A wheeled garden tool

Abstract

The application discloses a wheeled garden tool. The wheeled garden tool comprises a main body, a wheel, a working piece, a motor and a power supply device, the wheel is configured to support the main body, the working piece is installed to the main body and is configured to perform a garden work, the motor is configured to drive at least one of the wheel and the working piece, the power supply device is arranged on the main body and provides electric energy for at least the motor, the motor is sealed, and the equivalent thermal conductivity between the teeth of the motor is greater than or equal to 3. The sealed motor of the wheeled garden tool improves the sealing performance, so that the motor is more suitable for the working environment of the wheeled garden tool. In addition, the equivalent thermal conductivity between the teeth of the motor of the wheeled garden tool is greater than or equal to 3, so that the heat conduction speed of the motor is fast, and the heat dissipation performance is good.

Description

Technical Field

[0001] This application relates to a power tool, specifically a wheeled garden tool. Background Technology

[0002] Wheeled garden tools in related technologies are mainly power tools used for the maintenance of large areas of lawns, gardens, or landscapes, such as push lawnmowers, riding lawnmowers, push snowplows, and riding snowplows. Riding lawnmowers, as a type of wheeled garden tool, are widely used in mowing lawns and vegetation, and compared to push lawnmowers, they are less strenuous to use and more efficient. Riding snowplows, as a type of wheeled garden tool, are widely used in snow removal, and compared to push snowplows, they are less strenuous to use and more efficient.

[0003] Existing wheeled garden tools generally use electric motors as their power components. Due to insufficient sealing of the motors, and the fact that wheeled garden tools need to come into contact with complex environments such as dust, weeds, and snow during operation, these substances can easily enter the motor, leading to motor failure. Furthermore, existing wheeled garden tools generally use round wire motors, which have poor heat dissipation performance, and overheating of round wire motors can also affect motor performance.

[0004] This section provides background information related to this application, which is not necessarily prior art. Summary of the Invention

[0005] One object of this application is to solve or at least alleviate some or all of the aforementioned problems. To this end, one object of this application is to provide a wheeled garden tool that not only has good sealing properties but also good heat dissipation.

[0006] To achieve the above objectives, this application adopts the following technical solution:

[0007] A wheeled garden tool includes: a body; wheels configured to support the body; a working part mounted to the body and configured to perform gardening operations; a motor configured to drive at least one of the wheels and the working part; a power supply device disposed in the body and providing electrical energy to at least the motor; the motor is sealed and the inter-tooth equivalent thermal conductivity of the motor is greater than or equal to 3.

[0008] In some embodiments, the motor includes a stator and a rotor, the stator including a plurality of flat wire windings, the rotor being magnetically coupled to the stator and used to convert electrical energy into mechanical energy.

[0009] In some embodiments, the wheeled garden tool further includes a control unit, wherein the motor is a flat wire motor, the control unit is electrically connected to the flat wire motor, and is used to control the speed and torque of the flat wire motor.

[0010] In some embodiments, the wheeled garden tool further includes a user interface connected to the control unit, which is used to receive user-inputted operation commands and display the operating status of the wheeled garden tool.

[0011] In some embodiments, the wheel includes at least two drive wheels, which are driven by the output shaft of a motor.

[0012] In some embodiments, the wheeled garden tool is a lawnmower, and the working part is a lawnmower blade.

[0013] In some embodiments, the motor directly drives the mowing blade.

[0014] In some embodiments, the lawnmower also includes a seat disposed on the main body and for a user to sit on.

[0015] In some embodiments, the wheeled garden tool is a snowplow, and the working part is a helical blade.

[0016] In some embodiments, the motor drives the helical blades via a transmission mechanism.

[0017] In some embodiments, the torque per unit current density of the motor is greater than or equal to 2.

[0018] In some embodiments, the unit square root copper loss torque of the motor is greater than or equal to 1.3.

[0019] In some embodiments, the ratio of the maximum output torque of the motor to the stack length of the motor is greater than or equal to 0.4 Nm / mm.

[0020] In some embodiments, the voltage of the power supply device is greater than or equal to 20V and less than or equal to 80V.

[0021] In some embodiments, the power supply is a removable battery pack.

