Cutterhead assembly and mower

Abstract

The application relates to the technical field of lawn mowers, in particular to a cutterhead assembly and a lawn mower. The cutterhead of the cutterhead assembly is provided with a driving part, an annular supporting part and an annular mounting part from inside to outside, the supporting part is connected with the driving part in an inner ring and connected with the mounting part in an outer ring; the driving part is connected with a driving unit, the outer ring of the mounting part is provided with cutting blades, the supporting part is provided with one or more through holes, and when the cutterhead rotates, the air flow velocity on the side of the supporting part close to the ground is smaller than the air flow velocity on the side of the supporting part far from the ground. When the cutterhead rotates, the air flow velocity below is higher, an upper-lower pressure difference is formed according to the Bernoulli principle, a stable air flow from top to bottom is constructed, the upward movement of grass stems is blocked, and the broken grass stems entering the upper part of the cutterhead can be quickly discharged to the ground in cooperation with the through holes. The application effectively solves the problem of grass stem winding around the motor output end in the long-term use of the cutterhead of the lawn mower.

Description

Technical Field

[0001] This application relates to the field of lawnmower technology, and more particularly to a blade assembly and a lawnmower. Background Technology

[0002] With the increasing demand for courtyard greening and small lawn management, intelligent lawnmowers, with their autonomous navigation and automatic cutting functions, have become an important product in the field of garden machinery. Currently, most mainstream models adopt a "bottom-mounted cutter head" design: the cutter head is mounted at the bottom of the machine body, and the drive motor is located above the cutter head, transmitting power through an output shaft to cut the grass stems.

[0003] In existing technologies, the blades of intelligent lawnmowers need to contact the grass stems on the ground, and there is inevitably an assembly gap between the blade edge and the bottom of the machine body. Grass stems can easily extend into the cavity formed by the gap from the side. When the blades rotate at high speed, some broken grass stems are blown upward by centrifugal force or airflow and enter the cavity area where the motor output end is located. As the mowing operation continues, the broken grass stems will gradually become entangled in the transmission components such as the motor output shaft and coupling.

[0004] Entangled grass stems significantly increase the transmission resistance at the motor output end: on the one hand, this leads to a decrease in blade speed, reduced cutting efficiency, and even missed cuts; on the other hand, it causes the motor load to exceed the threshold, resulting in a surge in power consumption. Prolonged operation can lead to motor overheating, shortened lifespan, and in severe cases, stalling and shutdown, affecting operational stability and reliability. Current technologies, such as conventional grass-blocking structures, only prevent bottom grass stems from splashing and cannot prevent short grass stems from entering the transmission area upwards. No effective solution has yet been developed, necessitating optimization of the intelligent lawnmower cutting system structure. Summary of the Invention

[0005] The purpose of this application is to overcome at least one of the shortcomings of the prior art and to provide a blade assembly and a lawnmower to solve the problem that grass stems gradually wrap around the motor output end of the lawnmower blade under long-term use.

[0006] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description or may be learned by practice of this application.

[0007] According to one aspect of this application, a cutter head assembly is provided, which mainly includes a cutter head. The cutter head is provided with a drive unit, an annular support unit, and an annular mounting unit arranged sequentially from the inside to the outside. The inner ring of the support unit is connected to the drive unit, and the inner ring of the mounting unit is connected to the outer ring of the support unit. The drive unit is used to connect to the drive unit of a lawnmower, and the outer ring of the mounting unit is equipped with cutting blades. The support unit is provided with one or more through holes, and when the cutter head rotates, the air velocity on the side of the support unit closer to the ground is less than the air velocity on the side of the support unit farther from the ground.

[0008] In this type of embodiment, one or more through holes are provided on the support to quickly discharge a small amount of broken grass stems into the area below the cutter head, i.e., closer to the ground, when they enter the area above the cutter head during the cutting operation, rather than leaving them in the cavity between the cutter head and the bottom of the machine body, thereby reducing the probability of the grass stems coming into contact with the transmission components of the drive unit.

[0009] By ensuring that the airflow velocity on the side of the support unit closer to the ground is lower than that on the side farther from the ground, a low-pressure zone is formed below the support unit and a high-pressure zone is formed above it, naturally creating a stable airflow from top to bottom, according to Bernoulli's principle. This airflow can directly act on the broken grass stems above the cutter head, preventing them from being dispersed towards the drive unit area due to centrifugal force or turbulence, thus blocking the upward accumulation path of the grass stems from the power source.

[0010] The support unit has a ring structure with the inner ring connecting the drive unit and the outer ring connecting the mounting unit. The structure surrounding the drive unit makes the support unit form a closed physical barrier, which can directly block grass stems from extending into the drive unit area from the side gaps, thus playing a first-line protection role. Combined with the aforementioned airflow guidance and grass discharge through holes, a dual protection mechanism of physical blocking and airflow guidance is formed, which can significantly reduce or even avoid grass stems entanglement in the drive unit.

[0011] The above-mentioned effects effectively solve the problems of increased transmission resistance, reduced blade speed, increased motor power consumption and overheating caused by grass stem entanglement in existing lawnmowers. It can ensure stable blade speed and no reduction in cutting efficiency, while avoiding motor overload, extending motor life, and ultimately improving the operational stability and long-term reliability of lawnmowers.

[0012] In some example embodiments of this application, based on the aforementioned scheme, the side of the support portion away from the ground is the outer wall, which is conical in shape and gradually moves away from the ground in a direction close to its axis. The ratio of the surface area of ​​the support portion away from the ground to the surface area of ​​the support portion near the ground is i, where i < 1.

[0013] In this type of embodiment, the ratio of the surface area of ​​the support part near the ground to the surface area of ​​the support part away from the ground is designed such that the lower surface area of ​​the support part is larger than the upper surface area. When the cutter head rotates with the drive unit, the lower surface has a larger area and more contact with the air, and the air velocity is significantly higher than that of the upper surface, which satisfies the principle of forming an air pressure difference.

[0014] The conical outer wall forms a guide surface that slopes outward from the drive unit. When a small amount of broken grass stems come into contact with the solid area of ​​the support unit, the inclined conical outer wall can physically block and guide the grass stems. Under the action of their own gravity and the centrifugal force of the rotating cutter head, the grass stems will slide along the conical inclined surface towards the outer ring of the support unit away from the drive unit, rather than gathering towards the axial area where the drive unit is located. This further cuts off the possibility of grass stems contacting the drive unit transmission components from a spatial path. This complements the airflow guidance and through-hole grass discharge mechanism, creating a more comprehensive grass stem protection barrier and further reducing the risk of the drive unit being entangled by grass stems.

[0015] At the same time, the tapered structure design can increase the solid volume of the support part under the same horizontal space ratio, thereby effectively improving the overall structural strength of the support part. This structural setting can effectively offset the weakening effect of the through hole on the structural integrity of the support part, and resolve the contradiction between the through hole drainage requirements and the strength requirements of the support part.

[0016] Similarly, based on the increased structural strength, the proportion of the through holes can be further increased. A larger proportion of the through hole unit area can increase the amount of grass stems that can be accommodated and discharged in a single airflow cycle, improve the efficiency of broken grass stems being discharged downward through the through holes, and at the same time avoid deformation or breakage of the support part during high-speed rotation due to excessive opening of through holes. This achieves synergistic optimization of structural stability and grass discharge efficiency, and further enhances the protection effect on the drive part.

[0017] In some example embodiments of this application, based on the aforementioned scheme, the side of the support near the ground is the inner wall. In any section passing through the axis of the outer wall and not intersecting with the through hole, the projection of the outer wall is a straight line, and the projection of the inner wall is an arc, and the length of the arc is greater than the length of the straight line.

[0018] In this type of embodiment, the outer wall projection is a straight line. On the one hand, this ensures the regularity of the conical outer wall of the support part and avoids dead corner areas such as depressions and corners on the conical surface due to irregular cross-sectional shape. Broken grass stems, grass clippings, etc. are difficult to adhere and accumulate on the smooth straight wall surface. This can prevent foreign objects from adhering and increasing the rotation load of the cutter head, and maintain the overall mass balance of the cutter head, avoiding the impact of mass deviation on cutting stability. On the other hand, the straight cross-section is easy to process and shape, and the tilt angle of the conical outer wall can be precisely controlled to ensure the guiding effect of the conical structure on the grass stems, further reducing the probability of the grass stems approaching the drive part.

[0019] The inner wall projection is curved, and the length of the curve is greater than the straight length of the outer wall, creating a longer airflow path inside the support section. When the cutter head rotates, the air flowing along the curved inner wall is less prone to turbulence, and the flow velocity is more easily maintained stable. Compared to a straight inner wall, this allows for a more continuous and efficient creation of a low-pressure area below the support section, forming a more stable pressure difference with the high-pressure area above the support section. This stable pressure difference enhances the intensity of the directional airflow from top to bottom, not only more effectively entraining broken grass stems entering above the cutter head and quickly expelling them to the ground through the through-holes, but also preventing grass stems from stagnating due to airflow turbulence, further reducing the possibility of grass stems contacting the drive unit and improving the protection effectiveness of the drive unit.

