Chain saw

Abstract

The utility model discloses a chain saw. The chainsaw includes: a housing; the chain is arranged around the periphery of the guide plate, one end of the guide plate is supported on the shell, and the other end of the guide plate extends out of the shell in the lengthwise direction of the shell; the motor is used for driving the chain to cut; the position detection assembly is used for detecting the rotor position of the motor; the position detection assembly comprises a magnetic part and a position sensor; the magnetic part is arranged at one end of an output shaft of the motor, the shell is provided with an air guide part used for guiding heat dissipation airflow, and the position sensor is arranged on the air guide part. According to the chain saw, the specific positions of related assemblies used for detecting the position of the motor rotor can be reasonably deployed, under the condition that the inductive motor is adopted, the accuracy of motor operation control is guaranteed, and the requirements for the compact structure and the high output performance of the chain saw can be effectively met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric power tools, for example to a chain saw. BACKGROUND

[0002] Chain saw is a common handheld garden tool, which is widely used with the increasing private and public green areas. At present, chain saws mostly use electric energy as power source. The motor in the chain saw can drive the chain to rotate around the guide plate, and then the staggered L-shaped blades on the chain cut the wood or branches. In order to meet the increasing use requirements of users, it is necessary to reasonably arrange the components in the chain saw, so as to improve the output performance of the chain saw while considering the compactness of the structure.

[0003] This part provides background information related to the present application, which may not be prior art. SUMMARY

[0004] It is an object of the present application to solve or at least reduce some or all of the above problems. To this end, the present application provides a chain saw. In order to achieve the above object, the present application adopts the following technical solution:

[0005] A chain saw, comprising: a housing; a chain and a guide plate, the chain being arranged around the outer periphery of the guide plate, one end of the guide plate being supported on the housing, and the other end extending out of the housing along the longitudinal direction of the housing; a motor for driving the chain to cut; a position detection assembly for detecting the position of the rotor of the motor; the position detection assembly comprises a magnetic member and a position sensor; the magnetic member is arranged on one end of the output shaft of the motor, the housing has a wind guide portion for guiding the heat dissipation airflow, and the position sensor is arranged on the wind guide portion.

[0006] In some embodiments, the output shaft end is provided with a mounting member on which the magnetic member can be mounted, and the magnetic member is connected to the output shaft end through the mounting member.

[0007] In some embodiments, the mounting member is sleeved on the end of the output shaft away from the chain and the guide plate and has a mounting groove in which the magnetic member can be embedded.

[0008] In some embodiments, the chain saw further comprises a fan arranged on the output shaft and located between the magnetic member and the motor in the axial direction of the output shaft, and the magnetic member is located between the position sensor and the fan.

[0009] In some embodiments, the projection of the magnetic member and the position sensor in the axial direction of the output shaft at least partially overlaps.

[0010] In some embodiments, the straight line on which the output shaft is located is substantially perpendicular to the plane on which the guide plate is located.

[0011] In some embodiments, the housing comprises a wind guide cover, and the wind guide portion is located on the wind guide cover.

[0012] In some embodiments, the shroud is formed with a recess away from the motor, and the position sensor is disposed in the recess.

[0013] In some embodiments, the recess has an opening for the passage of the circuit cable and cooling airflow.

[0014] In some embodiments, the end of the output shaft to which the magnetic member is mounted at least partially extends into the recess.

[0015] In some embodiments, the chain saw further comprises a circuit board assembly and an oil tank, and a projection of the motor in a plane perpendicular to the guide plate substantially falls within a projection of the circuit board assembly in the plane perpendicular to the guide plate.

[0016] In some embodiments, the chain saw has an output power greater than or equal to 1000W.

[0017] In some embodiments, the chain saw has a chain speed greater than or equal to 10m / s.

[0018] In some embodiments, the motor has a power density greater than 1000W / kg.

[0019] In some embodiments, the motor has an outer diameter greater than or equal to 50mm.

[0020] In some embodiments, the motor comprises a stator and a rotor rotating relative to the stator, and the stator is provided at a radial center thereof with a support comprising a rim portion and a spoke portion.

[0021] An electric power tool, comprising: a motor for providing power to the electric power tool, the motor comprising a stator and a rotor rotating relative to the stator; a power supply device electrically connected to at least the motor; an output portion driven by the motor; and a support comprising a rim portion and a spoke portion provided at a radial center of the stator.

[0022] In some embodiments, the electric power tool further comprises a housing formed with an accommodation space, and the output portion comprises a functional member; the motor is disposed in the accommodation space of the housing and drives the functional member to perform a corresponding function.

[0023] In some embodiments, the rotor is sleeved outside the stator, and the support is disposed inside the stator and supports the stator.

[0024] In some embodiments, the support is made of metal or modified plastic.

