Three-degree-of-freedom joint structure and machine dinosaur neck skeleton

Abstract

The application relates to the field of bionic robots, and particularly discloses a three-degree-of-freedom joint structure, which comprises a main shaft provided with a first ball gear, a seat body provided with a first driving motor and an assisting motor, a gear set, a damping assembly, a first spring connecting seat, a second spring connecting seat, a movable frame, an auxiliary frame set provided with a rotating ring, a limiting assembly, a first steering driving set, a second steering driving set and a robot dinosaur neck skeleton provided with the joint structure. The first driving motor is used for realizing the axial rotation of the main shaft, the first steering driving set and the second steering driving set are combined to enable the dinosaur head to swing in the lateral direction, the flexibility is high, the response speed is fast, the limiting assembly capable of limiting the relative rotation of the first shaft sleeve and the second shaft sleeve is arranged on the auxiliary frame set, the torsion transmission can be realized in a higher-intensity mode, the mechanism is simple and ingenious, and the cost and weight can be greatly reduced.

Description

Technical Field

[0001] This invention belongs to the field of biomimetic robots, and specifically relates to a three-degree-of-freedom joint structure and a robotic dinosaur neck skeleton. Background Technology

[0002] Robotics technology has been widely applied in all aspects of modern life and various industries. Technicians have also invented many biomimetic robots based on the movement and walking patterns of animals in nature to solve problems in production and daily life. Some biomimetic robots are used in fields such as educational tools and film props, therefore, the requirements for their flexibility and realism are relatively high.

[0003] Dinosaur bionic robots are frequently used in natural science teaching aids and exhibitions. Real dinosaurs have a high degree of freedom and flexibility in turning their heads and necks. When designing the neck joints of robotic dinosaurs, it is necessary to consider the issues of multi-degree-of-freedom linkage and response speed, and also to maximize the lightweight of the rotating joints. Therefore, when designing the rotating joints of dinosaur head and neck robots, how to improve their flexibility and response speed while taking into account lightweight design is the main direction considered by the engineers and also an important challenge they face.

[0004] Patent application CN201621105393.3 discloses an involute ball gear mechanical joint, comprising a pair of involute ball gears, an inner ball gear support, an outer ball gear support, a ball hinge support, a through-type linear screw stepper motor, a support arm, and a U-shaped bracket. The pair of involute ball gears are located inside the inner ball gear support; the inner ball gear support is located inside the outer ball gear support; the U-shaped bracket is located on the support arm; and the ball hinge support is located on the outer ball gear support. This mechanical joint in the prior art has two degrees of freedom for transmission. The tooth rings of the involute ball gears are distributed on the spherical caps. The motion characteristic is that a pair of ball joints perform pure rolling motion. By transforming the motion between the two spherical surfaces, a precise constant transmission ratio spherical motion of the pair of balls can be achieved. However, firstly, the mechanical joint in this prior art only has two degrees of freedom, making rotation impossible and lacking flexibility. Furthermore, it is driven by a screw motor, resulting in a slow response speed.

[0005] Patent application CN201920109428.8 discloses a flexible robotic arm based on ball gear transmission. It includes an end effector, an arm extension unit, an actuator control unit, an arm extension control unit, and a support. The end effector shaft is connected to one end of the arm extension unit, and the other end of the arm extension unit is connected to the actuator control unit. The arm extension control unit is fixed to both sides of the other end of the arm extension unit. The support is used to fix and support the actuator control unit and the arm extension control unit. Although the robotic arm in this prior art uses ball gear transmission, increasing its flexibility and facilitating exploration, it can only achieve two degrees of freedom: rotation and unidirectional swing. Furthermore, its rotational torque must be transmitted through the meshing of the teeth of the involute spherical gears, resulting in a complex tooth structure, high cost, low strength, and inability to achieve flexible rotation with multiple degrees of freedom.

[0006] The above background information is provided only to aid in understanding the inventive concept and technical solution of this invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this patent application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0007] The purpose of this invention is to provide a three-degree-of-freedom joint structure and a robotic dinosaur neck skeleton, thereby overcoming the shortcomings of existing ball-tooth drive joints and dinosaur bionic robots, such as slow joint movement response speed, low flexibility, low strength, and complex structure and high manufacturing cost.

