Lawn mower

Abstract

The lawn mower comprises a cutting blade and a motor, the cutting blade comprises a blade base body and a hard material layer, and the blade base body comprises a first cutting edge and a second cutting edge and has first hardness; the hard material layer is compounded at the outer ends of the lower surfaces of the first cutting edge and the second cutting edge and has second hardness greater than the first hardness; the blade mounting structure comprises a mounting surface and a locking nut, the mounting surface is mounted on a power output shaft of the motor and rotates synchronously with the power output shaft, the locking nut is connected with the power output shaft of the motor in a threaded fit manner, and the cutting blade is pressed between the mounting surface and the locking nut; when the external impact force borne by the cutting blade is smaller than or equal to the friction force, the cutting blade synchronously rotates along with the power output shaft of the motor. When the external impact force borne by the cutting blade is larger than the friction force, the cutting blade can rotate relative to the power output shaft of the motor. The cutting blade does not need to be sharpened or replaced after being used for a long time, and the service life of the blade is long.

Description

Technical Field

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

[0002] Lawn mowers are widely used for trimming lawns and vegetation. Typically, a lawn mower consists of blades, a motor that drives the blades, and a battery pack that powers the motor. The rotation of the blades enables the mowing operation. During use, lawn mower blades gradually wear down and become dull, requiring frequent disassembly and sharpening of the blades before reuse. Otherwise, the cutting quality will be affected. This process repeats itself, requiring multiple sharpenings or blade replacements throughout the lawn mower's lifespan. Furthermore, the connection between the lawn mower blades and the motor's power output shaft usually uses a flat-square fit structure to transmit torque. This mounting structure, when the blades collide with hard objects during high-speed rotation, can cause high-intensity vibrations that can lead to the failure of the blade locking mechanism, resulting in the blades becoming loose, plastically deformed, or even tearing at the blade edge. Summary of the Invention

[0003] The purpose of this application is to provide a lawnmower in which the cutting blades remain sharp during use, are not easily deformed or torn, have a long blade life, and do not require sharpening or replacement during the lawnmower's lifespan.

[0004] The technical solution adopted in this application is as follows:

[0005] A lawnmower, comprising:

[0006] The cutting blade rotates around a fixed axis to perform the cutting operation; and

[0007] The motor is configured to drive the cutting blade to rotate, and includes a motor body and a power output shaft rotatably disposed on the motor body;

[0008] The cutting blade includes:

[0009] The blade base includes a rotating region, a first cutting region and a second cutting region opposite to each other on both sides of the rotating region, and a mounting hole provided in the rotating region for the power output shaft of the motor to pass through. The first cutting region has a first cutting edge, and the second cutting region has a second cutting edge. The blade base has a first hardness. The cutting blade is mounted on the power output shaft of the motor through the mounting hole.

[0010] A hard material layer is composited on the outer ends of the first and second cutting blades on the lower surface of the motor body, away from the motor body, along the axial direction of the motor's power output shaft; the hard material layer has a second hardness greater than the first hardness;

[0011] The lawnmower also includes a blade mounting structure, which includes:

[0012] Mounting surface, mounted on the power output shaft of the motor and rotating synchronously with the power output shaft of the motor; and

[0013] A locking nut is threadedly connected to the power output shaft of the motor to press the cutting blade between the mounting surface and the locking nut.

[0014] The lawnmower is configured such that when the power output shaft of the motor rotates, the cutting blade generates friction on the front and rear surfaces of the motor's power output shaft in the axial direction; when the external impact force on the cutting blade is less than the friction force, the cutting blade rotates synchronously with the motor's power output shaft; when the external impact force on the cutting blade is greater than the friction force, the cutting blade can rotate relative to the motor's power output shaft.

[0015] This application involves bonding a hard material layer to the cutting edge of the blade substrate, with the hardness of the hard material layer exceeding that of the blade substrate. During use, the softer blade substrate wears out faster, while the harder hard material layer wears out slower. After a period of use, the hard material layer protrudes, forming a sharp cutting edge. This edge remains sharp even with increased wear, eliminating the need for frequent sharpening. This reduces user workload and maintenance costs, while also providing high cutting quality, low energy consumption, ensuring even mowing and high-quality shredded grass, increasing single-pack usage time and working area, and extending blade life. Furthermore, this application utilizes friction to transmit torque. When the blade impacts a hard object during high-speed rotation, it rotates relative to the motor's power output shaft, preventing high-intensity vibrations caused by stalling that could lead to loosening of the locking nut, plastic deformation of the blade, or even blade tearing. This extends blade life and ensures the safety of the lawnmower, eliminating the need for sharpening or blade replacement throughout the lawnmower's lifespan.

