A mandibular combination adjustment mechanism and a bionic robot

Abstract

This application provides a mandibular assembly adjustment mechanism and a bionic robot, including a chin skeleton; two sets of ball bearing adjustment mechanisms, respectively connected to both ends of the chin skeleton; each ball bearing adjustment mechanism includes a mounting plate and elastic balls, one end of the mounting plate has multiple recessed holes distributed in a ring, and the elastic balls are elastically connected to the corresponding end sidewall of the chin skeleton; the end of the chin skeleton is hinged to one end of the mounting plate, so that when the chin skeleton rotates around the hinge point, the elastic balls can be embedded in the corresponding recessed holes; two movable swing arms are respectively connected to the ends of the two mounting plates away from the chin skeleton; one movable swing arm is connected to the robot head via a drive assembly, and the other movable swing arm is rotatably connected to the robot head. This application can solve the problems of the existing chin structure adjustment method being singular and having low positioning accuracy, realizing dual automatic and manual adjustment of the chin and precise positioning.

Description

Technical Field

[0001] This application relates to the field of bionic robots, and in particular to a mandibular combination adjustment mechanism and a bionic robot. Background Technology

[0002] In the field of bionic robot research and development, the realism of head movements is key to improving the robot's interactive experience, and the chin, as a core component of head expressions and movements, directly affects the overall bionic effect in terms of its mobility.

[0003] Existing bionic robot chin structures have significant limitations: some structures only support automatic rotation driven by motors, unable to be manually adjusted in the event of power failure or special scenarios; some manually adjustable structures lack precise angle positioning, making them prone to loosening or angle deviation; furthermore, the connection between the chin and head often uses a single transmission method, resulting in poor activity stability and a limited angle range, making it difficult to meet the needs for flexible chin adjustment in complex interaction scenarios. In addition, most robot head drive mechanisms have weak linkage with chin movement, and head swinging, rotation, and chin movements cannot be coordinated, further reducing the bionic simulation level. Therefore, there is an urgent need for a combined chin adjustment mechanism that combines automatic rotation and manual adjustment, precise positioning, and coordination with head movements. Utility Model Content

[0004] In view of the aforementioned problems, this application is made in order to provide a mandibular combination adjustment mechanism and a bionic robot that overcomes or at least partially solves the aforementioned problems, thereby solving the problems of existing mandibular structure adjustment methods being singular, having low positioning accuracy, and poor coordination with head movements, and realizing automatic and manual dual adjustment of the mandibular structure, precise positioning, and coordinated linkage between head and mandibular movements.

[0005] A mandibular combination adjustment mechanism, comprising:

[0006] Chin frame;

[0007] Two sets of ball bearing adjustment mechanisms are respectively connected to both ends of the chin frame; each ball bearing adjustment mechanism includes a mounting plate and an elastic ball bearing, one end of the mounting plate is provided with a plurality of recessed holes distributed in a ring, and the elastic ball bearing is elastically connected to the corresponding end sidewall of the chin frame; the end of the chin frame is hinged to one end of the mounting plate, so that when the chin frame rotates around the hinge point, the elastic ball bearing can be embedded in the corresponding recessed hole.

[0008] Two movable arms are respectively connected to the ends of the two mounting plates away from the chin skeleton; one of the movable arms is connected to the robot head via a drive assembly, and the other movable arm is rotatably connected to the robot head.

[0009] Optionally, the chin skeleton includes a connecting rod adapted to the contour of a human chin, the two ends of which are constructed as flat plate-like structures.

[0010] Optionally, the mounting plate has a rotation space at one end near the connecting rod, and the end of the connecting rod is accommodated in the rotation space and hinged to the mounting plate by a pin.

[0011] Optionally, a connecting plate extends along one side of the movable swing arm near the mounting plate, and one side wall of the mounting plate is in close contact with the side wall of the connecting plate and is fixedly connected to the connecting plate by a connector; the end of the movable swing arm that abuts against the mounting plate has a matching arc profile.

