CN220886727U

CN220886727U - Grab bucket assembly and grab bucket of wood grabbing machine

Info

Publication number: CN220886727U
Application number: CN202322663346.7U
Authority: CN
Inventors: 王皓; 虞红海; 栾军林; 顾燚; 陈天亮; 崇庆国; 程昌福; 林家宇; 柯文彬
Original assignee: Taicang Wanfang International Port Co ltd
Current assignee: Taicang Wanfang International Port Co ltd
Priority date: 2023-09-30
Filing date: 2023-09-30
Publication date: 2024-05-03
Anticipated expiration: 2033-09-30

Abstract

The utility model discloses a grab bucket assembly and a grab bucket of a wood grabbing machine, which are characterized in that: the novel multifunctional scraper comprises a scraper body, wherein the bottom of the scraper body is provided with a tooth tip, the bottom of the tooth tip is provided with a notch, two ends of the notch are respectively close to the front end face and the rear end face of the tooth tip, and a guide protection mechanism is arranged in the notch; the guide protection mechanism comprises a roller shaft and a plurality of rollers rotatably arranged on the outer surface of the roller shaft, the roller shaft is arranged in the notch through a connecting component, one end of the connecting component is connected with the roller shaft, the other end of the connecting component is arranged on the tooth point, and the rollers are arranged on the outer surface of the roller shaft at intervals from front to back; the bottom surface of gyro wheel set up in the bottom surface below of breach, the left side surface and the right side surface of gyro wheel set up respectively in the left side outside and the right side outside of breach. The utility model reduces the breakage rate of log and is convenient for the maintenance and replacement of the roller.

Description

Grab bucket assembly and grab bucket of wood grabbing machine

Technical Field

The utility model relates to a grab bucket, in particular to a grab bucket assembly and a grab bucket of a wood grabbing machine.

Background

When the log is grabbed and loaded and unloaded at a wharf or the like, the log is required to be loaded and unloaded by utilizing the grab bucket of the log grabbing machine. When the grab bucket is opened and closed, the hydraulic cylinder pushes the grab bucket to open and close.

In the prior art, referring to fig. 1, the grab bucket of the wood grabbing machine comprises a spandrel girder 101, two hydraulic cylinders 102 and two bucket bodies 103, wherein the tops of the two bucket bodies are respectively and rotatably connected with two sides of the bottom of the spandrel girder, the bottoms of the bucket bodies are tooth tips, the bottoms of the bucket bodies are sharp, the tops of the two hydraulic cylinders are respectively and rotatably connected with two sides of the top of the spandrel girder, the bottoms of the two bucket bodies are respectively and rotatably connected with the upper parts of the two bucket bodies, and when an output shaft of the hydraulic cylinder stretches out, the bottoms of the two bucket bodies are pushed to be close to realize closure. When the output shaft of the hydraulic cylinder is retracted, the bottoms of the two bucket bodies are driven to be far away, so that the opening is realized, and when the bucket bodies are opened, the log is released.

However, the above structure has the following disadvantages:

1. In order to facilitate the insertion of the tooth tips of the bucket bodies between adjacent logs, thereby realizing the grabbing of the logs, the bottom of the tooth tips is more pointed, so that the tooth tips cannot be opposite to the adjacent logs each time when the bucket bodies are closed to grab the logs, and the tooth tips are easy to cut the logs (the tooth tips are more like a knife and are easy to damage the logs), thereby leading to higher breakage rate of the logs;

2. When the bucket body grabs the log, the tooth point can be inserted on the log, so that the bucket body can be subjected to the resistance of the log when being closed, the required thrust of the hydraulic cylinder is larger, the hydraulic cylinder is easy to damage, and the maintenance rate is high.

Therefore, how to solve the above technical problems is a direction that a person skilled in the art needs to make efforts.

Disclosure of Invention

The utility model aims to provide a grab bucket assembly and a grab bucket of a log grabbing machine, which can ensure grabbing convenience in a log grabbing process, reduce damage to logs, reduce maintenance rate and reduce maintenance cost.