[0022] A wheeled garden tool includes: a body; wheels configured to support the body; a working part mounted to the body and configured to perform gardening tasks; a motor configured to drive at least one of the wheels and the working part; a power supply unit disposed in the body and providing electrical energy to at least the motor; the motor is sealed and the torque per unit current density of the motor is greater than or equal to 2.

[0023] A wheeled garden tool includes: a body; wheels configured to support the body; a working part mounted to the body and configured to perform gardening operations; a motor configured to drive at least one of the wheels and the working part; a power supply unit disposed in the body and providing electrical power to at least the motor; the motor is sealed and the motor has a copper loss torque greater than or equal to 1.3.

[0024] A wheeled garden tool includes: a body; wheels configured to support the body; a working part mounted to the body and configured to perform gardening operations; a motor configured to drive at least one of the wheels and the working part; a power supply device disposed in the body and providing electrical power to at least the motor; the motor is sealed and the ratio of the maximum output torque of the motor to the stack length of the motor is greater than or equal to 0.4 Nm / mm.

[0025] The advantages of this application are:

[0026] The wheeled garden tool provided in this application includes a main body, wheels, working parts, a motor, and a power supply unit. The wheels are configured to support the main body, the working parts are mounted to the main body and configured to perform gardening operations, the motor is configured to drive at least one of the wheels and the working parts, and the power supply unit is located in the main body to provide electrical power to at least the motor. The motor is sealed, and the equivalent thermal conductivity between the motor teeth is greater than or equal to 3. The sealed design of the motor in this wheeled garden tool improves sealing performance, making the motor more suitable for the working environment of wheeled garden tools. Furthermore, because the equivalent thermal conductivity between the motor teeth of this wheeled garden tool is greater than or equal to 3, the motor has a fast heat conduction speed and good heat dissipation performance. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a lawnmower;

[0028] Figure 2 This is a schematic diagram of another type of lawnmower;

[0029] Figure 3 This is a schematic diagram of the lawnmower blades;

[0030] Figure 4 This is a schematic diagram of the user interface for a lawnmower;

[0031] Figure 5 This is a schematic diagram of a snowplow;

[0032] Figure 6 This is an exploded view of the electric motor;

[0033] Figure 7 This is a schematic diagram of a flat wire winding.

[0034] 10. Lawn mower; 20. Snowplow;

[0035] 100. Main body;

[0036] 200. Wheel; 210. Front drive wheel; 220. Rear drive wheel;

[0037] 300. Workpieces;

[0038] 400. Motor; 410. Stator; 411. Stator core; 412. Flat wire winding; 413. Lead wire; 420. Rotor; 430. Housing; 440. Sealing ring;

[0039] 500. Power supply unit;

[0040] 600. Control unit;

[0041] 700. User interface;

[0042] 800. Seats. Detailed Implementation

[0043] Before explaining any implementation of this application in detail, it should be understood that this application is not limited to its application to the structural details and component arrangements set forth in the following description or shown in the above drawings.

[0044] In this application, the terms "comprising," "including," "having," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0045] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this application generally indicates that the preceding and following related objects have an "and / or" relationship.

[0046] In this application, the terms "connection," "combination," "coupling," and "installation" can refer to direct connection, combination, coupling, or installation, or indirect connection, combination, coupling, or installation. For example, a direct connection refers to two parts or components being connected together without the need for an intermediary, while an indirect connection refers to two parts or components each being connected to at least one intermediary, with the connection achieved through the intermediary. Furthermore, "connection" and "coupling" are not limited to physical or mechanical connections or couplings, but can also include electrical connections or couplings.

[0047] In this application, those skilled in the art will understand that relative terms (e.g., “about,” “approximately,” “basically,” etc.) used in conjunction with quantities or conditions are to include the values ​​and have the meaning indicated by the context. For example, such relative terms include at least the degree of error associated with the measurement of a particular value, tolerances associated with the particular value due to manufacturing, assembly, use, etc. Such terms should also be considered as disclosing a range defined by the absolute values ​​of the two endpoints. Relative terms may refer to a certain percentage (e.g., 1%, 5%, 10% or more) of the indicated value. Numerical values ​​that do not use relative terms should also be disclosed as specific values ​​with tolerances. Furthermore, “basically” when expressing relative angular relationships (e.g., substantially parallel, substantially perpendicular) may refer to a certain degree (e.g., 1 degree, 5 degrees, 10 degrees or more) added to or subtracted from the indicated angle.

