CN210610338U

CN210610338U - Long rod type electric tool

Info

Publication number: CN210610338U
Application number: CN201921321755.6U
Authority: CN
Inventors: 王浩; 山冈敏成; 聂方杰
Original assignee: Chevron HK Ltd
Current assignee: Nanjing Chervon Industry Co Ltd
Priority date: 2018-12-28
Filing date: 2019-08-14
Publication date: 2020-05-26
Anticipated expiration: 2029-08-14
Also published as: CN210610337U; CN111373918A; CN211020028U

Abstract

The utility model provides a stock class electric tool, include: a connecting rod having a front end and a rear end in a length direction thereof; the power supply device is arranged at the rear end of the connecting rod; an execution device; the motor is used for driving the executing device to rotate; the long-rod-type electric tool further includes: a transmission device; the motor includes: a rotor shaft rotatable about a first axis; a rotor sleeve mounted to the rotor shaft and configured to rotate in synchronization with the rotor shaft, both ends of the rotor shaft passing through the rotor sleeve; a stator core at least partially disposed within the rotor sleeve; a stator coil wound around the stator core; the rotor shaft extends into a space surrounded by the device shell and is connected with the speed reducing mechanism. The utility model provides a long rod type electric tool, which is a grass trimmer with small size, light weight and good performance.

Description

Long rod type electric tool

Technical Field

The utility model relates to a garden long-rod electric tool, in particular to a grass trimmer.

Background

A lawn mower, which is a garden tool, is generally a long-pole electric tool, and is widely favored by users. However, for the existing grass mower, the grass mower and other tools are mostly inner rotor or outer rotor large motor direct-drive grass mowing heads, and the problems of low rotating speed, large size of a low-speed motor, heavy weight, high price and the like can be caused. The volume of the whole grass trimmer is larger, which is not beneficial to reducing the weight of the whole grass trimmer, so that the storage and the transportation of a user are inconvenient; generally, the motor sets up in the head of beating grass, the great optimization of limiting the volume of the head of beating grass of the volume of motor, because of the difficult reduction of the head volume of beating grass, and the motor that sets up in the head of beating grass has certain weight, further increase the weight of the head of beating grass, make the user when the machine is beaten grass in the operation, the weight of the head one end of beating grass is heavier, load when having increased the user and controled, make the user be difficult to last work for a long time, the availability factor of using the machine of beating grass has been reduced.

Disclosure of Invention

In order to solve the defects of the prior art, the utility model aims to provide a long rod electric tool with small size, light weight and good performance.

In order to solve the utility model discloses an object provides a stock class electric tool, include: a connecting rod having a front end and a rear end in a length direction thereof; the power supply device is arranged at the rear end of the connecting rod; the actuating device is used for installing an actuating element and is arranged at the front end of the connecting rod; the motor is used for driving the executing device to rotate; the long-rod-type electric tool further includes: a transmission device comprising a speed reducing mechanism for realizing power transmission between the motor and the executing device and a device shell for accommodating at least part of the speed reducing mechanism; the motor includes: a rotor shaft rotatable about a first axis; a rotor sleeve mounted to the rotor shaft and configured to rotate in synchronization with the rotor shaft, both ends of the rotor shaft passing through the rotor sleeve; a stator core at least partially disposed within the rotor sleeve; a stator coil wound around the stator core; the rotor shaft extends into a space surrounded by the device shell and is connected with the speed reducing mechanism.

Optionally, the diameter D1 of the rotor sleeve is set to be 40mm or less, and the ratio of the output power P of the motor to the diameter D1 of the rotor sleeve is 80W/cm or more and 160W/cm or less.

Optionally, the motor is a brushless motor, and the diameter D1 of the rotor sleeve is less than or equal to 35 mm.

Optionally, the diameter D1 of the rotor sleeve is 35 mm; the ratio of the output power P of the motor to the volume V of the motor is more than or equal to 11W/cm³And is less than or equal to 35W/cm³。

Optionally, a ratio of the rotation speed of the rotor shaft to the rotation speed of the actuator is defined as a reduction ratio R of the reduction mechanism, and the reduction ratio R of the reduction mechanism is greater than or equal to 3.5 and less than or equal to 7.

Optionally, the rotation speed of the rotor shaft is greater than or equal to 24000 rpm.

Optionally, the rotation speed of the executing device is greater than or equal to 4000rpm and less than or equal to 6500 rpm.

Optionally, the long-rod electric tool further includes: a front end housing including a first receiving portion for receiving at least a portion of the motor and a second receiving portion for receiving at least a portion of the transmission;

wherein a connection of the first receiving portion and the second receiving portion forms a stepped structure.

Optionally, the speed reducing mechanism further comprises: the driving shaft is connected with the executing device to drive the executing device to rotate; the driving shaft can rotate by taking a second axis as an axis; the first axis and the second axis are parallel to each other, and the distance between the first axis and the second axis is greater than or equal to 10mm and less than or equal to 25 mm.

Optionally, the speed reducing mechanism further comprises: a gear mounted to the driving shaft to receive power output from the motor; two bearings installed to the driving shaft and respectively provided at both sides of the gear.

Optionally, the executing device is a grass cutting head for cutting grass.