[0020] The straight outer wall solves the problems of foreign object adhesion and the precision of the conical structure, while the curved inner wall solves the problems of airflow stability and low-pressure zone strength. Together, they ensure that during the rotation of the cutter head assembly, the regular conical surface can prevent grass stems from approaching the drive unit, while the stable airflow combined with the through holes can efficiently remove grass. At the same time, the stable airflow environment can improve the efficiency of the through holes in removing broken grass stems, indirectly reducing the accumulation of grass stems in the solid area of ​​the support unit, further optimizing the operating resistance of the cutter head assembly, and avoiding problems such as increased load on the drive unit and speed fluctuations caused by grass stem interference, thus comprehensively improving the operational stability and service life of the lawnmower.

[0021] In some example embodiments of this application, based on the aforementioned scheme, the support includes a detachably connected upper shell and a lower shell. The side of the upper shell away from the lower shell is the outer wall, and the side of the lower shell away from the upper shell is the inner wall. The upper shell is provided with a first through hole, and the lower shell is provided with a second through hole. The first through hole and the second through hole communicate to form a through hole.

[0022] In this type of embodiment, the detachable upper and lower shells are designed with independent processing. The outer wall's conical shape and the inner wall's arc shape can be processed separately using appropriate processing techniques. There is no need to consider the mutual interference between the processing of the inner and outer walls in the integrated structure. This can effectively improve the accuracy of the outer wall's conical shape and the inner wall's arc contour, ensuring the stable realization of subsequent airflow guidance and grass stem anti-adhesion functions.

[0023] The upper and lower shells can be processed in parallel. For example, the upper and lower shells can be processed simultaneously on the same production line. Compared with the serial process of processing the outer wall first, then the inner wall, and finally the through hole in the integrated support part, the processing cycle of a single support part can be greatly shortened. At the same time, the through hole is divided into the first through hole and the second through hole. The holes can be precisely drilled on the upper and lower shells according to the size and position requirements of the through hole. There is no need to process deep holes or complex angle holes on the thick-walled parts of the integrated structure, which reduces the processing difficulty and further improves the processing efficiency.

[0024] Understandably, compared to an integrated support structure, modular manufacturing eliminates the need for complex molds or specialized equipment to achieve irregularly shaped inner and outer walls. The manufacturing molds or blanking structures for modular upper and lower shells are simpler, resulting in lower manufacturing costs. Furthermore, when a component malfunctions, only the corresponding component needs to be replaced, without replacing the entire support structure. This improves the interchangeability of parts and significantly reduces maintenance costs. This solution effectively achieves a balance between cost control and enhanced functionality.

[0025] In some example embodiments of this application, based on the aforementioned scheme, the cutter head assembly further includes an extension wall, which is vertically disposed between the upper shell and the lower shell; both ends of the extension wall are respectively connected to the inner wall of the first through hole and the inner wall of the second through hole; or the extension wall is integrally formed with the lower shell and extends upward, with the extended end of the extension wall abutting against the upper shell; or the extension wall extends at least partially into the first through hole, and the outer wall of the extension wall is adapted to the first through hole; or the extension wall is integrally formed with the upper shell and extends downward, with the extended end of the extension wall abutting against the lower shell; or the extension wall extends at least partially into the second through hole, and the outer wall of the extension wall is adapted to the second through hole.

[0026] In this type of embodiment, the extended walls are connected to the inner walls of the first and second through holes, respectively, which can accurately align and fix the relative positions of the two through holes, avoiding the problems of misalignment of through holes and uneven communication gaps caused by positioning deviations during the assembly of the upper and lower shells. This design can form a regular and continuous through hole channel, ensuring that the directional airflow can be smoothly guided through the through holes when the cutter head rotates, and that broken grass stems can be stably discharged along the communication channel. At the same time, it increases the connection strength between the upper and lower shells and ensures the integrity of the through holes.

[0027] The extension wall connects the upper and lower shells through the inner wall of the through hole, eliminating the need for high-precision fitting between the inner wall of the upper shell and the outer wall of the lower shell. The upper shell can independently complete the machining of its outer wall and the first through hole, and the lower shell can independently complete the machining of its inner wall and the second through hole, without needing to consider the fitting accuracy of the non-through hole areas of the two shells. This reduces the fitting and calibration steps in the machining process and lowers the machining difficulty.

[0028] Because the upper and lower shells do not need to be connected through surface-to-surface bonding in non-through-hole areas, the wall thickness or volume of these areas can be reduced, eliminating the need for redundant material for adaptation. Furthermore, the extension wall only surrounds the through-hole, providing structural support only at necessary connection points, avoiding the additional material consumption required for integral structures or large-area bonding connections, thus reducing the total material usage of the support component. Simultaneously, the connection method between the extension wall and the inner wall of the through-hole allows for lightweight design while simultaneously reinforcing the structure around the through-hole through the extension wall, compensating for any potential decrease in support strength due to material reduction. This ensures sufficient structural stability under high-speed rotation and cutting loads, meeting the strength requirements of the cutter head during long-term operation.

[0029] The lightweight design of the support section reduces the overall weight of the cutter head, decreases inertial resistance during cutter head rotation, and thus reduces the start-up and operating load of the lawnmower drive unit. The extension wall and the upper and / or lower shell are integrally molded, which eliminates splicing gaps between components and stress concentration points during assembly, making the extension wall and the upper / lower shell a continuous structural unit.

[0030] The one-piece molding structure can eliminate the splicing gaps between components and the stress concentration points during assembly, so that the extension wall and the upper / lower shell form a continuous structural whole. This can effectively avoid problems such as cracking and deformation at the connection between the extension wall and the inner wall of the through hole due to uneven stress.

[0031] As a high-speed rotating component, the uniformity of the cutter head's mass distribution directly affects the lawnmower's operational stability. When the extension wall is integrally formed with the upper / lower shell, precision molding can ensure the dimensional accuracy, positional accuracy, and uniformity of material density of the extension wall, avoiding mass eccentricity caused by part tolerances and assembly gaps during separate assembly. This design ensures that the overall center of mass of the cutter head is highly aligned with the output shaft axis of the drive unit, reducing centrifugal force deviation during cutter head rotation. This reduces vibration and noise during lawnmower operation, avoids increased transmission losses in the drive unit and blade cutting trajectory deviation caused by vibration, and extends the service life of the drive unit.

[0032] The extension walls are integrally formed with the lower or upper shell, inheriting the advantages of the integrally formed structure with no splicing gaps and strong resistance to deformation. This can prevent the failure of the through hole connection due to the fracture of the connection between the extension wall and the lower shell or the lower shell under stress.

[0033] In some example embodiments of this application, based on the aforementioned scheme, the upper shell is connected to the outer ring of the drive unit and the inner ring of the mounting unit, respectively, and the lower shell is detachably connected to the mounting unit and / or the drive unit.

[0034] In this type of embodiment, the upper shell uses the outer ring of the drive section and the inner ring of the mounting section as dual assembly references, which can accurately locate its relative position with the core component; when the lower shell is detachably connected to the mounting section / drive section, it can use the same drive section and mounting section as assembly references to avoid positioning deviations caused by multiple reference adaptations and improve the overall assembly accuracy of the upper shell, lower shell and drive section and mounting section.

[0035] In some example embodiments of this application, based on the aforementioned scheme, the cone angle α of the outer wall is between 72° and 84°, and the ratio i of the surface area of ​​the support part near the ground to the surface area of ​​the support part away from the ground satisfies 0.5≤i<1.

[0036] In this type of embodiment, when the outer wall cone angle α is in the range of 72° to 84°, it balances the guidance of grass stems with the adaptability of the structural space. Limiting the outer wall cone angle to the range of 72° to 84° can precisely avoid the technical defects caused by angle deviation: when α > 84°, the slope of the outer wall of the cone is insufficient, and the inclined surface tends to be gentle. After the grass stems come into contact with the outer wall, they are easy to stay on the wall surface or move towards the drive part along the gentle surface, which cannot effectively play the role of tilting guidance and preventing approach; when α < 72°, the slope of the outer wall of the cone is too large, which will lead to a significant increase in the axial space occupied by the support part. This may not only cause layout interference with other components inside the lawnmower body, but also increase the overall height of the cutter head, affecting the lawnmower's passability in low lawns or complex terrain. The conical angle range of 72° to 84° ensures that the outer wall has sufficient slope, allowing the grass stems entering the solid area of ​​the support to slide quickly down the inclined wall, reducing the probability of them approaching the drive unit. It also strictly controls the axial dimensions of the support, adapting to the compact internal structure layout of the lawnmower and avoiding spatial interference problems.