[0048] In this application, those skilled in the art will understand that the function performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, the function performed by a part can also be performed by one part, one component, or a combination of multiple parts.

[0049] In this application, the directional terms "upper," "lower," "left," "right," "front," and "rear" are used to describe the orientation and positional relationships shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should be understood that when an element is mentioned as being connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected through an intermediate element. It should also be understood that directional terms such as upper side, lower side, left side, right side, front side, and rear side not only represent positive orientation but can also be understood as lateral orientation. For example, "below" can include directly below, lower left, lower right, lower front, and lower rear.

[0050] In this application, the terms "controller," "processor," "central processing unit," "CPU," and "MCU" are used interchangeably. When using the unit "controller," "processor," "central processing unit," "CPU," or "MCU" to perform a specific function, unless otherwise stated, these functions may be performed by a single or multiple of the aforementioned units.

[0051] In this application, the terms "device," "module," or "unit" are used to describe devices that can be implemented in hardware or software to perform a specific function.

[0052] In this application, the terms “calculation,” “judgment,” “control,” “determine,” “identify,” etc., refer to the operation and process of a computer system or similar electronic computing device (e.g., controller, processor, etc.).

[0053] This application discloses a wheeled garden tool, which is an electric tool capable of operating in outdoor locations such as gardens and parks. In some embodiments, such as Figure 1 and Figure 2 As shown, the wheeled garden tool is a lawnmower 10; in other embodiments, such as Figure 5 As shown, the wheeled garden tool is a snowplow 20; of course, in other embodiments, the wheeled garden tool can also be a garden tractor, a multi-functional tractor, or other electric tools.

[0054] Specifically, such as Figures 1 to 5 As shown, the wheeled garden tool includes a body 100, wheels 200, a working component 300, a motor 400, and a power supply 500. The wheels 200 support the body 100, the working component 300 is mounted to the body 100 and is used to perform gardening tasks, the motor 400 drives at least one of the wheels 200 and the working component 300, and the power supply 500 is located in the body 100 and provides electrical power to at least the motor 400. The motor 400 is sealed and has an inter-tooth equivalent thermal conductivity greater than or equal to 3.

[0055] Compared to existing wheeled garden tools, the motor 400 of the wheeled garden tool provided in this application features a sealed design, which improves sealing performance and makes the motor 400 more suitable for the working environment of wheeled garden tools. Furthermore, because the inter-tooth equivalent thermal conductivity of the motor 400 of this wheeled garden tool is greater than or equal to 3, the motor 400 exhibits fast heat conduction and excellent heat dissipation performance.

[0056] Regarding the sealing of the motor 400, in some embodiments, the motor 400 may employ a lower level of sealing, that is, ensuring that the housing 430 of the motor 400 has no holes, or it may employ a sealing method such as... Figure 6The sealing structure, including the 440 sealing ring and sealant, achieves a seal. Flat-wire motors used in garden power tools (such as lawnmowers, chainsaws, and hair dryers) typically have an IP54 or IP55 sealing rating, effectively preventing dust (level 5) and splash water (level 4) or low-pressure water jets (level 5), ensuring stable operation in dusty, humid, or rainy outdoor environments. The benefits of this sealing design include: 1) extending motor life by preventing dust and moisture intrusion that could lead to winding corrosion or short circuits; 2) improving reliability and reducing malfunctions caused by environmental impurities; and 3) strong adaptability, meeting the needs of garden tools frequently exposed to harsh working conditions while balancing cost and performance. However, this also means the motor windings are not cooled by air; the higher inter-tooth equivalent thermal conductivity allows for faster heat conduction in the motor, improving heat dissipation performance.

[0057] Regarding the equivalent thermal conductivity between the teeth of motor 400 It is a key parameter for analyzing the heat dissipation performance of the stator 410 teeth of motor 400, reflecting the comprehensive heat conduction capacity of the inter-tooth region of stator 410, and directly affecting the accuracy of the temperature rise distribution of motor 400.

