Robotic lawn mower cutting assembly, robotic lawn mower, and method of attaching a lawn mower cutting assembly to a lawn mower

Abstract

A lawn mower cutting assembly (22) includes: a blade carrier device (26) and an anti-skid device (30) axially retained between an axial stop shoulder (60) of a cutting drive shaft (34) and an end member (54) rigidly connected to the cutting drive shaft (34), so that the end member (54) vertically carries the anti-skid device (30) and the blade carrier device (26). The cutting assembly (22) can be attached to a lawn mower, which can be a robotic lawn mower, by positioning the blade carrier device (26) and the anti-skid device (30) on the cutting drive shaft (34); and then axially locking the axial position of the blade carrier device (26) and the anti-skid device (30) relative to the cutting drive shaft (34).

Description

Technical Field

[0001] The present invention relates to a lawnmower cutting assembly, a robotic lawnmower comprising such a lawnmower cutting assembly and a method of attaching a lawnmower cutting assembly to a lawnmower. Background Art

[0002] Since the introduction of robotic lawn mowers to the market, they have greatly facilitated lawn maintenance. However, although robotic lawn mowers help to mow the lawn, like most equipment they still require some care and maintenance, and some costs may be incurred during the service life of the robotic lawn mower. For example, the mowing blades may occasionally need to be re-sharpened or replaced. In addition, robotic lawn mowers consume energy, and keeping low energy consumption can reduce operating costs and / or enable the robotic lawn mower to handle relatively large working areas. WO2015165506A1 discloses an energy-saving robotic lawn mower provided with a cutting assembly, which is configured to carry a mowing blade. The anti-skid plate can keep the friction loss of the engagement between the cutting assembly and the grass at a low level. However, a robotic lawn mower that can further reduce operating costs is needed. This may be particularly important for large facilities that need to handle large areas, large-capacity robotic lawn mowers, and / or facilities that include more than one robotic lawn mower. Summary of the invention

[0003] The object of the present invention is to solve or at least alleviate some or all of the above problems. To this end, a lawn mower cutting assembly suitable for moving one or more mowing blades in a cutting plane to mow grass is provided, the lawn mower cutting assembly comprising: a blade holder device configured to carry one or more mowing blades, the blade holder device configured to rotate around a cutting rotation axis by a cutting drive shaft; an anti-skid plate device, including an anti-skid plate suspended below the blade holder device when in use, the anti-skid plate device being rotatably connected to the blade holder device so that the blade holder device can rotate relative to the anti-skid plate around the cutting rotation axis, wherein the anti-skid plate device and the blade holder device are configured to be axially retained between an axial stop shoulder of the cutting drive shaft and an end member rigidly connected to the cutting drive shaft when in use, so that the end member vertically carries the anti-skid plate device and the blade holder device. Therefore, removing the end member can axially release the blade holder device and the anti-skid plate device, thereby allowing them to be removed in a single operation, which facilitates maintenance. The anti-skid plate may be circular. According to an embodiment, the anti-skid plate may be flat, for example, the anti-skid plate may be cut from a single piece of metal sheet. The cleat may typically be shaped to cover the blade carrier means from below in a manner that the blade carrier means does not substantially engage the grass to be cut, while the blade carried by the blade carrier means extends radially beyond the cleat. The mower cutting assembly may be attached to a wheeled mower, which may be self-propelled or configured to be pushed by an operator. The end member may be removably attached to the cutting drive shaft.

[0004] According to some embodiments, the robotic cutting assembly may be configured to be axially clamped against the axial stop shoulder by the end piece. Thereby a secure and accurate positioning of the anti-skid plate device and the tool holder device may be determined. According to embodiments, the tool holder device and / or any bearing device of the robotic cutting assembly may be configured to be vertically clamped between the end piece and the axial stop shoulder, while the anti-skid plate device may be axially locked to the tool holder device by, for example, the bearing device.

[0005] According to some embodiments, the end piece may be concentric with the cutting rotation axis. Such an embodiment is particularly suitable for devices comprising only one end piece.

[0006] According to some embodiments, the tool holder device may have a keyed interface to rotatably lock the tool holder device to the cutting drive shaft. The keyed interface may include axially facing teeth that mesh with matching axially facing teeth of the cutting drive shaft, for example in a Hirth-type engagement. Alternatively or in addition, the keyed interface may include radially facing teeth, such as splines. The keyed interface may have a functionally and / or geometrically consistent profile along the axis of rotation, thereby enabling the axial position of the tool holder device on the cutting drive shaft to be adjusted while rotatably locking the tool holder device to the cutting drive shaft.

[0007] According to some embodiments, the blade holder assembly may include a shaft socket portion configured to receive a cutting drive shaft.

[0008] According to some embodiments, the shaft socket portion may have a cross-section shaped to mate with a D-shaped cutting drive shaft.

[0009] According to some embodiments, the shaft socket portion may include an axially downwardly tapered alignment section that can radially align the blade holder device with the cutting drive shaft when the blade holder device is pressed upward toward the cutting drive shaft.

[0010] According to some embodiments, the anti-skid device may be rotatably connected to the blade holder device via a bearing device, which includes at least one bearing having an inner ring rotatably fixed to the cutting drive shaft and an outer ring rotatably fixed to the anti-skid device.

[0011] According to some embodiments, the inner ring of the bearing may be clamped towards the axial stop shoulder by an end piece. The inner ring of the bearing may be clamped directly adjacent to the axial stop shoulder or may be clamped against the axial stop shoulder by another axially rigid structure such as a tool holder arrangement. The bearing arrangement may comprise two coaxial bearings separated along the cutting rotation axis. The two coaxial bearings may be axially separated by a support sleeve.

