CN215920046U

CN215920046U - Electric tool

Info

Publication number: CN215920046U
Application number: CN202121759310.3U
Authority: CN
Inventors: 徐中全; 陈亮; 杨青松; 刘天亮
Original assignee: Nanjing Chervon Industry Co Ltd
Current assignee: Nanjing Chervon Industry Co Ltd
Priority date: 2020-08-10
Filing date: 2021-07-29
Publication date: 2022-03-01
Anticipated expiration: 2031-07-29
Also published as: CN216681618U

Abstract

The utility model discloses an electric tool, comprising: an output member for outputting power; a motor for driving the output member; the speed reducing assembly is used for realizing power transmission between the motor and the output member; a housing including a handle housing and a head housing; the motor includes: a motor shaft rotatable about a first axis; a stator core surrounding the motor shaft; a first bearing mounted to the motor shaft and located at an upper side of the stator core; a second bearing mounted to the motor shaft and located at a lower side of the stator core; the handle shell comprises a holding part extending along a first straight line direction which is perpendicular to or obliquely intersected with the first axis, the motor is arranged in the head shell, and the distance between the first bearing and the second bearing is greater than or equal to 28 mm and smaller than or equal to 42 mm. The electric tool is convenient for a user to hold, and has smaller size and more compact structure.

Description

Electric tool

Technical Field

The utility model relates to an electric tool, in particular to an angle grinder.

Background

An angle grinder is an electric tool, which is mainly used for cutting, grinding and brushing metal and stone materials. The motor of current angle grinder sets up in the handle casing usually, and this makes the handle casing thicker for it is harder to hold, and the operation is got up unstably. And the motor sets up in the handle casing and makes the angle grind after long-term operation, handle casing department can become hotter for the user feels uncomfortable.

SUMMERY OF THE UTILITY MODEL

To overcome the disadvantages of the prior art, the present invention provides a power tool with a smaller size and a more comfortable grip for the user.

In order to achieve the above object, the present invention adopts the following technical solutions:

a power tool, comprising: an output member for outputting power; a motor for driving the output member; the speed reducing assembly is used for realizing power transmission between the motor and the output member; a housing including a handle housing and a head housing; the motor includes: a motor shaft rotatable about a first axis; a stator core surrounding the motor shaft; a first bearing mounted to the motor shaft and located at an upper side of the stator core; a second bearing mounted to the motor shaft and located at a lower side of the stator core; the handle shell comprises a holding part extending along a first straight line direction which is perpendicular to or obliquely intersected with the first axis, the motor is arranged in the head shell, and the distance between the first bearing and the second bearing is greater than or equal to 28 mm and smaller than or equal to 42 mm.

In some embodiments, the power tool further comprises: a fan at least partially disposed within the head housing; the fan includes a mounting portion for mounting the fan to the motor shaft, the mounting portion being disposed between the first bearing and the second bearing.

In some embodiments, the electric machine further comprises: a balance weight mounted to the motor shaft; the mounting portion of the fan is mounted to the balance weight.

In some embodiments, the electric machine further comprises: a balance weight mounted to the motor shaft; the balance weight is arranged on the lower side of the stator core; the size of the balance weight, the fan and the second bearing in the first axial direction is larger than or equal to 13 mm and smaller than or equal to 21 mm.

In some embodiments, the mounting portion is disposed between the second bearing and the stator core.

In some embodiments, the fan further comprises: a blade part including a plurality of blades; the fan blade part sinks relative to the mounting part, and the plurality of fan blades are at least partially distributed in the circumferential direction around the second bearing.

In some embodiments, the electric machine further comprises: a first bracket for supporting the stator core and at least partially disposed at an upper side of the stator core; the dimension of the whole of the first bearing and the first bracket in the first axial direction is smaller than the sum of the dimension of the first bearing in the direction and the dimension of the first bracket in the direction.

