CN115868310A

CN115868310A - Cutting device and lawn mower

Info

Publication number: CN115868310A
Application number: CN202211488391.7A
Authority: CN
Inventors: 亨利克·琼森; 蒲志高
Original assignee: Globe Jiangsu Co Ltd
Current assignee: Globe Jiangsu Co Ltd
Priority date: 2022-11-25
Filing date: 2022-11-25
Publication date: 2023-03-31

Abstract

The invention provides a cutting device and a mower, wherein the cutting device comprises a driving assembly, a cutting assembly and a flat plate assembly, the driving assembly comprises a driving motor, a driving shaft extending out of the driving motor and a driving piece assembled at the tail end of the driving shaft, and the cutting assembly comprises a cutting disc, an extending shaft and a blade arranged on the cutting disc; the flat plate component comprises a flat plate and a connecting cover; wherein, the one end of extending the axle with cutting disc and driving piece fixed connection, the other end stretch into in the connecting cover with connecting cover swing joint, the axis that extends the axle is located same straight line with the axis of drive shaft to at the driving motor drive when the drive shaft rotates, can drive through the driving piece and extend axle and cutting disc synchronous rotation, make the blade carry out the cutting action, and dull and stereotyped subassembly then keeps motionless. The invention not only can reduce the manufacturing cost on the basis of realizing the same function, but also can reduce the maintenance cost after serious abrasion occurs.

Description

Cutting device and lawn mower

Technical Field

The invention relates to a cutting device and a mower, and belongs to the technical field of garden tools.

Background

Robotic lawnmowers have greatly facilitated the maintenance of lawns since their release on the market, however, while they are as helpful as most devices in trimming lawns, they still require some maintenance and upkeep and may incur some cost during their useful life.

Especially to motor drive shaft, the enough length that current motor drive shaft set up to with the cutting dish cooperation, drive the cutting dish and rotate then realize the cutting action. However, after a period of use, there is a great deal of wear between the motor drive shaft and the cutting disc, so that the motor drive shaft cannot be used any further, and the replacement cost of the motor drive shaft is very high.

In view of the above, there is a need for an improved lawn mower to solve the above problems.

Disclosure of Invention

The invention aims to provide a novel cutting device, which can reduce the maintenance cost after abrasion.

To achieve the above object, the present invention provides a cutting device comprising:

the driving assembly comprises a driving motor, a driving shaft extending out of the driving motor and a driving piece assembled at the tail end of the driving shaft;

the cutting assembly comprises a cutting disc, an extension shaft and a blade arranged on the cutting disc, and an accommodating groove and a through hole are formed in the top of the cutting disc; and

the flat plate assembly comprises a flat plate and a connecting cover positioned between the cutting disc and the flat plate, and the connecting cover is fixedly connected with the flat plate;

the extension shaft is configured to have one end accommodated in the accommodating groove, the cutting disc and the driving piece fixedly connected with the accommodating groove, and the other end penetrating through the through hole and extending into the connecting cover and movably connected with the connecting cover, the central axis of the extension shaft and the central axis of the driving shaft are located on the same straight line, when the driving motor drives the driving shaft to rotate, the driving piece drives the extension shaft and the cutting disc to synchronously rotate, and the flat plate assembly is kept still.

As a further improvement of the present invention, the flat component further includes a ball bearing and a fixing member, the ball bearing is sleeved outside the extension shaft to movably connect the extension shaft and the connection cover, and the fixing member is configured to be inserted into the extension shaft from the bottom of the extension shaft, so that the extension shaft, the ball bearing and the connection cover are relatively fixed.

As a further improvement of the invention, the flat plate component further comprises a first gasket sleeved on the fixing piece, and when the fixing piece is fixed in the extension shaft, the first gasket is clamped and fixed between the ball bearing and the fixing piece.

As a further improvement of the present invention, the connecting cover is provided with a through hole at the top and a receiving passage which is communicated with the through hole and is coaxially arranged, the diameter of the receiving passage is larger than that of the through hole, the ball bearing is received in the receiving passage, an outer ring of the ball bearing is attached to the inner wall surface of the receiving passage, and the extension shaft passes through the ball bearing.

As a further improvement of the invention, the bottom of the cutting disk is provided with a convex ring, the top of the connecting cover is also provided with a groove surrounding the through hole, when the connecting cover is assembled at the bottom of the cutting disk, the extending shaft passes through the through hole, and the convex ring is accommodated in the groove.

