted into the rotating shaft 23 and disposed on both sides of the plain bearing. By disposing the plain bearing provided by this embodiment between the rotating shaft 23 and the positioning hole 1221, and by fixedly connecting the inner ring of the plain bearing to the second end of the rotating shaft 23 and the outer ring to the fixing hole, the friction between the rotating shaft 23 and the positioning hole 1221 can be converted into friction between the inner ring and the outer ring of the plain bearing, and the friction between the rotating shaft 23 and the positioning hole 1221 can be avoided, and the service life of the portable fan provided by this embodiment can be extended.

[0021] As shown in Figures 4 to 7, in a specific embodiment, the handheld unit 30 in this embodiment includes a third shell 32 and a fourth shell 33, the third shell 32 is connected to the fourth shell 33, and an attachment cavity 34 is formed between the third shell 32 and the fourth shell 33.

[0022] As shown in Figures 4 to 7, in a specific embodiment, the first shell 11 in this embodiment includes a main body 112 and an air duct lining 113, the air duct lining 113 is arranged in the main body 112, an air duct 1131 is arranged inside the air duct lining 113, and an air guide cavity 13 is formed between the air duct lining 113 and the second shell 12.

[0023] Due to the low price of single-phase motors, most handheld small portable fans on the market today are driven by single-phase motors, but the speed of single-phase motors is slow, so they cannot provide strong wind power and the user experience is poor. If you want a handheld small portable fan to provide more wind power, you need to use a high-speed motor to drive it, but the high-speed motor occupies a larger volume and is prone to wear on the portable fan.

[0024] In order to solve the above problem, the driving unit 22 in this embodiment is a three-phase motor, and by setting the driving unit 22 as a three-phase motor, the rotation speed of the rotating blades 21 can be effectively increased, so that the portable fan provided in this embodiment can provide strong wind power and effectively improve the user experience. At the same time, since the rotation speed of the three-phase motor is high, in order to avoid rapid wear between the rotating shaft and the positioning hole due to high-speed rotation and to ensure the life of the portable fan provided in this embodiment, the portable fan provided in this embodiment provides a bearing part between the positioning hole and the rotating shaft, so that the friction between the positioning hole and the rotating shaft can be converted from sliding friction to rolling friction inside the bearing part, and the wear between the positioning hole and the rotating shaft can be avoided, and the service life of the portable fan provided in this embodiment can be effectively improved.

[0025] As shown in FIGS. 1 to 7, in a specific embodiment, the handheld unit 30 provided in this embodiment is provided with a charging port 35, and the charging port 35 is electrically connected to the power supply assembly 31. Since the handheld unit 30 provided in this embodiment is provided with the charging port 35 and the charging port 35 is electrically connected to the power supply assembly 31, the power supply assembly 31 provided in this embodiment can be electrically connected to an external power source through the charging port 35, and the battery life of the portable fan provided in this embodiment is guaranteed.

[0026] In a preferred embodiment, a discharge port is disposed on the handheld part provided in this embodiment, the discharge port provided in this embodiment is electrically connected to the power supply assembly, the discharge port provided in this embodiment can be electrically connected to an external electronic device, and the electrical energy of the power supply assembly can be transmitted to the external electronic device through the discharge port provided in this embodiment.

[0027] In a preferred embodiment, the air inlet provided in this embodiment is provided with a grid assembly, the grid assembly provided in this embodiment includes a first grid member and a second grid member, the first grid member provided in this embodiment is fixedly connected to the first shaft, and the second grid member provided in this embodiment is pivotally connected to the first grid member, the first grid member provided in this embodiment has a plurality of first openings, the second grid member provided in this embodiment has a plurality of second openings, and the plurality of first openings provided in this embodiment are installed in one-to-one correspondence with the plurality of second openings, the second grid member provided in this embodiment has a closed state in which the first openings are completely covered, and an open state in which the first openings overlap the second openings, and the second grid member can be switched between the closed state and the open state by rotating the second grid member, and the intake volume of the air inlet can be effectively adjusted through the grid assembly provided in this embodiment, which can effectively improve the user experience.

[0028] In a preferred embodiment, the air duct portion 10 and the handheld portion 30 provided in this embodiment are fixedly connected. Of course, in other embodiments, the air duct portion 10 and the handheld portion 30 provided in this embodiment may be pivotally connected to be relatively rotatable.

[0029] In a specific embodiment, the third shell 32 provided in this embodiment is integrally injection molded with the first shell 11 , and the fourth shell 33 is integrally injection molded with the second shell 12 .

[0030] In another embodiment, the third shell 32 provided in this embodiment is pivotally connected to the first shell 11, and the fourth shell 33 is pivotally connected to the second shell 12, and the pivot axes of the third shell 32 and the first shell 11 are coaxial with the pivot axes of the fourth shell 33 and the second shell 12.

[0031] In summary, the portable fan provided by this embodiment has at least the following beneficial technical effects: In the portable fan provided by this embodiment, the driving unit 22 drivingly connected to the rotating blades 21 is configured as a stator 221 and a rotor 222 sleeved on the outside of the stator 221, the rotor 222 is fixedly installed on the rotating blades 21 and arranged coaxially with the rotating blades 21, and at the same time, the stator 221 is fixedly sleeved on the positioning boss 122, so that the power generated by the driving unit 22 provided by this embodiment can be directly transmitted to the rotating blades 21 through the rotor 222, and there is no need to arrange a transmission device between the driving unit 22 and the rotating blades 21, and the transmission efficiency of the portable fan provided by this embodiment is effectively improved.

[0032] Example 2 is shown in Figs. 2-1 to 2-3.

[0033] As shown in FIGS. 2-1 to 2-3, the control circuit of the portable fan includes a charging power supply circuit 20, a fan driving circuit 30, a control switch Q2, and a main control circuit 50.

[0034] The charging power supply circuit 20 is used to electrically connect an external power source and the battery 14, thereby receiving an external voltage VCC, charging the battery 14, and outputting a supply voltage VO. The fan driving circuit 30 is electrically connected to the charging power supply circuit 20 and the fan assembly 12, and is used to drive the rotation of the fan assembly 12. The control end of the control switch Q2 is used to receive the external voltage VCC and is grounded, a first conductive end of the control switch Q2 is used to electrically connect the battery 14 to receive the output voltage of the battery 14, and a second conductive end of the control switch Q2 is used to electrically connect with the fan driving circuit 30, and the control switch Q2 is turned off when it receives the external voltage VCC, and turned on when it does not receive the external voltage VCC.

[0035] The main control circuit 50 is electrically connected to the charging power supply circuit 20, the fan drive circuit 30 and the control switch Q2.

[0036] In this embodiment, as shown in FIG. 2-1, the charging power supply circuit 20 includes a charging port 21 and a charging management chip 22, a power terminal 211 of the charging port 21 receives the external voltage VCC and is electrically connected to a charging input pin VIN of the charging management chip 22, the power terminal 211 of the charging port 21 is also connected to a negative electrode of a constant-voltage discharge tube D1, and a positive electrode of the constant-voltage discharge tube D1 is grounded, a switch pin SW of the charging management chip 22 is used to electrically connect to a positive electrode BAT+ of the battery 14 through a first inductor L1, a boost output pin VOUT of the charging management chip 22 is used to output a power supply voltage VO, and a boost input pin of the charging management chip 22 is connected to a node between the battery 14 and the first inductor L1 through a first connection resistor 201 on the one hand, and is grounded through a first grounding capacitor 202 on the other hand. Through the charge management chip 22, the constant voltage discharge tube D1 and the first inductor L1, the charging and discharging of the charging port and the battery can be effectively managed, and the power supply voltage required for other circuits can be output, with a simple structure, easy implementation, and high safety.

[0037] The key input terminal KEY of the charging management chip 22 is electrically connected to the main control circuit 50. The first LED driving pin LED1 of the charging management chip 22 is grounded through a first grounding resistor 203 and a second grounding resistor 204 in sequence, the second LED driving pin LED2 of the charging management chip 22 is connected to the positive pole of the battery 14 through a second connecting resistor 205, the first indicator pin LED1 of the main control circuit 50 is grounded by a first indicator branch 51, and the second LED driving pin LED2 of the charging management chip 22 is also grounded by a second indicator branch 23, and the first indicator branch 51 and the second indicator branch 23 each include a current limiting resistor R and an indicator LED connected in series. It can be seen that the key input terminal SW of the charging management chip 22 is electrically connected to the main control circuit 50, so that the main control circuit 50 can control the charging management chip 22 to ensure the reliability of the control circuit. Through the first indicator branch 51 and the second indicator branch 23, the charging and power supplying state of the charging and power supplying circuit 20 can be indicated, so as to improve the user's experience. The main control circuit 50 can be an MCU.

[0038] As shown in FIG. 2-2, the control end of the control switch Q2 is used to receive the external voltage VCC and to be grounded, the first conductive end of the control switch Q2 is used to electrically connect the battery 14 to receive the output voltage of the battery 14, and the second conductive end of the control switch Q2 is used to electrically connect the fan driving circuit 30, the control switch Q2 is turned off when the external voltage VCC is received, and turned on when the external voltage VCC is not received, at this time the fan driving circuit 30 is powered by the battery 14. By accessing the external voltage VCC through the control switch Q2, the external voltage VCC can directly supply power to the fan driving circuit 30, which can avoid the fan driving circuit 30 from using the output voltage of the battery 14, and can not only charge the battery 14 faster, but also avoid the problem caused by simultaneous charging and discharging that affects the service life of the battery 14.