[0008] To achieve the above objectives, the present invention provides a three-degree-of-freedom joint structure, characterized in that it comprises: a main shaft, one end of which is provided with a first ball gear, and a first bushing in the middle of the main shaft; a base, on which a first drive motor is provided, the other end of the main shaft being rotatably connected to the base and coaxially connected to the output end of the first drive motor, the first drive motor being capable of driving the main shaft to rotate around its axis; a movable frame, one end of which is provided with a second ball gear, the second ball gear meshing with the first ball gear; and an auxiliary frame assembly, which is sleeved on the outer periphery of the main shaft, one end of which is provided with a second bushing, the second bushing being sleeved on the outer periphery of the first bushing in a spherical connection manner, and a limiting component being provided between the second bushing and the first bushing, the limiting component being capable of restricting the second bushing. The auxiliary frame assembly has a rotatable rotating ring fitted around one end of its outer periphery relative to the first bushing in the axial direction. The other end of the auxiliary frame assembly is connected to the middle of the movable frame via a cross shaft. The rotating ring has a first connecting part and a second connecting part on its outer periphery. The quadrant angles of the first connecting part and the second connecting part differ by 90 degrees. A first steering drive group and a second steering drive group are mounted on the base. The first steering drive group includes a first push rod, one end of which can move along the axial direction of the main shaft and is connected to the first connecting part by a spherical hinge. The second steering drive group includes a second push rod, one end of which can move along the axial direction of the main shaft and is connected to the second connecting part by a spherical hinge.

[0009] Preferably, in the above technical solution, the limiting component includes a mutually matching limiting groove and a limiting pin. The limiting groove is disposed on either the first bushing or the second bushing, and the limiting pin is disposed on the other of the first bushing and the second bushing. The limiting groove is disposed along the axial direction of the first bushing, and the limiting pin is capable of sliding within the limiting groove.

[0010] Preferably, in the above technical solution, the limiting component is located between the first connecting portion and the second connecting portion, and the first connecting portion and the second connecting portion are symmetrically arranged with the limiting component as the center.

[0011] Preferably, the above technical solution further includes an assist motor, which is mounted on the seat. The output shaft of the assist motor is connected to the output shaft of the first drive motor via a gear set. The gear set includes a first gear and a second gear that mesh with each other. The first gear is coaxially connected to the output shaft of the assist motor, and the second gear is coaxially connected to the output shaft of the first drive motor.

[0012] Preferably, in the above technical solution, the first gear is connected to the output shaft of the power assist motor via a damping assembly. The damping assembly includes: a first connecting plate, which is fixedly connected to the output shaft of the power assist motor; a second connecting plate, which is fixedly connected to the first connecting plate; a damping shaft, one end of which is inserted into the second connecting plate and can rotate synchronously with the second connecting plate, the damping shaft having a locking part that restricts axial movement between the damping shaft and the second connecting plate; a slip plate, which is rotatably sleeved on the damping shaft, and the first gear is fixedly connected to the slip plate; a spacer, which is sleeved on the damping shaft and located between the slip plate and the second connecting plate; and a damping nut, which is threadedly connected to the other end of the damping shaft, and a spring washer is provided between the damping nut and the slip plate, so that when the damping nut is tightened, the spring washer can be pressed against the slip plate.

[0013] Preferably, in the above technical solution, the damping component further includes two shims, which are sleeved on the damping shaft and the slip plate is located between the two shims. The shims can rotate synchronously with the damping shaft.

[0014] Preferably, the above technical solution further includes a reinforcing arm assembly, which includes: a first connecting seat, which is fixedly connected to the seat body, and the first connecting seat is opposite to either the first connecting part or the second connecting part; a second connecting seat, one end of which is rotatably connected to the outer periphery of the rotating ring; and a swing rod, the middle part of which is bendable, one end of which is rotatably connected to the first connecting seat, and the other end of which is rotatably connected to the other end of the second connecting seat, wherein the rotation axes of the rotating parts on the swing rod are parallel to each other.

[0015] Preferably, the above technical solution further includes: a first spring fixing seat, which is fixedly disposed on the seat body and has a plurality of first spring fixing holes; and a second spring fixing seat, which is fixedly disposed on the outer periphery of the rotating ring and has a plurality of second spring fixing holes, the number of the second spring fixing holes being less than the number of the first spring fixing holes.

[0016] Preferably, in the above technical solution, the first steering drive group further includes a first servo motor, which is fixedly mounted on the base. The output end of the first servo motor is provided with a rotatable first swing arm, and the swing end of the first swing arm is spherically hinged to the other end of the first push rod. The distance between the two ends of the first push rod is adjustable. The second steering drive group further includes a second servo motor, which is fixedly mounted on the base. The output end of the second servo motor is provided with a rotatable second swing arm, and the swing end of the second swing arm is spherically hinged to the other end of the second push rod. The distance between the two ends of the second push rod is adjustable.

