Power tool, lighting device, battery pack and charger

Abstract

The utility model discloses a power tool, a lighting device, a battery pack and a charger. The power tool comprises a circuit board assembly which is at least partially arranged in a shell; the circuit board assembly is connected with the motor to control the motor; the circuit board assembly comprises at least one heating part, and the heating part generates temperature rise when the power tool runs; the active heat dissipation assembly is configured to guide fluid flow by using vibration motion; the fluid faces a surface of the at least one heat generating portion to extract heat from the at least one heat generating portion.

Description

Technical Field

[0001] The present application relates to the field of power tools, and particularly relates to a power tool, a lighting device, a battery pack and a charger. Background Art

[0002] In the related art, whether it is the power tool itself (including DC power tools, AC power tools and pneumatic tools), the battery pack for charging DC tools and the charger for charging the battery pack, in order to achieve better control effects, a control unit with electronic components is provided. To ensure the reliable application of the electronic components, an over-temperature protection point is set, and when the temperature reaches the over-temperature protection point, a protection program is started.

[0003] Especially for the battery pack, there are also battery cells provided in the battery pack. To ensure the use safety, the thermal management of the battery cells of the battery pack also needs to set an over-temperature protection point, and when the temperature reaches the over-temperature protection point, a protection program is started.

[0004] Generally speaking, after the protection program is started, the output power and output power of the product will be affected, and if the heat dissipation is not good and the protection program is frequently entered, it will inevitably affect the application of the product.

[0005] This part provides background information related to the present application, and these background information are not necessarily prior art. Summary of the Utility Model

[0006] An object of the present application is to solve or at least alleviate part or all of the above problems. For this reason, an object of the present application is to provide a power tool, a lighting device, a battery pack and a charger.

[0007] To achieve the above object, the present application adopts the following technical solutions:

[0008] A power tool includes: a housing; an output part configured to output power; a motor, at least part of which is disposed in the housing; the motor drives the output part; a power supply that supplies power to at least the motor; a circuit board assembly, at least part of which is disposed in the housing; the circuit board assembly is connected to the motor to control the motor; the circuit board assembly includes at least one heating part, and the heating part generates a temperature rise when the power tool is running; an active heat dissipation assembly that dissipates heat from at least the circuit board assembly; the active heat dissipation assembly is configured to use vibrational motion to guide the flow of fluid so that the fluid flows through the surface of at least one heating part to extract heat from at least one heating part.

[0009] In some embodiments, the power of the circuit board assembly is greater than or equal to 2W; the maximum output power of the power tool is greater than or equal to 200W.

[0010] In some embodiments, the outer diameter of the motor is greater than or equal to 20 mm.

[0011] In some embodiments, the motor includes a drive shaft that rotates about a drive axis, and the drive shaft drives an output portion to output power to implement the functions of a power tool.

[0012] In some embodiments, a fan is further included. The fan is formed on or connected to the drive shaft, and the fan rotates to form an air path for dissipating heat inside the power tool.

[0013] In some embodiments, the housing includes at least one vent, and the vent allows fluid to flow between the inside and the outside environment of the power tool.

[0014] In some embodiments, the circuit board assembly includes a circuit board body, a heat-generating portion is disposed on the circuit board body, and an active heat dissipation component is connected to the circuit board body and makes thermal contact with the circuit board body.

[0015] In some embodiments, the active heat dissipation component is attached to a component of a non-heat-generating portion near the circuit board body.

[0016] In some embodiments, the active heat dissipation component is attached to the housing outside the circuit board body.

[0017] In some embodiments, the active heat dissipation component is disposed on the circuit board body.

[0018] In some embodiments, the active heat dissipation component does not contact the heat-generating portion.

[0019] In some embodiments, multiple active heat dissipation components are provided.

[0020] In some embodiments, the thickness of the active heat dissipation component does not exceed two millimeters.

[0021] In some embodiments, the active heat dissipation component includes a cooling element and a support structure for supporting the cooling element, and the cooling element is driven to cause a vibrational motion at a certain frequency.

[0022] In some embodiments, the active heat dissipation component further includes an orifice plate having one or more orifices, and the orifice plate is disposed between the cooling element and the surfaces of one or more heat-generating portions.

[0023] A lighting device, comprising: a lamp head assembly including a lighting lamp; a power supply for supplying power to at least the lamp head assembly; a support housing for supporting at least the lighting lamp; a circuit board assembly at least partially disposed in the support housing; the circuit board assembly being connected to the lamp head assembly to control the lighting lamp; the circuit board assembly including at least one heat-generating portion that generates a temperature rise during operation of the lamp head assembly; an active heat dissipation component for dissipating heat from at least one of the lighting lamp or the circuit board assembly; the active heat dissipation component being configured to use vibrational motion to direct fluid flow such that the fluid flows across the surface of at least one heat-generating portion or the lighting lamp to extract heat from at least one heat-generating portion or the lighting lamp.

[0024] A battery pack for providing electrical energy to a power tool; comprising: a battery pack housing, the battery pack housing at least includes a heating part that generates a temperature rise during the charging / discharging process of the battery pack; a power tool interface disposed on the battery pack housing and configured to be coupled to the power tool; an active heat dissipation assembly disposed in the battery pack housing; the active heat dissipation assembly is configured to use vibrational motion to guide fluid flow so that the fluid flows through the surface of at least one heating part to extract heat from at least one heating part.

[0025] In some embodiments, it further includes: a battery cell accommodated in the battery pack housing; the battery cell generates a temperature rise during the charging / discharging process of the battery pack, and the active heat dissipation assembly is disposed close to at least one battery cell.

[0026] In some embodiments, the battery cell provides electrical energy for the active heat dissipation assembly.

[0027] In some embodiments, it further includes a circuit board assembly, at least partially disposed in the battery pack housing; the circuit board assembly at least controls the discharge circuit; the circuit board assembly includes at least one heating part.

[0028] In some embodiments, the discharge circuit is electrically connected to the battery cell and the power tool interface respectively, and the discharge circuit is configured to transmit electrical energy to the power tool via the power tool interface, and the discharge circuit is disposed on the circuit board assembly.

[0029] In some embodiments, the active heat dissipation assembly is formed or connected to the circuit board assembly.

[0030] In some embodiments, the battery pack housing at least includes one vent, and the vent allows fluid to flow between the battery pack and the external environment.

[0031] In some embodiments, the battery pack provides a nominal voltage greater than or equal to 12V and less than or equal to 100V.