[0039] As shown in Fig. 2-2, the control end of the control switch Q2 can be grounded through a third ground resistor 206, and is electrically connected to the second conductive end of the control switch Q2 and the fan driving circuit 30 through a first diode D2, and the second control switch is a PMOS (P-Metal-Oxide-Semiconductor) field effect transistor. As can be seen, the stability and security of the control circuit can be improved through the third ground resistor 206 and the first diode D2, and the control switch Q2 is a PMOS field effect transistor, which has the technical effects of low cost, simple structure and control.

[0040] As shown in FIG. 2-2 , the fan driving circuit 30 includes a second inductor L2, a third control switch Q3, a second diode D3 and a boost feedback branch 31, one end of the second inductor L2 is used for electrically connecting the charging power supply circuit 20 to receive the external voltage VCC or the output voltage MVCC of the battery 14, the other end of the second inductor L2 is connected to the fan assembly 12 through the second diode D3, a first conductive end of the third control switch Q3 is connected to a node between the second inductor L2 and the second diode D3, a second conductive end of the third control switch Q3 is grounded, and a control end of the third control switch Q3 is electrically connected to the second pulse-width control signal output end FPWM of the main control circuit 50, thereby receiving the second pulse-width control signal output from the main control circuit 50. One end of the boost phyto-back branch 31 is connected to a node between the second diode D3 and the fan assembly 12, and the other end of the boost phyto-back branch 31 is grounded. The boost phyto-back branch 31 includes a first voltage dividing resistor 311 and a second voltage dividing resistor 312 connected in series. A node between the first voltage dividing resistor 311 and the second voltage dividing resistor 312 is connected to a boost feedback terminal FAAD of the main control circuit 50 via the third voltage dividing resistor 313, and a node between the third voltage dividing resistor 313 and the main control circuit 50 is also grounded by a second grounding capacitor 314. It can be seen that the fan driving circuit 30 configured as above can charge and discharge the second inductor L2 by controlling the switch of the third control switch Q3, thereby increasing the voltage on the right side of the second inductor L2 to supply power to the fan assembly 12. The boost feedback branch 31 samples the boosted voltage and feeds it back to the main control circuit 50 so that the main control circuit 50 can adjust the second pulse width control signal provided to the third control switch Q3 so that the voltage obtained by the fan assembly 12 is essentially constant.Furthermore, by adjusting the second pulse width control signal supplied to the third control switch Q3, the voltage supplied to the fan assembly 12 can be increased or decreased, and the fan assembly 12 can be controlled to reach different rotational speeds.

[0041] Further, the fan driving circuit 30 includes a fourth control switch Q4, a third diode D4, a first feedback resistor 315, and a second feedback resistor 316. The negative electrode of the third diode D4 is connected to the positive electrode of the fan assembly 12, the negative electrode of the fan assembly 12 is connected to the positive electrode of the third diode D4 and a first conductive end of the fourth control switch Q4, and the control end of the fourth control switch Q4 is electrically connected to a fan enable terminal FAEN of the main control circuit 50. The second conductive end of the fourth control switch Q4 is grounded via the first feedback resistor 315, a node between the second conductive end of the fourth control switch Q4 and the first feedback resistor 315 is electrically connected to a load feedback terminal LOAD AD of the main control circuit 50 via the second feedback resistor 316, and a node between the second feedback resistor 316 and the main control circuit 50 is grounded by the third ground capacitor 317. Through the fourth control switch Q4, the voltage after being boosted by the second inductor L2 and the third control switch Q3 can be grounded through the fan assembly 12 to form a loop, thereby driving the fan assembly 12 to rotate, and the signal of the node between the second conductive end of the fourth control switch Q4 and the first feedback resistor 315 is sampled through the first feedback resistor 315 and fed back to the main control circuit 50, so that the main control circuit 50 can detect whether the rotation of the fan assembly 12 is blocked or the fan assembly 12 is short-circuited.

[0042] Example 3 is shown in Figs. 3-1 to 3-24.

[0043] Referring to Figures 3-1 to 3-3, the first embodiment of the present application provides a driving circuit for a portable fan, which can be used for multiple types of fans. Specifically, the driving circuit for the portable fan includes a main control circuit 11, a three-phase driving circuit 12, and a back electromotive force detection circuit 14.

[0044] The three-phase drive circuit 12 includes at least three signal input terminals 121 and three drive signal output terminals 122. The at least three signal input terminals 121 are electrically connected to the main control circuit 11, respectively, and receive control signals. The three drive signal output terminals 122 are electrically connected to three signal terminals (U, V, W) of the DC brushless fan motor, respectively, and output three-phase drive signals for driving and rotating the DC brushless fan motor. The back electromotive force detection circuit 14 includes three detection branches 141. Each detection branch 141 includes a detection terminal 1411 and a detection output terminal 1412 electrically connected to the detection terminal. The three detection terminals 1411 of the three detection branches 141 are electrically connected to the three drive signal output terminals 122, respectively. The three detection output terminals 1412 of the three detection branches 141 are respectively electrically connected to the main control circuit 11 and used to output a first detection signal, a second detection signal and a third detection signal to the main control circuit 11, so that the main control circuit 11 obtains the phase of the three-phase driving signal according to the first detection signal, the second detection signal and the third detection signal, and adjusts the control signal.

[0045] 3-3, the detection branch 141 includes a first detection resistor R1, a second detection resistor R2 and a third detection resistor R3, and the first detection resistor R1 and the second detection resistor R1 are connected in series. One end of the first detection resistor R1 remote from the second detection resistor R1 is the detection terminal 1411, one end of the second detection resistor R2 remote from the first detection resistor R1 is grounded, and the node between the first detection resistor R1 and the second detection resistor R2 is the detection output terminal 1412.

[0046] The three-phase driving circuit 12 can improve the energy saving performance and control performance of the fan motor, and can extend the life of the driving circuit and the fan of the portable fan. In addition, the back electromotive force detection circuit 14 described above allows the main control circuit 11 to easily obtain the phase of the DC brushless fan motor, and send a corresponding control signal to the three-phase driving circuit 12 to effectively control the driving of the DC brushless fan motor, and improve the reliability and stability of the driving.

[0047] 3-2, the three-phase driving circuit 12 includes a first transistor Q1, a second transistor Q2, a third transistor Q3, a fourth transistor Q4, a fifth transistor Q5, a sixth transistor Q6, a seventh transistor Q7, an eighth transistor Q8, and a ninth transistor Q9. First conduction terminals 1211 of the first transistor Q1, the second transistor Q2, and the third transistor Q3 are all connected to a power supply terminal 1212. A first conductive terminal 1211 of the fourth transistor Q4 is connected to the power supply terminal 1212, a first conductive terminal 1211 of the fifth transistor Q5 is connected to the power supply terminal 1212, a first conductive terminal 1211 of the sixth transistor Q6 is connected to the power supply terminal 1212, control terminals of the fourth transistor Q4, the fifth transistor Q5 and the sixth transistor Q6 are electrically connected to the main control circuit 11 respectively, and control terminals of the seventh transistor Q7, the eighth transistor Q8 and the seventh transistor Q9 are electrically connected to the control terminals of the fourth transistor Q4, the fifth transistor Q5 and the sixth transistor Q6 respectively, and are used to receive the control signal. The second conduction terminals 1213 of the fourth transistor Q4, the fifth transistor Q5 and the sixth transistor Q6 are all grounded, the first conduction terminal 1211 of the seventh transistor Q7 is connected to the second conduction terminal 1213 of the first transistor Q1, the second conduction terminal 1213 of the seventh transistor Q7 is grounded, the first conduction terminal 1211 of the eighth transistor Q8 is connected to the second conduction terminal 1213 of the second transistor Q2, the second conduction terminal 1213 of the transistor Q8 is grounded, the first conduction terminal 1211 of the ninth transistor Q9 is connected to the second conduction terminal 1213 of the third transistor Q3, and the second conduction terminal 1213 of the ninth transistor Q9 is grounded.The node between the first conduction terminal 1211 of the seventh transistor Q7 and the second conduction terminal 1213 of the first transistor Q1, the node between the first conduction terminal 1211 of the eighth transistor Q8 and the second conduction terminal 1213 of the second transistor Q2, and the node between the first conduction terminal 1211 of the ninth transistor Q9 and the second conduction terminal 1213 of the third transistor Q3 respectively function as the three driving signal output terminals 122, and the at least three signal input terminals 121 are three PWM signal input terminals, and the control signal includes three PWM signals.

[0048] As shown in FIG. 3-2, the driving circuit of the portable fan also includes a current detection circuit 15. The second conductive terminals 1213 of the seventh transistor Q7, the eighth transistor Q8, and the ninth transistor Q9 are all grounded via the current detection circuit 15, and the current detection circuit 15 is also electrically connected to the main control circuit 11. The current detection circuit 15 includes a sense resistor 151 and a sense capacitor 152. The second conductive terminals 1213 of the seventh transistor Q7, the eighth transistor Q8, and the ninth transistor Q9 are grounded via the sense resistor 151 and the sense capacitor 152 in turn, and a node between the sense resistor 151 and the sense capacitor 152 is electrically connected to the main control circuit 11. When an abnormal current occurs due to the current detection circuit 15, the main control circuit 11 controls the driving circuit of the portable fan to stop operating or to operate at a lower power, thereby providing overcurrent protection for the driving circuit of the portable fan, and improving the reliability and service life of the driving circuit of the portable fan.