[0037] In this type of embodiment, the setting range of the outer wall cone angle α can achieve a balance between the outer wall's grass-guiding function and the axial space of the cutter head. When α > 84°, the outer wall slope is too small, which cannot effectively guide the grass stems in the solid area of ​​the contact support part away from the drive part, thus weakening the grass-guiding effect; when α < 72°, the axial space occupied by the cutter head will increase significantly, compromising the overall compactness of the lawnmower's structure. This angle range, i.e., 72° to 84°, ensures that the outer wall has a reliable grass-guiding function without adding extra axial space burden to the cutter head, thus balancing functional practicality and structural rationality.

[0038] The surface area ratio i, set within the range of 0.5 ≤ i < 1, allows for precise control of the curvature of the inner wall of the support section. This prevents the inner wall from exceeding the horizontal plane of the outer ring due to excessive curvature, thus preventing unnecessary interference between the inner wall and the ground or other objects during the cutting process and ensuring smooth cutting operations. Simultaneously, this ratio range maintains a stable pressure difference between the upper and lower surfaces of the support section, ensuring that the airflow guidance effect from top to bottom is not affected. This achieves a dual balance between structural interference protection and airflow grass removal, meeting the comprehensive performance requirements of the cutter head assembly.

[0039] In some example embodiments of this application, based on the aforementioned scheme, multiple through holes are set and arranged in an array around the axis of the support, and a beam is formed between adjacent through holes. On the horizontal projection plane, with the projection of the axis of the support as the center, the maximum central angle β of any through hole relative to the center of the circle is 75°≤β≤105°.

[0040] In this type of embodiment, the beams formed between adjacent through holes are distributed in an array. Combined with a central angle setting of 75°≤β≤105°, the number of beams in the circumferential direction of the support can be stabilized at 3 to 4, forming a uniform distributed support structure. This structure can effectively connect the inner and outer rings of the support, evenly distributing the reaction force generated when the blade cuts the grass stem to each beam, avoiding deformation or displacement of the installation part due to concentrated force, ensuring that the blade always maintains a stable cutting trajectory, directly guaranteeing the grass cutting effect, and at the same time solving the problem of weak support caused by a single through hole or non-array beams, improving the overall deformation resistance of the support.

[0041] A β ≥ 75° setting ensures that the opening angle of each through hole on the horizontal projection plane is large enough, preventing grass stems from breaking due to excessively narrow openings, especially longer grass stems, which could lead to blockage or obstruction of discharge. This ensures that broken grass stems can be quickly discharged through the through holes to the bottom of the cutter head, reducing the risk of grass stems getting stuck and entangled in the drive unit by adjusting the size of the discharge channel. A β ≤ 105° setting avoids the problem of fewer than 3 beams due to excessively large through hole openings, preventing single-point support or uneven stress in the support unit due to insufficient beams. Three or more beams can form a triangular stable support structure or a multi-angle balanced support, ensuring the structural stability of the support unit under the centrifugal force of the high-speed rotation of the cutter head and the reaction force of the blade cutting. This prevents the beams from breaking or deforming due to overload, achieving a precise balance between a sufficiently large grass discharge channel and a sufficiently stable support structure.

[0042] In some example embodiments of this application, based on the aforementioned scheme, multiple blades are provided, and in the horizontal projection plane, the blades at least partially overlap with the beam in the radial direction of the support.

[0043] In the horizontal projection plane, the blade and the beam at least partially overlap in the radial direction of the support, allowing the radial load to be directly transmitted along the beam. The beam, as a solid support structure between adjacent through holes, is the core load-bearing unit of the support, possessing stronger resistance to deformation and fracture. Compared to the offset radial position of the blade from the beam, this design avoids load concentration on weak points in the support, reducing the risk of cracking and deformation due to excessive local stress, and ensuring the overall structural integrity of the cutterhead.

[0044] The array-like support structure formed by adjacent through holes in the beam system functions to connect the inner and outer rings of the support section and to distribute torque and radial force. The blades and beams radially coincide, allowing the radial force generated during cutting to be quickly transmitted through the beams to the inner and outer rings of the support section, and then further to the drive unit and the machine body, forming a closed-loop force distribution system where the blades bear the force, the beams support the load, and the force is distributed throughout the entire area. This closed loop effectively reduces the load on the non-load-bearing areas of the cutterhead, avoids cutterhead structural fatigue caused by localized overload, significantly improves the wear resistance of the cutterhead assembly, and extends its overall service life, making it particularly suitable for long-term operation in complex lawns.

[0045] In some example embodiments of this application, based on the aforementioned scheme, multiple blades are provided, and in the horizontal projection plane, the blades at least partially overlap with the beam in the radial direction of the support.

[0046] According to one aspect of this application, a lawnmower is provided, the cutting device of which includes a blade assembly as described above.

[0047] By incorporating the aforementioned blade assembly, this lawnmower can effectively reduce the accumulation and entanglement of grass stems in the drive area during mowing by fully utilizing the multi-hole chip removal and airflow guidance design of the blade assembly. At the same time, it ensures the overall structural strength and rotational stability of the blade assembly. If equipped with a cutting device containing a drive unit, it can directly utilize the protection mechanism of the blade assembly for the drive unit to avoid problems such as reduced speed, increased power consumption, or overheating caused by grass stem entanglement. Ultimately, this achieves stable cutting efficiency, extended component lifespan, and significantly improved operational reliability.

[0048] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0049] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0050] Figure 1 A top view schematic diagram of a cutter head provided in one embodiment of this application is shown.

[0051] Figure 2 The diagram shows a bottom view of a cutter head provided in one embodiment of this application.

[0052] Figure 3 A cross-sectional schematic diagram of a cutter head provided in one embodiment of this application is shown.

[0053] Figure 4 An exploded view of a cutterhead provided in one embodiment of this application is shown.

[0054] Figure 5 This illustration shows a three-dimensional structural diagram of the lower shell of a cutter head according to an embodiment of this application.

[0055] Figure 6 A cross-sectional schematic diagram of a cutter head provided in another embodiment of this application is shown.

[0056] The above figures include the following reference numerals: 10. Drive unit; 20. Support unit; 21. Through hole; 22. Upper shell; 221. First through hole; 23. Lower shell; 231. Second through hole; 24. Extension wall; 25. Beam; 30. Mounting unit; 40. Blade. Detailed Implementation

[0057] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0058] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0059] In the description of the embodiments of this application, the technical terms "first," "second," "third," "fourth," "fifth," etc., are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0060] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0061] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects are in an "or" relationship.

[0062] In the description of the embodiments of this application, the technical terms "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed, operated or used in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0063] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0064] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical term "contact" should be interpreted broadly, and can be direct contact, contact through an intermediate medium layer, contact between two contacting parties with substantially no interaction force, or contact between two contacting parties with interaction force.

[0065] To address the problem in existing lawnmowers where grass stems gradually become entangled around the motor output end after prolonged use, this application proposes a blade assembly, a cutting device, and a lawnmower that can discharge grass stems from the blade assembly, preventing entanglement in the drive unit. The following embodiments are provided to detail the various embodiments of this application.

[0066] Please see Figures 1 to 4 According to one aspect of this application, a blade disc assembly is provided for use in a lawnmower. The assembly mainly includes a blade disc, from which a drive unit 10, an annular support unit 20, and an annular mounting unit 30 are sequentially arranged from the inside out. The inner ring of the support unit 20 is connected to the drive unit 10, and the inner ring of the mounting unit 30 is connected to the outer ring of the support unit 20. The drive unit 10 is used to connect to the drive unit of the lawnmower, and a cutting blade 40 is mounted on the outer ring of the mounting unit 30. When the blade disc rotates, the airflow velocity on the side of the support unit 20 closer to the ground is less than the airflow velocity on the side of the support unit 20 farther from the ground.

[0067] In this type of embodiment, when a small amount of debris such as broken grass stems enters above the cutter head due to the cutting operation, the debris is quickly discharged to the bottom of the cutter head through the through holes 21 on the support part 20 under the action of the airflow difference between the upper and lower surfaces of the support part 20, instead of remaining in the cavity above the cutter head and the bottom of the machine body, thus reducing the probability of grass stems contacting the transmission components of the drive unit.

[0068] The air velocity on the side of the support section 20 closer to the ground is lower than the air velocity on the side of the support section 20 farther from the ground. According to Bernoulli's principle, a low-pressure area is formed below the support section 20 and a high-pressure area is formed above it, naturally creating a stable airflow from top to bottom. This airflow can directly act on the broken grass stems and other debris above the cutter head, causing them to fall downwards through the through-hole 21, preventing them from being dispersed towards the area of ​​the drive section 10 by centrifugal force or turbulence, thus blocking the upward accumulation of grass stems and other debris at the source.