The utility model discloses an useful part lies in: the long-rod electric tool is small in size, light in weight and good in performance.

Drawings

Fig. 1 is a perspective view of a long-pole electric tool according to an embodiment of the present invention;

FIG. 2 is a plan view of a portion of the front end mechanism of FIG. 1;

FIG. 3 is a cross-sectional view of the structure shown in FIG. 2;

FIG. 4 is a plan view of the motor, transmission, fan and grass-mowing head of FIG. 3;

FIG. 5 is a cross-sectional view of the structure shown in FIG. 4;

FIG. 6 is an exploded view of the structure shown in FIG. 4;

FIG. 7 is a perspective view of another angle of the structure shown in FIG. 6;

fig. 8 is an enlarged view of a part of the structure shown in fig. 5.

Detailed Description

In an embodiment of the present invention, a long-rod electric tool is provided, taking a grass trimmer 100 as an example, and fig. 1 is a perspective view of the long-rod electric tool according to an embodiment of the present invention; a lawnmower 100, as shown in fig. 1, is used by a user to cut grass, trim vegetation, and the like. The grass trimmer 100 comprises a power supply device 12 and an actuating device 13, wherein the actuating device 13 is used for installing an actuating element, and an electric tool outputs work through the actuating element. The long rod type electric tool further comprises a connecting rod 11 and a transmission device 15, wherein the connecting rod 11 is used for connecting a power supply device 12 and an execution device 13 and is convenient for a user to operate the long rod type electric tool, the connecting rod 11 is defined to have a front end and a rear end in the length direction, generally, the power supply device 12 is arranged at the rear end of the connecting rod 11, and the execution device 13 is arranged at the front end of the connecting rod 11.

FIG. 2 is a plan view of a portion of the front end mechanism of FIG. 1; FIG. 3 is a cross-sectional view of the structure shown in FIG. 2; FIG. 4 is a plan view of the motor, transmission, fan and grass-mowing head of FIG. 3; referring to fig. 3, the long-pole type electric tool further includes a motor 141, and the motor 141 drives the actuator 13 to rotate; referring to fig. 4, the transmission 15 includes a speed reducing mechanism 151 for transmitting power between the motor 141 and the actuator 13, and a device case 153 for accommodating at least a part of the speed reducing mechanism 151.

FIG. 5 is a cross-sectional view of the structure shown in FIG. 4; referring to fig. 2 to 5, the motor 141 includes a rotor shaft 141c rotatable about the first axis 102, and further includes a rotor sleeve 141d, a stator core 141a, and a stator coil 141 b; a rotor sleeve 141d is mounted to the rotor shaft 141c and rotates in synchronization with the rotor shaft 141c, and both ends of the rotor shaft 141c pass through the rotor sleeve 141 d; the stator core 141a is at least partially disposed within the rotor sleeve 141d and serves to wind the stator coil 141 b. The rotor shaft 141c extends into a space surrounded by the device case 153 and is connected to the reduction mechanism 151; in the utility model, the proposed volume is less than 45 cm³The ratio of the maximum output power P of the motor 141 to the volume V of the motor 141 is more than or equal to 11W/cm³。

Further, the transmission device 15 includes a driving shaft 152, and the driving shaft 152 is connected to the actuator 13 to drive the actuator 13 to rotate.

In order to reduce the volume of the motor 141, reduce the weight of the motor 141, thereby optimizing the size of the whole machine, facilitating the user to operate the long-rod type electric tool, and reduce the size of the diameter D1 of the rotor sleeve 141D, thereby reducing the volume and weight of the motor 141. Therefore, while the maximum output power of the motor 141 is satisfied, the diameter of the rotor sleeve 141D is reduced such that the diameter D1 of the rotor sleeve is 40mm or less and the ratio of the maximum output power P of the motor to the volume V of the motor is 15W/cm or more³And is less than or equal to 35W/cm³Thereby ensuring that the weight of the motor 141 is reduced effectively for the long-rod type electric tool because the motor 141 is provided at the front end of the link 11The front end is light in weight, and a user can lift the whole machine in a labor-saving manner, so that the fatigue of the user in operating the long-rod electric tool is reduced, the time for the user to continuously operate the electric tool is effectively prolonged, and the operation comfort and the working efficiency are improved.

Further, the diameter D1 of the rotor sleeve 141D is embodied to be 35 mm, and the ratio of the maximum output power P of the motor 141 to the volume V of the motor 141 is 15W/cm or more³Less than or equal to 25W/cm³Therefore, the volume of the motor 141 is reduced under the condition that the maximum output power of the motor 141 meets the working requirement, so that the size of the whole machine is optimized, and the operation of a user is facilitated. Preferably, the motor 141 is selected as a brushless motor.