As a further improvement of the invention, the accommodating groove is provided with a hexagonal inner cavity, and the driving piece is also arranged in a hexagonal shape.

As a further improvement of the present invention, the through hole penetrates through a bottom wall of the receiving groove, and the driving member is received in the receiving groove and located on an upper surface of the extension shaft.

As a further improvement of the present invention, the extension shaft is disposed in a T shape, and includes a fixing portion and an extension portion disposed perpendicular to the fixing portion, the fixing portion is accommodated in the accommodating groove and attached to the bottom wall, and the extension portion penetrates through the through hole.

As a further improvement of the present invention, a first locking hole is formed in the bottom wall, a second locking hole is correspondingly formed in the fixing portion, a third locking hole is correspondingly formed in the driving member, and the locking member penetrates through the first locking hole, the second locking hole and the third locking hole to lock and fix the cutting disc, the extension shaft and the driving member.

As a further improvement of the present invention, the bottom wall is further provided with a positioning column, the fixing portion is provided with a slot, and the positioning column passes through the slot, so that the fixing portion is positioned and accommodated in the accommodating groove.

As a further improvement of the present invention, the accommodating groove is provided with a hexagonal inner cavity, and the fixing portion is arranged in a circular shape.

It is also an object of the present invention to provide a lawnmower which can reduce maintenance costs after wear has occurred.

In order to achieve the above object, the present invention provides a lawn mower including a mower body and a cutting device disposed at a bottom of the mower body, the cutting device including:

the extension shaft is configured to have one end accommodated in the accommodating groove, the cutting disc and the driving part fixedly connected with the accommodating groove, the other end penetrates through the through hole and extends into the connecting cover and is movably connected with the connecting cover, the central axis of the extension shaft and the central axis of the driving shaft are located on the same straight line, and when the driving shaft is driven by the driving motor to rotate, the driving part drives the extension shaft and the cutting disc to synchronously rotate, and the flat plate component keeps still.

As a further improvement of the present invention, the connecting cover is provided with a through hole at the top and a receiving passage which is communicated with the through hole and is coaxially arranged, the diameter of the receiving passage is larger than that of the through hole, the ball bearing is received in the receiving passage, an outer ring of the ball bearing is attached to an inner wall surface of the receiving passage, and the extension shaft passes through the ball bearing.

As a further improvement of the invention, the accommodating groove is provided with a hexagonal inner cavity, the driving part is also arranged in a hexagonal shape, and the fixing part is arranged in a circular shape.

The beneficial effects of the invention are: according to the cutting device, the driving part is arranged at the tail end of the driving shaft, the extension shaft is arranged in the cutting disc, and meanwhile, one end of the extension shaft is fixedly connected with the cutting disc and the driving part, and the other end of the extension shaft extends into the connecting cover to be movably connected with the connecting cover, so that when the driving motor drives the driving shaft to rotate, the extension shaft and the cutting disc can be driven by the driving part to synchronously rotate, a blade is enabled to carry out cutting action, and the flat plate component is kept not to rotate. Because the drive shaft passes through the driving piece and extends axle and cutting disc assembly fixed, so when wearing and tearing appear, can directly change and extend axle and driving piece, need not to change the drive shaft, reduced the maintenance cost.

Drawings

Fig. 1 is a perspective view of the mower of the present invention.

Fig. 2 is a cross-sectional view of the mower of fig. 1.

Fig. 3 is a perspective view of the cutting device of fig. 2.

Fig. 4 is a sectional view of the cutting device shown in fig. 3.

Fig. 5 is a partially enlarged view of fig. 4.

Fig. 6 is an exploded view of the cutting device shown in fig. 3.

Fig. 7 is an exploded view of the cutting assembly of fig. 6.

Fig. 8 is a perspective view of the cutting disk of fig. 7.

Fig. 9 is a partially enlarged view of fig. 8.

Fig. 10 is a perspective view of the extension shaft of fig. 7.

Figure 11 is a perspective view of the actuator of figure 7.

Fig. 12 is another angular perspective view of the cutting disk of fig. 8.

Fig. 13 is a partially enlarged view of fig. 12.

Fig. 14 is a perspective view of the connection cover of fig. 7.

Fig. 15 is another angular perspective view of the connection hood of fig. 14.