[0012] Optionally, the mounting plate includes two oppositely arranged outer plates and an inner plate sandwiched between one end of the two outer plates, wherein the length of the inner plate is less than the length of the outer plates, so that the rotation space is formed between the other ends of the two outer plates.

[0013] Optionally, the number of the holes is 7-9, and the arc length of their annular distribution is less than or equal to 1 / 2 of a circular arc.

[0014] Optionally, the drive assembly includes a motor, a gear transmission component, and a bearing. The motor is mounted on the end of a corresponding movable swing arm, the bearing is rotatably mounted on the robot head, and the output shaft of the motor is connected to the bearing via the gear transmission component.

[0015] Optionally, one end of the movable swing arm equipped with the motor is integrally formed with a support base, and the top two ends of the support base are provided with limit blocks, and the motor is installed between the two limit blocks.

[0016] A biomimetic robot includes a head structure and a mandibular assembly adjustment mechanism, the mandibular assembly adjustment mechanism being mounted on the head structure.

[0017] Optionally, a head driving mechanism is provided below the head structure, the head driving mechanism comprising:

[0018] The swing assembly includes a swing motor having two output shafts, the two output shafts being respectively connected to a swing frame, the swing frame being connected to the bottom of the head structure;

[0019] A rotating assembly includes a rotary motor disposed below the oscillating motor, the output shaft of the rotary motor being connected to a rotating frame, and the oscillating motor being mounted on the rotating frame.

[0020] This application has the following advantages:

[0021] In the embodiments of this application, a chin skeleton is used; two sets of ball bearing adjustment mechanisms are respectively connected to both ends of the chin skeleton; each ball bearing adjustment mechanism includes a mounting plate and an elastic ball bearing, one end of the mounting plate is provided with multiple recessed holes distributed in a ring, and the elastic ball bearing is elastically connected to the corresponding end sidewall of the chin skeleton; the end of the chin skeleton is hinged to one end of the mounting plate, so that when the chin skeleton rotates around the hinge point, the elastic ball bearing can be embedded in the corresponding recessed hole; two movable swing arms are respectively connected to the ends of the two mounting plates away from the chin skeleton; one of the movable swing arms is connected to the robot head via a drive assembly, and the other movable swing arm is rotatably connected to the robot head. By connecting the chin skeleton to the movable swing arms through the ball bearing adjustment mechanisms, the chin skeleton can be manually rotated freely around the hinge point. When rotating, the elastic ball bearing can be embedded in different recessed holes under elastic action to achieve precise angle locking; by setting a drive assembly at the end of one movable swing arm and connecting it to the robot head, and rotatably connecting the other movable swing arm to the robot head, power can be provided for automatic chin rotation, realizing automatic chin rotation. This application can solve the problems of the existing chin structure adjustment method being singular and having low positioning accuracy, and can realize the dual adjustment of the chin by both automatic and manual means, and precise positioning. Attached Figure Description

[0022] To more clearly illustrate the technical solution of this application, the drawings used in the description of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of a mandibular combination adjustment mechanism provided in one embodiment of this application;

[0024] Figure 2 This is a partial structural schematic diagram of a mandibular combination adjustment mechanism provided in one embodiment of this application;

[0025] Figure 3 This is a schematic diagram of the head structure of a bionic robot provided in one embodiment of this application.

[0026] Reference numerals: 1. Chin frame; 2. Ball bearing adjustment mechanism; 21. Mounting plate; 211. Embedded hole; 22. Elastic ball bearing; 23. Pin shaft; 3. Movable swing arm; 31. Connecting plate; 32. Bearing seat; 33. Limiting block; 4. Drive assembly; 5. Head structure; 51. Swing motor; 52. Swing frame; 53. Rotary motor; 54. Rotary frame. Detailed Implementation