In some embodiments, the electric machine further comprises: the second bracket is used for supporting the stator core and is at least partially arranged at the lower side of the stator core; the second bracket surrounds a through hole formed for the motor shaft to pass through, and the electric tool further comprises a fan mounted to the motor shaft, the fan extending at least partially into the through hole.

In some embodiments, the electric machine further comprises: a coil winding wound to the stator core; a terminal assembly for coupling power to the coil winding; the terminal assembly is disposed at a sidewall of the stator core.

In some embodiments, the height of the head shell in the first axial direction is equal to or greater than 70 mm and equal to or less than 90 mm.

A power tool, comprising: an output member for outputting power; a motor for driving the output member, the motor including a motor shaft rotatable about a first axis; the circuit board is electrically connected with the motor; the motor is arranged in the head shell, and the handle shell comprises a holding part extending along a first linear direction which is vertical to or obliquely intersected with the first axis; the output piece is at least partially arranged in the head shell, and the circuit board is arranged in the handle shell; wherein, the ratio of the total weight of the handle shell and the first part at least partially positioned in the handle shell to the total weight of the head shell and the second part at least partially positioned in the head shell is more than or equal to 0.4 and less than or equal to 0.55.

In some embodiments, the handle housing and the head housing form a detachable connection.

In some embodiments, the head shell is disposed at a front end of the handle housing, the handle housing further comprising a coupling portion disposed at a rear end for coupling to the energy source.

In some embodiments, the total weight of the head shell and the second type of part at least partially within the head shell is 800 grams or greater and 900 grams or less.

In some embodiments, a cross section of the grip portion in a plane perpendicular to the first linear direction is substantially a closed curve, and a product of a circumference of the closed curve and a height of the head shell is greater than or equal to 11000 square millimeters and less than or equal to 14300 square millimeters.

In some embodiments, the power tool further comprises: a battery pack detachably mounted to the handle housing; in the first straight line direction, the distance between the center of gravity of the electric tool and the first axis is greater than or equal to 100 mm and less than or equal to 125 mm.

In some embodiments, a ratio of a dimension of the grip portion in the first linear direction to a dimension of the handle case in the first linear direction is 0.5 or more and 0.8 or less.

In some embodiments, the height of the head shell in the first axial direction is equal to or greater than 75 millimeters and equal to or less than 85 millimeters.

In some embodiments, the total weight of the handle housing and the first type of part at least partially within the handle housing is equal to or greater than 300 grams and equal to or less than 450 grams.

In some embodiments, the cross section of the holding part in a plane perpendicular to the first straight line direction is basically a closed curve, and the ratio of the input power of the motor to the perimeter of the closed curve is greater than or equal to 2.8 watts per millimeter and less than or equal to 5 watts per millimeter.

A power tool, comprising: an output member for outputting power; a motor for driving the output member; the speed reducing assembly is used for realizing power transmission between the motor and the output member; the shell comprises a handle shell and a head shell, and the motor is arranged in the head shell; the motor includes: a motor shaft rotatable about a first axis; a stator core surrounding the motor shaft; a first bearing mounted to the motor shaft and located at an upper side of the stator core; a second bearing mounted to the motor shaft and located at a lower side of the stator core; the handle shell comprises a holding part extending along a first straight line direction which is vertical to or obliquely intersected with the first axis, the cross section of the holding part in a plane vertical to the first straight line direction is basically a closed curve, and the product of the perimeter of the closed curve and the height of the head shell is greater than or equal to 11000 square millimeters and smaller than or equal to 14300 square millimeters.

In some embodiments, the gear ratio of the speed reduction assembly is equal to or greater than 3 and equal to or less than 4.

In some embodiments, the height of the head shell is equal to or greater than 75 millimeters and equal to or less than 85 millimeters.

In some embodiments, the ratio of the input power of the motor to the circumference of the closed curve is greater than or equal to 2.8 watts per millimeter and less than or equal to 5 watts per millimeter.

