CN117207229A - Flower-shaped mechanical arm tail end quick-dismantling mechanism - Google Patents

Abstract

The invention discloses a flower-shaped mechanical arm end quick-release mechanism, which belongs to the field of medical equipment. It includes: a flower-shaped mandrel, which is provided with an arc channel for connecting the end effector; and a sleeve, which is provided with a flower-shaped channel. , used to accommodate the flower-shaped mandrel, which cannot rotate circumferentially when the flower-shaped mandrel is slidingly connected to the flower-shaped channel; the limiting pin is rotatably connected to the sleeve, and the limiting pin is provided with an arc pin, rotate the limit pin to insert the arc-shaped pin into the arc-shaped channel, so that the flower-shaped mandrel cannot be displaced in the axial direction; the end connection seat is used to connect the mechanical arm; the transfer connection seat is provided at the end connection seat and the sleeve, and is coaxially connected to the end connection seat. Through the above arrangement, the present invention can be connected between the robotic arm and the end connection device, and can assist the end effector and the robotic arm in completing assembly or disassembly with high precision and efficiency.

Description

A quick-release mechanism at the end of a flower-shaped robotic arm

Technical field

The invention belongs to the technical field of medical devices, and specifically relates to a quick-release mechanism at the end of a flower-shaped mechanical arm.

Background technique

With the development of science and technology, robots are increasingly used in medical surgeries. Medical robots assist manual operations, making operations more precise. Usually the robotic arm is connected to the end effector, and the end effector needs to be disassembled, disinfected and sterilized before and after surgery. During surgery, it is sometimes necessary to replace the end effector. This requires rapid installation and disassembly of the end effector, and ensuring the stability and installation accuracy of the end effector after installation. The existing robotic arm and the end effector are mainly connected by screws or large external thread rotation. Although these two connection methods are stable and firm, they have the problem of slow installation speed, which is not conducive to smooth and efficient surgery.

The screw connection solution requires additional tools, and the operation steps are many and the operation process is relatively complicated; the external large thread rotary connection solution requires a lot of rotations; the installation and disassembly of these two connection methods are complex and time-consuming, and directly affect surgical efficiency.

Therefore, it is necessary to design an instrument that can assist the end effector and the robotic arm to complete assembly or disassembly with high precision and efficiency, thereby solving the above technical problems. This instrument is specifically a flower-shaped robotic arm end quick-release mechanism.

Contents of the invention

In order to overcome the problems raised in the background technology, the present invention adopts the following technical solutions:

A flower-shaped mechanical arm end quick-release mechanism, including: a first connection structure, used to connect the end effector, including a sleeve and a flower-shaped mandrel with an arc channel, and a flower-shaped mandrel is provided on the sleeve. channel, the flower-shaped mandrel cannot rotate circumferentially when it is slidingly connected to the flower-shaped channel; the limiting pin is rotatably connected to the sleeve, and the limiting pin is provided with an arc-shaped pin. Rotating the limiting pin causes the The arc-shaped pin is inserted into the arc-shaped channel so that the flower-shaped mandrel cannot be displaced in the axial direction; the second connection structure is used to connect the mechanical arm, including a coaxially connected transfer connection seat and an end connection seat. The connecting seat is connected to the sleeve, and the end connecting seat is connected to the mechanical arm.

Further, the sleeve includes a top plate provided with uprights and a chassis provided with sockets. The limit pin is sleeve-connected to the uprights. The chassis is coaxial with the top plate, and the uprights are connected to the uprights. The socket is adapted so that the top plate and the bottom plate can form a sleeve and limit the axial displacement of the limit pin along the column.

Further, the flower-shaped channel includes a flower-shaped top groove that penetrates the top disk along the axial direction of the top disk and a flower-shaped bottom groove that penetrates the chassis along the axial direction of the chassis. The top disk is plugged into the chassis. When the flower-shaped top groove and the flower-shaped bottom groove are not aligned along the axial direction of the column, when the flower-shaped mandrel passes through the top plate, it needs to be rotated circumferentially to fit into the flower-shaped bottom groove; even if The arc pin breaks and the flower-shaped mandrel moves toward the top plate. The flower-shaped mandrel is also limited by the flower-shaped top groove on the top plate to prevent the end effector from slipping directly from the sleeve when the arc pin breaks. And affect the surgical process or even cause serious harm to patients or medical staff.