[0012] According to some embodiments, the end piece may axially abut the bearing arrangement, and the bearing arrangement may axially abut the tool holder arrangement.

[0013] According to some embodiments, the anti-skid plate device may include a bearing housing. The anti-skid plate may be integral with the bearing housing. Alternatively, the anti-skid plate may be fixedly attached to the bearing housing, such as by bolts.

[0014] According to some embodiments, the cleat device may include a cleat clamping device including a lower cleat clamping element and an upper cleat clamping element, the cleat being clamped between the cleat clamping elements.

[0015] According to some embodiments, the bearing housing may be integrally formed with the lower cleat clamping element.

[0016] According to some embodiments, the clamping bolt may be screwed into the lower cleat clamping element from above. This arrangement protects the clamping bolt from dirt and reduces the risk of the lawn mower cutting assembly being disassembled incorrectly. The clamping bolt may pass through the upper cleat clamping element to engage with the lower cleat clamping element. Alternatively, the bolt head of the clamping bolt itself may form the upper cleat clamping element.

[0017] According to some embodiments, at least one of the lower cleat clamping element and the upper cleat clamping element may define an end piece housing, and the lawn mower cutting assembly may further comprise an end piece cover movable between a closed position, in which the end piece cover covers the underside of the end piece housing, and an open position, in which the end piece cover exposes the end piece for access from below. Thus, the end piece may be protected from dirt and still accessible through the end piece cover if it is necessary to remove or operate the end piece. The end piece may be accommodated in a housing like the housing of the bearing defined above. Thus, the end piece housing may also be a bearing housing.

[0018] According to some embodiments, the end piece cover may include a bayonet joint for connecting to a matching bayonet joint of the end piece housing, wherein a tangential wall of the end piece housing tangential to the cutting rotation axis is provided with at least one anti-skid plate access aperture, and the anti-skid plate may include a central aperture provided with at least one support protrusion extending radially inwardly and penetrating the anti-skid plate access aperture, wherein the bayonet joint of the end piece cover is configured to be axially supported by the support protrusion when the end piece cover is in the closed position. Thus, the anti-skid plate will form part of the bayonet joint of the end piece housing. It may be preferred to make the anti-skid plate from a relatively strong material such as metal (e.g., aluminum sheet). Due to the presence of the support protrusion, the end piece housing does not need to be made of an equally strong material. According to embodiments, the wall of the end piece housing may have a plurality of anti-skid plate access apertures, and the anti-skid plate may include several support protrusions extending radially inwardly penetrating the corresponding anti-skid plate access apertures.

[0019] According to some embodiments, the upper cleat clamping element may include a cover protrusion configured to abut and cover at least a portion of an upper face of the support protrusion. Thus, the bayonet engagement of the end piece cover may engage with a surface of the cover protrusion rather than a surface of the support protrusion. This may reduce wear on the bayonet engagement of the end piece cover.

[0020] According to some embodiments, the end piece cover may be connected to the cleat device by a flexible strap when in the open position.

[0021] According to some embodiments, the axial position of the end piece relative to the cutting drive shaft can be reconfigured to enable the end piece to clamp the anti-slip device and the blade holder device against the axial stop shoulder. The axial position of the end piece can be reconfigured by rotating the end piece threadedly engaged with the cutting drive shaft.

[0022] According to some embodiments, the end piece may be threadably engaged with the cutting drive shaft.

[0023] According to some embodiments, the end piece may be configured to be axially retained to the cutting drive shaft by a bolt configured to engage with an internal thread of the cutting drive shaft. The end piece may be formed by a bolt head integrally formed with the bolt. In an alternative embodiment, the cutting drive shaft may be provided with an external thread, and the end piece may be configured as a nut provided with an internal thread matching the external thread of the cutting drive shaft.

[0024] According to some embodiments, the tool holder device may have an internal thread, and the bolt may be configured as a non-lost bolt having: a bolt head; a threaded section matching the internal thread of the tool holder device; and a reduced width section located between the bolt head and the threaded section, the radial width of the reduced width section being smaller than the radial width of the threaded section. Therefore, after the tool holder device and the anti-skid plate device are removed from the cutting drive shaft, the tool holder device can still be attached to the anti-skid plate device. The threaded section may be configured to match each of the internal thread of the cutting drive shaft and the internal thread of the tool holder device.

[0025] According to a second aspect, some or all of the above problems are solved or at least alleviated by a lawn mower cutting assembly adapted to move one or more mowing blades in a cutting plane to mow grass, and the lawn mower cutting assembly comprises: a blade carrier device configured to carry one or more mowing blades, the blade carrier device configured to rotate about a cutting rotation axis by a cutting drive shaft; an anti-skid plate device, including an anti-skid plate suspended below the blade carrier device when in use, the anti-skid plate device being rotatably connected to the blade carrier device so that the blade carrier device can rotate relative to the anti-skid plate about the cutting rotation axis, wherein the anti-skid plate device and the blade carrier device are configured to be axially retained to the cutting drive shaft by a single fastener. This arrangement facilitates removal of the blade carrier device for maintenance.