In some embodiments, the distance between the first bearing and the second bearing is 28 millimeters and 42 millimeters or less.

In some embodiments, the power tool further comprises: a fan at least partially disposed within the head housing; the motor further includes: a balance weight mounted to the motor shaft; the fan includes a mounting portion for mounting the fan to the motor shaft, the mounting portion of the fan being mounted to the weight.

In some embodiments, the weight, the fan, and the second bearing may form an entirety having a dimension in the first axial direction of 13 mm or more and 21 mm or less.

A power tool, comprising: an output member for outputting power; a motor for driving the output member; the speed reducing assembly is used for realizing power transmission between the motor and the output member; the shell comprises a handle shell and a head shell, and the motor is arranged in the head shell; the motor includes: a motor shaft rotatable about a first axis; a stator core surrounding the motor shaft; a first bearing mounted to the motor shaft and located at an upper side of the stator core; a second bearing mounted to the motor shaft and located at a lower side of the stator core; wherein, the ratio of the input power of the motor to the height of the head shell along the first axial direction is more than or equal to 5 watts per millimeter and less than or equal to 10 watts per millimeter.

The utility model has the advantages that: the motor is arranged in the head shell, and the holding part is thinner, so that the size of the head shell is smaller, the holding is convenient for a user, and meanwhile, the size of the electric tool is smaller and the structure is more compact.

Drawings

FIG. 1 is a plan view of a power tool;

FIG. 2 is a perspective view of the power tool of FIG. 1;

FIG. 3 is a cross-sectional view of the power tool of FIG. 1;

FIG. 4 is a perspective view of the power tool of FIG. 1 with the handle housing detached;

FIG. 5 is a plan view of the head housing and a first type of component at least partially within the head housing of the power tool of FIG. 1;

FIG. 6 is a cross-sectional view of the structure shown in FIG. 5;

FIG. 7 is an exploded view of the structure shown in FIG. 5;

FIG. 8 is an exploded view of the motor and fan of FIG. 7;

FIG. 9 is a plan view of the handle housing of FIG. 1;

FIG. 10 is a cross-sectional view of the handle housing of FIG. 9 in one plane;

fig. 11 is a perspective view of the fan in fig. 7.

Detailed Description

The power tool 100 shown in fig. 1 may be an angle grinder, which performs grinding, cutting, and the like according to different mounting accessories. As shown in fig. 1 to 3, the electric power tool 100 includes: housing 11, motor 12, output member 13, and reduction assembly 14.

The housing 11 is adapted to house a motor 12 and a reduction assembly 14. The shell 11 comprises a handle shell 111 and a head shell 112, the handle shell 111 and the head shell 112 form a detachable connection, the handle shell 111 and the head shell 112 are connected through a plurality of screws, and the handle shell 111 and the head shell 112 can be separated through detaching the screws, so that parts in the shell 11 can be maintained conveniently. The handle housing 111 extends substantially along the first straight line 101, the handle housing 111 includes a grip portion 111a for gripping by a user, and the grip portion 111a extends along the first straight line 101. The handle case 111 includes a front end and a rear end in the direction along the first straight line 101, the head case 112 is disposed at the front end of the handle case 111, and the rear end of the handle case 111 provides a coupling portion 111b for coupling the energy source. Specifically, the electric power tool 100 further includes a battery pack, and the coupling portion 111b is configured to detachably couple the battery pack, which is configured to supply power to the motor 12. In other embodiments, the joint 111b may also be connected with an ac cable.

