Lawn mower

Abstract

The present invention discloses a lawn mower comprising: a blade assembly for performing a cutting function; a chassis having a space for accommodating at least a portion of the blade assembly; a motor for driving the blade assembly to rotate about a rotation axis; and a battery pack for providing power to the motor. The blade assembly comprises: a first blade having a first cutting edge for mowing; a second blade having a second cutting edge for mowing; the battery pack comprises: a battery pack housing; and a battery cell disposed within the battery pack housing. The maximum length of a line connecting any two points of the blade assembly's projection on a plane perpendicular to the rotation axis and the projection of the rotation axis on the same plane is the rotational diameter of the blade assembly. The present invention can provide a lawn mower with reduced motor load and higher cutting efficiency.

Description

Technical Field

[0001] The present invention relates to an electric machine, in particular to a lawn mower. Background Art

[0002] Mowing, a fundamental task in lawn maintenance, requires the use of simple and efficient mowing machinery to ensure both quality and quantity. Lawn mowers are now widely used in all types of lawns. The blade, as a functional component, significantly impacts the mower's cutting performance through its structural design.

[0003] Based on their energy source, lawn mowers can be categorized as either engine-driven or motor-driven. Motor-driven mowers typically use battery packs, offering advantages such as quieter operation and cleaner operation. However, current motor-driven mowers suffer from inefficient blade configurations, which can lead to high motor loads and low cutting efficiency. Summary of the Invention

[0004] In order to solve the deficiencies of the prior art, an object of the present invention is to provide a lawn mower with smaller motor load and higher cutting efficiency.

[0005] In order to achieve the above objectives, the present invention adopts the following technical solutions:

[0006] A lawn mower, comprising: a blade assembly for performing a cutting function; a chassis, formed with a storage space for accommodating at least part of the blade assembly; the lawn mower also comprises: a motor for driving the blade assembly to rotate about a rotation axis; a battery pack for providing a power source for the motor; wherein the blade assembly comprises: a first blade for mowing grass; a second blade for mowing grass; the second cutting portion is located below the first cutting portion in a direction parallel to the rotation axis; the battery pack comprises: a battery pack housing; a battery cell unit arranged in the battery pack housing; the maximum value of the length of the line connecting any two points of the projection of the blade assembly in a plane perpendicular to the rotation axis and the projection of the rotation axis in the plane is the rotation diameter of the blade assembly; wherein the product of the rotation diameter D of the blade assembly, the number N of battery cells contained in the battery pack and the weight M of the blade assembly is greater than or equal to 3.5×10 5 mm•pieces•grams and less than or equal to 7.3×10 7 Millimeters. Pieces. Grams.

[0007] Furthermore, the product of the rotation diameter D of the blade assembly, the number N of the battery cells, and the weight M of the blade assembly is greater than or equal to 7×10 5 mm•pieces•grams and less than or equal to 3.6×10 7 Millimeters. Pieces. Grams.

[0008] Furthermore, the product of the rotation diameter D of the blade assembly, the number N of the battery cells, and the weight M of the blade assembly is greater than or equal to 1.4×10 6 mm•pieces•grams and less than or equal to 1.8×10 7 Millimeters. Pieces. Grams.

[0009] Furthermore, the blade assembly includes: a first blade, formed with a first cutting portion; a second blade, formed with a second cutting portion; the first blade and the second blade are integrally formed or separately formed.

[0010] Furthermore, the output torque of the motor is greater than or equal to 0 and less than or equal to 10 Nm.

[0011] Furthermore, the output torque of the motor is greater than or equal to 3 Nm and less than or equal to 8 Nm.

[0012] Furthermore, the lawn mower further comprises a fan; the fan is fixedly connected to the output shaft of the motor and rotates about the rotation axis; the fan is mounted above the blade assembly and abuts against the blade assembly.

[0013] Furthermore, when the tip linear velocity of the blade assembly is greater than or equal to 40 m / s and less than or equal to 100 m / s, the average wind speed at the grass outlet is greater than or equal to 3 m / s and less than or equal to 25 m / s.

[0014] Furthermore, the lawn mower also includes a control system for controlling the operation of the motor. When the lawn mower is idling, the sum of the input power of the motor, the input power of the control system, and the input power of the blade assembly is the control input power of the lawn mower; the idling input power is greater than or equal to 100W and less than or equal to 380W.

[0015] Furthermore, the moment of inertia of the blade assembly is greater than or equal to 8000 kg·mm² and less than or equal to 23000 kg·mm².

[0016] The benefits of the present invention are as follows: the lawn mower of the present invention uses a motor to drive a blade assembly including double blades or a single blade. Since the structure, drive structure and mounting structure of the blade assembly are more optimized, the motor load of the lawn mower is smaller, the cutting efficiency is higher, the battery life is longer, the mounting structure of the blade assembly is better adapted, the blade assembly is more convenient to assemble and disassemble, and the cutting efficiency of the blade itself is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of a lawn mower according to a first embodiment of the present invention;

[0018] Figure 2 yes Figure 1 A plan view of a partial structure of a lawn mower;

[0019] Figure 3 yes Figure 1 A perspective view of a partial structure of a lawn mower;

[0020] Figure 4 yes Figure 1 A plan view of a portion of a blade assembly of a lawn mower;

[0021] Figure 5 yes Figure 1 A cross-sectional view of a portion of the structure of the lawn mower, wherein the mounting assembly is in a first mounting state;

[0022] Figure 6 yes Figure 1 Exploded view of part of the lawn mower structure;

[0023] Figure 7 is a schematic diagram of a partial structure of a lawn mower according to a first embodiment of the present invention, wherein the mounting assembly is in a second mounting state;

[0024] Figure 8 is a schematic diagram of a partial structure of a lawn mower according to a first embodiment of the present invention, wherein the mounting assembly is in a second mounting state;

[0025] Figure 9 yes Figure 1 An exploded view of the blade assembly of a lawn mower;

[0026] Figure 10 yes Figure 1 A schematic diagram of a first blade and a second blade of a lawn mower;

[0027] Figure 11 is a schematic diagram of a partial structure of a lawn mower according to a second embodiment of the present invention;

[0028] Figure 12 is a schematic diagram of a blade assembly and a connecting assembly of a lawn mower according to a third embodiment of the present invention;

[0029] Figure 13 is a schematic diagram of a blade assembly of a lawn mower according to a fourth embodiment of the present invention;

[0030] Figure 14 yes Figure 13 a plan view of the blade assembly in FIG.

[0031] Figure 15 yes Figure 13 a plan view of the second blade of the blade assembly;

[0032] Figure 16 yes Figure 13 A plan view of the second blade of the blade assembly from another perspective;

[0033] Figure 17 is a schematic diagram of a partial structure of a lawn mower according to a fifth embodiment of the present invention;

[0034] Figure 18 yes Figure 17 A cross-sectional view of the structure in FIG.

[0035] Figure 19 yes Figure 17 Exploded view of part of the lawn mower structure;

[0036] Figure 20 is a schematic diagram of a partial structure of a lawn mower according to a sixth embodiment of the present invention;

[0037] Figure 21 is a plan view of a blade assembly and a mounting assembly of a lawn mower according to a sixth embodiment of the present invention;

[0038] Figure 22 yes Figure 20 Exploded view of part of the lawn mower structure;

[0039] Figure 23 is a schematic diagram of a partial structure of a lawn mower according to a seventh embodiment of the present invention;

[0040] Figure 24 yes Figure 23 A cross-sectional view of the structure in FIG.

[0041] Figure 25 yes Figure 23 Exploded diagram of the structure in;

[0042] Figure 26 FIG. 1 is a schematic diagram of a partial structure of a lawn mower according to an eighth embodiment of the present invention. DETAILED DESCRIPTION

[0043] Figure 1 This is a schematic diagram of a lawn mower 100 according to the first embodiment of the present invention. Depending on the user's operation method, the lawn mower 100 of the present invention can be either a push lawn mower or a riding lawn mower. This embodiment is described using a motor-driven push lawn mower as an example. All "assemblies" in the present invention refer to a combination of at least one component, which realizes a specific function through interaction or coordination. To facilitate the description of the technical solution of the present invention, it is assumed as follows Figure 1 Up and down directions shown.

[0044] like Figures 1 to 3As shown, the lawn mower 100 includes a blade assembly 11, a chassis 12, a motor 13, and a battery pack. The blade assembly 11 is used to perform the cutting function of the lawn mower 100. The chassis 12 defines a housing for at least a portion of the blade assembly 11. In this embodiment, the blade assembly 11 is entirely located within the housing. The motor 13 drives the blade assembly 11 to rotate about a rotation axis 101. The motor 13 is located above the chassis 12 and rotates coaxially with the blade assembly 11 about the rotation axis 101. Specifically, the motor 13 includes a motor shaft. The lawn mower 100 also includes a drive shaft 14 that drives the blade assembly 11. The drive shaft 14 can be a motor shaft. However, a transmission mechanism can also be provided between the motor 13 and the blade assembly 11 to provide transmission, thereby enabling non-coaxial rotation of the motor 13 and the drive shaft 14. The battery pack provides power to the motor 13. The lawn mower 100 also includes a fan 15 connected to the drive shaft 14. The fan 15 rotates about an axis parallel to or coincident with the rotation axis 101.