[0016] In one embodiment, the blade mounting structure further includes a flange gasket, which is mounted on the power output shaft of the motor and positioned between the locking nut and the cutting blade; the locking nut is configured as a flange nut.

[0017] In one embodiment, the length of the cutting blade is 340–515 mm, and the length of the hard material layer is 40–100 mm.

[0018] And / or, the ratio of the length of the hard material layer to the length of the cutting blade is 7.8% to 29.4%.

[0019] In one embodiment, the width of the cutting blade is 32-60 mm, and the width of the hard material layer is 5-60 mm;

[0020] And / or, the ratio of the width of the hard material layer to the width of the cutting blade is 8.3% to 100%.

[0021] In one embodiment, the thickness of the cutting blade is 2-4 mm, and the thickness of the hard material layer is 0.1-0.8 mm;

[0022] And / or, the ratio of the thickness of the hard material layer to the thickness of the cutting blade is 2.5% to 40%.

[0023] In one embodiment, the hardness of the blade substrate is 40-48 HRC, and the hardness of the hard material layer is 60-65 HRC.

[0024] In one embodiment, the weight of the hard material layer is no more than 2g, and the dynamic balance of the cutting blade is no more than 160g.mm.

[0025] In one embodiment, the hard material layer is configured as a nickel-based composite alloy material coating.

[0026] In one embodiment, the lawnmower is configured as a push lawnmower, the motor speed is configured to be 2600-3800 rpm, and the linear speed of the cutting blade is configured to be 46.26-102.42 m / s.

[0027] In one embodiment, the motor includes a cooling fan, which is mounted on the motor's power output shaft via an insert. The motor can transmit torque to the cooling fan via the insert. The cooling fan and the insert are fixedly disposed relative to the motor's power output shaft and rotate synchronously with the motor's power output shaft. The surface of the cooling fan and / or the insert on the axial direction of the motor's power output shaft near the cutting blade forms the mounting surface. Attached Figure Description

[0028] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application.

[0029] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, they can obtain further information based on these drawings without creative effort.

[0030] Figure 1 This is a perspective view of a lawnmower in one embodiment of this application;

[0031] Figure 2 This is a bottom view of the cutting blade in one embodiment of this application;

[0032] Figure 3 This is a front view of a cutting blade in one embodiment of this application;

[0033] Figure 4 yes Figure 3 Enlarged view of point A in the middle;

[0034] Figure 5 This is a perspective view of the mounting structure of the cutting blade in one embodiment of this application;

[0035] Figure 6 This is a cross-sectional view of the mounting structure of the cutting blade in one embodiment of this application;

[0036] Figure 7 yes Figure 6 Enlarged view of point B in the middle. Detailed Implementation

[0037] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0038] Lawn mowers, as used in related technologies, are typically used for trimming lawns and vegetation. A lawn mower generally consists of blades, a motor that drives the blades to rotate, and a battery pack that powers the motor. The mowing operation is achieved by the rotation of the blades. For users, lawn mower maintenance includes regularly sharpening the blades and eventually replacing them several times during the mower's lifespan; both of these maintenance activities are costly. Furthermore, under harsh working conditions, the structural integrity of the lawn mower blades may be damaged, resulting in a shorter blade lifespan and unsafe operation. The main reasons are as follows:

[0039] On the one hand, during the mowing process, the blades of the lawnmower rub against grass, sand, etc., and the blade edges will gradually wear down, reducing their sharpness. The blades need to be disassembled and the edges sharpened before they can be used again. Otherwise, the dull edges will affect the flatness of the mowing, the quality of the shredded grass, the cutting quality will be poor, the energy consumption will increase, and the usage time and working area per bag will be reduced. This process repeats itself, requiring the blades to be sharpened multiple times during the life cycle of the lawnmower, which increases the workload of the user. Moreover, sharpening the blades usually requires the operation of professionals, and the blade life is short.

[0040] On the other hand, lawnmowers work in different environments and face different working conditions. In some harsh environments, because conventional technology usually uses a flat square mating structure to connect the lawnmower blades and the motor power output shaft to transmit torque and lock them with fasteners, this type of installation structure is prone to failure of the blade locking structure when the blade hits hard objects such as steel bars and stones during high-speed rotation due to the high intensity vibration generated by the stalled rotor. This can cause the blade to loosen, plastically deform, or even tear at the cutting edge.