[0032] In some embodiments, the nominal voltage of each battery cell is greater than or equal to 3.6V, and the average discharge current of the battery pack is greater than or equal to 20 amperes (A).

[0033] In some embodiments, the capacity of each battery cell is greater than or equal to 1.5 ampere-hours (Ah).

[0034] A charger for charging a battery pack, comprising: a charger housing; a battery pack interface disposed on the charger housing, the battery pack interface configured to couple with the battery pack; a circuit board assembly, at least partially disposed in the housing; the circuit board assembly including at least one heating portion that generates a temperature rise when the charger charges the battery pack; an active heat dissipation assembly disposed within the charger housing; the active heat dissipation assembly configured to use vibrational motion to direct fluid flow such that the fluid flows across the surface of at least one heating portion to extract heat from at least one heating portion.

[0035] In some embodiments, the charger has a charging voltage of at least 12V.

[0036] In some embodiments, the charger has a charging power of at least 20 W.

[0037] In some embodiments, further comprising: a charging circuit configured to be electrically connected to the battery pack interface and charge the battery pack; the charging circuit including a switching element, the switching frequency of the switching element being greater than or equal to 20 kHz.

[0038] In some embodiments, the heating portion includes a power semiconductor device or a transformer.

[0039] In some embodiments, the charger housing includes at least one vent that allows fluid communication with the external environment of the charger.

[0040] In some embodiments, the charger housing includes a mounting structure for mounting the battery pack to a mounting position, the mounting structure including a locking portion for holding the battery pack in the charger and a guiding portion for guiding the mounting path of the battery pack.

[0041] In some embodiments, the circuit board assembly includes a circuit board body, the heating portion is disposed on the circuit board body, and the active heat dissipation assembly is connected to and in thermal contact with the circuit board body.

[0042] In some embodiments, the circuit board assembly includes a circuit board body, the heating portion is disposed on the circuit board body, the active heat dissipation assembly is disposed on the circuit board body, and the active heat dissipation assembly is disposed close to the heating portion. Description of the Drawings

[0043] Figure 1 is a structural diagram of the first embodiment in the present application;

[0044] Figure 2 is an exemplary diagram of a power tool, a lighting device, a battery pack, and a charger;

[0045] Figure 3 is Figure 1 a schematic diagram of a cross-sectional view of;

[0046] Figures 4a - 4cIt is a structural example diagram of an active heat dissipation component;

[0047] Figure 5 It is a structural example diagram of a circuit board component;

[0048] Figure 6 It is another example diagram of a circuit board component;

[0049] Figure 7 It is an electrical structure diagram of an embodiment of the present application;

[0050] Figures 8a - 8b It is a structure diagram of the second embodiment in the present application;

[0051] Figure 9 It is Figure 8a a decomposition diagram of;

[0052] Figure 10 It is a structure diagram of a charger and a battery pack of the third embodiment in the present application;

[0053] Figure 11 It is a structure diagram of the charger of the third embodiment in the present application;

[0054] Figure 12 It is a structure diagram of another charger of the third embodiment in the present application;

[0055] Figure 13 It is a structure diagram of another charger and another battery pack of the third embodiment in the present application. Detailed implementation manners

[0056] Before explaining any embodiment of the present application in detail, it should be understood that the present application is not limited to the structural details and component arrangements described in the following description or shown in the above drawings.

[0057] In the present application, the terms "comprising", "including", "having" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the phrase "comprising a..." does not exclude the presence of additional identical elements in the process, method, article or device comprising that element.

[0058] In the present application, the term "and / or" is a correlative relationship describing associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. Additionally, in the present application, the character " / " generally represents an "and / or" relationship between the associated objects before and after.

[0059] In this application, the terms "connected", "combined", "coupled", and "mounted" can be direct connections, combinations, couplings, or mountings, or indirect connections, combinations, couplings, or mountings. For example, a direct connection means that two parts or components are connected together without an intermediate member, and an indirect connection means that two parts or components are respectively connected to at least one intermediate member, and these two parts or components are connected through the intermediate member. In addition, "connected" and "coupled" are not limited to physical or mechanical connections or couplings, and can include electrical connections or couplings.

[0060] In this application, those of ordinary skill in the art will understand that relative terms used in combination with a quantity or condition (e.g., "about", "approximately", "substantially", etc.) include the recited value and have the meaning indicated by the context. For example, such relative terms include at least the degree of error associated with the measurement of a particular value, tolerances resulting from manufacturing, assembly, use, etc. associated with a particular value. Such terms should also be considered to disclose a range defined by the absolute values of two endpoints. Relative terms may refer to a plus or minus of a certain percentage (e.g., 1%, 5%, 10% or more) of the indicated value. Numerical values without the use of relative terms should also be disclosed as specific values with tolerances. In addition, when expressing a relative angular positional relationship (e.g., substantially parallel, substantially perpendicular), "substantially" may refer to a plus or minus a certain number of degrees (e.g., 1 degree, 5 degrees, 10 degrees or more) from the indicated angle.

[0061] In this application, those of ordinary skill in the art will understand that the functions performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, the functions performed by a part can also be performed by one part, one component, or a combination of multiple parts.

[0062] In this application, the directional terms such as "upper", "lower", "left", "right", "front", "rear", etc. are described based on the orientation and positional relationship shown in the drawings, and should not be construed as a limitation on the embodiments of this application. In addition, in the context, it should also be understood that when it is mentioned that one element is connected "above" or "below" another element, it can not only be directly connected "above" or "below" another element, but also be indirectly connected "above" or "below" another element through an intermediate element. It should also be understood that the directional terms such as upper side, lower side, left side, right side, front side, rear side, etc. not only represent the positive direction, but can also be understood as the side direction. For example, "below" can include directly below, lower left, lower right, front lower, and rear lower, etc.

[0063] In this application, the terms "controller", "processor", "central processing unit", "CPU", and "MCU" are interchangeable. When using the units "controller", "processor", "central processing unit", "CPU", or "MCU" to perform specific functions, unless otherwise specified, these functions can be performed by a single one of the above units or multiple ones of the above units.

[0064] In this application, for the purpose of implementing specific functions, the terms "device", "module", or "unit" can be implemented in the form of hardware or software.

[0065] In this application, the terms "calculate", "judge", "control", "determine", "identify", etc. refer to the operations and processes of a computer system or a similar electronic computing device (e.g., a controller, a processor, etc.).

