CN112910177A

CN112910177A - Electric tool and mounting method of motor thereof

Info

Publication number: CN112910177A
Application number: CN201911217647.9A
Authority: CN
Inventors: 杨青松; 邹春贵
Original assignee: Nanjing Deshuo Industrial Co Ltd
Current assignee: Nanjing Chervon Industry Co Ltd; Nanjing Deshuo Industrial Co Ltd
Priority date: 2019-12-03
Filing date: 2019-12-03
Publication date: 2021-06-04

Abstract

The present invention provides an electric tool, including: the motor comprises a stator, a rotor and a fan, the motor extends along a first axis, the stator comprises a stator core and a stator winding wound on the stator core, the rotor comprises a motor shaft, a rotor core and a rotor winding wound on the rotor core, and the fan is driven by the motor shaft; the motor drives the output shaft to output; a housing assembly; a power supply device for supplying power to the electric tool; the electric tool further comprises a heat conduction device sleeved on the motor shaft, the heat conduction device comprises a first heat conduction part and a second heat conduction part, the first heat conduction part and the second heat conduction part are arranged at two ends of the heat conduction device, the first heat conduction part is arranged between the motor shaft and the fan, at least part of the first heat conduction part is attached to the fan surface, the second heat conduction part is arranged between the motor shaft and the rotor winding, and the rotor winding is wound on the second heat conduction part. The invention also provides a motor mounting method of the electric tool, and the electric tool effectively improves the heat dissipation efficiency and the heat dissipation stability.

Description

Electric tool and mounting method of motor thereof

Technical Field

The invention relates to an electric tool and a mounting method of a motor thereof.

Background

While electric tools are commonly used as auxiliary tools, they play an important role in the daily life of people, the problem of heat dissipation of the motor of the electric tool is an important factor affecting the performance of the electric tool. When the motor runs, the generated heat heats the motor structure, and when the temperature in the motor is too high, the magnetism of the magnet in the motor can be influenced, so that the motor fails, and the consequence that the electronic equipment cannot run or part of functions are damaged is caused.

The rotor of motor produces a large amount of heats and is difficult for getting rid of at the operation in-process, and because the rotor has increased its radiating degree of difficulty relatively more interior position relation for thereby the heat is detained inside the rotor and aggravates the temperature rise. The rotor structure combines the traditional rotor structure, the effective heat dissipation area of the rotor is very small, the additional heat dissipation piece is arranged, the performance of the rotor is easily influenced, and the heat dissipation piece additionally arranged on the rotor is easy to fall off or separate relative to the rotor due to the high-speed running state of the rotor during running, so that the heat dissipation effect is influenced, and the normal running of the motor is interfered. Traditional rotor structure has increased the heat dissipation difficulty of motor with arranging, causes the inside high temperature of instrument, influences machine performance.

Disclosure of Invention

In order to overcome the defects in the prior art, the present invention provides an electric tool with improved heat dissipation efficiency and stable heat dissipation performance, and a motor mounting method of the electric tool.

In order to achieve the above main object of the invention, there is provided an electric power tool including: the motor comprises a stator, a rotor and a fan, the motor extends along a first axis, the stator comprises a stator core and a stator winding wound on the stator core, the rotor comprises a motor shaft, a rotor core and a rotor winding wound on the rotor core, and the fan is driven by the motor shaft; the motor drives the output shaft to output; the motor is arranged in the shell assembly; a power supply device for supplying power to the electric tool; the electric tool further comprises a heat conduction device sleeved on the motor shaft, the heat conduction device comprises a first heat conduction part and a second heat conduction part, the first heat conduction part and the second heat conduction part are arranged at two ends of the heat conduction device, the first heat conduction part is arranged between the motor shaft and the fan, at least part of the first heat conduction part is attached to the fan surface, the second heat conduction part is arranged between the motor shaft and the rotor winding, and the rotor winding is wound on the second heat conduction part.

Optionally, the motor further includes an insulating support surrounding the motor shaft, and the insulating support is disposed between the motor shaft and the heat conducting device.