[0027] To make the objectives, features, and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0028] Reference Figures 1 to 3 This illustration shows a jaw adjustment mechanism provided in an embodiment of this application, comprising a chin frame 1, two sets of ball-bearing adjustment mechanisms 2, and two movable rocker arms 3. The chin frame 1 serves as the core support, providing the basic shape for the chin. The two sets of ball-bearing adjustment mechanisms 2 are symmetrically connected to both ends of the chin frame 1. Each mechanism includes a mounting plate 21 and elastic balls 22. One end of the mounting plate 21 has multiple annularly distributed insertion holes 211. The elastic balls 22 are connected to the corresponding end sidewall of the chin frame 1 through an elastic element (such as a spring), and the end of the chin frame 1 is hinged to one end of the mounting plate 21. This hinge design allows the chin frame 1 to rotate freely around the hinge point. During rotation, the elastic balls 22 can be inserted into different insertion holes 211 under elastic action, achieving precise angle locking. The two movable rocker arms 3 are respectively connected to the end of the mounting plate 21 away from the chin frame 1. One movable rocker arm 3 is connected to the robot head through a drive assembly 4 to provide power for the automatic rotation of the chin, while the other movable rocker arm 3 is directly connected to the rotating part of the robot head.

[0029] This structure overcomes the limitations of traditional single-mode adjustment. When the drive component 4 is working, it can drive the movable swing arm 3, the mounting plate 21, and the chin frame 1 in a coordinated manner, enabling automatic rotation of the chin. When manual adjustment is required, force is directly applied to the chin frame 1, and the elastic ball 22 can overcome the elastic force to disengage from the current recess 211, rotate to the target angle, and then re-enter the recess 211 for positioning. This eliminates the need for the drive component 4, truly achieving both automatic and manual adjustment. Simultaneously, the cooperation between the annular recess 211 and the elastic ball 22 avoids the problem of angle deviation after manual adjustment, improving adjustment accuracy. The symmetrical design of the two movable swing arms 3 ensures balanced force during chin movement, preventing structural deformation or jamming caused by unilateral force.

[0030] Furthermore, the aforementioned elastic ball 22 is a steel ball, which is elastically connected to the chin skeleton 1 through an elastic element. The steel ball has high hardness and strong dimensional stability, and can maintain a precise fit with the hole 211 for a long time, avoiding positioning displacement caused by aging and wear of the elastic material, and significantly improving adjustment accuracy and structural durability.

[0031] As an example, the aforementioned chin skeleton 1 adopts a connecting rod structure that adapts to the contour of a human chin, and both ends of the connecting rod and the entire structure can be designed as flat plates. The connecting rod that adapts to the contour of a human face can highly replicate the shape of a human chin, significantly improving the biomimicry of the robot's appearance and avoiding the stiffness of traditional straight rod skeletons; the flat plate-shaped end structure increases the contact area with the mounting plate 21, which on the one hand facilitates stable hinged connection through components such as pins 23, reducing stress concentration at the hinge point, and on the other hand reduces the difficulty of end processing, ensuring precise adaptation to the rotation space of the mounting plate 21, further improving the smoothness of chin rotation.

[0032] As an example, the mounting plate 21 has a reserved rotation space at one end near the connecting rod. The end of the connecting rod is completely accommodated within this rotation space and is hinged to the mounting plate 21 via a pin 23. This rotation space provides ample room for movement at the end of the connecting rod, effectively preventing collisions or interference between the connecting rod and the mounting plate 21 during chin rotation, ensuring unrestricted rotation angles. The pin 23 hinge method offers high transmission efficiency and low frictional resistance, reducing jamming during chin rotation. Furthermore, the pin 23 connection structure is simple, easy to assemble and disassemble, and facilitates later maintenance and adjustment. In addition, the wrapping design of the rotation space around the connecting rod enhances the structural strength of the hinge, preventing loosening of the connection due to long-term rotation.

[0033] As an example, the movable rocker arm 3 extends along the side of the mounting plate 21 to form a connecting plate 31. The sidewall of the mounting plate 21 fits tightly against the sidewall of the connecting plate 31 and is fixed by connectors (such as bolts or rivets). The ends of the movable rocker arm 3 that abut against the mounting plate 21 feature a matching arc-shaped profile. The design of the connecting plate 31 increases the connection area between the movable rocker arm 3 and the mounting plate 21. Combined with the connectors, this effectively improves the connection strength, preventing loosening or displacement during long-term transmission, and allows for preliminary adjustment of the mounting angle of the chin frame 1 according to actual needs. The arc-shaped profile ensures a tighter fit, eliminating stress concentration issues caused by right-angle connections, extending the structural lifespan, reducing dust and other impurities from entering the connection gaps, reducing structural wear, and ensuring transmission stability.