[0066] As Figures 1 - 2 shown, a power tool, wherein the power tool includes an active heat dissipation component 20. In this embodiment, the power tool is an impact wrench 100. In some embodiments, it can also be other handheld tools, such as a screwdriver, an electric drill, a wrench, an impact drill, a rotary hammer, a nail gun, a sander, a reciprocating saw, a jigsaw, a circular saw, an angle grinder, an angle tool. In some embodiments, it can also be a garden tool, such as a lawn mower, a blower, a rear-walk electric tool such as a lawn mower, a chain saw, a cleaning machine, etc. In some embodiments, it can also be a bench tool, such as a table saw, a miter saw, etc. Or, the power tool can also be other power tools, such as a fan, an optoelectronic detection device, etc. Or a non-road-going walking device, such as a multi-purpose vehicle, can also be an ATV (All-Terrain Vehicle), a UTV (Utility Task Vehicle), a golf cart, an all-terrain vehicle (ATV), and can also be an agricultural machinery vehicle, such as a harvester, a spraying vehicle, etc.

[0067] As Figures 1 to 7 shown, taking the impact wrench 100 as an example. The impact wrench 100 includes a power supply 30. Among them, in this embodiment, the power supply 30 is a DC power supply. The DC power supply is used to supply electrical energy to the impact wrench 100. The DC power supply is a battery pack, and the battery pack cooperates with a corresponding power circuit to supply power to the impact wrench 100. Those skilled in the art should understand that the power supply 30 is not limited to the scenario of using a DC power supply, and can also supply power to the corresponding components inside the machine through the mains power, an AC power supply, and cooperate with corresponding rectification, filtering, and voltage regulation circuits. In the following description, the battery pack 30 will be used to replace the power supply, but this should not be regarded as a limitation to the present invention.

[0068] The impact wrench 100 includes a housing 11, a motor 12, an output part 13, and a circuit board assembly 17. Among them, the motor 12 includes a drive shaft 121 that rotates about a first axis 101. In this embodiment, the motor 12 is specifically configured as an electric motor, and hereinafter, the electric motor 12 will be used instead of the motor, and the electric motor shaft 121 will be used instead of the drive shaft, but this does not limit the present application.

[0069] The housing 11 includes a motor housing 111 for accommodating the electric motor and an output housing 112 for accommodating at least part of the output part 13. The output housing 112 is connected to the front end of the motor housing 111. In this embodiment, the outer shell also forms or is connected with a grip part for the user to operate, which is convenient for the user to hold and operate. One end of the grip part is connected with a battery pack.

[0070] The output part 13 is used to drive a functional element to realize the function of a power tool. In this embodiment, the output part 13 includes an output shaft 131. In some embodiments, a transmission assembly 14 is connected between the output part 13 and the motor 12. For example, tools with high-speed and high-torque output such as screwdrivers, drills, and saws. The output power of the motor 12 is transmitted to the output part 13 through the transmission assembly 14, and the output part 13 drives the functional element to complete the processing of the workpiece. In some embodiments, the motor 12 directly drives the output part 13, such as fans, hair dryers, lawn mowing tools, cleaning tools, etc., and the output part 13 drives the functional element (such as a fan blade, a blower, a cutting piece, or a water gun) to complete the processing or treatment of the workpiece.

[0071] The circuit board assembly 17 is connected to the motor 12 to control the operation of the motor 12. It can be understood that the connection between the circuit board assembly 17 and the motor 12 includes both the electrical connection between the circuit board assembly 17 and the motor 12 and the communication connection between the circuit board assembly 17 and the motor 12. The communication connection is, for example, through a digital signal connection, through an analog signal connection, or through a wireless signal connection. In this embodiment, the circuit board assembly 17 includes at least one heating part 17a, and the heating part 17a will generate a temperature rise when the impact wrench 100 is running.

[0072] The housing 11 forms a receiving space, and the motor 12 and the circuit board assembly 17 are at least partially arranged in the housing 11. In the related art, at least one fan 123 is arranged in the housing 11 for dissipating heat from the motor 12 and the circuit board assembly 17. In some embodiments, the fan 123 is formed or connected to the electric motor shaft 121, and when the motor 12 starts to work, the fan 123 also rotates in a certain preset rule. A wind path for dissipating heat inside the housing 11 is formed by the rotation of the fan 123. However, due to the increasing requirements for the output performance of power tools, the requirements for equipment heat dissipation are also increasing. In some embodiments, the distance between the fan 123 and the circuit board assembly 17 is relatively far, for example Figure 3As shown, the motor 12 and the fan 123 are disposed in the motor housing 111, and the circuit board assembly 17 is disposed at the position where the holding portion 113 is connected to the battery pack 30. A plurality of wires 124 are provided to connect the motor 12 and the circuit board assembly 17, which to a certain extent blocks the cooling effect of the heat dissipation air path generated by the fan 123 on the circuit board assembly 17.

[0073] In the solution of using the fan 123 for heat dissipation, generally when improving the heat dissipation effect, the number of fans 123 will be increased, the rotation speed of the fan 123 will be increased, or the size of the fan 123 will be increased, etc. These will cause problems such as noise of the fan 123, increase in product volume, and higher loss of the motor 12.

[0074] In the related art, there are also some components that increase heat sinks such as heat sinks, heat pipes, or vapor chambers in the circuit board assembly 17 to transfer heat. Although the heat sink reduces the temperature rise at the hot spots to a certain extent, it may not be able to fully solve the heat generated in current and future devices. Similarly, the heat pipes or vapor chambers may not provide enough heat to remove the excessive heat generated.

[0075] In this embodiment, an active heat dissipation component 20 is provided to dissipate heat from the circuit board assembly 17. The active heat dissipation component 20 is formed or connected to the circuit board assembly 17. The active heat dissipation component 20 is configured to use vibrational motion to guide fluid flow, and the fluid is directed towards the surface of at least one heat generating portion 17a to extract heat from at least one heat generating portion 17a.

[0076] As Figures 4a to 4c shown, the active heat dissipation component 20 includes a top plate 24 having an air outlet 241 therein, a cooling element 21, an orifice plate 23 having an orifice 231 therein, and a support structure 22.

[0077] The active heat dissipation component 20 includes a cooling element 21 that is in fluid communication and is configured to use vibrational motion to guide fluid towards the surface of one or more heat generating portions 17a. Heat is transferred from the heat generating portion 17a to the fluid. Here, the vibration includes reciprocating motion in one direction, including co-directional motion and opposite-phase motion at both ends.