[0025] In some embodiments, an outer diameter ratio of the stator to the rotor is greater than or equal to 0.7.

[0026] In some embodiments, a pole arc coefficient of the rotor is greater than or equal to 0.6 and less than 1.

[0027] In some embodiments, the motor has a power density greater than or equal to 2000W / kg.

[0028] In some embodiments, the stator comprises a stator core and a stator winding, the stator core has a plurality of radially extending teeth, the stator winding is wound on the teeth; the teeth are not equally wide in the radial direction, wherein the width of the teeth is the width of the teeth in the direction perpendicular to the extension direction thereof.

[0029] In some embodiments, the ratio of the maximum value to the minimum value of the width of the teeth is greater than 1 and less than or equal to 1.8.

[0030] In some embodiments, the rotor comprises a rotor core and a magnetic steel, the magnetic steel is fixed to the rotor core in a plastic-bonded manner.

[0031] In some embodiments, the motor further comprises a bracket, the stator and the rotor are sleeved on the bracket, the support is coaxially arranged with the bracket, and the bracket is formed with an air inlet and an air outlet through which the cooling airflow passes.

[0032] In some embodiments, the power tool further comprises a fan, and the motor further has a motor housing, the motor housing is integrally formed with the fan.

[0033] In some embodiments, the rotor comprises a rotor core, and an inner wall of the motor housing is formed with a limiting boss for limiting the rotor core in the axial direction.

[0034] The technical effects of the present application at least include: the specific positions of the related components for detecting the position of the rotor of the chain saw motor are reasonably deployed, the specific positions of the magnetic member and the position sensor can meet the performance requirements of the related driving control in the high-power and high-chain-speed chain saw, and the space in the chain saw shell can be reasonably and effectively utilized, and compactness and hand feeling are considered. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a plan view of the chain saw in the present application as an embodiment;

[0036] Figure 2 is a plan view of the chain saw in the present application as an embodiment; Figure 1

[0037] Figure 3 is a plan view of the chain saw in the present application as an embodiment; Figure 1

[0038] Figure 4 is a plan view of the chain saw in the present application as an embodiment; Figure 2

[0039] Figure 5 is a plan view of the chain saw in the present application as an embodiment; Figure 1

[0040] Figure 6 ​​​​is Figure 5 isometric view of the motor and magnetic element in the chain saw shown in Fig. 1;

[0041] Figure 7 is Figure 5 plan view of the shroud, position sensor in the chain saw shown in Fig. 1;

[0042] Figure 8 is Figure 5 exploded view of the motor, mounting element, magnetic element, position sensor, shroud in the chain saw shown in Fig. 1;

[0043] Figure 9 isometric view of the electric power tool as an embodiment in the present application;

[0044] Figure 10 is Figure 9 exploded view of the motor in the electric power tool shown in Fig. 2;

[0045] Figure 11 is Figure 10 plan view of the stator, rotor, motor housing in the motor of the electric power tool shown in Fig. 2;

[0046] Figure 12 is Figure 10 cross-sectional view of the rotor core, rotor magnet, plastic element in the motor of the electric power tool shown in Fig. 2;

[0047] Figure 13 is Figure 10 cross-sectional view of the motor housing, fan, limit boss in the motor of the electric power tool shown in Fig. 2;

[0048] Figure 14 is Figure 10 plan view of the stator core and stator winding in the motor of the electric power tool shown in Fig. 2;

[0049] Figure 15 is Figure 10 plan view of the rotor, stator, support element, output shaft in the motor of the electric power tool shown in Fig. 2;

[0050] Figure 16 is Figure 10 isometric view of the support element and bracket in an embodiment in the motor of the electric power tool shown in Fig. 2;

[0051] Figure 17 is Figure 16 cross-sectional view of the base, tube element, support element, stator core in the motor of the electric power tool shown in Fig. 2;

[0052] Figure 18 is Figure 10 isometric view of the bracket in another embodiment in the motor of the electric power tool shown in Fig. 2;

[0053] Figure 19 is Figure 18A cross-sectional view of the base, tube member, and output shaft of the electric power tool motor.

[0054] Figure caption: 100, chain saw; 100a, snow blower; 10, housing; 110, air guide / air guide cover; 111, groove; 112, opening; 20, output / functional part; 21, chain, 22, guide plate; 30, power supply device; 40, circuit board assembly; 51, oil pot; 200, motor; 210, stator; 220, rotor; 221, rotor core; 222, magnetic steel; 226, output shaft; 227, plastic part; 230, motor housing; 231, fan; 232, limiting boss; 240, position detection assembly; 241, magnetic part; 242, position sensor; 243, mounting part; 2431, mounting groove; 250, support part; 251, rim part; 252, spoke part; 260, bracket; 261, base; 2611, air inlet; 262, tube member; 2621, air outlet. DETAILED DESCRIPTION

[0055] Before any embodiments of the application are explained in detail, it is to be understood that the application is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the above-described accompanying drawings.