[0049] 3-4 and 3-6, the driving circuit of the portable fan includes an interface circuit 16 and a charging management circuit 17. The interface circuit 16 is used to electrically connect an external power source to receive an external voltage. The charging management circuit 17 is electrically connected between the interface circuit 16 and a battery VBAT, and is used to receive the external voltage and charge the battery VBAT or output a supply voltage. The driving circuit of the portable fan includes a button 31. One end of the button 31 is connected to the main control circuit 11, and the other end is grounded. The driving circuit of the portable fan also includes an indicator light branch 19. The indicator light branch 19 includes a light-emitting diode and a resistor connected in series. The positive pole of the light-emitting diode is used to electrically connect with the main control circuit 11. The negative pole of the light-emitting diode is grounded.

[0050] Specifically, in this embodiment, the driving circuit of the portable fan can be applied to a neck fan and a handheld fan, but is not limited to the neck fan and the handheld fan, and can also be applied to portable fans such as a table fan, a stand fan, a handheld fan, a clip fan, a folding fan, etc. The two DC brushless fan motors are disposed on the left and right sides of the neck fan, respectively, and are used to rotate and drive the fan blades on the left and right sides of the neck fan.

[0051] As shown in FIG. 3-1, FIG. 3-2 and FIG. 3-5, the main control circuit 11 may include a main control chip 111 and an auxiliary chip 113. The main control circuit 11 includes a main control chip 111 and an auxiliary chip 113. The three-phase driving circuit 12, the back electromotive force detection circuit 14 and the DC brushless fan motor are all two in number, and are arranged in one-to-one correspondence. The main control chip 111 is electrically connected to one of the three-phase driving circuits 12, thereby outputting the control signal to one of the three-phase driving circuits 12 to drive the corresponding one of the DC brushless fan motors, and the back electromotive force detection circuit 14 is electrically connected to the corresponding one of the three-phase driving circuits 12, thereby outputting the corresponding first detection signal, the second detection signal and the third detection signal to the main control chip 111, thereby the main control chip 111 obtains the phase of the three-phase driving signal of one of the three-phase driving circuits 12, and adjusts the control signal output to one of the three-phase driving circuits 12. The auxiliary chip 113 is electrically connected to the other three-phase drive circuit 12, thereby outputting a control signal to the other three-phase drive circuit 12 to drive the corresponding other DC brushless fan motor, and the other back EMF detection circuit 14 is electrically connected to the corresponding three-phase drive circuit 12, thereby outputting the corresponding first detection signal, the second detection signal and the third detection signal to the auxiliary chip 113, thereby the auxiliary chip 113 obtains the phase of the three-phase drive signal of the other three-phase drive circuit 12 and adjusts the control signal output to the other three-phase drive circuit 12.

[0052] In this embodiment, the main control chip 111, the corresponding three-phase driving circuit 12, and the corresponding back electromotive force detection circuit 14 can be arranged in one module (e.g., a first circuit board) and arranged on the same side of the neck fan as the corresponding DC brushless fan motor. The auxiliary chip 113, the corresponding three-phase driving circuit 12, and the corresponding back electromotive force detection circuit 14 can be arranged in a different module (e.g., a second circuit board independent of the first circuit board) and arranged on the other side of the neck fan as the corresponding DC brushless fan motor. It can be seen that the above design improves rationality and compactness, and also improves the reliability of connection and operation. However, the layout of the three-phase driving circuit 12, the back EMF detection circuit 14, the main control chip 111 and the auxiliary chip 113 may be various. For example, the above-mentioned three-phase driving circuit 12, the back EMF detection circuit 14, the main control chip 111 and the auxiliary chip 113 may all be arranged on the same board, or the three-phase driving circuit 12 and the back EMF detection circuit 14 may be arranged on one circuit board, and the main control chip 111 and the auxiliary chip 113 may be arranged on another circuit board. This can be specifically selected according to actual needs, and will not be repeated here.

[0053] 3-7 and 3-8, the driving circuit of the portable fan includes the first connector 261 and a speed adjustment interface circuit 26 with the second connector 262. The first pin and the second pin of the first connector 261 are electrically connected to the main control chip 111 respectively, and the third pin of the first connector 261 is grounded. The first pin of the second connector 262 is connected to the battery VBAT through a first connection resistor on the one hand, and is connected to the auxiliary chip 113 through a second connection resistor on the other hand, the second pin of the second connector 262 is connected to the auxiliary chip 113 through a third connection resistor, and the third pin of the second connector 262 is grounded. In addition, each pin of the first connector 261 and the second connector 262 can also be electrically connected one by one, so that the rotation speeds of the two DC brushless fan motors can be synchronously adjusted.

[0054] Referring to Figs. 3-9 to 3-14, the second embodiment of the present application provides a driving circuit for a portable fan. The same parts of the driving circuit for the portable fan as those of the first embodiment will not be described. The following mainly describes the differences between the driving circuit for the portable fan of the second embodiment and that of the first embodiment. First, the main control circuit 11 of the second embodiment is different from the main control circuit 11 of the first embodiment, and the main control circuit 11 of the second embodiment may mainly include a main control chip 111.

[0055] 3-10, in this embodiment, the three-phase drive circuit 12 includes a first transistor Q1, a second transistor Q2, a third transistor Q3, a fourth transistor Q4, a fifth transistor Q5, and a sixth transistor Q6. A first conduction terminal 1211 of the first transistor Q1, the second transistor Q2, and the third transistor Q3 is connected to a power supply terminal 1212, a first conduction terminal 1211 of the fourth transistor Q4 is connected to a second conduction terminal 1213 of the first transistor Q1, a first conduction terminal 1211 of the fifth transistor Q5 is connected to a second conduction terminal 1213 of the second transistor Q2, a first conduction terminal 1211 of the sixth transistor Q6 is connected to a second conduction terminal 1213 of the third transistor Q3, a node between the first conduction terminal 1211 of the fourth transistor Q4 and the second conduction terminal 1213 of the first transistor Q1, The node between the first conduction terminal 1211 of the fifth transistor Q5 and the second conduction terminal 1213 of the second transistor Q2, and the node between the first conduction terminal 1211 of the sixth transistor Q6 and the second conduction terminal 1213 of the third transistor Q3 are respectively used as the three driving signal output terminals 122, and the control terminals of the first transistor Q1, the second transistor Q2, the third transistor Q3, the fourth transistor Q4, the fifth transistor Q5 and the sixth transistor Q6 are respectively electrically connected to the main control circuit 11 and used to receive the control signals, and the control signals include six PWM signals.

[0056] As shown in FIG. 3-10, the second embodiment is basically similar to the first embodiment in the following. The second conductive terminal 1213 of the sixth transistor Q6 is grounded through the current detection circuit 15, which is also electrically connected to the main control circuit 11, and the current detection circuit 15 includes a sense resistor 151 and a sense capacitor 152. The second conductive end 1213 of the sixth transistor Q6 is grounded through the sense resistor 151. The sense capacitor 152 is connected in parallel with the sense resistor 151, and the node between the sense resistor 151 and the second conductive end 1213 of the sixth transistor Q6 is electrically connected to the main control circuit 11. The current detection circuit 15 also includes a first series resistor 153, a second series resistor 154 and a parallel resistor 155. The parallel resistor 155 is connected in parallel with the sense resistor 151. The first series resistor 153 is connected between one end of the sense capacitor 152 and one end of the sense resistor 151, and the second series resistor 154 is connected between the other end of the sense capacitor 152 and the other end of the sense resistor 151. Through the current detection circuit 15, when an abnormal current occurs, the main control circuit 11 controls the portable fan driving circuit to stop operating or to operate at a lower power, thereby providing overcurrent protection for the portable fan driving circuit and improving the reliability and service life of the portable fan driving circuit.

[0057] As shown in FIG. 3-11, the back electromotive force detection circuit 14 of the second embodiment is basically similar to the back electromotive force detection circuit 14 of the first embodiment, and therefore a description thereof will be omitted here.

[0058] As shown in FIG. 3-12, the driving circuit of the portable fan also includes a transistor temperature detection circuit 24. The transistor temperature detection circuit 24 can be disposed adjacent to each transistor of the three-phase driving circuit 12, and includes a first voltage dividing resistor 241 and a thermistor 242 connected in series. The thermistor 242 is used to sense the temperature of each transistor of the three-phase driving circuit 12, and the node between the first voltage dividing resistor 241 and the thermistor 242 is electrically connected to the main control circuit 11 and used to output a temperature signal, so that the main control circuit 11 controls whether the driving circuit of the portable fan enters a temperature protection state according to the temperature signal, the thermistor 242 is connected between the first voltage dividing resistor 241 and ground, and the transistor temperature detection circuit 24 includes a voltage stabilizing capacitor 243 connected in parallel with the thermistor 242. The main control circuit 11 can know through the transistor temperature detection circuit 24 whether the temperature of each transistor of the three-phase drive circuit 12 is abnormal, and when an abnormality occurs, the main control circuit 11 stops the operation of the portable fan drive circuit or controls it to operate at a lower power, thereby providing overcurrent protection for the portable fan drive circuit and improving the reliability and service life of the portable fan drive circuit.