Reference numerals:

100-a mower, 10-a body, 11-a front traveling wheel and 12-a rear traveling wheel;

20-cutting device, 21-driving component, 211-driving motor, 212-driving shaft, 213-driving component, 2131-third locking hole, 2132-blind hole, 22-cutting component, 221-cutting disk, 2211-containing groove, 2212-bottom wall, 2213-perforation, 2214-avoiding groove, 2215-first locking hole, 2216-positioning column, 2217-convex ring, 222-extending shaft, 2221-fixing part, 2222-extending part, 2223-second locking hole, 2224-slotting, 223-blade, 23-flat plate component, 231-flat plate, 232-connecting cover, 2320-groove, 2321-through hole, 2322-containing channel, 2323-limiting groove, 233-ball bearing, 234-fixing part, 235-first washer, 236-second washer, 237-sealing ring;

30-locking piece, 40-self-tapping screw.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in detail with reference to the accompanying drawings and specific embodiments.

As shown in fig. 1 and 2, the present invention discloses a lawn mower 100, which comprises a mower body 10 and a cutting device 20 disposed at the bottom of the mower body 10, wherein the mower body 10 comprises a front traveling wheel 11 and a rear traveling wheel 12, and the front traveling wheel 11 and the rear traveling wheel 12 not only can drive the lawn mower 100 to move forward, backward and turn, but also can play a role in supporting the lawn mower 100, so as to ensure that the lawn mower 100 can normally travel and perform a cutting action. Since the main improvement of the present invention is the cutting device 20, the detailed structure of the machine body 10 will not be described in detail, and is not limited.

As shown in fig. 3 to 6, the cutting device 20 mainly includes a driving component 21, a cutting component 22 and a flat component 23, wherein the driving component 21 is used for driving the cutting component 22 to rotate so as to perform a mowing action; the plate member 23 serves to protect the cutting member 22. Specifically, the driving assembly 21 includes a driving motor 211, a driving shaft 212 extending from the driving motor 211, and a driving member 213 assembled at the end of the driving shaft 212; the cutting assembly 22 comprises a cutting disc 221, an extension shaft 222 accommodated in the cutting disc 221, and a blade 223 arranged on the cutting disc 221, wherein the top of the cutting disc 221 is provided with an accommodating groove 2211 and a through hole 2213; the plate assembly 23 comprises a plate 231 and a connecting cover 232 positioned between the cutting disc 221 and the plate 231, wherein the connecting cover 232 is fixedly connected with the plate 231. In this embodiment, the driving motor 211 is preferably a driving motor, and the driving shaft 212 is preferably a motor shaft; the cutting disc 221 is disposed in a disc shape, and the blades 223 are disposed at 5 positions and are uniformly distributed at the edge of the cutting disc 221.

The extension shaft 222 is configured to have one end received in the receiving slot 2211 and fixedly connected to the cutting plate 221 and the driving member 213, and another end passing through the through hole 2213 and extending into the connecting cover 232 to be movably connected to the connecting cover 232. Preferably, the cutting disc 221, the extension shaft 222 and the driving member 213 are locked and fixed to each other by a locking member 30, and the central axis of the extension shaft 222 and the central axis of the driving shaft 212 are located on the same straight line, so that when the driving motor 211 drives the driving shaft 212 to rotate, the driving member 213 can drive the extension shaft 222 and the cutting disc 221 to synchronously rotate, so that the blade 223 performs a cutting operation, and at this time, the flat plate assembly 23 remains stationary. Therefore, the cutting device 20 of the present invention uses an independently disposed extension shaft 222 to connect the driving shaft 212 and the cutting disc 221, which not only can reduce the manufacturing cost while achieving the same function, but also can directly replace the extension shaft 222 after the extension shaft 222 and the cutting disc 221 are seriously worn, thereby reducing the maintenance cost.

The following description will describe in detail the connection structure between the driving shaft 212, the cutting disk 221 and the extension shaft 222.

As shown in fig. 8 to 11, a receiving groove 2211, a bottom wall 2212 positioned at the bottom of the receiving groove 2211, and a perforation 2213 formed through the bottom wall 2212 are formed at the top of the cutting plate 221. The extension shaft 222 is T-shaped, one end of the extension shaft is received in the receiving slot 2211, the other end of the extension shaft penetrates through the cutting plate 221 from the through hole 2213, and the driving member 213 is received in the receiving slot 2211 and is located on the upper surface of the extension shaft 222. In other words, the accommodating groove 2211 is provided for the purpose of: providing a housing space for the driving member 213 and the extension shaft 222 while achieving the connection of the driving assembly 10 and the cutting assembly 22.