[0056] In this application, the terms "including", "containing", "having" or any other similar words are intended to encompass non-exclusive inclusion, so that a process, method, article or apparatus including a series of elements includes not only those elements, but also other elements not explicitly listed, or other elements inherent in such a process, method, article or apparatus. Without more limitations, the element defined by the phrase "including a" does not exclude the presence of other identical elements in the process, method, article or apparatus including the element.

[0057] In this application, the term "and / or", is a description of the association relationship between the associated objects, which means that there can be three kinds of relationships. For example, A and / or B, can represent: A exists alone, A and B exist together, B exists alone, these three cases. In addition, the character " / " in this application generally represents that the front and rear associated objects are a "and / or" relationship.

[0058] In this application, the terms "connect," "couple," "coupled," "mount," and "mounting" can be direct or indirect, and can include mechanical, electrical, and / or logical connections, among others.

[0059] In this application, those of ordinary skill in the art will appreciate that the use of relative terms (e.g., "about," "approximately," "substantially," etc.) in connection with a quantity or condition will be understood to include the stated value and possess the meaning indicated by the context. For example, the relative terms will at least include an amount of error associated with a measurement of a particular value, a tolerance in a particular value resulting from manufacturing, assembly, use, etc. Such terms should also be considered as disclosing a range that is defined by the absolute values of the two endpoints. The relative terms can refer to a percentage (e.g., 1%, 5%, 10% or more) of the indicated value plus or minus. Values that do not employ a relative term should also be disclosed as particular values with tolerances. In addition, "substantially" when used in the context of a relative angular positional relationship (e.g., substantially parallel, substantially perpendicular) can refer to plus or minus a certain number of degrees (e.g., 1 degree, 5 degrees, 10 degrees or more) from the indicated angle.

[0060] In this application, those of ordinary skill in the art will appreciate that a function performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, a function performed by a part can be performed by one part, one component, or a combination of multiple parts.

[0061] In this application, the terms "upper," "lower," "left," "right," "front," "back," and the like describe the orientation and position as shown in the drawings, and should not be construed to limit the embodiments of the present application. In addition, it will be understood that, when an element is referred to as being "on" or "under" another element, it can be directly on or under the other element, or indirectly connected by intervening elements. It will also be understood that the terms "upper," "lower," "left," "right," "front," "back," and the like can refer to a side view, and can also be understood as a side view. For example, "lower" can include directly below, left below, right below, front below, and back below, among others.

[0062] In the present application, the terms "controller", "processor", "central processing unit", "CPU", "MCU" are interchangeable. In using the unit "controller", "processor", "central processing unit", "CPU", or "MCU" to perform a specific function, unless otherwise specified, these functions can be performed by a single above-mentioned unit or multiple above-mentioned units.

[0063] In the present application, the terms "device", "module" or "unit" in order to achieve a specific function, it can be realized by hardware or software form.

[0064] In the present application, the terms "calculate", "judge", "control", "determine", "identify" and the like refer to the operation and process of a computer system or similar electronic computing device (e.g., controller, processor, etc.).

[0065] The technical solutions proposed in the present application are described in detail below in conjunction with specific embodiments and drawings.

[0066] Reference Figures 1 to 8 It shows a chain saw 100 as an embodiment in the present application. At the same time, the figure also defines the front, back, left, right, up and down directions in the present application. The chain saw 100 can include a tool body and a power supply device 30 for providing energy for the tool body. In some embodiments, the power supply device 30 can be a battery pack that is detachably connected with the tool body of the chain saw 100.

[0067] The tool body of the chain saw 100 includes a housing 10, a chain 21 and a guide plate 22. Among them, the housing 10 constitutes the main body of the chain saw 100, and the inside forms an accommodating space, and the housing 10 can support and accommodate the components to be described later. The chain 21 is the functional part 20 that actually implements the cutting when the chain saw 100 works. The guide plate 22 supports and guides the chain 21, one end of which is supported on the housing 10, and the other end extends out of the housing 10 along the longitudinal direction of the housing 10, i.e. the front and back direction.