[0041] Meanwhile, because the cutting blades need to be sharpened frequently, the frequency of disassembly and assembly increases. According to actual testing experience, users usually tighten the nuts manually without a dedicated torque display. Therefore, the force used to tighten the nuts is usually as high as 40 N.m, which is much greater than the normal assembly torque. This undoubtedly increases the risk of breakage and stripping of the motor shaft threads and nut threads.

[0042] It's understandable that users often hope that they won't need to sharpen or replace the blades during the lawnmower's lifespan. However, with conventional technology, blades may become unusable due to wear, plastic deformation, or blade cracking. It's difficult to guarantee that the blades will last long enough to meet the need for reliable operation throughout the lawnmower's entire lifespan under different working conditions.

[0043] To address the aforementioned problems, this application provides a lawnmower in which the cutting blades remain sharp throughout the entire lifespan of the lawnmower, eliminating the need for sharpening or replacement, and thus extending blade life. The structure of the lawnmower described below is illustrated using a push lawnmower as an example. This example is merely illustrative and does not limit the technical scope of this application.

[0044] Reference Figures 1 to 5The lawnmower 100 includes a cutting blade 10 and a motor 20. The cutting blade 10 rotates around a fixed axis P to perform cutting operations. The motor 20 is configured to drive the cutting blade 10 to rotate. The motor 20 includes a motor body 201 and a power output shaft 202 rotatably disposed on the motor body 201. The cutting blade 10 includes a blade base 101 and a hard material layer 102. The blade base 101 includes a rotating region 1011, a first cutting region 1012 and a second cutting region 1013 connected opposite to both sides of the rotating region 1011, and a mounting hole 1014 provided in the rotating region 1011 through which the power output shaft 202 of the motor 20 passes. The edge of the first cutting region 1012 is provided with a first cutting edge 1015, and the edge of the second cutting region 1013 is provided with a second cutting edge 1016. The blade base 101 has a first hardness. The cutting blade 10 is mounted on the power output shaft 202 of the motor 20 through the mounting hole 1014. The hard material layer 102 is composited at the outer end of the lower surface of the first cutting edge 1015 and the second cutting edge 1016 in the axial direction of the power output shaft 202 of the motor 20, away from the motor body 201; the hard material layer 102 has a second hardness greater than the first hardness.

[0045] Reference Figures 5 to 7 The lawnmower 100 also includes a blade mounting structure, which includes a mounting surface 30 and a locking nut 40. The mounting surface 30 is mounted on the power output shaft 202 of the motor 20 and rotates synchronously with the power output shaft 202 of the motor 20. The locking nut 40 is connected to the power output shaft 202 of the motor 20 via a threaded connection, pressing the cutting blade 10 between the mounting surface 30 and the locking nut 40. The lawnmower 100 is configured such that when the power output shaft 202 of the motor 20 rotates, the cutting blade 10 generates friction on the front and rear surfaces of the power output shaft 202 axially upward. When the external impact force on the cutting blade 10 is less than the friction force, the cutting blade 10 rotates synchronously with the power output shaft 202 of the motor 20. When the external impact force on the cutting blade 10 is greater than the friction force, the cutting blade 10 can rotate relative to the power output shaft 202 of the motor 20.

[0046] It should be understood that the cutting blade 10 is located between the mounting surface 30 and the locking nut 40. It should also be understood that the cutting blade 10 may be located between the mounting surface 30 and the locking nut 40 and be directly adjacent to the mounting surface 30 and the locking nut 40. Alternatively, the cutting blade 10 may be located between the mounting surface 30 and the locking nut 40, but other components may be included between the mounting surface 30 and the locking nut 40, and the cutting blade may not be directly adjacent to the mounting surface 30 or the locking nut 40.

[0047] This application incorporates a hard material layer 102 onto the cutting edge of the blade substrate 101, where the hard material layer 102 has a higher hardness than the blade substrate 101. During use, the blade substrate 101 is softer and wears faster, while the hard material layer 102 is harder and wears slower. After a period of use, the different wear rates of the two materials cause the hard material layer 102 to protrude, forming a sharp cutting edge. As wear increases, the cutting edge remains, ensuring the blade edge stays sharp, achieving a self-sharpening effect. This eliminates the need for frequent sharpening, reducing user workload and maintenance costs. Furthermore, it offers high cutting quality, low energy consumption, ensures smooth cutting and high-quality shredded grass, increases single-pack usage time and working area, and extends blade life. In addition, this application transmits torque through friction. When the blade hits a hard object during high-speed rotation, the cutting blade 10 can rotate relative to the power output shaft 202 of the motor 20. This avoids the high-intensity vibration caused by stalling, which could lead to the loosening of the locking nut 40, plastic deformation of the blade, or even tearing of the cutting edge. This can extend the blade's lifespan. During use, the blade will not fall off due to the loosening of the nut, ensuring the safety of the lawnmower and eliminating the need for sharpening or replacing the blade during the lawnmower's lifespan.