The long-rod electric tool is exemplified by a grass trimmer 100, the grass trimmer 100 comprises a housing assembly, a power supply device 12, a motor 141, an actuating device 13 and a connecting rod 11, and the power supply device 12 is used for providing a power source for the motor 141. The actuating device 13 is implemented as a grass cutting head 131 and is connected to the front end of the connecting rod 11, the power supply device 12 is implemented as a battery pack and is connected to the rear end of the connecting rod 11 for supplying electric energy, the motor 141 is connected with the grass cutting head 131 and drives the grass cutting head 131 to operate, the grass cutting head 131 is provided with an actuating element, and in the grass cutting machine 100, the actuating element is generally implemented as a grass cutting rope 132, and the grass cutting rope 132 is driven by the grass cutting head 131 to rotate. The lawn mower 100 further comprises a transmission device 15, wherein the transmission device 15 comprises a speed reducing mechanism 151 for realizing power transmission between the motor 141 and the actuating device 13.

The housing assembly includes a front housing 142 and a device housing 153, the front housing 142 fixedly supporting the grass-mowing head 131, the motor 141 being disposed within the grass-mowing head 131 and supported by the motor 141, the device housing 153 accommodating at least a part of the reduction mechanism 151. The front end housing 142 is used to mount and house the grass mowing cord 132. The grass mowing rope 132 is partially stored inside the grass mowing head 131, and a part of the grass mowing rope extends out of the grass mowing head 131 to be used for cutting vegetation when the grass mowing head 131 rotates, generally, the front end shell 142 comprises a connecting hole, and the grass mowing rope 132 extends out of the grass mowing head 131 from the inner part of the grass mowing head 131 through the connecting hole.

The grass mowing head 131 has a winding mode and a grass mowing mode, the grass mowing head 131 further comprises a spool arranged in the front end shell 142 and an operating piece supported by the front end shell 142, the spool is arranged in an accommodating space formed by the front end shell 142 in a surrounding mode, the spool at least comprises a winding portion used for winding the grass mowing rope 132, and the operating piece is connected with the spool and at least partially arranged outside the front end shell 142, so that a user can operate the operating piece to enable the spool to rotate in a first direction relative to the front end shell 142, the grass mowing rope 132 is wound on the spool, and the winding process is completed; when the user controls the grass trimmer 100 to start the grass trimming mode, the motor 141 drives the spool to rotate in the second direction, so that the grass trimmer 100 is in the grass trimming mode, and the grass trimming head 131 drives the grass trimming rope 132 to rotate at a high speed, so that the aim of cutting lawns and weeds is fulfilled. The first direction is opposite to the second direction, and the second direction is clockwise if the first direction is counterclockwise. In another embodiment, the motor 141 and the front housing 142 are connected, and the operation member and the front housing 142 can rotate synchronously, and the user can operate the operation member to rotate the front housing 142, so that the spool and the front housing 142 rotate relatively, and the grass mowing cord 132 is wound on the spool.

The motor 141 includes a rotor shaft 141c rotatable about the first axis 102, and a rotor sleeve 141d rotatable about the rotor shaft 141c, the rotor sleeve 141d being mounted to the rotor shaft 141c to rotate in synchronization therewith, and having both ends of the rotor shaft 141c passing through the rotor sleeve 141 d; and further includes a stator core 141a provided in the rotor sleeve 141d, and a stator coil 141b wound around the stator core 141 a. Diameter D1 less than or equal to 35 millimeters of rotor sleeve 141D, like this, compare in current large-size motor 141, the utility model provides a rotor sleeve 141D's diameter D1's size is less, thereby make motor 141's volume less, weight is also lighter, and motor 141 is satisfying under the prerequisite that maximum output meets the demands, reduce motor 141's volume as far as possible, thereby can reduce the size of well front end casing 142, and can make the holistic weight of grass mowing head 131 lighter, thereby the user can be very laborsaving lift grass mowing head 131 of the front end of grass mowing machine 100, and then make the user can not feel very tired after long-time work yet, the efficiency of work has been improved.

Further, the diameter D1 of rotor sleeve 141D is 35 millimeters; the ratio of the maximum output power P of the motor 141 to the volume V of the motor 141 is not less than 15W/cm³And is less than or equal to 25W/cm³. Thus, the volume of the motor 141 can be further reduced when the maximum output power of the motor 141 meets the working requirement, and the performance of the grass trimmer 100 can be further optimized.

The transmission 15 is used for transmitting power between the motor 141 and the grass-mowing head 131. The speed reduction mechanism 151 can reduce the rotational speed output by the rotor shaft 141c and output the reduced rotational speed to the drive shaft 152, thereby improving the output torque of the grass cutting head 131 and improving the grass cutting capability of the grass cutter 100. Because reduction gears 151's setting makes the utility model discloses a grass mower 100 can adopt small-size, high rotational speed motor 141 to can reach the effect that grass mower 100's weight was reduced, adopt such high rotational speed motor 141 can also improve grass mower 100's the efficiency of beating grass simultaneously.