[0017] On the other hand, to achieve the above objectives, the present invention also provides a dinosaur neck skeleton, which includes the above-mentioned three-degree-of-freedom joint structure and a head mounting frame. The head mounting frame is fixedly connected to the other end of the movable frame. A third servo motor is symmetrically arranged on both sides of the head mounting frame. The auxiliary frame assembly includes a connecting frame and a support frame. The connecting frame has a sleeve hole, and the second bushing is fixedly fitted in the sleeve hole. A first bearing is provided on the outer periphery of the connecting frame, and the rotating ring is fitted on the first bearing. A connecting ring is provided at one end of the support frame, and the connecting ring is fixedly connected to the connecting frame. A support ring is provided in the middle of the support frame, and the main shaft passes through the support ring. One end of the support ring is connected to the connecting ring through several connecting ribs. The other end of the support ring has two outwardly extending connecting arms, and the connecting arms are rotatably connected to the cross shaft. The diameter of the support ring is larger than the diameter of the connecting ring.

[0018] Compared with existing technologies, the present invention has the following advantages:

[0019] 1. The three-degree-of-freedom joint structure in this invention can achieve axial rotation of the main shaft through the first drive motor. Through the combined action of the first steering drive group and the second steering drive group, the movable frame can form a lateral swing in the circumferential direction. It is not only highly flexible but also has a fast response speed. The auxiliary frame group is provided with a limiting component that can restrict the relative rotation of the first bushing and the second bushing. It can not only transmit torque in a stronger way, but also make the mechanism simpler and more ingenious, which can significantly reduce cost and weight.

[0020] 2. In this invention, the main shaft and the auxiliary frame assembly are connected by a first bushing and a second bushing in a spherical connection, thereby enabling the auxiliary frame assembly and the main shaft to rotate in all directions. A limiting component consisting of a limiting groove and a limiting pin is provided between the first bushing and the second bushing. The direction of the limiting groove is consistent with the axial direction of the first bushing. When the main shaft rotates, it can drive the auxiliary frame assembly to rotate synchronously, realizing the movement in rotational freedom in a simple and reliable manner.

[0021] 3. The limiting component in this invention is located between the first connecting part and the second connecting part, and the difference in the limiting angle between them is 45 degrees. Therefore, when the first steering drive group and the second steering drive group push the auxiliary frame group to swing in the left and right and up and down directions, it will be relatively smooth and there will be no jamming. Furthermore, when swinging in the two directions, the angle deviation generated by the limiting component is relatively small. The above deviation can be compensated by a slight rotation of the first drive motor, thereby making the compensation accuracy more precise and the compensation speed faster.

[0022] 4. The assist motor in this invention can accurately position the steering angle of the first drive motor, and the damping component can reduce the rotation speed of the first drive motor and the assist motor, thereby making the positioning more accurate.

[0023] 5. The slip plate in the damping assembly of the present invention is used to install the first gear, and a certain damping can be applied to the slip plate through the damping nut and the spring washer. When the torque on the first gear is too large, the slip plate can slip, thereby providing a certain torque protection for the power assist motor. Furthermore, the magnitude of the damping force can be easily changed by changing the pressure position of the damping nut on the spring washer.

[0024] 6. The reinforcing arm assembly in this invention can enhance the connection strength between the auxiliary frame assembly and the base body. When the auxiliary frame assembly swings, the reinforcing arm assembly can bend and rotate with the swing of the auxiliary frame assembly, thereby forming a balancing mechanism with the first steering drive assembly and the second steering drive assembly.

[0025] 7. In this invention, a tension spring can be connected between the first spring fixing seat and the second spring fixing seat. When a heavy load-bearing structure is installed on the movable frame, it can assist in lifting when the joint is raised. Furthermore, the number of tension springs can be changed according to the specific weight of the load-bearing structure, thereby changing the magnitude of the auxiliary pulling force. It also helps to reduce the rated power of the servo motor in the steering drive group used for lifting, thus achieving energy saving and saving installation space.

[0026] 8. The first and second steering drive groups in this invention are both composed of a servo motor and a push rod with a ball hinge. Compared with the linear hydraulic cylinder or lead screw structure, the response speed is faster and the range of motion is larger. The distance between the two ends of the push rod can also be flexibly adjusted to meet different installation positions and application occasions.

[0027] 9. The third servo motor in the neck skeleton of the robotic dinosaur in this invention can be connected to the dinosaur's mandible, thereby driving the mandible to open and close. At the same time, a support ring with a large diameter is provided in the middle of the support frame, which not only supports the skin of the dinosaur's neck, but also serves to provide a contoured transition from the diameter of the dinosaur's neck to the diameter of the dinosaur's head. The connecting arm enables the support frame to form a cage-like frame structure, which not only provides contoured support, but also reduces the overall weight of the support frame. Attached Figure Description

[0028] Figure 1 This is a structural diagram of the three-degree-of-freedom joint structure in Embodiment 1.

