Modular robotic arm for teaching and testing

Abstract

The application relates to the technical field of teaching mechanical arms, in particular to a modular mechanical arm for teaching and testing, which comprises a base, a large arm, a small arm and a connecting rod driving group, the small arm, the large arm and the base are sequentially assembled through joint rotation, the connecting rod driving group is used for driving the working angle of the large arm and the small arm, and the connecting rod driving group and the small arm are assembled through joint rotation. The coupling shaft quick mounting, the shell quick dismounting lock piece and the coaxial forward and reverse rotation mechanism are designed, joint quick dismounting and shell automatic unfolding are realized, the transparent material makes the whole transmission process visible, a complete teaching closed loop from overall assembly to component observation is constructed, and the teaching efficiency and depth are improved.

Description

Technical Field

[0001] This invention relates to the technical field of teaching robotic arms, specifically a modular robotic arm for teaching and testing. Background Technology

[0002] Currently, the robotic arms widely used in teaching practice in universities are mainly divided into two categories: one is commercial industrial or educational products such as UR5 and Dobot, which adopt an integrated closed design and have a high degree of integration between mechanical structure and electronic control system; the other is some open source robotic arms, which provide model files, but the joints are mostly directly fastened with bolts, making the disassembly and assembly process cumbersome.

[0003] The above structure has significant drawbacks: First, the closed design prevents students from accessing the various structures. Beginners should understand the structural composition of the robotic arm, but it is difficult to intuitively understand the operating mechanism between different functional arms, which deviates from the original intention of practical teaching. Second, the traditional connection method relies on professional tools and precise alignment. Disassembly and reassembly are time-consuming and lengthy, and repeated tightening can easily lead to thread wear and reduced connection reliability. More importantly, this "black box" and "fixed" characteristic seriously hinders students' practice in mechanical configuration reassembly and in-depth debugging, limiting their ability to understand the mechanical body of the robot from various structural aspects.

[0004] Therefore, existing teaching robotic arms generally suffer from the pain points of being difficult to disassemble and assemble and difficult to integrate with teaching, and there is an urgent need for an innovative modular joint interface solution. Summary of the Invention

[0005] This invention provides a modular robotic arm for teaching and testing. By designing a quick-release coupling shaft, a quick-release housing locking mechanism, and a coaxial forward and reverse mechanism, it enables rapid joint assembly and disassembly and automatic housing unfolding. Combined with transparent materials, the internal transmission process is fully visible, constructing a complete teaching loop from overall assembly to component observation, which greatly improves teaching efficiency and depth.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A modular robotic arm for teaching and testing includes: a base, a large arm, a small arm, and a linkage drive assembly. The small arm, large arm, and base are sequentially assembled via joint rotation. The linkage drive assembly is used to drive the working angles of the large arm and small arm, and is assembled with the small arm via joint rotation. It also includes a coupling shaft structure for quick assembly and disassembly between joints. The coupling shaft structure includes a bearing shaft that can be inserted into a joint hole. A positioning structure and a locking structure are respectively installed at both ends of the bearing shaft. The locking structure can be axially displaced along the bearing shaft and abuts against the outer wall of the joint hole. Both the positioning structure and the locking structure can form a rotational friction relationship with the outer wall of the joint hole.

[0008] Optionally, the locking structure includes a second deep groove ball bearing, the inner ring of which is fixedly connected to the outer wall of the bearing shaft, the outer ring of which is fixedly fitted with a bushing that can be sleeved on the outside of the bearing shaft, the inner ring of which is fixedly fitted with a first screw, the end of the bearing shaft away from the positioning structure having a first threaded groove, the first threaded groove and the first screw forming a threaded assembly, the bushing having a through cavity surrounding the outside of the first screw, and the end of the first screw away from the first threaded groove having an internal hexagonal hole.

[0009] Optionally, the positioning structure includes a first deep groove ball bearing, the inner ring of which is fixedly connected to the outer wall of the bearing shaft, and a rubber friction plate is fixedly installed on the outer ring of the first deep groove ball bearing. The rubber friction plate is sleeved on the bearing shaft, and when the assembly is completed, the rubber friction plate abuts against the outer wall at the joint hole.

[0010] Optionally, the forearm is composed of a body shell and a side cover. The forearm is designed with a locking device that tightly locks the body shell and the side cover. The body shell and the side cover rotate along the same axis. The body shell and the side cover are in a contact-fitting fit, and the contact surfaces of the body shell and the side cover are parallel to each other.