[0026] According to a third embodiment, some or all of the above problems are solved or at least alleviated by a lawn mower cutting assembly adapted to move one or more mowing blades in a cutting plane to mow grass, and the lawn mower cutting assembly comprises: a blade carrier device configured to carry one or more mowing blades, the blade carrier device configured to rotate around a cutting rotation axis through a cutting drive shaft; an anti-skid plate device, comprising an anti-skid plate suspended below the blade carrier device when in use, the anti-skid plate device being rotatable relative to the blade carrier device via a bearing so that the blade carrier device can rotate relative to the anti-skid plate around the cutting rotation axis, the bearing being arranged in a bearing housing, wherein the anti-skid plate device comprises an anti-skid plate clamping device, the anti-skid plate clamping device comprising a lower anti-skid plate clamping element and an upper anti-skid plate clamping element, the anti-skid plate being clamped between these anti-skid plate clamping elements, wherein the bearing housing is integrally formed with the lower anti-skid plate clamping element. This arrangement reduces the required height of the lawn mower cutting assembly, thereby enabling the overall height of the lawn mower to be reduced.

[0027] According to a fourth embodiment, some or all of the above problems are solved or at least alleviated by a lawn mower cutting assembly adapted to move one or more mowing blades in a cutting plane to mow grass, and the lawn mower cutting assembly comprises: a blade carrier device configured to carry one or more mowing blades, the blade carrier device configured to rotate around a cutting rotation axis by a cutting drive shaft; an anti-skid plate device, including an anti-skid plate suspended below the blade carrier device when in use, the anti-skid plate device being rotatably connected to the blade carrier device so that the blade carrier device can rotate relative to the anti-skid plate around the cutting rotation axis, wherein the anti-skid plate device and the blade carrier device can be axially held together by a non-lost bolt. This arrangement facilitates the operation of the lawn mower cutting assembly, particularly when a plurality of cutting assemblies are put into use for a group of multiple lawn mowers. The non-lost bolt may be configured to engage with an internal thread of a cutting drive shaft. The non-lost bolt may have: a bolt head; a threaded section matching an internal thread of at least one of the blade carrier device and the anti-skid plate device; and a reduced width section located between the bolt head and the threaded section, the radial width of the reduced width section being less than the radial width of the threaded section.

[0028] According to a fifth embodiment, some or all of the above problems are solved or at least alleviated by a lawn mower cutting assembly adapted to move one or more mowing blades in a cutting plane to mow grass, and the lawn mower cutting assembly comprises: a blade carrier device configured to carry one or more mowing blades, the blade carrier device configured to rotate around a cutting rotation axis by a cutting drive shaft; an anti-skid plate device, comprising an anti-skid plate suspended below the blade carrier device when in use, the anti-skid plate device being rotatable relative to the blade carrier device via a bearing so that the blade carrier device can rotate relative to the anti-skid plate around the cutting rotation axis, the bearing being arranged in a bearing housing; and a bearing housing cover being movable between a closed position and an open position, in which the bearing housing cover covers the lower side of the bearing housing, and in which the bearing housing cover exposes the bearing housing for access from below, wherein the bearing housing cover is configured to be axially supported by an edge of the anti-skid plate when in the closed position. For example, the anti-skid plate may have a central aperture defining an inner anti-skid plate edge, and the bearing housing cover may engage with the central aperture.

[0029] According to a sixth embodiment, some or all of the above problems are solved or at least alleviated by a lawn mower cutting assembly suitable for moving one or more mowing blades in a cutting plane to mow grass, and the lawn mower cutting assembly comprises: a blade holder device, configured to carry one or more mowing blades, the blade holder device being configured to rotate around a cutting rotation axis through a cutting drive shaft; an anti-skid plate device, comprising an anti-skid plate suspended below the blade holder device when in use, the anti-skid plate device being rotatable relative to the blade holder device via a bearing so that the blade holder device can rotate relative to the anti-skid plate around the cutting rotation axis, The bearing may be arranged in a bearing housing; and a bearing housing cover movable between a closed position, in which the bearing housing cover covers the underside of the bearing housing, and an open position, in which the bearing housing cover exposes the bearing housing for access from below, wherein the cleat device comprises a cleat clamping device, the cleat clamping device comprising a lower cleat clamping element and an upper cleat clamping element, the cleat being clamped between these cleat clamping elements, wherein the cleat clamping elements are configured to clamp the cleat between them when the bearing housing cover is in the open position. Therefore, removing the bearing housing cover does not release the cleat from the cleat clamping device. This facilitates removal and maintenance of the lawn mower cutting assembly, for example for replacing a lawn mower blade.

[0030] According to a seventh embodiment, some or all of the above problems are solved or at least alleviated by a robotic lawn mower comprising a lawn mower cutting assembly as defined above.The robotic lawn mower may be a high powered lawn mower comprising a plurality of lawn mower cutting assemblies as defined above.

[0031] According to an eighth embodiment, some or all of the above problems are solved or at least alleviated by a method of attaching a lawn mower cutting assembly to a lawn mower, the method comprising: positioning a blade carrier device and an anti-skid plate device on a cutting drive shaft; and subsequently, axially locking the axial position of the blade carrier device and the anti-skid plate device relative to the cutting drive shaft.

[0032] According to an embodiment, the blade holder device and the anti-skid device can be positioned on the cutting drive shaft in a single operation. The blade holder device and the anti-skid device can be axially locked to the cutting drive shaft using a single fastener.