Optionally, the fan comprises: the fan shaft penetrates through the fan and forms a mounting hole, and the first heat conduction part is fixedly connected with the fan shaft through the mounting hole; and fan blades arranged on the periphery of the fan shaft.

Optionally, the length of the second heat conduction part on the first axis is greater than or equal to 10mm and smaller than or equal to 14 mm.

Optionally, the first heat conduction portion and the second heat conduction portion are in an axial shape and are sleeved outside the insulating support, and the outer diameter of the first heat conduction portion is larger than that of the second heat conduction portion.

Optionally, the wall thickness of the second heat conduction portion is greater than or equal to 0.8mm and less than or equal to 1.2 mm.

Optionally, the first heat conducting portion and the insulating support penetrate through the fan shaft in the first axial direction.

Optionally, the length of the first heat conduction portion on the first axis is greater than or equal to 10.5mm and less than or equal to 13.5 mm.

Optionally, the motor further includes a heat dissipation bracket partially disposed between the stator core and the stator winding, and the heat dissipation bracket extends at least partially outside the stator core and the stator winding.

In order to achieve the above main object of the present invention, there is provided a method of mounting a motor of an electric power tool, including mounting an insulating bracket outside a motor shaft; assembling a rotor iron core and sleeving a heat conduction device outside an insulation support on the motor shaft; winding a rotor winding on the second heat conducting portion of the heat conducting device; assembling a stator core wound with a stator winding and installing a commutator; the fan is sleeved outside the first heat conducting portion of the heat conducting device, and at least part of surface of the fan is in contact with the first heat conducting portion.

The invention provides an electric tool and a mounting method of a motor thereof, wherein a heat conducting device is partially mounted in a fan, a rotor winding is partially wound, partial heat generated by a rotor of the motor can be transferred to the fan in a heat conduction mode through the heat conducting device, the effective heat dissipation area of the motor is improved through the fan, and the heat in the fan and the motor is blown away through air flow generated by the fan driven by the rotor to rotate, so that the heat dissipation efficiency is effectively improved, the temperature rise in the electric tool is reduced, and the heat dissipation stability of the electric tool is improved.

Drawings

Fig. 1 is a perspective view schematically showing a power tool according to a first embodiment of the present invention.

Fig. 2 is a sectional view of the electric power tool of the first embodiment of the present invention.

Fig. 3 is a schematic structural view of a motor according to a first embodiment of the present invention.

Fig. 4 is an exploded schematic view of the motor of the first embodiment of the present invention.

Fig. 5 is a schematic view of the relationship between the fan and the heat conducting device according to the first embodiment of the present invention.

Fig. 6 is a flow chart illustrating a motor assembling method according to a first embodiment of the present invention.

Fig. 7 is a schematic view of a motor structure according to a second embodiment of the present invention.

Detailed Description

It will be understood by those skilled in the art that in the present disclosure, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in an orientation or positional relationship indicated in the drawings for ease of description and simplicity of description, and do not indicate or imply that the referenced devices or components must be in a particular orientation, constructed and operated in a particular orientation, and thus the above terms are not to be construed as limiting the present invention.

In a first preferred embodiment of the present invention, referring to fig. 1, a perspective view of an electric power tool according to the first embodiment of the present invention is shown. The invention provides an electric tool 100, the electric tool 100 has good heat dissipation capacity, the electric tool 100 can be a grass trimmer, a mower, an electric drill, an angle grinder, an electric hammer, a pruner and a chain saw, and is not limited to the type of the electric tool 100, and the invention also provides a motor 200 structure which can be applied to the electric tool 100.

Fig. 2 is a sectional view of the electric power tool of the first embodiment of the present invention. In the present embodiment, referring to fig. 2, the electric power tool 100 includes: the power tool comprises a motor 200, an output shaft 110, a housing assembly 120 and a power supply device, wherein the motor 200 is arranged in the housing assembly 120, the motor 200 drives the output shaft 110 to output work, the power supply device is used for supplying power to the power tool 100, optionally, the power supply device can be a battery pack which supplies power to the power tool 100 through a driving circuit connected with the motor 200, and the power supply device can also be a power line connected with the driving circuit, which is not detailed herein. The power tool 100 may also include a tool holder for holding tool accessories depending on the type of tool, such as a tool holder for holding various types of bits to accommodate different fastener operations when the power tool 100 is a power screwdriver. When the power tool 100 is an angle grinder, it further includes a tool chuck for mounting a grinding plate, which is driven by the output shaft 110 to rotate to cut and grind a workpiece, and the specific working principle of the present invention is disclosed below by taking the angle grinder as an example.