The motor 12 is disposed in the head housing 112, and the motor 12 is used for driving the output member 13 to rotate so as to output power. The motor 12 comprises a motor shaft 121 rotatable about a first axis 102, and the output member 13 is rotatable about a second axis 103, the second axis 103 being parallel to the first axis 102, the second axis 103 being spaced from the first axis 102 by a distance. The speed reduction assembly 14 is disposed between the motor shaft 121 and the output member 13 such that the speed reduction assembly 14 enables power transmission between the motor 12 and the output member 13. The speed reduction assembly 14 enables the rotational speed output by the motor shaft 121 to be reduced to be transmitted to the output member 13, so that a higher output torque can be obtained by the output member 13, thereby improving the loading capacity of the power tool 100. In the present embodiment, the first axis 102 and the first straight line 101 are perpendicular to each other, and the second axis 103 and the first straight line 101 are perpendicular to each other. In other embodiments, the first axis 102 may also obliquely intersect the first straight line 101.

As shown in fig. 2 and 4, the handle case 111 includes a left case 111c and a right case 111 d. As shown in fig. 3 and 4, the left housing 111c and the right housing 111d are butted to form a first accommodating chamber 111 e. The head housing 112 surrounds and forms a second accommodation chamber 112a, and the second accommodation chamber 112a and the first accommodation chamber 111e communicate with each other. As shown in fig. 5 to 7, the head housing 112 includes an upper housing 112b, a middle housing 112c, and a lower housing 112d, the middle housing 112c being disposed between the upper housing 112b and the lower housing 112 d. The upper case 112b, the middle case 112c, and the lower case 112d are sequentially arranged in the first axis 102 direction. The upper case 112b and the middle case 112c are butted to form an upper receiving chamber 112e, and the middle case 112c and the lower case 112d are butted to form a lower receiving chamber 112 f. The motor 12 is disposed substantially within the upper receiving chamber 112e, and the motor shaft 121 extends from the upper receiving chamber 112e into the lower receiving chamber 112 f. The reduction assembly 14 is disposed in the lower receiving chamber 112f, and the output member 13 is partially disposed in the lower receiving chamber 112f, so that the height L1 of the head housing 112, which is the dimension of the head housing 112 in the direction of the first axis 102, can be effectively reduced, and the height L1 of the head housing 112 refers to the dimension of the head housing 112.

As shown in fig. 7 and 8, the motor 12 further includes: a stator core 122, a coil winding 123, a first bracket 124, and a second bracket 125. A stator core 122 surrounds the motor shaft 121, and a coil winding 123 is wound to the stator core 122. The first bracket 124 serves to position the stator core 122 at an upper side of the stator core 122, and the second bracket 125 serves to position the stator core 122 at a lower side of the stator core 122. The motor 12 further includes: a first bearing 126 and a second bearing 127. The first bearing 126 is mounted to the motor shaft 121 to support the motor shaft 121, and the second bearing 127 is mounted to the motor shaft 121 to support the motor shaft 121. The first bearing 126 is disposed at an upper side of the stator core 122, and the second bearing 127 is disposed at a lower side of the stator core 122. The first bearing 126 and the second bearing 127 support the motor shaft 121, thereby improving the positioning accuracy of the motor 12. The distance L2 between the first bearing 126 and the second bearing 127 is equal to or greater than 28 mm and equal to or less than 42 mm. Further, the distance L2 between the first bearing 126 and the second bearing 127 is equal to or greater than 30 mm and equal to or less than 40 mm. Further, the distance L2 between the first bearing 126 and the second bearing 127 is equal to or greater than 32 mm and equal to or less than 38 mm. In this way, while the motor 12 is disposed inside the head housing 112, the height L1 of the head housing 112 can be made as low as possible, so that the grip portion 111a of the electric power tool 100 of the present embodiment can be made thinner without increasing the height L1 of the head portion of the electric power tool 100. Furthermore, in the electric power tool 100 of the present embodiment, on the premise that the grip portion 111a is thinner and more suitable for the user to grip, the height L1 of the head housing 112 can be reduced, so that the grip portion 111a is thinner and the size of the head is not increased compared to the conventional tool in which the motor 12 is disposed in the grip portion 111 a.