[0045] When the motor 13 is started to drive the blade assembly 11 to rotate about the rotation axis 101, and when the motor 13 drives the blade assembly 11 to rotate about the rotation axis 101 and the linear velocity of the blade tip of the blade assembly 11 is greater than or equal to 40 m / s and less than or equal to 100 m / s, the operating time of the lawn mower 100 when the battery pack consumes 100WH of energy is defined as the 100Wh battery life of the lawn mower 100. The 100Wh battery life of the lawn mower 100 is greater than or equal to 4 minutes and less than or equal to 30 minutes; further, the 100Wh battery life of the lawn mower 100 is greater than or equal to 5 minutes and less than or equal to 20 minutes; and further, the 100Wh battery life of the lawn mower 100 is greater than or equal to 6 minutes and less than or equal to 15 minutes. In this embodiment, the 100Wh battery life of the lawn mower 100 is approximately 12 minutes. Because the lawn mower 100 of the present invention features a blade assembly 101 with a superior structural design, reduced load, and improved cutting efficiency, the lawn mower 100 maintains a 100Wh battery life within the aforementioned range during operation, resulting in superior cutting performance. It should be noted that the blade tip linear velocity refers to the linear velocity of the point on the blade assembly 11 that is farthest from the rotation axis 101. Furthermore, the battery pack referred to herein refers solely to the battery pack that provides power to the motor 13 that drives the blade assembly 11.

[0046] In addition, when the motor 13 drives the blade assembly 11 to rotate idly around the rotation axis 101, the operating time of the lawn mower 100 when the battery pack consumes 100WH of energy is defined as the no-load endurance time of the lawn mower 100. The no-load endurance time of the lawn mower 100 is greater than or equal to 9 minutes and less than or equal to 35 minutes; further, the 100Wh endurance time of the lawn mower 100 is greater than or equal to 12 minutes and less than or equal to 33 minutes; further, the 100Wh endurance time of the lawn mower 100 is greater than or equal to 18 minutes and less than or equal to 30 minutes. In this embodiment, the 100Wh endurance time of the lawn mower 100 is approximately 22 minutes. Because the lawn mower 100 of the present invention has a blade assembly 100 with a better structural design, a smaller load, and higher cutting efficiency, as well as a reasonable no-load condition setting, the lawn mower 100 has a 100Wh endurance time within the above range when in operation, thereby improving the working performance of the lawn mower 100.

[0047] like Figures 2 to 5 As shown, the blade assembly 11 includes a first blade 111 and a second blade 112, and the first blade 111 and the second blade 112 are respectively formed with a first cutting portion 111a and a second cutting portion 112a for mowing. When the first blade 111 and the second blade 112 are rotated as a whole around the rotation axis 101, the first cutting portion 111a and the second cutting portion 112a cut the grass. It should be noted that the cutting portion refers to a structure with a cutting function for cutting vegetation, which can be a common blade or a cutting structure different from a blade. A cutting portion refers to an integrally formed or continuous structure.

[0048] In the direction parallel to the rotation axis 101, the second cutting portion 112a is located below the first cutting portion 111a but is not limited to being directly below; or the second cutting portion 112a and the first cutting portion 111a are at least partially located in the same plane. In this embodiment, the first blade 111 and the second blade 112 are two separately formed blades, and the first blade 111 is located above the second blade 112 relative to the ground in the direction parallel to the rotation axis 101. The first blade 111 and the second blade 112 constitute synchronous rotation, specifically, as shown in FIG. Figure 2 As shown by the middle arrow, the first blade 111 and the second blade 112 rotate synchronously coaxially around the rotation direction A with the rotation axis 101 as the axis.

[0049] The lawn mower 100 also includes a control system for controlling the operation of the motor 13. When the lawn mower 100 is idling, the sum of the input power of the motor 13, the input power of the control system, and the input power of the blade assembly 11 is the control input power of the lawn mower 100. The idling input power is greater than or equal to 100 W and less than or equal to 380 W. Furthermore, the idling input power is greater than or equal to 200 W and less than or equal to 300 W.

[0050] It should be noted that no-load refers to the condition where the blade assembly 11 of the lawn mower 100 rotates at a preset speed under atmospheric pressure and there is no external load applied to the blade assembly 11 .

[0051] The volume of a minimum cylinder 11' that encloses the first blade 111 and the second blade 112 is defined as the swept volume of the blade assembly 11. When the blade assembly 11 rotates around the rotation axis 101, the first cutting portion 111a and the second cutting portion 112a are both located in the space surrounded by the minimum cylinder 11'. Figure 2 As shown, the dotted rectangle is a plan view of the cylinder 11' that encloses the first blade 111 and the second blade 112 in this embodiment. The swept volume of the blade assembly 11 is the volume of the cylinder 11'. Specifically, the volume of the cylinder 11' is approximately the volume of the cylinder 11' having a diameter equal to the rotational diameter D of the blade assembly 11 and a height equal to the maximum height of the blade assembly 11 in a direction parallel to or coinciding with the rotational axis 101. The rotational diameter D of the blade assembly 11 is the maximum length of the line connecting any two points of the projection of the blade assembly 11 in a plane perpendicular to the rotational axis 101 and the projection of the rotational axis 101 in the plane. In this embodiment, since the first blade 111 and the second blade 112 are both perpendicular to the rotation axis 101 and the first blade 111 and the second blade 112 are coaxially mounted to the drive shaft 14, the first blade 111 is located directly above the second blade 112. The swept volume of the blade assembly 11 is approximately the volume of a cylinder 11' having a radius equal to the maximum distance from any point on the blade assembly 11 to the rotation axis 101 and a height equal to the maximum sum of the heights of the first blade 111 and the second blade 112 in a direction parallel to the rotation axis 101. It should be noted that the heights of the first blade 111 and the second blade 112 are the maximum dimensions of the first blade 111 and the second blade 112 in a direction parallel to the rotation axis 101 when the blade assembly 11 is mounted to the drive shaft 14.

[0052] In the present invention, the swept volume of the blade assembly 11 is greater than or equal to 400 cm³ and less than or equal to 8000 cm³. When the swept volume of the blade assembly 11 remains within this range, the lawn mower 100 experiences a smaller load. In other words, when the swept volume of the blade assembly 11 remains within this range, the lawn mower 100 experiences a smaller load. At the same time, the dual blades ensure the cutting performance of the lawn mower 100, thereby enabling the lawn mower 100 to have higher cutting efficiency. Preferably, the swept volume of the blade assembly 11 is greater than or equal to 600 cm³ and less than or equal to 6800 cm³. Furthermore, the swept volume of the blade assembly 11 is greater than or equal to 1000 cm³ and less than or equal to 5000 cm³.

[0053] The structure of the blade assembly is not limited to that of this embodiment. As an alternative embodiment, the blade assembly includes only one blade; the first cutting portion and the second cutting portion are both disposed on the blade, with the second cutting portion located below, but not limited to, directly below, the first cutting portion in the direction of the rotation axis; the first cutting portion and the second cutting portion can be integrally formed or connected to other structures to form a complete blade. For example, the blade assembly includes a blade body, the first cutting portion and the second cutting portion are respectively disposed on a plurality of fins extending from the blade body, and the plurality of fins are fixedly connected to the blade body, integrally formed, or detachably connected.

[0054] like Figure 4 As shown, the phase angle α formed by the first cutting portion 111a and the second cutting portion 112a is greater than or equal to 0 degrees and less than 90 degrees. The phase angle α is the angle between the straight lines on which the projections of the blade edges 111b of the first cutting portion and the blade edges 112b of the second cutting portion are located in a plane perpendicular to the rotation axis 101. The blade edge 111b of the first cutting portion is the frontmost edge of the first cutting portion 111a, that is, the edge that first contacts the vegetation when the first blade 111 rotates along the cutting direction A with the rotation axis 101 as the axis; similarly, the blade edge 112b of the second cutting portion is the frontmost edge of the second cutting portion 112a, that is, the edge that first contacts the vegetation when the second blade 112 rotates along the cutting direction A with the rotation axis 101 as the axis. When the phase angle between the first cutting portion 111a and the second cutting portion 112a is within the above range, the cutting portion assembly as a whole has higher cutting efficiency. Furthermore, the phase angle α formed by the first cutting portion 111a and the second cutting portion 112a is greater than or equal to 10 degrees and less than or equal to 60 degrees. Specifically, in this embodiment, the phase angle α formed by the first cutting portion 111a and the second cutting portion 112a is approximately 20 degrees.

[0055] The first blade 111 includes at least one first cutting portion 111a, and the first cutting portion 111a can be considered as a continuous cutting portion formed on the first blade 111. Preferably, the first blade 111 and the second blade 112 include at least two first cutting portions 111a and a second cutting portion 112a, respectively. In this embodiment, two first cutting portions 111a are formed on the first blade 111, and the two first cutting portions 111a are respectively arranged at both ends of the first blade 111, and are both arranged on the front side of the cutting direction A, that is, when the first blade 111 rotates along the cutting direction A with the rotation axis 101 as the axis, the side that first contacts the vegetation; the two first cutting portions 111a are centrally symmetrical about the rotation axis 101. Similarly, the second blade 112 also includes at least one second cutting portion 112a. In this embodiment, two second cutting portions 112a are formed on the second blade 112. The two second cutting portions 112a are respectively arranged at both ends of the second blade 112, and are both arranged on the front side of the cutting direction A, that is, when the second blade 112 rotates along the cutting direction A with the rotation axis 101 as the axis, the side that first contacts the vegetation; the two second cutting portions 112a are centrally symmetrical about the rotation axis 101.