[0048] The first cutting edge 1015 and the second cutting edge 1016 form a gradually narrowing slope on the upper surface of the blade base 101. A hard material layer 102 is disposed on the lower surface of the blade base 101. It can be understood that disposing of the hard material layer 102 on the lower surface of the blade base 101 does not increase the windward area, effectively solving the problem of increased wind resistance caused by adding the hard material layer 102. Consequently, the operating current of the lawnmower will not increase, and the working capacity of the single battery pack will not be affected. Moreover, since the hardness of the hard material layer 102 is higher than that of the blade base 101, placing the hard material layer 102 on the lower surface of the blade base 101 can effectively prevent the hard material layer 102 from being damaged by external impacts first, ensuring the strength of the cutting blade 10.

[0049] Furthermore, the blade mounting structure also includes a flange gasket 50, which is mounted on the power output shaft 202 of the motor 20 and positioned between the locking nut 40 and the cutting blade 10; the locking nut 40 is configured as a flange nut.

[0050] The flange nut 40 includes a nut and a flange connected to the nut. The flange gasket 50 contacts and engages with the flange of the flange nut 40. The force generated by the rotation of the cutting blade 10 relative to the power output shaft 202 of the motor is transmitted to the locking nut 40, causing the locking nut 40 to tighten with each turn, thus ensuring that the locking nut 40 remains locked. This application adds a flange gasket 50 between the locking nut 40 and the cutting blade 10, and configures the locking nut 40 as a flange nut. When the cutting blade 10 rotates relative to the power output shaft 202 of the motor, the locking force transmitted to the locking nut 40 decreases, ensuring that the cutting blade 10 can continue to rotate under large impact forces, thereby protecting the cutting blade 10. In addition, when the cutting blade 10 is subjected to a large impact force and vibrates and deforms, adding a flange gasket 50 between the locking nut 40 and the cutting blade 10 can alleviate the vibration and deformation, prevent the locking nut 40 from loosening and causing the cutting blade 10 to fall off, and ensure that the locking nut 40 can always lock the cutting blade 10, thus ensuring the safety of the lawnmower.

[0051] Furthermore, the motor 20 includes a cooling fan 203, which is mounted on the power output shaft 202 of the motor 20 via an insert 204. The motor 20 can transmit torque to the cooling fan 203 via the insert 204. The cooling fan 203 and the insert 204 are fixedly arranged relative to the power output shaft 202 of the motor 20 and rotate synchronously with the power output shaft 202 of the motor 20. The cooling fan 203 and / or the insert 204 form the mounting surface 30 on the surface of the motor 20 near the cutting blade 10 in the axial direction of the power output shaft 202 of the motor 20.

[0052] The surface of the cooling fan 203 or insert 204 serving as the mounting surface 30 is configured to be approximately planar, so that the mounting surface 30 has a larger contact area with the cutting blade 10, generating greater friction. Preferably, the mounting surface 30 is formed on the surface of the insert 204.

[0053] In the lawnmower 100 of this application, when the locking nut 40 is tightened and the power output shaft 202 of the motor 20 rotates, frictional torque is generated between the cutting blade 10 and the flange gasket 50, and between the cutting blade 10 and the mounting surface 30. The frictional torque is a constant value. When the cutting blade 10 is subjected to a strong external impact force, the impact torque far exceeds the frictional torque. At this time, the cutting blade 10 will rotate relative to the power output shaft 202 of the motor 20 to cut off the torque transmission and protect the cutting blade 10.

[0054] In one embodiment, the length L1 of the cutting blade 10 is 340–515 mm, and the length L2 of the hard material layer 102 is 40–100 mm. Exemplarily, the length L1 of the cutting blade can be 340 mm, 400 mm, 410 mm, 460 mm, 515 mm, etc., and the length L2 of the hard material layer can be 40 mm, 50 mm, 65 mm, 80 mm, 100 mm, etc. Preferably, the length L1 of the cutting blade 10 is 400–515 mm, and the length L2 of the hard material layer 102 is 50–80 mm.