[0059] As shown in FIG. 3-13, the driving circuit of the portable fan includes a battery voltage detection circuit 25 electrically connected between the positive pole of the battery VBAT and ground, and the output terminal of the battery voltage detection circuit 25 is electrically connected to the main control circuit 11. Through the battery voltage detection circuit 25, the main control circuit 11 can know whether the battery voltage is normal, and when the battery voltage is abnormal, it stops the operation of the driving circuit of the portable fan or controls it to operate at a lower power, so as to provide overcurrent protection for the driving circuit of the portable fan, and improve the reliability and service life of the driving circuit of the portable fan.

[0060] Specifically, the battery voltage detection circuit 25 includes a second voltage dividing resistor 251 and a third voltage dividing resistor 252 connected in series, and a node between the second voltage dividing resistor 251 and the third voltage dividing resistor 252 is electrically connected to the main control circuit 11. It can be seen that the above-mentioned battery voltage detection circuit 25 has a simple configuration, high reliability, and low cost.

[0061] As shown in Fig. 3-14, the driving circuit of the portable fan in the second embodiment of the present application also has a burn interface 28, which is used to burn a control program into the main control circuit 11. The burn interface 28 may be an SWD burn interface, and is not limited to the above.

[0062] 15-16, a third embodiment of the present application provides a driving circuit for a portable fan. The same parts of the driving circuit for a portable fan of the third embodiment as those of the driving circuit for a portable fan of the second embodiment will not be described again. Hereinafter, differences between the driving circuit for a portable fan of the third embodiment and the driving circuit for a portable fan of the second embodiment will be mainly described.

[0063] As shown in Figures 3-15 to 3-17, the three-phase drive circuit 12 of the third embodiment is basically the same as the three-phase drive circuit 12 of the second embodiment. The main control circuit 11 of the third embodiment is different from the main control circuit 11 of the second embodiment in that the main control circuit 11 includes a main control chip 111 and three three-phase control chips 112. Each of the three-phase control chips 112 is electrically connected to the main control chip 111 and the three-phase drive circuit 12.

[0064] As shown in FIG. 3-16 and FIG. 3-18, the portable fan driving circuit also includes a filter capacitor 253 and a sampling resistor 254 connected in series. The sampling resistor 254 is connected between the filter capacitor 253 and ground. A node between the filter capacitor 253 and the sampling resistor 254 is electrically connected to the main control circuit 11. Furthermore, the portable fan driving circuit also includes a signal amplifier circuit 29. An input terminal of the signal amplifier circuit 29 is connected to a node between the filter capacitor 253 and the sampling resistor 254. The signal amplifier circuit 29 is used to amplify the signal sampled by the sampling resistor 254 (i.e., the signal at the node between the filter capacitor 253 and the sampling resistor 254) and provide the amplified signal to the main control circuit 11. As a result, the main control circuit 11 of the portable fan drive circuit can sensitively detect abnormal voltage and current signals if an abnormality occurs in the entire portable fan drive circuit, and further, the main control circuit 11 can perform abnormality protection operations such as stopping operation or reducing the fan rotation speed, thereby improving the safety of use of the portable fan drive circuit.

[0065] As shown in FIG. 3-19, the transistor temperature detection circuit 24 of the third embodiment is basically the same as that of the second embodiment, and therefore, a description thereof will be omitted here.

[0066] Referring to Fig. 3-20, Fig. 3-20 is a schematic diagram of a lighting control circuit 30 of a driving circuit of a portable fan provided in the third embodiment of the present application. The lighting control circuit 30 includes a light emitting element 301 and a control switch 302. The positive electrode of the light emitting element 301 receives a driving voltage, and the negative electrode of the light emitting element 301 is grounded through a resistor and two conductive terminals of the control switch 302. The control terminal of the control switch 302 is electrically connected to the main control circuit 11, so that the main control circuit 11 outputs a lighting control signal to the control terminal of the control switch 302 to control the light emission of the light emitting element 301.

[0067] As shown in FIG. 3-21, the driving circuit of the portable fan also includes the Hall detection circuit 23. The Hall detection circuit 23 is electrically connected to the main control circuit 11 and is used to detect the magnetic field generated by the DC brushless fan motor and output a Hall detection signal to the main control circuit 11. Thus, the main control circuit 11 can obtain the rotor position of the DC brushless fan motor based on the Hall detection signal and provide a corresponding control signal to control the operation of the three-phase driving circuit 12. In this case, the fan using the driving circuit of the portable fan has a short start-up time and no start-up jitter, and can achieve a better user experience.

[0068] As shown in FIG. 3-21, the Hall detection circuit 23 also includes a motor temperature detection element 232 connected between the Hall element 231 of the Hall detection circuit 23 and the main control circuit 11. The motor temperature detection element 232 may be a sampling resistor. The main control circuit 11 knows whether the temperature of the DC brushless fan motor is abnormal through the motor temperature detection element 232, and controls the portable fan driving circuit to stop operating or operate at a lower power when an abnormality occurs, so as to provide over-temperature protection for the portable fan driving circuit, and improve the reliability and service life of the portable fan driving circuit.

[0069] As shown in Figures 3-17 and 3-22, the driving circuit of the portable fan also includes a voltage conversion circuit 20. The voltage conversion circuit 20 is used to receive a battery voltage (VB+), convert the battery voltage into a driving voltage (such as 15V), and supply the driving voltage to the power terminals of the three three-phase control chips 112. The main control chip 111 is used to output a main control signal to the three three-phase control chips 112, so that the three three-phase control chips 112 output the control signals to the three-phase driving circuits 12, respectively.

[0070] The driving circuit of the portable fan also includes a switch control circuit 21. The switch control circuit 21 is electrically connected to a battery VBAT, the voltage conversion circuit 20 and the main control circuit 11, and is used to control the operation of the voltage conversion circuit 20. The switch control circuit 21 includes a button 211, a first switch tube 212, a second switch tube 213 and a third switch tube 214. The two conductive terminals of the first switch tube 212 are respectively connected to the positive pole of the battery VBAT and the input terminal of the voltage conversion circuit 20. The control terminal of the first switch tube 212 is grounded through the two conductive terminals of the third switch tube 214, the positive electrode of the battery VBAT is connected to the control terminal of the third switch tube 214 through the two conductive terminals of the first switch tube 212 and a unidirectional diode 215, the control terminal of the second switch tube 213 is grounded through the button 211, the control terminal of the third switch tube 214 is electrically connected to the main control circuit 11, and the node between the second switch tube 213 and the unidirectional diode 215 is electrically connected to the switch signal terminal of the main control circuit 11.

[0071] When the button 211 is pressed and turned on, the second switch tube 213 is turned on, the third switch tube 214 is turned on, and the node between the second switch tube 213 and the unidirectional diode 215 outputs a first switch signal (ON) to the switch signal terminal of the main control circuit 11, and the first switch tube 212 is turned on, so that the battery voltage of the battery VBAT is supplied to the voltage conversion circuit 20. When the button 211 is released, the second switch 213 is turned off, and the main control circuit 11 outputs a power supply open signal to the control terminal of the third switch tube 214 in response to the first switch signal to maintain the conduction of the third switch tube 214, and the battery voltage of the battery VBAT is supplied to the voltage conversion circuit 20.

[0072] Furthermore, when the battery voltage of the battery VBAT is supplied to the voltage conversion circuit 20, if the button 211 is pressed again to be turned on, the node between the second switch tube 213 and the unidirectional node 215 outputs a second switch signal (OFF) to the switch signal terminal of the main control circuit 11, and the main control circuit 11 outputs a power supply cut-off signal according to the second switch signal to the control terminal of the third switch tube 214, controls the third switch tube 214 to be turned off, and the battery voltage of the battery VBAT cannot be supplied to the voltage conversion circuit 20 until the first switch tube 212 is turned off and the button 211 is pressed again to be turned on.

[0073] The button 211, the first switch 212, the second switch 213 and the third switch 214 cooperate with the main control circuit 11 to control whether or not the battery voltage of the battery VBAT is supplied to the voltage conversion circuit 20, which has the advantages of not only simple control logic but also high reliability.

[0074] As shown in FIG 3-23, the driving circuit of the portable fan also includes a DC conversion circuit 22. The DC conversion circuit 22 is used to receive the driving voltage (such as a DC voltage of 15V) and convert it to another DC operating voltage (for example, a DC operating voltage of 3.3V or 5V).

[0075] 3-24, an embodiment of the present application provides a portable fan 2. The portable fan 2 includes a portable fan driving circuit 3, a DC brushless fan motor 4, and a fan blade 5 driven by the DC brushless fan motor. The portable fan driving circuit 3 adopts the portable fan driving circuit described in each of the above embodiments.

[0076] Compared with the prior art, in the portable fan driving circuit and the portable fan 2 of the above embodiment, by using the main control circuit 11, the three-phase driving circuit 12, the back electromotive force detection circuit 14 and the DC brushless fan motor, the energy-saving performance and control performance of the fan motor are improved, and the reliability of the portable fan driving circuit and the portable fan 2 is not only improved, but the service life of the portable fan driving circuit and the portable fan 2 is extended, and by using a DC brushless fan motor, the structure of the portable fan 2 is simplified and miniaturized, thereby improving the market competitiveness of the product.