[0033] It should be noted that embodiments of the present invention can be described by all possible combinations of the features listed in the claims. In addition, it should be understood that the various embodiments of the lawn mower cutting assembly described in the first, second, third, fourth, fifth and sixth aspects can be combined with each other, and can be combined with the method defined in the eighth aspect of the present invention, and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The above objects and other objects, features and advantages of the present invention will be better understood through the following illustrative and non-limiting detailed description of preferred embodiments of the present invention with reference to the accompanying drawings, in which the same reference numerals will be used for similar elements, and in the accompanying drawings:

[0035] Figure 1 is a perspective view of a robotic lawn mower system including a robotic lawn mower;

[0036] Figure 2 Observed from below Figure 1 A stereoscopic image of a robotic lawn mower in;

[0037] Figure 3 Observed from below Figure 1 and Figure 2 A perspective view of a first embodiment of a lawn mower cutting assembly and a cutting drive assembly of a robotic lawn mower;

[0038] Figure 4 Shows Figure 3 A section of a lawn mower cutting assembly and a cutting drive assembly in a separated state, the section being taken along a vertical plane coinciding with the cutting rotation axis;

[0039] Figure 5 yes Figure 4 an enlarged view of a portion of a cutting assembly in;

[0040] Figure 6 Observed from above Figures 3 to 5 An exploded perspective view of the cutting assembly in FIG.

[0041] Figure 7 Observed from below Figures 3 to 6 An exploded perspective view of the cutting assembly in FIG.

[0042] Fig. 8A Shows Figure 4 A section of a lawn mower cutting assembly and a cutting drive assembly in a connected state, the section also being taken along a vertical plane coinciding with the cutting rotation axis, wherein the lawn mower cutting assembly is shown with the end piece housing in a closed position;

[0043] Figure 8B is corresponding to Fig. 8A an enlarged view of a portion of , wherein the lawn mower cutting assembly is shown with the end piece housing in an open position;

[0044] Figure 8C is corresponding to Figure 8B and showing an alternative position of the clamping bolt;

[0045] Fig. 9is a flow chart illustrating a method of attaching a lawn mower cutting assembly to a lawn mower;

[0046] Fig.10 is a perspective view of a cutting drive shaft, a portion of a tool holder assembly, and an end member according to a second embodiment;

[0047] Fig.11 is a perspective view of a cutting drive shaft, a portion of a blade holder assembly, and an end piece according to a third embodiment.

[0048] All figures are schematic, not to scale, and generally only show parts which are necessary in order to elucidate the embodiments, while other parts may be ignored. DETAILED DESCRIPTION

[0049] Figure 1 Schematically shown is an overview of a robotic lawn mower system 10 configured to mow lawns in a working area 12, such as a garden, a park, a football field or a golf course, which is defined by a working area boundary 13. The robotic lawn mower system 10 comprises a self-propelled robotic lawn mower 14 and a battery charging station 16. In the illustrated embodiment, the robotic lawn mower 14 is a multi-chassis mower and comprises a drive unit 14a and a cutting deck 14b connected to each other by a coupling device 14c.

[0050] Figure 2 The robot lawn mower 14 is shown viewed from below. As apparent from the bottom view, the drive unit 14a includes a pair of drive wheels 18 that are driven by respective wheel motors (not shown) to propel the robot lawn mower 14 to travel over the work area 12 ( Figure 1 ). The drive wheel 18 is arranged to rotate about a drive wheel axis A, which is perpendicular to the main propulsion direction D of the robotic mower 14. The cutting deck 14b includes a set of casters 20, which are configured to roll on the ground to support the cutting deck 14b during operation of the mower 14. In the illustrated embodiment, the robotic mower 14 is a high-productivity robotic mower provided with a plurality of cutting assemblies 22a, 22b, 22c, which can be distributed along the width W of the cutting deck to enable widening the cutting width. Each cutting assembly 22a-c holds a set of mowing blades 24 and is configured to move when in Figure 1 When in the normal operating position, the corresponding set of mowing blades 24 rotates in a substantially horizontal cutting plane to cut grass. The cutting assemblies 22a-22c can be substantially identical, so for the sake of simplicity, only one cutting assembly 22 ( Figure 3 ), and it is worth noting that all details of the cutting assembly 22 are applicable to Figure 2 Each of the three cutting assemblies 22a-c.

[0051] Figure 3 The robot lawn mower 14 is shown in FIG. Figure 1 The lawn mower cutting assembly 22 is viewed obliquely from below when in the normal working posture. Figure 3 Also shown is a portion of the cutting drive assembly 23, including a housing of a cutting drive motor 28, which holds and drives the cutting assembly 22. The cutting assembly 22 includes a carrier device 26, which carries a plurality of mowing blades 24. The carrier device 26 is operatively connected to the cutting drive motor 28 via a drive shaft (not shown) so that the cutting drive motor 28 can transmit rotational power to the carrier device 26 to rotate the mowing blades 24 around a common cutting rotation axis C. Therefore, these mowing blades 24 rotate in a common cutting plane perpendicular to the cutting rotation axis C. The cutting assembly 22 also includes an anti-skid plate device 30, which includes an anti-skid plate 32 suspended below the carrier device. The anti-skid plate device 30 is rotatably connected to the carrier device 26 so that the carrier device 26 can rotate around the cutting rotation axis C without rotating the anti-skid plate 32. Therefore, the anti-skid plate 32 can protect the rotating carrier device 26 from excessive engagement with the grass (not shown), so that the friction between the grass and the carrier device 26 is kept at a low level. Typically, the cleat 32 may be made of a relatively strong material such as sheet metal.