In order to achieve the above purpose, the utility model adopts the following technical scheme: the grab bucket assembly comprises a bucket body, wherein the bottom of the bucket body is provided with a tooth tip, the bottom of the tooth tip is provided with a notch, two ends of the notch are respectively close to the front end face and the rear end face of the tooth tip, and a guide protection mechanism is arranged in the notch;

The guide protection mechanism comprises a roller shaft and a plurality of rollers rotatably arranged on the outer surface of the roller shaft, the roller shaft is arranged in the notch through a connecting component, one end of the connecting component is connected with the roller shaft, the other end of the connecting component is arranged on the tooth point, and the rollers are arranged on the outer surface of the roller shaft at intervals from front to back;

The bottom surface of gyro wheel set up in the bottom surface below of breach, the left side surface and the right side surface of gyro wheel set up respectively in the left side outside and the right side outside of breach.

In the technical scheme, a plurality of mounting holes are formed in the outer surface of the top of the roller shaft at intervals, the plurality of mounting holes are formed in the front-to-back mode at intervals, and the mounting holes are perpendicular to the axis of the roller shaft;

a plurality of cavities are arranged on the tooth tips above the gaps, two ends of each cavity are respectively communicated with the left side face and the right side face of the tooth tip, at least one through hole is arranged at the bottom of each cavity and communicated with the gaps, and each through hole is opposite to one mounting hole;

The connecting components are multiple groups, the middle part of each group of connecting component is inserted in one through hole, the bottom of each connecting component is connected with one mounting hole, the top of each connecting component is inserted in the corresponding cavity, and the connecting components are used for connecting the roller shafts with the tooth tips.

In the above technical scheme, the mounting hole is a stepped hole and comprises an upper hole and a lower hole which are coaxially arranged, the top of the upper hole is communicated with the top outer surface of the roller shaft, the top of the lower hole is communicated with the bottom of the upper hole, the bottom of the lower hole is communicated with the bottom outer surface of the roller shaft, and the diameter of the lower hole is larger than that of the upper hole;

The connecting component comprises a screw rod and a nut, a screw head is arranged at the bottom of the screw rod, the screw head is arranged in the lower hole, and the outer edge of the top surface of the screw head is propped against the top surface of the lower hole;

The top of the screw rod sequentially penetrates through the upper hole and the through hole to be inserted into the cavity, the nut is in threaded connection with the top of the screw rod, and the bottom surface of the nut abuts against the bottom surface of the cavity.

In the technical scheme, the outer diameter of the screw head is larger than the diameter of the upper hole, the shape of the lower hole is matched with the shape of the screw head, and the diameter of the nut is larger than the diameter of the through hole.

In the above technical scheme, the bottom surface of the screw head is arranged in the lower hole.

In the above technical scheme, the top surface of breach is equipped with a plurality of grooves of stepping down from front to back, every the top of gyro wheel set up in one the groove of stepping down.

In the above technical scheme, the top surface of breach is the arcwall face, the arcwall face with the surface phase-match of roller shaft, the top surface of roller shaft support in on the arcwall face.

In the above technical scheme, the bottom outer surface of the roller shaft is arranged in the notch.

The utility model also provides a grab bucket of the wood grabbing machine, which comprises a spandrel girder and a driving mechanism, and further comprises two groups of grab bucket components, wherein the tops of the two grab bucket components are respectively and rotatably connected with two sides of the bottom of the spandrel girder, the driving mechanism is arranged on the spandrel girder, and the driving mechanism drives the bottoms of the two grab bucket components to open or close and enables the bottoms of tooth tips on the two grab bucket components to be far away from or close to each other.

In the above technical scheme, the driving mechanism comprises two hydraulic cylinders, each hydraulic cylinder is respectively arranged at two sides of the bolster, the top of each hydraulic cylinder is rotationally connected with the side wall above the bolster, and the output shaft at the bottom of each hydraulic cylinder is rotationally connected with the upper part of a corresponding bucket body;

And/or, when the output shafts of the hydraulic cylinders retract, the bottoms of the two bucket bodies are driven to open; when the output shafts of the hydraulic cylinders extend out, the bottoms of the two bucket bodies are driven to be closed.