Further, the flower-shaped mandrel includes mandrel petals and a connecting shaft, the mandrel petals are integrally connected with the connecting shaft, the arc-shaped channel is threaded on the connecting shaft, and the mandrel petals are connected with the connecting shaft. Described flower-shaped channel adaptation.

Further, the outer contour of the section perpendicular to the axis direction of the connecting shaft on the mandrel petals is composed of at least three petal-shaped arcs, and the inner contours of the flower-shaped top groove and the flower-shaped bottom groove are both consistent with the described flower-shaped top groove. The outer contours of the mandrel petals are the same or similar, but the area of the inner contour of the flower-shaped top groove and the area of the inner contour of the flower-shaped bottom groove are both larger than the area of the outer contour of the mandrel petals.

Further, the number of the upright columns is no less than three, the number of the upright columns is the same as the number of the sockets, and the distribution positions of the upright columns on the top plate are the same as the distribution positions of the sockets on the chassis, So that the axes of the top plate and the chassis after they are connected coincide with each other.

Further, a limiting block is also provided on the limiting pin; the limiting block is arc-shaped, the arc-shaped pin is connected to the side of the limiting block close to the connecting shaft, and the limiting block is close to the connecting shaft. One side of the shaft can abut and fit against the outer wall of the connecting shaft.

Further, the limit pin is also provided with an upright sleeve, and a connecting rod is provided between the upright sleeve and the limit block; the upright sleeve is sleeved on the upright column, and along the axial direction of the upright column: the length of the upright sleeve is shorter than the upright column. The length of the vertical sleeve is not less than the thickness of the mandrel petals, so that the mandrel petals can rotate circumferentially after passing through the flower-shaped top groove and before entering the flower-shaped bottom groove.

Further, the connecting shaft has internal threads on the inside thereof, and the connecting shaft is connected to the end effector through the internal threads, and the internal threads coincide with the axis of the connecting shaft.

Further, the outer wall of the transfer connection seat is machined with a large round external thread, and the inside of the end connection seat is machined with a large round internal thread. The large round internal thread is adapted to the large round external thread, so that the transfer connection The base is detachably connected to the end connection base.

Further, the transfer connection base is provided with a flat bottom. When the transfer connection base is connected to the end connection base, any point on the transfer connection base is selected as a, and any point on the flat bottom is on the large circle. The distance between the external thread and a in the axial direction is equal to ensure that the large circular external thread is coaxial with the chassis when the adapter connection seat is in contact with the chassis.

Further, one end of the chassis and the end connecting seat connected to the mechanical arm is provided with a bolt hole. The bolt hole penetrates the end connecting seat along the axis direction of the large circular internal thread. The end connecting seat is connected to the mechanical arm bolt through the bolt hole. connect.

Beneficial effects of the present invention:

1. By arranging a flower-shaped mandrel and a sleeve that can be passed through by the flower-shaped mandrel, the flower-shaped mandrel can be quickly connected to the sleeve and after the connection, the flower-shaped mandrel cannot rotate around the axis of the connecting shaft. , and then through the insertion of the arc pin on the limit pin and the arc channel, the flower-shaped mandrel cannot move along the axis direction of the connecting shaft, so that the end effector connected to the flower-shaped mandrel can be easily and quickly realized. Rapid limit assembly can greatly save time in the assembly and disassembly process while ensuring accuracy, so it has better practical effects.

2. By arranging a flower-shaped mandrel with a flower-shaped outline composed of multiple identical arcs, the assembled flower-shaped mandrel cannot rotate axially; the flower-shaped outline is smooth and has no edges, so the flower-shaped mandrel is repeatedly It not only has a high service life during disassembly and assembly, but also will not scratch medical staff.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of the front side of the present invention in the disassembled state;

Figure 2 is a schematic diagram of the overall structure of the rear side of the present invention when the disassembly is complete;

Figure 3 is a front view of the structure of the present invention in a disassembled state;

Figure 4 is a schematic diagram of the overall structure of the front and side of the present invention when the installation is completed;

Figure 5 is a structural front view of the present invention in a completed state;

Figure 6 is a left view of the structure of the present invention in a completed state;

Figure 7 is a schematic cross-sectional structural diagram of Figure 6;