[0077] Example 4 is shown in Figures 4-1 to 4-11.

[0078] The present application provides a handheld fan, in which an air passage 11 is formed by an inner shell 1, both sides of the air passage 11 are respectively connected to an air inlet 23 and an air outlet 24, at least a part of a fan assembly 3 is disposed in the air passage 11, an outer shell 2 is disposed to cover the outside of the inner shell 1, one side of a wiring opening 12 of the inner shell 1 faces an electrical connection part of the fan assembly 3, and the other side of the wiring opening 12 is used to face an electrical connection part of a handheld part 5 of the handheld fan, and the electrical connection part of the fan assembly 3 is electrically connected to the electrical connection part of the handheld part 5 through a conductor passing through the wiring opening 12. As a result, the wiring opening 12 of the inner shell 1 allows the conductor connected to the electrical connection part of the fan assembly 3 to enter and exit, and the conductor connected to the electrical connection part of the fan assembly 3 passes through the wiring opening 12 from a position directly opposite the electrical connection part of the handheld part 5 of the handheld fan, and then the conductor is again connected to the electrical connection part of the handheld part 5 of the handheld fan, which helps to shorten the length of the conductor, increase the durability, and improve the aesthetics of the wiring. This achieves the technical effects of improving the stability of the wiring, improving the aesthetics of the wiring, and improving the durability.

[0079] 4-1 to 4-11, FIG. 4-1 is a structural schematic diagram of a handheld fan provided by an embodiment of the present application, FIG. 4-2 is a structural schematic diagram of a mounting bracket 6 in the handheld fan provided by an embodiment of the present application, FIG. 4-3 is a structural schematic diagram of a handheld part 5 in the handheld fan provided by an embodiment of the present application, FIG. 4-4 is a structural schematic diagram of a wiring opening 12 in the handheld fan provided by an embodiment of the present application, FIG. 4-5 is a first structural schematic diagram of a wiring groove 21 in the handheld fan provided by an embodiment of the present application, and FIG. 4-6 is a handheld part provided by an embodiment of the present application. FIG. 4-7 is a structural schematic diagram of the range knob assembly 71 and the protection switch button assembly 72 of the handheld fan provided by the embodiment of the present application, FIG. 4-8 is a structural schematic diagram of the inner shell 1 and the outer shell 2 of the handheld fan provided by the embodiment of the present application, FIG. 4-9 is a structural schematic diagram of the air inlet 23 and the air outlet 24 of the handheld fan provided by the embodiment of the present application, FIG. 4-10 is an enlarged schematic diagram of a portion A of FIG. 4-9, and FIG. 4-11 is a structural schematic diagram of the fan assembly 3 in the handheld fan provided by the embodiment of the present application. The handheld fan provided by the embodiment of the present application comprises an inner shell 1, an outer shell 2 and a fan assembly 3, and the inner shell 1, the outer shell 2 and the fan assembly 3 will now be described in detail respectively.

[0080] The inner shell 1, the fan assembly 3 and the outer shell 2 are as follows.

[0081] The inner shell 1 is formed with an air passage 11, an air inlet 23 communicating with one side of the air passage 11, and an air outlet 24 communicating with the other side of the air passage 11, and at least a part of the fan assembly 3 is disposed in the air passage 11. The inner shell 1 has a wiring opening 12, one side of which faces an electrical connection portion of the fan assembly 3 and the other side of which faces an electrical connection portion of a handheld portion 5 of the handheld fan, and the electrical connection portion of the fan assembly 3 is electrically connected to the electrical connection portion of the handheld portion 5 through a conductor passing through the wiring opening 12. The handheld portion 5 has an attachment opening 4, which is connected to the outer shell 2, and which faces the other side of the wiring opening 12. The handheld fan provided in the embodiment of the present application includes a mounting bracket 6 arranged on the handheld part 5, a second circuit board 73, and a range knob assembly 71, at least a part of the mounting bracket 6 is arranged on the mounting opening 4, the mounting bracket 6 is connected to the inner shell 1, and the mounting bracket 6 has an accommodating space 61 for passing a conductor. The electrical connection part of the handheld part 5 includes a first circuit board 7, the first circuit board 7 is arranged on the mounting bracket 6, and the first circuit board 7 is inserted into the electrical connection part of the fan assembly 3 through a conductor. The second circuit board 73 is arranged on the mounting bracket 6, and the second circuit board 73 is inserted into the first circuit board 7 through a conductor, and the range knob assembly 71 is arranged on the mounting bracket 6, and the range knob assembly 71 is connected to the second circuit board 73. The second circuit board 73 and the first circuit board 7 are arranged opposite to each other. The outer shell 2 is used to cover the outside of the inner shell 1. A baffle 22 is disposed in the inner wall 1, and the baffle 22 and the inner wall 1 are surrounded to form a wiring groove 21. At least a portion of the first circuit board 7 is disposed in the wiring groove 21.

[0082] Specifically, an air passage 11 formed inside the inner shell 1 is used for circulating gas, and gas flows into the air passage 11 from an air inlet 23, and the gas that flows into the air passage 11 is discharged to the air passage 11 from an air outlet 24. The outer shell 2 is disposed to cover the outside of the inner shell 1. The inner shell 1 is provided with a wiring opening 12 for passing a conductor, and both sides of the wiring opening 12 face the electrical connection part of the fan assembly 3 and the electrical connection part of the handheld part 5 of the handheld fan, respectively. The electrical connection part of the fan assembly 3 may refer to a circuit board connected to the fan motor, and the conductor connecting the circuit board passes through the wiring opening 12 and is then connected to the first circuit board 7 of the electrical connection part of the handheld part 5. The mounting opening 4 of the handheld part 5 faces the wiring opening 12, the receiving space 61 of the mounting bracket 6 is connected to the mounting opening 4 of the handheld part 5, the first circuit board 7 and the second circuit board 73 are distributed opposite to each other on the mounting bracket 6, the conductor passing through the wiring opening 12 can be inserted into the first circuit board 7 arranged on the mounting bracket 6 after passing through the mounting opening 4 of the handheld part 5, for example, one end of the conductor passing through the wiring opening 12 can be inserted into the first circuit board 7 via a connector, thereby facilitating the mutual connection or separation of the conductor and the first circuit board 7. The second circuit board 73 can be inserted into the first circuit board 7 via a conductor, for example, the second circuit board 73 can be connected to a connector connected to the first circuit board 7 via a conductor, thereby facilitating the mutual connection or separation of the second circuit board 73 and the first circuit board 7. Range knob assembly 71 connected to second circuit board 73 is used to adjust the rotation speed of the fan blades in fan assembly 3 to control the wind speed, for example, the range of the fan can be adjusted by rotating the knob in range knob assembly 71. The power of battery 8 can be checked by pressing the knob in range knob assembly 71. A baffle 22 is disposed at a position of inner shell 1 close to handheld portion 5, and the diameter of inner shell 1 gradually increases along the direction from air inlet 23 to air outlet 24, so that a recessed space is formed inward at one end of inner shell 1 close to air inlet 23.The baffle 22 may be disposed in a space recessed inward, and the inner shell 1 and the baffle 22 are surrounded to form a wiring groove 21, and a part of the first circuit board 7 can extend into the inside of the wiring groove 21, and at the same time, the inside of the wiring groove 21 has a space capable of accommodating a conductor connected to the first circuit board 7. Alternatively, the entire first circuit board 7 is located outside the wiring groove 21, a part of the electric wire connected to the first circuit board 7 is located inside the wiring groove 21, and the other part of the electric wire is extended outside the wiring groove 21 and then connected to the first circuit board 7, thereby improving the utilization rate of the space.

[0083] The handheld fan provided in embodiment 1 of the present application may also include a protection switch button assembly 72 and a battery 8, the protection switch button assembly 72 is disposed on the mounting bracket 6, and the protection switch button assembly 72 is electrically connected to the first circuit board 7. The battery 8 is disposed on the handheld part 5, and the battery 8 is plugged into the first circuit board 7 via a conductor.

[0084] Specifically, a battery 8 may be installed in the handheld unit 5, and the battery 8 may be mutually plugged into the first circuit board 7 via a conductor, so that power may be supplied to the fan assembly 3 via the battery 8. A protection switch button assembly 72 electrically connected to the first circuit board 7 may control the on or off of a circuit powered by the battery 8. For example, the protection switch button assembly 72 may employ a slide switch, and when the button of the protection switch button assembly 72 is slid to one end, the circuit is turned on, and at this time, the motor in the fan assembly 3 is operated to rotate the fan blades. When the button of the protection switch button assembly 72 is slid to the other end, the circuit is turned off, and at this time, the motor of the fan assembly 3 is not operated, and the fan blades do not rotate, so that it is possible to prevent an operator from accidentally operating the fan after accidentally touching the range knob assembly 71.

