Robotic arm joint irregular sealing device and cooking robot

Abstract

This application discloses a non-standard sealing device for a robotic arm joint and a cooking robot, relating to the field of robotics technology. The device includes a sealing ring comprising: a sealing body with a static sealing end face facing a first mechanical component and a dynamic sealing end face facing a second mechanical component; the static sealing end face and the end face of the first mechanical component form a static seal; the dynamic sealing end face and the end face of the second mechanical component form a dynamic seal; after the sealing ring is installed, the outer diameter of the sealing body is not less than the outer diameter of the first mechanical component; and a sealing lip extending from the side of the sealing body away from the static sealing end face and abutting against the flange end face of the second mechanical component, the sealing lip maintaining dynamic contact with the flange end face of the second mechanical component during rotation. This solves the problems in related technologies where robotic arms in cooking scenarios easily accumulate oil stains in the joint gaps, are difficult to clean, and cause food safety issues due to wear debris falling off.

Description

Technical Field

[0001] This application relates to the field of robotics technology, and more specifically, to a robotic arm joint irregular sealing device and a cooking robot. Background Technology

[0002] In complex environments such as automated cooking, characterized by heavy oil stains and high humidity, cooking robots are widely used due to their efficiency, hygiene, and standardization. As the core actuator of a cooking robot, the sealing performance of its joints directly affects the reliability and lifespan of the entire machine. However, in heavily oiled environments, robotic arms accumulate significant amounts of grease over time. During manual cleaning, the gaps at the joints easily trap dirt and grime. After a period of operation, the grease solidifies, increasing the robot's resistance to movement, and the grease, often black, flows out through these gaps, affecting the robot's appearance and overall cleanliness. Furthermore, the kitchen environment demands extremely high standards of food hygiene and safety. Poorly sealed robotic arm joints can lead to metal shavings from joint wear or lubricating grease from the joints falling into the food, posing a significant safety risk.

[0003] Currently, there are three main methods for sealing the joints of robotic arms: First, relying on the waterproof seal of the joint's rotational position, and applying sealant to the inner and outer flanges of the robotic arm structural components and the joint to achieve a waterproof effect. Second, the joint itself does not require waterproofing; instead, a skeleton oil seal or O-ring is used during robotic arm assembly to seal the spaces between the structural components. Third, the joint itself does not require waterproofing; instead, a polymer ring (such as nylon) combined with a soft rubber ring is used during robotic arm assembly to seal the spaces between the structural components. In this solution, the soft rubber acts as a spring, pushing the polymer ring to one side to contact the moving parts of the robotic arm, achieving a dynamic seal.

[0004] Using either of these methods, oil stains can easily seep into and accumulate inside the joint gaps after the robotic arm has been running for a period of time. Not only are they difficult to clean, but once they solidify, they will significantly increase the resistance to joint movement, affecting the robotic arm's movement accuracy and response speed.

[0005] If the third sealing method is adopted, the sealing device includes a hard ring formed by a polymer ring (such as nylon) and a soft ring formed by a soft rubber ring. The seal is formed by the compression of the hard ring and the soft ring. After long-term use, if the sealing device needs to be maintained or replaced due to wear or aging, the hard ring has poor elasticity, so the entire robotic arm must be disassembled for replacement, which is extremely inconvenient for maintenance and replacement.

[0006] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0007] The main purpose of this application is to provide a non-standard sealing device for the joints of a robotic arm and a cooking robot, so as to solve the problems of easy oil accumulation, inconvenient cleaning, and inconvenient maintenance of robotic arms in medium to heavy oily environments.

[0008] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description or may be learned by practice of this application.

[0009] According to a first aspect of this application, a robotic arm joint irregular sealing device is provided. The robotic arm joint includes a first mechanical structural member and a second mechanical structural member disposed opposite to each other. The second mechanical structural member is rotatable relative to the first mechanical structural member about an axis. The sealing device includes a sealing ring made of an elastic material. The sealing ring is deformable under external tensile force and has at least a partial recovery deformation capability after the tensile force is removed. The sealing ring is embedded in an annular gap between the first mechanical structural member and the second mechanical structural member.