[0034] As an example, the aforementioned mounting plate 21 consists of two relatively parallel outer plates and an inner plate sandwiched between one end of the two outer plates. The inner plate is shorter than the outer plate, so that the other end of the two outer plates naturally forms the aforementioned rotation space. This layered structure gives the mounting plate 21 good symmetry, and the two outer plates can evenly bear the torque generated when the chin rotates, preventing deformation caused by excessive force on one side of the outer plate; the inner plate plays a supporting and positioning role, ensuring that the distance between the two outer plates is consistent, and avoiding the influence of the rotation space size deviation on the rotation of the connecting rod; at the same time, the layered structure is easy to process and form, and the dimensions of the outer and inner plates can be precisely controlled by stamping or cutting processes to ensure the fitting accuracy of the rotation space and the end of the connecting rod, further improving the smoothness of the chin's movement; and it is also easy to disassemble and assemble the chin frame 1.

[0035] As an example, the number of the aforementioned recessed holes 211 is set to 7-9, and the arc length of the circular distribution does not exceed 1 / 2 of a circular arc. The selection of 7-9 recessed holes 211 satisfies the adjustment needs of different chin postures (such as slightly open, half-open, and fully open), achieving 7-9 adjustment levels while ensuring adjustment accuracy. It also avoids the problem of reduced strength of the mounting plate 21 due to too many recessed holes 211. Limiting the arc length to 1 / 2 of a circular arc conforms to the natural range of motion of the human chin (the maximum rotation angle of the human chin is usually no more than 90°), preventing excessive chin rotation that could cause structural damage or distortion of the biomimetic effect. It also prevents the elastic ball bearing 22 from deviating from the circular trajectory due to excessive rotation angle, ensuring reliable positioning.

[0036] As an example, the aforementioned drive component 4 includes a motor, gear transmission components, and bearings. The motor is fixed to the end of the corresponding movable swing arm 3, and the bearing is rotatably mounted on the robot head. The motor output shaft is connected to the bearing via the gear transmission components. The motor provides stable power for the automatic rotation of the chin, and the gear transmission components (such as spur gear sets or bevel gear sets) enable precise power transmission, avoiding slippage or delay problems that are prone to occur in belt drives, thus ensuring the controllability of the chin's rotation angle and speed. The bearing reduces the frictional resistance between the movable swing arm 3 and the robot head, lowers operating noise, and also supports the movable swing arm 3, preventing it from tilting during transmission and ensuring the stability of the chin's movement. In addition, this drive structure is compact, suitable for the limited installation space in the robot head, and easy to integrate with other components.

[0037] Understandably, the aforementioned motor can be an integrated structure that combines the motor and the reduction gear. The motor is the power output source, and the reduction gear is directly connected to the output end of the motor. It can achieve speed reduction and torque amplification without additional connecting parts, and the two form an inseparable whole drive component.

[0038] In one specific embodiment, the motor is a miniature DC motor, model GM12-370, voltage 12V, speed 150rpm; the gear transmission component is a spur gear set with a module of 0.5 and a transmission ratio of 1:3 to increase torque; the bearing is a deep groove ball bearing, model 608ZZ, with an inner diameter of 8mm and an outer diameter of 22mm.

[0039] As an example, the movable swing arm 3 for mounting the motor has an integrally formed support base 32 at one end. Limiting blocks 33 are set at both ends of the top of the support base 32, and the motor is fixed between the two limiting blocks 33. The integrally formed support base 32 has high strength and can stably support the weight of the motor, preventing vibrations generated during motor operation from causing misalignment in the installation position. The limiting blocks 33 can precisely position the motor, preventing lateral movement during operation and ensuring alignment between the motor output shaft and the gear transmission components, avoiding transmission jamming or component wear due to shaft misalignment. Simultaneously, the design of the support base 32 and limiting blocks 33 simplifies the motor installation process, eliminating the need for additional fixing brackets and reducing assembly difficulty and cost.