In order to ensure the connection stability between the driving member 213 and the cutting disc 221, the receiving slot 2211 is provided with a hexagonal inner cavity, and the driving member 213 is also provided with a hexagonal shape, so that when the driving member 213 is assembled and fixed with the cutting disc 221, the driving member 213 is stably received in the receiving slot 2211 by using the mutual attachment and interference of the two hexagons, and then the cutting disc 221 can be driven to rotate synchronously.

In this embodiment, the driving member 213 is a hexagonal nut, and a right angle is formed between two adjacent straight edges; in order to ensure that the driving member 213 can be conveniently and rapidly installed in the accommodating groove 2211, the connecting portions of every two of the six straight edges forming the inner cavity of the accommodating groove 2211 are rounded to form six circular arc-shaped avoiding grooves 2214, so that when the hexagonal driving member 213 is assembled in the accommodating groove 2211, the six right angles of the driving member 213 can be avoided by using the six avoiding grooves 2214, and the problem of difficult assembly is avoided.

Of course, in other embodiments, the inner cavity of the receiving slot 2211 and the outer shape of the driving member 213 may be set to other shapes, as long as the two can perform the mutual matching and interference functions to ensure that the driving member 213 can drive the cutting disc 221 to rotate synchronously, which is not limited herein.

The extension shaft 222 includes a fixing portion 2221 and an extension portion 2222 perpendicular to the fixing portion 2221, the fixing portion 2221 is received in the receiving slot 2211 and attached to the bottom wall 2212, and the extension portion 2222 is protruded from the through hole 2213. In order to further reduce the manufacturing cost and the maintenance cost, the fixing portion 2221 of the extension shaft 222 is configured to be circular, and the diameter of the circle is slightly smaller than the distance between two straight sides of the inner cavity of the receiving slot 2211, so that the circular fixing portion 2221 can be received in the receiving slot 2211.

Because the inner cavities of the receiving slots 2211 are hexagonal, the fixing portions 2221 are circular, and there is no mutual matching and interference between the two, in order to ensure the connection stability between the extension shaft 222 and the driving member 213 and the cutting disc 221, the bottom wall 2212 is provided with a first locking hole 2215, the fixing portions 2221 are correspondingly provided with a second locking hole 2223, the driving member 213 is also provided with a third locking hole 2131, and the first locking hole 2215, the second locking hole 2223 and the third locking hole 2131 are aligned with each other, so that the cutting disc 221, the extension shaft 222 and the driving member 213 can be locked and fixed by passing through the first locking hole 2215, the second locking hole 2223 and the third locking hole 2131 from bottom to top in sequence through the locking members 30. Preferably, the locker 30 is a locking screw.

In addition, since the fixing portion 2221 is circularly disposed, rotation is easy to occur, and the first locking hole 2215, the second locking hole 2223 and the third locking hole 2131 cannot be precisely aligned, in the present invention, a positioning post 2216 protruding into the receiving slot 2211 is further disposed on the bottom wall 2212, and a slot 2224 is correspondingly disposed on the fixing portion 2221, so that the fixing portion 2221 can be positioned in the receiving slot 2211 by the positioning post 2216 passing through the slot 2224. Correspondingly, the driving member 213 is also correspondingly provided with a blind hole 2132 for accommodating the positioning post 2216, so that the cutting disc 221, the extending shaft 222 and the driving member 213 can be positioned with respect to each other. In this embodiment, the first locking holes 2215 are provided with 3, and are uniformly distributed on the bottom wall 2212, and the positioning columns are also provided with 3, and are distributed between two adjacent first locking holes 2215, so that the fixing portion 2221 can be stably attached to the bottom wall 2212.

As shown in fig. 12 to 15 in combination with fig. 5 and 7, the flat plate 231 serves to protect the cutting disc 221 and the blade 223. The bottom of the cutting disc 221 is provided with a downwardly protruding convex ring 2217, the connecting cover 232 is provided with a through hole 2321 at the top and a groove 2320 surrounding the through hole 2321, and the through hole 2321 is coaxially arranged with the through hole 2213. When the connecting cover 232 is assembled to the bottom of the cutting disc 221, the extending shaft 222 passes through the through hole 2321, the protruding ring 2217 is received in the groove 2320, and there is no other interference or fixed connection relationship between the protruding ring 2217 and the groove 2320. Therefore, when the cutting disc 221 rotates, the connecting cover 232 is not driven to rotate.