[0069] The support part 20 has a ring structure with the inner ring connected to the drive part 10 and the outer ring connected to the mounting part 30. The structure surrounding the drive part 10 makes the support part 20 form a closed physical barrier, which can directly block grass stems from extending into the area of ​​the drive part 10 from the side gap, thus playing a first-line protection role. Combined with the aforementioned airflow guidance and grass discharge through hole 21, a dual protection mechanism of physical blocking and airflow guidance is formed, which can significantly reduce or even avoid grass stems entanglement with the drive unit.

[0070] The above-mentioned effects effectively solve the problems of increased transmission resistance, reduced blade speed, increased motor power consumption and overheating caused by grass stem entanglement in existing lawnmowers. It can ensure stable blade speed and no reduction in cutting efficiency, while avoiding motor overload, extending motor life, and ultimately improving the operational stability and long-term reliability of lawnmowers.

[0071] In some exemplary embodiments of this application, there are multiple ways to achieve a lower airflow velocity on the side of the support 20 closer to the ground than on the side of the support 20 farther from the ground, as follows: In some alternative solutions, the surface area is differentiated by setting the upper and lower solid parts differently. That is, the air velocity on the side of the support 20 closer to the ground is less than the air velocity on the side of the support 20 farther from the ground. Specifically, the solid part of the upper surface of the support 20 can be a planar structure, and the solid part of the lower surface of the support 20 can be a curved structure. Through the above structural settings, the fluid velocity on the upper surface is less than the fluid velocity on the lower surface, thereby forming an air pressure difference.

[0072] In some alternative solutions, the structures are similar but the parameters are different. For example, when both the upper and lower surfaces are conical surfaces, the axes of the conical surfaces of each solid part on the upper surface coincide, while the axes of the conical surfaces of each solid part on the lower surface do not coincide, and the curvature of the conical surface on the lower surface is greater than that of the conical surface on the upper surface.

[0073] The examples provided are for reference only, and the above embodiments are not limited to the alternative implementation schemes.

[0074] See 1 and Figure 2 In one specific embodiment, the drive unit 10 is located in the central area of ​​the cutter head and has a disc-shaped structure. A structure for connecting the lawnmower drive unit is provided above it, and the connection is achieved through a fastener-fitting snap-fit ​​method. The drive unit 10 and the inner ring of the support unit 20 can be an integral structure or connected by welding or other methods to ensure their coaxiality. Similarly, the inner ring of the mounting unit 30 and the outer ring of the support unit 20 can be an integral structure or connected by welding or other methods to ensure their coaxiality.

[0075] In some alternative solutions, the outer ring of the support part 20 can be a complete circular ring structure, and / or the inner ring of the support part 20 can be a complete circular ring structure. Such a structural arrangement can increase the connection area between its inner and outer rings and the mounting part 30 or the driving part 10, thereby increasing the connection strength. At the same time, the circular ring structure can also enhance its own structural strength, thus meeting the driving requirements of the high-speed rotation of the cutter head.

[0076] In some alternative solutions, the outer ring of the through hole 21 of the support part 20 can be open, with the opening directly facing the mounting part 30, and / or the inner ring of the through hole 21 of the support part 20 can be open, with the opening directly facing the driving part 10. Such a configuration results in multiple solid parts of the support part 20, which directly connect the mounting part 30 and the driving part 10, making the structure more streamlined.

[0077] Understandably, to maintain a stable horizontal height during grass cutting and to avoid the formation of fine grass clippings from repeated cuts, the mounting part 30 needs to be a planar annular structure. Similarly, to ensure that the rotation axis of the cutter head is perpendicular to the mounting part 30 and to ensure balance, the drive part 10 also needs to be a planar annular structure, and the drive part 10 and the mounting part 30 are arranged parallel to each other.

[0078] Please see Figure 3 In some example embodiments of this application, based on the aforementioned scheme, the side of the support 20 away from the ground is an outer wall, which is conical in shape and gradually moves away from the ground in a direction close to its axis. The ratio of the surface area of ​​the support 20 away from the ground to the surface area of ​​the support 20 near the ground is i, where i < 1.

[0079] In this type of embodiment, the conical outer wall forms a guide structure that slopes outward from the drive unit 10. When a small number of broken grass stems come into contact with the solid area of ​​the support unit 20, the inclined conical outer wall can physically block and guide the grass stems: under the combined action of their own gravity and the centrifugal force of the rotating cutter head, the grass stems will slide along the conical inclined surface towards the outer ring of the support unit 20 to move away from the drive unit 10, rather than gathering towards the axial area where the drive unit 10 is located, further blocking the contact path between the grass stems and the transmission components of the drive unit from a spatial perspective. This mechanism complements the airflow guidance combined with the grass discharge through the through-hole 21, constructing a more comprehensive grass stem protection barrier and further reducing the risk of the drive unit 10 being entangled by grass stems.

[0080] Meanwhile, under the condition of the same horizontal space ratio, the tapered structure design can increase the solid volume of the support part 20, thereby effectively improving the overall structural strength of the support part 20. This design can effectively offset the weakening effect of the through hole 21 on the structural integrity of the support part 20, and resolve the contradiction between the grass drainage requirements of the through hole 21 and the strength requirements of the support part 20.

[0081] Similarly, based on the improvement of structural strength, the proportion of the through hole 21 can be further increased: a larger proportion of the through hole 21 per unit area can increase the amount of grass stems that can be accommodated and discharged in a single airflow cycle, thereby improving the efficiency of the broken grass stems being discharged downward through the through hole 21; at the same time, it can avoid the support part 20 from deforming or breaking during high-speed rotation due to excessive opening of the through hole 21, and finally achieve synergistic optimization of structural stability and grass discharge efficiency, further strengthening the protective effect on the drive part 10.

[0082] In a preferred embodiment, the ratio of the surface area of ​​the support portion 20 on the side away from the ground to the surface area of ​​the support portion 20 on the side closer to the ground, i, can be in the range of 0.6 ≤ i < 1.

[0083] In a preferred embodiment, the ratio of the surface area of ​​the support portion 20 on the side away from the ground to the surface area of ​​the support portion 20 on the side closer to the ground can be i, i = 0.855.

[0084] Optionally, the specific ratio i can be 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.61, 0.62, 0.63, or 0. 64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.7, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.8, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.9, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, etc., but not limited to these.

[0085] Please see Figure 3 In some example embodiments of this application, based on the aforementioned scheme, the side of the support 20 closest to the ground is the inner wall. In any cross-section that passes through the axis of the outer wall and does not intersect with the through hole 21, the projection of the outer wall is a straight line, and the projection of the inner wall is an arc, and the length of the arc is greater than the length of the straight line.

[0086] In this type of embodiment, the outer wall projection is a straight line. On the one hand, this ensures the regularity of the conical outer wall of the support part 20, avoiding dead corners such as depressions and corners on the conical surface due to irregular cross-sectional shape. Broken grass stems and grass clippings are difficult to adhere and accumulate on the smooth straight wall surface. This can prevent foreign objects from adhering and increasing the rotation load of the cutter head, and also maintain the overall mass balance of the cutter head, avoiding the impact of mass deviation on cutting stability. On the other hand, the straight cross-section has the convenience of processing, and the tilt angle of the conical outer wall can be precisely controlled to ensure the guiding effect of the conical structure on the grass stems, further reducing the probability of the grass stems approaching the drive part 10. The inner wall projection is curved, and the length of the curve is greater than the straight length of the outer wall, creating a longer airflow path inside the support section 20. When the cutter head rotates, the air flowing along the curved inner wall is less prone to turbulence, and the flow velocity is more easily maintained stable. Compared to a straight inner wall, this structure can more continuously and efficiently create a low-pressure area below the support section 20, forming a more stable pressure difference with the high-pressure area above the support section 20. This stable pressure difference can enhance the intensity of the directional airflow from top to bottom, not only more effectively entraining broken grass stems entering above the cutter head and quickly expelling them to the ground through the through-hole 21, but also preventing grass stems from being trapped due to airflow turbulence, further reducing the possibility of grass stems contacting the drive section 10 and improving the protection effectiveness of the drive unit. The straight outer wall specifically addresses the issues of foreign object adhesion and the precision of the conical structure, while the curved inner wall solves the problems of airflow stability and low-pressure zone strength. Their combined effect ensures that during the rotation of the cutter head assembly: the regular conical surface prevents grass stems from approaching the drive unit 10, while stable airflow, in conjunction with the through-holes 21, achieves efficient grass removal. Simultaneously, the stable airflow environment improves the efficiency of the through-holes 21 in removing broken grass stems, indirectly reducing grass stem accumulation in the solid area of ​​the support unit 20. This further optimizes the operating resistance of the cutter head assembly, avoiding problems such as increased load on the drive unit and speed fluctuations caused by grass stem interference, thus comprehensively improving the operational stability and service life of the lawnmower. In some alternative embodiments, in any cross-section passing through the outer wall axis and not intersecting with the through hole 21, the projection of the outer wall is a straight line, and the projection of the inner wall is an arc or a smooth curve. It can be understood that arcs and smooth curves facilitate machining operations in actual production, allow for parameterized settings, and do not generate excessive frictional resistance during rotation.