[0010] The sealing ring includes:

[0011] The sealing body has a static sealing end face on the side facing the first mechanical structural component and a dynamic sealing end face on the side facing the second mechanical structural component. The static sealing end face is tightly fitted with the flange end face of the first mechanical structural component to form a static seal, and the first mechanical structural component is fixed relative to the sealing ring. There is a gap between the dynamic sealing end face and the flange end face of the second mechanical structural component to form a dynamic seal, and the second mechanical structural component rotates relative to the sealing ring. After the sealing ring is installed in place, the outer circumferential diameter of the sealing body is not less than the outer circumferential diameter of the first mechanical structural component.

[0012] The sealing lip extends from the side of the sealing body away from the static sealing end face toward the flange end face of the second mechanical structure and abuts against the flange end face of the second mechanical structure. The sealing lip can maintain dynamic contact with the flange end face of the second mechanical structure at all times when the second mechanical structure rotates, so as to form a dynamic seal.

[0013] In one exemplary embodiment of this application, the sealing body has an annular groove on the side facing the second mechanical structure, the annular groove surrounds the outer periphery of the sealing lip, and at least a portion of the inner wall of the sealing lip is in contact with the outer wall of the second mechanical structure near the first mechanical structure.

[0014] At least one opening is provided on the circumferential outer wall of the sealing body, and the opening is connected to the annular groove.

[0015] In one exemplary embodiment of this application, the length of the sealing lip is greater than the distance from the second mechanical structural member to the end of the sealing lip away from the second mechanical structural member, such that the sealing lip is compressed in the installed state and maintains a pre-tight fitting force on the flange end face of the second mechanical structural member, and the end of the sealing lip that fits against the second mechanical structural member is turned outward in a direction away from the axis of rotation.

[0016] In one exemplary embodiment of this application, at least a portion of the outer periphery of the sealing body is configured as a positioning sealing ring, the positioning sealing ring surrounding and fitting the circumferential outer wall of the first mechanical structure;

[0017] The positioning sealing ring is made of elastic material. In its free state, the inner diameter of the positioning sealing ring is smaller than the outer diameter of the first mechanical structure. After installation, it applies a continuous radial clamping force to the circumferential outer wall of the first mechanical structure through elastic deformation, thereby restricting the axial movement and circumferential rotation of the sealing ring relative to the first mechanical structure.

[0018] In one exemplary embodiment of this application, the connection between the positioning sealing ring and the sealing body is provided with an annular transition groove, which is located on the outer periphery of the sealing body near the static sealing end face.

[0019] In one exemplary embodiment of this application, the sealing ring is a one-piece molded structure made of a single elastic material.

[0020] In one exemplary embodiment of this application, the elastomeric material constituting the sealing ring has a hardness of not less than 50 Shore A and a maximum stretchable length of not less than 125% of the initial length.

[0021] In one exemplary embodiment of this application, after the elastic material constituting the sealing ring is stretched to the maximum limit, the external force is removed and the material is allowed to rest and recover its deformation. The change rate of the length of the sealing ring after recovery of deformation compared to the initial length does not exceed 0.5%.

[0022] According to a second aspect of this application, a cooking robot is provided, comprising the robotic arm joint irregular sealing device and the robotic arm as described in any one of the above claims.

[0023] In one exemplary embodiment of this application, the robotic arm joint irregular sealing device is applicable to at least the first joint between the base and the upper arm, the second joint between the upper arm and the lower arm, and the third joint between the lower arm and the end effector in the robotic arm.

[0024] The exemplary embodiments of this application may have some or all of the following beneficial effects:

[0025] In the robotic arm joint irregular sealing device provided in the example embodiment of this application, by embedding a sealing ring made of elastic material in the annular gap between the first and second mechanical structural components, not only is a reliable seal achieved through dynamic and static integration, but cleanliness and maintenance convenience are also effectively improved. Specifically, after installation, the outer diameter of the sealing ring body is not less than the outer diameter of the first mechanical structural component, so that the outer edge of the sealing ring can cover or be flush with the outer contour of the first mechanical structural component. This effectively eliminates the recessed gaps formed by component misalignment or steps in traditional structures, thereby reducing the space for oil, moisture and other pollutants to accumulate on the outside of the joint, making it difficult for dirt to seep into the gaps, and making the surface smoother and easier to wipe and clean daily. It is particularly suitable for applications with high oil and high hygiene requirements, such as cooking robots. Furthermore, thanks to the sealing ring being made of a material with excellent elasticity and shape recovery, its installation and disassembly are extremely simple: during installation, only a tensile force is applied to the sealing ring to expand it, fitting it into the mating area of ​​the first and second mechanical structural components. Once aligned with the annular gap, it is released, and the sealing ring automatically contracts and tightly embeds itself into the gap due to its own elasticity. Similarly, during disassembly, only a pulling force is applied from the outside to stretch and deform it, allowing it to be easily removed from the gap without disassembling the robotic arm or using special tools. This quick-installation and disassembly structure greatly reduces maintenance costs and downtime, improving equipment availability and work efficiency. Simultaneously, the sealing ring forms a stable static seal with the first mechanical structural component through its static sealing end face, and maintains dynamic contact with the rotating second mechanical structural component through its dynamic sealing end face equipped with an elastic sealing lip. This ensures good sealing performance even during continuous joint movement, effectively preventing external contaminants from intruding and internal lubricating medium leakage. Thus, it achieves high reliability, easy cleaning, and convenient replacement in the compact and space-constrained robotic arm joint.