[0085] The present application provides a handheld fan, wherein an air passage 11 is formed through an inner shell 1, both sides of the air passage 11 are respectively connected to an air inlet 23 and an air outlet 24, at least a portion of a fan assembly 3 is disposed within the air passage 11, an outer shell 2 is disposed covering the outside of the inner shell 1, one side of a wiring opening 12 in the inner shell 1 faces an electrical connection of the fan assembly 3, and the other side of the wiring opening 12 faces directly to an electrical connection of a handheld part 5 of the handheld fan, and the electrical connection of the fan assembly 3 is electrically connected to the electrical connection of the handheld part 5 via a conductor passing through the wiring opening 12. Thus, the wiring opening 12 of the inner shell 1 allows the entrance of the conductor connected to the electrical connection part of the fan assembly 3, and the conductor connected to the electrical connection part of the fan assembly 3 passes through the wiring opening 12 from a position directly opposite the electrical connection part of the handheld part 5 of the handheld fan, and then the conductor is again connected to the electrical connection part of the handheld part 5 of the handheld fan, which helps to shorten the length of the conductor, improve durability, and improve the aesthetics of the wiring. This achieves the technical effects of improving the stability of the wiring, improving the aesthetics of the wiring, and improving durability.

[0086] In order to describe the handheld fan provided by the present application in detail, one handheld fan is described in detail in the above embodiments, but based on the similar application concept, the present application also provides another handheld fan, please refer to embodiment 2 for details.

[0087] A second embodiment of the present application provides a handheld fan.

[0088] The present application provides a handheld fan, in which an air passage 11 is formed through an inner shell 1, both sides of the air passage 11 are respectively connected to an air inlet 23 and an air outlet 24, at least a part of a fan assembly 3 is disposed within the air passage 11, an outer shell 2 is disposed covering the outside of the inner shell 1, one side of a wiring opening 12 of the inner shell 1 faces an electrical connection of the fan assembly 3, and the other side of the wiring opening 12 faces directly to an electrical connection of a handheld part 5 of the handheld fan, and the electrical connection of the fan assembly 3 is electrically connected to the electrical connection of the handheld part 5 via a conductor passing through the wiring opening 12. As a result, the wiring opening 12 of the inner shell 1 allows the conductor connected to the electrical connection part of the fan assembly 3 to enter and exit, and the conductor connected to the electrical connection part of the fan assembly 3 passes through the wiring opening 12 from a position directly opposite the electrical connection part of the handheld part 5 of the handheld fan, and then the conductor is again connected to the electrical connection part of the handheld part 5 of the handheld fan, which helps to shorten the length of the conductor, improve durability, and improve the aesthetics of the wiring. This achieves the technical effects of improving the stability of the wiring, improving the aesthetics of the wiring, and improving durability.

[0089] Example 5 is shown in Figs. 5-1 to 5-6.

[0090] As shown in Figures 5-1 and 5-2, the portable fan includes a shell 1, a fan assembly 2, a motor 3, and a drive circuit board 4. The shell 1 is provided with an air inlet 161, a housing cavity 162, and an air outlet 163, which are connected to each other. The fan assembly 2, the motor 3, and the drive circuit board 4 are housed in the shell 1. The drive circuit board 4 is electrically connected to the motor 3 to drive and rotate the fan assembly 2. Air is blown from the air inlet 161 through the housing cavity 162 and from the air outlet 163.

[0091] As shown in FIG. 5-1 to FIG. 5-2, the shell 1 includes a front shell 11 and a rear shell 12, the front shell 11 includes a first wind shell 111 and a first handheld shell 112, the rear shell 12 includes a second wind shell 121 and a second handheld shell 122, the first wind shell 111 and the second wind shell 121 form an exhaust section 16, and the first hand shell 112 and the second hand shell 122 form a handheld section 17. It can be understood that the first wind shell 111 and the second wind shell 121 may be matched front to back, or may be matched left to right. The first handheld shell 112 and the second handheld shell 122 may be matched front to back, or may be matched left to right. The handheld section 17 is provided with a switch 5, an interface 6, and a battery 7. In this embodiment, the switch 5 is an infinite speed adjustment switch 5. Of course, in other embodiments, the first handheld shell 112 and the second handheld shell 122 may not be arranged, or other common forms such as a desk fan, a neck fan, a clip fan, a stand fan, etc. may be arranged.

[0092] As shown in FIG. 5-2 to FIG. 5-4, the first wind shell 111 includes a first outer shell and a first inner shell that match the inside and outside, the first inner shell and the first outer shell are arranged in direct contact with each other, and both the first inner shell and the first outer shell are horizontally extended forward. The second wind shell 121 includes a second outer shell and a second inner shell that match the inside and outside, the rear ends of the second outer shell and the second inner shell are spaced apart and connected via a connector, the second outer shell is horizontally extended forward, the second inner shell is first horizontally extended from the rear to the front, and then is expanded and extended outward along the radial direction, the front end of the second inner shell is connected to the front end of the second outer shell, and the front end of the second inner shell is abutted against the rear end of the first inner shell. In this embodiment, the first outer shell and the second outer shell are integrally formed. Of course, in other embodiments, the first outer shell and the second outer shell may be formed separately. The first wind shell 111 and the second wind shell 121 both have a double shell structure, which is more stable, and the shape change of the second inner shell is favorable to pressurize the wind, making the wind force stronger and the wind blowing distance longer. Of course, in other embodiments, the first wind shell 111 and / or the second wind shell 121 may be a single-layer shell structure.

[0093] As shown in FIG. 5-1 and FIG. 5-2, the shell 1 includes a pressing member 13 disposed in the first window shell 111. A plurality of connecting blades 14 are connected to the pressing member 13 and the front shell 11, and the pressing member 13 is formed with a base 131 and a sleeve 132. The base 131 is located between the front end and the rear end of the pressing member 13, and a clearance space 1321 is formed behind the pressing member 13, and the base 131 is formed with a receiving portion 1322 in front of the pressing member 13. The sleeve 132 protrudes from the base 131 toward the receiving cavity 162, that is, the sleeve 132 extends rearward from the base 131, and the sleeve 132 is hollow.

[0094] As shown in Fig. 5-1 and Fig. 5-2, the air inlet 161 is located in a semi-inner region of the second inner shell, and the air outlet 163 is located in a region between the pressurizing member 13 and the first inner shell in the radial direction. The fan assembly 2 includes a hub 21 and a plurality of fan blades 22 arranged at intervals on the outer surface of the hub 21, the hub 21 includes a guide surface 212 that increases in the radial direction from the back to the front, the pressurizing part 13 includes a pressurizing surface 133 that increases in the radial direction from the back to the front, and the air guide surface 212 and the pressurizing surface 133 are arranged close to each other so that the wind blows forward smoothly. A radially outward air duct is formed from the air inlet 161 to the air outlet 163, and a larger air outlet surface is formed so that the wind is pressurized in the shell 1.

[0095] As shown in Figures 5-1 to 5-4, the fan assembly 2 includes the hub 21 and a plurality of fan blades 22 arranged at intervals on the outer surface of the hub 21. The hub 21 has an air guide surface 212 that increases radially from the rear to the front, and the pressurizing member 13 has a pressurizing surface 133 that increases radially from the rear to the front, and the air guide surface 212 and the pressurizing surface 133 are installed close to each other and spaced apart, so that the wind blows smoothly forward. A radially outward air passage is formed from the air inlet 161 to the air outlet 163, and the wind is pressurized in the shell 1, forming a larger air outlet surface.

[0096] As shown in Figs. 5-1 to 5-4, the fan assembly 2 includes the hub 21 and a plurality of fan blades 22 arranged at intervals on the outer surface of the hub 21. A rotating shaft 23 is fixed to the center inside the hub 21. The motor 3 includes a stator 31 and a rotor 32, and the stator 31 and the rotor 32 are housed in the hub 21. The hub 21 includes a ring-shaped extended wall 211, and the stator 31 and the rotor 32 are housed in the extended wall 211. The stator 31 is sleeved on the outside of the sleeve 132, the stator 31 includes a coil 311, and the rotor 32 is disposed between the stator 31 and the hub 21 in the radial direction, the rotating shaft 23 is inserted into the sleeve 132, and the extended wall 211, the stator 31, and the rotor 32 extend forward into the clearance space 1321.

[0097] 5-1 and 5-2, the extension wall 211 extends forward beyond the wind guide surface 212, and the wind guide surface 212 and the pressurizing surface 133 are disposed close to each other with a gap therebetween, so that a gap between the wind guide surface 212 and the pressurizing surface 133 is offset from the front end of the extension wall 211, making it difficult for dust to enter the extension wall 211. Neither the stator 31 nor the rotor 32 extends forward beyond the extension wall 211, and the extension wall 211, the stator 31, and the rotor 32 extend forward into the clearance space 1321, so that the extension wall 211, the stator 31, and the rotor 32 are partially accommodated in the clearance space 1321.

[0098] 5-1 and 5-2, the driving circuit board 4 is not disposed between the base 131 and the stator 31, the battery 7 is electrically connected to the driving circuit board 4, and the driving circuit board 4 is electrically connected to a lead wire of the coil 311 to rotate and drive the fan assembly 2, and air passes from the air inlet 161 through the accommodating cavity 162 and is then blown out from the air outlet 163. In this embodiment, the driving circuit board 4 is accommodated in the accommodating portion 1322 formed by the base 131 facing forward, and the front end of the pressing member 13 further includes a front cover 15, which is located at the front end of the accommodating portion 1322 and recessed rearward to form a negative pressure region 151. By positioning the front cover 15, on the one hand, the accommodating section 1322 is covered and the drive circuit board 4 is shielded and protected, and on the other hand, the negative pressure area 151 formed by the front cover 15 being recessed rearward can supply compensating air to the air outlet 163 and increase the air volume at the air inlet 163.