[0058] The equivalent thermal conductivity perpendicular to the direction of the conductor is defined as: ;in, Equivalent thermal conductivity, expressed in W / m·K, characterizes the overall thermal conductivity of a material under specific conditions; Q is the heat flow rate, which is the amount of heat passing through the material per unit time, expressed in W. The length of the heat conduction path, such as the radial or axial thickness of the interdental region, is expressed in meters (m). Temperature difference, i.e., the temperature difference between the two ends of the material, is expressed in K. The cross-sectional area perpendicular to the heat flow direction, in units of .

[0059] In one embodiment, the inter-tooth equivalent thermal conductivity of the motor 400 is 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1, 4.2, 4.3, 4.4, or 4.5. Of course, in other embodiments, the inter-tooth equivalent thermal conductivity of the motor 400 can also be other values ​​greater than or equal to 3.

[0060] In some embodiments, continue to refer to Figure 6As shown, motor 400 is a flat wire motor. Specifically, motor 400 includes a stator 410 and a rotor 420. The stator 410 includes multiple flat wire windings 412. The rotor 420 is magnetically coupled to the stator 410 and is used to convert electrical energy into mechanical energy. Motor 400 also includes a housing 430, within which both the stator 410 and the rotor 420 are housed. The stator 410, as the key stationary part of motor 400, mainly consists of a stator core 411, flat wire windings 412, lead wires 413, and insulating material. The stator 410 is typically tightly connected to the housing 430. The rotor 420 is the rotating component of motor 400, encompassing core components such as the rotor core, permanent magnets, and shaft bearings. It drives the wheeled garden tool through its connection with the output shaft.

[0061] Continue to refer to Figure 7 As shown, the flat wire winding 412 is also known as the hairpin winding. It consists of multiple hairpin-shaped coils. The hairpin winding can accommodate more flat wires in a limited space, thereby improving the efficiency and power density of the motor 400.

[0062] The main process steps for the flat wire winding 412 include: 1. Flat wire forming: pre-bending the rectangular copper wire into a "hairpin" shape; 2. Insertion into stator slots: inserting the formed flat wire layer by layer into the stator core slot 411; 3. End welding: connecting the ends of the hairpins by laser welding or TIG welding to form a complete winding; 4. Insulation treatment: coating with insulating varnish or wrapping with insulating material.

[0063] Calculating the equivalent thermal conductivity between teeth The calculation formula varies depending on the wire type forming the winding. If the wire is circular, then... If the conductor is a flat wire, then In the two formulas mentioned above, The radial equivalent thermal conductivity of the flat wire winding 412 is expressed in W / m·K. The percentage of copper width can be approximated by the slot fill factor; The thermal conductivity of copper; Thermal conductivity of insulating materials; The radial equivalent thermal conductivity of the circular wire winding; This represents the full capacity rate.

[0064] In addition to the equivalent thermal conductivity between teeth In addition, the motor 400 also has a performance parameter of torque per unit current density. Torque per unit current density is an important indicator for measuring the motor 400. This indicator reflects the efficiency of the material or design in generating torque under the same current density. The higher the value of torque per unit current density, the better the electromagnetic design (such as a more reasonable winding, circuit or permanent magnet layout).

[0065] Specifically, torque per unit current density is the ratio of output torque T to current density J. The relationship between output torque T and current density J can be derived using the following formula:

[0066] ①、 Where T is the rotational torque output by the motor 400 or electromagnetic device, in N·m; This is the tangential stress, i.e., the electromagnetic shear stress in the air gap, with units of N / m². The rotor volume or effective working volume is 420, in units of... .

[0067] ②、 Where A is the line current density, with units of A / m; This represents the peak value of the air gap magnetic flux density, in tons (T). The phase angle (power factor angle) between the current and the magnetic field is expressed in rad (or °).

[0068] ③、 Where m is the number of phases of the motor (400); This refers to the number of conductors (turns) in series per phase. The cross-sectional area of ​​a single conductor, in meters (m²). 2 ; The inner diameter of the stator is 410, in meters (m). Current density is the current passing through a unit cross-sectional area of ​​a conductor, measured in A / m².

[0069] ④ ,in, This is the excitation voltage of stator 410; This refers to the ratio or coupling coefficient.

[0070] ⑤、 ,in, This is the inner diameter of stator 410; The outer diameter of the motor is 400.

[0071] Combining formulas ① through ⑤ above, we can derive the following formula:

[0072] ⑥、 .