[0078] The heat dissipation system constituted by the active heat dissipation component 20 is configured such that the fluid follows a path from the surface of one or more heat generating portions 17a through a structure whose temperature is lower than the surface of the heat generating portion 17a. This structure absorbs heat from the fluid. This structure is within the system and away from the active heat dissipation component 20.

[0079] The heat dissipation system may include at least one vent 114, 115 that allows for fluid communication with the external environment. Thus, the heat dissipation system can be an open system. The heat dissipation system is configured such that fluid follows a path from the surface of one or more heat generating parts 17a through the structure and exits the system through one or more vents to the external environment. For example, the system may include an air inlet 114 and an air outlet 115. Fluid can enter through the air inlet 114, travel to the active heat dissipation component 20 and be driven towards the surface of the heat generating part 17a. The fluid thus follows a path from the surface of one or more heat generating parts 17a through the structure and through the air outlet 115.

[0080] The cooling element 21 of the active heat dissipation component 20 includes a first side and a second side. The first side is distal to one or more heat generating parts 17a and is in fluid communication. The second side is adjacent to one or more heat generating parts 17a. The cooling element 21 is configured to use vibrational motion to direct fluid from the first side to the second side such that the fluid is driven towards the surface of one or more heat generating parts 17a.

[0081] In some embodiments, the active heat dissipation component 20 further includes a support structure 22. The cooling element 21 is supported by the support structure 22. The cooling element 21 is supported by the support structure 22 in the central region of the active heat dissipation component 20.

[0082] The active cooling system may also include an orifice plate 23 having one or more orifices 231 therein. The orifice plate 23 is disposed between the cooling element 21 and the surface of one or more heat generating parts 17a. The cooling element 21 is actuated or driven to drive fluid through one or more orifices 231. The fluid flows from one or more orifices 231 towards the surface of one or more heat generating parts 17a.

[0083] In some embodiments, the tip of the cooling element 21 includes a portion of the perimeter that is furthest from the support structure 22 and experiences the greatest deflection during actuation of the cooling element 21.

[0084] Figure 4a The active heat dissipation component 20 is depicted in an intermediate position. Thus, the cooling element 21 is shown as being substantially flat. For in-phase operation, the cooling element 21 is driven to Figure 4b and 4cvibrate between the positions shown. This vibratory motion draws fluid (such as air) into the air inlet 241 at a high speed and / or flow rate and discharges it through the discharge orifice 231. For example, the speed at which the fluid impinges on the heat generating portion 17a can be at least thirty meters per second. In some embodiments, the fluid is driven towards the heat generating portion 17a by the cooling element 21 at a speed of at least forty-five meters per second. In some embodiments, the fluid is driven towards the heat generating portion 17a by the cooling element 21 at a speed of at least sixty meters per second. In some embodiments, other speeds are possible. The active heat dissipation assembly 20 is also configured such that little or no fluid is drawn back through the orifice 132 by the vibratory motion of the cooling element 21.

[0085] In some embodiments, the thickness H of the active heat dissipation assembly 20 does not exceed two millimeters.

[0086] In some embodiments, the active heat dissipation assembly 20 can be a cooling system of a microelectromechanical system (MEMS). The system includes a plurality of cooling units. Each cooling unit includes a cooling element 21 in fluid communication. The active heat dissipation assembly 20 includes an orifice plate 23 having one or more orifices therein. The orifice plate 23 is disposed between the cooling element 21 and the surface of one or more heat generating portions 17a. The cooling element 21 is actuated or activated to drive fluid through one or more orifices. The fluid flows from one or more orifices towards the surface of one or more heat generating portions 17a. The cooling element 21 of the active heat dissipation assembly 20 is driven to cause a vibratory motion at a certain frequency. The cooling element 21 is in fluid communication and configured to use the vibratory motion to direct fluid towards the surface of one or more heat generating structures to extract heat from one or more heat generating portions 17a. The method further includes directing the fluid along a path from the surface of one or more heat generating structures through a structure having a temperature lower than the surface of the heat generating portion 17a. The structure is within the system, away from the active cooling system and absorbs heat from the fluid. In some embodiments, the fluid is directed to flow along a path from the surface of one or more heat generating portions 17a through a component and return to the active heat dissipation assembly 20. In some embodiments, the fluid is directed to flow along a path from the surface of at least one heat generating portion 17a through a component and leave the system through at least one vent to the external environment.

[0087] The thickness H of the active heat dissipation assembly 20 can be less than 2 millimeters. In some embodiments, the thickness H of the active heat dissipation assembly 20 does not exceed 1.5 millimeters. In some embodiments, the thickness H does not exceed 1.1 millimeters. In some embodiments, the thickness H does not exceed one millimeter. In some embodiments, the thickness H does not exceed two hundred and fifty micrometers. In some embodiments, the distance y between the bottom of the orifice plate 23 and the top of the heat generating portion 17a can be small. In some embodiments, y is at least two hundred micrometers and does not exceed one millimeter. In some embodiments, y is at least two hundred micrometers and does not exceed three hundred micrometers.

[0088] Although one active heat dissipation component 20 (such as a cooling unit) is shown, multiple active heat dissipation components 20 can be used in combination with the heat generating part 17a. For example, a one-dimensional or two-dimensional array of cooling units can be utilized. The cooling element 21 has a first side away from the heat generating part 17a and a second side close to the heat generating part 17a. The first side of the cooling element 21 is the top of the cooling element 21 (closer to the top plate) and the second side is the bottom of the cooling element 21 (closer to the orifice plate 23). The cooling element 21 is actuated to perform a vibrating motion. The vibrating motion of the cooling element 21 drives fluid from the first side of the cooling element 21 away from the heat generating part 17a to the second side of the cooling element 21 close to the heat generating part 17a.

[0089] In some embodiments, piezoelectricity is used to actuate the cooling element 21. Thus, the cooling element 21 can be a piezoelectric cooling element 21. The cooling element 21 can be driven by a piezoelectric mounted on or integrated into the cooling element 21. In some embodiments, the cooling element 21 is driven in another way, including but not limited to providing piezoelectricity on another structure in the active heat dissipation component 20. The cooling element 21 and similar cooling elements 21 are hereinafter referred to as piezoelectric cooling elements 21, although mechanisms other than piezoelectricity can be used to drive the cooling element 21. In some embodiments, the cooling element 211 includes a piezoelectric layer on a substrate. The substrate can be a stainless steel, nickel alloy, and / or Hastelloy substrate. In some embodiments, the piezoelectric layer includes multiple sub-layers formed as a thin film on the substrate. In other embodiments, the piezoelectric layer can be a bulk layer fixed to the substrate. Such a piezoelectric cooling element 21 also includes an electrode for activating the piezoelectric element. In some embodiments, the substrate serves as the electrode. In other embodiments, a bottom electrode can be provided between the substrate and the piezoelectric layer.