[0011] Optionally, the lock includes a latch fixedly mounted on the contact surface of the housing. The latch has a ramp and a flat ramp. The contact surface of the side cover has a lock cavity. The inner wall of the lock cavity is slidably fitted with the flat ramp. A third rotating shaft is fixedly mounted on the inner wall of the lock cavity. A limiting plate is rotatably mounted on the third rotating shaft. The free end of the limiting plate is designed with a ramp. The limiting plate and the third rotating shaft are limited by a torsion spring structure. When the torsion spring structure is in a relaxed state, the bottom of the bearing shaft is at the same slope as the ramp. When the latch contacts the ramp design, the third rotating shaft can be deflected upward, and the ramp of the latch moves to below the limiting plate. At this time, the bottom of the limiting plate is tightly fitted with the ramp. A limiting rod is threaded onto the top of the side cover and extends into the lock cavity. The bottom of the limiting rod is used to prevent the limiting plate from flipping upward.

[0012] Optionally, the top of the side cover is provided with a second threaded groove that extends into the lock cavity. A second screw is threaded into the second threaded groove. A movable column is rotatably mounted at the insertion end of the second screw. A rubber layer is installed at the bottom of the movable column. The bottom of the rubber layer is designed with a slope.

[0013] Optionally, the forearm also includes lugs, and lugs are integrally formed on both the body shell and the side cover. Both lugs have coaxial holes. A first rotating shaft is fixedly connected to the coaxial hole on the body shell, and a second rotating shaft is slidably assembled with a spline in the coaxial hole on the side cover. A retainer is fixedly installed on the top of the upper arm, and a third bevel gear is rotatably installed on the retainer. The outer walls of the first and second rotating shafts are respectively fixedly connected to the first and second bevel gears. The second and first bevel gears are rotatably mounted on the retainer. The first and second bevel gears are located on both sides of the third bevel gear, and the first bevel gear and the spline pin are meshed with the third bevel gear. An assembly shaft is fixedly installed on the second rotating shaft, and an assembly cavity is opened on the first rotating shaft. The assembly shaft and the assembly cavity are rotatably assembled together.

[0014] Optionally, the inner wall of the coaxial hole on the side cover is also designed with a spline groove, and a mounting spline pin is fixedly installed on the outer wall of the second rotating shaft, wherein the spline pin and the spline groove are slidably assembled.

[0015] Optionally, the base, upper arm, and lower arm are made of polycarbonate material and are transparent.

[0016] This invention provides a modular robotic arm for teaching and testing, which has the following advantages compared to existing technologies:

[0017] I. The cooperation between the bearing shaft and the positioning / locking structure achieves a rapid assembly and disassembly effect that is both securely locked and allows for low-interference rotation between joints. The precise cooperation between the bearing shaft, positioning structure, and locking structure together realizes a joint connection scheme for teaching robotic arms. During assembly, students only need to insert the bearing shaft into the aligned joint hole and then tighten the first screw to drive the locking structure to move axially. Together with the positioning structure on the other side, it firmly clamps the joint connector from both sides. The rubber friction plate and bushing are decoupled from the bearing shaft body through deep groove ball bearings. This means that when the joint needs to rotate around the bearing shaft, the two tightly clamped connectors can rotate freely relative to the stationary bearing shaft, greatly reducing rotational friction and resistance torque, and avoiding wear, loosening, and motion interference caused by the relative movement of the threaded pairs in traditional bolted connections. This design separates the two functional domains of "fastening" and "rotation," allowing students to complete the rigid connection and functional release of a joint in tens of seconds with just an Allen wrench. The disassembly process is equally simple, greatly improving the efficiency and operational safety of assembly and disassembly in teaching practice.

[0018] II. The coordination of the body shell, side cover, and locking mechanism enables rapid and reliable locking and one-button safe unlocking of the teaching robotic arm shell. The body shell, side cover, and locking system consisting of a locking tongue, locking cavity, limiting plate, torsion spring, and limiting rod together construct a quick-release shell solution that combines high structural strength with convenient operation. In the closed state, the locking tongue is inserted into the locking cavity, and the limiting plate automatically engages with the slope of the locking tongue under the action of the torsion spring, forming a preliminary lock. Subsequently, tightening the second screw, which serves as the limiting rod, will firmly abut the limiting plate against the movable column and rubber layer at its bottom, completely restricting the possibility of upward rotation, thereby rigidly connecting the body shell and side cover into a whole, which is sufficient to withstand the load during the teaching process.