[0052] Figure 4 A vertical cross section of the cutting drive assembly 23 and the cutting assembly 22 is shown, wherein the cutting assembly 22 is shown separated from the cutting drive assembly 23. The tapered end of the cutting drive shaft 34 rotated by the cutting drive motor 28 is configured to be inserted into a similar tapered drive shaft slot portion 36 of the tool holder device 26 and attached to the drive shaft slot portion by an axle connecting bolt 38 concentric with the cutting rotation axis C. Figure 5 As can be better seen in the enlarged view of FIG. 3 , when the blade holder assembly 26 is pressed upward toward the cutting drive shaft 34, the tapered section of the drive shaft slot portion 36 radially aligns the blade holder assembly 26 with the cutting drive shaft 34, thereby operating as an alignment section 61. Referring again to FIG. Figure 4 The cutter carrier device 26 includes a hub 26a and a blade disc 26b, which are rigidly connected to each other by bolts 27. The mowing blade 24 is pivotally attached along the radial periphery of the cutter carrier device 26 by blade attachment bolts 29, which enables the blade 24 to rotate about a blade pivot axis K defined by the corresponding blade attachment bolts 29. Each of the cutting rotation axis C and the blade pivot axis K is substantially perpendicular to the cutting plane P. Referring back to Figure 3 The blade attachment bolts 29 are accessible through holes 31 in the anti-slip plate 32 to replace the corresponding blade 24.

[0053] Continue to refer Figure 4The lower surface of the cutting drive assembly 23 and the upper surface of the tool holder device 26 are both provided with an axial extension structure 40 coaxial with the cutting rotation axis C. These axial extension structures are configured to engage with each other to form a labyrinth seal to prevent dirt from entering the joint between the cutting drive shaft 34 and the drive shaft slot portion 36.

[0054] Reference now Figure 5 , showing Figure 4 In the enlarged portion of the figure, the anti-skid device 30 also includes an anti-skid clamping device 42, which includes a lower anti-skid clamping element 42a and an upper anti-skid clamping element 42b that clamp the anti-skid 32 between them. The anti-skid clamping elements 42a, 42b are fastened together by a clamping bolt 44, the bolt head of which is accessible from below. In another alternative, the head of the clamping bolt 44 is accessible from above, which can guide the disassembly of the cutting assembly 22 in a simpler way, which will be apparent below. The anti-skid device 30 can be rotatably connected to the tool holder device 26 by a bearing device 46, which includes an upper bearing 46a and a lower bearing 46b, which are axially separated by an axial support sleeve 48. Each of the bearings 46a, 46b has a corresponding inner ring 50a and a corresponding outer ring 50b, the inner ring being rotatably fixed to the tool holder device 26 and therefore to the cutting drive shaft 34, and the outer ring being rotatably fixed to the anti-skid device 30. The bearings 46a, 46b are arranged in a cylindrical bearing housing 52 which is formed integrally with the lower cleat clamping element 42a.

[0055] Figure 5 Also shown in more detail is the bolt engaging portion 53 of the cutting drive shaft 34, which is provided with an internal thread 49 for engaging with an external thread of the threaded section 53 of the shaft connecting bolt 38. Figure 1) When the anti-skid plate device 30 and the knife holder device 26 are only attached to the cutting drive shaft 34 and are attached only by the shaft connecting bolt 38. The shaft connecting bolt 38 has a bolt head 54, which operates as an end member that axially abuts against and vertically carries the inner ring 50a of the lower bearing 46b of the bearing device 46. The inner ring 50a of the lower bearing 46b axially abuts against and vertically carries the axial support sleeve 48, which in turn axially abuts against and vertically carries the inner ring 50a of the upper bearing 46a. The inner ring 50a of the upper bearing 46a axially abuts against and vertically carries the axial support shoulder 56 of the knife holder device 26, while the anti-skid plate device 30 is vertically carried by the outer ring 50b of the lower bearing 46b through the lower axial support shoulder 58 of the bearing housing 52. Thus, the bolt head 54 vertically carries the bearing device 46, which vertically carries the anti-skid device 30 and the tool holder device 26 that can be in a rotational relationship with each other. The tapered end of the cutting drive shaft 34 forms an upper axial stop shoulder 60 for the tool holder device 26 when connected to the drive shaft slot portion 36 of the tool holder device 26. Thus, the anti-skid device 30, the tool holder device 26 and the bearing device 46 are axially retained between the axial stop shoulder 60 of the cutting drive shaft 34 and the end member formed by the bolt head 54. If the shaft connection bolt 38 is firmly tightened to the cutting drive shaft 34, the inner ring 50a of the bearing device 46 and the tool holder device 26 are firmly clamped to the cutting drive shaft 34, thereby forming a completely rigid connection with the cutting drive shaft. The lower part of the bearing housing 52 also receives the bolt head 54, so that the lower part of the bearing housing 52 defines the end member housing 55. The end member housing 55 is provided with an end member cover 62, which can be in a closed position (such as Figure 5 shown) and the open position ( Figure 8B ), in the closed position the end piece cover covers the underside of the end piece housing 55, and in the open position the end piece cover exposes the bolt heads 54 for access from below. Obviously, the end piece cover 62 also operates as a bearing housing cover.

[0056] Similar to the cutting drive shaft 34, the blade holder device 26 also has an internal thread 57 that matches the external thread of the threaded section 51 of the shaft connecting bolt 38. The shaft connecting bolt 38 also has a reduced width section 59 extending between the bolt head 54 and the threaded section 51. The radial width of the reduced width section 59 of the shaft connecting bolt 38 is less than the radial width of the internal thread 57 of the blade holder device 26, and the axial length of the reduced width section exceeds the axial length of the internal thread 57 of the blade holder device 26. Therefore, the threaded section 51 of the bolt can be screwed through the internal thread 57 of the blade holder device 26 to become a non-lost bolt retained to the blade holder device 26 and still be attached to the cutting drive shaft 34. When in the non-lost position, the shaft connecting bolt 38 can still hold the blade holder device 26 and the anti-skid plate device 30 together in the event that they are removed from the cutting drive shaft 34.