The connecting cover 232 is further provided with a receiving channel 2322 which is communicated with the through hole 2321 and is coaxially arranged, the diameter of the receiving channel 2322 is larger than that of the through hole 2321, the ball bearing 233 is received in the receiving channel 2322, the outer ring of the ball bearing 233 is attached to the inner wall surface of the receiving channel 2322, the extension shaft 222 penetrates through the ball bearing 233 and is fixed with the inner ring of the ball bearing 233, so that when the extension shaft 222 drives the inner ring of the ball bearing 233 to synchronously rotate, the connecting cover 232 is kept not to rotate. In this embodiment, two ball bearings 233 are disposed and are sleeved outside the extension shaft 222 in an up-down arrangement manner to movably connect the extension shaft 222 and the connection cover 232, wherein the upper ball bearing 233 abuts against the upper surface of the receiving channel 2322, and the lower surface of the lower ball bearing 233 is substantially flush with the lower surface of the extension shaft 222. Of course, the lower surface of the extension shaft 222 may be slightly higher than the lower surface of the ball bearing 233 located below, which is not limited herein.

As shown in fig. 5, 7 and 15, the plate assembly 23 further includes a fixing member 234, a first washer 235 sleeved on the fixing member 234, a second washer 236 received in the receiving channel 2322 and located at the bottom, and a sealing ring 237 for sealing and connecting the second washer 236 to the connecting cover 232, wherein the fixing member 234 is configured to be inserted into and fixed in the extension shaft 222 from the bottom of the extension shaft 222, and the first washer 235 is clamped and fixed between the ball bearing 233 and the fixing member 234, so that the extension shaft 222, the ball bearing 233 and the connecting cover 232 are relatively fixed. Preferably, the diameter of the first washer 235 is equal to or larger than the outer diameter of the inner ring of the ball bearing 233, so that the first washer 235 can be used to assist in supporting the extension shaft 233 and the inner ring of the ball bearing 233; the fixing member 234 is a fixing screw and is screw-fixed to the inner cavity of the extension shaft 222.

The second washer 236 is received at the bottom of the receiving channel 2322, the sealing ring 237 is received in the limiting groove 2323 located below the receiving channel 2322, and the inner diameter of the limiting groove 2323 is larger than the outer diameter of the receiving channel 2322, so that the second washer 236 and the sealing ring 237 can be fixed respectively by mutual extrusion of the second washer 236 and the sealing ring 237, and meanwhile, the outer ring of the ball bearing 233 can be supported, and the waterproof and moistureproof effects can be achieved.

The flat plate 231 and the connection cover 232 are connected by tapping screws 40, and the number of the tapping screws 40 is preferably 3, but not limited thereto.

The working principle of the cutting device 20 is as follows: when the driving motor 211 drives the driving shaft 212 to rotate, the driving member 213 rotates synchronously; meanwhile, the driving member 213 drives the extension shaft 222 and the cutting disc 221 to rotate synchronously, the inner ring of the ball bearing 233 rotates synchronously, the outer ring remains stationary, and thus the connecting cover 232 and the flat plate 231 remain stationary; at this time, the rotation of the cutting disc 221 can be used to drive the blade 223 to rotate synchronously, so as to achieve the mowing action.

In summary, in the cutting device 20 of the present invention, the driving member 213 is disposed at the end of the driving shaft 212, the extension shaft 222 is disposed in the cutting disc 221, and the extension shaft 222 is configured such that one end is fixedly connected to the cutting disc 221 and the driving member 213 via the locking member 30, and the other end is inserted into the connecting cover 232 to be movably connected to the connecting cover 232, so that when the driving motor 211 drives the driving shaft 212 to rotate, the driving member 213 can drive the extension shaft 222 and the cutting disc 221 to synchronously rotate, so as to enable the cutting blade 223 to perform the cutting action, while the plate assembly 23 is kept not to rotate. In addition, because the driving shaft 212 is assembled and fixed with the extension shaft 222 and the cutting disc 221 through the driving member 213, when the abrasion occurs, the extension shaft 222 and the driving member 213 can be directly replaced without replacing the driving shaft 212, thereby reducing the maintenance cost.