[0026] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0027] The accompanying drawings, which form part of this application, are used to provide a further understanding of the application and to make other features, objects, and advantages of the application more apparent. The illustrative embodiments and descriptions of this application are used to explain the application and do not constitute an undue limitation of the application. In the drawings:

[0028] Figure 1 A partial structural schematic diagram of the connection between the first mechanical structural component and the second mechanical structural component in an embodiment of this application is shown;

[0029] Figure 2 It shows Figure 1 A magnified view of part A in the middle;

[0030] Figure 3 A schematic diagram of the sealing ring structure in an embodiment of this application is shown;

[0031] Figure 4 A schematic diagram of the robotic arm in an embodiment of this application is shown.

[0032] Among them, 1. First mechanical structural component; 2. Second mechanical structural component; 3. Sealing ring; 31. Static sealing end face; 32. Dynamic sealing end face; 33. Sealing lip; 34. Annular groove; 35. Annular transition groove; 36. Positioning sealing ring; 4. Base; 5. Main arm; 6. Forearm; 7. End effector. Detailed Implementation

[0033] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this application will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed descriptions will be omitted. Furthermore, the drawings are merely illustrative of this application and are not necessarily drawn to scale.

[0034] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of an icon to another, these terms are used only for convenience, such as according to the orientation of the examples in the accompanying drawings. It is understood that if the device of the icon is flipped so that it is upside down, the component described as "upper" will become the component described as "lower." When a structure is "upper" of another structure, it may mean that the structure is integrally formed on the other structure, or that the structure is "directly" mounted on the other structure, or that the structure is "indirectly" mounted on the other structure through another structure.

[0035] The terms “a,” “one,” “the,” and “at least one” are used to indicate the existence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.; the terms “first” and “second” are used only as markers and are not a limitation on the number of objects.

[0036] Furthermore, the terms "set up," "equipped with," "connected," and "fixed" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0037] In addition, the term "multiple" should mean two or more.

[0038] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0039] In kitchen settings, where food hygiene and safety requirements are extremely high, inadequate sealing of robotic arm joints can lead to metal shavings from joint wear or lubricating grease leaking into food, posing a significant safety risk. Therefore, this application provides a sealing device for robotic arm joints to improve their sealing performance. Example 1

[0040] Reference Figures 1-3 As shown in the embodiment of this application, a non-circular sealing device for a robotic arm joint is disclosed. The robotic arm joint includes a first mechanical structure 1 and a second mechanical structure 2 disposed opposite to each other, wherein the second mechanical structure 2 is rotatable relative to the first mechanical structure 1 about an axis. For example, the first mechanical structure 1 can be constructed as an upper arm, and the second mechanical structure 2 can be constructed as a lower arm. The two are connected by a drive mechanism (such as a motor and its output shaft), and relative rotation is achieved with the output shaft as the axis of rotation.

[0041] It should be noted that the examples of the first mechanical component 1 and the second mechanical component 2 described above are merely illustrative and are not intended to limit the scope of protection of this invention. In other embodiments, the first mechanical component 1 may also be constructed as a base, in which case the second mechanical component 2 may be constructed as a large arm connected to the base; or, the first mechanical component 1 may be constructed as a forearm, in which case the second mechanical component 2 may be constructed as an end effector connected to the forearm. Regardless of the specific configuration, as long as there is a relative rotational relationship between the two components, the sealing device provided in this application can be applied.

[0042] In one specific embodiment, an annular gap is formed between the docking areas of the first mechanical structural member 1 and the second mechanical structural member 2, and the gap is continuously distributed along the circumference.