[0029] Figure 2 This is a structural diagram of the three-degree-of-freedom joint structure in Embodiment 1 from another angle.

[0030] Figure 3 This is a partial sectional view of the spindle, base, and auxiliary frame assembly in Embodiment 1.

[0031] Figure 4 This is an exploded view of the first bushing, the second bushing, and the limiting component in Embodiment 1.

[0032] Figure 5 This is a partial cross-sectional view of the damping component in Embodiment 1.

[0033] Figure 6 This is a structural diagram of the reinforcing arm assembly in Embodiment 1.

[0034] Figure 7 This is a structural diagram of the neck skeleton of the robotic dinosaur in Example 2.

[0035] Figure 8 This is a structural diagram of the auxiliary frame assembly in Embodiment 2.

[0036] Explanation of key figure labels:

[0037] 100 - Main shaft, 101 - First ball gear, 102 - First bushing, 103 - Second bearing;

[0038] 200-Seat body, 201-First drive motor, 202-Assist motor, 210-Gear set, 211-First gear, 212-Second gear, 220-Damping assembly, 221-First connecting plate, 222-Second connecting plate, 223-Damping shaft, 224-Locking part, 225-Slip plate, 226-Spacer, 227-Damping nut, 228-Spring washer, 229-Washer, 230-Reinforced arm assembly, 231-First connecting seat, 232-Second connecting seat, 233-Swing rod, 240-First spring fixing seat, 241-First spring fixing hole, 250-Second spring fixing seat, 251-Second spring fixing hole;

[0039] 300 - Movable frame, 301 - Second ball gear;

[0040] 400-Auxiliary frame assembly, 401-Second bushing, 402-Rotating ring, 403-Cross shaft, 404-First connecting part, 405-Second connecting part, 410-Connecting frame, 411-Sleeve hole, 412-First bearing, 420-Support frame, 421-Connecting ring, 422-Supporting ring, 423-Connecting rib, 424-Connecting arm;

[0041] 500 - Limiting component, 501 - Limiting groove, 502 - Limiting pin;

[0042] 600 - First steering drive assembly, 601 - First push rod, 602 - First servo motor, 603 - First swing arm;

[0043] 700 - Second steering drive assembly, 701 - Second push rod, 702 - Second servo motor, 703 - Second swing arm;

[0044] 800 - Head mounting bracket, 801 - Third servo motor. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] In the description of this invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "top surface," "bottom surface," "inner," "outer," "inner side," and "outer side," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0047] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. Where the terms "first," "second," and "third" are used for descriptive purposes and to distinguish technical features, they should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the sequential relationship of the indicated technical features.

[0048] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The embodiments of this invention will now be described according to its overall structure. Example

[0049] like Figures 1 to 6As shown, the three-degree-of-freedom joint structure in this embodiment includes: a main shaft 100, a first ball gear 101, a first bushing 102, a second bearing 103, a base 200, a first drive motor 201, an assist motor 202, a gear set 210, a first gear 211, a second gear 212, a damping assembly 220, a first connecting plate 221, a second connecting plate 222, a damping shaft 223, a locking part 224, a slip plate 225, a spacer 226, a damping nut 227, a spring washer 228, a gasket 229, a reinforcing arm assembly 230, a first connecting seat 231, a second connecting seat 232, a swing arm 233, a first spring fixing seat 240, a first spring fixing hole 241, and a second spring... Spring fixing seat 250, second spring fixing hole 251, movable frame 300, second ball gear 301, auxiliary frame assembly 400, second bushing 401, rotating ring 402, cross shaft 403, first connecting part 404, second connecting part 405, connecting frame 410, sleeve hole 411, first bearing 412, support frame 420, connecting ring 421, support ring 422, connecting rib 423, connecting arm 424, limiting assembly 500, limiting groove 501, limiting pin 502, first steering drive assembly 600, first push rod 601, first servo motor 602, first swing arm 603, second steering drive assembly 700, second push rod 701, second servo motor 702, second swing arm 703.