[0055] In one embodiment, the ratio of the length L2 of the hard material layer 102 to the length L1 of the cutting blade 10 is 7.8% to 29.4%. Exemplarily, the ratio of the length L2 of the hard material layer 102 to the length L1 of the cutting blade 10 can be 7.8%, 9.7%, 12%, 15%, 18%, 20%, 29.4%, etc. Preferably, the ratio of the length L2 of the hard material layer 102 to the length L1 of the cutting blade 10 is 9.7% to 20%.

[0056] The cutting edge of the cutting blade 10 (i.e., the first cutting edge 1015 and the second cutting edge 1016) includes a main working area, which is the area where the cutting blade 10 contacts the grass and performs mowing during the cutting process. Preferably, the length of the hard material layer 102 is greater than the length of the main working area of ​​the blade edge to ensure the lifespan of the entire cutting edge. As an example, the length of the main working area of ​​the cutting blade 10 is 40 mm, and the length of the hard material layer is 50 mm.

[0057] In one embodiment, the width W1 of the cutting blade 10 is 32-60 mm, and the width W2 of the hard material layer 102 is 5-60 mm. Exemplarily, the width W1 of the cutting blade 10 can be 32 mm, 40 mm, 50 mm, 60 mm, etc., and the width W2 of the hard material layer 102 can be 5 mm, 8 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, etc. Preferably, the width W1 of the cutting blade 10 is 40-55 mm, and the width W2 of the hard material layer 102 is...

[0058] In one embodiment, the ratio of the width W2 of the hard material layer 102 to the width W1 of the cutting blade 10 is 8.3% to 100%. Exemplarily, the ratio of the width W2 of the hard material layer 102 to the width W1 of the cutting blade 10 can be 8.3%, 15%, 20%, 30%, 50%, 75%, 85%, 100%, etc. Preferably, the ratio of the width W2 of the hard material layer 102 to the width W1 of the cutting blade 10 is 15% to 100%. More preferably, the ratio of the width W2 of the hard material layer 102 to the width W1 of the cutting blade 10 is configured to be 15% to 50%, ensuring the wear resistance of the cutting blade 10 while minimizing the width, thus ensuring that the strength of the blade substrate 101 is not affected during high-temperature processing.

[0059] In one embodiment, the thickness D1 of the cutting blade 10 is 2–4 mm, and the thickness D2 of the hard material layer 102 is 0.1–0.8 mm. Exemplarily, the thickness D1 of the cutting blade 10 can be 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, etc., and the thickness D2 of the hard material layer 102 can be 0.1 mm, 0.2 mm, 0.3 mm, 0.45 mm, 0.5 mm, 0.6 mm, etc. Preferably, the thickness D1 of the cutting blade 10 is 2.5–3.5 mm, and the thickness D2 of the hard material layer 102 is 0.1–0.6 mm.

[0060] In one embodiment, the ratio of the thickness D2 of the hard material layer 102 to the thickness D1 of the cutting blade 10 is 2.5% to 40%. Exemplarily, the ratio of the thickness D2 of the hard material layer 102 to the thickness D1 of the cutting blade 10 can be 2.5%, 2.86%, 5%, 10%, 12%, 15%, 20%, 24%, 30%, 40%, etc. Preferably, the ratio of the thickness D2 of the hard material layer 102 to the thickness D1 of the cutting blade 10 is 2.86% to 24%.

[0061] The hardness of the cutting tool substrate 101 is 40–48 HRC, and the hardness of the hard material layer 102 is 60–65 HRC. For example, the cutting tool substrate is made of 40Mn or 40MnB. The hard material layer is made of a nickel-based composite alloy.

[0062] In one embodiment, the hard material layer is configured as a nickel-based composite alloy coating formed on the outer end of the lower surface of the cutting blade edge using laser cladding technology. In other embodiments, the hard material layer can also be laminated onto the blade substrate by processes such as spraying, riveting, or welding.

[0063] The weight of the hard material layer 102 is no more than 2g, and the dynamic balance of the cutting blade 10 is no more than 160g.mm. For example, the weight of the hard material layer 102 can be 1g, 1.2g, 1.5g, 1.8g, 2g, etc.

[0064] The weight of the hard material layer 102 is no more than 2g, and the hard material layer 102 is located in the main working area of ​​the cutting blade 10, which is also the dynamic balance sensitive area. This ensures that the dynamic balance of the cutting blade 10 is no more than 160g.mm, which is beneficial to the cutting smoothness and reduces the vibration of the whole machine when mowing grass.