[0019] Third, the cooperation of the first rotating shaft, the second rotating shaft, the bevel gear set, and the cage enables the automatic opposite-facing unfolding of the shell in the separated state, maximizing the visibility of the internal structure. The transmission cooperation between the first rotating shaft, the second rotating shaft, the first bevel gear, the second bevel gear, the third bevel gear, and the detachable cage creates an automated unfolding mechanism for teaching demonstrations. When it is necessary to observe the inside of the forearm, after removing the shell locking parts, the first rotating shaft is driven externally, and the power is transmitted to the third bevel gear through the fixedly connected first bevel gear, which then drives the second bevel gear that meshes with it. Since the first bevel gear and the second bevel gear are located on both sides of the third bevel gear, their rotation directions must be opposite. This reverse motion is precisely transmitted to the body and side cover via the first rotating shaft fixed to the body and the second rotating shaft connected to the side cover via splines. This drives the two to rotate in opposite directions around a common axis, i.e., "opposite rotation". The effect of this coordination is that it allows the two separated shells to rotate semi-automatically and stagger, forming a wide, blind-spot-free observation window. Students can clearly see all the transmission components inside the shell from multiple angles without having to manually turn it or find specific support points, which significantly improves the efficiency and depth of teaching observation.

[0020] Fourth, the integration of transparent polycarbonate materials with the entire internal structure enables full visualization and immersive learning of the robotic arm's operational status. High-strength transparent polycarbonate is used to manufacture the base, upper arm, and forearm, and systematically integrates with all visible internal transmission mechanisms, creating an immersive learning environment. The benefit of this integration is that it breaks the traditional "black box" state of robotic arms, allowing students to observe every internal component in real-time and intuitively while the robotic arm is powered on and performing various tasks. Abstract mechanical principles, such as transmission ratios, kinematic pairs, torque transmission, and speed transformation, thus become concrete and visual. Students can establish a direct visual connection between instructions, mechanism actions, and the final execution result without disassembly, greatly lowering the barrier to understanding and deepening memory. This fully visualized design transforms the robotic arm from a closed device into a dynamic, transparent "mechanical life form," fundamentally changing the teaching model of robotics principles and stimulating students' desire for exploration and innovative thinking. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the external three-dimensional structure of the present invention;

[0022] Figure 2 This is a schematic diagram of the joint assembly between the forearm and the connecting rod drive assembly of the present invention;

[0023] Figure 3 This is a three-dimensional structural diagram of the coupling shaft structure in this invention;

[0024] Figure 4 This is a three-dimensional structural diagram of the forearm and connecting rod drive assembly in this invention;

[0025] Figure 5 This is a three-dimensional structural diagram of the shell and side cover in this invention;

[0026] Figure 6 This is a three-dimensional cross-sectional view of the locking component in this invention;

[0027] Figure 7 This is a three-dimensional structural diagram of the locking element and limiting rod structure in this invention;

[0028] Figure 8 This is a schematic diagram of the structure of an embodiment of the coaxial forward and reverse rotation of the present invention;

[0029] Figure 9 This is an exploded perspective view of the coaxial forward and reverse rotation structure of the present invention.

[0030] In the diagram: 1. Base; 2. Upper arm; 3. Lower arm; 5. Linkage drive assembly; 6. First deep groove ball bearing; 7. Bearing shaft; 8. Second deep groove ball bearing; 9. First screw; 11. Bushing; 12. Rubber friction plate; 13. First rotating shaft; 14. Second rotating shaft; 15. Cage; 16. Third bevel gear; 17. Second bevel gear; 18. First bevel gear; 19. Spline pin; 20. Assembly cavity; 21. Assembly shaft; 31. Body shell; 32. Side cover; 33. Lug; 34. Locking tongue; 35. Locking cavity; 36. Third rotating shaft; 37. Limiting plate; 38. Movable column; 39. Second screw. Detailed Implementation

[0031] 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.