[0087] Please see Figure 3 and Figure 4 In some example embodiments of this application, based on the aforementioned scheme, the support part 20 includes an upper shell 22 and a lower shell 23 that are detachably connected. The side of the upper shell 22 away from the lower shell 23 is the outer wall, and the side of the lower shell 23 away from the upper shell 22 is the inner wall. The upper shell 22 is provided with a first through hole 221, and the lower shell 23 is provided with a second through hole 231. The first through hole 221 and the second through hole 231 communicate to form a through hole 21.

[0088] In this type of embodiment, the upper shell 22 and lower shell 23 are designed to be detachably connected. Their processing does not interfere with each other. Adaptive processing techniques can be used for the outer wall conical forming and the inner wall arc forming, without worrying about the mutual interference between the inner and outer wall processing in the integrated structure. This can effectively improve the accuracy of the outer wall conical shape and the contour of the inner wall arc, ensuring the stable performance of subsequent airflow guidance and grass stem anti-adhesion functions.

[0089] The upper shell 22 and the lower shell 23 can be manufactured in parallel, meaning they can be processed simultaneously on the same production line. Compared to the integrated support part 20, which requires processing the outer wall first, then the inner wall, and finally the through hole 21, this design significantly shortens the processing cycle of a single support part 20. Furthermore, the through hole 21 is divided into a first through hole 221 and a second through hole 231, which are processed separately. This allows for precise drilling on the upper and lower shells 23 based on the size and location requirements of the through hole 21, eliminating the need to machine deep holes or complex angled holes on thick-walled, integrated components. This reduces processing difficulty and further improves processing efficiency.

[0090] Understandably, compared to the integrated support unit 20, the split manufacturing process eliminates the need for complex molds or specialized equipment to achieve irregularly shaped inner and outer walls. The manufacturing molds and material cutting structures for the split upper shell 22 and lower shell 23 are simpler, resulting in lower manufacturing costs. Furthermore, when a single component fails, only the corresponding component needs to be replaced, eliminating the need to replace the entire support unit 20. This improves component interchangeability and significantly reduces maintenance costs. This solution effectively achieves a balance between cost control and enhanced functionality.

[0091] Please see Figure 3 and Figure 5 In some example embodiments of this application, based on the aforementioned scheme, the cutter head assembly further includes an extension wall 24, which is vertically disposed between the upper shell 22 and the lower shell 23. The two ends of the extension wall 24 are respectively connected to the inner wall of the first through hole 221 and the inner wall of the second through hole 231, so that the first through hole 221 communicates with the second through hole 231.

[0092] In this type of embodiment, the extension wall 24 is connected to the inner walls of the first through hole 221 and the second through hole 231 respectively, which can accurately align and fix the relative positions of the two through holes 21, effectively avoiding problems such as misalignment of through holes 21 and uneven communication gaps caused by positioning deviations during the assembly of the upper shell 22 and the lower shell 23. This design can form a regular and continuous through hole 21 channel, ensuring that the directional airflow flows smoothly through the through holes 21 during the rotation of the cutter head, and the broken grass stems can also be stably discharged along the communication channel; at the same time, the extension wall 24 can also enhance the connection strength between the upper shell 22 and the lower shell 23, ensuring the integrity of the through hole 21 structure.

[0093] The extension wall 24 connects the upper shell 22 and the lower shell 23 through the inner wall of the through hole 21, eliminating the need for high-precision fitting between the inner wall of the non-through hole 21 area of ​​the upper shell 22 and the outer wall of the non-through hole 21 area of ​​the lower shell 23. The upper shell 22 can independently complete the machining of its outer wall and the first through hole 221, and the lower shell 23 can independently complete the machining of its inner wall and the second through hole 231, without needing to consider the fitting accuracy of the non-through hole 21 areas of the two shells. This reduces the fitting and calibration steps in the machining process and significantly lowers the machining difficulty.

[0094] Since the upper shell 22 and lower shell 23 do not need to be connected through surface-to-surface contact in the non-through-hole 21 area, the wall thickness or volume of the non-through-hole 21 area can be reduced accordingly, eliminating the need for redundant materials to meet adaptation requirements. Furthermore, the extension wall 24 is only positioned around the through-hole 21, providing structural support only at necessary points where the through-hole 21 connects, avoiding the additional material consumption required for an integral structure or large-area contact connection, effectively reducing the total material usage of the support part 20. Simultaneously, the connection method between the extension wall 24 and the inner wall of the through-hole 21 achieves lightweight design while simultaneously strengthening the structure around the through-hole 21 through the extension wall 24. This compensates for any potential decrease in strength of the support part 20 due to material reduction, ensuring sufficient structural stability during high-speed rotation and under cutting loads, meeting the strength requirements of the cutter head during long-term operation.

[0095] The lightweight design of the support section 20 reduces the overall weight of the cutter head, decreases inertial resistance during cutter head rotation, and consequently reduces the start-up and operating load of the lawnmower drive unit, optimizing the drive unit's efficiency and service life. The extension wall 24, along with the upper shell 22 and / or lower shell 23, adopts a one-piece molding design, eliminating gaps between components and stress concentration points during assembly, forming a continuous structural unit. Compared to a split assembly structure, the one-piece molded extension wall 24 can more stably withstand the centrifugal force, airflow impact force, and contact force during grass stem guidance during high-speed cutter head rotation. This effectively prevents cracking and deformation at the connection between the extension wall 24 and the inner wall of the through hole 21 due to uneven stress, further compensating for localized structural strength loss in the support section 20 caused by the through hole 21, ensuring the stability and durability of the overall structure of the support section 20 during long-term operation.

[0096] In some example embodiments of this application, based on the foregoing scheme, the extension wall 24 is integrally formed with the upper shell 22 and / or the lower shell 23.

[0097] In this type of embodiment, the integrally formed structure can eliminate the splicing gaps between components and the stress concentration points during assembly, so that the extension wall 24 and the upper shell 22 / lower shell 23 form a continuous structural whole, which can effectively avoid problems such as cracking and deformation at the connection between the extension wall 24 and the inner wall of the through hole 21 due to uneven stress.

[0098] The extension wall 24 is integrally molded with the upper shell 22 and / or lower shell 23, which eliminates the splicing gaps between components and the stress concentration points during assembly, making the extension wall 24 and the upper shell 22 / lower shell 23 form a continuous structural whole. Compared with the split assembly structure, the integrally molded extension wall 24 can more stably withstand the centrifugal force, airflow impact force and contact force during the high-speed rotation of the cutter head, and the flow of grass stems. It effectively avoids cracking and deformation problems at the connection between the extension wall 24 and the inner wall of the through hole 21 due to uneven stress, and further compensates for the local structural strength loss of the support part 20 caused by the opening of the through hole 21, ensuring the stability and durability of the overall structure of the support part 20 in long-term operation.

[0099] As a high-speed rotating component, the uniformity of the cutter head's mass distribution directly affects the lawnmower's operational stability. When the extension wall 24 is integrally formed with the upper shell 22 / lower shell 23, precision mold processing can ensure the dimensional accuracy, positional accuracy, and uniformity of material density of the extension wall 24, avoiding mass eccentricity of the extension wall 24 caused by part tolerances and assembly gaps during separate assembly. This design ensures that the overall center of mass of the cutter head is highly aligned with the output shaft axis of the drive unit, reducing centrifugal force offset during cutter head rotation. This reduces vibration and noise during lawnmower operation, avoids increased transmission losses in the drive unit and blade 40 cutting trajectory deviation caused by vibration, and extends the service life of drive units such as motors and couplings.

[0100] Please see Figure 3 In some example embodiments of this application, based on the aforementioned scheme, the cutter head assembly further includes an extension wall 24, which surrounds the edge of the second through hole 231. The extension wall 24 is integrally formed with the lower shell 23 and extends upward. The extended end of the extension wall 24 abuts against the upper shell 22. Alternatively, the extension wall 24 extends at least partially into the first through hole 221, and the outer wall of the extension wall 24 is adapted to the first through hole 221 so that the first through hole 221 communicates with the second through hole 231.

[0101] In this type of embodiment, the extension wall 24 is integrally formed with the lower shell 23 in both schemes, inheriting the advantages of the integrally formed structure with no splicing gaps and strong resistance to deformation, which can avoid the failure of the through hole 21 due to the fracture of the connection between the extension wall 24 and the lower shell 23 under stress.

[0102] Specifically, the extension wall 24 surrounds the edge of the second through hole 231 and is integrally formed with the lower shell 23. After extending upward, it directly abuts against the upper shell 22 to achieve communication between the first through hole 221 and the second through hole 231, eliminating the need for additional complex fitting structures such as snaps, threads, or seals. This design simplifies the path to achieve communication of the through hole 21 through a direct physical abutment, reducing the types of parts processed and assembly steps, lowering production and assembly costs, and quickly ensuring the conductivity of the through hole 21. This avoids hole blockage or airflow obstruction caused by improper fitting of complex structures, ensuring the stable realization of the basic function of expelling broken grass stems through the through hole 21.