[0068] In addition to the housing 10, the chain 21 and the guide plate 22, the chain saw 100 further comprises a motor 200 and a position detection assembly 240. The motor 200 is a prime mover of the chain saw 100, which can be arranged in a receiving space formed by the housing 10, and converts the electric energy provided by the power supply device 30 into mechanical energy of the output shaft 226 of the motor 200, which in turn directly or indirectly drives the chain 21 to cut around the guide plate 22. The motor 200 comprises a stator 210 and a rotor 220 rotating relative to the stator 210. In the present application, the motor 200 used in the chain saw 100 is a dynamo, and the position detection assembly 240 is also used in the chain saw 100 to detect the position of the rotor 220 of the motor 200. Specifically, the chain saw 100 further comprises a controller and a driving circuit. The controller can control the operation of the motor 200, which receives the data related to the position of the rotor of the motor 200 detected by the position detection assembly 240, calls the relevant control program and outputs the control signal to the driving circuit based on the above-mentioned data, so that the driving circuit adjusts the driving signal and in turn changes the magnetic field of the stator 210, drives the rotor 220 and the output shaft 226 of the motor 200 to operate in the expected manner.

[0069] In the present application, as shown in Figures 4 to 8 The position detection assembly 240 of the chain saw 100 comprises a magnetic member 241 and a position sensor 242, which can perceive the position of the rotor 220 by using the electromagnetic induction phenomenon between the magnetic member 241 and the position sensor 242. The magnetic member 241 is arranged on one end of the output shaft 226 of the motor 200, and the position sensor 242 is arranged on the air guide part 110 of the housing 10 for guiding the flow of cooling air. Specifically, the magnetic member 241 can be a magnet, and the position sensor 242 can be a magnetic encoder, a Hall sensor, etc. The above-mentioned magnetic encoder, Hall sensor, etc. are built-in with a Hall element, and the position sensor 242 can perceive the size and direction of the magnetic field of the rotor 220 by using the Hall effect between the Hall element and the magnet, so as to deduce the current position of the rotor 220 of the motor 200. The air guide part 110 of the housing 10 in the chain saw 100 is generally adjacent to the motor 200, and the magnetic member 241 and the position sensor 242 are arranged at the above-mentioned position, which can effectively use the original installation space in the chain saw 100, and can also meet the relative position relationship required by the magnetic member 241 and the position sensor 242 when they cooperate and work normally. In addition, the position sensor 242 located on the air guide part 110 can also achieve effective heat dissipation, which can meet the design requirements of compact structure, high power and high chain speed of the chain saw 100.

[0070] In some embodiments, the magnetic member 241 is fixed to the non-output end of the output shaft 226 of the motor 200, i.e. the end away from the guide plate 22 and the chain 21, and is provided with a mounting member 243 for mounting the magnetic member 241, and the magnetic member 241 is connected to the output shaft 226 of the motor 200 through the mounting member 243. In some embodiments, as shown in Figure 8 the mounting member 243 is sleeved on the non-output end of the output shaft 226 of the motor 200, and has a mounting groove 2431 for embedding the magnetic member 241, and the radial cross section of the mounting member 243 can be in the shape of "H". In some embodiments, the magnetic member 241 can be in the shape of a disc.

[0071] In some embodiments, the chain saw 100 further comprises a fan 231 mounted on the output shaft 226 of the motor 200, and the fan 231 is located between the magnetic member 241 and the motor 200 along the axial direction of the output shaft 226, and the magnetic member 241 is located between the air guide part 110 and / or the position sensor 242 and the fan 231. In other words, as shown in Figures 5 to 8 from the non-output end to the output end of the output shaft 226 of the motor 200, the air guide part 110 of the housing 10, the position sensor 242, the magnetic member 241, the fan 231, and the stator 210 and the rotor 220 of the motor 200 are arranged in sequence.

[0072] In some embodiments, as shown in Figures 4 to 8 the housing 10 of the chain saw 100 comprises an air guide cover 110, and the air guide part 110 is located in the air guide cover 110. In some embodiments, the housing 10 of the chain saw 100 comprises an outer housing and an inner housing, and the air guide cover 110 belongs to the inner housing, which can support and accommodate the motor 200 and can cooperate with the air outlet on the outer housing to guide the heat dissipation airflow flowing through the motor 200 out of the housing 10. In other embodiments, the air guide cover 110 can also belong to the outer housing, which has an air outlet for the heat dissipation airflow to blow out.

[0073] In some embodiments, as shown in Figure 5 , Figure 7 the air guide cover 110 has a recess 111 away from the motor 200, and the position sensor 242 is arranged in the recess 111. Specifically, the bottom of the recess 111 can serve as a mounting surface for the position sensor 242 to be connected by screws or the like. In some embodiments, the recess 111 is further provided with an opening 112 for the circuit cable and the heat dissipation airflow to pass through, so that the data of the position sensor 242 can be output and better heat dissipation can be achieved.

[0074] In some embodiments, the magnetic member 241 is mounted on the output shaft 226 of the motor 200, and one end of the magnetic member 241 extends into the recess 111, so that the position sensor 242 can accurately and effectively detect the position of the rotor of the motor 200 by sensing the magnetic member 241.