[0057] Figure 6 is an exploded view of the lawn mower cutting assembly 22 viewed obliquely from above, and Figure 7 is an exploded view of the lawn mower cutting assembly 22 viewed obliquely from below. The cleat 32 has a central aperture 64 defined by an inner cleat edge 65 and a support protrusion 66 of the cleat 30 extending radially toward the center of the central aperture 64. The tangential wall 68 of the end piece housing 55 is provided with three cleat access apertures 70 adapted to receive the support protrusion 66 so that the support protrusion 66 can extend into the end piece housing 55. The upper cleat clamping element 42b is provided with a cover protrusion 72 coinciding with the support protrusion 66 so that when the cleat 30 is clamped between the clamping elements 42a, 42b, the cover protrusion 72 can also extend into the end piece housing 55 to cover the upper face of the support protrusion 66.

[0058] The end piece cover 62 includes a cylindrical body 73 provided with an external bayonet joint 74, which is configured to engage with the support protrusion and cover protrusion 66, 72 extending into the end piece housing when inserted into the end piece housing 55 and rotated about the cutting rotation axis C. The anti-skid plate 32 including the support protrusion 66 can be made of, for example, a metal plate (such as an aluminum plate), which can allow the support protrusion 66 to have a certain elasticity in the direction of the cutting rotation axis C, thereby generating additional axial offset to improve the locking of the bayonet joint 74. The rubber seal 76 configured as an O-ring forms a tight seal between the end piece cover 62 and the end piece housing 55, and also generates a further axial offset to lock the bayonet joint 74. From Figure 5 As can be clearly seen in FIG. 6 , the rubber seal 76 is arranged inside the cylindrical body 73 of the end piece cover 62 .

[0059] The end piece cover 62 is functionally independent of the clamping of the cleat 32 between the upper and lower cleat clamping elements 42b, 42a. Thus, the cleat clamping elements 42b, 42a clamp the cleat 32 therebetween regardless of whether the end piece cover 62 is in the open position or the closed position, so that removal of the end piece cover 62 does not cause the cleat 32 to loosen from the cleat clamping device 42. Figure 7 As can be seen from the view of FIG. 6 , the lower face of the end piece cover 62 is provided with a wrench engagement portion 77. As shown, the wrench engagement portion 77 can be shaped to match a hexagonal socket wrench.

[0060] The end piece cover 62 is connected to the cleat device 30 by a flexible band 78. A first end of the flexible band 78 is provided with a first ring 80 configured to surround the cylindrical body 73 of the end piece cover 62, and a second end of the flexible band 78 is provided with a second ring 82 configured to be attached to the cleat device 30. For example, the second ring 82 can extend through the cleat aperture 70 to be clamped between the cleat clamping elements 42a, 42b or attached to the upper cleat clamping element 42b by, for example, bolts (not shown).

[0061] Figure 7 It is also shown that the mowing blade 24 is rotatably connected to the blade disc 26b so as to be rotatable about the corresponding blade rotation axis K. A cylindrical outer hub 84 formed integrally with the blade disc 26b extends axially along the bearing housing 52 and defines a labyrinth seal with the bearing housing 52 to protect the bearings 46a, 46b from dirt entering from the axial direction. Figure 5 This can be better seen in the cross section.

[0062] Fig. 8A The cutting drive shaft 34 is connected to the cutting table 14b ( Figure 2 ) The lawn mower cutting assembly 22. When connected, the blade carriage assembly 26 and the anti-skid plate assembly 30 are axially held to the cutting drive shaft 34 by only a single fastener, such as only the shaft connecting bolt 38.

[0063] Corresponds to Fig. 8A The area indicated by the dashed rectangle Figure 8B The enlarged view of FIG. 5 shows the end piece cover 62 in the open position, in which the end piece cover 62 is rotated about the cutting rotation axis C to release the bayonet joint 74 from the end piece housing 55. Therefore, the end piece cover 62 is attached to the end piece housing 55 only by the flexible band 78.

[0064] Figure 8C The enlarged view corresponds to Figure 8BThe area shown in the dashed rectangle shows an alternative embodiment of the clamping device, according to which the anti-slip plate clamping elements 42a, 42b are clamped together by a clamping bolt 144, which has been screwed into the clamping elements 42a, 42b from above.

[0065] Fig. 9 The flowchart of the lawn mower cutting assembly 22 ( Figure 4 ) is attached to the lawn mower 14 ( Figure 1 ) method. Figure 5 The method comprises:

[0066] Step 901: Position the knife holder device 26 and the anti-skid plate device 30 on the cutting drive shaft 34;

[0067] Then, step 902 : axially locking the axial positions of the blade holder device 26 and the anti-skid plate device 30 relative to the cutting drive shaft 34 .

[0068] Fig.10 The lower end of the cutting drive shaft and the lawn mower cutting assembly 22 ( Figure 3 ) of some parts. The second embodiment can be Fig.10 In addition to the components shown in Figure 4 According to the second embodiment, the engagement between the cutting drive shaft 134 and the tool holder assembly 126 can be a keyed engagement, which is represented here by the hub portion 126a of the tool holder assembly 126. In the exemplary example, the keyed engagement is defined by a D-shaped cross-section of the cutting drive shaft 134 that engages with a D-shaped drive shaft slot portion 136 in the tool holder assembly 126. In contrast, in Figure 4 In the first embodiment, the cutter head assembly 26 is rigidly attached to the cutting drive shaft 34 only by the clamping force from the shaft connecting bolt 38, while in Fig.10 In the second embodiment, the keyed joint rotatably interlocks the cutting drive shaft 134 and the blade holder assembly 126 .