In the present embodiment, the ratio of the rotation speed of the rotor shaft 141c to the rotation speed of the grass-mowing head 131 is defined as the reduction ratio R of the reduction mechanism 151, the reduction ratio R of the reduction mechanism 151 is equal to or greater than 3.5 and equal to or less than 7, and further, the reduction ratio R of the reduction mechanism 151 is preferably equal to or greater than 4 and equal to or less than 4.5. On the one hand, the reduction mechanism 151 with the reduction ratio of such a size can be realized easily, and on the other hand, the reduction mechanism 151 with the reduction ratio of such a size is adopted, so that the grass trimmer 100 with a reasonable size and a high rotating speed can be selected by people, the size of the grass trimmer 100 is reduced while the performance of the grass trimmer 100 is met, the cost is effectively reduced, and the grass trimmer is convenient for users to operate and hold. In the present embodiment, the rotation speed of the rotor shaft 141c is equal to or greater than 24000rpm, and the rotation speed of the grass-mowing head 131 is equal to or greater than 4000rpm and equal to or less than 6500 rpm, that is, the rotation speed of the driving shaft 152 is equal to or greater than 4000rpm and equal to or less than 6500 rpm.

The driving shaft 152 is rotatable about the second axis 103; the first axis 102 and the second axis 103 are parallel to each other, and a distance between the first axis 102 and the second axis 103 is 10mm or more and 25mm or less. In the grass trimmer 100, the driving shaft 152 is connected with the grass cutting head 131 to drive the grass cutting head 131 to rotate so as to realize the grass cutting function, the driving shaft 152 can rotate by taking the second axis 103 as an axis, and the second axis 103 is parallel to the first axis 102, so that the driving shaft 152 and the rotor shaft 141c are relatively parallel, and the size of the actuating device 13 in the direction of the first axis 102, namely the height of the actuating device 13, is reduced. In the lawnmower 100, the drive shaft 152 and the rotor shaft 141c are made parallel to reduce the size of the grass cutting head 131, thereby reducing the height of the grass cutting head 131.

FIG. 6 is an exploded view of the structure shown in FIG. 4; FIG. 7 is a perspective view of another angle of the structure shown in FIG. 6; referring to fig. 6 and 7, specifically, the device housing 153 is connected to the front end housing 142 and disposed in the front end housing 142, and the device housing 153 accommodates the speed reducing mechanism 151 to protect the speed reducing mechanism 151, so that the service life of the transmission device 15 can be effectively prolonged. The device case 153 includes a case 153a and a top cover 153b, the top cover 153b is attached to an upper end of the case 153a, and the case 153a surrounds to form a receiving chamber 153c for receiving the speed reducing mechanism 151. Optionally, the case 153a is made of plastic, so that the case 153a is light in weight, thereby further reducing the weight of the actuator 13, reducing the operation load of the user, improving the work efficiency of the user, and making the manufacturing process of the case 153a simple and easy to mold. The top cover 153b is coupled to an upper end of the case 153a and covers at least a portion of the case 153a that is open upward.

The top cover 153b is made of a metal material, so that the top cover 153b is a metal member, and because the metal material has excellent heat conductivity, heat generated inside the device case can be effectively conducted out through the top cover 153 b. Extending from the top cover 153b at least partially in a plane perpendicular to the first axis 102, such that heat within the device housing 153 can be dissipated through the top cover 153 b. In this embodiment, the front housing 142 includes a heat dissipating portion 142a at least partially facing the top cover 153b, the heat dissipating portion 142a extends in another plane perpendicular to the first axis 102, at least a portion of the top cover 153b faces the heat dissipating portion 142a, and the top cover 153b is closer to the heat dissipating portion 142a, thereby improving the heat dissipating effect. Because the motor size reduces, its thermal diffusivity can reduce thereupon, overheated motor can the deratization even, consequently need promote the heat-sinking capability of motor, just can guarantee the output and other basic performance of motor, through setting up the whole promotion of top cap and radiating part to the radiating effect, in order to guarantee the utility model provides a less motor operation of size normally can not be along with the reduction of motor size, the performance also reduces thereupon.

The top cover 153b is further formed with a stator holder portion 141e for supporting the stator core 141a, and in one connection, the stator holder portion 141e is implemented as a sleeve and is engaged with the stator core 141a through the stator holder portion 141e to fixedly support the stator core 141 a. In order to match the connection relationship between the motor 141 and the reduction mechanism 151, the stator holder portion 141e is connected to the stator core 141a at a position corresponding to the first gear 151a, so that the rotor shaft 141c and the first gear 151a are connected to rotate synchronously.

Further, the front housing 142 is configured to receive at least a portion of the actuator 13. The front end housing 142 includes a first receiving portion 1421 and a second receiving portion 1422, the first receiving portion 1421 is configured to receive at least a portion of the motor 141, and the second receiving portion 1422 is configured to receive at least a portion of the transmission 15. Compared with the conventional electric tool, since the size of the motor 141 is reduced, the size of the corresponding first accommodating part 1421 accommodating the motor 141 can be reduced, the diameter D1 of the rotor sleeve 141D of the motor 141 is smaller than 35 mm, so that the size of the projection of the motor 141 in a plane perpendicular to the first axis 102 is smaller than the size of the projection of the speed reducing mechanism 151 in the plane, in order to match the connection relationship between the motor 141 and the transmission 15, the first accommodating part 1421 and the second accommodating part 1422 are connected, and because of the relative sizes of the motor 141 and the transmission 15, the connection part between the first accommodating part 1421 and the second accommodating part 1422 forms a step structure.