[0043] In this embodiment, the sealing device is embedded in the annular gap formed by the first mechanical structural member 1 and the second mechanical structural member 2. The sealing device includes a sealing ring 3 made of elastic material. The sealing ring 3 is generally annular and has the ability to undergo reversible deformation under external tensile force. After the tensile force is removed, it can at least partially restore its original shape, thereby facilitating installation and disassembly.

[0044] Furthermore, the sealing ring 3 includes a sealing body and a sealing lip 33. A static sealing end face 31 is formed on the side of the sealing body facing the first mechanical component 1. The static sealing end face 31 is tightly fitted with the flange end face of the first mechanical component 1, forming a static seal. Since the sealing ring 3 has no relative movement with the first mechanical component 1 after assembly, and the two remain relatively fixed, external contaminants can be effectively prevented from entering the joint from the fixed connection. A dynamic sealing end face 32 is formed on the side of the sealing body facing the second mechanical component 2. A gap exists between the dynamic sealing end face 32 and the flange end face of the second mechanical component 2, forming a dynamic sealing area, allowing the second mechanical component 2 to rotate freely about its axis relative to the sealing ring 3.

[0045] Specifically, after the sealing ring 3 is installed, the outer diameter of its sealing body is not less than the outer diameter of the first mechanical structural component 1, so that the outer edge of the sealing ring 3 is at least flush with the outer contour of the first mechanical structural component 1, or even slightly convex. This design effectively covers the recessed area formed by flange steps or adjacent flanges in traditional structures, thus preventing oil stains and water stains from accumulating in the gaps on the outer surface of the joint. This not only improves the overall appearance of the machine but also greatly facilitates daily cleaning and maintenance.

[0046] The sealing lip 33 extends from the side of the sealing body away from the static sealing end face 31 toward the flange end face of the second mechanical structure 2, and its free end abuts against the flange end face of the second mechanical structure 2. When the second mechanical structure 2 rotates, the sealing lip 33 moves relative to the flange end face of the second mechanical structure 2, and relies on its elasticity to continuously fit together, thereby forming a continuous and self-adaptive dynamic sealing barrier, effectively preventing external oil, steam or cleaning fluid from entering the joint, while preventing internal lubricating grease from leaking out.

[0047] Preferably, the sealing body and the sealing lip 33 are an integral structure.

[0048] It is worth noting that the free end of the sealing lip 33 is smaller than its root dimension, exhibiting a tapered structure. This design effectively reduces the contact area between the sealing lip 33 and the flange end face of the second mechanical structure 2, thereby reducing frictional resistance and improving the smoothness of the robotic arm's operation while ensuring sealing performance. Simultaneously, it reduces wear on the sealing lip 33 and extends the service life of the sealing ring 3.

[0049] Furthermore, the circumferential inner wall of the sealing lip 33 is at least partially in close contact with the outer wall of the second mechanical component 2 on the side closest to the first mechanical component 1. Specifically, this contact area is located at the rotational connection between the second mechanical component 2 and the first mechanical component 1, that is, the sealing lip 33 is in axial contact with its circumferential outer wall. Through this structural design, the seam between the first mechanical component 1 and the second mechanical component 2 can be effectively concealed, making it difficult for metal wear debris generated inside the joint due to relative rotation to escape; at the same time, this sealing structure will not interfere with the relative rotation between the two components, thereby ensuring smooth and reliable movement. In the embodiment of this application, the installation process of the sealing ring 3 is as follows: First, the sealing ring 3 is stretched circumferentially to expand its inner diameter to be sufficient to fit over the mating part of the first mechanical component 1 and the second mechanical component 2; then, it is fitted onto the mating area of ​​the two components and aligned with the annular gap; after being released, the sealing ring 3 automatically embeds itself into the annular gap and forms a pre-tight fit due to its own elastic contraction. During disassembly, simply apply a pulling force from the outside to stretch and deform the sealing ring 3, and it can be easily removed from the gap without disassembling the robotic arm and other internal components, effectively improving maintenance efficiency.

[0050] In summary, the robotic arm joint irregular sealing device provided in this embodiment, while ensuring the reliability of dynamic and static sealing, also has the advantages of preventing dirt accumulation, easy cleaning, and quick installation and disassembly. It is particularly suitable for application scenarios such as automated cooking equipment with high oil stains, high humidity and heat, and strict requirements for hygiene and maintenance efficiency.