[0065] In some embodiments, the lawnmower is configured as a push lawnmower, with the motor speed configured to be 2600–3800 rpm and the cutting blade linear velocity configured to be 46.26–102.42 m / s. The cutting blade linear velocity refers to the linear velocity of the outer edge of the cutting edge. Preferably, the motor speed is configured to be 2800–3300 rpm and the cutting blade linear velocity is configured to be 58.61–88.94 m / s. Exemplarily, in one embodiment, the blade length is 515 mm, and the motor has at least two speed settings of 2800 r / min and 3000 r / min, corresponding to cutting blade linear velocities of 75.46 m / s and 80.85 m / s. In another embodiment, the blade length is 410 mm, and the motor has at least two speed settings of 2800 r / min and 3300 r / min, corresponding to cutting blade linear velocities of 60.08 m / s and 70.81 m / s.

[0066] Furthermore, the inventors discovered that the thickness of the hard material layer 102 is related to the linear velocity of the cutting blade 10. From a cutting quality perspective, the lower the linear velocity of the cutting blade 10, the higher the required sharpness, and the smaller the required thickness of the hard material layer 102. From a strength perspective, if the thickness is too small, the hard material layer 102 will break upon impact. Therefore, cutting blades 10 with different linear velocities should be matched with corresponding thicknesses of hard material layer 102. Through research and verification, the inventors determined the optimal relationship between the linear velocity of the cutting blade 10 and the thickness of the hard material layer 102: when the linear velocity of the cutting blade 10 is between 58.61 m / s and 88.94 m / s, the thickness of the hard material layer 102 is preferably between 0.1 mm and 0.6 mm. Cutting blades with this relationship can maintain sharpness while meeting the requirements for cutting quality and hard material layer strength during long-term use.

[0067] In one specific embodiment, the lawnmower 100 is configured as a push lawnmower, including a cutting blade 10 and a motor 20. The cutting blade 10 rotates about a fixed axis P to perform cutting operations; the motor 20 is configured to drive the cutting blade 10 to rotate, and the motor 20 includes a motor body 201 and a power output shaft 202 rotatably disposed on the motor body 201. The cutting blade 10 includes a blade base 101 and a hard material layer 102. The blade base 101 includes a rotating region 1011, a first cutting region 1012 and a second cutting region 1013 connected opposite to each other on both sides of the rotating region 1011, and a mounting hole 1014 provided in the rotating region 1011 through which the power output shaft 202 of the motor 20 passes. The first cutting region 1012 has a first cutting edge 1015 at its edge, and the second cutting region 1013 has a second cutting edge 1016 at its edge. The blade base 101 has a first hardness. The cutting blade 10 is mounted on the power output shaft 202 of the motor 20 through the mounting hole 1014. A hard material layer 102 is composite at the outer ends of the first cutting edge 1015 and the second cutting edge 1016 on the lower surface of the motor body 201 in the axial direction of the power output shaft 202 of the motor. The hard material layer 102 has a second hardness greater than the first hardness.

[0068] The lawnmower 100 also includes a blade mounting structure, which includes a mounting surface 30, a locking nut 40, and a flange gasket 50. The mounting surface 30 is mounted on the power output shaft 202 of the motor and rotates synchronously with the power output shaft 202. The locking nut 40 is threadedly connected to the power output shaft 202 of the motor, pressing the cutting blade 10 between the mounting surface 30 and the locking nut 40. The lawnmower is configured such that when the power output shaft 202 of the motor rotates, the cutting blade 10 generates friction on the front and rear surfaces of the power output shaft 202 in the axial direction. When the external impact force on the cutting blade 10 is less than the friction force, the cutting blade 10 rotates synchronously with the power output shaft 202 of the motor. When the external impact force on the cutting blade 10 is greater than the friction force, the cutting blade 10 can rotate relative to the power output shaft 202 of the motor. A flange gasket 50 is mounted on the power output shaft 202 of the motor and positioned between the locking nut 40 and the cutting blade 10; the cutting blade 10 is pressed between the mounting surface 30 and the flange gasket 50. The locking nut 40 is configured as a flange nut. The motor 20 includes a cooling fan 203, which is mounted on the power output shaft 202 of the motor via an insert 204. The motor 20 can transmit torque to the cooling fan 203 via the insert 204. The cooling fan 203 and the insert 204 are fixedly positioned relative to the power output shaft 202 of the motor and rotate synchronously with the power output shaft 202. The mounting surface 30 is formed on the surface of the insert 204 near the cutting blade 10 in the axial direction of the power output shaft 202 of the motor.