[0103] The extension wall 24 extends at least partially into the first through hole 221, and its outer wall is adapted to the first through hole 221, forming an embedded connection structure. On the one hand, the adapted contact area between the extension wall 24 and the first through hole 221 is much larger than the contact area of ​​simple contact, which greatly improves the bonding between the upper shell 22 and the lower shell 23. This effectively resists the centrifugal force and vibration generated when the cutter head rotates at high speed, and prevents the through hole 21 from being misaligned due to relative displacement of the upper and lower shells 23, thus improving the overall structural stability of the support part 20. On the other hand, the adaptable extension design provides a precise positioning reference for the first through hole 221 and the second through hole 231, which can strictly control the coaxiality or hole alignment of the two holes, avoiding problems such as reduced airflow cross-sectional area and grass stem jamming caused by hole misalignment. This ensures that the directional airflow from top to bottom passes smoothly through the through hole 21, enhancing the effect of removing broken grass stems. At the same time, this structure can also reduce assembly errors, improve the consistency of different cutter head components, and facilitate mass production.

[0104] In one alternative, the extension wall 24 is integrally formed with the upper shell 22 and extends downward, with the extended end of the extension wall 24 abutting against the lower shell 23; or, the extension wall 24 extends at least partially into the second through hole 231, and the outer wall of the extension wall 24 is adapted to the second through hole 231.

[0105] Please see Figure 3 In some example embodiments of this application, based on the aforementioned scheme, the upper shell 22 is connected to the outer ring of the drive unit 10 and the inner ring of the mounting unit 30 respectively, and the lower shell 23 is detachably connected to the drive unit 10.

[0106] Please see Figure 6 In some example embodiments of this application, based on the aforementioned scheme, the upper shell 22 is connected to the outer ring of the driving part 10 and the inner ring of the mounting part 30 respectively, and the lower shell 23 is detachably connected to the mounting part 30.

[0107] In this type of embodiment, the upper shell 22 uses the outer ring of the drive unit 10 and the inner ring of the mounting unit 30 as dual assembly references. This allows for precise determination of its spatial position relative to the two core components, the drive unit 10 and the mounting unit 30, laying a unified positioning foundation for the subsequent assembly of the lower shell 23. When the lower shell 23 is detachably connected to the mounting unit 30 and / or the drive unit 10, the aforementioned drive unit 10 and mounting unit 30 can be used as assembly references, effectively avoiding positioning deviations caused by using different assembly references and ensuring the spatial matching degree between the lower shell 23 and the upper shell 22. Ultimately, this improves the overall assembly accuracy between the upper shell 22, the lower shell 23, the drive unit 10, and the mounting unit 30, providing assurance for the structural stability of the support unit 20, the reliability of the through hole 21, and the accuracy of airflow guidance.

[0108] In one specific embodiment, the mounting part 30 is provided with multiple mounting holes parallel to its axis, the blade 40 is provided with corresponding assembly holes, and the outer ring of the lower shell 23 is provided with assembly holes. The axes of the three holes are aligned, and fasteners pass through to fix the three together as one.

[0109] Please see Figure 3 In some example embodiments of this application, based on the aforementioned scheme, the cone angle α of the outer wall is between 72° and 84°, and the ratio i of the surface area of ​​the support 20 on the side away from the ground to the surface area of ​​the support 20 on the side close to the ground satisfies 0.5≤i<1.

[0110] In this type of embodiment, when the outer wall cone angle α is in the range of 72° to 84°, it balances the grass stem guidance with the structural space adaptability. Limiting the outer wall cone angle to the range of 72° to 84° can precisely avoid the technical defects caused by angle deviation: when α > 84°, the slope of the outer wall of the cone is insufficient, and the inclined surface tends to be gentle. After the grass stem contacts the outer wall, it is easy to stay on the wall surface or move towards the drive part 10 along the gentle surface, which cannot effectively play the role of tilting guidance and preventing approach; when α < 72°, the slope of the outer wall of the cone is too large, which will lead to a significant increase in the axial space occupied by the support part 20. This may not only cause layout interference with other components inside the lawnmower body, but also increase the overall height of the cutter head, affecting the lawnmower's passability in low lawns or complex terrain. The conical angle range of 72° to 84° ensures that the outer wall has sufficient slope, allowing the grass stems entering the solid area of ​​the support part 20 to slide quickly down the inclined wall, reducing the probability of them approaching the drive part 10. It also strictly controls the axial dimension of the support part 20, adapting to the compact internal structure layout of the lawnmower and avoiding spatial interference problems.

[0111] The surface area ratio i, 0.5≤i<1: This balances airflow guidance requirements with non-interference during movement. The ratio i of the surface area of ​​the support part 20 away from the ground to the surface area of ​​the support part 20, which is 0.5≤i<1, has a dual technical advantage: On the one hand, i<1 ensures that the surface area near the ground is greater than the surface area away from the ground, which meets the core requirement mentioned above that the lower surface area is larger to form an upward and downward pressure difference airflow. This can stably construct a directional airflow from top to bottom, providing a power basis for the discharge of broken grass stems through the through hole 21. On the other hand, the limitation of 0.5≤i can avoid excessive curvature of the inner wall of the support part 20. If i<0.5, the surface area near the ground is much larger than the surface area away from the ground, which will cause the inner wall to bulge excessively outward. The apex of its arc surface may exceed the horizontal plane of the outer ring of the outer wall, making it easy for the inner wall to collide and interfere with ground protrusions, lawn gravel, or roots when the cutter head moves, affecting the smoothness of the lawnmower's movement. The ratio range of 0.5≤i<1 can maintain the area difference required for pressure differential airflow and control the curvature of the inner wall within a reasonable range, ensuring that the inner wall does not exceed the horizontal plane of the outer ring of the outer wall. This structurally avoids unnecessary interference during the movement of the cutter head and ensures the continuity of the mowing operation.

[0112] Dual-parameter synergy: Enhancing the overall performance and stability of the cutter head assembly. The combination of the outer wall cone angle and the surface area ratio creates a synergistic effect: the reasonable setting of the cone angle strengthens the grass stem guidance and anti-close approach effect, while the optimization of the surface area ratio ensures airflow guidance efficiency and interference-free movement. Under the combined effect of the two, the risk of grass stem entanglement in the drive unit 10 can be reduced through the dual mechanism of inclined wall guidance and pressure difference airflow guidance. At the same time, it can avoid spatial interference or movement failure caused by unreasonable structural dimensions. Ultimately, it improves the structural adaptability, operational stability and long-term reliability of the cutter head assembly, adapting to the usage needs of intelligent lawn mowers in different lawn scenarios.

[0113] As a preferred embodiment, the cone angle α of the outer wall can be α=78°, which is a commonly used angle, corresponding to a slope of 15° on the outer wall, which facilitates positioning and processing.

[0114] Optionally, the cone angle α of the specific outer wall can be 72°, 72.5°, 73°, 73.5°, 74°, 74.5°, 75°, 75.5°, 76°, 76.5°, 77°, 77.5°, 78°, 78.5°, 79°, 79.5°, 80°, 80.5°, 81°, 81.5°, 82°, 82.5°, 83°, 83.5°, 84°, etc., but is not limited to these.

[0115] Based on the fact that the cone angle α of the outer wall is between 72° and 84°, the ratio i of the surface area of ​​the support 20 on the side away from the ground to the surface area of ​​the support 20 on the side closer to the ground can be 0.5, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.6, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, or 0.69. The values ​​are 0.7, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.8, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.9, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, etc., but are not limited to these.

[0116] In a preferred embodiment, the cone angle α of the outer wall can be α=78°, and the ratio i of the surface area of ​​the support 20 on the side away from the ground to the surface area of ​​the support 20 on the side close to the ground is 0.855.

[0117] In some example embodiments of this application, based on the aforementioned scheme, multiple through holes 21 are provided and arranged in an array around the axis of the support portion 20.

[0118] In this type of embodiment, multiple through holes 21 are arranged in an array around the axis of the support 20. Compared with a single through hole 21, this significantly increases the number of discharge paths for broken grass stems, and the array distribution can achieve full coverage of the grass discharge area in the circumferential direction of the support 20. When the cutter head rotates and generates a directional airflow from top to bottom, the broken grass stems entering above the cutter head, regardless of their position on the circumference of the support 20, can quickly find the corresponding through hole 21 for discharge.

[0119] This avoids grass stem retention caused by the limited drainage range of a single through-hole 21, such as localized grass stem accumulation in areas without through-holes 21. Simultaneously, the multiple through-holes 21 expand the total cross-sectional area of ​​the overall grass drainage channel, allowing more broken grass stems to pass through simultaneously, improving drainage efficiency per unit time, and further reducing the chance of grass stems contacting the drive unit 10 above the cutter head, thus ensuring that grass stems do not accumulate towards the drive unit 10 in terms of drainage capacity.