The second accommodating part 1422 extends from the first accommodating part 1421 along the first axis 102 direction, and partially exceeds the first accommodating part 1421 along a direction perpendicular to the first axis 102, so that a projection of the second accommodating part 1422 in the first axis 102 direction coincides with a projection of the second accommodating part 1422 on the first axis 102, and partially exceeds a projection of the second accommodating part 1422 on the first axis 102, thereby forming a step structure at a connection of the first accommodating part 1421 and the second accommodating part 1422. The design of the front housing 142 is not only beneficial to further reducing the size of the front housing, but also enables the first accommodating part 1421 and the second accommodating part 1422 to be close to the motor 141 and the transmission 15 arranged in the front housing, so as to be beneficial to heat dissipation of the motor 141 and the transmission 15, and heat generated by the motor 141 and the transmission 15 in the operation process can be directly dissipated from the first accommodating part 1421 and the second accommodating part 1422 close to the front housing, so that the motor or the transmission is prevented from being overheated to influence the operation performance of the grass trimmer; meanwhile, the stepped arrangement of the first accommodating part 1421 and the second accommodating part 1422 makes the overall arrangement more compact, and effectively reduces the size and weight of the front-end device, thereby facilitating the operation of a user and reducing the manufacturing cost.

Further, the front housing 142 may further be configured to include a first receiving portion 1421, a second receiving portion 1422, and a third receiving portion 1424, where the first receiving portion 1421 is configured to receive at least a portion of the motor, the second receiving portion 1422 is configured to receive at least a portion of the transmission, and the third receiving portion 1424 is configured to receive a mounting fan. Compared with the conventional electric tool, as the size of the motor is reduced, the size of the corresponding first accommodating part 1421 for accommodating the motor can be reduced, the diameter D1 of the rotor sleeve of the motor is set to be less than 40mm, so that the size of the projection of the motor in the plane perpendicular to the first axis is smaller than the size of the projection of the speed reducing mechanism in the plane, in order to match the connection relationship between the motor and the transmission, the first accommodating part 1421 and the second accommodating part 1422 are connected, and because of the relative sizes of the motor and the transmission, the connection between the first accommodating part 1421 and the second accommodating part 1422 forms a step structure, and further, the connection between the third accommodating part 1424 and the second accommodating part 1422 forms a step structure.

The second receiving portion 1422 extends from the first receiving portion 1421 along a first axis direction, and partially exceeds the first receiving portion 1421 along a direction perpendicular to the first axis, so that a projection of the second receiving portion 1422 in the first axis direction coincides with a projection of the second receiving portion 1422 in the first axis direction, and partially exceeds a projection of the first receiving portion 1421 in the first axis direction, thereby forming a step structure at a connection of the first receiving portion 1421 and the second receiving portion 1422. Furthermore, the third accommodating portion 1424 extends from the second accommodating portion 1422 along the first axis direction, and partially exceeds the second accommodating portion 1422 and the first accommodating portion 1421 along a direction perpendicular to the first axis, so that a projection of the third accommodating portion 1424 in the first axis direction coincides with a projection of the second accommodating portion 1422 in the first axis direction, and partially exceeds the second accommodating portion 1422, and the design of the front end housing 142 is not only beneficial to further reducing the size of the front end housing, but also beneficial to heat dissipation of the motor and the transmission device because the first accommodating portion 1421 and the second accommodating portion 1422 are close to the motor and the transmission device arranged inside the front end housing, and the whole arrangement is more compact.

For cooperation with the motor 141, the first accommodation part 1421 includes a first surrounding part 1423 surrounding the first axis 102; the first surrounding portion 1423 is used for accommodating the motor 141, and as the size of the motor decreases, the volume of the first surrounding portion 1423 may decrease with the decrease of the size of the motor, and the radius of the first surrounding portion 1423 may be at least 18mm, and further, in order to ensure that the size of the first surrounding portion 1423 has a small influence on the size optimization of the front end device, it is preferable that the radius of the first surrounding portion 1423 is not greater than 25.5 mm.

Further, the transmission device 15 includes a driving shaft 152, and the driving shaft 152 is connected to the actuator 13 to drive the actuator 13 to rotate. The driving shaft 152 is rotatable about the second axis 103 such that the second axis 103 is parallel to the first axis 102, and the driving shaft 152 and the rotor shaft 141c are relatively parallel, thereby reducing the size of the actuator 13 in the direction of the first axis 102, i.e., reducing the height of the actuator 13.

Specifically, in the present embodiment, the distance between the second axis 103 of the rotation of the driving shaft 152 and the first axis 102 of the rotation of the rotor shaft 141c is greater than or equal to 10mm and less than or equal to 25mm, and further, the distance between the second axis 103 of the rotation of the driving shaft 152 and the first axis 102 of the rotation of the rotor shaft 141c is greater than or equal to 15mm and less than or equal to 22mm, which can avoid the dimension of the transmission device 15 in the direction perpendicular to the first axis 102 from being too long, so that the overall size of the actuator 13 is small. That is, the size of the grass cutting head 131 in the direction perpendicular to the first axis 102 is reduced, thereby reducing the weight of the front end of the connecting rod 11 and improving the use comfort.