Fig. 3 is a schematic structural view of a motor according to a first embodiment of the present invention. Fig. 4 is an exploded schematic view of the motor of the first embodiment of the present invention. Referring to fig. 3 and 4, the motor 200 includes a stator 210, a rotor 220, and a fan 230, the rotor 220 includes a rotor core 221, a rotor winding 222 wound around the rotor core 221, and a motor shaft 223, the motor shaft 223 extends along the first axis 101, and the stator 210 includes a stator core 212 and a stator winding 211 wound around the stator core 212. In the present embodiment, the rotor 220 is disposed inside the stator 210, sleeved on the motor shaft 223, and fixedly connected to the motor shaft 223, and generates a rotating magnetic field through the stator 210 and acts on the rotor 220 to form a rotating torque. When the power tool 100 is operated, the motor shaft 223 is rotated. The fan 230 is attached to the motor shaft 223, and when the motor shaft 223 rotates, the fan 230 attached to the motor shaft 223 is rotated, and a heat dissipation air current is generated to dissipate heat from the motor 200 and the inside of the power tool 100.

The housing assembly 120 includes at least a grip portion for gripping, and if necessary, the housing assembly 120 further includes a motor housing for accommodating the motor 200. The electric tool also comprises a switch, wherein the switch is connected to the driving circuit and is used for controlling the opening and closing of the driving circuit so as to control the operation of the electric tool. In some power tools, such as angle grinders, a transmission mechanism is further included, which is connected to the output shaft 110 and to the motor shaft 223 of the motor 200 through a transmission mechanism for decelerating the output shaft, and includes first and second gears that mesh with each other and have different gear ratios so that the transmission mechanism can decelerate.

The electric tool 100 further includes a heat conduction device 300 sleeved on the motor shaft 223, the heat conduction device 300 includes a first heat conduction portion 310 and a second heat conduction portion 320 arranged at two ends of the heat conduction device, the first heat conduction portion 310 is arranged between the motor shaft 223 and the fan 230, at least a part of the first heat conduction portion 310 is attached to the fan 230, the second heat conduction portion 320 is arranged between the motor shaft 223 and the rotor winding 222, and the rotor winding 222 is wound on the second heat conduction portion 320. The heat conduction device 300 is connected to the fan 230 and the rotor 220 of the motor 200, so that when the power tool 100 operates, a part of heat generated by the motor 200 is transferred to the fan 230 through the heat conduction device 300, the heat of the rotor 220 is transferred to the fan 230 through the heat conduction device 300, the heat on the fan 230 is taken away by high-speed airflow around the surface of the fan 230, and the heat dissipation power of the motor 200 is improved.

Fig. 5 is a schematic view of the relationship between the fan and the heat conducting device according to the first embodiment of the present invention. The fan 230 includes a fan shaft 232 and fan blades 233 disposed around the fan shaft 232, and preferably, the fan shaft 232 and the fan blades 233 are integrally formed and made of the same material. The fan shaft 232 penetrates the fan 230 and forms a mounting hole 234, and the mounting hole 234 is matched in shape with the heat conduction device 300 so that the heat conduction device 300 and the fan 230 are fixedly connected. In one embodiment, the first heat conduction portion 310 is in a non-cylindrical shaft shape, for example, the sidewall of the first heat conduction portion 310 is provided with at least one flat surface, and the corresponding mounting hole 234 is configured to correspond to the first heat conduction portion 310, so that the first heat conduction portion 310 is inserted into the mounting hole 234 to be fixedly connected and can rotate in unison at least in the rotation direction around the first axis 101, and referring to fig. 5 in particular, the mounting hole 234 and the heat conduction device 300 are fixedly connected by a flat position. It is understood that the first heat conduction portion 310 and the fan 230 may be fixedly connected by other connection methods, such as screw connection, other clamping methods, and interference fit, and will not be described in detail herein. The fan shaft 232 and the first heat conduction portion 310 are configured to be in surface contact with each other so as to ensure that the fan 230 can effectively receive the heat generated by the rotor 220. The plurality of blades 233 have a certain gap between the plurality of blades 233, so that the effective heat dissipation area of the fan 230 is increased by the plurality of blades 233, and the volume of the fan 230 is increased, thereby a large amount of heat generated by the rotor 220 can be transferred into the fan 230, and the heat can be dissipated rapidly by the plurality of blades 233 of the fan 230.