[0056] The sum of the number of first cutting portions 111a formed by the first blade 111 and the number of second cutting portions 112a formed by the second blade 112 (in units) is defined as the number of cutting portions of the blade assembly 11. For the blade assembly 11 of the present invention, the ratio of the swept volume of the blade assembly 11 to the number of cutting portions is greater than or equal to 75 cm³ / piece and less than or equal to 3400 cm³ / piece. Furthermore, the ratio of the swept volume of the blade assembly 11 to the number of cutting portions is greater than or equal to 150 cm³ / piece and less than or equal to 1700 cm³ / piece. It should be noted that the discontinuous first cutting portion 111a is considered to be a plurality of different first cutting portions 111a, with the number of first cutting portions 111a being the number of mutually discontinuous first cutting portions 111a provided on the first blade 111. Similarly, the discontinuous second cutting portion 112a is considered to be a plurality of different second cutting portions 112a, with the number of second cutting portions 112a being the number of mutually discontinuous second cutting portions 112a provided on the second blade 112. In this embodiment, the ratio of the swept volume of the blade assembly 11 to the number of cutting portions is approximately 1700 cm³ per blade assembly. Generally speaking, the greater the number of cutting portions, the better the cutting performance of the lawn mower 100. However, the greater the number of cutting portions, the greater the swept volume required of the blade assembly 11, and the correspondingly greater load on the lawn mower 100. In the present invention, by optimizing the structure of the blade assembly 11, the ratio of the swept volume of the blade assembly 11 to the number of cutting portions remains within the aforementioned preferred range, thereby ensuring that the lawn mower 100 maintains optimal cutting performance even under light loads.

[0057] The lawn mower 100 further includes a mounting assembly 16, which has a first mounting state in which the blade assembly 11 is mounted to the drive shaft 14 so that the blade assembly 11 rotates along with the drive shaft 14, and a second mounting state in which one of the first blade 111 and the second blade 112 is removed and only the other of the first cutting portion 111a and the second cutting portion 112a is mounted to perform a cutting function.

[0058] In this embodiment, Figures 5 to 8 As shown, because the first cutting portion 111a and the second cutting portion 112a are respectively provided on the separately formed first blade 111 and the second blade 112, the mounting assembly 16 has a first mounting state in which the blade assembly 11 is mounted to the drive shaft 14 so that the blade assembly 11 rotates with the drive shaft 14, and a second mounting state in which one of the first blade 111 and the second blade 112 is removed and only the other of the first blade 111 and the second blade 112 is mounted to perform the cutting function. In other words, the mounting assembly 16 can mount the blade assembly 11 comprising the first blade 111 and the second blade 112 to the drive shaft 14 in the first mounting state, and can also mount the blade assembly 11 comprising only one of the first blade 111 and the second blade 112 to the drive shaft 14 in the second mounting state. Considering the diversity of operating conditions, the mounting assembly 16 of the present invention has multiple mounting states, providing greater adaptability. This allows users to reduce or increase the number of blades according to their specific needs without having to completely replace the mounting assembly 16 and the blade assembly 11, thereby enhancing the practicality of mowing.

[0059] As an optional embodiment, the mounting assembly has a first mounting state for mounting a first type blade assembly including a first cutting portion and a second cutting portion to a drive shaft, and the mounting assembly further has a second mounting state for mounting a second type blade assembly including only a single cutting portion to the drive shaft when the first type blade assembly is disassembled. Based on the structure in which the first cutting portion and the second cutting portion are respectively provided on the first blade and the second blade, that is to say, the mounting assembly has a first mounting state for mounting the first type blade assembly including a first blade and a second blade to a drive shaft, and the mounting assembly further has a second mounting state for mounting the second type blade assembly including only a single blade to the drive shaft when the first type blade assembly is disassembled. In other words, the mounting assembly can independently mount not only one or both of the first blade and the second blade, but also another blade that does not belong to the first blade or the second blade.

[0060] As another alternative embodiment, a lawn mower includes a first-type blade assembly for performing a cutting function, the first-type blade assembly including a first blade having a first cutting portion for mowing. A mounting assembly has a first mounting position in which the first-type blade assembly is mounted to a drive shaft so that the blade assembly rotates with the drive shaft. The mounting assembly also has a second mounting position in which the first-type blade assembly is removed and a second-type blade assembly including two cutting portions is mounted to the drive shaft to perform the cutting function. The two cutting portions of the second-type blade assembly are located at upper and lower positions along the rotation axis. In other words, the mounting assembly switches the lawn mower from a first-type blade assembly having a single cutting portion to a second-type blade assembly having two cutting portions, the two cutting portions being located at upper and lower positions along the rotation axis. It should be noted that the second-type blade assembly may include the first cutting portion of the first-type blade assembly, or may be formed as a separate, completely different blade assembly. When the second-type blade assembly includes the first cutting portion of the first-type blade assembly, the position of the first cutting portion relative to the drive shaft may remain unchanged or may vary. For example, the first type of blade assembly includes a first blade provided with a first cutting part, and the second type of blade assembly adds a second blade provided with a second cutting part on the basis of the first type of blade assembly, and the second blade is installed to the lower side or upper side of the first blade along the direction of the rotation axis through the installation assembly.

[0061] As another optional embodiment, the lawn mower system includes a blade assembly and a lawn mower body, and the lawn mower body includes a chassis, a motor, and a battery pack. The motor is mounted on the chassis, and the battery pack supplies power to the motor. The lawn mower system also includes a first-type blade assembly and a second-type blade assembly. The motor drives the first-type blade assembly or the second-type blade assembly to rotate about the rotation axis. The first-type blade assembly includes a first blade, and the first blade forms a first cutting portion for mowing grass. The second-type blade assembly includes a first blade and a second blade, and the first blade forms a first cutting portion for mowing grass. The second blade forms a second cutting portion for mowing grass. Wherein, along the rotation axis, the second cutting portion is located below the first cutting portion. The lawn mower body can be adapted to the first-type blade assembly or the second-type blade assembly. The lawn mower body can be adapted to install the second-type blade assembly after the first-type blade assembly is disassembled, or it can be adapted to install the second-type blade assembly when the second-type blade assembly is disassembled.

[0062] The blade assembly 11 in the present invention is driven by friction, and the mounting assembly 16 includes a driving member 161 for driving the blade assembly 11 to rotate about the rotation axis 101. The driving member 161 is connected to the drive shaft 14 and is driven by the drive shaft 14. The driving member 161 and the blade assembly 11 are transmitted by static friction. Specifically, the driving member 161 is a flange, and the flange and the drive shaft 14 are fixedly connected in the radial direction. The blade assembly 11 is in surface contact with the flange in a plane perpendicular to the rotation axis 101. The mounting assembly 16 also includes a clamping assembly 162 for clamping the blade assembly 11 to the surface of the driving member 161 in the direction of the rotation axis 101. The clamping assembly 162 is mounted to the drive shaft 14 and is fixedly and detachably connected to the drive shaft 14 in the direction of the rotation axis 101. Specifically, the drive shaft 14 and the flange form a flat fit, and the clamping assembly 162 includes a bolt 162a and a first gasket 162b. The flange, blade assembly 11, first gasket 162b and bolt 162a fit tightly from top to bottom along the rotation axis 101, wherein the flange, blade assembly 11 and first gasket 162b are mounted on the drive shaft 14, and the bolt 162a is inserted into the drive shaft 14 to form a threaded connection with the drive shaft 14.

[0063] like Figure 5 As shown, when the mounting assembly 16 is in the first mounting state, the bottom surface of the driving member 161 is in close contact with the upper surface of the blade assembly 11. The first gasket 162b and the driving shaft 14 also form a flat fit.

[0064] like Figure 7 、 Figure 8 As shown, the mounting assembly 16 is in the second state. Figure 7 In the embodiment, only the first blade 111 is mounted to the drive shaft 14 via the mounting assembly 16. In this embodiment, the position of the first blade 111 relative to the drive shaft 14 along the rotation axis 101 is fixed by adding a second gasket 162c. Figure 8 As shown, as an optional embodiment, the mounting assembly 16 further includes a fan 15, which is fixedly connected to the driving member 161. Specifically, the fan 15 is mounted on the outside of the driving member 161 and is coaxially connected to the driving member 161. The fan 15 is driven by the driving member 161, and the driving member 161 is formed with a driving portion 161a (such as Figure 5As shown), the driving portion 161a specifically protrudes radially from the driving member 161, and a groove that closely fits the driving portion 161a is formed on the fan 15. Along the direction of the rotation axis 101, the lower surface of the fan 15 is located below the lower surface of the driving member 161. When only the first blade 111 or the second blade 112 is mounted to the drive shaft 14, the fan 15 is in surface contact with the blade assembly 11, and the lower surface of the fan 15 abuts against the upper surface of the blade assembly 11, and the fan 15 and the blade assembly 11 form a friction drive. It can be understood that, as another optional embodiment, the connection between the mounting assembly 16 and the blade assembly 11 can simultaneously adopt the connection methods in the above two embodiments, and the first blade 111 or the second blade 112 is pressed by the clamping assembly 162 including the fan 15 and the second gasket 162c.

[0065] It should be noted that the structure of mounting assembly 16 and its connection method with blade assembly 11 are not limited to the above-described embodiments. For example, when mounting assembly 16 is in the second mounting state, first gasket 162b may be replaced with a second gasket 162c having a thickness greater than that of first gasket 162b. Any other simple adjustment or replacement based on mounting assembly 16 of the present invention that can achieve a switching of mounting states should be considered within the scope of protection of the present invention. Mounting assembly 16 may include multiple components, and may include different components when mounting assembly 16 is in the first mounting state and the second mounting state, respectively.