A reduction mechanism 151 is provided in the device case 153, the reduction mechanism 151 further including gears and bearings, the gears being mounted to the drive shaft 152 to receive power output from the motor 141; alternatively, the number of bearings is generally two, mounted to the drive shaft 152 and disposed on either side of the gear. The reduction mechanism 151 is provided in the device case 153, and optionally, the reduction mechanism 151 includes first and

second gears

151a and 151b, and first and

second bearings

151c and 151d, the first gear 151a being mounted to the rotor shaft 141c and the first gear 151a rotating synchronously with the rotor shaft 141c, the second gear 151b being mounted to the drive shaft 152 and the second gear 151b rotating synchronously with the drive shaft 152; the first gear 151a and the second gear 151b are engaged with each other, and in particular, the second gear 151b is axially engageable with the first gear 151a at an outer side of the first gear 151 a; that is, the first gear 151a and the second gear 151b are capable of being in external mesh. The ratio of the number of teeth of the second gear 151b to the number of teeth of the first gear 151a is 3.5 or more and 7 or less, so that the reduction ratio R of the reduction mechanism 151 is 3.5 or more and 7 or less. Further, the ratio of the number of teeth of the second gear 151b to the number of teeth of the first gear 151a is 4 or more and 4.5 or less. So that the reduction ratio R of the reduction mechanism 151 is 4 or more and 4.5 or less. Further, the number of teeth of the first gear 151a is 6 or more and 12 or less, and the number of teeth of the second gear 151b is 24 or more and 50 or less. The first and

second bearings

151c and 151d are each mounted to the driving shaft 152, and the first and

second bearings

151c and 151d are respectively disposed at both sides of the second gear 151 b. The reduction is performed by the cooperation of the first gear and the second gear 151b, the manufacturing cost can be effectively reduced, and the size arrangement of the reduction mechanism 151 is optimized, so that the whole volume of the reduction mechanism 151 is reduced.

Further, when the diameter D1 of the rotor sleeve 141D is less than or equal to 35 mm, and the deceleration mechanism 151 is engaged externally, the cutting diameter D2 of the grass cutting rope mounted on the grass cutting head can be 300-400mm, and the maximum linear distance between the two ends of the grass cutting rope 132 mounted on the grass cutting head 131 is defined as the cutting diameter D2 of the grass cutting head 131; when the grass cutting head 131 rotates to perform the grass cutting head 131, the ratio of the cutting diameter D2 of the grass cutting head to the diameter D1 of the rotor sleeve is greater than or equal to 8.5 and less than or equal to 13. On the premise of meeting the requirement of the cutting diameter of the grass cutting head 131, the size of the motor 141 is reduced, the size of a front-end device is reduced, and the operation experience of a user is optimized.

Further, in order to fit the size of the motor 141, the rotation speed of the corresponding rotor shaft 141c is 24000rpm or more because the reduction ratio R of the reduction mechanism 151 is 3.5 or more and 7 or less or the reduction ratio R of the reduction mechanism 151 is 4 or more and 4.5 or less. On the one hand, the reduction mechanism 151 with the reduction ratio of such a size can be realized easily, and on the other hand, the reduction mechanism 151 with the reduction ratio of such a size is adopted, so that the grass trimmer 100 with a reasonable size and a high rotating speed can be selected by people, the size of the grass trimmer 100 is reduced while the performance of the grass trimmer 100 is met, the cost is effectively reduced, and the grass trimmer is convenient for users to operate and hold. In the present embodiment, correspondingly, the rotation speed of the grass-mowing head 131 is greater than or equal to 4000rpm and less than or equal to 6500 rpm, that is, the rotation speed of the driving shaft 152 is greater than or equal to 4000rpm and less than or equal to 6500 rpm.

The ratio of the weight W1 of the motor 141 to the weight W2 of the grass cutting head 131 is more than or equal to 0.05 and less than or equal to 0.6.

Because the specification of the motor 141 is selected such that the diameter D1 of the rotor sleeve 141D is less than 35 mm, the weight thereof is reduced as the volume thereof is reduced, and by adjusting the weight ratio of the motor 141 and the grass-mowing head 131, the grass-mowing head 131 is still light in weight and easy to hold and control in a state where the motor 141 is installed. Furthermore, the ratio of the weight W1 of the motor 141 to the weight W2 of the grass cutting head 131 is greater than or equal to 0.05 and less than or equal to 0.6.

Further, the ratio of the weight W1 of the motor 141 to the weight W2 of the grass-mowing head 131

0.1 to 0.4 inclusive. The ratio of the weight W1 of the motor 141 to the weight W2 of the grass cutting head 131 is controlled to be 0.1-0.4, the weight of the grass cutting head 131 is reduced on the premise that the motor 141 can provide required torque, the performance of the grass cutting machine is guaranteed, the weight is reduced reasonably, and the grass cutting machine is convenient to hold and use by a user.

The maximum output of the motor 141 can be set to 300W at least by setting the above specifications of the motor 141 and the reduction mechanism 151, so that the diameter of the rotor sleeve of the motor 141 is set to be less than 40mm and the ratio of the maximum output of the motor 141 to the diameter D1 of the rotor sleeve is 80W/cm or more in this embodiment.