[0051] Furthermore, the sealing body has an annular groove 34 on the side facing the second mechanical structure 2, which surrounds the outer periphery of the sealing lip 33. After the sealing ring 3 is installed in place, the annular groove 34, together with the flange end face of the second mechanical structure 2 and adjacent structures, forms an annular cavity, which can be used to temporarily contain contaminants such as oil and water vapor.

[0052] Furthermore, at least one opening is provided on the circumferential outer wall of the sealing body, which communicates with the aforementioned annular groove 34. During actual use, if oil, moisture, or other impurities accumulate in the annular groove 34, they can be naturally drained or cleaned through this opening. Especially when the robotic arm is in a specific posture (such as joint tilting or inversion), the opening can serve as a drainage channel, preventing contaminants from remaining in the groove for extended periods and solidifying or corroding the sealing interface. Simultaneously, during maintenance, cleaning agents or lubricating media can be injected through this opening for easy maintenance of the sealing area. This structural design enhances the cleaning capability and environmental adaptability of the sealing device without adding additional components.

[0053] In this embodiment, the opening is preferably an annular groove that extends continuously along the circumference of the sealing ring 3. The annular groove extends to the outer circumferential surface of the sealing body and communicates with the annular groove 34, thereby forming a continuous drainage channel. In other embodiments, the opening may also be constructed as multiple through holes, which are spaced apart on the circumferential outer wall of the sealing body and are respectively connected to the annular groove 34.

[0054] In this embodiment, the length of the sealing lip 33 is greater than the distance from the end of the second mechanical structure 2 away from the sealing lip 33; that is, the length of the sealing lip 33 is greater than the distance from the second mechanical structure 2 to the connection point between the sealing lip 33 and the sealing body. After the sealing ring 3 is installed, the sealing lip 33 undergoes elastic compression deformation under pressure, thereby continuously applying a pre-tightening force to the flange end face of the second mechanical structure 2, ensuring the reliability of the dynamic seal. Furthermore, the end of the sealing lip 33 that contacts the flange end face of the second mechanical structure 2 is turned outwards in a direction away from the axis of rotation. In practical applications, the outward-turned structure of the sealing lip 33 not only allows it to more gently conform to the rotating end face after pressure installation, effectively adapting to flange processing errors, assembly deviations, or minor axial runout caused by load during operation, thus maintaining the continuity and reliability of the dynamic seal; simultaneously, the outward-turned shape changes the stress distribution in the contact area, increasing the contact area and making the sealing lip 33 less prone to stress concentration and damage, thus helping to extend the service life of the sealing ring 3. Furthermore, with its outward orientation facing the external environment, the annular groove utilizes its structure and surface tension to guide oil, moisture, or cleaning fluid from inside to the outside. More importantly, this flexible structure offers better tolerance for creep and thermal expansion of materials under high temperatures or long-term use, mitigating the risk of seal failure due to deformation accumulation and thus achieving stable and long-lasting sealing performance under complex operating conditions.

[0055] In one specific embodiment, at least a portion of the outer periphery of the sealing body is configured as a positioning sealing ring 36, which surrounds and adheres to the circumferential outer wall of the first mechanical structure 1 in the installed state. The positioning sealing ring 36 is made of an elastic material (such as fluororubber, silicone, or thermoplastic elastomer) that is the same as or compatible with the sealing body, and its inner diameter is smaller than the outer diameter of the first mechanical structure 1 in the free, uninstalled state. When the sealing ring 3 is stretched and fitted into the annular gap between the first mechanical structure 1 and the second mechanical structure 2, the positioning sealing ring 36 elastically expands due to the constraint of the outer wall of the first mechanical structure 1, thereby applying a continuous radial clamping force to the circumferential outer wall of the first mechanical structure 1 under its restoring tendency.

[0056] The radial clamping force, on the one hand, fixes the sealing ring 3 circumferentially to the first mechanical structural component 1, effectively preventing relative rotation of the sealing ring 3 due to vibration or torque transmission during the operation of the robotic arm; on the other hand, it increases the frictional resistance between the sealing ring 3 and the first mechanical structural component 1, significantly suppressing the axial displacement of the sealing ring 3 that may occur under the influence of gravity, assembly tolerances, or thermal expansion and contraction. Therefore, the static sealing end face 31 can always maintain a tight fit with the flange end face of the first mechanical structural component 1, making it less prone to loosening and sealing failure.