[0050] The spindle 100 is a hollow cylindrical structure. A first ball gear 101 is bolted to one end face. The radius of the central region of the spindle 100 is larger than the radius of the end region, and a first bushing 102 is mounted on the outer periphery of the central region. The outer periphery of the first bushing 102 has an outwardly protruding first spherical surface. A first drive motor 201 is mounted on the base 200. The other end of the spindle 100 is rotatably connected to the base 200 via two parallel second bearings 103. The first drive motor 201 is coaxially connected to the output end of the first drive motor 201 via bolts. The first drive motor 201 can drive the main shaft 100 to rotate around its axis. The cross section of one end of the movable frame 300 is bolted with a second ball gear 301. The end faces of the second ball gear 301 and the first ball gear 101 can mesh with each other, and the meshing surfaces of the two are provided with ring teeth that are nested from the inside to the outside. The end face of the ring teeth is an involute tooth shape, and the tooth tip of the ring teeth of the ball gear forms a spherical arc surface that bulges outward from the center.

[0051] An auxiliary frame assembly 400 is fitted around the outer periphery of the main spindle 100. A second bushing 401 is installed at one end of the auxiliary frame assembly 400. The inner surface of the second bushing 401 is an inwardly concave second spherical surface that can cover the first spherical surface, thereby allowing the second bushing 401 to be fitted around the outer periphery of the first bushing 102 in a spherical connection manner. A limit assembly 500 is provided between the second bushing 401 and the first bushing 102. The limit assembly 500 includes a matching limit groove 501 and a limit... Pin 502 and limiting groove 501 are disposed on the second spherical surface of the second bushing 401, and limiting pin 502 is disposed on the first spherical surface of the first bushing 102. The limiting groove 501 is disposed along the axial direction of the first bushing 102 and adapts to the curvature of the second spherical surface. When the axes of the first bushing 102 and the second bushing 401 coincide and the second bushing 401 rotates along the axial direction, the limiting groove 501 can limit the limiting pin 502, so that the first bushing 102 can move with the second bushing. 401 rotate synchronously; when the first bushing 102 and the second bushing 401 rotate relative to each other and their axes form a certain angle, the limiting pin 502 can slide within the limiting groove 501; a rotatable rotating ring 402 is installed on the outer periphery of one end of the auxiliary frame assembly 400, and the other end of the auxiliary frame assembly 400 is connected to the middle of the movable frame 300 through a cross shaft 403. The outer periphery of the rotating ring 402 is provided with an outwardly protruding first connecting part 404 and a second connecting part 405. The connecting part 404 is on one side of the rotating ring 402, and the second connecting part 405 is at the bottom of the rotating ring 402. The quadrant angle of the first connecting part 404 on the rotating ring 402 and the quadrant angle of the second connecting part 405 on the rotating ring 402 differ by 90 degrees, that is, they are perpendicular to each other. The positions of the limiting groove 501 and the limiting pin 502 are exactly between the first connecting part 404 and the second connecting part 405, and the first connecting part 404 and the second connecting part 405 are symmetrically arranged with the limiting component 500 as the center.

[0052] In addition, an assist motor 202 is also installed on the seat 200. The output shaft of the assist motor 202 is connected to the output shaft of the first drive motor 201 through a gear set 210. The gear set 210 includes a first gear 211 and a second gear 212 that mesh with each other. The first gear 211 is coaxially connected to the output shaft of the assist motor 202 through a damping component 220, and the second gear 212 is coaxially connected to the output shaft of the first drive motor 201.

[0053] More specifically, the damping assembly 220 includes: a first connecting plate 221, a second connecting plate 222, a damping shaft 223, a slip plate 225, a spacer 226, a damping nut 227, and a washer 229; the first connecting plate 221 is fixedly connected to the output shaft of the power assist motor 202, the second connecting plate 222 is coaxially fixedly connected to the first connecting plate 221 by bolts, one end of the damping shaft 223 is inserted into the second connecting plate 222 and achieves synchronous rotation with the second connecting plate 222 through the planar structure on the shaft side, the end face of one end of the damping shaft 223 is provided with a locking part 224 with a stepped surface, the stepped surface on the locking part 224 can mutually limit the end face of the second connecting plate 222, thereby limiting the axial movement between the damping shaft 223 and the second connecting plate 222; the slip plate 225 is sleeved on the damping... The middle part of the shaft 223 is rotatable. The first gear 211 is fixedly connected to the slip plate 225 by bolts. The spacer 226 is sleeved on the damping shaft 223 and located between the slip plate 225 and the second connecting plate 222. The other end of the damping shaft 223 is threadedly connected to the damping nut 227. A spring washer 228 is installed between the damping nut 227 and the slip plate 225. There are two washers 229. The two washers 229 are sleeved on the damping shaft 223 at the same time and the slip plate 225 is sandwiched in the middle. One washer 229 abuts against the end of the spacer 226 and the other washer 229 abuts against the spring washer 228. When the damping nut 227 is tightened, the spring washer 228 can be pressed against the washer 229 on the slip plate 225 side, thereby applying a certain damping force to the slip plate 225.