[0120] Multiple through holes 21 are symmetrically arranged along the axis of the support 20, ensuring a uniform mass distribution in the circumferential direction of the support 20 and preventing the center of gravity of the support 20 from shifting due to the misalignment or limited number of through holes 21. When the cutter head rotates at high speed, the uniform mass distribution can significantly reduce the centrifugal vibration of the support 20, reducing additional energy consumption and component wear caused by vibration, while ensuring a stable cutting trajectory of the cutter head, indirectly improving the operating accuracy and stability of the lawnmower. This provides a complementary solution to the problem of blade speed fluctuation caused by grass stem entanglement in the prior art.

[0121] When the multi-hole array 21 is arranged, uniformly spaced solid support segments are naturally formed between adjacent through holes 21. These solid segments can stably connect the inner and outer rings of the support part 20, forming a distributed support structure in the circumferential direction. This structure can effectively disperse the torque transmitted by the drive part 10 and the reaction force generated when the mounting part 30 is cut, avoiding a decrease in the overall structural strength of the support part 20 due to the opening of the through holes 21.

[0122] This design, which combines multiple through-holes 21 for grass drainage with solid support, not only enhances the grass stem drainage effect through the multiple through-holes 21, but also ensures the structural durability of the support part 20 through the evenly distributed solid sections. It achieves a balance between function and strength, avoids deformation or breakage of the support part 20 due to structural weakness, and extends the service life of the cutter head assembly.

[0123] In some alternative solutions, the through hole 21 can be a round hole, a strip hole, an arc hole, a square hole, or an irregularly shaped hole. For irregularly shaped holes, the inner wall must be kept smooth.

[0124] In some alternative designs, the diameter of the through hole 21 gradually increases in the direction of its extension from the outer wall to the inner wall. This design causes the opening to gradually decrease in the direction of its contraction from the inner wall to the outer wall, which can reduce the amount of grass stems or grass clippings falling through the through hole 21 and return them along the same path, thereby ensuring the function of removing clippings.

[0125] In some example embodiments of this application, based on the aforementioned scheme, a beam 25 is formed between adjacent through holes 21. On the horizontal projection plane, with the projection of the axis of the support 20 as the center, the maximum central angle β of any through hole 21 relative to the center of the circle is 75°≤β≤105°.

[0126] In this type of embodiment, the beams 25 formed between adjacent through holes 21 are distributed in an array. Combined with a central angle setting of 75°≤β≤105°, the number of beams 25 in the circumferential direction of the support part 20 can be stabilized at 3 to 4 (360° / 105°≈3.4, 360° / 75°=4.8, in actual processing there are 3 to 4 complete beams 25), forming a uniform distributed support structure. This structure can effectively connect the inner ring and outer ring of the support part 20, and evenly distribute the reaction force generated by the blade 40 when cutting grass stems to each beam 25, avoiding deformation or displacement of the mounting part 30 due to concentrated force, ensuring that the blade 40 always maintains a stable cutting trajectory, directly guaranteeing the grass cutting effect, and at the same time solving the problem of weak support caused by a single through hole 21 or non-array beams 25, improving the overall deformation resistance of the support part 20.

[0127] Setting β≥75° ensures that the opening angle of each through hole 21 on the horizontal projection plane is large enough, avoiding blockage or obstruction of broken grass stems due to excessively narrow openings in the through holes 21. This ensures that broken grass stems can be quickly discharged to the bottom of the cutter head through the through holes 21, reducing the risk of grass stems lingering and entanglement in the drive unit 10 from the perspective of the discharge channel size. Setting β≤105° avoids the number of beams 25 being less than 3 due to excessively large openings in the through holes 21 (if β>105°, the number of beams 25 will be less than 3). This prevents the support unit 20 from having single-point support or uneven stress due to insufficient number of beams 25. Three or more beams 25 can form a triangular stable support structure or multi-angle balanced support, ensuring the structural stability of the support unit 20 when the cutter head rotates at high speed and the blade 40 cuts. This avoids the beams 25 breaking or deforming due to overload, achieving a precise balance between a sufficiently large discharge channel and a sufficiently stable support structure.

[0128] The arrayed beams 25 and precisely controlled central angles ensure uniform mass and stress distribution along the circumference of the support 20, preventing center of gravity shift due to excessively wide / narrow beams 25 or uneven opening of through holes 21. When the cutter head rotates at high speed, the uniform mass distribution significantly reduces centrifugal vibration, decreasing wear at the connection points between the support 20 and the drive unit 10 and mounting unit 30. Simultaneously, the uniform stress distribution prevents a single beam 25 from bearing excessive loads for extended periods, extending its fatigue life and improving the overall durability of the cutter head assembly. This reduces maintenance frequency due to structural failures, indirectly lowering the operating costs of the lawnmower.

[0129] As a preferred embodiment, with the projection of the axis of the support portion 20 as the center, the maximum central angle β of any through hole 21 relative to the center can be β=96°.

[0130] Optionally, with the projection of the axis of the support 20 as the center, the maximum central angle β of any through hole 21 relative to the center can be 75°, 75.5°, 76°, 76.5°, 77°, 77.5°, 78°, 78.5°, 79°, 79.5°, 80°, 80.5°, 81°, 81.5°, 82°, 82.5°, 83°, 83.5°, 84°, 84.5°, 75°, 75.5°, 76°, 76.5°, 77°, 77.5°, 78°, 78.5°, 79°, 79.5°, 80°, 80.5°, 81°, 81.5°, 82°, 82.5°, 83°, 83.5°. The angles can be 84°, 84.5°, 85°, 85.5°, 86°, 86.5°, 87°, 87.5°, 88°, 88.5°, 89°, 89.5°, 90°, 90.5°, 91°, 91.5°, 92°, 92.5°, 93°, 93.5°, 94°, 94.5°, 95°, 95.5°, 96°, 96.5°, 97°, 97.5°, 98°, 98.5°, 99°, 99.5°, 100°, 100.5°, 101°, 101.5°, 102°, 102.5°, 103°, 103.5°, 104°, 104.5°, or 105°, but are not limited to these.

[0131] See Figure 1 and Figure 2 In some example embodiments of this application, based on the aforementioned scheme, multiple blades 40 are provided, and in the horizontal projection plane, the blades 40 at least partially overlap with the beam 25 in the radial direction of the support 20.

[0132] It is understandable that when the blade 40 cuts the grass stem, a radial load will be generated due to the reaction force of the grass stem. In the horizontal projection plane, the blade 40 and the beam 25 at least partially overlap in the radial direction of the support 20, allowing the radial load generated by cutting to be directly transmitted along the beam 25. The beam 25 is a solid support structure between adjacent through holes 21 and is itself the core load-bearing unit of the support 20, possessing stronger resistance to deformation and fracture. Compared to the misalignment of the radial position of the blade 40 with the beam 25, this design effectively avoids the concentration of load on the weak parts of the support 20, significantly reducing the risk of cracking and deformation of the support 20 due to excessive local stress, and ensuring the overall structural integrity of the cutter head.

[0133] Meanwhile, the inherent function of the beam 25 is to connect the inner and outer rings of the support 20 and to distribute the torque transmitted by the drive 10 and the radial force generated by cutting. The design of the blade 40 radially coinciding with the beam 25 allows the cutting force to be quickly transmitted through the beam 25 to the inner and outer rings of the support 20, and then further transmitted to the drive 10 and the machine body, forming a complete closed-loop force distribution system where the blade 40 bears the force, the beam 25 supports the load, and the force is distributed throughout the entire system. This closed loop effectively reduces the load on the non-load-bearing area of ​​the cutter head, avoids structural fatigue of the cutter head caused by local overload, significantly improves the wear resistance of the cutter head assembly, and extends the overall service life, making it particularly suitable for long-term operation scenarios on complex lawns containing coarse grass stems and a small amount of impurities.

[0134] Understandably, when the blade 40 is subjected to radial force, if the force cannot be effectively transmitted along the beam 25, it is prone to radial displacement, leading to uneven cutting depth and missed cuts. The design of the blade 40 radially coinciding with the beam 25, through the rigid support of the beam 25, restricts the radial displacement of the blade 40, ensuring that the blade 40 maintains its preset radial position throughout the cutting process, thus maintaining a stable cutting trajectory. Simultaneously, the evenly distributed multiple blades 40 allow for balanced transmission of the overall cutting load along the circumference, preventing vibration of the cutter head due to uneven force distribution, further improving cutting accuracy and optimizing mowing performance.

[0135] See Figure 1 and Figure 2 In a preferred embodiment of this application, the beam 25 is a symmetrical structure, the blade 40 is also a symmetrical structure, and the axis of symmetry of the assembled blade 40 is on the same plane as the axis of symmetry of the beam 25. Such a fit structure has the best strength and the best radial load-bearing capacity.