Although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the spirit and scope of the present invention.

Claims

1. A cutting device, comprising:

the driving assembly (21) comprises a driving motor (211), a driving shaft (212) extending out of the driving motor (211) and a driving piece (213) assembled at the tail end of the driving shaft (212);

the cutting assembly (22) comprises a cutting disc (221), an extension shaft (222) and a blade (223) arranged on the cutting disc (221), wherein the top of the cutting disc (221) is provided with a containing groove (2211) and a perforation (2213); and

the flat plate assembly (23) comprises a flat plate (231) and a connecting cover (232) positioned between the cutting disc (221) and the flat plate (231), and the connecting cover (232) is fixedly connected with the flat plate (231);

the extension shaft (222) is configured such that one end is accommodated in the accommodating groove (2211) and fixedly connected with the cutting disc (221) and the driving part (213), the other end passes through the through hole (2213) and extends into the connecting cover (232) to be movably connected with the connecting cover (232), the central axis of the extension shaft (222) and the central axis of the driving shaft (212) are located on the same straight line, when the driving motor (211) drives the driving shaft (212) to rotate, the driving part (213) drives the extension shaft (222) and the cutting disc (221) to synchronously rotate, and the flat plate assembly (23) is kept stationary.

2. The cutting device of claim 1, wherein: the flat plate component (23) further comprises a ball bearing (233) and a fixing piece (234), the ball bearing (233) is sleeved on the outer side of the extension shaft (222) to movably connect the extension shaft (222) and the connecting cover (232), and the fixing piece (234) is configured to be inserted into the extension shaft (222) from the bottom of the extension shaft (222), so that the extension shaft (222), the ball bearing (233) and the connecting cover (232) are relatively fixed.

3. The cutting device of claim 2, wherein: the flat plate component (23) further comprises a first gasket (235) sleeved on the fixing piece (234), and when the fixing piece (234) is fixed in the extension shaft (222), the first gasket (235) is clamped and fixed between the ball bearing (233) and the fixing piece (234).

4. The cutting device of claim 2, wherein: the connecting cover (232) is provided with a through hole (2321) located at the top and an accommodating channel (2322) communicated with the through hole (2321) and coaxially arranged, the diameter of the accommodating channel (2322) is larger than that of the through hole (2321), the ball bearing (233) is accommodated in the accommodating channel (2322), the outer ring of the ball bearing (233) is attached to the inner wall surface of the accommodating channel (2322), and the extending shaft (222) penetrates through the ball bearing (233).

5. The cutting device of claim 4, wherein: the bottom of cutting dish (221) is equipped with bulge loop (2217), the top of connecting cover (232) still is equipped with and encircles recess (2320) of through-hole (2321), when connecting cover (232) assemble in the bottom of cutting dish (221), extension axle (222) pass through-hole (2321), bulge loop (2217) accept in recess (2320).

6. The cutting device of claim 1, wherein: the accommodating groove (2211) is provided with a hexagonal inner cavity, and the shape of the driving piece (213) is also hexagonal.

7. The cutting device of claim 1, wherein: the through hole (2213) penetrates through the bottom wall (2212) of the accommodating groove (2211), and the driving piece (213) is accommodated in the accommodating groove (2211) and is positioned on the upper surface of the extension shaft (222).

8. The cutting device of claim 7, wherein: the extension shaft (222) is arranged in a T shape and comprises a fixing portion (2221) and an extension portion (2222) perpendicular to the fixing portion (2221), the fixing portion (2221) is accommodated in the accommodating groove (2211) and attached to the bottom wall (2212), and the extension portion (2222) penetrates out of the through hole (2213).

9. The cutting device of claim 8, wherein: first locking holes (2215) are formed in the bottom wall (2212), second locking holes (2223) are correspondingly formed in the fixing portion (2221), third locking holes (2131) are correspondingly formed in the driving piece (213), and locking pieces (30) penetrate through the first locking holes (2215), the second locking holes (2223) and the third locking holes (2131) to lock and fix the cutting disc (221), the extending shaft (222) and the driving piece (213).

10. The cutting device of claim 8, wherein: the bottom wall (2212) is further provided with a positioning column (2216), a slot (2224) is formed in the fixing portion (2221), and the positioning column (2216) penetrates through the slot (2224) to enable the fixing portion (2221) to be positioned and contained in the containing groove (2211).