[0073] In the embodiments of this application, the torque per unit current density of the motor 400 is greater than or equal to 2. In one embodiment, the torque per unit current density of the motor 400 is 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, or 4. Of course, in other embodiments, the torque per unit current density of the motor 400 can also be other values ​​within the range of greater than or equal to 2. Compared to the torque per unit current density of existing circular wire motors... Within the range of (0-2), the unit current density torque of the motor 400 provided in this application is greater than or equal to 2, thereby improving the efficiency of the motor 400.

[0074] In addition, motor 400 also has a performance parameter called square root copper loss torque, which is an important indicator of motor 400 efficiency. It represents the motor 400's ability to output torque under a given copper loss. This indicator reflects the efficiency of motor 400's output torque at the same copper loss level. A higher square root copper loss torque value indicates that motor 400 can provide greater torque under heat constraints, indicating a better design. Moreover, unlike "torque per unit current density," square root copper loss torque is directly related to heat loss (copper loss is the main source of heat generation in motor 400).

[0075] Specifically, the unit square root of the copper loss torque is the sum of the output torque T and the square root of the copper loss. The ratio of .

[0076] Regarding the output torque T and the square root of copper loss The relationship can be derived using the following formula:

[0077] ⑥、 .

[0078] ⑦、 ,in, Copper loss refers to the Joule heat loss of the 400 winding resistance of the motor due to current, and the unit is W. V is the resistivity; V is the total volume of the winding conductors, in m³. The current density of the conductor is expressed in A / m².

[0079] Combining formulas ⑥ and ⑦ above, we can derive the following formula:

[0080] ⑧、 .

[0081] In the embodiments of this application, the square root copper loss torque of the motor 400 is greater than or equal to 1.3. In one embodiment, the square root copper loss torque of the motor 400 is 1.3, 1.4, 1.5, or 1.6. Of course, in other embodiments, the square root copper loss torque of the motor 400 can also be other values ​​within the range of greater than or equal to 1.3. Compared with the prior art circular wire motors, whose square root copper loss torque is generally in the range of 1-1.2, the square root copper loss torque of the motor 400 provided in this application is greater than or equal to 1.3, thereby improving the efficiency of the motor 400.

[0082] In some embodiments, the ratio of the maximum output torque of the motor 400 to the stack length of the motor 400 is greater than or equal to 0.4 Nm / mm. In one specific embodiment, the ratio of the maximum output torque of the motor 400 to the stack length of the motor 400 is 0.4 Nm / mm, 0.45 Nm / mm, 0.5 Nm / mm, 0.55 Nm / mm, 0.6 Nm / mm, 0.65 Nm / mm, 0.666 Nm / mm, 0.7 Nm / mm, or 0.75 Nm / mm. Of course, in other embodiments, the ratio of the maximum output torque of the motor 400 to the stack length of the motor 400 can also be other values ​​within the range of 0.4 Nm / mm. Compared to the existing circular motors, where the ratio of the maximum output torque of the motor 400 to the stack length of the motor 400 is generally around 0.3 Nm / mm, the motor 400 provided in this application has a higher ratio and a more effective reduction in stack length, thereby reducing the space required to install the motor 400 and contributing to a more compact layout of garden tools.

[0083] The main body 100 is the core structure of the wheeled garden tool. It includes a chassis and an external protective frame. The chassis mounts the wheels 200, the working component 300, the motor 400, and the power supply 500, connecting them into a single unit. The external protective frame is located on the chassis, and the motor 400 and power supply 500 can be installed within it, thus protecting the components inside.

[0084] The wheel 200 includes at least two drive wheels, which are connected to the output shaft of the motor 400 to enable autonomous movement of the wheeled garden tool. The at least two drive wheels are divided into a front drive wheel 210 and a rear drive wheel 220, depending on their mounting position. The front drive wheel 210 is mounted on the front side of the chassis, and the rear drive wheel 220 is mounted on the rear side of the base plate. The number of drive wheels can be two, three, four, five, or more, depending on requirements. The drive wheels enable the wheeled garden tool to move on the ground, and at least allow it to move forward, backward, and turn on the ground.