Due to the application of the technical scheme, compared with the prior art, the utility model has the following advantages:

1. According to the utility model, the notch is arranged at the bottom of the tooth tip, the plurality of rollers are arranged in the notch, the rollers are rotatably arranged on the roller shafts, and the outer diameter of each roller is larger than the thickness of the tooth tip, so that the rollers are in rolling contact with the raw wood when the grab bucket grabs the raw wood, the tooth tip can be prevented from grabbing the raw wood, and the breakage rate of the raw wood can be effectively reduced;

2. In the utility model, the mounting hole is directly arranged on the roller shaft, and the roller shaft is fixed on the tooth tip through the connecting component passing through the mounting hole, so that the roller is convenient to maintain and disassemble;

3. According to the utility model, the mounting hole adopts the stepped hole, the connecting component adopts the screw, the screw head at the bottom of the screw is directly inserted into the lower hole at the bottom of the mounting hole, and the top of the screw is limited by the nut, so that the strength of the roller shaft after being mounted is better, the roller shaft can be prevented from loosening during use, the assembly process of the roller shaft is simplified, the assembly time of the roller shaft is shortened, and the maintenance convenience is improved.

Drawings

FIG. 1 is a schematic diagram of a structure in the background art;

FIG. 2 is a schematic view of a grapple assembly according to a first embodiment of the present utility model;

FIG. 3 is a schematic view showing an end face structure at the bottom of a tooth tip in accordance with the first embodiment of the present utility model;

FIG. 4 is a schematic cross-sectional view of the bottom of the tooth tip in accordance with one embodiment of the present utility model;

FIG. 5 is a schematic cross-sectional view of the junction of a roller shaft and a tooth tip in accordance with one embodiment of the present utility model;

fig. 6 is a schematic structural view of a grapple of the wood grab according to the first embodiment of the present utility model;

FIG. 7 is a schematic cross-sectional view of the junction of the roller shaft and the tooth tip in comparative example one;

Fig. 8 is a schematic cross-sectional view of the junction of the roller shaft and the tooth tip in comparative example two.

Wherein: 1. a bucket body; 2. tooth tips; 3. a notch; 4. a roller shaft; 5. a roller; 6. a connection assembly; 7. a bolster; 8. a hydraulic cylinder; 9. a mounting hole; 10. a cavity; 11. a through hole; 12. an upper hole; 13. a lower hole; 14. a screw; 15. a nut; 16. a screw head; 17. an arc surface; 18. a relief groove;

101. a bolster; 102. a hydraulic cylinder; 103. a bucket body.

Detailed Description

The utility model is further described below with reference to the accompanying drawings and examples:

Embodiment one: referring to fig. 2-6, a grab bucket assembly comprises a bucket body 1, wherein the bottom of the bucket body 1 is provided with a tooth tip 2, the bottom of the tooth tip 2 is provided with a notch 3, two ends of the notch 3 are respectively close to the front end face and the rear end face of the tooth tip 2, and a guide protection mechanism is arranged in the notch 3;

The guide protection mechanism comprises a roller shaft 4 and a plurality of rollers 5 rotatably arranged on the outer surface of the roller shaft 4, the roller shaft 4 is arranged in the notch 3 through a connecting component 6, one end of the connecting component 6 is connected with the roller shaft 4, the other end of the connecting component is arranged on the tooth point 2, and the plurality of rollers 5 are arranged on the outer surface of the roller shaft 4 at intervals from front to back;

Referring to fig. 6, the utility model further provides a grab bucket of the wood grabbing machine, which comprises a spandrel girder 7 and a driving mechanism, and further comprises the grab bucket assembly, wherein the two grab bucket assemblies are arranged in two groups, the tops of the two grab bucket bodies 1 are respectively and rotatably connected with two sides of the bottom of the spandrel girder 7, the driving mechanism is arranged on the spandrel girder 7, and drives the bottoms of the two grab bucket bodies 1 to open or close, and the bottoms of the tooth tips 2 on the two grab bucket bodies 1 are far away from each other or are close to each other.

The driving mechanism comprises two hydraulic cylinders 8, each hydraulic cylinder 8 is respectively arranged at two sides of the spandrel girder 7, the top of each hydraulic cylinder 8 is rotationally connected with the side wall above the spandrel girder 7, and an output shaft at the bottom of each hydraulic cylinder 8 is rotationally connected with the upper part of a corresponding bucket body 1;

when the output shafts of the hydraulic cylinders retract, the bottoms of the two bucket bodies are driven to open; when the output shafts of the hydraulic cylinders extend out, the bottoms of the two bucket bodies are driven to be closed.