[0099] As shown in Figures 5-1 to 5-4, in this embodiment, the motor 3 is a three-phase motor, and the coil 311 includes 12 windings, and the number of windings is relatively large, so that the internal space of the motor 3 is limited. Since the driving circuit board 4 is not installed between the base 131 and the stator 31, the electrical connection between the lead wire of the coil 311 and the driving circuit board 4 is simpler and more convenient, and at the same time, the space between the base 131 and the stator 31 can be further reduced, so that the internal space distribution of the portable fan is more reasonable, and the miniaturization of the portable fan is realized.

[0100] As shown in Fig. 5-5, Fig. 5-5 is a schematic diagram of an embodiment of a portable fan in this application. The main differences from the previous embodiment are as follows: the driving circuit board 4 is accommodated in the handheld part 17 and is located between the switch 5 and the interface 6, and the switch 5 is connected to the driving circuit board 4 or the interface 6 is connected to the driving circuit board 4. The other structures and characteristics are basically the same as those of the first embodiment, and the description is omitted here.

[0101] As shown in Fig. 5-6, Fig. 5-6 is a schematic diagram of an embodiment of a portable fan in this application. The main difference from the previous embodiment is that the driving circuit board 4 is accommodated in the handheld part 17 and located below the battery 7. The other structures and characteristics are basically the same as those of the first embodiment, and the description is omitted here.

[0102] The above are merely specific embodiments of the present application, and do not limit the scope of protection of the present application. Any equivalent structural or equivalent process transformation carried out using the contents of the specification and drawings of the present application, or directly or indirectly applying it to other related technical fields, are also included in the scope of patent protection of the present application.

Claims

1. A portable fan including an air duct portion, a blower portion, and a handheld portion, The air duct part includes a main body, the main body is provided with an air guide cavity, the air duct part is provided with an air outlet and an air inlet at opposite ends, the air outlet and the air inlet are both connected to the air guide cavity, and a positioning boss is disposed within the main body; The blower includes a rotating blade and a drive unit drivingly connected to the rotating blade, the rotating blade being rotatably mounted in the air guide cavity and disposed toward the air outlet, the drive unit includes a stator and a rotor sleeved on the outside of the stator, the rotor is fixedly mounted on the rotating blade and disposed coaxially with the rotating blade, and the stator is fixedly sleeved on the positioning boss, the handheld portion is connected to the air duct portion, a mounting cavity is provided within the handheld portion, a power supply assembly is mounted in the mounting cavity, and the power supply assembly is electrically connected to the driving portion.

2. 2. The portable fan of claim 1, wherein the main body includes a first shell and a second shell, the first shell is connected to the second shell, the air guide cavity is formed between the first shell and the second shell, the air inlet is disposed in the first shell, the air outlet is disposed in the second shell, the positioning boss is disposed in the second shell, and the positioning boss extends along an extension direction of the air guide cavity.

3. a fixing hole is provided in the rotating blade, an axis of the fixing hole is aligned with an axis of the rotating blade, the blower section includes a rotating shaft, a first end of the rotating shaft is fixedly inserted into the fixing hole, a positioning hole is provided inside the positioning boss, an axis of the positioning hole is aligned with an axis of the rotating shaft, and a second end of the rotating shaft is rotatably inserted into the positioning hole, 2. The portable fan of claim 1, wherein the blower unit includes a bearing unit, an outer ring of the bearing unit is fixed to the positioning hole, an inner ring of the bearing unit is sleeved onto the second end of the rotating shaft, the bearing unit includes a rolling bearing, the blower unit further includes a limiting member, the limiting member is disposed on the second end of the rotating shaft, the bearing unit is located between the limiting member and the first end of the rotating shaft, the number of the bearing units is multiple, an inner flange is provided on an inner wall of the positioning hole, and the inner flange is disposed between two adjacent bearing units such that the two adjacent bearing units are disposed at a distance from each other, the bearing unit includes a sliding bearing, and the blower unit further includes two seal rings, both of which are sleeved onto the rotating shaft and respectively disposed on both sides of the sliding bearing.

4. 3. The portable fan of claim 2, wherein the handheld part includes a third shell and a fourth shell, the third shell is connected to the fourth shell, and the mounting cavity is formed between the third shell and the fourth shell, the first shell includes a main body and an air duct lining, the air duct lining is disposed on the main body, an air duct is disposed within the air duct lining, and the air guide cavity is formed between the air duct lining and the second shell.

5. the drive unit is a three-phase motor, the handheld unit is provided with a charging port, the charging port is electrically connected to the power supply assembly, and / or 3. The portable fan of claim 2, wherein the air duct portion and the handheld portion are fixedly connected or pivotally connected to each other so as to be rotatable relative to each other.

6. The control circuit of the portable fan includes a charging power supply circuit, a fan driving circuit, a control switch and a main control circuit; The charging and powering circuit is used to electrically connect an external power source and a power supply assembly, thereby receiving an external voltage to charge the power supply assembly, and outputting a power supply voltage; the fan drive circuit is electrically connected to the charging and power supply circuit and the rotating blades, and is used to drive and rotate the rotating blades; a control end of the control switch is used to receive the external voltage and is grounded; a first conductive end of the control switch is used to electrically connect to the power supply assembly and receive the output voltage of the power supply assembly; a second conductive end of the control switch is used to electrically connect to the fan driving circuit; the control switch is turned off when receiving the external voltage and turned on when not receiving the external voltage; and 2. The portable fan according to claim 1, wherein the main control circuit is electrically connected to the charging power supply circuit, the fan driving circuit, and the control switch.

7. 7. The portable fan of claim 6, wherein the charging and power supply circuit includes a charging port and a charging management chip, a power terminal of the charging port receives the external voltage and is electrically connected to a charging input pin of the charging management chip, the power terminal of the charging port is electrically connected to a negative electrode of a constant-voltage discharge tube and a positive electrode of the constant-voltage discharge tube is grounded, a switch pin of the charging management chip is used to electrically connect a positive electrode of the power supply assembly through a first inductor, a boost output pin of the charging management chip is used to output the power supply voltage, and a boost input pin of the charging management chip is connected to a node between the power supply assembly and the first inductor through a first connecting resistor on the one hand and grounded through a first grounding capacitor on the other hand.

8. A driving circuit for a portable fan including a main control circuit, a three-phase driving circuit, and a back electromotive force detection circuit, the three-phase driving circuit includes at least three signal input terminals and three driving signal output terminals, the at least three signal input terminals are electrically connected to the main control circuit 11 respectively to receive control signals, the three driving signal output terminals are electrically connected to three signal terminals (U, V, W) of the DC brushless fan motor respectively to output three-phase driving signals for driving the DC brushless fan motor to rotate; and the back electromotive force detection circuit includes three detection branches, each detection branch includes a detection terminal and a detection output terminal electrically connected to the detection terminal, the three detection terminals of the three detection branches are electrically connected to the three drive signal output terminals, respectively, the three detection output terminals of the three detection branches are electrically connected to the main control circuit, respectively, and are used to output a first detection signal, a second detection signal and a third detection signal to the main control circuit, so that the main control circuit obtains a phase of the three-phase drive signal and adjusts the control signal based on the first detection signal, the second detection signal and the third detection signal.

9. 9. The driving circuit of the portable fan of claim 8, wherein the detection branch includes a first detection resistor, a second detection resistor and a third detection resistor, the first detection resistor and the second detection resistor are connected in series, one end of the first detection resistor remote from the second detection resistor is the detection terminal, one end of the second detection resistor remote from the first detection resistor is grounded, and a node between the first detection resistor and the second detection resistor is the detection output terminal.

10. the three-phase driving circuit includes a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor, a sixth transistor, a seventh transistor, an eighth transistor and a ninth transistor, a first conduction terminal of the first transistor, the second transistor and the third transistor are all connected to a power supply terminal, a first conduction terminal of the fourth transistor is connected to the power supply terminal, a first conduction terminal of the fifth transistor is connected to the power supply terminal, a first conduction terminal of the sixth transistor is connected to the power supply terminal, control terminals of the fourth transistor, the fifth transistor and the sixth transistor are electrically connected to the main control circuit, respectively, control terminals of the seventh transistor, the eighth transistor and the seventh transistor are electrically connected to the control terminals of the fourth transistor, the fifth transistor and the sixth transistor, respectively, and are used for receiving the control signal, second conduction terminals of the fourth transistor, the fifth transistor and the sixth transistor are all grounded, a first conduction terminal of the seventh transistor is grounded to the second conduction terminal of the first transistor, a first conductive terminal of the seventh transistor connected to the second conductive terminal of the second transistor, the second conductive terminal of the seventh transistor being grounded, a first conductive terminal of the eighth transistor connected to the second conductive terminal of the second transistor, the second conductive terminal of the seventh transistor being grounded, a first conductive terminal of the ninth transistor connected to the second conductive terminal of the third transistor, the second conductive terminal of the ninth transistor being grounded, a node between the first conductive terminal of the seventh transistor and the second conductive terminal of the first transistor, a node between the first conductive terminal of the eighth transistor and the second conductive terminal of the second transistor, a node between the first conductive terminal of a ninth transistor and the second conductive terminal of the third transistor respectively function as the three driving signal output terminals, the at least three signal input terminals are three PWM signal input terminals, and the control signal includes three PWM signals; the driving circuit of the portable fan further includes a current detection circuit 15, and the second conductive terminals of the seventh transistor, the eighth transistor and the ninth transistor are all grounded via the current detection circuit, and the current detection circuit is electrically connected to the main control circuit; and the current detection circuit is9. The driving circuit of the portable fan according to claim 8, further comprising a sense resistor and a sense capacitor, the second conductive terminals of the seventh transistor, the eighth transistor and the ninth transistor are grounded via the sense resistor and the sense capacitor in order, and a node between the sense resistor and the sense capacitor is electrically connected to the main control circuit.