The motor 200 further includes an insulating bracket 224, the insulating bracket 224 surrounds the motor shaft 223, the insulating bracket 224 is disposed between the motor shaft 223 and the heat conduction device 300, and the insulating bracket 224 wraps at least a portion of the motor shaft 223, so that the motor shaft 223 and the rotor 220 are isolated and insulated, thereby preventing a short circuit of an internal circuit of the motor 200. The insulating support 224 includes an insulating shaft wrapping the motor shaft 223 and an extension 2241 provided on the insulating shaft, the extension 2241 being used to fixedly support the rotor core 221 so that the rotor 220 is mounted to the insulating support 224 and integrally rotated with the motor shaft 223. The fan 230 is mounted to one end of the motor shaft 223, and the heat transfer device 300 is disposed between the fan 230 and the rotor 220. The first heat conduction portion 310 of the heat conduction device 300 is disposed in the fan shaft 232, and the second heat conduction portion 320 of the heat conduction device 300 extends toward the rotor 220 and is disposed in the rotor 220.

Specifically, the second heat conduction portion 320 is disposed between the rotor winding 222 and the insulating support 224, and the rotor winding 222 is wound around the second heat conduction portion 320, so that when the power tool 100 is in operation, heat generated by the rotor winding 222 can be directly and rapidly transferred to the second heat conduction portion 320, the heat is transferred to the fan 230 through the first heat conduction portion 310 directly contacting with the fan 230, and heat is blown away by the heat dissipation airflow generated by the fan 230, thereby effectively improving heat dissipation efficiency. Further, the fan 230 is connected to the rotor 220, so that the heat dissipation surface area of the rotor 220 is indirectly increased, the heat exchange area between the rotor 220 and the air is increased, and the heat exchange power of the rotor 220 can be increased.

The stator core 212 includes a core base and a winding portion provided to be connected to the core base, the winding portion being used to wind the stator winding 211. The core substrate is preferably provided as a hollow cylinder, and the winding portions extend inward from the inner surface of the core substrate, and the winding portions are provided in plurality and symmetrically distributed inside the core substrate. Specifically, wire winding portion includes wire winding portion and protection end, and the protection end is formed at the tip of wire winding portion to extend to both sides from the tip of wire winding portion, thereby the width of protection end is greater than the width of wire winding portion cross section, and when stator winding 211 twined on the iron core substrate, the protection end was used for intercepting fixed stator winding 211, and played the guard action to stator winding 211.

Preferably, a material with high heat dissipation property is used as a material for manufacturing the fan 230, such as a part of metal materials, such as aluminum alloy, copper, etc., or other non-metal materials with high heat dissipation property, such as graphite, carbon fiber, etc., and a material with a heat dissipation coefficient higher than 110W/(m · K) is selected as a material for manufacturing or a part of the material for manufacturing the main body of the fan 230, so as to meet the heat dissipation requirement of the electric power tool 100, especially the high-power electric power tool 100, during operation. Similarly, the heat conducting device 300 may also be made of a material with high heat dissipation performance, such as a metal material or a carbon fiber, so that the heat generated by the rotor 220 may be transmitted to the fan 230 through the heat conducting device 300 in time, thereby further improving the heat dissipation efficiency of the motor 200. Optionally, one end of the fan 230 is further provided with a fan cover 231 for fixing the fan 230 relatively, and the fan cover 231 is disposed at the other end of the fan relative to the first heat conducting portion 210.