[0090] As Figures 5 to 7As shown, in this embodiment, the motor 12 includes a stator winding and a rotor. In some embodiments, the motor 12 is a three-phase brushless motor 12, including a rotor with permanent magnets and a three-phase stator winding U, V, W that is commutated electronically. In some embodiments, the three-phase stator windings U, V, W are connected in a star configuration, and in other embodiments, the three-phase stator windings U, V, W are connected in a delta configuration. However, it must be understood that other types of brushless motors are also within the scope of this disclosure. The brushless motor may include fewer or more than three phases. In this embodiment, the nominal voltage of the motor 12 is greater than or equal to 12V. In some embodiments, the nominal voltage of the motor 12 is greater than or equal to 12V and less than or equal to 60V. In some embodiments, the nominal voltage of the motor 12 is greater than or equal to 3V and less than or equal to 60V. In some embodiments, the nominal voltage of the motor 12 is greater than or equal to 14V and less than or equal to 80V. In some embodiments, the nominal voltage of the motor 12 is greater than or equal to 20V and less than or equal to 80V. In this embodiment, the outer diameter of the motor 12 is greater than or equal to 20mm. In some embodiments, the outer diameter of the motor 12 is greater than or equal to 30mm. In some embodiments, the outer diameter of the motor 12 is greater than or equal to 30mm and less than or equal to 100mm.

[0091] The circuit board assembly 17 includes: a printed circuit board (PCB) and a flexible printed circuit (FPC). The circuit board assembly 17 includes a circuit board body 171. In this embodiment, the circuit board body 171 is a substrate, for example, a copper-clad laminate, a ceramic board, and an enamel-coated steel substrate. The circuit board assembly 17 further includes a plurality of electronic components disposed on the circuit board body 171. At least some of the electronic components are heat-generating parts 17a. The electronic components include: a controller 172 and a switching circuit 173. Among them, the switching circuit 173 is electrically connected to the stator windings U, V, W of the motor 12, and is used to transfer the current from a power supply such as the battery pack 30 to the stator windings U, V, W to drive the motor 12 to rotate. In one embodiment, the switching circuit 173 includes a plurality of switching elements Q1, Q2, Q3, Q4, Q5, Q6. The gate terminal of each switching element is electrically connected to the controller 172 for receiving a control signal from the controller 172. The drain or source of each switching element is connected to the stator windings U, V, W of the motor 12. The switching elements Q1-Q6 receive control signals from the controller 172 to change their respective conduction states, thereby changing the current applied to the stator windings U, V, W of the motor 12 from a power supply such as the battery pack 30. In one embodiment, the switching circuit 173 can be a three-phase bridge driver circuit including six controllable semiconductor power devices (such as field effect transistors (FETs), bipolar junction transistors (BJTs), insulated gate bipolar transistors (IGBTs), etc.). It can be understood that the above-mentioned switching elements can also be any other type of solid-state switch, such as IGBTs, BJTs, etc.

[0092] The controller 172 is used to control the motor 12. The controller 172 employs a dedicated control chip, for example, a single-chip microcomputer, a microcontroller unit (MCU). Specifically, the controller 172 controls the conduction or cutoff states of the switching elements in the switching circuit 173 through the control chip. In some embodiments, the controller 172 controls the ratio between the conduction time and the cutoff time of the driving switch based on a pulse width modulation (PWM) signal. It should be noted that the control chip can be integrated within the controller 172, or can also be disposed independently of the controller 172. As for the structural relationship between the control chip and the controller 172, this embodiment does not limit it.

[0093] In some embodiments, the heating part 17a further includes: a resistor, a capacitor, a semiconductor device, and other electronic components disposed on the circuit board body 171.

[0094] In this embodiment, the power of the circuit board assembly 17 is greater than or equal to 2W. In some embodiments, the power of the heating part 17a in the circuit board assembly 17 is greater than or equal to 2W. In some embodiments, the power of the circuit board assembly 17 is greater than or equal to 3W.

[0095] The output power of the impact wrench 100 is greater than or equal to 200W. In some embodiments, the output power of the impact wrench 100 is greater than or equal to 300W. In some embodiments, the output power of the impact wrench 100 is greater than or equal to 400W.

[0096] As an implementation manner of this embodiment, the active heat dissipation component 20 is connected to the circuit board body 171 and is in thermal contact with the circuit board body 171. As an embodiment, the active heat dissipation component 20 is close to one side of the circuit board body 171. The cooling element 21 in the active heat dissipation component 20 does not actually contact the circuit board body 171. In this embodiment, the active heat dissipation component 20 is attached to a component of the non-heating part near the circuit board body 171. For example, the active heat dissipation component 20 can be attached to the housing 11 near the circuit board body 171. The heat generated by the heating part 17a is transferred to the circuit board body 171, and a jet channel formed between the ventilation openings 114, 115 on the housing 11 and the circuit board body 171 corresponds to the circuit board body 171 and / or other heating parts 17a on the circuit board assembly 17, so as to maintain and allow fluid flow.

[0097] As Figure 6 described, as an alternative embodiment, the active heat dissipation component 20 is disposed on the circuit board body 171 and is in actual contact with the circuit board body 171. Optionally, multiple active heat dissipation components 20 are provided or are provided in accordance with the number of heating parts 17a. The active heat dissipation component 20 is disposed at a position close to the heating part 17a. The active heat dissipation component 20 does not contact the heating part 17a. In this embodiment, the active heat dissipation component 20 is attached near the heating part 17a. For example, a support frame is provided to support the cooling element 21. The fluid driven by the active heat dissipation component 20 directly dissipates heat from the heating part 17a. Optionally, the fluid driven by the active heat dissipation component 20 directly flows through the heating part 17a. The jet channel formed between the ventilation openings 114, 115 on the housing 11 and the heating part 17a corresponds to the heating part 17a, so as to maintain and allow fluid flow.

[0098] In this embodiment, the housing 11 includes at least one vent, and the vents 114, 115 allow fluid communication with the external environment of the power tool. In this embodiment, the vent 114 operates as an air inlet, and the vent 115 operates as an air outlet.