[0054] A first steering drive assembly 600 and a second steering drive assembly 700 are installed between the base 200 and the auxiliary frame assembly 400. The first steering drive assembly 600 includes a first push rod 601, a first servo motor 602, and a first swing arm 603. The first servo motor 602 is fixedly installed on one side of the base 200, and its output end is fixedly connected to the connecting end of the first swing arm 603. One end of the first push rod 601 is connected to the first connecting part 404 by a spherical hinge, and the other end of the first push rod 601 is spherically hinged to the swing end of the first swing arm 603. When the first servo motor 602 rotates, it can drive the first connecting part 404 to move along the axis of the main shaft 100, thereby causing the auxiliary frame assembly 400 to move left and right. The distance between the two ends of the first push rod 601 is adjustable; the second steering drive assembly 700 includes a second push rod 701, a second servo motor 702, and a second swing arm 703. The second servo motor 702 is fixedly installed below the base 200. The output end of the second servo motor 702 is fixedly connected to the connecting end of the second swing arm 703. One end of the second push rod 701 is connected to the second connecting part 405 by a spherical hinge. The other end of the second push rod 701 is spherically hinged to the swing end of the second swing arm 703. When the second servo motor 702 rotates, it can drive the second connecting part to move along the axis of the main shaft 100, thereby causing the auxiliary frame assembly 400 to swing up and down. The distance between the two ends of the second push rod 701 is adjustable.

[0055] In addition, a reinforcing arm assembly 230 is installed between the seat 200 and the rotating ring 402. The reinforcing arm assembly 230 includes a first connecting seat 231, a second connecting seat 232, and a swing arm 233. The first connecting seat 231 is fixedly connected to the side of the seat 200, and one end of the second connecting seat 232 is fixedly connected to the other side of the rotating ring 402 and is positioned opposite to the first connecting part 404. The middle part of the swing arm 233 can be bent. One end of the swing arm 233 is rotatably connected to the first connecting seat 231, and the other end of the swing arm 233 is rotatably connected to the other end of the second connecting seat 232. The rotation axes of the middle part and both ends of the swing arm 233 are parallel to each other.

[0056] In addition, a second spring fixing seat 250 is provided above the rotating ring 402. The first spring fixing seat 240 has multiple first spring fixing holes 241. The first spring fixing seat 240 is provided above the seat body 200. The second spring fixing seat 250 has multiple second spring fixing holes 251. The number of second spring fixing holes 251 is less than the number of first spring fixing holes 241. The arrangement of the first spring fixing holes 241 and the second spring fixing holes 251 is an arc row arrangement. The first spring fixing holes 241 and the second spring fixing holes 251 are used to install tension springs. Example

[0057] like Figures 7 to 8As shown, the mechanical dinosaur neck skeleton in this embodiment includes the three-degree-of-freedom joint structure in the above embodiment, and also includes: a connecting frame 410, a sleeve hole 411, a first bearing 412, a support frame 420, a connecting ring 421, a support ring 422, a connecting rib 423, a connecting arm 424, a head mounting frame 800, and a third servo motor 801.

[0058] The head mounting bracket 800 is fixedly connected to the other end of the movable bracket 300. The head mounting bracket 800 has a pre-drilled mounting hole for mounting the head skeleton. A third servo motor 801 is symmetrically arranged on both sides below the head mounting bracket 800 to mount the mandible of the dinosaur head skeleton and drive the mandible to open and close. The auxiliary frame assembly 400 includes a connecting frame 410 and a support frame 420. The connecting frame 410 has a sleeve hole 411, and a second bushing 401 is fixedly installed in the sleeve hole 411. A first bearing 412 is installed on the outer periphery of the connecting frame 410, and a rotating ring 402 is fitted onto the first bearing 412. One end of the support frame 420 is provided with a connecting ring 421, which is fixedly connected to the connecting frame 410 by bolts. The middle part of the support frame 420 is provided with a support ring 422, through which the main shaft 100 passes. One end of the support ring 422 is connected to the connecting ring 421 by multiple connecting ribs 423. The other end of the support ring 422 is provided with two outwardly extending connecting arms 424, which are rotatably connected to the two shaft ends opposite to the cross shaft 403. The diameter of the support ring 422 is larger than that of the connecting ring 421, so that the support ring 422 as a whole forms a cage structure with a conical outer contour.