[0085] To power the rotation of the drive wheels, the output shaft of motor 400 is connected to at least a portion of the drive wheels and is used to power the rotation of at least the drive wheels. In one embodiment, the wheeled garden tool is front-wheel drive, i.e., motor 400 rotates with the front drive wheel 210; in another embodiment, the wheeled garden tool is rear-wheel drive, i.e., motor 400 rotates with the rear drive wheel 220; in yet another embodiment, the wheeled garden tool is all-wheel drive, i.e., the power of motor 400 is transmitted to both the front drive wheel 210 and the rear drive wheel 220, driving both the front drive wheel 210 and the rear drive wheel 220 to rotate. The working part 300 is the actuating component, and in some embodiments, such as Figures 1 to 3 As shown, if the wheeled garden tool is a lawnmower 10, the working piece 300 is a lawnmower blade; in other embodiments, such as Figure 5 As shown, the wheeled garden tool is a snowplow 20, and the working part 300 is a spiral blade. It should be noted that the lawnmower 10 here can be a push-type lawnmower or a ride-on lawnmower; the snowplow 20 can be a push-type snowplow or a ride-on snowplow.

[0086] It should be noted that, for the lawnmower 10, the motor 400 driving the working component 300 can directly drive the mowing blades, causing the blades to rotate around their axis of rotation, thereby cutting vegetation; of course, the motor 400 driving the working component 300 can also be connected to the mowing blades through a transmission component. For the snowplow 20, the motor 400 driving the working component 300 can directly drive the spiral blades, causing the spiral blades to rotate around their axis of rotation, thereby sweeping snow; the motor 400 driving the working component 300 can also drive the spiral blades through a transmission mechanism. The specific structure of the transmission component and transmission mechanism is prior art and will not be described in detail here. In some embodiments, to distinguish between the motor 400 that powers the wheel 200 and the motor 400 that powers the working component 300, the motor 400 that powers the wheel 200 is defined as the first motor, and the motor 400 that powers the working component 300 is defined as the second motor.

[0087] In other embodiments, the same motor 400 serves both the driving and operation functions. This single-motor solution places special demands on the motor's efficiency characteristics: during operation, the load on the working part 300 (such as mowing or snow-sweeping resistance) and the driving load on the wheels 200 (such as ground slope and lawn friction coefficient) fluctuate independently and frequently. The combined load on the motor 400 exhibits a non-linear, wide-range variation. Compared to traditional round-wire motors, the flat-wire motor 400 demonstrates its advantages in such complex load scenarios. First, due to its flat-wire winding 412, the flat-wire motor 400 has a higher slot fill factor and lower winding resistance, significantly reducing copper losses at the same current. This means that when the motor 400 needs to output both driving and operation torque simultaneously, the flat-wire motor 400 can convert electrical energy into mechanical energy with higher efficiency, thereby reducing heat generation and avoiding heat accumulation caused by complex loads. Secondly, the flat wire motor 400 has an equivalent inter-tooth thermal conductivity of ≥3, exhibiting excellent heat dissipation performance. Even under continuous high-load combined operating conditions, the internal temperature rise of the motor can be effectively controlled within a safe range, eliminating the need for derating for heat dissipation. Thirdly, the flat wire motor 400 has a flatter efficiency curve over a wide torque range. Whether under light-load walking conditions, heavy-load working conditions, or combined conditions, the flat wire motor 400 maintains high operating efficiency, avoiding the problem of drastic efficiency drops in traditional round wire motors when the load fluctuates. Therefore, using the same flat wire motor 400 to simultaneously drive the wheel 200 and the working part 300 not only simplifies the overall structure and reduces cost and weight, but more importantly, the high efficiency, low copper loss, and excellent heat dissipation performance of the flat wire motor 400 enable it to easily cope with drastic fluctuations in combined loads, achieving long-term continuous operation while ensuring reliability. In contrast, traditional round wire motors often face problems such as overheating shutdown or insufficient range due to low efficiency when performing the same dual-task operation. The technical solution of this application overcomes these technical biases.

[0088] For user convenience, please continue to refer to... Figure 2 As shown, the lawnmower 10 also includes a seat 800, which is located on the main body 100 and is used by the user to sit.