[0075] In some embodiments, as shown in Figure 4 、 Figure 8 The magnetic member 241 and the position sensor 242 are at least partially overlapped in the axial direction of the output shaft 226 of the motor 200. In some embodiments, the position sensor 242 can be a magnetic encoder, and the number of the position sensor 242 can be one, which is located near the position facing the radial center of the motor 200. In other embodiments, the position sensor 242 can be a linear Hall sensor, and the number of the position sensor 242 can be two or three, which are arranged in the circumferential direction of the output shaft 226 of the motor 200.

[0076] In some embodiments, the motor 200 and the output shaft 226 thereof extend in the transverse direction of the housing 10, i.e., the left-right direction, and the straight line on which the output shaft 226 is located is substantially perpendicular to the plane on which the guide plate 22 is located. In the light of the foregoing, in some embodiments, the plane on which the magnetic member 241 in the shape of a disc or the like is located is substantially parallel to the plane on which the guide plate 22 is located. In some embodiments, the groove body of the recess 111 extends in the left-right direction. In some embodiments, the mounting surface of the groove bottom or the plane on which the position sensor 242 is located or the plane on which the plurality of position sensors 242 are located together can be substantially parallel to the plane on which the guide plate 22 is located.

[0077] In some embodiments, as shown in Figure 2 、 Figure 3 The chain saw 100 further comprises a circuit board assembly 40 and an oil tank 51, and the orthographic projection of the motor 200 and the oil tank 51 in the plane perpendicular to the guide plate 22 falls into the orthographic projection of the circuit board assembly 40 in the plane perpendicular to the guide plate 22, i.e., the projection of the motor 200 and the oil tank 51 in the up-down direction falls into the projection of the circuit board assembly 40 in the up-down direction, so that the space in the housing of the chain saw 100 is fully utilized, and the combined space of the three is reduced. In some embodiments, the circuit board assembly 40 is located above the motor 200 and the oil tank 51. In some embodiments, the motor 200 and the oil tank 51 are arranged in the front-rear direction.

[0078] In addition, as mentioned above, the chain saw 100 has a compact and high power feature. In some embodiments, the chain saw 100 has an output power greater than or equal to 1000 W. Preferably, in some embodiments, the chain saw 100 has an output power greater than or equal to 3000 W. Preferably, in some embodiments, the chain saw 100 has an output power greater than or equal to 5000 W. The output power of the power tool can be calculated based on the average working current of the power tool and the power supply device 30 such as the battery pack. The average working current of the power tool generally varies within a numerical range, and the output power thereof can correspondingly vary within a numerical range. In some embodiments, the maximum output power of the chain saw 100 is greater than or equal to 5000 W.

[0079] In some embodiments, the chain speed of the chain saw 100 is greater than or equal to 10 m / s. Preferably, in some embodiments, the chain speed of the chain saw 100 is greater than or equal to 20 m / s. Preferably, in some embodiments, the chain speed of the chain saw 100 is greater than or equal to 40 m / s. The chain speed of the chain saw 100 can be the speed of the tooth portion of the chain 21 passing through the cutting object when the chain saw 100 is working.

[0080] In some embodiments, the power density of the motor 200 of the chain saw 100 is greater than or equal to 1000 W / kg. Preferably, in some embodiments, the power density of the motor 200 of the chain saw 100 is greater than or equal to 2000 W / kg. Preferably, in some embodiments, the power density of the motor 200 of the chain saw 100 is greater than or equal to 3000 W / kg. The power density of the motor 200 can be the ratio between its rated power and the mass of its necessary components.

[0081] In some embodiments, the outer diameter of the motor 200 of the chain saw 100 is greater than or equal to 50 mm. Preferably, in some embodiments, the outer diameter of the motor 200 of the chain saw 100 is greater than or equal to 70 mm.

[0082] As mentioned above, the motor 200 used in the chain saw 100 of the present application can also be applied to other types of power tools to make the power tools have better output and heat dissipation performance. Referring to Figure 1 、 Figure 9 , which shows the power tools as several embodiments of the present application. It can be understood that, Figure 1 the chain saw 100 shown and Figure 9 the snow blower 100a shown do not constitute specific limitations on the technical solutions of the power tools and the motors thereof to be described below. The power tools described below include not only handheld tools such as chain saws, circular saws, and electric drills, but also bench tools such as miter saws and table saws, and outdoor power equipment such as snow blowers and lawn mowers.