[0032] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0033] Please see Figures 1 to 9 This invention provides a technical solution: a modular robotic arm for teaching and testing, comprising:

[0034] The system comprises a base 1, an upper arm 2, a lower arm 3, and a linkage drive assembly 5. The lower arm 3, upper arm 2, and base 1 are sequentially assembled via joint rotation. The linkage drive assembly 5 is used to drive the working angles of the upper arm 2 and lower arm 3. The linkage drive assembly 5 and the lower arm 3 are assembled via joint rotation. The system also includes a coupling shaft structure for quick assembly and disassembly between joints. The coupling shaft structure includes a bearing shaft 7 that can be inserted into a joint hole. A positioning structure and a locking structure are respectively installed at both ends of the bearing shaft 7. The locking structure can be axially displaced along the bearing shaft 7 and abut against the outer wall of the joint hole. Both the positioning structure and the locking structure can form a rotational friction relationship with the outer wall of the joint hole.

[0035] In existing technologies, due to the closed design of robotic arms and the closed-source design of commercial robotic arms, students find it difficult to intuitively understand the structural design, function, and principles of robotic arms when learning about these types of robotic arms. This makes it difficult to assemble and disassemble each actuator arm of each robotic arm, and it is impossible to learn the design of individual structures in a modular way. However, in this invention, by designing a bearing shaft 7, when there is a joint assembly between structural arms such as the upper arm 2 and the lower arm 3, it is only necessary to align the joint holes of the two arms and insert the bearing shaft 7 into the two joint holes. At the same time, the positioning structure and locking structure at both ends of the bearing shaft 7 will move closer to each other, thereby abutting against the outer walls of the two joint holes. The abutting relationship is rotational abutting, thereby reducing interference with the movement of the structural arm and limiting the displacement of the two joints. When unlocking and disassembly are required, two students can easily complete the disassembly by cooperating with each other. One student holds or hugs the structural arm, while the other student only needs to move the locking structure away from the positioning structure and further disengage from the bearing shaft 7, so that the bearing shaft 7 is in a free insertion state. At this time, the bearing shaft 7 can be pulled out to separate the assembly relationship of the two joints.

[0036] In a preferred embodiment, the locking structure includes a second deep groove ball bearing 8. The inner ring of the second deep groove ball bearing 8 is fixedly connected to the outer wall of the bearing shaft 7. A bushing 11, which can be sleeved on the outside of the bearing shaft 7, is fixedly installed on the outer ring of the second deep groove ball bearing 8. A first screw 9 is fixedly installed on the inner ring of the second deep groove ball bearing 8. A first threaded groove is formed at the end of the bearing shaft 7 away from the positioning structure. A threaded assembly can be formed between the first threaded groove and the first screw 9. A through cavity is formed on the bushing 11, which surrounds the outside of the first screw 9. An internal hexagonal hole is formed at the end of the first screw 9 away from the first threaded groove. Please refer to [reference needed]. Figures 2 to 4 In this embodiment, when the bearing shaft 7 is inserted into the joint hole, the first screw 9 is connected to the first threaded groove, and the rotation of the first screw 9 is driven by the internal hexagonal hole at its end, so that the first screw 9 and the second deep groove ball bearing 8 gradually approach the outer wall of the joint hole, so that the bushing 11 abuts against the outer wall of the joint hole. Due to the rotational connection between the second deep groove ball bearing 8 and the first screw 9, the bushing 11 can rotate synchronously with the outer wall of the joint hole, thereby achieving locking and non-interference.

[0037] Based on the locking structure embodiment, preferably, the positioning structure includes a first deep groove ball bearing 6, the inner ring of the first deep groove ball bearing 6 is fixedly connected to the outer wall of the bearing shaft 7, and a rubber friction plate 12 is fixedly installed on the outer ring of the first deep groove ball bearing 6. The rubber friction plate 12 is sleeved on the bearing shaft 7. When the assembly is completed, the rubber friction plate 12 abuts against the outer wall of the joint hole. By designing the rubber friction plate 12, hard contact between the rubber friction plate 12 and the outer wall of the joint hole can be avoided. Secondly, the flexibility of the rubber friction plate 12 can improve the friction between the two and avoid friction damage.