In this embodiment, the top and the equipment of spandrel girder are connected, when needs snatch the log, under initial condition, the output shaft of two pneumatic cylinders is retracted, make the top of bucket body rotate around the spandrel girder, the bottom of bucket body outwards upper side rotates, the tooth point of two bucket bodies is kept away from each other like this, realize opening of grab bucket, wherein, the bucket body is the arc structure, the arc opening of two bucket bodies sets up inwards, its arc convex part outwards sets up, when snatching the log, the output shaft of two pneumatic cylinders stretches out, promote the bucket body rotation, make the bottom of two bucket bodies be close to each other, when being close to each other, the tooth point then can be in contact with the log in advance, because the bottom of tooth point has a plurality of gyro wheels, the surface contact with the log like this, can not harm the log, when being close to each other like this two bucket body bottoms can extrude, make tooth point and gyro wheel can promote log up or down to remove, make gear and tooth point can insert between adjacent log, until the tooth point of two bucket body bottoms is close to each other, thereby snatch many log. Therefore, when the log is grabbed, the tooth tips cannot be directly inserted into the log to damage the log, or the damage is small, so that the breakage rate of the log during grabbing can be effectively reduced. When the log is required to be released, the output shaft of the hydraulic cylinder retracts to drive the bucket body to rotate, so that the bottom of the tooth tip rotates outwards and upwards, and the log can be released.

Referring to fig. 3 to 5, a plurality of mounting holes 9 are formed in the top outer surface of the roller shaft 4 at intervals, the plurality of mounting holes 9 are formed in the front-back direction at intervals, and the mounting holes 9 are perpendicular to the axis of the roller shaft 4;

A plurality of cavities 10 are arranged on the tooth tip above the notch 3, two ends of each cavity 10 are respectively communicated with the left side face and the right side face of the tooth tip, at least one through hole 11 is arranged at the bottom of each cavity and is communicated with the notch 3, and each through hole 11 is opposite to one mounting hole 9;

The roller is rotatably arranged on the roller shaft, and when the grab bucket is used, the roller and the roller shaft need to bear large force, and the force born by the roller shaft can be transmitted to the tooth point through the connecting component. When the roller is used, the roller shaft and the connecting assembly can bear larger force, so that the roller, the roller shaft and the connecting assembly can be damaged, and the roller shaft are required to be of detachable structures so as to be convenient to maintain and replace. Therefore, the installation hole is formed in the roller shaft, the cavity is formed in the tooth tip, the through hole is formed in the tooth tip to connect the cavity with the notch, and the connecting assembly can be inserted into the through hole, the cavity and the installation hole to connect the roller shaft with the tooth tip so as to facilitate subsequent disassembly. Meanwhile, mounting holes, namely connecting components, are formed between adjacent rollers, and mounting holes are formed in the two ends of the roller shafts, so that the roller shafts and the tooth tips are connected through a plurality of connecting components, the connecting components are arranged on the two sides of each roller, the two sides of each roller are reinforced through the connecting components and the tooth tips, the strength of the rollers and the roller shafts can be improved, and the roller shafts are prevented from being deformed and damaged.

Further, referring to fig. 4 and 5, the mounting hole 9 is a stepped hole, and includes an upper hole 12 and a lower hole 13 coaxially disposed, wherein the top of the upper hole 12 is communicated with the top outer surface of the roller shaft 4, the top of the lower hole 13 is communicated with the bottom of the upper hole 12, the bottom of the lower hole 13 is communicated with the bottom outer surface of the roller shaft 4, and the diameter of the lower hole 13 is larger than the diameter of the upper hole 12;

The connecting assembly 6 comprises a screw 14 and a nut 15, a screw head 16 is arranged at the bottom of the screw 14, the screw head 16 is arranged in the lower hole 13, and the outer edge of the top surface of the screw head 16 is propped against the top surface of the lower hole 13;

The outer diameter of the screw head is larger than the diameter of the upper hole, the shape of the lower hole is matched with the shape of the screw head, and the diameter of the nut is larger than the diameter of the through hole.

The bottom surface of the screw head is arranged in the lower hole.