[0066] The driving member 161 and the blade assembly 11 form a surface contact in a plane perpendicular to the rotation axis 101; the contact area between the driving member 161 and the blade assembly 11 is greater than or equal to 100 mm 2 And less than or equal to 1000 mm 2 Preferably, the contact area between the drive member 161 and the blade assembly 11 is greater than or equal to 300 mm 2 and less than or equal to 500 mm 2 In this embodiment, the contact area between the flange and the blade assembly 11 is approximately 432 mm 2 Specifically, the contact area between the lower surface of the flange and the upper surface of the blade assembly 11 is approximately 432 mm 2 Accordingly, when the mounting assembly 16 is in the second mounting state and the fan 15 and the blade assembly 11 form a friction transmission, the fan 15 and the blade assembly 11 form a surface contact in a plane perpendicular to the rotation axis 101; the contact area between the fan 15 and the blade assembly 11 is greater than or equal to 100 mm 2 And less than or equal to 1000 mm 2 .

[0067] like Figures 4 to 6 as well as Figure 9As shown, the blade assembly 11 is formed with at least one mounting hole 113 that mates with the drive shaft 14. In this embodiment, when the blade assembly 11 forms a movable unit, the blade assembly 11 is formed with only one mounting hole 113 that mates with the drive shaft 14 to facilitate user installation. The mounting hole 113 is located approximately at the center of the blade assembly 11. The blade assembly 11 is centrally symmetrical about the center of the mounting hole 113, which makes the blade assembly 11 rotate more smoothly about the rotation axis 101 and avoids eccentric torque. Specifically, the first blade 111 and the second blade 112 are respectively formed with a first mounting hole 113a and a second mounting hole 113b. When the blade assembly 11 is mounted to the drive shaft 14, the first mounting hole 113a and the second mounting hole 113b overlap vertically along the rotation axis 101. As an alternative embodiment, the blade assembly 11 is formed with multiple mounting holes 113, and the mounting assembly 16 accordingly includes multiple connecting shafts that mate with the mounting holes 113 and are connected to the drive shaft 14.

[0068] The mounting assembly 16 contacts the blade assembly 11 to form at least one mounting surface 16a that is basically perpendicular to the rotation axis 101; when the blade assembly 11 cuts, at least one cutting surface 11a that is perpendicular to the rotation axis 101 is formed; at least one mounting surface 16a is located above the cutting surface 11a along the direction of the rotation axis 101. In this embodiment, the flange or fan 15 of the mounting assembly 16 and the first gasket 162b are in surface contact with the blade assembly 11 and form two upper and lower mounting surfaces 16a perpendicular to the rotation axis 101; when the blade assembly 11 includes the first blade 111 or the second blade 112, the first blade 111 or the second blade 112 rotates around the rotation axis 101 to form a cutting surface 11a, and the plane where the cutting surface 11a is located is the plane where the edge 111b of the first cutting part or the edge 112b of the second cutting part is located; when the blade assembly 11 includes the first blade 111 and the second blade 112, the first blade 111 and the second blade 112 rotate around the rotation axis 101 to form two upper and lower parallel cutting surfaces 11a, and the planes where the upper and lower cutting surfaces 11a are located are respectively the planes where the edge 111b of the first cutting part and the edge 112b of the second cutting part are located. In this embodiment, one mounting surface 16a is located above the two cutting surfaces 11a along the rotation axis 101, thereby avoiding the installation assembly 16 below the cutting surfaces 11a to the greatest extent possible. In fact, in this embodiment, the driving member 161 for driving the blade assembly 11 to rotate is located above the cutting surfaces 11a.

[0069] like Figure 9As shown, the blade assembly 11 further includes a connecting assembly 114 that connects the second blade 112 to the first blade 111 so that the blade assembly 11 forms a unit that can move together when not mounted on the drive shaft 14. After the connecting assembly 114 connects the second blade 112 to the first blade 111, the second cutting portion 112a and the first cutting portion 111a are located at different axial positions along the rotation axis 101. In other words, when the first blade 111 and the second blade 112 are not integrally formed, the first blade 111 and the second blade 112 are connected as a unit via the connecting assembly 114. It should be noted that when not mounted on the drive shaft 14, the first blade 111 and the second blade 112 can be fixedly connected or movably connected, and the first blade 111 can move relative to the second blade 112. When the blade assembly 11 is mounted on the drive shaft 14 and performs cutting as a unit, the first blade 111 is fixed relative to the second blade 112. At the same time, the connecting assembly 114 determines the relative position of the first cutting portion 111a and the second cutting portion 112a along the direction of the rotation axis 101. Specifically, the first cutting portion 111a is located above the second cutting portion 112a. In this embodiment, the first blade 111 is located above the second blade 112. The connecting assembly 114 allows the blade assembly 11 to be assembled and disassembled by the user as a whole, facilitating operation. At the same time, it also fixes the relative axial position of the first cutting portion 111a and the second cutting portion 112a, preventing the user from re-positioning the two cutting portions in the axial direction during assembly, and also preventing the user from installing the first blade 111 and the second blade 112 incorrectly or reversely, thereby preventing the user from installing the first blade 111 and the second blade 112 incorrectly, thereby providing a foolproof function.

[0070] When the connecting assembly 114 connects the second blade 112 to the first blade 111, the second blade 112 is fixed relative to the first blade 111 within a preset angle range. Preferably, the preset angle range is greater than or equal to 0 degrees and less than or equal to 20 degrees. Further, the preset angle range is greater than or equal to 5 degrees and less than or equal to 10 degrees. In other words, the connecting assembly 114 connects the first blade 111 and the second blade 112 so that the first blade 111 and the second blade 112 are fixedly connected or movably connected in the circumferential direction. When the first blade 111 and the second blade 112 are movably connected in the axial direction, the first blade 111 can rotate relative to the second blade 112 at an angle greater than or equal to 0 degrees and less than or equal to 10 degrees. The first blade 111 and the second blade 112 are detachably connected by the connecting assembly 114, which facilitates the later maintenance or replacement of the blade assembly 11.

[0071] Specifically, in this embodiment, the connecting assembly 114 comprises a common fastener, such as a bolt and nut, or a screw and nut. The blade assembly 11 is formed with at least one positioning portion 115 connected to the connecting assembly 114. The positioning portion 115 is used to define the phase angle range of the first blade 111 relative to the second blade 112. The connecting assembly 114 is mounted to the positioning portion 115. In this embodiment, the positioning portion 115 is a positioning hole formed on both the first blade 111 and the second blade 112. The number of positioning portions 115 is not limited, but preferably is greater than or equal to two. Specifically, the first blade 111 is formed with two diamond-shaped holes symmetrically about the rotation axis 101, and the second blade 112 is formed with two circular holes symmetrically about the rotation axis 101. The diamond-shaped holes mate with the diamond-shaped protrusions on the bolt head, and the circumferential circular holes mate with the bolt stud. The bolt and nut are locked together, thereby forming a fixed connection between the first blade 111 and the second blade 112, with a fixed phase angle in the circumferential direction and a fixed relative position in the axial direction. It should be noted that the positioning holes may also be other shapes such as square holes and waist-shaped holes; the matching manner of the positioning holes on the first blade 111 and the positioning holes on the second blade 112 and the connecting component 114 is not limited here.

[0072] The connecting assembly 114 includes a matching portion 114a that matches with the positioning portion 115. In this embodiment, the positioning portion 115 is a positioning hole, and the matching portion 114a is a bolt, specifically a screw rod of the bolt, which matches with the positioning hole to form an axial hole. The connecting assembly 114 also includes an axial fixing portion that fixes the position of the first blade 111 relative to the second blade 112 in a direction parallel to the rotation axis 101. In this embodiment, the connecting assembly 114 also includes an axial fixing portion that fixes the position of the first blade 111 relative to the second blade 112 in the direction of the rotation axis 101, specifically a bolt and a nut. Optionally, the axial fixing portion can be a magnetic element mounted to the first blade 111 and the second blade 112, which fixes the axial position of the first blade 111 relative to the second blade 112 by magnetic attraction. It can be understood that the specific structure of the matching portion 114a and the axial positioning portion 115 is not limited to the above-mentioned method.

[0073] As an optional embodiment, the mating portion of the connecting assembly is provided on a mounting member such as a fan or a flange, and is fixedly connected or integrally formed with the fan, flange, or other mounting member. For example, a driving portion is formed at the lower end of the fan for installing and positioning the blade assembly. Preferably, the connecting assembly further comprises a clamping member for axially clamping the blade assembly, the clamping member being connected to the blade assembly and forming surface contact with the blade assembly. In this case, the blade assembly can form either a friction drive with the drive shaft or a mechanical positioning drive, such as a flat position.