[0038] Based on the locking structure embodiment, preferably, the forearm 3 is composed of a body shell 31 and a side cover 32. A locking element is designed on the forearm 3 to tightly lock the body shell 31 and the side cover 32. The body shell 31 and the side cover 32 rotate coaxially, and their contact surfaces are parallel to each other. In this embodiment, to facilitate students' observation of the internal structure, the forearm 3 is designed as a separable shell, allowing the body shell 31 and the side cover 32 to be separated. Furthermore, the coaxially rotating body shell 31 and the side cover 32 can rotate in opposite directions. This allows for a staggered distribution, making it easier for students to observe. Of course, this embodiment can be applied to any structure that can be separated in this invention. Specifically, the body shell 31 and the side cover 32 are parallel to each other and can fit together. Then, they are locked in place by a locking device so that they can work and bear load normally. When it is necessary to observe the internal structure, the body shell 31 and the side cover 32 are separated from each other and then rotated in opposite directions to stagger their distribution. This makes it easier for students to observe the internal structure after separation. They can view the entire structure simply by changing their positions, further improving the convenience of teaching.

[0039] Based on the separable housing embodiment, an embodiment of a locking structure is provided. The locking component includes a latch 34 fixedly mounted on the contact surface of the housing 31. The latch 34 has a ramp and a flat ramp. A locking cavity 35 is formed on the contact surface of the side cover 32. The inner wall of the locking cavity 35 is slidably fitted with the flat ramp. A third rotating shaft 36 is fixedly mounted on the inner wall of the locking cavity 35. A limiting plate 37 is rotatably mounted on the third rotating shaft 36. The free end of the limiting plate 37 is designed with a ramp. The limiting plate 37 and the third rotating shaft 36 are limited by a torsion spring structure. When the torsion spring structure is in a relaxed state, the bottom of the bearing shaft 7 is at the same slope as the ramp. When the latch 34 contacts the ramp design, the third rotating shaft 36 can be deflected upward, and the ramp of the latch 34 moves to below the limiting plate 37. At this time, the bottom of the limiting plate 37 is tightly fitted with the ramp. A limiting rod is threaded onto the top of the side cover 32 and extends into the locking cavity 35. The bottom of the limiting rod is used to prevent the limiting plate 37 from flipping upward. Please refer to [link to relevant documentation]. Figures 5 to 7 In this embodiment, when the contact surfaces of the body shell 31 and the side cover 32 are in contact, the locking tongue 34 will be inserted into the lock cavity 35. At the same time, the locking tongue 34 will contact the inclined surface of the free end of the limiting plate 37, thereby causing the third rotating shaft 36 to shift upward to allow the locking tongue 34 to pass through. When the locking tongue 34 reaches the preset position, the bottom of the limiting plate 37 and the slope of the locking tongue 34 form an inclined surface cooperation, thereby limiting the exit of the locking tongue 34. However, the limiting ability is insufficient, and under strong force, it will still break through the limitation of the torsion spring and escape. By designing a limiting rod, the limiting rod blocks the outer wall of the limiting plate 37, preventing it from flipping upward, thereby effectively locking the locking tongue 34 and preventing the separation between the body shell 31 and the side cover 32.

[0040] Based on the lock embodiment, the top of the side cover 32 has a second threaded groove extending into the lock cavity 35. A second screw 39 is threaded into the second threaded groove. The insertion end of the second screw 39 is rotatably fitted with a movable post 38. A rubber layer is installed at the bottom of the movable post 38, and the bottom of the rubber layer has a beveled design. Please refer to [link to relevant documentation]. Figure 7 To better adapt, unlock, and lock, the second screw 39 is designed to cooperate with the second threaded groove, and the axis of the second threaded groove is perpendicular to the displacement direction of the locking tongue 34, thereby increasing the resistance and limiting the deflection of the limiting plate 37. The cooperation between the movable column 38 and the rubber layer can provide a certain amount of mobility for the limiting plate 37, avoiding damage to the body shell 31 and side cover 32, or damage to the lock components caused by hard contact.

[0041] The ingenuity of this lock and unlock mechanism lies in its "over-center" locking principle and user-friendly unlocking design. When it needs to be opened, simply loosen the second screw 39 a few turns in the opposite direction to release sufficient swing space for the limiting plate 37. At this time, a separation force is applied, and the ramp of the locking tongue 34 can overcome the torsion spring force and push open the limiting plate, achieving a non-destructive separation of the housing. The entire process does not require violent pulling, avoiding damage to parts. Its intuitive "loosen-push" operation logic ensures that even inexperienced students can safely and accurately complete the opening and closing of the housing, greatly encouraging students' exploration of the internal workings of the machine.