Alternatively, the rotation axis of the driving shaft 152 and the first axis 102 are arranged in parallel, the driving shaft 152 is arranged to rotate around the second axis 103, and the second axis 103 and the first axis 102 are arranged in parallel, so that the driving shaft 152 and the rotor shaft 141c are relatively parallel, and the size of the actuator 13 in the direction of the first axis 102, that is, the height of the actuator 13, is reduced. In the lawnmower 100, the drive shaft 152 and the rotor shaft 141c are made parallel to reduce the size of the grass cutting head 131, thereby reducing the height of the grass cutting head 131.

Specifically, the distance between the second axis 103 of the rotation of the driving shaft 152 and the first axis 102 of the rotation of the rotor shaft 141c is greater than or equal to 10mm and less than or equal to 25mm, and further, the distance between the second axis 103 of the rotation of the driving shaft 152 and the first axis 102 of the rotation of the rotor shaft 141c is greater than or equal to 15mm and less than or equal to 22mm, so that the transmission device 15 is prevented from being too long in the direction perpendicular to the first axis 102, and the overall size of the actuator 13 is small.

The grass trimmer 100 further comprises a fan assembly 16, and optionally, the fan assembly 16 is arranged between the transmission device 15 and the grass trimmer head 131; the fan assembly 16 includes a fan 161 and a connecting member, the fan 161 is connected to the grass cutting head 131 or the driving shaft 152 through the connecting member, when the motor 141 rotates, the fan 161 is driven to rotate, the fan 161 generates a heat dissipation airflow when rotating, and the heat dissipation airflow flows through the motor 141 and enters the accommodating cavity 153c, the device casing 153 further includes an opening 153d allowing the heat dissipation airflow to flow out of the accommodating cavity 153c, and the opening 153d is used for taking heat out of the opening 153d through the heat dissipation airflow, so as to improve the heat dissipation efficiency. Alternatively, an opening 153d is provided on the case 153a, forming the opening 153d adjacent to the fan 161.

The fan 161 includes a plurality of blades 161a, and the heat dissipation airflow enters the device case 153 after passing through the motor 141, dissipates heat of the speed reduction mechanism 151 in the device case 153, flows out of the device case 153, passes through the fan 161, and finally flows out of the opening 153 d.

Further, the connecting rod 11 is directly communicated with the front end shell 142, so that the connecting rod 11 can be hollow, air enters from the front end of the connecting rod 11 when the grass trimmer runs, enters the front end shell 142 through the connecting rod 11, flows into the device shell 153 from the motor 141 in the front end shell 142, flows out of the device shell 153 and is discharged through the fan, and therefore heat of a switch arranged on the connecting rod 11, the motor 141 and the speed reducing mechanism can be dissipated, and the effect of dissipating heat of the whole grass trimmer is achieved.

Alternatively, the fan 161 includes a fan blade 161a and an anti-wind cover 161b, and the fan blade 161a is mounted to a lower surface of the anti-wind cover 161b, which is a surface of the anti-wind cover 161b close to the grass cutting head 131. The fan 161 is mainly used for dissipating heat from the grass-mowing head 131 and the motor 141, when the fan 161 rotates, a heat dissipation airflow is generated, the heat dissipation airflow is formed in the front-end housing 142 and flows through the motor 141 accordingly, the rear of the transmission device 15 flows to the heat dissipation airflow outside the front-end housing 142, and the device housing 153 forms a guide part for guiding the heat dissipation airflow to flow out from the lower side of the anti-winding cover 161b so as to pass through the heat dissipation airflow.

A heat dissipation airflow which sequentially flows through the motor 141 and the transmission device 15 and then flows to the outside of the front end housing 142 is formed in the front end housing 142; the device case 153 is formed with a guide portion for guiding the heat-dissipating airflow to flow out from the lower side of the anti-wind cover 161b, and a stopper portion for stopping the heat-dissipating airflow from flowing out from the upper side of the anti-wind cover 161b is formed extending from the upper surface of the anti-wind cover 161 b. The stop and guide overlap in a direction perpendicular to the first axis 102.

Fig. 8 is an enlarged view of a part of the structure shown in fig. 5. Referring to fig. 8, in one embodiment, the stopper is a first annular wall 161c formed extending from an upper surface of the anti-wind cover 161b, and the guide is a second annular wall 153e at least partially disposed within the first annular wall 161 c. Specifically, the anti-wind cover 161b prevents grass clippings from being wound around the drive shaft 152 or the fan 161, the anti-wind cover 161b may be considered as a part of the fan 161, the fan blade 161a is disposed on the lower surface of the anti-wind cover 161b, and the anti-wind cover 161b is connected to the fan blade 161a, so that the fan blades 161a can be integrated. Specifically, the anti-wind cover 161b not only has the function of preventing grass from being wound, preventing grass clippings from entering the drive shaft 152 or the fan 161, but also has the function of assisting heat dissipation; a stopper structure for stopping the heat dissipation airflow flowing out from the opening 153d from flowing out from the upper surface of the fan 161 is formed on one side of the motor 141 of the fan 161 in an extending manner. The stopping structure is specifically a first annular wall 161c formed extending from the upper surface of the fan 161, and further, the first annular wall 161c extends upward from the anti-wind cover 161 b. The device housing 153 is formed with a second annular wall 153e which is engaged with the first annular wall 161c, the second annular wall 153e is disposed in the first annular wall 161c, and the first annular wall 161c surrounds the second annular wall 153e, so that the first annular wall 161c and the second annular wall 153e overlap each other to prevent the heat dissipation air flow from flowing out from the upper side of the fan 161, but to make the heat dissipation air flow as much as possible from flowing out from the fan 161 in the radial direction between two adjacent fan blades 161a, which enables the heat dissipation air flow to flow through the outer wall of the device housing 153 as much as possible, thereby improving the heat dissipation effect.