[0069] The end piece according to the second embodiment is configured as a clamp 154 ​​which is radially clamped to the flat side 188 of the D-shaped cutting drive shaft 134 by means of an end piece clamping bolt 190. Therefore, the clamp 154 ​​does not generate an axial clamping pressure, and in fact, the tool holder device 126 and the anti-skid plate device 30 ( Figure 4 ) can float axially along the cutting drive shaft 134. The upper axial end of the D-shaped cross-section of the cutting drive shaft 134 defines a space for the blade holder assembly 126 and the anti-skid plate assembly 30 ( Figure 4 )'s upper axial stop shoulder 160 so that the anti-skid plate device 30 and the tool holder device 126 are axially retained between the end member 154 and the axial stop shoulder 160.

[0070] Fig.11 A robot cutting assembly 22 ( Figure 3 ) of the lower end of the cutting drive shaft. The third embodiment may be Fig.11 In addition to the components shown in Figure 4 According to the third embodiment, the joint between the cutting drive shaft 234 and the tool holder device 226 can be keyed by the spline 294 in the drive shaft slot portion 236 and on the cutting drive shaft 234, and the joint is represented by the hub portion 226a of the tool holder device 226. The cutting drive shaft 234 can be provided with an external thread 249, and the end piece can be provided with a matching internal thread, and the end piece is configured as a shaft connecting nut 254 here. The radial extension 260 of the cutting drive shaft 234 can provide a connection between the tool holder device 226 and the anti-skid plate device 30 ( Figure 4 ) of the upper axial end stop. The shaft connecting nut 254 and the bearing assembly 46 ( Figure 5 ) is provided with a gasket 292 therebetween.

[0071] The invention has been mainly described above with reference to a few embodiments. However, as will be readily appreciated by a person skilled in the art, other embodiments than those disclosed above are equally feasible within the scope of the invention, as defined by the appended patent claims. For example, the cutting drive shaft need not be elongated or have a circular cross-section. Nor does it need to be formed as a single piece; similar to the tool holder arrangement, the cutting drive shaft may consist of several parts attached to one another. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality.

Claims

1. A lawn mower cutting assembly (22) adapted to move one or more mowing blades (24) in a cutting plane (P) to cut grass to trim a lawn, the mower cutting assembly comprising: A blade carrier device (26; 126; 226) is configured to carry the one or more mowing blades (24), wherein the blade carrier device (26; 126; 226) is configured to drive a cutting drive shaft (34; 134; 234) rotates about a cutting rotation axis (C); The anti-skid plate device (30) comprises an anti-skid plate (32) suspended below the tool holder device when in use, and the anti-skid plate device (30) is rotatably connected to the tool holder device (26; 126; 226), so that the tool holder device (26; 126; 226) can rotate relative to the anti-slip plate (32) around the cutting rotation axis (C), characterized in that The anti-skid plate device (30) and the blade holder device (26; 126; 226) are configured to axially retain the axial stop shoulder (60; 160; 260) of the cutting drive shaft (34; 134; 234) and the cutting drive shaft (34; 134; 234) rigidly connected to the cutting drive shaft (34; 134; 234) when in use. 134; 234) between the end members (54; 154; 254), so that the end members (54; 154; 254) vertically supports the anti-skid plate device (30) and the tool holder device (26; 126；226)。 2. The lawn mower cutting assembly (22) of claim 1, wherein: The lawn mower cutting assembly is configured to be axially clamped against the axial stop shoulder (60; 260) by the end piece (54; 254).

3. The lawn mower cutting assembly (22) of claim 1, wherein: The end member (54; 154; 254) is concentric with the cutting rotation axis (C).

4. The lawn mower cutting assembly (22) of claim 1, wherein: The blade carrier assembly (126; 226) has a keyed engagement portion to rotationally lock the blade carrier assembly (126; 226) to the cutting drive shaft (134; 234).

5. The lawn mower cutting assembly (22) of claim 1, wherein: The tool holder device (26; 126; 226) includes a shaft slot portion (36; 136; 236) configured to receive the cutting drive shaft (34; 134; 234).

6. The lawn mower cutting assembly (22) of claim 5, wherein: The shaft socket portion (136) has a cross section shaped to match the D-shaped cutting drive shaft (134).

7. The lawn mower cutting assembly (22) of claim 5, wherein: The shaft socket portion (36) includes an alignment section (61) that tapers axially downward.

8. The lawn mower cutting assembly (22) of claim 1, wherein: The anti-skid plate device (30) is rotatably connected to the tool holder device (26) via a bearing device (46); 126; 226), the bearing device includes: at least one bearing (46a; 46b) having an inner ring (50a) rotationally fixed to the cutting drive shaft (34; 134; 234) and an outer ring (50b) rotationally fixed to the anti-skid plate device (30).

9. The lawn mower cutting assembly (22) of claim 8, wherein: The bearing (46a; 46b) is clamped towards the axial stop shoulder (60; 260) by the end piece (54; 254).

10. The lawn mower cutting assembly (22) of claim 8, wherein: The end member (54; 254) is axially adjacent to the bearing device (46), and the bearing device (46) is axially adjacent to the tool holder device (26; 226).

11. The lawn mower cutting assembly (22) of claim 1, wherein: The anti-skid plate device (30) includes a bearing housing (52).