[0042] Based on the separable housing embodiment, a coaxial forward and reverse rotation embodiment is provided. The forearm 3 also includes lugs 33. Lugs 33 are integrally formed on both the body shell 31 and the side cover 32. Both lugs 33 have coaxial holes. A first rotating shaft 13 is fixedly connected to the coaxial hole on the body shell 31. A second rotating shaft 14 is slidably fitted into the coaxial hole on the side cover 32. A retainer 15 is detachably fixedly installed on the top of the upper arm 2. A third bevel gear 16 is rotatably mounted on the retainer 15. The first rotating shaft 13 and the second rotating shaft 14 are... The outer wall is fixedly connected to a first bevel gear 18 and a second bevel gear 17, both of which are rotatably mounted on a retainer 15. The first bevel gear 18 and the second bevel gear 17 are located on either side of a third bevel gear 16, and both the first bevel gear 18 and the spline pin 19 are meshed with the third bevel gear 16. An assembly shaft 21 is fixedly mounted on the second rotating shaft 14, and an assembly cavity 20 is formed on the first rotating shaft 13. The assembly shaft 21 and the assembly cavity 20 are rotatably fitted together. Please refer to [link / reference]. Figure 8 and Figure 9Because a retainer 15 is fixedly mounted on the top of the boom 2, and a second bevel gear 17 and a first bevel gear 18 are rotatably mounted on the retainer 15, the second bevel gear 17 is splined to the second shaft 14, the first shaft 13 is fixedly connected to the first bevel gear 18, and the second bevel gear 17 and the first bevel gear 18 are connected by a third bevel gear 16. When the first shaft 13 rotates, it drives the second bevel gear 17 and the second shaft 14 to rotate through a coaxial structure. The rotation direction is opposite to that of the first rotating shaft 13, causing the body shell 31 and side cover 32 to rotate in opposite directions, staggered and opening in a scissor-like pattern, making it easy for students to observe. The rotation of the first rotating shaft 13 is driven by an external structure. It should be noted that the forearm 3 is not connected to the upper arm 2 via the first rotating shaft 13 and the second rotating shaft 14, and the retainer 15 is detachably mounted on the upper arm 2. During teaching, when it is not necessary to separate the body shell 31 and side cover 32, the retainer 15 is released from its fixed position on the upper arm 2. Figures 5 to 7 It can be seen that the bottom of the forearm 3 is hollow, which allows for easy assembly and disassembly of the cage 15 and the upper arm 2.

[0043] The bevel gear in this implementation can also be a straight-helical gear.

[0044] Based on the coaxial forward and reverse rotation embodiment, further, a spline groove is designed on the inner wall of the coaxial hole on the side cover 32, and a mounting spline pin 19 is fixedly installed on the outer wall of the second rotating shaft 14. The spline pin 19 and the spline groove are slidably assembled. Please refer to [link to relevant documentation]. Figure 9 When the side cover 32 is away from the body shell 31, the side cover 32 is designed with spline grooves and spline pins 19, which allows the side cover 32 to slide on the spline pins 19 and the second rotating shaft 14. However, the rotation of the second rotating shaft 14 can still be transmitted to the side cover 32 through the spline pins 19, so that the side cover 32 can rotate relative to the body shell 31.

[0045] The spline connection and coaxial assembly structure enable reliable transmission and motion decoupling of power in an axially displaceable state. The sliding assembly of the spline pin 19 on the second shaft 14 with the spline groove in the coaxial hole of the side cover, and the sleeve rotational assembly with the assembly cavity 20 and assembly shaft 21 of the first shaft 13, together constitute a precise power transmission and motion freedom management system. The spline fit ensures that regardless of the axial position of the side cover 32 relative to the second shaft 14, whether it is in a closed, tightly fitted state or an open, separated state, the rotational power of the second shaft 14 can be transmitted to the side cover 32 without loss and synchronously, driving its rotation. Meanwhile, the sleeved rotational engagement between the assembly shaft 21 and the assembly cavity 20 ensures that although the first rotating shaft 13 and the second rotating shaft 14 are collinear, their rotations are independent and do not interfere with each other. The synergistic effect of these two sets of engagements perfectly solves the contradictory requirements of the shell in the two states of "closed load-bearing" and "separated display": when closed, all components are tightly connected, transmitting power and bearing load; when separated, the side cover 32 can slide open freely and automatically enter the driven opposite unfolding state. This design deeply integrates the functionality and reliability of the structure with the flexibility of its teaching display, providing students with an excellent physical teaching tool for understanding complex kinematic and dynamic connections.