[0069] The blade substrate 101 has a hardness of 40–48 HRC, and the hard material layer 102 has a hardness of 60–65 HRC. The blade substrate is made of 40Mn or 40MnB. The hard material layer is made of a nickel-based composite alloy. The hard material layer is configured as a nickel-based composite alloy coating formed on the outer end of the lower surface of the cutting blade edge using laser cladding technology. The weight of the hard material layer 102 is no more than 2g, and the dynamic balance of the cutting blade 10 is no more than 160g·mm.

[0070] The cutting edge of the cutting blade 10 (i.e., the first cutting edge 1015 and the second cutting edge 1016) includes a main working area, which is the area where the cutting blade 10 contacts the grass and performs the cutting action during mowing. The length of the hard material layer 102 is greater than the length of the main working area of ​​the blade edge to ensure the lifespan of the entire cutting edge.

[0071] The length L1 of the cutting blade 10 is 400–515 mm, and the length L2 of the hard material layer 102 is 50–80 mm. The ratio of the length L2 of the hard material layer 102 to the length L1 of the cutting blade 10 is 9.7%–20%.

[0072] The width W1 of the cutting blade 10 is 40-55 mm, and the width W2 of the hard material layer 102 is 5-20 mm. The ratio of the width W2 of the hard material layer 102 to the width W1 of the cutting blade 10 is configured to be 15%-50%.

[0073] The thickness D1 of the cutting blade 10 is 2.5–3.5 mm, and the thickness D2 of the hard material layer 102 is 0.1–0.6 mm. The ratio of the thickness D2 of the hard material layer 102 to the thickness D1 of the cutting blade 10 is 2.86%–24%.

[0074] The motor speed is configured to be 2800–3300 rpm; the linear speed of the cutting blade is configured to be 58.61–88.94 m / s. The linear speed of the cutting blade refers to the linear speed of the outer edge of the cutting edge.

[0075] In one specific embodiment, the blade base 101 has a length of 515 mm, a width of 50 mm, and a thickness of 3 mm; the hard material layer 102 has a length of 50 mm, a width of 10 mm, and a thickness of 0.45 mm. The main working area of ​​the cutting edge of the cutting blade 10 has a length of 40 mm. The motor 20 includes two speed settings: 2800 r / min and 3000 r / min. Correspondingly, the linear velocities of the cutting blade 10 are 75.46 m / s and 80.85 m / s.

[0076] In another specific embodiment, the blade base 101 has a length of 410 mm, a width of 50 mm, and a thickness of 2.5 mm; the hard material layer 102 has a length of 50 mm, a width of 10 mm, and a thickness of 0.45 mm. The main working area of ​​the cutting edge of the cutting blade 10 has a length of 40 mm. The motor 20 includes two speed settings: 2800 r / min and 3300 r / min. Correspondingly, the linear speeds of the cutting blade are 60.08 m / s and 70.81 m / s.

[0077] During lawnmower use, there are typically two operating conditions: normal and abnormal. Normal operating conditions refer to the lawnmower cutting grass normally on the ground, allowing the blades to encounter loosely hard objects such as branches, small stones, and plastic. Normal operating conditions account for approximately 85% of the machine's lifespan. Abnormal operating conditions occur when the lawnmower is operating at high speed, and the blades encounter very rigid objects (such as steel bars or stone blocks), or when the lawnmower is riding on a curb with the blades spinning at high speed. Abnormal operating conditions account for approximately 15% of the machine's lifespan. Although abnormal operating conditions are less common, they can easily damage the lawnmower blades, rendering them unusable and affecting the lifespan of both the blades and the entire machine.

[0078] The following comparisons were made between cutting blades with a hard material layer on the blade substrate (using the blade mounting structure that transmits torque through friction, i.e., wear-resistant blade + friction torque transmission structure), cutting blades without a hard material layer on the blade substrate (using the conventional blade locking structure that transmits torque directly through the motor's power output shaft, i.e., ordinary blade + conventional blade locking structure), and cutting blades with a hard material layer on the blade substrate (using the conventional blade locking structure that transmits torque directly through the motor's power output shaft, i.e., wear-resistant blade + conventional blade locking structure). All three types of blades were installed on the same lawnmower under the same conditions. The results are shown in the table below.

[0079]

[0080] Table 1

[0081] According to the verification results, conventional cutting blades and their mounting structures require sharpening once every 20 hours of operation on average. Taking a 60-hour lifespan as an example, this means more than three sharpenings are needed throughout the entire lifespan. A single strong impact will cause the blade to become unusable due to plastic deformation. After a period of use, the nut will loosen. The cutting blade and its mounting structure of this embodiment can maintain sharpness for at least 80 hours without sharpening. Taking a 60-hour lifespan as an example, no sharpening or blade replacement is needed throughout the entire lifespan. The blade will only become unusable after at least four strong impacts. After a period of use, the nut can still reliably lock the blade in place. The cutting blade and its mounting structure of this embodiment are significantly superior to conventional technology.