[0083] As Figure 1 、 Figure 9As shown, the power tool includes a housing 10, an output 20, a motor 200, and a power supply 30. As mentioned above, the housing 10 forms an accommodating space, and the motor 200 is accommodated in the accommodating space of the housing 10. The housing 10 also generally forms a joint portion for mounting the power supply 30, such as a battery pack, to the power tool and supplying power to the power tool. The output 20 is driven by the motor 200 to perform corresponding tool functions, such as cutting, grinding, fastening, etc. The output 20 includes a functional piece 20 that actually performs the above-mentioned functions. For example, the functional piece 20 can be a saw blade, a chain, a drill bit, etc., which can be directly or indirectly driven by an output shaft 226 of the motor 200 through a transmission assembly.

[0084] With reference to Figures 10 to 19 The motor 200, i.e., the electric machine, includes a stator 210 and a rotor 220 that rotates around the stator 210, and the stator 210 and the rotor 220 are arranged in a nested manner. In the case of an external rotor motor, the stator 210 is on the inside in the radial direction, and the rotor 220 is at least partially arranged on the outside of the stator 210 and rotates relative to the stator 210. In the case of an internal rotor motor, the stator 210 is on the outside in the radial direction, and the rotor 220 is at least partially arranged on the inside of the stator 210 and rotates relative to the stator 210. In some embodiments, the motor is a brushless motor. In some embodiments, the motor is a permanent magnet synchronous motor. Hereinafter, an external rotor permanent magnet synchronous motor is mainly described. The rotor 220 includes a rotor core 221 and a magnet 222 fixed to the rotor core 221, and the stator 210 includes a stator core 211 and a stator winding 212 wound on the stator core 211. The rotor core 221 and the magnet 222 of the rotor 220 are arranged outside the stator core 211 and the stator winding 212 of the stator 210.

[0085] In the motor 200 of the power tool in the present application, a support 250 in the form of a rim and spoke structure will be added, as shown in Figure 15As shown, the stator 210 is provided with the support 250 at its radial center, which includes a rim portion 251 and a spoke portion 252. The rim portion 251 constitutes the outer edge of the support 250, and the spoke portion 252 is connected to the rim portion 251 within the rim portion 251 and forms a through hole for the output shaft 226 to pass through. In some embodiments, the support 250 supports the stator 210 at its outer periphery, and the rim portion 251 supports the stator core 211. The spoke portion 252 includes a plurality of spokes extending radially inward from the rim portion 251, and the plurality of spokes do not intersect and form a through hole for the output shaft 226 to pass through at the radial center of the stator 210. In some embodiments, the rim portion 251 includes an inner rim and an outer rim. The outer rim supports the stator core 211, and the inner rim forms a through hole for the output shaft 226 to pass through. The plurality of spokes of the spoke portion 252 are connected between the inner rim and the outer rim. The support 250 has a rim and spoke structure, which leaves a large hollow space in the rotor 220 and the stator 210 of the motor 200. Compared with the common bearing support scheme, the support 250 has obvious improvement in heat dissipation performance, and can also reduce weight and cost.

[0086] In some embodiments, the support is made of metal or modified plastic. The metal or modified plastic used has the characteristics of light weight and good heat dissipation, so as to better achieve the improvement effect described above and be easy to process. In some embodiments, the support is made of aluminum. In other embodiments, the support is made of thermoplastic or thermosetting plastic.

[0087] In some embodiments, the motor 200 is an inductive motor, which detects the position of the rotor 220 using a position sensor, such as a magnetic encoder. The position sensor can be installed near the end of the output shaft 226 of the motor 200, for example, as shown above. Alternatively, the position sensor, such as a Hall sensor, can be installed near the teeth or slots of the stator core 211 of the stator 210 of the motor 200.

[0088] In some embodiments, the power density of the motor 200 is greater than or equal to 2000 W / kg. Preferably, in some embodiments, the power density of the motor 200 is greater than or equal to 3000 W / kg. The power density of the motor 200 can be the ratio of its rated power to the mass of its necessary components. In some embodiments, the rated power of the motor 200 is greater than or equal to 3000 W and less than or equal to 7000 W. In other embodiments, the no-load rotating speed of the motor 200 is greater than or equal to 10000 rpm and less than or equal to 17000 rpm. In yet other embodiments, the outer diameter of the motor 200 is greater than or equal to 50 mm. Preferably, in some embodiments, the outer diameter of the motor 200 is greater than or equal to 50 mm and less than or equal to 105 mm. Preferably, in some embodiments, the outer diameter of the motor 200 is greater than or equal to 80 mm and less than or equal to 95 mm.