[0059] During operation, the first drive motor 201 can drive the main shaft 100 to rotate. When the main shaft 100 rotates, it can drive the connecting frame 410 in the auxiliary frame group 400 to rotate through the action of the limiting component 500. The torque is transmitted to the cross shaft 403 through the connecting arm 424, thereby driving the head mounting frame 800 to rotate, thus realizing the action of simulating the rotation of the dinosaur's head. Furthermore, the assist motor 202 can achieve the function of deceleration and torque increase, thereby ensuring the accurate positioning of the robotic dinosaur's neck skeleton during rotation.

[0060] The first servo motor 602 in the first steering drive group 600 drives the first swing arm 603 to rotate, which in turn drives the first push rod 601 to push and pull in the front and back directions, thereby driving the auxiliary frame group 400 to swing in the left and right directions. At this time, through the action of the cross shaft 403 and the two ball gear structures, the head mounting seat can also be linked in the left and right directions, so that the head of the robotic dinosaur can swing in the left and right directions.

[0061] The second servo motor 702 in the second steering drive assembly 700 drives the second swing arm 703 to rotate, which in turn drives the second push rod 701 to push and pull in the front and back directions, thereby driving the auxiliary frame assembly 400 to swing up and down. At this time, through the action of the cross shaft 403 and the two ball gear structures, the head mounting seat can also be linked in the up and down direction, so that the head of the robotic dinosaur can swing up and down. A tension spring is connected between the first spring fixing seat 240 and the second spring fixing seat 250 at the top of the neck skeleton, which can generate tension on the dinosaur's neck skeleton, thereby helping the robotic dinosaur's head to rise.

[0062] In summary, the three-degree-of-freedom joint structure of this invention enables the axial rotation of the main shaft 100 via the first drive motor 201. Through the combined action of the first steering drive group 600 and the second steering drive group 700, the movable frame 300 can achieve lateral swing in the circumferential direction, exhibiting not only high flexibility but also fast response. The auxiliary frame group 400 is equipped with a limiting component 500 that restricts the relative rotation of the first bushing 102 and the second bushing 401. This not only allows for torque transmission with higher strength but also results in a simpler and more ingenious mechanism. Significantly reducing costs and weight; the third servo 801 in the robotic dinosaur's neck skeleton can connect with the dinosaur's mandible, thereby driving the mandible to open and close; at the same time, a support ring 422 with a large diameter is also set in the middle of the support frame 420, which not only supports the skin of the dinosaur's neck, but also plays a role in the contour transition from the diameter of the dinosaur's neck to the diameter of the dinosaur's head; the connecting arm 424 enables the support frame 420 to form a cage-like frame structure, which not only plays a role in contour support, but also reduces the overall weight of the support frame 420.

[0063] The foregoing description of specific exemplary embodiments of the present invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it is obvious that many changes and variations can be made based on the above teachings. Although embodiments of the invention have been shown and described, these specific embodiments are merely explanations of the invention and are not intended to limit it. The specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. The purpose of selecting and describing exemplary embodiments is to explain the specific principles of the invention and its practical application, so that those skilled in the art, after reading this specification, can make modifications, substitutions, variations, and various choices and changes to the embodiments as needed without departing from the principles and spirit of the invention, provided that such modifications, substitutions, variations, and choices and changes are within the scope of the claims of the invention and are protected by patent law.

Claims

1. A three-degree-of-freedom joint structure, characterized in that, include: A main shaft, one end of which is provided with a first ball gear, and the middle part of the main shaft is provided with a first bushing, the outer periphery of which is provided with an outwardly protruding first spherical surface; A base is provided with a first drive motor. The other end of the main shaft is rotatably connected to the base and coaxially connected to the output end of the first drive motor. The first drive motor can drive the main shaft to rotate around its axis. A movable frame, one end of which is provided with a second ball gear, the second ball gear meshing with the first ball gear; An auxiliary frame assembly is sleeved on the outer periphery of the main shaft. One end of the auxiliary frame assembly has a second bushing. The inner surface of the second bushing is an inwardly concave second spherical surface. The second bushing is sleeved on the outer periphery of the first bushing via a spherical connection. A limiting component is provided between the second bushing and the first bushing. The limiting component includes a matching limiting groove and a limiting pin. The limiting groove is located on either the first spherical surface or the second spherical surface, and the limiting pin is located on the other spherical surface. The limiting groove is arranged along the axial direction of the first bushing. The pin can slide within the limiting groove; the limiting component can restrict the relative rotation of the second bushing and the first bushing in the axial direction; a rotatable rotating ring is fitted around the outer periphery of one end of the auxiliary frame assembly; the other end of the auxiliary frame assembly is connected to the middle of the movable frame through a cross shaft; a first connecting part and a second connecting part are provided around the outer periphery of the rotating ring; the quadrant angle of the first connecting part and the quadrant angle of the second connecting part differ by 90 degrees; the limiting component is located between the first connecting part and the second connecting part, and the first connecting part and the second connecting part are symmetrically arranged with the limiting component as the center; A first steering drive group and a second steering drive group are mounted on the base. The first steering drive group includes a first push rod, one end of which is movable along the axis of the main shaft and connected to the first connecting part by a spherical hinge. The second steering drive group includes a second push rod, one end of which is movable along the axis of the main shaft and connected to the second connecting part by a spherical hinge. The first steering drive group also includes a first servo motor, which is fixedly mounted on the base. The output end of the first servo motor is provided with a rotatable first swing arm, the swing end of which is spherically hinged to the other end of the first push rod. The distance between the two ends of the first push rod is adjustable. The second steering drive assembly also includes a second servo motor, which is fixedly mounted on the base. The output end of the second servo motor is provided with a rotatable second swing arm. The swing end of the second swing arm is spherically hinged to the other end of the second push rod. The distance between the two ends of the second push rod is adjustable.