[0046] In summary, in the above embodiments, the base 1, upper arm 2, and lower arm 3 are made of polycarbonate material and are transparent. Polycarbonate has high strength and, under the same conditions, its weight is lower, thereby reducing the burden on students during disassembly and avoiding safety accidents. At the same time, the transparent design allows students to directly observe the real-time motion of internal transmission components such as gears, timing belts, connecting rods, or worm gears, which has educational value. It visualizes abstract concepts such as "transmission ratio" and "motion conversion," helping students intuitively understand mechanical principles.

[0047] This invention systematically solves the core pain points of existing teaching robotic arms—such as strong enclosure, difficult assembly and disassembly, and unintuitive display—through a series of innovative structural combinations. The coupling shaft quick-release structure achieves functional separation of "fastening" and "rotation" between joints, allowing students to safely and quickly assemble and disassemble the entire arm like building blocks. The quick-release locking mechanism of the shell provides a one-button opening and closing experience, balancing convenience during teaching with structural reliability during operation. The coaxial forward and reverse gear transmission mechanism drives the separated shell to automatically unfold in opposite directions, maximizing the exposure of the internal space and achieving optimal observation results. The spline and coaxial assembly ensure reliable power transmission under complex motion conditions, serving as a precise link to achieve the above functions. Finally, the application of fully transparent polycarbonate transforms the entire robotic arm into a dynamic and visual teaching platform, making abstract mechanical principles readily apparent. The synergistic effect of these five effects constructs a complete teaching loop from macroscopic configuration to microscopic mechanism, from hands-on practice to principle observation, greatly improving the efficiency, depth, and interest of engineering education.

[0048] The standard parts used in this embodiment can be purchased directly from the market, and the non-standard structural parts described in the specification and drawings can also be processed without any doubt based on existing technical common sense. At the same time, the connection methods of each component adopt mature conventional methods in the existing technology, and the machinery, parts and equipment all adopt conventional models in the existing technology, so they will not be described in detail here.

[0049] If this invention discloses or relates to mutually fixedly connected components or structural parts, then, unless otherwise stated, a fixed connection can be understood as: a detachable fixed connection (e.g., using bolts or screws), or a non-detachable fixed connection (e.g., riveting, welding). Of course, mutually fixed connections can also be replaced by an integral structure (e.g., manufactured in one piece using a casting process) (except where it is obviously impossible to use an integral molding process).

[0050] Furthermore, unless otherwise stated, the terms used to indicate positional relationships or shapes in any of the technical solutions disclosed in this invention include states or shapes that are similar to, close to, or approximate with those states or shapes. Any component provided by this invention can be assembled from multiple individual components or can be a single component manufactured using a one-piece molding process. Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A modular robotic arm for teaching and testing, characterized in that: include: Base (1); Upper arm (2); Forearm (3); Linkage drive assembly (5); The forearm (3), upper arm (2) and base (1) are assembled sequentially by joint rotation; The linkage drive assembly (5) is used to drive the working angle of the upper arm (2) and the lower arm (3). The linkage drive assembly (5) and the lower arm (3) are connected by joint rotation. It also includes a coupling shaft structure for quick assembly and disassembly between joints; The coupling shaft structure includes a bearing shaft (7) that can be inserted into the joint hole. A positioning structure and a locking structure are respectively installed at both ends of the bearing shaft (7). The locking structure can be axially displaced along the bearing shaft (7) and abut against the outer wall of the joint hole. Both the positioning structure and the locking structure can form a rotational friction relationship with the outer wall of the joint hole. The locking structure includes a second deep groove ball bearing (8), the inner ring of the second deep groove ball bearing (8) is fixedly connected to the outer wall of the bearing shaft (7), the outer ring of the second deep groove ball bearing (8) is fixedly installed with a bushing (11) that can be sleeved on the outside of the bearing shaft (7), the inner ring of the second deep groove ball bearing (8) is fixedly installed with a first screw (9), the end of the bearing shaft (7) away from the positioning structure is provided with a first threaded groove, the first threaded groove and the first screw (9) can form a threaded assembly, the bushing (11) is provided with a through cavity, the through cavity surrounds the outside of the first screw (9), the end of the first screw (9) away from the first threaded groove is provided with an internal hexagonal hole; The positioning structure includes a first deep groove ball bearing (6), the inner ring of which is fixedly connected to the outer wall of the bearing shaft (7), and a rubber friction plate (12) is fixedly installed on the outer ring of the first deep groove ball bearing (6). The rubber friction plate (12) is sleeved on the bearing shaft (7). When the assembly is completed, the rubber friction plate (12) abuts against the outer wall at the joint hole.