[0057] Furthermore, an annular transition groove 35 is provided at the connection between the positioning sealing ring 36 and the sealing body. This annular transition groove 35 is located in the outer peripheral area of ​​the sealing body near the static sealing end face 31. The transition groove extends continuously in the circumferential direction, forming a local structural weakening area. When the sealing ring 3 is installed on the first mechanical structural component 1, it can effectively release the local stress concentration caused by the pressure expansion of the positioning sealing ring 36, ensuring that the sealing ring 3 will not tear or permanently deform at the connection root. At the same time, the presence of the annular transition groove 35 gives the positioning sealing ring 36 a larger flexible deformation space when subjected to radial clamping force, which helps it to fit more evenly against the outer wall of the first mechanical structural component 1 and improve the uniformity of clamping force distribution.

[0058] In a specific embodiment, the sealing ring 3 is integrally formed from a single elastic material through molding or injection molding, eliminating the need for bonding, welding, or multi-part assembly. This integrated structure ensures no interface gaps between the sealing body, sealing lip 33, and positioning sealing ring 36, thus reducing the likelihood of insufficient sealing due to material delamination, adhesive failure, or assembly misalignment. This effectively improves the overall reliability and long-term durability of the sealing device. Simultaneously, the use of a single material simplifies the production process, reduces manufacturing costs, and ensures consistency of each functional component under temperature changes, oil contamination, or dynamic loads.

[0059] In one specific embodiment, the elastomeric material constituting the sealing ring 3 has specific mechanical property requirements: its Shore A hardness is not less than 50 to ensure that it can maintain sufficient structural stiffness and deformation resistance under long-term pressure, avoiding the collapse of the sealing lip 33 or the attenuation of the clamping force of the positioning sealing ring 36 due to excessively soft material; at the same time, the maximum elastic limit of the material is not less than 125% of its initial length, that is, it can withstand at least 25% tensile strain without plastic deformation or fracture when subjected to installation tension. This high elastic elongation ensures that the sealing ring 3 can be fully stretched during assembly to fit into the mechanical structural parts, and quickly returns to the design size after release, achieving reliable fitting and pre-tightening sealing. The above-mentioned synergistic design of hardness and tensile properties enables the sealing ring 3 to have excellent rebound stability, wear resistance and long-term sealing durability while taking into account the convenience of installation, making it particularly suitable for robotic arm joint applications that require frequent disassembly and assembly or are in environments with high oil and high humidity and heat.

[0060] Furthermore, after the elastomeric material constituting the sealing ring 3 undergoes multiple stretching cycles to its maximum elastic limit (i.e., not less than 125% of the initial length) followed by the removal of external force, and then is left to stand at room temperature for 12 hours, the rate of change of its final free length relative to the initial length does not exceed ±0.5%. This performance indicator shows that the residual stress inside the material is extremely low. In practical applications, this means that even after repeated disassembly and assembly or long-term service, the sealing ring 3 can still maintain highly consistent geometric dimensions and preload, avoiding problems such as decreased sealing capacity of the sealing ring 3 and weakened clamping force of the positioning sealing ring 36 due to material "loosening" or "permanent elongation," thereby ensuring the long-term reliability of the dynamic and static sealing interface.

[0061] To verify the beneficial effects of the technical solution of this invention, a comparative experiment was conducted as shown in Table 1 below. All three groups of samples used sealing rings 3 with the same geometric structure (including the sealing body, the everted sealing lip 33, and the positioning sealing ring 36), differing only in material parameters such as material and hardness, as detailed below:

[0062] Material Indentation hardness Actual hardness Design length Length before stretching Length after multiple stretching After multiple stretching cycles, allow to stand for 0.5 hours. Let it stand for 12 hours after multiple stretching. Elasticity limit Internal stress deformation Design deviation Demand outer diameter Optimize outer diameter Final diameter Comparative Example 1 silicone have 70 60 311 315 328 325 322 33.5% 2.2% 3.5% 103 99.48 97.48136646 Comparative Example 2 Natural rubber slight 70 60 311 318 330 321 320 56.3% 0.6% 2.9% 103 100.10 98.103125 Comparative Example 3 High resilience silicone rubber none 70 62 311 315 318 317 316 58.2% 0.3% 1.6% 103 101.37 99.37025316

[0063] Table 1

[0064] As can be seen from the above data, Comparative Example 3 has significant advantages over Comparative Examples 1 and 2: it has the highest elastic limit (58.2%), indicating that the material can withstand a greater degree of tensile deformation without failure, which is beneficial for repeated disassembly and assembly; it has the smallest internal stress deformation (only 0.3%), indicating that the material has low internal residual stress and excellent dimensional stability after repeated use or long-term static storage; the design deviation is only 1.6%, which is much lower than that of Comparative Example 1 (3.5%) and Comparative Example 2 (2.9%), meaning that the actual molding size is closer to the theoretical design value, thereby ensuring higher fitting accuracy between the sealing ring 3 and the mechanical structural parts.