2. The three-degree-of-freedom joint structure according to claim 1, characterized in that, It also includes an assist motor, which is mounted on the base. The output shaft of the assist motor is connected to the output shaft of the first drive motor via a gear set. The gear set includes a first gear and a second gear that mesh with each other. The first gear is coaxially connected to the output shaft of the assist motor, and the second gear is coaxially connected to the output shaft of the first drive motor.

3. The three-degree-of-freedom joint structure according to claim 2, characterized in that, The first gear is connected to the output shaft of the power assist motor via a damping assembly, the damping assembly comprising: A first connecting plate is fixedly connected to the output shaft of the power assist motor; The second connecting plate is fixedly connected to the first connecting plate; A damping shaft, one end of which is inserted into the second connecting plate and can rotate synchronously with the second connecting plate, the damping shaft is provided with a locking part, which can restrict the axial movement between the damping shaft and the second connecting plate; A slip disc is rotatably mounted on the damping shaft, and the first gear is fixedly connected to the slip disc; A spacer sleeve is fitted onto the damping shaft and located between the slip plate and the second connecting plate; A damping nut is threaded to the other end of the damping shaft. A spring washer is provided between the damping nut and the slip plate. When the damping nut is tightened, the spring washer can be pressed against the slip plate.

4. The three-degree-of-freedom joint structure according to claim 3, characterized in that, The damping assembly also includes two shims, which are sleeved on the damping shaft and the slip plate is located between the two shims. The shims can rotate synchronously with the damping shaft.

5. The three-degree-of-freedom joint structure according to claim 1, characterized in that, It also includes a stiffening arm assembly, which comprises: A first connecting seat is fixedly connected to the seat body, and the first connecting seat is opposite to either the first connecting part or the second connecting part; The second connecting seat has one end rotatably connected to the outer circumference of the rotating ring; The swing arm has a bendable middle section. One end of the swing arm is rotatably connected to the first connecting seat, and the other end of the swing arm is rotatably connected to the other end of the second connecting seat. The rotation axes of the rotating parts on the swing arm are parallel to each other.

6. The three-degree-of-freedom joint structure according to claim 5, characterized in that, Also includes: A first spring fixing seat is fixedly mounted on the seat body, and a plurality of first spring fixing holes are provided on the first spring fixing seat; The second spring fixing seat is fixedly disposed on the outer circumference of the rotating ring. The second spring fixing seat is provided with a plurality of second spring fixing holes, the number of which is less than the number of first spring fixing holes.

7. A robotic dinosaur neck skeleton, comprising a three-degree-of-freedom joint structure as described in any one of claims 1 to 6, characterized in that, It also includes a head mounting bracket, which is fixedly connected to the other end of the movable bracket. A third servo motor is symmetrically arranged on both sides of the head mounting bracket. The auxiliary frame assembly includes a connecting frame and a support frame. The connecting frame has a sleeve hole, and the second bushing is fixedly fitted into the sleeve hole. A first bearing is provided on the outer periphery of the connecting frame, and the rotating ring is fitted onto the first bearing. A connecting ring is provided at one end of the support frame, and the connecting ring is fixedly connected to the connecting frame. A support ring is provided in the middle of the support frame, and the main shaft passes through the support ring. One end of the support ring is connected to the connecting ring through several connecting ribs. The other end of the support ring has two outwardly extending connecting arms, which are rotatably connected to the cross shaft. The diameter of the support ring is larger than the diameter of the connecting ring.

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