As shown in fig. 9 and 10, the cross section of the grip portion 111a in a plane P1 perpendicular to the first straight line 101 is substantially a closed curve 111f, and the closed curve 111f is substantially elliptical. The closed curve 111f may be considered as the outer circle of the section. In other embodiments, the closed curve 111f may be a circle or other closed figure. It should be noted that, in the present embodiment, although the handle housing 111 includes the left housing 111c and the right housing 111d which can be separated, the cross section of the grip portion 111a formed by the butt joint of the left housing 111c and the right housing 111d can be regarded as the closed curve 111 f. The product of the circumference of the closed curve 111f and the height L1 of the head shell 112 is 11000 square millimeters or more and 14300 square millimeters or less. Further, the product of the circumference of the closed curve 111f and the height L1 of the head shell 112 is 12000 square millimeters or more and 13200 square millimeters or less. In this way, the height L1 of the head case 112 can be made small while the grip portion 111a is made thin for the user to stably grip, which is advantageous for downsizing the electric power tool 100. The ratio of the input power of the motor 12 to the circumference of the closed curve 111f is 2.8 watts per millimeter or more and 55 watts per millimeter or less. Further, the ratio of the input power of the motor 12 to the perimeter of the closed curve 111f is greater than or equal to 3 watts per millimeter and less than or equal to 4.5 watts per millimeter, so that the output power of the electric tool 100 can still meet the working requirement under the condition that the size of the electric tool 100 is reduced.

The ratio of the input power of the motor 12 to the height L1 of the head housing 112 in the direction of the first axis 102 is greater than or equal to 5 watts per millimeter and less than or equal to 10 watts per millimeter, so that the head housing 112 of the electric power tool 100 has a small size and a large output power, and further the electric power tool 100 is a small-sized and high-power tool, and the electric power tool has a higher performance. In some embodiments, the ratio of the input power to the motor 12 to the height L1 of the head housing 112 in the direction of the first axis 102 is greater than or equal to 5.5 watts per millimeter and less than or equal to 8.5 watts per millimeter.

The power tool 100 also includes a fan 15, the fan 15 being disposed within the head housing 112. When the fan 15 rotates, a heat radiation airflow for radiating heat of the motor 12 is generated in the housing 11. The housing 11 is also formed with an airflow inlet 113 and an airflow outlet 114, the airflow inlet 113 being provided at the joint portion 111b of the handle housing 111. A battery pack circuit board 161 and a battery pack terminal 162 are provided at the joint portion 111b, so that the heat dissipation airflow can dissipate the heat of the electronic component at the joint portion 111 b. The airflow outlet 114 is provided on the head housing 112, and in particular, the airflow outlet 114 is formed on the middle housing 112c, so that the heat dissipation airflow can dissipate the heat of the motor 12. The power tool 100 also includes a motor circuit board 163 electrically connected to the motor 12, the circuit board being disposed within the handle housing 111. Further, the circuit board is disposed at the grip portion 111 a. The heat dissipation airflow enters the first accommodating chamber 111e from the airflow inlet 113, then sequentially flows through the battery pack circuit board 161 and the motor circuit board 163, then enters the second accommodating chamber 112a, flows through the motor 12 from the upper side of the motor 12 along the first axis 102 direction, and finally flows out of the housing 11 from the airflow outlet 114 after flowing through the fan 15. The heat dissipating airflow can flow from inside the motor 12 and outside the motor 12, respectively, as it flows through the motor 12. The gaps between the coil windings 123 of the stator core 122 allow a cooling airflow to flow from the interior of the motor 12 through the motor 12. A gap is provided between the inner wall of the head housing 112 and the stator core 122 of the motor 12, and the gap allows a heat-dissipating airflow to flow through the motor 12 from the outside of the motor 12.