Specifically, in order to ensure that the heat generated by the rotor winding 222 and the rotor core 221 can be effectively transmitted to the heat conducting device 300, the length of the second heat conducting portion 320 on the first axis 101 is greater than or equal to 10mm and less than or equal to 14mm, and the rotor winding 222 is wound on the second heat conducting portion 320, so that the contact area between the rotor winding 222 and the second heat conducting portion 320 is increased, and the heat generated by the rotor winding 222 is sufficiently transmitted to the motor 200. In order to shorten the overall length of the motor 200 and prevent the motor 200 from being sized, the electric tool 100 is oversized, and the length of the second heat conduction part 320 on the first axis 101 does not exceed 14mm, so that the motor 200 is compact. Preferably, the length of the second heat conduction portion 320 is 11mm to 12mm, so that the heat dissipation efficiency of the motor 200 can be ensured on the premise that the motor 200 is compact.

Further, the first heat conduction portion 310 and the second heat conduction portion 320 are in a shaft shape and sleeved outside the insulating support 224, and the outer diameter of the first heat conduction portion 310 is larger than that of the second heat conduction portion 320. Since the rotor core 221 is disposed to be wound around the second heat conduction part 320, the outer diameter of the second heat conduction part 320 cannot be excessively large, preventing the rotor winding 222 wound around the second heat conduction part 320 from protruding beyond the position of the rotor 220, or causing the rotor 220 to collide with the stator 210 during rotation, causing structural damage to the motor 200. Specifically, the wall thickness L of the second heat conducting portion 320 is greater than or equal to 0.8mm and less than or equal to 1.2mm, so that the performance of the motor 200 is not affected by the installation of the second heat conducting portion 320 in the rotor 220 on the premise of ensuring the strength and the heat transfer performance of the second heat conducting portion 320, and the heat dissipation efficiency of the motor 200 and the inside of the electric tool 100 is effectively improved.

The insulating support 224 is directly sleeved on the motor shaft 223, the first heat conduction part 310 is fixedly connected outside the insulating support 224, and the fan 230 is fixed through the first heat conduction part 310, so that the fan 230, the first heat conduction part 310, the motor shaft 223 and the insulating support 224 rotate synchronously when the motor 200 operates. Preferably, the first heat conduction part 310 and the insulating bracket 224 penetrate the fan shaft 232 in the direction of the first axis 101, so that the first heat conduction part 310 and the insulating bracket 224 are both disposed between the fan shaft 232 and the motor shaft 223, thereby ensuring that the fan 230 and the heat conduction device 300 are in sufficient contact, so that the heat generated by the rotor 220, especially the heat generated by the rotor winding 222, can be effectively transferred to the fan 230. Further, the length of the first heat conduction portion 310 in the first axis 101 is greater than or equal to 10.5mm and less than or equal to 13.5mm, so as to ensure an effective contact area between the first heat conduction portion 310 and the fan 230, so that the fan 230 can timely receive heat transferred by the heat conduction device 300, and thus the heat dissipation effect of the power tool 100 is ensured.

The invention can improve the heat radiation performance of the motor 200, and the heat radiation performance of the motor 200 is higher due to the higher temperature rise of the motor 200 in the operation process of the high-power electric tool 100, and the heat radiation speed of the motor 200 can be effectively improved by the heat radiation mode of the invention, thereby ensuring the smooth operation of the high-power electric tool 100. On the premise of reducing the size of the motor 200, the heat dissipation requirement of the motor 200 with the power within 2200W can be still met, so that the running performance of the electric tool 100 is improved.

Fig. 6 is a flow chart illustrating a motor assembling method according to a first embodiment of the present invention. Referring to fig. 6, the present invention provides a motor 200 and an assembling method thereof, the motor 200 including a stator 210, a rotor 220, and a fan 230, the rotor 220 including a rotor core 221 and a rotor winding 222 wound around the rotor core 221, and a motor shaft 223, the motor shaft 223 extending along a first axis 101, the stator 210 including a stator core 212 and a stator winding 211 wound around the stator core 212. In the present embodiment, the rotor 220 is disposed inside the stator 210, sleeved on the motor shaft 223, and fixedly connected to the motor shaft 223, and generates a rotating magnetic field through the stator 210 and acts on the rotor 220 to form a rotating torque. When the power tool 100 is operated, the motor shaft 223 is rotated. The fan 230 is attached to the motor shaft 223, and when the motor shaft 223 rotates, the fan 230 attached to the motor shaft 223 is rotated, and a heat dissipation air current is generated to dissipate heat from the motor 200 and the inside of the power tool 100.