[0136] In some example embodiments of this application, based on the aforementioned scheme, the through holes 21 are all arc-shaped holes, and the outer ring and inner ring of the arc-shaped holes are both circularly transitioned with the beam body 25.

[0137] In this type of embodiment, firstly, the arc-shaped hole, compared with non-arc-shaped holes such as square or polygonal holes, can effectively disperse the centrifugal force and cutting reaction force borne by the support part 20 during the rotation of the cutter head, and avoid local stress concentration at the edge of the hole.

[0138] The arc-shaped structure itself has better mechanical load-bearing characteristics. While ensuring the grass discharge function of the through hole 21, it can enhance the overall structural stability of the support part 20. It can meet the strength requirements when the cutter head rotates at high speed without adding extra material thickness, and is suitable for the stress scenarios of long-term cutting operations of lawnmowers.

[0139] Both the outer and inner rings of the arc-shaped hole adopt a rounded transition design with the beam 25. On the one hand, this allows the material width at the connection between the beam 25 and the arc-shaped hole to be naturally widened. Compared with a right-angle transition, the rounded transition eliminates the problem of abrupt material reduction at sharp corners and increases the material bearing area at this critical connection position. On the other hand, the rounded transition can guide external forces to be evenly transmitted to the beam 25 along the arc surface, avoiding local deformation caused by force accumulation at the connection.

[0140] This design specifically addresses the potential problem of stress concentration damage at the connection between the through hole 21 and the beam 25, significantly improving the support stability of the beam 25 for the inner and outer rings of the support part 20, ensuring reliable cutting force transmission after the blade 40 is installed, and maintaining a stable mowing effect.

[0141] Furthermore, the circular arc transition structure, when applied to machining methods such as milling, can reduce the size requirements of the cutting tool and the requirements for the travel path, which is beneficial to manufacturing.

[0142] According to one aspect of this application, a cutting apparatus is provided, the cutting apparatus including a drive unit and a cutter head assembly as described above, the cutter head of the cutter head assembly being connected to the drive unit.

[0143] The cutting device consists of a drive unit and the aforementioned cutter head assembly. With its multi-hole 21 and airflow directional design, the cutter head assembly can effectively prevent broken grass stems from accumulating in the drive unit area and quickly discharge them. This significantly reduces the probability of the drive unit being entangled by grass stems, thereby maintaining the stable transmission efficiency of the drive unit and avoiding problems such as reduced speed and increased power consumption caused by grass stem entanglement. This ensures the overall operational stability of the cutting device and extends the service life of the drive unit and the entire device.

[0144] In the cutting device, the cutter head assembly is directly connected to the drive unit. The cutter head assembly features a multi-layered anti-grass stem design combining physical barrier, airflow guidance, and structural protection: the annular support 20 prevents grass stems from approaching the drive unit from the side; the conical outer wall reduces the adhesion and upward movement of grass stems in the solid area of ​​the support 20; and the multi-array through-holes 21, combined with differential pressure airflow, quickly expel broken grass stems that have entered above the cutter head. These designs, through the connection between the cutter head assembly and the drive unit, directly extend the protection range to the drive unit, reducing the probability of grass stems contacting the drive unit's transmission components from the source. This effectively avoids the problem of grass stems entangled in the drive unit as described in the prior art, achieving precise protection for the drive unit.

[0145] Because the drive unit is not easily entangled by grass stems, the problem of increased transmission resistance caused by grass stem entanglement in traditional structures can be avoided: on the one hand, the drive unit can always maintain a stable output speed, ensuring a constant cutting speed of the cutter head, without the phenomenon of reduced cutting efficiency or missed cuts caused by speed decay; on the other hand, the load of the drive unit will not exceed the threshold due to entanglement, which can avoid problems such as a surge in power consumption and motor overheating, extend the service life of the drive unit, and reduce the downtime of the cutting device caused by drive unit failure, ensuring the continuous and stable operation capability of the device.

[0146] The drive unit is less prone to tangling with grass stems, significantly reducing the frequency of manual disassembly and cleaning, thus lowering maintenance time and costs. It also prevents wear and tear on drive unit components caused by grass entanglement, reducing the need for replacing easily damaged parts. This effect allows the cutting device to maintain longer continuous operating time, making it particularly suitable for large-area lawn mowing scenarios, further enhancing the device's practicality and operational efficiency.

[0147] According to one aspect of this application, a lawnmower is provided, which includes a blade assembly as described above, or includes a cutting device as described above.

[0148] By incorporating the aforementioned blade assembly or cutting device, this lawnmower can effectively reduce the accumulation and entanglement of grass stems in the drive area during mowing operations by fully utilizing the multi-hole 21 chip removal and airflow directional design of the blade assembly, while ensuring the overall structural strength and rotational stability of the blade assembly. If equipped with a cutting device containing a drive unit, it can further utilize the protection mechanism of the blade assembly for the drive unit to prevent problems such as reduced speed, increased power consumption, or overheating caused by grass stem entanglement. Ultimately, this achieves stable cutting efficiency, extended component lifespan, and significantly improved operational reliability.

[0149] While this application has been described and illustrated in detail with reference to the accompanying drawings and the foregoing description, such description and illustration are intended to be illustrative or exemplary, not restrictive, and the application is not limited to the disclosed embodiments. Based on a study of the drawings, the disclosure, and the appended claims, those skilled in the art will understand and implement other embodiments and variations in carrying out the claimed invention. New embodiments can be obtained by combining any of the foregoing teachings.

[0150] The above embodiments are merely illustrative of the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A blade assembly for use in a lawnmower, characterized in that, include: The cutter head is provided with a driving part, an annular support part, and an annular mounting part arranged sequentially from the inside to the outside. The inner ring of the support part is connected to the driving part, and the inner ring of the mounting part is connected to the outer ring of the support part. The drive unit is used to connect to the drive unit of the lawnmower, and the outer ring of the mounting unit is equipped with a cutting blade. The support portion is provided with one or more through holes. When the cutter head rotates, the airflow velocity on the side of the support portion closer to the ground is less than the airflow velocity on the side of the support portion farther from the ground.

2. The cutter head assembly according to claim 1, characterized in that, The side of the support part away from the ground is the outer wall, which is conical in shape and gradually moves away from the ground in a direction close to its axis. The ratio of the surface area of ​​the support part away from the ground to the surface area of ​​the support part near the ground is i, where i < 1.

3. The cutter head assembly according to claim 2, characterized in that, The side of the support near the ground is the inner wall. In any section passing through the axis of the outer wall and not intersecting with the through hole, the projection of the outer wall is a straight line, and the projection of the inner wall is an arc, and the length of the arc is greater than the length of the straight line.

4. The cutter head assembly according to claim 3, characterized in that, The support includes a detachably connected upper shell and a lower shell. The side of the upper shell away from the lower shell is the outer wall, and the side of the lower shell away from the upper shell is the inner wall. The upper shell is provided with a first through hole, and the lower shell is provided with a second through hole. The first through hole and the second through hole communicate to form the through hole.

5. The cutter head assembly according to claim 4, characterized in that, It also includes an extension wall, which is vertically disposed between the upper shell and the lower shell; The two ends of the extension wall are respectively connected to the inner wall of the first through hole and the inner wall of the second through hole; or The extension wall is integrally formed with the lower shell and extends upward, with the extended end of the extension wall abutting against the upper shell; or, the extension wall at least partially extends into the first through hole, and the outer wall of the extension wall is adapted to the first through hole; or The extension wall is integrally formed with the upper shell and extends downward. The extension end of the extension wall abuts against the lower shell. Alternatively, the extension wall extends at least partially into the second through hole, and the outer wall of the extension wall is adapted to the second through hole.

6. The cutter head assembly according to claim 4, characterized in that, The upper shell is connected to the outer ring of the drive unit and the inner ring of the mounting unit, respectively, and the lower shell is detachably connected to the mounting unit and / or the drive unit.

7. The cutter head assembly according to claim 2, characterized in that, The cone angle α of the outer wall is between 72° and 84°, and the ratio i of the surface area of ​​the support part near the ground to the surface area of ​​the support part away from the ground satisfies 0.5≤i<1.

8. The cutter head assembly according to claim 1, characterized in that, The through holes are configured in multiple ways and arranged in an array around the axis of the support. A beam is formed between adjacent through holes. On the horizontal projection plane, with the projection of the axis of the support as the center, the maximum central angle β of any through hole relative to the center of the circle is 75°≤β≤105°.

9. The cutter head assembly according to claim 8, characterized in that, The blades are configured in multiple ways, and in the horizontal projection plane, the blades at least partially overlap with the beam in the radial direction of the support.

10. A lawnmower, characterized in that, The cutting device of the lawnmower includes a blade assembly as described in any one of claims 1 to 9.

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