The motor 12 further includes: the first weight 128 and the second weight 129, and the first weight 128 and the second weight 129 are each mounted to the motor shaft 121 to adjust the balancing performance of the motor shaft 121. The first weight 128 is disposed at an upper side of the stator core 122, the second weight 129 is disposed at a lower side of the stator core 122, and the first weight 128 and the second weight 129 are further disposed between the first bearing 126 and the second bearing 127.

As shown in fig. 3 and 6, the fan 15 is disposed in the upper accommodation chamber 112e, and the fan 15 includes: mounting portion 151 and blade portion 152. As shown in fig. 6 and 11, the mounting portion 151 is used to mount the fan 15 to the motor shaft 121 so that the fan 15 can rotate together with the motor shaft 121, and the fan blade portion 152 includes a plurality of fan blades 152 a. Specifically, the mounting portion 151 is disposed between the first bearing 126 and the second bearing 127, and the mounting portion 151 is also disposed between the stator core 122 and the second bearing 127. The mounting portion 151 is mounted to the second weight 129, and the mounting portion 151 is fitted around the outer wall of the second weight 129, so that the height of the whole of the fan 15 and the second weight 129 can be reduced. The fan blade portion 152 is sunk with respect to the mounting portion 151, and the plurality of fan blades 152a are distributed at least partially in the circumferential direction around the first bearing 126. Specifically, the fan blade portion 152 is formed with a central region around which the second bearing 127 is at least partially located. Thus, the dimension L3 of the second weight 129, the fan 15, and the second bearing 127 in the direction along the first axis 102 is 13 mm or more and 21 mm or less. Further, the dimension L3 of the second weight 129, the fan 15, and the second bearing 127 in the direction along the first axis 102 is equal to or greater than 14 mm and equal to or less than 20 mm, so that the motor 12 can be downsized.

The first bracket 124 is formed with a first through hole 124a around the motor shaft 121, the motor shaft 121 passes through the first through hole 124a, the first weight 128 is disposed in the first through hole 124a, and a part of the first bearing 126 is disposed in the first through hole 124a, so that the size of the whole of the first bearing 126 and the first bracket 124 in the direction of the first axis 102 is smaller than the sum of the size of the first bearing 126 in the direction and the size of the first bracket 124 in the direction, thereby allowing the first bearing 126 and the first bracket 124 to at least partially overlap, and further allowing the size of the motor 12 in the direction of the first axis 102 to be reduced, which is advantageous for miniaturization of the head housing 112.

The second bracket 125 forms a second through hole 125a around the motor shaft 121, the motor shaft 121 passes through the second through hole 125a, a portion of the second weight 129 is disposed in the second through hole 125a, a portion of the mounting portion 151 also protrudes into the second through hole 125a, and the fan blade portion 152 is disposed at a lower side of the second bracket 125. In this way, the whole of the second weight 129, the fan 15, and the second bearing 127 can be overlapped with a part of the second bracket 125, which is more advantageous for reducing the size of the motor 12 in the direction of the first axis 102.

The motor 12 also includes a terminal assembly 12a, the terminal assembly 12a for coupling power to the coil winding 123. The motor circuit board 163 is disposed in the handle case 111, the motor circuit board 163 is connected to the terminal assembly 12a through the wire 164, and the terminal assembly 12a is connected to the coil winding 123, thereby achieving electrical connection of the motor 12 and the motor circuit board 163. The terminal assembly 12a is disposed on the side wall of the stator core 122, which makes it possible to reduce the size of the motor 12 in the direction along the first axis 102. The terminal assembly 12a is also disposed at the junction of the head housing 112 and the handle housing 111, that is, the terminal assembly 12a is disposed at the junction of the first accommodating chamber 111e and the second accommodating chamber 112a, and the terminal assembly 12a is mainly located within the second accommodating chamber 112 a.