[0082] The specific combination of adding a hard material layer to the bottom of the blade and the blade mounting structure that transmits torque through friction in this application can overcome the problem that a single improved structure cannot guarantee the life of the lawnmower blade. In addition, the hard material layer has high hardness but is also brittle. The blade mounting structure that transmits torque through friction can effectively protect the hard material layer from cracking due to large external impacts, extend the life of the cutting blade, and ensure that the cutting blade can be used effectively throughout the entire life cycle of the lawnmower without the need for sharpening or replacing the blade.

[0083] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0084] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

[0085] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0086] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0087] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., 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, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0088] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0089] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

Claims

1. A mower comprising: a cutting blade configured to rotate about a fixed axis to perform a cutting operation; and a motor configured to drive the cutting blade to rotate, the motor comprising a motor body and a power output shaft rotatably arranged on the motor body; characterized in that the cutting blade comprises: a blade base comprising a rotating region, first and second cutting regions oppositely connected to two sides of the rotating region, and a mounting hole arranged on the rotating region and configured to pass through the power output shaft of the motor, the first cutting region being provided with a first cutting edge at an edge thereof, and the second cutting region being provided with a second cutting edge at an edge thereof; the blade base has a first hardness; the cutting blade is assembled on the power output shaft of the motor through the mounting hole; and a hard material layer compounded on outer ends of the first and second cutting edges away from a lower surface of the motor body in an axial direction of the power output shaft of the motor; the hard material layer has a second hardness greater than the first hardness; the mower further comprises a blade mounting structure, the blade mounting structure comprising: a mounting surface mounted on the power output shaft of the motor and configured to rotate synchronously with the power output shaft of the motor; and a locking nut threadedly connected with the power output shaft of the motor and configured to press the cutting blade between the mounting surface and the locking nut; the mower is configured such that, when the power output shaft of the motor rotates, the cutting blade generates a friction force on front and rear surfaces thereof in the axial direction of the power output shaft of the motor; when an external impact force acting on the cutting blade is less than the friction force, the cutting blade rotates synchronously with the power output shaft of the motor; and when the external impact force acting on the cutting blade is greater than the friction force, the cutting blade can rotate relatively to the power output shaft of the motor. the blade mounting structure further comprises a flange gasket assembled on the power output shaft of the motor and arranged between the locking nut and the cutting blade; and the locking nut is configured as a flange nut.

2. The lawnmower as claimed in claim 1, characterized in that the cutting blade has a length of 340-515 mm, and the hard material layer has a length of 40-100 mm; 3. The lawnmower as claimed in claim 1, characterized in that and / or, a ratio of the length of the hard material layer to the length of the cutting blade is 7.8%-29.4%. the cutting blade has a width of 32-60 mm, and the hard material layer has a width of 5-60 mm; 4. The lawnmower as claimed in claim 1, characterized in that and / or, a ratio of the width of the hard material layer to the width of the cutting blade is 8.3%-100%. the cutting blade has a thickness of 2-4 mm, and the hard material layer has a thickness of 0.1-0.8 mm; 5. The lawnmower as claimed in claim 1, characterized in that, and / or, a ratio of the thickness of the hard material layer to the thickness of the cutting blade is 2.5%-40%. the blade base has a hardness of 40-48 HRC, and the hard material layer has a hardness of 60-65 HRC.

6. The lawnmower as claimed in claim 1, characterized in that, the hard material layer has a weight of not more than 2 g, and the cutting blade has a dynamic balance of not more than 160 g·mm.

7. The mower of claim 1, wherein, the hard material layer is configured as a coating of a nickel-based composite alloy material.

8. The mower of claim 1, wherein, ​ 9. The lawn mower of claim 1, wherein, The mower is configured as a hand-push mower, the rotating speed of the motor is configured as 2600-3800 rpm, and the linear speed of the cutting blade is configured as 46.26-102.42 m / s.

10. The lawn mower of claim 1, wherein, The motor comprises a heat dissipation fan, the heat dissipation fan is assembled on the power output shaft of the motor through an insert, and the motor can transmit torque to the heat dissipation fan through the insert; the heat dissipation fan is fixedly arranged relative to the power output shaft of the motor and rotates synchronously with the power output shaft of the motor; and the surface of the heat dissipation fan and / or the insert close to the cutting blade in the axial direction of the power output shaft of the motor forms the mounting surface.

Images