The electric tool 100 further includes a heat conduction device 300 sleeved on the motor shaft 223, the heat conduction device 300 includes a first heat conduction portion 310 and a second heat conduction portion 320 arranged at two ends of the heat conduction device, the first heat conduction portion 310 is arranged between the motor shaft 223 and the fan 230, at least a part of the first heat conduction portion 310 is attached to the fan 230, the second heat conduction portion 320 is arranged between the motor shaft 223 and the rotor winding 222, and the rotor winding 222 is wound on the second heat conduction portion 320.

Now, an assembling method of the motor 200 is provided, and S1: an insulating bracket 224 is arranged outside the motor shaft 223; s2: assembling a rotor core 221 and sleeving the heat conduction device 300 outside an insulating bracket 224 on a motor shaft 223; s3: winding the rotor winding 222 around the heat conducting device 300, in particular around the second heat conducting portion 320; s4: a stator core 212 wound with a stator winding 211 is assembled and a commutator 225 is installed; s5: the fan 230 is mounted on the motor shaft 223, and the fan 230 is sleeved and at least partially contacted with the heat conducting device 300 in a surface contact manner, specifically, the fan is sleeved outside the first heat conducting part 310 of the heat conducting device 300, and at least partially contacted with the first heat conducting part 310 in a surface contact manner.

Through the above steps, the heat conduction device 300 is installed in the rotor winding 222, so that heat generated by the rotor winding 222 during the operation of the motor 200 is transferred to the fan 230 through the wound heat conduction device 300, and the temperature drop during the operation of the motor 200 is effectively reduced. The first heat conduction part 310 of the heat conduction device 300 is installed and fixed in the fan shaft 232, and the second heat conduction part 320 is used as a winding object of the rotor winding 222, so that the heat conduction device 300 is stably connected and tightly contacted with the fan 230 and the rotor 220, respectively, thereby ensuring the stable heat dissipation effect of the heat conduction device 300, being not easy to separate or separate from the fan 230 and the rotor 220, and avoiding the reduction of the heat dissipation effect and the weakening of the performance of the motor 200.

In a second preferred embodiment of the present invention, there is provided an electric tool, fig. 7 is a schematic structural view of a motor according to the second embodiment of the present invention, and referring to fig. 7, a motor 200a of the electric tool includes a stator, a rotor and a fan, the rotor includes a rotor core and a rotor winding wound around the rotor core, and a motor shaft, the motor shaft extends along a first axis, and the stator includes a stator core 211a and a stator winding 212a wound around the stator core 211 a. The heat dissipation bracket 330 is disposed between the stator winding 212a and the stator core 211a to solve the problem that the heat conductivity of the stator core is low, which affects the heat dissipation of the stator winding and the stator core.

In this embodiment, as in the first preferred embodiment, the electric tool further includes a heat conduction device (not shown) sleeved on the motor shaft, the heat conduction device includes a first heat conduction portion and a second heat conduction portion disposed at two ends of the heat conduction device, the first heat conduction portion is disposed between the motor shaft and the fan, and at least a portion of the first heat conduction portion is attached to the fan surface, the second heat conduction portion is disposed between the motor shaft and the rotor winding, and the rotor winding is wound on the second heat conduction portion. The heat transfer device connects the fan and the rotor of the motor so that a portion of heat generated from the motor is transferred to the fan through the heat transfer device 300 when the power tool is operated.