[0099] Cooler fluid (such as air) near the active heat dissipation component 20 is drawn towards one or more cooling elements 21. Optionally, the fluid from the air inlet 114 moves towards one or more cooling elements 21. One or more cooling elements 21 drive the fluid to move from a side away from the circuit board body 171 or the heat generating part 17a to a side close to the circuit board body 171 or the heat generating part 17a. Thus, the fluid is driven into contact with the circuit board body 171 or the heat generating part 17a. The heat of the circuit board body 171 or the heat generating part 17a is transferred to the fluid. The fluid flows along the circuit board body 171 or the heat generating part 17a and leaves the area near the circuit board body 171 or the heat generating part 17a, taking away the heat from the circuit board body 171 or the heat generating part 17a. Therefore, the fluid carrying heat from the circuit board body 171 or the heat generating part 17a can be discharged from inside the impact wrench 100, and cooler fluid is drawn in through the air inlet 114 from the external environment to cool the heat generating part 17a. In addition, since the fluid is guided to the air outlet 115 away from one or more cooling elements 21, during this process, the heat can be transferred to one or more structures along a preset path and dissipated by them. For example, the temperature may be lower than that of the heat generating part 17a and / or lower than that of the fluid carrying the heat from the heat generating part 17a. For example, the heat can be transferred to the housing 11. Therefore, the fluid can be at least slightly cooled before leaving the impact wrench 100. In some embodiments, the fluid passes through a sufficient number or configuration of one or more low-temperature structures and / or a sufficient distance such that at least ninety percent of the heat is removed from the fluid. In some embodiments, the fluid passes through a sufficient number and / or configuration of one or more low-temperature structures and / or a sufficient distance such that at least eighty percent of the heat is removed from the fluid. In some embodiments, the fluid passes through a sufficient number and / or configuration of one or more low-temperature structures and / or a sufficient distance such that at least fifty percent of the heat is removed from the fluid. Other amounts of heat can be dissipated in other embodiments. In some embodiments, the impact wrench 100 further includes grooves or guides in the pipes and / or the housing for guiding the fluid flow. In some embodiments, the path of the fluid may include a heat sink or other mechanisms for heat dissipation. For example, a metal plate is provided inside the housing 11 for heat dissipation. Therefore, heat can be effectively removed from the impact wrench 100.

[0100] As Figure 2As shown, as an alternative embodiment, the power tool is a lighting device 50. The output unit 53 is a non-motor-driven functional element, and the functional element is, for example, a light emitter, including a lighting light emitter, a laser, etc. The lighting device 50 is not provided with a motor. The lighting device 50 includes a circuit board assembly for controlling the lighting light emitter. The lighting device 50 further includes a battery pack 30 for supplying power to it.

[0101] As Figure 2 , Figures 8a to 9 described, as the second embodiment of the present application, it relates to a battery pack 30. The battery pack 30 supplies power to the above-mentioned power tools (including tools with motors and lighting devices). Among them, the power tool includes an output unit 13. In this embodiment, the power tool is the same as or similar to the first embodiment, and the detailed description is omitted here for the purpose of simplicity of the specification.

[0102] The battery pack 30 provides a nominal voltage greater than or equal to 10V and less than or equal to 80V. The battery pack 30 includes: a battery pack housing 31 and a power tool interface 32. Among them, the power tool interface 32 is provided on the battery pack housing 31, and the power tool interface 32 is configured to be coupled to the power tool. When the battery pack 30 is attached to the power tool, the power tool interface 32 is coupled to the terminal block (not shown) of the power tool. The battery pack 30 provides a discharge current to the power tool through the power tool interface 32. As Figure 8b shown, the battery pack 30B is a high-capacity high-voltage battery pack. Optionally, the nominal voltage of the battery pack 30B can be greater than or equal to 20V and less than or equal to 100V. For example, the nominal voltage of the battery pack can be 24V, 40V, 56V, 80V, etc. The average discharge current of the battery pack is greater than or equal to 20 amperes (A).

[0103] In this embodiment, the battery pack housing 31 at least includes a heat-generating part that generates temperature rise during the charging / discharging process of the battery pack 30. For easy distinction, the heat-generating part here is the second heat-generating part.

[0104] The active heat dissipation assembly 20 is arranged in the battery pack housing 31. The active heat dissipation assembly 20 is configured to use vibrational motion to guide fluid flow, and the fluid faces the surface of the at least one second heat-generating part to extract heat from the at least one second heat-generating part.

[0105] Among them, the working principle of the active heat dissipation assembly 20 is basically the same as that of the active heat dissipation assembly in the first embodiment. Its specific structure and size are appropriately adjusted according to the differences between the battery pack 30 and the power tool.

[0106] In this embodiment, the second heating part includes the battery cell 33. The battery cell 33 is accommodated in the battery pack housing 31. The battery cell 33 generates temperature rise during the charging / discharging process of the battery pack 30, and the active heat dissipation component 20 is disposed close to at least one battery cell 33. In this embodiment, the battery cell 33 provides electrical energy for the active heat dissipation component 20.

[0107] In some embodiments, the battery pack 30 is configured as 5S3P, that is, a group of 5 series-connected battery cells 33, with 3 groups in parallel. The battery pack housing 31 surrounds the battery cells 33. In some embodiments, as Figure 9 shown, the battery pack 30 is configured as 5S2P, that is, a group of 5 series-connected battery cells 33, with 2 groups in parallel. In other embodiments, other combinations of the battery cells 33 in the battery pack 30 are also possible. The nominal voltage of each battery cell 33 is greater than or equal to 3V. In some embodiments, the nominal voltage of the battery cell 33 is greater than or equal to 3.6V. The nominal capacity of each battery cell 33 is greater than or equal to 1.5 ampere-hours (Ah). In some embodiments, the nominal capacity of each battery cell 33 is greater than or equal to 3 ampere-hours (Ah).

[0108] The battery cell 33 can be any rechargeable battery cell chemical type, such as lithium (Li), lithium-ion (Li-ion), other lithium-based chemicals, nickel-cadmium (NiCd), nickel-metal hydride (NiMH), etc.

[0109] In some embodiments, the battery pack 30 further includes a circuit board assembly. For the convenience of distinction, the second circuit board assembly 37 is used for reference. The second circuit board assembly 37 is at least partially disposed in the battery pack housing 31. The second circuit board assembly 37 is used to control the discharge circuit. Among them, the discharge circuit is electrically connected to the battery cell 33 and the power tool interface 32 respectively, and the discharge circuit is configured to transmit electrical energy to the power tool via the power tool interface 32. The discharge circuit is disposed on the second circuit board assembly 37.