11. The cutting device of claim 8, wherein: the accommodating groove (2211) is provided with a hexagonal inner cavity, and the fixing part (2221) is arranged in a circular shape.

12. A lawn mower comprising a machine body (10) and a cutting device (20) arranged at the bottom of the machine body (10), characterized in that the cutting device (20) comprises:

the cutting assembly (22) comprises a cutting disc (221), an extension shaft (222) and a blade (223) arranged on the cutting disc (221), and the top of the cutting disc (221) is provided with a containing groove (2211) and a perforation (2213); and

the extension shaft (222) is configured to have one end contained in the containing groove (2211) and fixedly connected with the cutting disc (221) and the driving part (213), and the other end penetrating through the through hole (2213) and extending into the connecting cover (232) and movably connected with the connecting cover (232), the central axis of the extension shaft (222) and the central axis of the driving shaft (212) are located on the same straight line, when the driving shaft (212) is driven by the driving motor (211) to rotate, the driving part (213) drives the extension shaft (222) and the cutting disc (221) to synchronously rotate, and the flat plate assembly (23) is kept still.

13. The lawnmower of claim 12, wherein: the flat component (23) further comprises a ball bearing (233) and a fixing piece (234), the ball bearing (233) is sleeved on the outer side of the extension shaft (222) to movably connect the extension shaft (222) and the connecting cover (232), and the fixing piece (234) is configured to be inserted into the extension shaft (222) from the bottom of the extension shaft (222) so that the extension shaft (222), the ball bearing (233) and the connecting cover (232) are relatively fixed.

14. The mower of claim 13, wherein: the flat component (23) further comprises a first washer (235) sleeved on the fixing piece (234), and when the fixing piece (234) is fixed in the extension shaft (222), the first washer (235) is clamped and fixed between the ball bearing (233) and the fixing piece (234).

15. The mower of claim 13, wherein: the connecting cover (232) is provided with a through hole (2321) located at the top and an accommodating channel (2322) communicated with the through hole (2321) and coaxially arranged, the diameter of the accommodating channel (2322) is larger than that of the through hole (2321), the ball bearing (233) is accommodated in the accommodating channel (2322), the outer ring of the ball bearing (233) is attached to the inner wall surface of the accommodating channel (2322), and the extending shaft (222) penetrates through the ball bearing (233).

16. The lawnmower of claim 15, wherein: the bottom of the cutting disk (221) is provided with a convex ring (2217), the top of the connecting cover (232) is also provided with a groove (2320) surrounding the through hole (2321), when the connecting cover (232) is assembled at the bottom of the cutting disk (221), the extending shaft (222) penetrates through the through hole (2321), and the convex ring (2217) is accommodated in the groove (2320).

17. The lawnmower of claim 12, wherein: the through hole (2213) penetrates through the bottom wall (2212) of the accommodating groove (2211), and the driving piece (213) is accommodated in the accommodating groove (2211) and is positioned on the upper surface of the extension shaft (222).

18. The lawnmower of claim 17, wherein: the extension shaft (222) is arranged in a T shape and comprises a fixing portion (2221) and an extension portion (2222) perpendicular to the fixing portion (2221), the fixing portion (2221) is accommodated in the accommodating groove (2211) and attached to the bottom wall (2212), and the extension portion (2222) penetrates through the through hole (2213).

19. The mower of claim 18, wherein: first locking holes (2215) are formed in the bottom wall (2212), second locking holes (2223) are correspondingly formed in the fixing portion (2221), third locking holes (2131) are correspondingly formed in the driving piece (213), and locking pieces (30) penetrate through the first locking holes (2215), the second locking holes (2223) and the third locking holes (2131) to lock and fix the cutting disc (221), the extending shaft (222) and the driving piece (213).

20. The mower of claim 18, wherein: the bottom wall (2212) is further provided with a positioning column (2216), a slot (2224) is formed in the fixing portion (2221), and the positioning column (2216) penetrates through the slot (2224) to enable the fixing portion (2221) to be positioned and contained in the containing groove (2211).

21. The mower of claim 18, wherein: the accommodating groove (2211) is provided with a hexagonal inner cavity, the driving piece (213) is also arranged in a hexagonal shape, and the fixing portion (2221) is arranged in a circular shape.