The height L1 of the head casing 112 in the direction of the first axis 102 is equal to or greater than 70 mm and equal to or less than 90 mm by the arrangement and the position of each part in the head casing 112. Further, the height L1 of the head shell 112 in the direction of the first axis 102 is greater than or equal to 75 mm and less than or equal to 85 mm, so that the size of the head shell 112 is reduced to the maximum under the condition that the holding portion 111a is set to be thin, the holding by a user is facilitated, the size of the whole machine is also reduced, the head shell is conveniently used for observing accessories on the head, and the reliability of operation is improved.

In the first accommodation chamber 111e surrounded by the handle housing 111, a motor circuit board 163 and a wire 164 are mainly disposed. A battery pack circuit board 161 for connecting a battery pack and a switch assembly 165 are further provided in the first receiving chamber 111 e. The ratio of the total weight W1 of the handle shell 111 and the first type of element at least partially disposed within the handle shell 111 to the total weight W2 of the head shell 112 and the second type of element at least partially disposed within the head shell 112 is greater than or equal to 0.4 and less than or equal to 0.55. Further, the ratio of the total weight W1 of the handle housing 111 and the first type of element at least partially disposed within the handle housing 111 to the total weight W2 of the head housing 112 and the second type of element at least partially disposed within the head housing 112 is greater than or equal to 0.43 and less than or equal to 0.51. Wherein the first type of part comprises: the parts completely located in the handle housing 111 and the parts partially located in the handle housing 111, specifically, the first type of parts may include a motor circuit board 163, a wire 164, a battery pack circuit board 161, etc. located in the first receiving cavity 111e, and may further include a switch assembly 165, a battery pack terminal 162, etc. partially located in the first receiving cavity 111 e. The second type of part includes: the parts located entirely within the head housing 112 and the parts located partially within the head housing 112, and in particular, the second type of parts may include the motor 12, the reduction assembly 14, etc. located within the second receiving chamber 112a, and the output member 13 located partially within the second receiving chamber 112 a. The total weight W1 of the handle shell 111 and the parts at least partially positioned in the handle shell 111 is greater than or equal to 300 grams and less than or equal to 450 grams, and the total weight W2 of the head shell 112 and the parts at least partially positioned in the head shell 112 is greater than or equal to 800 grams and less than or equal to 900 grams. Thus, the weight of the middle part of the electric tool 100 is light, and the weight of the head part is not heavy, so that the gravity center G of the whole machine is positioned on the handle shell 111, and the balance of the electric tool 100 is improved. Specifically, the distance between the center of gravity G of the electric power tool 100 and the first axis 102 in the direction along the first straight line 101 is 100 mm or more and 125 mm or less.

The ratio of the dimension L4 of the grip 111a in the first straight line 101 direction to the dimension L5 of the handle case 111 in the first straight line 101 direction is 0.5 or more and 0.8 or less. Furthermore, the ratio of the dimension L4 of the holding portion 111a along the first straight line 101 to the dimension L5 of the handle housing 111 along the first straight line 101 is greater than or equal to 0.6 and less than or equal to 0.7, so that the length of the holding portion 111a is moderate, and the user can feel better in holding.

The reduction assembly 14 includes: a first gear 141 and a second gear 142, the first gear 141 being mounted to the motor shaft 121, the second gear 142 being mounted to the output member 13, the first gear 141 and the second gear 142 being engaged with each other. The gear ratio of the reduction unit 14 is 3 or more and 4 or less, and the load carrying capacity of the electric power tool 100 can be improved.

As shown in fig. 9 and 11, the fan blade portion 152 further includes: an upper cover plate 152b and a lower cover plate 152 c. The plurality of blades 152a are sequentially disposed around the mounting portion 151. The upper covering plate 152b covers the outer side of the upper edge of the fan blade 152a, and the lower covering plate covers the inner side of the lower edge of the fan blade 152 a. The heat dissipation airflow flows into the channel between two adjacent fan blades 152a from the area between the upper covering plate 152b and the mounting portion 151, and the lower covering plate 152c can reduce the heat dissipation airflow flowing downward out of the fan 15 after entering the channel, but guide the heat dissipation airflow to flow out of the fan 15 along the radial direction, thereby forming a centrifugal airflow. This improves the performance of the fan 15 while matching the structure of the fan 15 to that of the motor 12, thereby making the arrangement of the parts within the head housing 112 more compact.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It should be understood by those skilled in the art that the above embodiments do not limit the present invention in any way, and all technical solutions obtained by using equivalent alternatives or equivalent variations fall within the scope of the present invention.