In this embodiment, the screw head and the screw rod are of an integral structure, so when the roller shaft is installed, the bucket body is directly lifted, then the roller shaft with the rollers is placed into the notch, each installation hole is opposite to one through hole, then the top of the screw rod is penetrated upwards from the lower hole and then inserted into the cavity after passing through the upper hole and the through hole, wherein the screw head is inserted into the lower hole, the shape of the lower hole is matched with the shape of the screw head, the section of the screw head is of a hexagonal structure, the section of the lower hole is of a hexagonal structure, of course, the section of the lower hole can also be of a quadrangular structure, in this embodiment, the lower hole and the screw head are of polygonal structures, at least three sides can also be of an ellipse, after the lower hole cannot be of a circle shape, the screw rod is installed, the nut is placed into the cavity, and the top of the screw rod is screwed, so that the installation of the screw rod can be completed, the roller shaft can be locked in the notch by the nut, the limit of the roller shaft and the tooth shaft can be connected, and the roller shaft can also be prevented from rotating. Meanwhile, in the embodiment, the adjacent cavities can have height difference, so that the cavities are not all arranged on the same plane, the strength of the tooth tip is ensured as much as possible, and the damage of the tooth tip is prevented. Therefore, if the cavities are not all on the same plane, the length of the screw rod can be selected according to the position of the cavities, the lengths of the screw rods in the plurality of connecting assemblies are not all the same, and the length of the screw rods can be selected according to the distance between the cavities and the roller shafts.

In this embodiment, the stepped hole is directly formed on the roller shaft, and the screw head with an integral structure is arranged at the bottom of the bolt, so that the roller shaft and the tooth tip are convenient to mount and dismount.

As a comparative example, there are two ways in designing the roller shaft and the connection assembly, in which, as shown in fig. 7, comparative example one: the surface of the roller shaft is provided with a mounting hole 9 which is a blind hole, the mounting hole adopts a screw hole, the top and the bottom of the screw rod 14 are respectively provided with external threads, the bottom of the screw rod is in threaded connection with the mounting hole in advance, the top of the screw rod penetrates through the through hole to be inserted into the cavity, and then the locking and the fixing of the roller shaft and the tooth tip are realized by utilizing the external threads of the nut 15 and the top of the screw rod.

However, in this way, the rollers are damaged due to frequent friction with the log during use, and therefore, the rollers need to be replaced. However, when the roller is replaced, the screw and the mounting hole are required to be detached, so that the roller can be detached from the roller shaft. However, after the subsequent reinstallation, the roller shaft is loosened, namely, the connection part of the roller shaft and the screw rod is loosened, and in order to prevent the looseness, the connection part of the screw rod and the mounting hole is coated with the thread compound, because the thread compound becomes firm thermosetting plastic after being formed, the thread compound can thoroughly fill the thread gap, the matched threads can be integrated, the friction force between the threads is maximum, and the roller shaft can be prevented from loosening during operation. However, the thread compound is cured from a liquid state to a solid thermosetting plastic, an oxygen-deficient sealing environment needs to be created for the thread compound, and the thread compound is kept in a static state for at least 24 hours, otherwise, the effect of complete curing cannot be achieved. The wood grabbing machine belongs to large-scale key equipment with higher utilization rate like the portal crane, and the loading and unloading capacity of the large-scale key equipment can be seriously influenced if the large-scale key equipment is stopped. The rollers are replaced on average about 2 months, approximately 6 times a year. If the machine is stopped for 24 hours each time the rollers are replaced, the machine can be stopped for 144 hours only by replacing the rollers in one year, and the capacity of the machine is seriously affected, so that the method is unsuitable.

Referring to fig. 8, in the second comparative example, the mounting hole 9 is formed on the surface of the roller shaft, which is a stepped through hole, the top and bottom of the screw 14 are provided with external threads, the bottom of the screw is inserted into the stepped through hole, a nut 15 is screwed to the bottom of the stepped through hole, the bottom of the screw is screwed, the top of the screw is inserted into the cavity through the through hole, and then the roller shaft and the tooth tip are locked and fixed by using the two nuts and the screw by using the external threads of the top of the nut and the screw.

In this kind of structure, solved the time consuming problem in comparative example 1, the problem of becoming flexible also can be solved, but both ends need to adopt the nut to carry out the spiro union with the screw rod, the process is more, maintenance change time is longer, and in the utility model, can set up 6 gyro wheels, set up 6 screw rods, namely need 12 nuts, the dismouting of 12 nuts on a bucket body just needs to take approximately 2 hours, and efficiency is lower, and operating personnel intensity of labour is also higher.

Therefore, in this embodiment, the screw head of an integral structure is directly disposed at the bottom of the screw, so that only 6 nuts need to be mounted on each bucket body (only one nut needs to be mounted on each screw, if the number of rollers is more, the number of connecting assemblies is also more, that is, the number of screws is also more, in this embodiment, the number of screws is more than the number of rollers by one), the dismounting efficiency is high, and the labor intensity of operators is also lower.