Figure 8 is an exploded schematic diagram of the overall structure of the present invention;

Figure 9 is a schematic diagram of the overall structure of the flower-shaped mandrel, limit pin, and chassis after assembly;

Figure 10 is a front view of the structure after assembly of the flower-shaped mandrel, limit pin, and chassis;

Figure 11 is a schematic diagram of the overall structure when the arc pin is completely separated from the arc channel based on Figure 9;

Figure 12 is a front view of the structure when the arc-shaped pin is completely separated from the arc-shaped channel based on Figure 10;

Figure 13 is a structural front view of the flower-shaped mandrel;

Figure 14 is a schematic cross-sectional structural diagram of a flower-shaped mandrel;

Figure 15 is a schematic diagram of the overall structure of the flower-shaped mandrel;

Figure 16 is a schematic diagram of the overall structure of the limit pin;

Figure 17 is a schematic diagram of the assembly of the present invention and the end effector;

Figure 18 is a schematic diagram of the overall assembly of the present invention, the end effector and the robotic arm;

In the figure, A. Quick-release mechanism; 1. Flower-shaped mandrel; 1-1. Shaft internal thread; 1-2. Mandrel petals; 1-3. Connecting shaft; 1-4. Arc channel; 2. Top Disk; 2-1, flower-shaped top groove; 2-2, column; 3, limit pin; 3-1, limit block; 3-2, connecting rod; 3-3, vertical sleeve; 3-4, arc Shaped pin; 4. Chassis; 4-1, flower-shaped bottom groove; 4-2, jack; 5. transfer connection seat; 5-1, large round external thread; 5-2, flat bottom; 6. end connection seat; 6-1. Large circular internal thread; 6-2. Bolt hole; B. Robotic arm; C. End effector.

Detailed ways

The following is a clear and complete description of the technical solutions in the embodiments of the present invention through specific specific embodiments. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of the embodiments. Those skilled in the art can refer to this Other advantages and effects of the present invention can be easily understood from the content disclosed in the specification. The present invention can also be implemented or applied through other different specific implementations. In the case of no conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments of the present invention, those of ordinary skill in the art can All other embodiments obtained without creative efforts belong to the scope of protection of the present invention.

A quick-release mechanism A at the end of a flower-shaped robotic arm B, as shown in Figures 1 to 18. A quick-release mechanism A at the end of a flower-shaped robotic arm B, including: a first connection structure for connecting the end effector C, It includes a sleeve and a flower-shaped mandrel 1 provided with arc-shaped channels 1-4. The arc-shaped channels 1-4 are provided on the connecting shaft 1-3 of the flower-shaped mandrel 1, and the sleeve is provided with a flower-shaped channel. The flower-shaped mandrel 1 cannot rotate circumferentially when it is slidably connected to the flower-shaped channel; the limit pin 3 is connected to the sleeve in a rotational manner. The limit pin 3 is provided with arc pins 3-4. Rotate the limit pin 3 to make the arc The shaped pins 3-4 are inserted into the arc-shaped channels 1-4, so that the flower-shaped mandrel 1 cannot be displaced in the axial direction; the second connection structure is used to connect the robot arm B, including a coaxially connected transfer connection seat 5 connected to the end The base 6, the transfer connection base 5 is connected to the sleeve, and the end connection base 6 is connected to the mechanical arm B.

A more preferred embodiment is that, as shown in Figures 1 to 18, the sleeve includes a top plate 2 with a column 2-2 and a bottom plate 4 with a socket 4-2. Both the top plate 2 and the bottom plate 4 are circular. Disc-shaped structure, the axis of the column 2-2 is parallel to the axis of the top plate 2, the axis of the jack 4-2 is parallel to the axis of the chassis 4, the limit pin 3 is connected to the column 2-2, the chassis 4 is connected to the top The disk 2 is coaxial, and the column 2-2 is adapted to the socket 4-2, so that the top disk 2 and the bottom plate 4 can form a sleeve and limit the axial displacement of the limit pin 3 along the column 2-2. The vertical cross-sectional shapes of the upright 2-2 and the jack 4-2 along their respective axial directions are the same. These cross-sectional shapes can be circular or rectangular, but the cross-sectional area of the jack 4-2 is larger than that of the upright 2-2, so that Make sure that post 2-2 can be inserted into jack 4-2.