Claims

1. A power tool, comprising:

an output member for outputting power;

a motor for driving the output member;

the speed reducing assembly is used for realizing power transmission between the motor and the output piece;

a housing including a handle housing and a head housing;

characterized in that, the motor includes:

a motor shaft rotatable about a first axis;

a stator core surrounding the motor shaft;

a first bearing mounted to the motor shaft and located at an upper side of the stator core;

a second bearing mounted to the motor shaft and located at a lower side of the stator core;

the handle shell comprises a holding part extending along a first straight line direction perpendicular to or obliquely intersecting with the first axis, the motor is arranged in the head shell, and the distance between the first bearing and the second bearing is greater than or equal to 28 mm and smaller than or equal to 42 mm.

2. The power tool of claim 1, further comprising:

a fan at least partially disposed within the head housing;

the fan includes a mounting portion for mounting the fan to the motor shaft, the mounting portion being disposed between the first bearing and the second bearing.

3. The power tool of claim 2, wherein the motor further comprises:

a counterbalance mounted to the motor shaft;

the mounting portion of the fan is mounted to the weight.

4. The power tool of claim 2, wherein the motor further comprises:

a counterbalance mounted to the motor shaft;

the balance weight is arranged on the lower side of the stator core;

the size of the balance weight, the fan and the second bearing in the first axial direction is larger than or equal to 13 mm and smaller than or equal to 21 mm.

5. The power tool of claim 2, wherein the mounting portion is disposed between the second bearing and the stator core.

6. The power tool of claim 5, wherein the fan further comprises:

a blade part including a plurality of blades;

the flabellum portion is relative the installation department sinks, and is a plurality of the flabellum is at least partly around the circumferencial direction of second bearing distributes.

7. The power tool of claim 1, wherein the motor further comprises:

a first bracket for supporting the stator core and at least partially disposed at an upper side of the stator core;

the dimension of the whole of the first bearing and the first bracket in the first axial direction is smaller than the sum of the dimension of the first bearing in the direction and the dimension of the first bracket in the direction.

8. The power tool of claim 1, wherein the motor further comprises:

the second bracket is used for supporting the stator core and is at least partially arranged at the lower side of the stator core;

the second bracket is surrounded by a through hole for the motor shaft to pass through, and the electric tool further comprises a fan mounted to the motor shaft, wherein at least part of the fan extends into the through hole.

9. The power tool of claim 1, wherein the motor further comprises:

a coil winding wound to the stator core;

a terminal assembly for coupling power to the coil winding;

the terminal assembly is disposed at a sidewall of the stator core.

10. The power tool according to claim 1, wherein a height of the head case in the first axial direction is 70 mm or more and 90 mm or less.

11. The power tool of claim 1, further comprising a circuit board electrically connected to the motor, wherein the output member is at least partially disposed within the head housing, wherein the circuit board is disposed within the handle housing, wherein the handle housing and the head housing are removably coupled, and wherein a ratio of a total weight of the handle housing and a first type of component at least partially disposed within the handle housing to a total weight of the head housing and a second type of component at least partially disposed within the head housing is greater than or equal to 0.4 and less than or equal to 0.55.

12. The power tool of claim 11, further comprising:

a battery pack detachably mounted to the handle housing;

in the first linear direction, a distance between the center of gravity of the electric power tool and the first axis is equal to or greater than 100 mm and equal to or less than 125 mm.