[0074] like Figure 4 、 Figure 5 、 Figure 10As shown, the positioning portion 115 roughly has a geometric center, and the distance from the geometric center to the rotation axis 101 is the positioning radius r. The positioning radius r is greater than or equal to 0 and less than or equal to 50 mm. Preferably, the positioning radius r of the positioning portion 115 is greater than or equal to the radius of the drive shaft 14 and less than or equal to 50 mm. In this embodiment, the positioning radius r of the positioning portion 115 is approximately 30 mm. When the positioning radius r of the positioning portion 115 is 0, that is, the geometric center of the positioning portion 115 coincides with the rotation axis 101, as an optional embodiment, a radial groove is provided on the drive shaft 14 for accommodating the positioning portion 115. Generally speaking, the positioning portion 115 is arranged outside the drive shaft 14, that is, the positioning radius r of the positioning portion 115 is greater than or equal to the radius of the drive shaft 14. For a positioning portion 115 with a regular shape, its geometric center is uniquely determined. For a positioning portion 115 with an irregular shape, a point located at the center of the positioning portion 115 can be roughly determined as its geometric center. Preferably, the ratio of the rotation diameter D of the blade assembly 11 to the positioning radius r of the positioning portion 115 is greater than or equal to 5 and less than or equal to 25. When the position of the positioning portion 115 is within the above range, the positioning effect of the positioning portion 115 is better. The rotation diameter is greater than or equal to 200 mm and less than or equal to 700 mm.

[0075] As an optional embodiment, the positioning hole is other positioning holes with incomplete positioning effects, such as an elliptical hole. The positioning hole can limit the rotation of the first blade 111 relative to the second blade 112 to a certain extent but cannot completely limit the rotation of the first blade 111 relative to the second blade 112, so that the blade assembly 11 has a certain adjustment space when encountering an obstacle, thereby enhancing the service life of the blade assembly 11.

[0076] The maximum length of a line connecting any two points of the projection of the first blade 111 in a plane perpendicular to the rotation axis 101 in a direction perpendicular to the rotation diameter D1 of the first blade 111 is equal to the width W1 of the first blade 111, and the ratio of the rotation diameter D1 of the first blade 111 to the width W1 of the first blade 111 is greater than or equal to 5 and less than or equal to 13. The maximum length of a line connecting any two points of the projection of the second blade 112 in a plane perpendicular to the rotation axis 101 in a direction perpendicular to the rotation diameter D2 of the second blade 112 is equal to the width W2 of the second blade 112, and the ratio of the rotation diameter D2 of the second blade 112 to the width W2 of the second blade 112 is greater than or equal to 5 and less than or equal to 13. Specifically, in this embodiment, the rotation diameter D1 of the first blade 111 is approximately 511 mm, the width W1 of the first blade 111 is approximately 51 mm, the rotation diameter D2 of the second blade 112 is approximately equal to the rotation diameter D1 of the first blade 111, and the width W2 of the second blade 112 is approximately equal to the width W1 of the first blade 111.

[0077] like Figure 9 、 Figure 10 As shown, at least one reinforcing rib 116 is formed on the surface of each of the first blade 111 and the second blade 112. In this embodiment, the first blade 111 and the second blade 112 each have two reinforcing ribs 116. The two reinforcing ribs 116 on the surface of the first blade 111 protrude upward, extend along the length of the first cutting portion 111a, and are symmetrical about the rotation axis 101; the two reinforcing ribs 116 on the surface of the second blade 112 protrude downward, extend along the length of the second cutting portion 112a, and are symmetrical about the rotation axis 101. The shape of the reinforcing ribs 116 is preferably elongated. The ratio of the rotation diameter D1 of the first blade 111 to the length a1 of a single reinforcing rib 116 is greater than or equal to 2.5 and less than or equal to 10; the ratio of the rotation diameter D1 of the first blade 111 to the total length of the multiple reinforcing ribs 116 is greater than or equal to 1.3 and less than or equal to 5; and the ratio of the width W1 of the first blade 111 to the width b1 of a single reinforcing rib 116 is greater than or equal to 2 and less than or equal to 5. Similarly, the ratio of the rotational diameter D2 of the second blade 112 to the length a1 of a single reinforcing rib 116 is greater than or equal to 2.5 and less than or equal to 10; the ratio of the rotational diameter D2 of the second blade 112 to the total length of the multiple reinforcing ribs 116 is greater than or equal to 1.3 and less than or equal to 5; and the ratio of the width W2 of the second blade 112 to the width b1 of a single reinforcing rib 116 is greater than or equal to 2 and less than or equal to 5. It should be noted that the length a1 of the reinforcing rib 116 refers to the maximum dimension of the projection of the reinforcing rib 116 onto a plane perpendicular to the rotation axis 101 in the direction of its extension, and the width b1 of the reinforcing rib 116 refers to the maximum dimension of the projection of the reinforcing rib 116 onto a plane perpendicular to the rotation axis 101 in the direction of its extension. The reinforcing ribs 116 are distributed centrally in the direction of extension of the first blade 111 or the second blade 112 and in a direction perpendicular to the direction of extension of the first blade 111 or the second blade 112, thereby enhancing the strength of the first blade 111 or the second blade 112. Of course, in other embodiments, the number, position and specific shape of the reinforcing ribs 116 are not limited thereto.

[0078] In this embodiment, the first blade 111 extends substantially along the first straight line; the second blade 112 extends substantially along the second curved line. Because the first blade 111 is positioned above the second blade 112 in the direction of the rotation axis 101, and the second curved line at least partially bends downward, sufficient cutting space is formed between the first blade 111 and the second blade 112. As an alternative embodiment, the first blade 111 extends substantially along the first curved line; the second blade 112 extends substantially along the second curved line. In other words, the first blade 111 and the second blade 112 extend along respective curved lines. Preferably, the first and second curves are two different curves having at least partially different curvatures, thereby forming sufficient cutting space between the first blade 111 and the second blade 112.

[0079] The length of the projection of the first cutting portion 111a on a plane perpendicular to the rotation axis 101 is greater than or equal to 10 mm and less than or equal to 600 mm; the length of the projection of the second cutting portion 112a on a plane perpendicular to the rotation axis 101 is greater than or equal to 10 mm and less than or equal to 600 mm. It should be noted that the length of the projection of the first cutting portion 111a on a plane perpendicular to the rotation axis 101 specifically refers to the length of the projection of the blade edge 111b of the first cutting portion on a plane perpendicular to the rotation axis 101. When the first blade 111 includes multiple first cutting portions 111a, the length of the projection of the first cutting portion 111a in a plane perpendicular to the rotation axis 101 is the sum of the lengths of the projections of the blade edges 111b of the multiple first cutting portions in a plane perpendicular to the rotation axis 101; similarly, the length of the projection of the second cutting portion 112a in a plane perpendicular to the rotation axis 101 specifically refers to the length of the projection of the blade edge 112b of the second cutting portion in a plane perpendicular to the rotation axis 101; when the second blade 112 includes multiple second cutting portions 112a, the length of the projection of the second cutting portion 112a in a plane perpendicular to the rotation axis 101 is the sum of the lengths of the projections of the blade edges 112b of the multiple second cutting portions in a plane perpendicular to the rotation axis 101. The length of the projection of the first cutting portion 111a in a plane perpendicular to the rotation axis 101 and the length of the projection of the second cutting portion 112a in a plane perpendicular to the rotation axis 101 are both greater than or equal to 10 mm and less than or equal to 600 mm. Furthermore, the length of the projection of the first cutting portion 111a in a plane perpendicular to the rotation axis 101 and the length of the projection of the second cutting portion 112a in a plane perpendicular to the rotation axis 101 are both greater than or equal to 20 mm and less than or equal to 400 mm. In this embodiment, the length of the projection of the first cutting portion 111a in a plane perpendicular to the rotation axis 101 is approximately 236 mm. Preferably, the length of the projection of the first cutting portion 111a in a plane perpendicular to the rotation axis 101 and the length of the projection of the second cutting portion 112a in a plane perpendicular to the rotation axis 101 are substantially equal.

[0080] The weight of the blade assembly 11 is greater than or equal to 0.35 kg and less than or equal to 1.8 kg. When the weight of the blade assembly 11 is within this numerical range, the load of the lawn mower 100 is small and the working efficiency is high. When the first blade 111 and the second blade 112 are formed separately and the mass of the first blade 111 is less than or equal to the second blade 112, the ratio of the weight of the first blade 111 to the weight of the second blade 112 is greater than or equal to 0.5 and less than or equal to 1; as an optional embodiment, the first blade 111 and the second blade 112 are formed separately and the mass of the second blade 112 is less than or equal to the first blade 111, and the ratio of the weight of the second blade 112 to the weight of the first blade 111 is greater than or equal to 0.5 and less than or equal to 1.

[0081] The battery pack includes a battery pack shell and a battery cell unit. The battery cell unit is arranged in the battery pack shell. The number of battery cells contained in the battery pack is N, in units. The weight M of the blade assembly 11 is in kilograms. The maximum value of the length of the line connecting any two points of the projection of the blade assembly 11 in a plane perpendicular to the rotation axis 101 and the projection of the rotation axis 101 in the plane is the rotation diameter D of the blade assembly 11; the unit is millimeters. The product of the rotation diameter D of the blade assembly 11, the number of battery cells N and the weight M of the blade assembly 11 is greater than or equal to 3.5×10 5 mm•pieces•grams and less than or equal to 7.3×10 7 mm • g; Further, the product of the rotation diameter D of the blade assembly 11, the number N of the battery cells and the weight M of the blade assembly 11 is greater than or equal to 7×10 5 mm•pieces•grams and less than or equal to 3.6×10 7 mm•pieces•grams; Furthermore, the product of the rotation diameter D of the blade assembly 11, the number N of the battery cells and the weight M of the blade assembly 11 is greater than or equal to 1.4×10 6 mm•pieces•grams and less than or equal to 1.8×10 7 mm·unit·gram. When the product of the rotation diameter D of the blade assembly 11, the number of battery cells N, and the weight M of the blade assembly 11 falls within the above numerical range, the lawn mower 100 has a smaller load or higher cutting efficiency. It should be noted that the blade assembly 11 here refers to the total weight of the blade assembly 11 including the first blade 111 and the second blade 112. When the lawn mower 100 includes multiple battery packs, the number of battery cells N here refers to the total number of battery cells included in all battery packs. In this embodiment, the rotation diameter D of the blade assembly 11 is approximately 508 mm, and the number of battery cells N included in the battery pack is 10. It should be noted that the number of battery cells N refers to the number of battery cells included in the battery pack that provides power to the motor 13 used to drive the blade assembly 11. When the lawn mower 100 is a self-propelled lawn mower, it typically also includes a self-propelled motor for driving the wheels. In this case, the motor 13 should not include a self-propelled motor. That is to say, the battery pack here does not include the battery pack that powers the self-propelled motor.