A more preferred embodiment is that, as shown in Figures 1 to 18, the flower-shaped channel includes a flower-shaped top groove 2-1 that penetrates the top plate 2 along the axial direction of the top plate 2 and a flower-shaped top groove 2-1 that penetrates along the axial direction of the chassis 4. When the top plate 2 and the bottom plate 4 are plugged into the flower-shaped bottom groove 4-1 on the chassis 4, the flower-shaped top groove 2-1 and the flower-shaped bottom groove 4-1 are not aligned along the axial direction of the column 2-2. After the flower-shaped mandrel 1 passes through the top plate 2, it needs to be rotated in a circumferential direction in order to be properly inserted into the flower-shaped bottom groove 4-1; even if the arc pin 3-4 breaks and the flower-shaped mandrel 1 faces the top plate 2 moves, the flower-shaped mandrel 1 will also be limited by the flower-shaped top groove 2-1 on the top plate 2 to prevent the end effector C from directly slipping out of the sleeve and affecting the surgical process when the arc pin 3-4 breaks. It can even cause serious harm to patients or medical staff. When the arc-shaped pins 3-4 break, the reason for the movement of the flower-shaped mandrel 1 is specifically: it is pulled by gravity from the surgical instruments or other objects connected to the end effector C and the end connecting device.

A more preferred embodiment is, as shown in Figures 1 to 18, the flower-shaped mandrel 1 includes mandrel petals 1-2 and a connecting shaft 1-3. The mandrel petals 1-2 and the connecting shaft 1-3 are integrally connected, and the arc The shaped channel 1-4 is passed through the connecting shaft 1-3, and the mandrel petals 1-2 are adapted to the flower-shaped channel. The plane of the arc axis of the arc channel 1-4 is parallel to the plane perpendicular to the central axis of the connecting shaft 1-3. The arc axis is specifically a section of arc, and this section of arc is connected to the column connected by the limit pin 3. Any point on the axis of 2-2 is the center of the circle, so that the limit pin 3 only needs to rotate to insert the arc pin 3-4 into the arc channel 1-4. The limit pin 3 is also provided with a limit block 3-1; the limit block 3-1 is arc-shaped, and the arc-shaped pin 3-4 is connected to the side of the limit block 3-1 close to the connecting shaft 1-3, and the limit block 3-1 is arc-shaped. The side of the position block 3-1 close to the connecting shaft 1-3 can contact and fit with the outer wall of the connecting shaft 1-3. This allows the limit block 3-1 to abut and fit with the outer wall of the connecting shaft 1-3. The advantage of the setting is that it can make the connection between the limit pin 3 and the flower-shaped mandrel 1 more tightly and form a tension-based connection relationship at the connection, which is not easily damaged by the vibration generated by the flower-shaped mandrel 1 , and the tightly fitting connection can effectively avoid stress accumulation caused by the interaction between structures and structural damage based on stress effects, thereby improving the connection stability and improving the service life of the flower-shaped mandrel 1 and the limit pin 3. .

A more preferred embodiment is that, as shown in Figures 1-18, the outer contour of the cross-section perpendicular to the axis direction of the connecting shaft 1-3 on the mandrel petals 1-2 is composed of at least three petal-shaped arcs, and the flower-shaped top The inner contours of the groove 2-1 and the flower-shaped bottom groove 4-1 are the same or similar to the outer contour of the mandrel petals 1-2. The inner contour dimensions of the flower-shaped top groove 2-1 and the flower-shaped bottom groove 4-1 are the same. , but the area of the inner contour of the flower-shaped top groove 2-1 and the area of the inner contour of the flower-shaped bottom groove 4-1 are both larger than the area of the outer contour of the mandrel petals 1-2. The gap size between the outer contour of the mandrel petals 1-2 and the flower-shaped top groove 2-1 is not greater than 0.5mm. More specifically, the gap size range between the outer contour of the mandrel petals 1-2 and the flower-shaped top groove 2-1 is 0.2mm-0.3mm, so that the flower-shaped mandrel 1 can be inserted into the flower-shaped top groove 2-1 and the flower-shaped bottom groove 4-1, and at the same time, the flower-shaped mandrel 1 will not be inserted into the flower-shaped bottom groove 4-1. Shake.