[0110] At least some of the components on the second circuit board assembly 37 belong to the second heat generating part. The second circuit board assembly 37 includes a circuit board body 171. In this embodiment, the circuit board body 171 is a substrate, for example, a copper-clad laminate, a ceramic board, and an enamel-coated steel substrate. The circuit board assembly 17 also includes a plurality of electronic components disposed on the circuit board body 171. At least some of the electronic components are the second heat generating part. The second heat generating part includes a single-chip microcomputer, a microcontroller unit (MCU), a controllable semiconductor power device, a field effect transistor (FET), a bipolar junction transistor (BJT), an insulated gate bipolar transistor (IGBT), a resistor, a capacitor, and other semiconductor devices.

[0111] In this embodiment, the battery pack housing 31 includes at least one vent 311, 312, and the vent allows fluid to flow between the fluid of the power tool and the external environment.

[0112] As an implementation manner of this embodiment, taking the battery cell 37 as an example of the second heat generating part, the active heat dissipation component 20 is connected to the battery cell 37 and is in thermal contact with the battery cell 37. As an embodiment, the active heat dissipation component 20 is close to one side of the battery cell 37. The cooling element 21 in the active heat dissipation component 20 does not actually contact the battery cell 37. In this embodiment, the active heat dissipation component 20 is attached near the battery cell 37. For example, the active heat dissipation component 20 can be attached to the battery pack housing 31 near the battery cell 37. The heat generated by the battery cell 37 forms a jet channel between the vents 311, 312 on the battery pack housing 31 and the battery cell 37, and the jet channel corresponds to the battery cell 37 so that fluid flow can be maintained and allowed.

[0113] As an alternative embodiment, the active heat dissipation component 20 is disposed on the battery cell 37 and is in actual contact with the battery cell 37. As Figure 9 shown, the active heat dissipation component 20 is attached to the surface of the battery cell 37. Optionally, multiple active heat dissipation components 20 are provided or are provided in accordance with the number of battery cells 37.

[0114] As a second implementation manner of this embodiment, taking the circuit board assembly as an example of the second heat generating part, the setting manner of the active heat dissipation component 20 and the circuit board assembly refers to the disclosure as Figure 5 and Figure 6 disclosed.

[0115] Vents 311 and 312 are provided on the battery pack housing 31. In this embodiment, the vent 311 operates as an air inlet, and the vent 312 operates as an air outlet.

[0116] As Figures 10 to 13 described, as the third embodiment of the present application, it relates to a charger 400. The charger 400 is used to charge the battery pack 30. The charger 400 includes: a charger housing 41, a battery pack interface 42, and a circuit board assembly 44. Among them, the battery pack interface 42 is disposed on the charger housing 41. The battery pack interface 42 is used to couple with the battery pack 30. The circuit board assembly 44 is at least partially disposed in the charger housing 41. The circuit board assembly 44 includes at least one heating part, and the heating part generates a temperature rise when the charger 400 charges the battery pack 30. Among them, for the convenience of reference, this circuit board assembly 44 is the third circuit board assembly 44, and this heating part is the third heating part. In this embodiment, the charger 400 further includes a power interface 43, and the power interface 43 is used to access a power source. In this embodiment, the power source can be selected as an AC power source, and the power interface 43 can access 120V or 220V AC mains. The power interface 43 is connected with a power conversion circuit to convert the accessed alternating current into charging electric energy suitable for charging the battery pack 30 and auxiliary electric energy for supplying power to internal components of the charger 400. It can be understood that the power conversion circuit can at least include an AC / DC module. In an alternative implementation, the power interface 43 can access a photovoltaic panel, and the power conversion circuit can convert light energy into charging electric energy suitable for charging the battery pack 30 and auxiliary electric energy for supplying power to internal components of the charger 400. It can be understood that the power conversion circuit can include an MPPT (Maximum Power Point Tracking, solar controller 172) module, that is, a module that converts light energy into electric energy. In this embodiment, the charger housing 41 is connected with a power cord plug as the power interface 43. In an alternative implementation, the power interface 43 can also be other forms of interfaces, which are not limited herein.

[0117] As Figure 12 shown, the nominal voltage of the battery pack 30B can be greater than or equal to 20V and less than or equal to 100V. For example, the nominal voltage of the battery pack 30B can be 24V, 40V, 56V, 80V, etc. The charger 400B charges the battery pack 30B.

[0118] As Figure 13 shown, the charger 400C includes a plurality of battery pack interfaces 42C. That is to say, the charger 400c can charge a plurality of battery packs 30 simultaneously.

[0119] In this embodiment, it further includes an active heat dissipation component 20, which is disposed inside the charger housing 41. The active heat dissipation component 20 is configured to use vibrational motion to guide fluid flow, and the fluid faces the surface of the at least one third heating part to extract heat from the at least one third heating part.

[0120] The third circuit board assembly 44 includes a circuit board body. In this embodiment, the circuit board body is a substrate, for example, a copper-clad laminate, a ceramic board, and an enamel-coated steel substrate. The circuit board assembly 44 further includes a plurality of electronic components disposed on the circuit board body. At least some of the electronic components are the third heat-generating parts.

[0121] As an implementation manner of this embodiment, the active heat dissipation assembly 20 is connected to and in thermal contact with the circuit board body 171. As an alternative embodiment, the active heat dissipation assembly 20 is disposed on the circuit board body.

[0122] In this embodiment, the charger 400 has a charging voltage of at least 12V. In some embodiments, the charger 400 has a charging voltage between at least 12V and 100V. In some embodiments, the charger 400 has a charging power of at least 20W.

[0123] In this embodiment, the third circuit board assembly 44 is used to control the charging circuit. Among them, the charging circuit is configured to be electrically connected to the battery pack interface 42 and charge the battery pack 30. The charging circuit is disposed on the third circuit board assembly 44. The charging circuit includes a switching element, and the switching frequency of the switching element is greater than or equal to 20 kilohertz (kHz). In some embodiments, the switching frequency of the switching element is greater than or equal to 100 kilohertz (kHz). The switching circuit 173 can be a three-phase bridge driver circuit including six controllable semiconductor power devices (such as Field Effect Transistor (FET), Bipolar Junction Transistor (BJT), Insulated Gate Bipolar Transistor (IGBT), etc.). It can be understood that the above switching element can also be any other type of solid-state switch, such as IGBT, BJT, etc.