2. The modular robotic arm for teaching and testing according to claim 1, characterized in that: The forearm (3) is composed of a body shell (31) and a side cover (32). The forearm (3) is designed with a locking device that tightly locks the body shell (31) and the side cover (32). The body shell (31) and the side cover (32) rotate coaxially. The body shell (31) and the side cover (32) are in a contact fit. The contact surfaces of the body shell (31) and the side cover (32) are parallel to each other.

3. The modular robotic arm for teaching and testing according to claim 2, characterized in that: The lock includes a latch (34) fixedly mounted on the contact surface of the housing (31). The latch (34) has a ramp and a flat ramp. The contact surface of the side cover (32) has a lock cavity (35). The inner wall of the lock cavity (35) is slidably fitted with the flat ramp. A third rotating shaft (36) is fixedly mounted on the inner wall of the lock cavity (35). A limiting plate (37) is rotatably mounted on the third rotating shaft (36). The free end of the limiting plate (37) is designed with a ramp. The limiting plate (37) and the third rotating shaft (36) are connected by a... When the torsion spring structure is in a relaxed state, the bottom of the bearing shaft (7) is at the same slope as the ramp. When the locking tongue (34) comes into contact with the ramp design, the third rotating shaft (36) can be deflected upwards, and the ramp of the locking tongue (34) moves to the bottom of the limiting plate (37). At this time, the bottom of the limiting plate (37) is tightly fitted with the ramp. The top of the side cover (32) is threaded with a limiting rod that penetrates into the lock cavity (35). The bottom of the limiting rod is used to prevent the limiting plate (37) from flipping upwards.

4. The modular robotic arm for teaching and testing according to claim 3, characterized in that: The top of the side cover (32) is provided with a second threaded groove that extends into the lock cavity (35). A second screw (39) is threaded into the second threaded groove. A movable column (38) is rotatably mounted on the insertion end of the second screw (39). A rubber layer is installed at the bottom of the movable column (38), and the bottom of the rubber layer is designed with a slope.

5. The modular robotic arm for teaching and testing according to claim 4, characterized in that: The forearm (3) also includes lugs (33). Lugs (33) are integrally formed on the body shell (31) and the side cover (32). Both lugs (33) have coaxial holes. A first rotating shaft (13) is fixedly connected to the coaxial hole on the body shell (31). A second rotating shaft (14) is slidably assembled in the coaxial hole on the side cover (32). A retainer (15) is fixedly installed on the top of the upper arm (2). A third bevel gear (16) is rotatably installed on the retainer (15). The outer walls of the first rotating shaft (13) and the second rotating shaft (14) are respectively fixedly connected to the first bevel gear. Gear (18) and second bevel gear (17), the second bevel gear (17) and the first bevel gear (18) are rotatably mounted on the cage (15), the first bevel gear (18) and the second bevel gear (17) are respectively located on both sides of the third bevel gear (16), and the first bevel gear (18) and spline pin (19) are meshed with the third bevel gear (16). An assembly shaft (21) is fixedly mounted on the second rotating shaft (14), and an assembly cavity (20) is opened on the first rotating shaft (13). The assembly shaft (21) and the assembly cavity (20) are sleeved and rotated together.

6. The modular robotic arm for teaching and testing according to claim 5, characterized in that: The inner wall of the coaxial hole on the side cover (32) is also designed with a spline groove, and a spline pin (19) is fixedly installed on the outer wall of the second rotating shaft (14), and the spline pin (19) and the spline groove are slidably assembled.

7. The modular robotic arm for teaching and testing according to claim 1, characterized in that: The base (1), upper arm (2) and lower arm (3) are made of polycarbonate material and are transparent.

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