12. The lawn mower cutting assembly (22) of claim 11, wherein: The anti-skid plate device (30) comprises an anti-skid plate clamping device, which comprises a lower anti-skid plate clamping element (42a) and an upper anti-skid plate clamping element (42b), and the anti-skid plate (32) is clamped between these anti-skid plate clamping elements (42a, 42b).

13. The lawn mower cutting assembly (22) of claim 12, wherein: The bearing housing (52) is integrally formed with the lower cleat clamping element (42a).

14. The lawn mower cutting assembly (22) of claim 12, wherein: The clamping bolt (144) is screwed from above into the lower cleat clamping element (42a).

15. The lawn mower cutting assembly (22) of claim 12, wherein: At least one of the lower anti-skid plate clamping element and the upper anti-skid plate clamping element (42a, 42b) defines an end member housing (55), and the lawn mower cutting assembly (22) also includes an end member cover (62) movable between a closed position and an open position, in which the end member cover covers the underside of the end member housing (55) and in which the end member cover exposes the end member (54; 154; 254) for access from below.

16. The lawn mower cutting assembly (22) of claim 15, wherein: The end piece cover (62) includes a bayonet joint (74) for connecting to a matching bayonet joint (66, 72) of the end piece housing (55), wherein a tangential wall (68) of the end piece housing (55) tangential to the cutting rotation axis (C) is provided with at least one anti-skid plate access opening (70), and the anti-skid plate (32) includes a central opening (64) provided with at least one supporting protrusion (66) extending radially inwardly and penetrating the anti-skid plate access opening (70), wherein the bayonet joint (74) of the end piece cover (62) is constructed to be axially supported by the supporting protrusion (66) when the end piece cover (62) is in a closed position.

17. The lawn mower cutting assembly (22) of claim 16, wherein: The upper cleat clamping element (42b) includes a cover protrusion (72) configured to abut and cover at least a portion of an upper surface of the support protrusion (66).

18. The lawn mower cutting assembly (22) of claim 15, wherein: The end piece cover (62) is connected to the cleat assembly (30) by a flexible strap (78) when in the open position.

19. A lawn mower cutting assembly (22) according to any one of claims 1 to 18, wherein: The axial position of the end member (54; 254) relative to the cutting drive shaft (34; 134; 234) can be reconfigured so that the end member (54; 254) can abut against the axial stop shoulder (60; 260) to clamp the anti-slip device (30) and the knife holder device (26; 126；226)。 20. The lawn mower cutting assembly (22) according to any one of claims 1 to 18, wherein: The end piece (54; 254) is threadably engaged with the cutting drive shaft (34; 234).

21. A lawn mower cutting assembly (22) according to any one of claims 1 to 18, wherein: The end piece (54) is configured to be axially retained to the cutting drive shaft (34) by a bolt (38) configured to engage an internal thread (49) of the cutting drive shaft (34).

22. The lawn mower cutting assembly (22) of claim 21, wherein: The tool holder device (26) has an internal thread (57), and the bolt (38) is constructed as a non-lost bolt (38), the non-lost bolt having: a bolt head (54); a threaded section (51) matching the internal thread (57) of the tool holder device (26); and a reduced width section (59) located between the bolt head (54) and the threaded section (51), the radial width of the reduced width section (59) being smaller than the radial width of the threaded section (51).

23. A lawn mower cutting assembly (22) according to any one of claims 1 to 18, in, The cleat assembly (30) and the blade holder assembly (26; 126; 226) are configured to be axially retained to the cutting drive shaft (34; 134; 234) by a single fastener (38; 154; 254).

24. A lawn mower cutting assembly (22) according to any one of claims 1 to 18, in, The anti-skid plate device (30) and the tool holder device (26) are axially held together by a non-lost bolt (38).

25. A lawn mower cutting assembly (22) according to any one of claims 1 to 18, in, The anti-skid plate device (30) can rotate relative to the tool holder device (26; 126; 226) via bearings (46a, 46b), and the bearings (46a, 46b) are arranged in a bearing housing (52), and Wherein, the lawn mower cutting assembly (22) further comprises: a bearing housing cover (62) movable between a closed position in which the bearing housing cover covers the underside of the bearing housing (52) and an open position in which the bearing housing cover exposes the bearing housing (52) for access from below, The bearing housing cover (62) is configured to be axially supported by an edge (66) of the anti-skid plate (32) when in the closed position.

26. A lawn mower cutting assembly (22) according to any one of claims 12 to 18, in, The anti-skid plate device (30) can rotate relative to the tool holder device (26; 126; 226) via bearings (46a, 46b), and the bearings (46a, 46b) are arranged in a bearing housing (52). Wherein, the lawn mower cutting assembly (22) further comprises: a bearing housing cover (62) movable between a closed position in which the bearing housing cover covers the underside of the bearing housing (52) and an open position in which the bearing housing cover exposes the bearing housing (52) for access from below, The anti-skid plate clamping elements (42a, 42b) are configured to clamp the anti-skid plate (32) between the anti-skid plate clamping elements when the bearing housing cover (62) is in the open position.

27. A robotic lawn mower comprising a lawn mower cutting assembly (22) according to any one of claims 1 to 26.

28. A method of attaching a lawn mower cutting assembly (22) according to any one of claims 1 to 26 to a lawn mower (14), the method comprising: Positioning the blade holder assembly (26; 126; 226) and the anti-skid plate assembly (30) on the cutting drive shaft (34; 134; 234) above; as well as Subsequently, the axial positions of the blade holder device (26; 126; 226) and the anti-skid plate device (30) relative to the cutting drive shaft (34; 134; 234) are axially locked.

Images