[0124] In some embodiments, the third heat-generating part further includes a resistor, a capacitor, and a transformer. Optionally, the power conversion circuit is a kind of transformer.

[0125] In some embodiments, the charger housing 41 includes an installation structure capable of installing the battery pack 30 to the installation position. The installation structure includes a locking portion 441 that holds the battery pack 30 in the charger 400 and a guiding portion 442 that guides the installation path of the battery pack 30.

[0126] The above shows and describes the basic principles, main features, and advantages of the present application. Those skilled in the art should understand that the above embodiments do not limit the present application in any form. Any technical solutions obtained by using equivalent replacements or equivalent transformations fall within the protection scope of the present application.

Claims

1. A power tool, characterized in that, Comprising: A housing; An output part configured to output power; A motor, at least partially disposed in the housing; The motor drives the output part; A power supply for supplying power to at least the motor; A circuit board assembly, at least partially disposed in the housing; the circuit board assembly is connected to the motor to control the motor; the circuit board assembly includes at least one heating part, and the heating part generates a temperature rise during the operation of the power tool; An active heat dissipation assembly for dissipating heat from at least the circuit board assembly; the active heat dissipation assembly is configured to use vibrational motion to guide fluid flow so that the fluid flows through the surface of at least one of the heating parts to extract heat from at least one of the heating parts.

2. The power tool according to claim 1, characterized in that, The power of the circuit board assembly is greater than or equal to 2W; the maximum output power of the power tool is greater than or equal to 200W.

3. The power tool according to claim 1, wherein, The motor includes a drive shaft that rotates about a drive axis, and the drive shaft drives the output part to output power to achieve the function of the power tool; it further includes a fan, the fan is formed or connected to the drive shaft, and the fan rotates to form an air path for dissipating heat inside the power tool.

4. The power tool according to claim 1, wherein The housing includes at least one ventilation opening, and the ventilation opening allows fluid communication between the fluid and the external environment of the power tool.

5. The power tool according to claim 1, characterized in that, The circuit board assembly includes a circuit board body, the heating part is disposed on the circuit board body, and the active heat dissipation assembly is connected to and in thermal contact with the circuit board body.

6. The power tool according to claim 5, characterized in that, The active heat dissipation assembly is attached to a component of a non-heating part near the circuit board body.

7. The power tool according to claim 6, characterized in that, The active heat dissipation assembly is attached to the housing outside the circuit board body.

8. The power tool according to claim 7, characterized in that, The active heat dissipation assembly is disposed on the circuit board body.

9. The power tool according to claim 8, wherein, The active heat dissipation assembly does not contact the heating part.

10. The power tool according to claim 1, characterized in that, The thickness of the active heat dissipation assembly does not exceed two millimeters.

11. The power tool according to claim 1, characterized in that, The active heat dissipation assembly includes a cooling element and a support structure for supporting the cooling element, and the cooling element is driven to cause vibrational motion at a certain frequency.

12. An illumination device, characterized in that, Comprising: A lamp head assembly, the lamp head assembly includes a lighting lamp; A power supply for supplying power to at least the lamp head assembly; A support housing for supporting at least the lighting lamp; A circuit board assembly, at least partially disposed in the support housing; The circuit board assembly is connected to the lamp head assembly to control the lighting lamp; the circuit board assembly includes at least one heating part, and the heating part generates a temperature rise during the operation of the lamp head assembly; An active heat dissipation assembly for dissipating heat from at least one of the lighting lamp or the circuit board assembly; the active heat dissipation assembly is configured to use vibrational motion to guide fluid flow so that the fluid flows through the surface of at least one of the heating parts or the lighting lamp to extract heat from at least one of the heating parts or the lighting lamp.

13. A battery pack for providing electrical energy to a power tool; characterized in that, Comprising: A battery pack housing, and at least one heating part that generates a temperature rise during the charging / discharging process of the battery pack is included in the battery pack housing; A battery cell, accommodated in the battery pack housing; An electric tool interface, disposed on the battery pack housing and configured to be coupled to the electric tool; An active heat dissipation component is disposed within the battery pack housing; the active heat dissipation component is configured to use vibrational motion to direct fluid flow such that the fluid flows across the surface of at least one of the heat generating portions to extract heat from at least one of the heat generating portions.

14. The battery pack according to claim 13, wherein, Further included is: During the charging / discharging process of the battery pack, the temperature of the battery cells rises, and the active heat dissipation component is disposed close to at least one of the battery cells.

15. The battery pack according to claim 14, wherein The battery cells supply electrical energy to the active heat dissipation component.

16. The battery pack according to claim 15, characterized in that, Also included is a circuit board assembly, at least partially disposed within the battery pack housing; the circuit board assembly at least controls the discharge circuit; the circuit board assembly includes at least one of the heat generating portions.

17. The battery pack according to claim 16, wherein, The active heat dissipation component is formed or connected to the circuit board assembly.

18. The battery pack according to claim 13, characterized in that, The battery pack housing includes at least one vent that permits fluid communication between the fluid within the battery pack and the external environment of the battery pack.

19. The battery pack according to claim 13, wherein The battery pack provides a nominal voltage greater than or equal to 12V and less than or equal to 100V.

20. A charger for charging a battery pack, characterized in that, Included are: A charger housing; A battery pack interface disposed on the charger housing, the battery pack interface configured to couple with the battery pack; A circuit board assembly, at least partially disposed within the housing; the circuit board assembly includes at least one heat generating portion that experiences a temperature rise when the charger charges the battery pack; an active heat dissipation component disposed within the charger housing; the active heat dissipation component is configured to use vibrational motion to direct fluid flow such that the fluid flows across the surface of at least one of the heat generating portions to extract heat from at least one of the heat generating portions.

21. The charger according to claim 20, wherein The heat generating portion includes a power semiconductor device or a transformer.

22. The charger according to claim 20, characterized in that, The charger housing includes at least one vent that permits fluid communication between the fluid within the charger and the external environment of the charger.

23. The charger according to claim 20, characterized in that, The circuit board assembly includes a circuit board body, the heat generating portion is disposed on the circuit board body, and the active heat dissipation component is connected to and in thermal contact with the circuit board body.

24. The charger according to claim 20, characterized in that, The circuit board assembly includes a circuit board body, the heat generating portion is disposed on the circuit board body, the active heat dissipation component is disposed on the circuit board body, and the active heat dissipation component is disposed close to the heat generating portion.

Images