[0089] The voltage of the power supply 500 is greater than or equal to 20V and less than or equal to 80V. In one specific embodiment, the voltage of the power supply 500 is 20V, 24V, 30V, 35V, 40V, 48V, 50V, 56V, 60V, 65V, 72V, 75V, or 80V. Of course, the voltage of the power supply 500 can also be other values ​​within the range of 20V-80V, which are not listed here. In the wheeled garden tool of this application, setting the voltage range between 20V and 80V and configuring it in conjunction with a sealed flat wire motor 400 with a specific thermal conductivity (or torque density) is the key to optimizing the overall performance of the machine. Compared with traditional round wire motors, the flat wire motor 400 has a higher slot fill factor and a shorter winding heat conduction path, thus enabling it to operate efficiently at higher current densities. However, excessively low voltage (e.g., less than 20V) will result in excessive current while ensuring the same output power. This not only increases the heat generation of the power supply unit 500 connection terminals and wiring harness, but also poses a severe challenge to the reliability of the end welding of the flat wire winding 412, failing to fully utilize the high thermal conductivity advantage of the flat wire motor. On the other hand, excessively high voltage (e.g., greater than 80V) will significantly increase the safety protection level requirements, leading to a sharp increase in the cost of the power supply unit 500 and the motor control unit 600, making it unsuitable for cost-sensitive scenarios such as garden tools. Therefore, the combination of a voltage range of 20V to 80V with the sealed flat wire motor 400 can fully utilize the high slot fill factor and excellent heat dissipation performance of the flat wire motor 400, achieving high torque output while ensuring the portability and safety of the entire machine. It can also effectively control the cost of the power management system and electrical insulation, thus achieving an ideal balance between power density, endurance, safety, and economy in wheeled garden tools.

[0090] In some embodiments, the power supply unit 500 is a removable battery pack, such as a lithium-ion battery pack. In the wheeled garden tool of this application, the power supply unit 500 adopts the form of a removable battery pack, forming a cooperative configuration with the sealed flat wire motor 400. Specifically, the flat wire motor 400 has higher efficiency and lower copper loss, requiring less discharge current from the battery pack at the same output power. This not only reduces heat generation at the battery pack connection terminals but also extends the runtime after a single charge. Simultaneously, the excellent heat dissipation performance of the sealed flat wire motor 400 allows the battery pack to discharge at a higher continuous power without triggering over-temperature protection due to excessive motor temperature rise. Furthermore, the removable battery pack design allows users to quickly replace the battery pack with a spare when the main battery is depleted, significantly reducing downtime caused by charging waits. Since the flat wire motor 400 maintains high operating efficiency over a wide voltage range (20V-80V), the same battery pack can be adapted to wheeled garden tools with different power levels, achieving cross-platform battery pack sharing and reducing user accessory costs and charging management complexity.

[0091] The wheeled garden tool also includes a control unit 600 and a flat-wire motor 400. The control unit 600 is electrically connected to the flat-wire motor and is used to control the speed and torque of the flat-wire motor. Regarding the structure of the control unit 600, it can be a centralized or distributed controller. For example, the controller can be a single microcontroller or a distribution of multiple microcontrollers. The microcontroller can run a control program to control the motor 400 and other electronic components to achieve their functions. The control unit 600 is electrically connected to the flat-wire motor 400 and configured to adjust the speed and torque of the flat-wire motor 400 in real time according to the workload of the wheeled garden tool. Compared to traditional round-wire motors, the flat-wire motor 400 has a faster electromagnetic response speed and less torque ripple, which allows the control unit 600 to dynamically adjust the motor's output characteristics with higher control precision and shorter response time. Specifically, during lawn mowing or snow shoveling operations, when the workpiece 300 encounters a sudden increase in load (such as in thick grass or hard snow), the control unit 600 can quickly increase the torque output of the flat-wire motor 400 to maintain the operating speed; when the load decreases, it promptly reduces the current to save energy. Because the flat-wire motor 400 has a higher inter-tooth equivalent thermal conductivity, even under frequent load fluctuations and instantaneous high-current surges, the internal temperature rise of the motor can be effectively controlled, allowing the control unit 600 to employ a more aggressive torque-boosting strategy without excessive concern about overheating damage. This deep synergy between the flat-wire motor 400 and the control unit 600 enables wheeled garden tools to maintain stable and efficient power output in complex and variable outdoor working environments.