[0082] As an optional embodiment, the larger value of the rotation diameter D1 of the first blade 111 and the rotation diameter D2 of the second blade 112 is defined as the transverse dimension L of the blade assembly 11. The battery pack includes the number N of battery cells and the weight M of the blade assembly 11. The product of the transverse dimension L of the blade assembly 11, the number N of battery cells and the weight M of the blade assembly 11 is greater than or equal to 3.5×10 5mm•pieces•grams and less than or equal to 7.3×10 7 mm • g; further, the product of the lateral dimension L of the blade assembly 11, the number N of the battery cells and the weight M of the blade assembly 11 is greater than or equal to 7×10 5 mm•pieces•grams and less than or equal to 3.6×10 7 mm·piece·gram; Furthermore, the product of the lateral dimension L of the blade assembly 11, the number N of the battery cell units and the weight M of the blade assembly 11 is 1.4×10 6 mm•pieces•grams and less than or equal to 1.8×10 7 Millimeters. Pieces. Grams.

[0083] The output torque of motor 13 is greater than or equal to 0 and less than or equal to 10 Nm. Furthermore, the output torque of motor 13 is greater than or equal to 3 Nm and less than or equal to 8 Nm. In this embodiment, the output torque of motor 13 is approximately 4 Nm. When the output torque of motor 13 falls within the above value range, lawn mower 100 has higher cutting efficiency or cutting capacity.

[0084] In the present invention, the moment of inertia of the blade assembly 11 is greater than or equal to 8000 kg·mm² and less than or equal to 23000 kg·mm²; further, the moment of inertia of the blade assembly 11 is greater than or equal to 15000 kg·mm² and less than or equal to 20000 kg·mm².

[0085] Furthermore, under certain operating conditions, the lawn mower 100 may not only need to cut vegetation but also need to break it up or collect the cut vegetation into a collection device. By employing the specific structural design of the blade assembly 11 described above, the lawn mower 100 has a higher grass-chopping or grass-discharging capability. The lawn mower 100 is also provided with a collection device (not shown) for collecting the cut vegetation. The collection device is connected to the chassis 12. Specifically, the chassis 12 has a grass outlet formed therein for the cut vegetation to enter the collection device from the chassis 12. The collection device is connected to the grass outlet. When the blade assembly 11 rotates at a speed with a tip linear velocity greater than or equal to 40 m / s and less than or equal to 100 m / s, the average wind speed at the grass outlet is greater than or equal to 3 m / s and less than or equal to 25 m / s. Furthermore, when the blade assembly 11 rotates at a speed with a tip linear velocity greater than or equal to 40 m / s and less than or equal to 100 m / s, the average wind speed at the grass outlet is greater than or equal to 5 m / s and less than or equal to 15 m / s. When the average wind speed output at the grass outlet meets the above numerical range, it is beneficial to improve the grass chopping and grass removal capabilities of the lawn mower 100. It should be noted that the tip linear velocity of the blade assembly 11 refers to the linear velocity of the point at which the distance between the blade assembly 11 and the rotation axis 101 is the largest when the blade assembly 11 rotates about the rotation axis 101.

[0086] Figure 11 A schematic diagram shows a lawn mower blade assembly 21 mounted to a drive shaft 24 in a second embodiment of the present invention. This embodiment differs from the first embodiment in that the blade assembly 21 of this embodiment does not include a connecting assembly. Instead, the blade assembly 21 is formed with a positioning portion 213 and a mating portion 214 for defining the phase angle range of the first blade 211 and the second blade 212. The remaining structure of the lawn mower of this embodiment is the same as that of the first embodiment. One of the first blade 211 and the second blade 212 is formed with a positioning portion 213, and the other is formed with a mating portion 214 for mating with the positioning portion 213. When the positioning portion 213 and the mating portion 214 engage with each other, the second blade 212 is fixed relative to the first blade 211 in a circumferential direction around the rotation axis 201 or can rotate within a predetermined angular range. In other words, no connecting assembly is required; the positioning portion 213 and the mating portion 214 alone define the circumferential position of the second blade 212 relative to the first blade 211 in the rotation axis 201. Specifically, in this embodiment, a mating portion 214 and a positioning portion 213 are respectively provided on the first blade 211 and the second blade 212. The positioning portion 213 is a protrusion provided on the second blade 212 and protruding from the upper surface of the second blade 212. The mating portion 214 is a through hole provided on the first blade 211. When the first blade 211 and the second blade 212 are mounted on the drive shaft 24, the protrusion passes through the through hole and cooperates with the through hole, thereby achieving the positioning of the first blade 211 relative to the second blade 212 in the circumferential direction of the rotation axis 201. The positioning portion 213 can be a regular three-dimensional structure such as a cylinder or other irregular shapes; the mating portion 214 can be a through hole with a circular cross-section or any other through hole that can cooperate with the positioning portion 213.

[0087] It can be understood that the specific structure of the positioning portion 213 and the matching portion 214 is not limited to the above-mentioned protrusions and through holes. For example, optionally, the positioning portion 213 is a protrusion protruding from the second blade 212, and the matching portion 214 is an accommodating portion formed with an upward protrusion from the surface of the first blade 211. The accommodating portion can accommodate at least the positioning portion 213 or cooperate with the positioning portion 213, thereby realizing the positioning of the first blade 211 relative to the second blade 212.

[0088] The number of positioning parts 213 and matching parts 214 is not limited. Preferably, the positioning parts 213 and matching parts 214 are respectively an even number and are symmetrically arranged about the rotation axis 201, so that the force acting on the first blade 211 and the second blade 212 is more uniform, so that the position of the first blade 211 relative to the second blade 212 is more stable.

[0089] Similar to the first embodiment, the positioning portion 213 in this embodiment has a roughly defined geometric center. The distance from the geometric center to the rotation axis 201 is the positioning radius r'. The positioning radius r' of the positioning portion 213 is greater than or equal to 0 and less than or equal to 50 mm. Preferably, the positioning radius r' of the positioning portion 213 is greater than or equal to the radius of the drive shaft 24 and less than or equal to 50 mm. In this embodiment, the positioning radius r' of the positioning portion 213 is approximately 30 mm. When the positioning radius r' is 0, that is, the geometric center of the positioning portion 213 coincides with the rotation axis 201, as an optional embodiment, a radial groove is provided in the drive shaft 24 to accommodate the positioning portion 213. Generally speaking, the positioning portion 213 is disposed outside the drive shaft 24, that is, the positioning radius r' of the positioning portion 213 is greater than or equal to the radius of the drive shaft 24. For a regularly shaped positioning portion 213, its geometric center is uniquely determined. For an irregularly shaped positioning portion 213, a point located at the center of the positioning portion 213 can be roughly determined as its geometric center. The maximum value of the length of the line connecting any two points of the projection of the blade assembly 21 in a plane perpendicular to the rotation axis 201 and the projection of the rotation axis 201 in the plane is the rotation diameter of the blade assembly 21; the rotation diameter is greater than or equal to 200 mm and less than or equal to 700 mm, and further, the rotation diameter is greater than or equal to 250 mm and less than or equal to 560 mm. Preferably, the ratio of the rotation diameter of the blade assembly 21 to the positioning radius r' of the positioning portion 213 is greater than or equal to 5 and less than or equal to 25. When the position of the positioning portion 213 is within the above range, the positioning effect of the positioning portion 213 is better. Correspondingly, the mating portion 214 also roughly has a geometric center, and the distance from the geometric center to the rotation axis 201 is the positioning radius r' of the mating portion 214. The positioning radius r' of the mating portion 214 is greater than or equal to 0 and less than or equal to 50 mm. Preferably, the positioning radius r' of the mating portion 214 is greater than or equal to the radius of the drive shaft 24 and less than or equal to 50 mm.

[0090] Figure 12A schematic diagram of a blade assembly and connecting assembly for a lawn mower according to a third embodiment of the present invention is shown. The third embodiment differs from the first and second embodiments in the structure of the connecting assembly and the connection method between the connecting assembly and the blade assembly; all other similarities apply to this embodiment. The lawn mower includes a connecting assembly 312, which comprises a first connecting portion 312a for connecting a first blade 311 and a second connecting portion 312b for connecting a second blade 313. The second blade 313 is fixed or rotatable within a predetermined angular range relative to the first blade 311 in the circumferential direction about the rotation axis 301. In other words, the first blade 311 and the second blade 313 are fixed or rotatable within a predetermined angular range in the circumferential direction about the rotation axis 301 via the connecting assembly 312; the first blade 311 and the second blade 313 themselves are not connected. Specifically, in this embodiment, the connecting assembly 312 is a flange, but is not limited to a flange. The connecting assembly 312 is fixedly connected to the first blade 311 and the second blade 313 in the upper and lower directions, respectively, thereby maintaining a fixed phase angle between the first blade 311 and the second blade 313. Of course, the connection between the connecting component 312 and the first blade 311 and the second blade 313 can also be movable, so that the second blade 313 can rotate relative to the first blade 311 in the circumferential direction around the rotation axis 301 within a preset angle range.