The heat dissipation bracket 330 is inserted and fixed to the stator core to improve the heat dissipation efficiency of the stator. The stator core has at least one heat dissipation groove adapted to the structure of the heat dissipation bracket 330, so that the heat dissipation bracket 330 is inserted into the stator core through the heat dissipation groove. The stator core has a first surface and a second surface, which are oppositely formed on both sides of the stator core, and the winding part extends inwards from the first surface. The heat dissipation grooves are correspondingly arranged on the first surface and the second surface, the heat dissipation bracket 330 is correspondingly placed into the heat dissipation grooves, and the heat dissipation bracket 330 is in surface contact with the stator core and the coil winding.

The heat dissipation bracket 330 is in contact with the coil windings through the inner surface of the heat dissipation groove, in the operation process of the motor 200, the high-temperature coil windings transfer heat to the heat dissipation bracket 330 through heat conduction, part of the heat dissipation bracket 330 is exposed in the air, and the fan forms high-flow airflow to blow away the heat of the heat dissipation bracket 330 when the motor 200 operates, so that the heat generated by the stator core and the stator windings is dissipated quickly.

In the description herein, reference to the description of the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the various embodiments or examples and features of the various embodiments or examples described in this specification can be combined and combined by those skilled in the art without contradiction.

It will be appreciated by persons skilled in the art that the embodiments of the invention described above and shown in the drawings are given by way of example only and are not limiting of the invention. The objects of the invention have been fully and effectively accomplished. The functional and structural principles of the present invention have been shown and described in the embodiments, and any variations or modifications may be made to the embodiments of the present invention without departing from the principles.

Claims

1. A power tool, comprising:

a motor including a stator core and a stator winding wound around the stator core, a rotor including a motor shaft rotating along a first axis, a rotor core, and a rotor winding wound around the rotor core, and a fan driven by the motor shaft;

the motor drives the output shaft to output;

the motor is arranged in the shell assembly;

a power supply device for supplying power to the electric tool;

the method is characterized in that: the electric tool further comprises a heat conduction device sleeved on the motor shaft, the heat conduction device comprises a first heat conduction part and a second heat conduction part, the first heat conduction part and the second heat conduction part are arranged at two ends of the heat conduction device, the first heat conduction part is arranged between the motor shaft and the fan, at least part of the first heat conduction part is attached to the surface of the fan, the second heat conduction part is arranged between the motor shaft and the rotor winding, and the rotor winding is wound on the second heat conduction part.

2. The power tool of claim 1, wherein: the motor further comprises an insulating support, the insulating support surrounds the motor shaft, and the insulating support is arranged between the motor shaft and the heat conducting device.

3. The power tool of claim 2, wherein: the fan includes:

the fan shaft penetrates through the fan and forms a mounting hole, and the first heat conduction part is fixedly connected with the fan shaft through the mounting hole;

and fan blades arranged on the periphery of the fan shaft.

4. The power tool of claim 3, wherein: the length of the second heat conduction part on the first axis is more than or equal to 10mm and less than or equal to 14 mm.

5. The power tool of claim 3, wherein: the first heat conduction part and the second heat conduction part are in an axial shape and are sleeved outside the insulating support, and the outer diameter of the first heat conduction part is larger than that of the second heat conduction part.

6. The electric power tool according to claim 4 or 5, characterized in that: the wall thickness of the second heat conduction part is more than or equal to 0.8mm and less than or equal to 1.2 mm.

7. The power tool of claim 6, wherein: the first heat conduction part and the insulating support penetrate through the fan shaft in the first axial direction.

8. The power tool of claim 7, wherein: the length of the first heat conduction part on the first axis is more than or equal to 10.5mm and less than or equal to 13.5 mm.

9. The power tool of claim 3, wherein: the motor further comprises a heat dissipation support partially arranged between the stator core and the stator winding, and the heat dissipation support at least partially extends out of the stator core and the stator winding.

10. A method for mounting a motor of an electric tool is characterized in that:

an insulating bracket is arranged outside a motor shaft;

assembling a rotor iron core and sleeving a heat conduction device outside an insulation support on the motor shaft;

winding a rotor winding on the second heat conducting portion of the heat conducting device;

assembling a stator core wound with a stator winding and installing a commutator;

the fan is sleeved outside the first heat conducting portion of the heat conducting device, and at least part of surface of the fan is in contact with the first heat conducting portion.