[0040] Based on the same concept, some embodiments of this application also disclose a bionic robot, which includes a head structure 5 and the aforementioned mandible adjustment mechanism, the mandible adjustment mechanism being installed at the corresponding position of the chin on the head structure 5. By combining the mandible adjustment mechanism, which has both automatic and manual adjustment functions, with the head structure 5, the robot head not only possesses a highly realistic appearance but also achieves more durable and precise flexible adjustment of the chin. In automatic interaction scenarios (such as mouth-opening movements during voice dialogue), the drive component 4 drives the chin to rotate automatically, with the steel ball ensuring accurate positioning without deviation each time. In scenarios requiring fine-tuning or power outages, when manually adjusting the chin, the smooth surface and high strength of the steel ball provide a smoother adjustment feel, and it maintains stable performance even after long-term use, significantly improving the robot's adaptability and lifespan. Simultaneously, the stable cooperation between the steel ball and the recess 211 ensures the chin remains stable in different postures, avoiding posture deviations caused by vibration, temperature changes, and other factors, further enhancing the bionic effect.

[0041] Furthermore, the aforementioned head structure 5 may include eye structures and other structures such as internal control systems.

[0042] As an example, a head drive mechanism is provided below the head structure 5, which includes a swing component and a rotation component. In the swing component, the swing motor 51 adopts a dual-output shaft design, with each output shaft connected to the swing frame 52, which is fixed to the bottom of the head structure 5. In the rotation component, the rotation motor 53 is located below the swing motor 51, with its output shaft connected to the rotation frame 54, and the swing motor 51 is mounted on the rotation frame 54. The dual-output shaft swing motor 51 ensures that the swing frame 52 is evenly stressed, driving the head structure 5 to smoothly swing left and right (such as "head shaking"), avoiding swing deviation caused by a single-sided output shaft; the rotation motor 53 drives the swing motor 51 to rotate together with the head structure 5 through the rotation frame 54, realizing head nodding or 360° rotation.

[0043] The head drive mechanism and the jaw adjustment mechanism form a more stable linkage: when the head swings left and right or nods up and down, the chin needs to frequently adjust its posture. The steel ball can quickly respond and embed into the corresponding hole 211, and its high strength characteristics can withstand the additional torque generated during the head linkage process, avoiding damage to the elastic ball 22 due to excessive torque. This ensures the long-term stability of the coordinated movement of the head and chin, solves the problem of the traditional robot's head and chin movements being disconnected and easily damaged, and significantly improves the overall biomimetic simulation degree and structural durability.

[0044] In one specific embodiment, the swing motor 51 is a dual-output shaft stepper motor, model 28BYJ-48, with a step angle of 5.625° / 64°; the rotary motor 53 is a stepper motor of the same model, which can receive pulse signals from the control system to achieve high-precision control of rotation angle, speed and direction, thereby achieving precise control of head swing and rotation angle, significantly improving the bionic effect.

[0045] The working process of this application embodiment:

[0046] When the robot needs to automatically control its chin movements (such as voice interaction), the controller sends a signal to the motor in the drive component 4. The motor starts and drives the movable swing arm 3 to rotate through the gear transmission component. The movable swing arm 3 drives the chin frame 1 to rotate synchronously, realizing the opening and closing of the mouth. When the chin posture needs to be manually adjusted (such as when power is off or fine-tuning), force is applied directly to the chin frame 1 by hand. The steel ball overcomes the spring force and disengages from the current insertion hole 211. Because the steel ball has high hardness and no elastic deformation, the force application process is uniform and without any sticking. After rotating the chin to the target angle, the hand is released, and the steel ball instantly embeds into the corresponding insertion hole 211 under the action of the spring. The positioning accuracy can reach ±0.5°, which is convenient and more accurate.