[0091] Figures 13 to 16A schematic diagram of a lawn mower blade assembly 41 according to a fourth embodiment of the present invention is shown. Similarly, blade assembly 41 rotates about rotation axis 401. The blade assembly 41 of this embodiment differs from the first embodiment only in the specific structure of the second blade 412 of blade assembly 41. Similarities with the first embodiment apply to this embodiment. Parallel to rotation axis 401, second cutting portion 412a is located below first cutting portion 411a. Circumferentially around rotation axis 401, first cutting portion 411a is located forward of second cutting portion 412a. Second cutting portion 412a is located on the forward edge of second blade 412. It should be noted that the front side in the circumferential direction around the rotation axis 401 refers to the side that first contacts the vegetation when the blade assembly 41 rotates in the first direction A' about the rotation axis 401. In other words, the first cutting portion 411a and the second cutting portion 412a first contact the vegetation, and the second cutting portion 412a is located at the edge of the second blade 412 that first contacts the vegetation. In this embodiment, the two first cutting portions 411a are respectively located at the front sides of the two ends of the first blade 411, and the two first cutting portions 411a are centrally symmetrical about the rotation axis 401; the two second cutting portions 412a are respectively located at the front sides of the two ends of the second blade 412, and the two second cutting portions 412a are centrally symmetrical about the rotation axis 401. In fact, the blade assembly 41 as a whole is centrally symmetrical about the rotation axis 401.

[0092] The rear side of the second blade 412 is further formed with a first guide portion 412b and a second guide portion 412c for guiding the airflow to move upward. In other words, the second blade 412 is formed with a first guide portion 412b and a second guide portion 412c on the side opposite to the second cutting portion 412a in the circumferential direction of the rotation axis 401, for guiding the airflow upward. It should be noted that the first guide portion 412b and the second guide portion 412c here refer to two partial entities that are at least partially separated. In this embodiment, the first guide portion 412b and the second guide portion 412c are both integrally formed with the second blade 412, first and generally extending in a direction perpendicular to the length of the second blade 412, and the first guide portion 412b and the second guide portion 412c are arranged in sequence along the length of the second blade 412. Of course, the first guide portion 412b and the second guide portion 412c can also be formed separately from the second blade 412 and fixedly connected to the second blade 412.

[0093] Each second cutting portion 412a corresponds to a first guide portion 412b and a second guide portion 412c, and the first guide portion 412b and the second guide portion 412c are arranged on the rear side of the same end of the second cutting portion 412a. In this embodiment, since the second blade 412 is provided with two second cutting portions 412a, two first guide portions 412b and two second guide portions 412c are formed, and the two first guide portions 412b and the two second guide portions 412c are respectively centrally symmetrical about the rotation axis 401.

[0094] The first guide portion 412b is bent upward along a first curved surface, and the second guide portion 412c is bent upward along a second curved surface different from the first curved surface. As an optional embodiment, at least part of the first guide portion 412b and at least part of the second guide portion 412c have different curvatures. The first guide portion 412b and the second guide portion 412c can each have a fixed curvature, or the curvature of the first guide portion 412b and the second guide portion 412c can change according to a certain rule or can change irregularly, which is not limited here. In this embodiment, the first guide portion 412b and the second guide portion 412c each have a changing curvature. Preferably, the radius of curvature of any point of the first guide portion 412b and the second guide portion 412c is greater than or equal to 0 and less than or equal to 100 mm. Further, the radius of curvature of any point of the first guide portion 412b and the second guide portion 412c is greater than or equal to 0 and less than or equal to 60 mm.

[0095] The second blade 412 includes at least a first guide portion 412b and a second guide portion 412c. In this embodiment, the second blade 412 is further provided with a third guide portion. It is understandable that the second blade 412 can also be provided with a fourth guide portion and multiple guide portions, and the multiple guide portions are arranged in sequence along the extension direction of the second blade 412.

[0096] The first guide portion 412b and the second guide portion 412c are both flanges that are turned upward from the middle of the second blade 412. The position where the first guide portion 412b starts to turn upward is the first root portion 412d, and the position where the second guide portion 412c starts to turn upward is the second root portion 412e. The first root portion 412d and the second root portion 412e are roughly located on the same straight line, and the straight line intersects obliquely with the extension line of the blade edge of the second cutting portion 412a. The intersection angle β formed by the straight line and the extension line of the blade edge of the second cutting portion 412a is greater than or equal to 0 and less than or equal to 40 degrees. Furthermore, the intersection angle formed by the extension line of the blade edge of the second cutting portion 412a is greater than or equal to 0 and less than or equal to 15 degrees. In this embodiment, the intersection angle formed by the straight line and the extension line of the second cutting portion 412a is approximately 6.9 degrees.

[0097] The outer sides of the first guide portion 412b and the outer sides of the second guide portion 412c extend substantially along the same straight line, which intersects obliquely with the extension of the second cutting portion 412a. The outer side of the first guide portion 412b refers to the edge opposite the first root portion 412d, while the outer side of the second guide portion 412c refers to the edge opposite the second root portion 412e. In this embodiment, the outer sides of the first guide portion 412b and the second guide portion 412c extend substantially parallel to the straight line between the first root portion 412d and the second root portion 412e.

[0098] In this embodiment, cutting edges are formed on the outer sides of the first guide portion 412b and the second guide portion 412c to further cut vegetation and enhance the mower's grass-chopping capability. It should be noted that the cutting edges on the first guide portion 412b and the second guide portion 412c do not necessarily need to be conventional blade structures; they only need to have a certain degree of cutting capability.

[0099] Figure 17 This is a schematic diagram of a partial structure of a lawn mower according to the fifth embodiment of the present invention. The difference between this embodiment and the first embodiment of the present invention lies in the specific structures of the blade assembly 51 and the mounting assembly 56. The similarities with the first embodiment can be applied to this embodiment.

[0100] like Figures 17 to 19 As shown, the motor drives the blade assembly 51 to rotate about the rotation axis 501. The blade assembly 51 includes a first cutting portion 511a for cutting vegetation and a second cutting portion 512a for cutting vegetation. The second cutting portion 512a is located below the first cutting portion 511a in a direction parallel to the rotation axis 501. In this embodiment, the blade assembly 51 includes a first blade 511 and a second blade 512. The first cutting portion 511a is provided on the first blade 511, and the second cutting portion 512a is provided on the second blade 512. The first blade 511 is mounted above the second blade 512 along the direction of the rotation axis 501. The mounting assembly 56 includes a driving member 561 for driving the blade assembly 51 to rotate about the rotation axis 501. The blade assembly 51 is detachably connected to the driving member 561. Specifically, the driving member 561 is connected to the driving shaft 54 and rotates synchronously with the driving shaft 54. The driving member 561 and the driving shaft 54 form a fixed connection along the circumference of the rotation axis 501, such as a flat connection or a threaded connection.

[0101] In this embodiment, the mounting assembly 56 further includes a driving portion 561a, which is fixedly connected to the driving member 561 or is integrally formed with the driving member 561; the driving portion 561a is connected to the blade assembly 51 so that the blade assembly 51 is fixedly connected relative to the driving member 561 along the circumference of the rotation axis 501 or the blade assembly 51 can rotate relative to the driving member 561 along the circumference of the rotation axis 501 within a predetermined angular range. Specifically, the driving portion 561a is connected to the first blade 511 and the second blade 512 respectively and drives the first blade 511 and the second blade 512 to rotate synchronously with the driving portion 561a. There is no restriction on the location of the driving portion 561a and the number of the driving portions 561a. In this embodiment, two driving portions 561a are respectively provided on either side of the rotation axis 501. The first blade 511 and the second blade 512 are stacked together along the rotation axis 501 and at least partially contact each other. The two driving portions 561a are connected to the first blade 511 and the second blade 512. Positioning holes are formed on the first blade 511 and the second blade 512 to cooperate with the two driving portions 561a. One of the driving portions 561a is substantially cylindrical and is rotationally connected to the first blade 511 and the second blade 512. The other driving portion 561a is flatly connected to the first blade 511 and the second blade 512. It is understood that only one driving portion 561a can be provided and connected to the blade assembly 51 in a flat manner; alternatively, two cylindrical driving portions 561a can be provided and connected to the blade assembly 51.

[0102] The mounting assembly 56 also includes a clamping assembly 562 and a fastening assembly 563; the clamping assembly 562 is used to clamp the blade assembly 51 along the direction of the rotation axis 501, and the blade assembly 51 is arranged between the driving member 561 and the clamping assembly 562 in a direction parallel to the rotation axis 501; the fastening assembly 563 is used to fix the position of the blade assembly 51 relative to the driving member 561 in a direction parallel to the rotation axis 501, and the fastening assembly 563 is detachably connected to the drive shaft 54. In this embodiment, the clamping assembly 562 is specifically one or more metal gaskets, which are in at least partial contact with the blade assembly 51; the fastening assembly 563 can be a nut, screw, bolt, etc., which is connected to the drive shaft 54 and abuts against the clamping assembly 562. In this embodiment, the drive shaft 54 passes through the blade assembly 51 and the clamping assembly 562, and the nut serves as the fastening assembly 563 to form a threaded connection with the drive shaft 54. It can be understood that when the fastening assembly 563 includes a bolt or a screw, etc., the fastening assembly 563 can pass through the blade assembly 51 and / or the clamping assembly 562, and the fastening assembly 563 and the drive shaft 54 form a fixed connection and a detachable connection.