11. 9. The driving circuit of claim 8, wherein the three-phase driving circuit includes a first transistor, a second transistor, a third transistor, a fourth transistor, a fifth transistor and a sixth transistor, first conduction terminals of the first transistor, the second transistor and the third transistor are connected to a power supply terminal, a first conduction terminal of the fourth transistor is connected to a second conduction terminal of the first transistor, a first conduction terminal of the fifth transistor is connected to a second conduction terminal of the second transistor, a first conduction terminal of the sixth transistor is connected to a second conduction terminal of the third transistor, a node between the first conduction terminal of the fourth transistor and the second conduction terminal of the first transistor, a node between the first conduction terminal of the fifth transistor and the second conduction terminal of the second transistor, and a node between the first conduction terminal of the sixth transistor and the second conduction terminal of the third transistor are respectively used as three of the driving signal output terminals, and control terminals of the first transistor, the second transistor, the third transistor, the fourth transistor, the fifth transistor and the sixth transistor are respectively used to electrically connect to the main control circuit to receive the control signal, and the control signal includes six PWM signals.

12. 12. The driving circuit of the portable fan of claim 11, wherein the driving circuit of the portable fan further includes a current detection circuit, a second conductive terminal of the sixth transistor is grounded through the current detection circuit, the current detection circuit is electrically connected to the main control circuit, the current detection circuit includes a sense resistor and a sense capacitor, the second conductive terminal of the sixth transistor is grounded through the sense resistor, the sense capacitor is connected in parallel with the sense resistor, a node between the sense resistor and the second conductive terminal of the sixth transistor is electrically connected to the main control circuit, the current detection circuit also includes a first series resistor, a second series resistor and a parallel resistor, the parallel resistor is connected in parallel with the sense resistor, the first series resistor is connected between one end of the sense capacitor and one end of the sense resistor, and the second series resistor is connected between the other end of the sense capacitor and the other end of the sense resistor.

13. The main control circuit includes a main control chip and three three-phase control chips, each of the three-phase control chips is electrically connected to the main control chip and the three-phase driving circuit, the three-phase driving circuit includes a voltage conversion circuit, the voltage conversion circuit is used to receive a battery voltage, convert the battery voltage into a driving voltage, and supply the driving voltage to a power terminal of the three three-phase control chips, the main control chip is used to output a main control signal to the three three-phase control chips, so that the control signals are output by the three three-phase control chips to the three-phase driving circuit respectively, the driving circuit of the portable fan further includes a switch control circuit 21, the switch control circuit is electrically connected to the battery, the voltage conversion circuit and the main control circuit, and is used to control the operation of the voltage conversion circuit, the switch control circuit is connected to a button, a first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a fifth ...

13. The driving circuit of the portable fan of claim 12, further comprising a DC converter circuit, the DC converter circuit being used to receive the driving voltage and convert it into another DC operating voltage.

14. The driving circuit of the portable fan of claim 12, further comprising a DC converter circuit, the DC converter circuit being used to receive the driving voltage and convert it into another DC operating voltage.

15. The driving circuit of the portable fan of claim 12, further comprising a DC converter circuit, the DC converter circuit being used to receive the driving voltage and convert it into another DC operating voltage.

14. the driving circuit of the portable fan includes a battery voltage detection circuit, the battery voltage detection circuit includes a second voltage divider resistor and a third voltage divider resistor connected in series, a node between the second voltage divider resistor and the third voltage divider resistor is electrically connected to the main control circuit; or the battery voltage detection circuit includes a filter capacitor and a sampling resistor connected in series, the sampling resistor is connected between the filter capacitor and ground; the driving circuit of the portable fan further includes a signal amplification circuit, the node between the filter capacitor and the sampling resistor is connected to the main control circuit via the signal amplification circuit, the signal amplification circuit is used to amplify a signal at the node and provide the amplified signal to the main control circuit; The driving circuit of the portable fan further includes a Hall detection circuit, the Hall detection circuit is electrically connected to the main control circuit and is used for detecting a magnetic field generated by the DC brushless fan motor and outputting a Hall detection signal to the main control circuit, whereby the main control circuit obtains a rotor position of the DC brushless fan motor based on the Hall detection signal; the Hall detection circuit further includes a motor temperature detection element, the motor temperature detection element is connected between a Hall element of the Hall detection circuit and the main control circuit; the driving circuit of the portable fan further includes a transistor temperature detection circuit, the transistor temperature detection circuit detects a magnetic field generated by the DC brushless fan motor and outputs a Hall detection signal to the main control circuit, whereby the main control circuit obtains a rotor position of the DC brushless fan motor based on the Hall detection signal; the Hall detection circuit further includes a motor temperature detection element, the motor temperature detection element is connected between a Hall element of the Hall detection circuit and the main control circuit; 9. The portable fan driving circuit of claim 8, wherein the temperature detection circuit includes a first voltage dividing resistor and a thermistor connected in series, the thermistor is used to sense the temperature of each transistor of the three-phase driving circuit, and a node between the first voltage dividing resistor and the thermistor is electrically connected to the main control circuit and used to output a temperature signal, so that the main control circuit controls whether the driving circuit of the portable fan enters a temperature protection state according to the temperature signal, the thermistor is connected between the first voltage dividing resistor and ground, and the transistor temperature detection circuit includes a voltage stabilizing capacitor connected in parallel with the thermistor.

15. The driving circuit of the portable fan further includes the main control circuit, the main control circuit includes a main control chip and an auxiliary chip, the three-phase driving circuits, the back electromotive force detection circuit and the DC brushless fan motor are all two in number and are arranged in one-to-one correspondence, the main control chip is electrically connected to one of the three-phase driving circuits, thereby outputting the control signal to one of the three-phase driving circuits to drive the corresponding one of the DC brushless fan motors, the back electromotive force detection circuit is electrically connected to the corresponding one of the three-phase driving circuits, thereby outputting the corresponding first detection signal, the second detection signal and the third detection signal to the main control chip, thereby the main control chip controls one of the three-phase driving circuits.

9. The driving circuit of claim 8, wherein the auxiliary chip obtains a phase of the three-phase driving signal of one of the three-phase driving circuits to adjust the control signal output to the one of the three-phase driving circuits, the auxiliary chip is electrically connected to the other of the three-phase driving circuits, thereby outputting the control signal to the other of the three-phase driving circuits to drive the corresponding other of the DC brushless fan motors, and the other of the back electromotive force detection circuits is electrically connected to the corresponding three-phase driving circuits, thereby outputting the corresponding first detection signal, the second detection signal and the third detection signal to the auxiliary chip, whereby the auxiliary chip obtains a phase of the three-phase driving signal of the other of the three-phase driving circuits to adjust the control signal output to the other of the three-phase driving circuits.

16. A handheld fan comprising an inner shell, an outer shell and a fan assembly, the inner shell being formed with an air passage, an air inlet communicating with one side of the air passage, and an air outlet communicating with the other side of the air passage, at least a portion of the fan assembly being disposed in the air passage, the outer shell being used to cover and install the outside of the inner shell, the inner shell having a wiring opening, one side of the wiring opening facing an electrical connection of the fan assembly and the other side of the wiring opening facing an electrical connection of a handheld part of the handheld fan, the electrical connection of the fan assembly being electrically connected to the electrical connection of the handheld part via a conductor passing through the wiring opening.

17. the handheld portion has an attachment opening, the handheld portion is connected to the outer shell, the attachment opening faces the other side of the wiring opening, the handheld fan includes a mounting bracket disposed on the handheld portion, at least a portion of the mounting bracket disposed in the mounting opening, the mounting bracket connected to the inner shell, the mounting bracket having an accommodating space for passing the conductor; 17. The handheld fan of claim 16, wherein the electrical connection portion of the handheld portion includes a first circuit board, the first circuit board is disposed on a mounting bracket, and the first circuit board is plugged into the electrical connection portion of the fan assembly via the conductors.

18. the handheld fan includes a second circuit board and a range knob assembly, the second circuit board is disposed on the mounting bracket, the second circuit board is plugged into the first circuit board via the conductor, the range knob assembly is disposed on the mounting bracket, the range knob assembly is connected to the second circuit board, and the second circuit board and the first circuit board are disposed opposite each other; 18. The handheld fan of claim 17, further comprising a protective switch button assembly, the protective switch button assembly being disposed on the mounting bracket, and the protective switch button assembly being electrically connected to the first circuit board.

19. 18. The handheld fan of claim 17, further comprising a battery, the battery being disposed in the handheld portion, the battery being plugged into the first circuit board via the conductor.

20. 18. The handheld fan of claim 17, wherein a baffle is disposed on the inner shell, the inner shell and the baffle are surrounded to form a wiring groove, and a portion of the first circuit board is disposed in the wiring groove.

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