[0089] In some embodiments, the motor 200 is an external rotor motor, and the ratio of the outer diameter D1 of the stator 210 to the outer diameter D2 of the rotor 220 is greater than or equal to 0.7 and less than 1. In some embodiments, the ratio of the outer diameter D1 of the stator 210 to the outer diameter D2 of the rotor 220 is greater than or equal to 0.8 and less than 1. Figure 11 Figure 12 In some embodiments, the outer diameter D1 of the stator 210 of the motor 200 can be the outer diameter of the stator core 211 of the motor 200, and the outer diameter D2 of the rotor 220 can be the outer diameter of the rotor core 221. Preferably, in some embodiments, the ratio of the outer diameter D1 of the stator 210 to the outer diameter D2 of the rotor 220 is greater than or equal to 0.8 and less than 1, so that the stator 210 and the rotor 220 are more compactly configured to form the motor 200, and the size of the motor 200 is reduced.

[0090] In some embodiments, the pole arc coefficient of the rotor 220 of the motor 200 is greater than or equal to 0.6 and less than 1. In some embodiments, the pole arc coefficient of the rotor 220 of the motor 200 is greater than or equal to 0.7 and less than 1. Figure 12 In some embodiments, the pole arc coefficient of the rotor 220 of the motor 200 is greater than or equal to 0.6 and less than 1. In some embodiments, the pole arc coefficient of the rotor 220 of the motor 200 is greater than or equal to 0.7 and less than 1.

[0091] In some embodiments, the magnetic steel 222 in the rotor 220 is fixed to the rotor core 221 in a plastic-wrapped manner. As shown in Figure 10 Figure 12 Figure 15 In some embodiments, the motor housing 230 is an aluminum part, which is hot-fitted with the rotor core 221. In some embodiments, the inner wall of the motor housing 230 is further formed with a limiting boss 232 for limiting the rotor core 221 in the axial direction, thereby enhancing the fixing effect of the motor housing 230 on the rotor core 221.

[0092] In some embodiments, the motor 200 further comprises a motor housing 230 and a fan 231 integrally formed with the motor housing 230, and the fan 231 is arranged on the output shaft 226 of the motor 200 and located on a plane perpendicular to the output shaft 226 of the motor 200. As shown in Figure 10 Figures 16 to 19 ​​​​As shown, the fan 231 is integrally formed with the motor housing 230, and is arranged on the output shaft 226 of the motor 200, which can be in interference fit with the motor housing 230 to ensure stable connection. From the non-output end to the output end of the motor 200, the motor housing 230 is sequentially provided with the fan 231, a limiting boss 232, a housing main body, and another limiting boss 232, and the rotor core 221 is supported and limited by the limiting boss 232 in the housing main body.

[0093] In some embodiments, the motor 200 further comprises a bracket 260, and the stator 210, the rotor 220, the output shaft 226, the support 250, and the bracket 260 are coaxially arranged, and the stator 210, the rotor 220, the output shaft 226, and the support 250 can be sleeved or penetrated on the bracket 260. In the present embodiment, the bracket 260 further forms or cooperates with the above components to form an air inlet 2611 and an air outlet 2621 through which cooling air flows. Specifically, as shown in Figure 16 The bracket 260 can include a base 261 and a pipe component 262, and the base 261 is connected or integrally formed with the pipe component 262. The plane on which the base 261 is located can be substantially perpendicular to the straight line on which the pipe component 262 is located. The base 261 is axially away from the fan 231, and the pipe component 262 can be sleeved or penetrated by the stator 210, the rotor 220, the output shaft 226, and the support 250. The bracket base 261 is provided with a radially or axially extending air inlet 2611, and the pipe component 262 can form an axially extending air outlet 2621 with the output shaft 226 or the support 250 penetrated therein. The cooling air will be blown into the air inlet 2611, taking away the heat on the surface of the stator 210 and / or the support 250 attached to the bracket 260, and then blown out of the air outlet 2621.

[0094] In some embodiments, the support 250 is connected or integrally formed with the bracket 260, as shown in Figure 17 , Figure 18 The support 250 in the form of a rim and spoke structure is arranged in the pipe component 262 of the bracket 260, the output shaft 226 is penetrated in the support 250, the stator 210 and the rotor 220 are sleeved outside the pipe component 262, and the bracket 260 cooperates with the support 250 to form an axially extending air flow channel to effectively cool the stator 210 attached to the outer periphery of the bracket 260 and the support 250 in the air flow channel. In other embodiments, as shown in Figure 19 , Figure 14As shown, the air inlet 2611 extends radially in the base 261, the tube component 262 cooperates with the output shaft 226 inside which the tube component 262 is arranged to form an air flow channel, and the air outlet 2621 extends axially between the tube component 262 and the output shaft 226. The stator 210, the rotor 220, and the support 250 can be arranged outside the tube component 262 of the bracket 260. In some other embodiments, the projection of the support 250 and the bracket 260 in the axial direction of the motor 200 can partially overlap, and / or the projection of the support 250 and the bracket 260 in the radial direction of the motor 200 can partially overlap or not overlap.