[0103] The mounting assembly 56 also includes an insulating member 564 for insulating the blade assembly 51 from the drive shaft 54. The insulating member 564 is made of an insulating material. The insulating member 564 is disposed between the clamping assembly 562 and the blade assembly 51 along the direction of the rotation axis 501. The first blade 511 and the second blade 512 are both disposed between the drive member 561 and the insulating member 564. In this embodiment, the insulating member 564 is in surface contact with both the blade assembly 51 and the clamping assembly 562. A groove 564a is formed at the bottom of the insulating member 564 along the direction of the rotation axis 501, and the clamping assembly 562 is embedded in the groove 564a. The drive shaft 54 or the fastening assembly 563 passes through the insulating member 564.

[0104] In this embodiment, the lawn mower does not include a connecting assembly to connect the first blade 511 and the second blade 512 into a single unit before installation. In other words, the first blade 511 and the second blade 512 are two independently formed and mounted blades, each mounted to the drive shaft 54 and connected by the mounting assembly 56. In fact, in this embodiment, the connection of the blade assembly 51 via the drive portion 561a ensures that the phase angle between the first blade 511 and the second blade 512 remains substantially constant.

[0105] Figure 20 The sixth embodiment of the present invention is a schematic diagram of a partial structure of a lawn mower. The difference between this embodiment and the fifth embodiment of the present invention lies in the specific structure of the mounting assembly 66. The same points as the fifth embodiment can be applied to this embodiment.

[0106] like Figures 20 to 22 As shown, specifically, the difference between the mounting assembly 66 in this embodiment and the mounting assembly 66 in the sixth embodiment lies in the specific structure of the insulating member 664. In this embodiment, two grooves, an upper groove 664a and a lower groove 664b, are provided above and below the insulating member 664 along the direction of the rotation axis 601. The first blade 611 and the second blade 612 are disposed in the upper groove 664a, and the clamping assembly 662 is disposed in the lower groove 664b. The shape of the upper groove 664a conforms to the blade assembly, ensuring that the first and second blades are aligned at a predetermined phase angle along the circumference of the rotation axis 601. Similar to the sixth embodiment, the driving member 661 is provided with a driving portion 661a. In this embodiment, the design of the insulating member 664 not only provides better insulation between the blade assembly 61 and the drive shaft, but also helps maintain the blade assembly 61 at a fixed phase angle, preventing slippage. Furthermore, it also facilitates the driving member 661 to more efficiently drive the blade assembly 61.

[0107] Figure 23The figure shows a partial structure diagram of a lawn mower according to a seventh embodiment of the present invention. The difference between this embodiment and the sixth embodiment of the present invention lies in the specific structure of the mounting assembly 76. The similarities with the sixth embodiment can be applied to this embodiment.

[0108] like Figures 23 to 25 As shown, specifically, the mounting assembly 76 in this embodiment differs from the mounting assembly 76 in the sixth embodiment in the specific structures of the driving member 761 and the insulating member 764. In this embodiment, the driving member 761 drives the blade assembly 71 through friction. Specifically, the driving member 761 and the blade assembly 71 are at least partially in contact via a pressing assembly and a fastening assembly. In this embodiment, the driving member 761 and the blade assembly 71 are in surface contact and pressed against each other, with a certain amount of positive pressure generated between them along the rotation axis 701. When the drive shaft drives the driving member 761 to rotate along the rotation axis 701, the blade assembly 71 rotates along the rotation axis 701 due to the friction force acting circumferentially along the rotation axis 701. In other words, the driving member 761 does not need to have a driving portion for driving the blade assembly 71, nor does the blade assembly need to have a positioning hole for the driving portion. In fact, the driving member 761 drives the first blade 711 through friction, and the first blade 711 drives the second blade 712 by driving the insulating member 764. The insulating member 764 is disposed between the first blade 711 and the second blade 712. The insulating member 764 is also formed with an upper groove 764a and a lower groove 764b. The first blade 711 is disposed in the upper groove 764a, and the second blade 712 is disposed in the lower groove 764b. In other words, the first blade 711 is disposed between the driving member 761 and the insulating member 764; the second blade 712 is disposed between the insulating member 764 and the pressing assembly 762. Preferably, the upper groove 764a and the lower groove 764b are respectively attached to the edges of the first blade 711 and the second blade 712, so that the first blade 711 and the second blade 712 form a phase angle of a certain angle. The pressing assembly 762 is pressed against the second blade 712. Specifically, the pressing assembly 762 is attached to the lower surface of the second blade 712.

[0109] Figure 26A schematic diagram of a lawn mower according to an eighth embodiment of the present invention illustrates a partial structure. This embodiment differs from the fifth embodiment in the specific structures of the blade assembly 81 and the mounting assembly 86. The similarities with the fifth embodiment apply to this embodiment. The blade assembly 81 includes an integrally formed second blade 812, which is provided with a second cutting portion 812a. The first cutting portion 811a is provided on at least two separate first blades 811. Along the rotation axis 801, the first blades 811 are positioned above the second blades 812. Specifically, the two first blades 811 are positioned on either side of the rotation axis 801 and are fixedly connected to the second blades 812. Preferably, the first blades 811 are detachably connected to the second blades 812. It is understood that, as an alternative embodiment, the first blade 811 is a single-piece blade, and the second blade 812 is a plurality of separate blades, each fixedly connected to the first blade 811. The first cutting portion 811a and the second cutting portion 812a are provided on the first blade 811 and the second blade 812, respectively. As an alternative embodiment, the first blade 811 and the second blade 812 are integrally formed, but the first cutting portion 811a and the second cutting portion 812a are respectively provided on the first blade 811 and the second blade 812. In other words, the blade assembly 81 is a single integral blade, but is provided with a plurality of first cutting portions 811a and second cutting portions 812a distributed vertically along the rotation axis 801.

[0110] In this embodiment, the driving member 861 is provided with a driving portion, and the blade assembly is provided with a positioning hole that cooperates with the driving portion. The driving member 861 drives the blade assembly 81 to rotate via the driving portion. Specifically, the driving portion is connected to the first blade 811. The shape and number of the driving portions are not limited. As an optional embodiment, the driving portion is not required on the driving member 861. The driving member 861 is closely attached to the blade assembly 81, and the blade assembly 81 is driven to rotate about the rotation axis 801 through friction.

[0111] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any form, and any technical solutions obtained by equivalent replacement or equivalent transformation fall within the scope of protection of the present invention.

Claims

1. A lawn mower comprising: a blade assembly for performing a cutting function; a chassis, formed with a receiving space for receiving at least a portion of the blade assembly; Its characteristics are: The lawn mower further comprises: A motor, used for driving the blade assembly to rotate about a rotation axis; A battery pack, used to provide a power source for the motor; Wherein, the blade assembly includes: a first blade for mowing grass, formed with a first cutting portion; a second blade for mowing grass, formed with a second cutting portion; The second cutting portion is located below the first cutting portion in a direction parallel to the rotation axis; The battery pack includes: Battery pack housing; A battery cell unit is arranged in the battery pack shell; The maximum value of the length of the line connecting any two points of the projection of the blade assembly in a plane perpendicular to the rotation axis and the projection of the rotation axis in the plane is the rotation diameter of the blade assembly; wherein the product of the rotation diameter D of the blade assembly, the number N of battery cells contained in the battery pack and the weight M of the blade assembly is greater than or equal to 3.5×10 5 mm•g and less than or equal to 7.3×10 7 mm•g.

2. The lawn mower according to claim 1, wherein: The product of the rotation diameter D of the blade assembly, the number N of the battery cells and the weight M of the blade assembly is greater than or equal to 7×10 5 mm•g and less than or equal to 3.6×10 7 mm•g.

3. The lawn mower according to claim 2, characterized in that: The product of the rotation diameter D of the blade assembly, the number N of the battery cells and the weight M of the blade assembly is greater than or equal to 1.4×10 6 mm•g and less than or equal to 1.8×10 7 mm•g.

4. The lawn mower according to claim 1, wherein: The first blade and the second blade are integrally formed or separately formed.

5. The lawn mower according to claim 1, wherein: The output torque of the motor is greater than or equal to 0 and less than or equal to 10 N·m.

6. The lawn mower according to claim 1, characterized in that: The output torque of the motor is greater than or equal to 3 N·m and less than or equal to 8 N·m.

7. The lawn mower according to claim 1, wherein: The lawn mower further includes a fan; the fan is fixedly connected to the output shaft of the motor and rotates about the rotation axis; the fan is mounted above the blade assembly and abuts against the blade assembly.

8. The lawn mower according to claim 1, wherein: When the tip linear velocity of the blade assembly is greater than or equal to 40 m / s and less than or equal to 100 m / s, the average wind speed at the grass outlet is greater than or equal to 3 m / s and less than or equal to 25 m / s.

9. The lawn mower according to claim 1, characterized in that: The lawn mower also includes a control system for controlling the operation of the motor. When the lawn mower is idling, the sum of the input power of the motor, the input power of the control system, and the input power of the blade assembly is the idling input power of the lawn mower; the idling input power is greater than or equal to 100W and less than or equal to 380W.

10. The lawn mower according to claim 1, wherein: The moment of inertia of the blade assembly is greater than or equal to 8000 kg·mm² and less than or equal to 23000 kg·mm².

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