In one embodiment, the anti-wind cover 161b and the fan blade 161a are integrally formed, that is, the anti-wind cover 161b and the fan blade 161a are connected by molding or the like to form the fan 161, and the fan blade 161a extends from an end surface of the anti-wind cover 161b to rotate the fan blade 161a by the anti-wind cover 161b to generate the heat dissipation airflow, and the heat dissipation airflow flows out from the fan 161 to dissipate heat of the front housing 142 and the internal components thereof.

The heat dissipation air flow can enter the device case 153 after passing through the motor 141, and the device case 153 is further formed with an opening 153d for allowing the heat dissipation air flow to flow out of the device case 153. The opening 153d is formed in the case 153a and is disposed close to the fan 161, so that the heat dissipation air flow passes through the motor from the front case 142 and is discharged from the opening 153d through the fan 161 via the device case, thereby effectively improving the efficiency of the deviceThe heat dissipation efficiency is improved. Through the cooperation of fan, guide portion, backstop portion, can effectual improvement radiating effect. Especially the radiating efficiency of motor and drive mechanism in the further promotion front end device, thereby make the utility model provides a volume is less than 45 cm³The motor, and the telescopic diameter of rotor is less than 40 mm's motor heat dispersion is good to and the transmission mechanism heat dispersion of compact setting is good, thereby promote the operating performance of motor and front end device.

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 adopting equivalent replacement or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A long-pole type electric power tool comprising:

a connecting rod having a front end and a rear end in a length direction thereof;

the power supply device is arranged at the rear end of the connecting rod;

the actuating device is used for installing an actuating element and is arranged at the front end of the connecting rod;

the motor is used for driving the executing device to rotate;

the method is characterized in that:

the long-rod-type electric tool further includes:

a transmission device comprising a speed reducing mechanism for realizing power transmission between the motor and the executing device and a device shell for accommodating at least part of the speed reducing mechanism;

the motor includes:

a rotor shaft rotatable about a first axis;

a rotor sleeve mounted to the rotor shaft and configured to rotate in synchronization with the rotor shaft, both ends of the rotor shaft passing through the rotor sleeve;

a stator core at least partially disposed within the rotor sleeve;

a stator coil wound around the stator core;

the rotor shaft extends into a space surrounded by the device shell and is connected with the speed reducing mechanism.

2. The long-pole type electric tool according to claim 1, characterized in that:

the diameter D1 of the rotor sleeve is set to be 40mm or less, and the ratio of the output power P of the motor to the diameter D1 of the rotor sleeve is 80W/cm or more and 160W/cm or less.

3. The long-pole type electric tool according to claim 2, characterized in that: the motor is a brushless motor, and the diameter D1 of the rotor sleeve is less than or equal to 35 mm.

4. The long-pole type electric tool according to claim 2, characterized in that:

the diameter D1 of the rotor sleeve is 35 mm; the ratio of the output power P of the motor to the volume V of the motor is more than or equal to 11W/cm³And is less than or equal to 35W/cm³。

5. The long-pole type electric tool according to claim 2, characterized in that:

the ratio of the rotating speed of the rotor shaft to the rotating speed of the executing device is defined as a reduction ratio R of the speed reducing mechanism, and the reduction ratio R of the speed reducing mechanism is greater than or equal to 3.5 and less than or equal to 7.

6. The long-pole type electric tool according to claim 5, wherein:

the rotating speed of the rotor shaft is more than or equal to 24000 rpm.

7. The long-pole type electric tool according to claim 6, wherein:

the rotating speed of the executing device is more than or equal to 4000rpm and less than or equal to 6500 rpm.

8. The long-pole type electric tool according to claim 2, characterized in that:

the long-rod-type electric tool further includes:

a front end housing including a first receiving portion for receiving at least a portion of the motor and a second receiving portion for receiving at least a portion of the transmission;

9. The long-pole type electric tool according to claim 2, characterized in that:

the speed reducing mechanism further includes:

the driving shaft is connected with the executing device to drive the executing device to rotate;

the driving shaft can rotate by taking a second axis as an axis; the first axis and the second axis are parallel to each other, and the distance between the first axis and the second axis is greater than or equal to 10mm and less than or equal to 25 mm.

10. The long-pole type electric tool according to claim 9, characterized in that:

the speed reducing mechanism further includes:

a gear mounted to the driving shaft to receive power output from the motor;

two bearings installed to the driving shaft and respectively provided at both sides of the gear.

11. The long-pole type electric power tool according to any one of claims 2 to 10, wherein:

the executing device is a grass cutting head for cutting grass.