[0095] In some embodiments, the stator core 211 is provided with a plurality of radially extending teeth in the circumferential direction, and the stator winding 212 is wound on the teeth. In addition, the teeth of the stator core 211 have the feature of being of unequal width in the radial direction. For example, Figure 14 As shown, the width W of the tooth of the stator core 211 is the width of the tooth in the direction perpendicular to the extending direction of the tooth. In some embodiments, the teeth of unequal width in the radial direction have a ratio of the maximum value of the width to the minimum value of the width greater than 1 and less than or equal to 1.8. For example, ​ As shown, the maximum value of the width of the tooth of the stator core 211 of the motor 200 is located at the tooth top, i.e., W1, and the minimum value of the width of the tooth is located at the tooth bottom, i.e., W2, and the ratio of the two is in the range of 1 to 1.8. In addition, the tooth top is the end of the tooth away from the yoke of the core, and the tooth bottom is the end of the tooth close to the yoke of the core. Preferably, in some embodiments, the ratio of the maximum value of the width of the tooth to the minimum value of the width is greater than 1 and less than or equal to 1.5.

[0096] In some embodiments, the stator windings 212 wound on different teeth of the stator core 211 are in-phase or out-of-phase relationship. For example, in a three-phase motor, a plurality of windings wound on a plurality of teeth can belong to the A phase of the motor, and a plurality of windings wound on another plurality of teeth can belong to the B phase of the motor. The specific winding sequence and connection relationship can be variable. In the present embodiment, the number of turns of two stator windings 212 belonging to the same phase can be different. The number of turns of the stator winding 212 is the number of wires wound on the tooth. In some embodiments, the motor 200 is a 10-pole 12-slot motor, the number of rotor magnetic steels 222 is 10, and the stator core 211 has 12 teeth. It can be understood that in other embodiments, the number of rotor magnetic steels 222 and the number of stator 210 teeth can also be adjusted according to actual scenarios.

[0097] The numerical settings of the above-mentioned parameters such as the outer diameter ratio of the stator and rotor 210, 220, the pole arc coefficient of the rotor 220, the tooth width of the stator core 211, and the number of turns of the stator winding 212 are aimed at ensuring that the high-power motor 200 operates accurately and efficiently. According to simulation and experiments, the relevant parameters can achieve the effects of improving the slot fill rate, reducing the harmonic distortion rate, stabilizing the torque fluctuation, and reducing the motor noise.

[0098] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the above embodiments do not limit the present application in any form, and any technical solutions obtained by equivalent replacement or equivalent transformation fall within the protection scope of the present application.

Claims

1. A chainsaw, comprising: case; A chain and a guide plate, wherein the chain is arranged around the outer periphery of the guide plate, one end of the guide plate is supported on the housing, and the other end extends out of the housing along the longitudinal direction of the housing; A motor is used to drive the chain to perform the cutting. A position detection component for detecting the rotor position of the motor; The position detection component is characterized in that it includes a magnetic component and a position sensor; the magnetic component is disposed on one end of the output shaft of the motor, the housing has a guide section for guiding heat dissipation airflow, and the position sensor is disposed on the guide section.

2. The chainsaw according to claim 1, characterized in that, The output shaft end is provided with a mounting component for mounting the magnetic component, and the magnetic component is connected to the output shaft end through the mounting component.

3. The chainsaw according to claim 2, characterized in that, The mounting component is sleeved on the end of the output shaft away from the chain and the guide plate and has a mounting groove for the magnetic component to be embedded.

4. The chainsaw according to claim 1, characterized in that, The chainsaw also includes a fan mounted on the output shaft. Along the axial direction of the output shaft, the fan is located between the magnetic component and the motor, and the magnetic component is located between the position sensor and the fan.

5. The chainsaw according to claim 1, characterized in that, The magnetic component and the projection of the position sensor onto the output shaft axis at least partially overlap.

6. The chainsaw according to claim 1, characterized in that, The housing includes an air guide shroud, and the air guide portion is located on the air guide shroud.

7. The chainsaw according to claim 6, characterized in that, The air guide shroud has a groove away from the motor, and the position sensor is disposed in the groove.

8. The chainsaw according to claim 7, characterized in that, The end of the output shaft on which the magnetic component is mounted extends at least partially into the groove.

9. The chainsaw according to claim 1, characterized in that, The chainsaw also includes a circuit board assembly and an oil reservoir. The orthographic projections of the motor and the oil reservoir in a plane perpendicular to the guide plate substantially fall within the orthographic projection of the circuit board assembly in a plane perpendicular to the guide plate.

10. The chainsaw according to claim 1, characterized in that, The chainsaw has an output power greater than or equal to 1000W, and / or the chainsaw has a chain speed greater than or equal to 10m / s.

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