A more preferred embodiment is, as shown in Figures 1 to 18, the number of uprights 2-2 is no less than three, the number of uprights 2-2 is the same as the number of jacks 4-2, and the uprights 2-2 are on the top plate. The distribution positions on 2 are the same as the distribution positions of jacks 4-2 on chassis 4, so that the axes of top plate 2 and chassis 4 coincide with each other after they are plugged in. When assembly is required, first install the top plate 2 with the uprights 2-2 One side abuts one side of the chassis 4 to make the top disk 2 and the chassis 4 parallel, and then keeps the disc-shaped top disk 2 and the chassis 4 coaxial, and then starts to rotate one of the top disk 2 or the chassis 4 , until the column 2-2 is rotated to the position where the jack 4-2 is aligned and in this state the flower-shaped top groove 2-1 and the flower-shaped bottom groove 4-1 are not aligned along the axis of the top plate 2, and finally the column 2- 2 Insert into socket 4-2 to complete the blind assembly of the sleeve.

Another more preferred implementation method is to first determine all the connection methods of the top plate 2 and the chassis 4 when the upright column 2-2 and the jack 4-2 can be plugged in, and then select the top plate 2 after assembly from these ways. The part coaxial with the chassis 4 is used as a first-level screening plan, and then the parts that can ensure that the flower-shaped top groove 2-1 and the flower-shaped bottom groove 4-1 are not aligned along the axis of the top plate 2 are selected from the first-level screening plan. As a secondary screening scheme, the secondary screening scheme is an assembly scheme. Compared with the blind assembly implementation, this embodiment can effectively reduce the wear on the column 2-2 and the chassis 4, and the assembly efficiency is higher.

A more preferred embodiment is that, as shown in Figures 1 to 18, the limit pin 3 is also provided with a vertical sleeve 3-3, and a connecting rod 3-2 is provided between the vertical sleeve 3-3 and the limit block 3-1. ; The upright sleeve 3-3 is sleeved on the upright column 2-2, along the axial direction of the upright column 2-2: the length of the upright sleeve 3-3 is less than the length of the upright column 2-2, and the length of the upright sleeve 3-3 is not less than the mandrel petal 1 -2 thickness, so that the mandrel petals 1-2 can rotate circumferentially after passing through the flower-shaped top groove 2-1 and before entering the flower-shaped bottom groove 4-1. The upright sleeve 3-3 is cylindrical as a whole, and a gap of 0.1mm-0.2mm is maintained between the inner wall of the upright sleeve 3-3 and the outer wall of the upright column 2-2, so that the upright sleeve 3-3 can wrap around the upright column 2-2 Under the premise of smooth rotation, the arc pin 3-4 on the limit block 3-1 can also be accurately inserted into the arc channel 1-4.

A more preferred embodiment is that, as shown in Figures 1 to 18, the connecting shaft 1-3 has an internal shaft thread 1-1, and the connecting shaft 1-3 is connected to the end effector C through the internal thread 1-1. The internal thread 1-1 of the shaft coincides with the axis of the connecting shaft 1-3. The outer wall of the transfer connection seat 5 has a large round external thread 5-1, and the internal part of the end connection seat 6 has a large round internal thread 6-1. The large round internal thread 6-1 is adapted to the large round external thread 5-1, so that the rotation The connection base 5 and the end connection base 6 are detachably connected.

A more preferred embodiment is that, as shown in Figures 1 to 18, the transfer connection base 5 is provided with a flat bottom 5-2. When the transfer connection base 5 is connected to the end connection base 6, any position on the transfer connection base 5 can be Select a point as a, and any point on the flat bottom 5-2 is equidistant from a in the axial direction of the large circular external thread 5-1, so that when the adapter connection seat 5 contacts the chassis 4, it can ensure that the large circular external thread 5-1 is in contact with a. The chassis 4 is coaxial. At the same time, this setting can also effectively ensure the coaxiality of the end effector C and the robotic arm B.

A more preferred embodiment is that, as shown in Figures 1 to 18, one end of the chassis 4 and the end connecting seat 6 connected to the mechanical arm B is provided with a bolt hole 6-2, and the bolt hole 6-2 is along the large circular internal thread 6-1. The axis direction passes through the end connection seat 6, and the end connection seat 6 is bolted to the mechanical arm B through the bolt holes 6-2.