[0047] When the robot needs to move its head, the controller sends a signal to the head drive mechanism: the swing motor 51 starts, and the dual output shafts drive the swing frame 52 to swing up and down, which in turn drives the head structure 5 to nod up and down. The rotary motor 53 starts, driving the rotary frame 54, the swing motor 51 and the head structure 5 to rotate together, realizing the left and right rotation of the head, and the chin can make a slight opening movement in sync.

[0048] Although preferred embodiments of the present application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present application.

[0049] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0050] The above provides a detailed description of a mandibular combination adjustment mechanism provided in this application. Specific examples have been used to illustrate the principle and implementation of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​this application. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A mandibular combination adjustment mechanism, characterized in that, include: Chin frame (1); Two sets of ball adjustment mechanisms (2) are respectively connected to the two ends of the chin frame (1); each ball adjustment mechanism (2) includes a mounting plate (21) and an elastic ball (22). One end of the mounting plate (21) is provided with a plurality of recessed holes (211) distributed in a ring. The elastic ball (22) is elastically connected to the corresponding end sidewall of the chin frame (1). The end of the chin frame (1) is hinged to one end of the mounting plate (21), so that when the chin frame (1) rotates around the hinge point, the elastic ball (22) can be embedded in the corresponding recessed hole (211). Two movable arms (3) are respectively connected to one end of the two mounting plates (21) away from the chin skeleton (1); one of the movable arms (3) is connected to the robot head via a drive assembly (4), and the other movable arm (3) is rotatably connected to the robot head.

2. The mandibular combination adjustment mechanism according to claim 1, characterized in that, The chin skeleton (1) includes a connecting rod adapted to the contour of the human chin, and the two ends of the connecting rod are constructed as flat plate-like structures.

3. The mandibular combination adjustment mechanism according to claim 2, characterized in that, The mounting plate (21) has a rotation space at one end near the connecting rod. The end of the connecting rod is accommodated in the rotation space and is hinged to the mounting plate (21) by a pin (23).

4. The mandibular combination adjustment mechanism according to claim 1, characterized in that, The movable swing arm (3) has a connecting plate (31) extending along one side of the end near the mounting plate (21). One side wall of the mounting plate (21) is in close contact with the side wall of the connecting plate (31) and is fixedly connected to the connecting plate (31) through a connector. The ends of the movable swing arm (3) that abut against the mounting plate (21) have a matching arc profile.

5. The mandibular combination adjustment mechanism according to claim 3, characterized in that, The mounting plate (21) includes two oppositely arranged outer plates and an inner plate sandwiched between one end of the two plates. The length of the inner plate is less than the length of the outer plates, so that the rotation space is formed between the other ends of the two outer plates.

6. The mandibular combination adjustment mechanism according to claim 1, characterized in that, The number of the piers (211) is 7-9, and the arc length of their annular distribution is less than or equal to 1 / 2 of a circular arc.

7. The mandibular combination adjustment mechanism according to claim 1, characterized in that, The drive assembly (4) includes a motor, a gear transmission component and a bearing. The motor is installed at the end of the corresponding movable swing arm (3), and the bearing is rotatably mounted on the robot head. The output shaft of the motor is connected to the bearing through the gear transmission component.

8. The mandibular combination adjustment mechanism according to claim 7, characterized in that, One end of the movable swing arm (3) equipped with a motor is integrally formed with a support seat (32), and the top two ends of the support seat (32) are provided with limit blocks (33), and the motor is installed between the two limit blocks (33).

9. A biomimetic robot, characterized in that, The bionic robot includes a head structure (5) and a mandibular combination adjustment mechanism as described in any one of claims 1 to 8, the mandibular combination adjustment mechanism being mounted on the head structure (5).

10. The bionic robot according to claim 9, characterized in that, A head driving mechanism is provided below the head structure (5), and the head driving mechanism includes: The swing assembly includes a swing motor (51) having two output shafts, the two output shafts being connected to a swing frame (52) for transmission, the swing frame (52) being connected to the bottom of the head structure (5); The rotating assembly includes a rotating motor (53) disposed below the swing motor (51), the output shaft of the rotating motor (53) being connected to a rotating frame (54), and the swing motor (51) being mounted on the rotating frame (54).

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