[0092] The wheeled garden tool also includes a user interface 700, which is connected to the control unit 600. The user interface 700 receives user input commands and displays the operating status of the wheeled garden tool. It should be noted that the user interface 700 can be a mechanical interface, equipped with control handles, control buttons, etc. Users control the wheeled garden tool's operation by pressing the control buttons or moving / rotating the control handles, such as controlling the wheeled garden tool to move forward, backward, turn, accelerate, decelerate, start, and stop. Alternatively, the user interface 700 can be a touch-screen interface, equipped with multiple virtual buttons. Users control the wheeled garden tool's operation by touching these virtual buttons, such as controlling the wheeled garden tool to move forward, backward, turn, accelerate, decelerate, start, and stop. The user interface 700 is connected to the control unit 600, and its configuration is adapted to the performance characteristics of the flat wire motor 400. Because the flat wire motor 400 can maintain high efficiency and smooth operation over a wide speed range, the user interface 700 can provide a more simplified operating logic. For example, unlike operating tools driven by traditional round wire motors, users do not need to frequently adjust the throttle or gear to cope with load changes. The flat wire motor 400, in conjunction with the control unit 600, can automatically adapt the torque. The user interface 700 can be set with preset modes such as "Economy Mode," "Standard Mode," and "Powerful Mode." The control unit 600 automatically optimizes the motor's operating curve based on the user-selected mode and real-time feedback parameters from the flat wire motor 400 (such as current, temperature, and speed). Furthermore, the operating status information displayed on the user interface 700 can include the real-time temperature of the flat wire motor 400, the remaining battery pack range (calculated based on the flat wire motor's real-time efficiency), and fault diagnosis prompts. The low vibration and low noise characteristics of the sealed flat wire motor 400 also protect the touch or display components on the user interface 700 from high-frequency vibrations, improving interface reliability and user comfort.

[0093] The foregoing has shown and described the basic principles, main features, and advantages of this application. Those skilled in the art should understand that the above embodiments do not limit this application in any way, and all technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of this application.

Claims

1. A wheeled garden tool, comprising: Main body (100); Wheels (200) are configured to support the main body (100); The workpiece (300) is installed onto the main body (100) and configured to perform garden operations; An electric motor (400) is configured to drive at least one of the wheel (200) and the working piece (300); A power supply device (500) is disposed on the main body (100) and provides electrical energy to at least the motor (400); The characteristic is that the motor (400) is sealed and the inter-tooth equivalent thermal conductivity of the motor (400) is greater than or equal to 3.

2. The wheeled garden tool according to claim 1, characterized in that, The motor (400) includes a stator (410) and a rotor (420), the stator (410) including a plurality of flat wire windings (412), the rotor (420) being magnetically coupled to the stator (410) and used to convert electrical energy into mechanical energy.

3. The wheeled garden tool according to claim 2, characterized in that, The wheeled garden tool also includes a control unit (600) electrically connected to the motor (400) and used to control the speed and torque of the motor (400).

4. The wheeled garden tool according to claim 3, characterized in that, The wheeled garden tool also includes a user interface (700), which is connected to the control unit (600) and is used to receive user input operation commands and display the operating status of the wheeled garden tool.

5. The wheeled garden tool according to claim 1, characterized in that, The wheel (200) includes at least two drive wheels, which are driven by the output shaft of the motor (400).

6. The wheeled garden tool according to claim 1, characterized in that, The wheeled garden tool is a lawnmower (10), the working part (300) is a lawnmower blade, and the motor (400) directly drives the lawnmower blade.

7. The wheeled garden tool according to claim 1, characterized in that, The wheeled garden tool is a snowplow (20), the working part (300) is a helical blade, and the motor (400) drives the helical blade via a transmission mechanism.

8. The wheeled garden tool according to claim 1, characterized in that, The torque per unit current density of the motor (400) is greater than or equal to 2.

9. The wheeled garden tool according to claim 1, characterized in that, The unit copper loss torque of the motor (400) is greater than or equal to 1.

3.

10. The wheeled garden tool according to claim 1, characterized in that, The ratio of the maximum output torque of the motor (400) to the stack length of the motor (400) is greater than or equal to 0.4 Nm / mm.

11. The wheeled garden tool according to claim 1, characterized in that, The voltage of the power supply device (500) is greater than or equal to 20V and less than or equal to 80V.

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