Referring to fig. 4 and 5, the top surface of the notch is provided with a plurality of relief grooves 18 from front to back, and the upper part of each roller 5 is disposed in one relief groove 18.

The top surface of breach is arcwall face 17, arcwall face with the surface phase-match of roller shaft, the top surface of roller shaft supports on the arcwall face.

The bottom outer surface of the roller shaft is arranged in the notch.

In this embodiment, the top surface of roller shaft supports on the arcwall face at breach top, and the area of contact of roller shaft and tooth point is bigger like this, and its unsettled mounting means, after the gyro wheel atress, the roller shaft can support through the arcwall face to increase the intensity of roller shaft, increase of service life prevents the roller shaft deformation. The setting of breach gives the gyro wheel and gives the position, and the gyro wheel axle is in the breach moreover, does not expose, when snatching the log like this, the gyro wheel axle can not contact with the log, only gyro wheel and log contact, can only have the gyro wheel like this can be impaired, the gyro wheel axle can not be impaired, in the time of follow-up maintenance change, only need change the gyro wheel can.

In the description of the present utility model, it should be understood that the directions or positional relationships indicated by the terms "upper", "lower", "top", "bottom", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present utility model. In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; the two components can be directly connected or indirectly connected through an intermediate medium, for example, the two components can form a mechanical abutting or abutting connection mode through abutting, contact and the like, the two components can be directly connected or hung through the intermediate medium, and the two components can be communicated inside the two components or the interaction relationship of the two components. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

Claims

1. A grab bucket assembly, characterized in that: the novel multifunctional scraper comprises a scraper body, wherein the bottom of the scraper body is provided with a tooth tip, the bottom of the tooth tip is provided with a notch, two ends of the notch are respectively close to the front end face and the rear end face of the tooth tip, and a guide protection mechanism is arranged in the notch;

2. The grapple assembly of claim 1, wherein: a plurality of mounting holes are formed in the outer surface of the top of the roller shaft at intervals, the mounting holes are formed in the front-back intervals, and the mounting holes are perpendicular to the axis of the roller shaft;

3. The grapple assembly of claim 2, wherein: the mounting hole is a stepped hole and comprises an upper hole and a lower hole which are coaxially arranged, the top of the upper hole is communicated with the outer surface of the top of the roller shaft, the top of the lower hole is communicated with the bottom of the upper hole, the bottom of the lower hole is communicated with the outer surface of the bottom of the roller shaft, and the diameter of the lower hole is larger than that of the upper hole;

4. A grapple assembly according to claim 3, characterized in that: the outer diameter of the screw head is larger than the diameter of the upper hole, the shape of the lower hole is matched with the shape of the screw head, and the diameter of the nut is larger than the diameter of the through hole.

5. A grapple assembly according to claim 3, characterized in that: the bottom surface of the screw head is arranged in the lower hole.

6. The grapple assembly of claim 1, wherein: the top surface of breach is equipped with a plurality of grooves of stepping down from front to back, every the top of gyro wheel set up in one the groove of stepping down.

7. The grapple assembly of claim 6, wherein: the top surface of breach is the arcwall face, the arcwall face with the surface phase-match of roller shaft, the top surface of roller shaft supports in the arcwall face is last.

8. The grapple assembly of claim 1, wherein: the bottom outer surface of the roller shaft is arranged in the notch.

9. Grab bucket of grab wood machine, its characterized in that: the grab bucket comprises a spandrel girder and a driving mechanism, and further comprises two grab bucket assemblies according to any one of claims 1-8, wherein the two grab bucket assemblies are arranged in two groups, the tops of the two grab bucket assemblies are respectively connected with two sides of the bottom of the spandrel girder in a rotating mode, the driving mechanism is arranged on the spandrel girder and drives the bottoms of the two grab bucket assemblies to open or close, and the bottoms of tooth tips on the two grab bucket assemblies are far away from each other or are close to each other.

10. The grapple of claim 9 wherein: the driving mechanism comprises two hydraulic cylinders, each hydraulic cylinder is respectively arranged at two sides of the bolster, the top of each hydraulic cylinder is rotationally connected with the side wall above the bolster, and an output shaft at the bottom of each hydraulic cylinder is rotationally connected with the upper part of a corresponding bucket body;