Claims (10)

1. The utility model provides a flower-shaped arm terminal quick detach mechanism which characterized in that includes:

the flower-shaped mandrel is provided with an arc-shaped channel in a penetrating way and is used for being connected with the tail end executing device;

the sleeve is provided with a flower-shaped channel and is used for accommodating a flower-shaped mandrel, and the flower-shaped mandrel cannot circumferentially rotate when being connected to the flower-shaped channel in a sliding manner;

the limiting pin is rotationally connected with the sleeve, an arc-shaped pin is arranged on the limiting pin, and the arc-shaped pin is inserted into the arc-shaped channel by rotating the limiting pin, so that the flower-shaped mandrel cannot axially displace;

the tail end connecting seat is used for connecting the mechanical arm;

the adapter is arranged between the tail end connecting seat and the sleeve and is coaxially connected with the tail end connecting seat.

2. The quick release mechanism for a flower-shaped mechanical arm according to claim 1, wherein the sleeve comprises a top plate provided with a column and a bottom plate provided with a jack, the limiting pin is connected with the column in a sleeved mode, the bottom plate is coaxial with the top plate, and the column is matched with the jack, so that the top plate and the bottom plate can form the sleeve and limit the displacement of the limiting pin along the axial direction of the column.

3. The quick release mechanism for a tail end of a flower-shaped mechanical arm according to claim 2, wherein the flower-shaped channel comprises a flower-shaped top groove penetrating through the top disc and a flower-shaped bottom groove penetrating through the bottom disc, the flower-shaped top groove and the flower-shaped bottom groove are not aligned along the axial direction of the upright post when the top disc is inserted into the bottom disc, and the flower-shaped mandrel needs to be rotated circumferentially after penetrating through the top disc to be matched with the flower-shaped bottom groove.

4. A flower-shaped mechanical arm end quick release mechanism according to claim 3, wherein the flower-shaped mandrel comprises mandrel petals and a connecting shaft, the mandrel petals are integrally connected with the connecting shaft, the arc-shaped channel is arranged on the connecting shaft in a penetrating manner, and the mandrel petals are matched with the flower-shaped channel.

5. The quick release mechanism for the tail end of a flower-shaped mechanical arm according to claim 4, wherein the limiting pin is further provided with a limiting block; the limiting block is arc-shaped, the arc-shaped pin is connected to one side, close to the connecting shaft, of the limiting block, and one side, close to the connecting shaft, of the limiting block can be abutted to and attached to the outer wall of the connecting shaft.

6. The quick release mechanism for the tail end of the flower-shaped mechanical arm according to claim 5, wherein the limiting pin is further provided with a vertical sleeve, and a connecting rod is arranged between the vertical sleeve and the limiting block; the vertical sleeve is sleeved on the vertical column, and the vertical sleeve is axially connected with the vertical column along the vertical column: the length of the vertical sleeve is smaller than that of the upright post, and the length of the vertical sleeve is not smaller than the thickness of the mandrel petals, so that the mandrel petals can circumferentially rotate after penetrating through the flower-shaped top groove and before entering the flower-shaped bottom groove.

7. The quick release mechanism for a flower-shaped arm according to claim 4, wherein the connecting shaft is internally threaded, the connecting shaft is connected to the end effector by the internal shaft thread, and the internal shaft thread coincides with the axis of the connecting shaft.

8. The quick release mechanism of a flower-shaped arm according to claim 7, wherein the outer wall of the adaptor is provided with a round external thread, the inner part of the adaptor is provided with a round internal thread, and the round internal thread is adapted to the round external thread, so that the adaptor is detachably connected to the adaptor.

9. The quick release mechanism for a flower-shaped mechanical arm according to claim 8, wherein a flat bottom is provided on the adapter, and when the adapter is connected with the end connector, a point a is optionally selected on the adapter, and the distance between any point on the flat bottom and a in the axial direction of the large circular external thread is equal, so that the adapter and the chassis can ensure that the large circular external thread and the chassis are coaxial when the adapter is abutted.

10. The quick release mechanism for a flower-shaped mechanical arm according to claim 9, wherein the chassis and one end of the end connecting seat connected with the mechanical arm are provided with bolt holes, the bolt holes penetrate through the end connecting seat along the axial direction of the large round internal threads, and the end connecting seat is connected with the mechanical arm through the bolt holes.