[0065] Therefore, in this application, the sealing ring 3 is preferably made of high-resilience silicone rubber, but this is not a limiting factor.

[0066] Example 2

[0067] Reference Figure 4 As shown in the embodiments of this application, a cooking robot is disclosed. The cooking robot includes a robotic arm and a non-circular sealing device for the robotic arm joints as described in Embodiment 1. This non-circular sealing device can be applied to multiple rotating joints of the robotic arm, including at least: a first joint between the base 4 and the upper arm 5, a second joint between the upper arm 5 and the lower arm 6, and a third joint between the lower arm 6 and the end effector 7. The end effector 7 can be a gripper, but this is not a limitation. In each of the above joints, the sealing device effectively blocks the intrusion of external oil, steam, and cleaning fluid, while preventing leakage of internal lubricating media. It also has advantages such as easy cleaning, quick disassembly and assembly, and long-term dimensional stability, thereby significantly improving the operational reliability and maintenance convenience of the cooking robot in high-oil, high-humidity and high-heat environments.

[0068] Other embodiments of this application will readily conceive of by those skilled in the art upon consideration of the specification and practice of the embodiments thereof. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not claimed in this application. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of this application are indicated by the appended claims.

Claims

1. A special-shaped sealing device for a mechanical arm joint, the mechanical arm joint comprising a first mechanical structural member and a second mechanical structural member arranged oppositely, the second mechanical structural member being capable of rotating relative to the first mechanical structural member about an axis, characterized in that, The sealing device includes a sealing ring made of elastic material, which is capable of deforming under external tensile force and has the ability to at least partially recover its deformation after the tensile force is removed. The sealing ring is embedded in the annular gap between the first mechanical structural component and the second mechanical structural component. The sealing ring includes: The sealing body has a static sealing end face on the side facing the first mechanical component and a dynamic sealing end face on the side facing the second mechanical component. The static sealing end face is tightly fitted with the flange end face of the first mechanical component to form a static seal, and the first mechanical component is fixed relative to the sealing ring. There is a gap between the dynamic sealing end face and the flange end face of the second mechanical component, and the second mechanical component rotates relative to the sealing ring. After the sealing ring is installed in place, the outer circumferential diameter of the sealing body is not less than the outer circumferential diameter of the first mechanical component. The sealing lip extends from the side of the sealing body away from the static sealing end face toward the flange end face of the second mechanical structure and abuts against the flange end face of the second mechanical structure. The sealing lip can always maintain dynamic contact with the flange end face of the second mechanical structure when the second mechanical structure rotates, so as to form a dynamic seal. The sealing body has an annular groove on the side facing the second mechanical structure, and the annular groove surrounds the outer periphery of the sealing lip; At least a portion of the outer periphery of the sealing body is configured as a positioning sealing ring, which surrounds and fits against the circumferential outer wall of the first mechanical structure. The positioning sealing ring is made of elastic material. In its free state, the inner diameter of the positioning sealing ring is smaller than the outer diameter of the first mechanical structure. After installation, it applies a continuous radial clamping force to the circumferential outer wall of the first mechanical structure through elastic deformation, thereby restricting the axial movement and circumferential rotation of the sealing ring relative to the first mechanical structure.

2. The irregular sealing device for robotic arm joints according to claim 1, characterized in that, At least a portion of the inner wall of the sealing lip is in contact with the outer wall of the second mechanical structure near the first mechanical structure; at least one opening is provided on the outer wall of the sealing body, and the opening is connected to the annular groove.

3. The irregular sealing device for robotic arm joints according to claim 1, characterized in that, The length of the sealing lip is greater than the distance from the second mechanical structural component to the end of the sealing lip away from the second mechanical structural component, so that the sealing lip is compressed in the installed state and maintains a pre-tight fit force on the flange end face of the second mechanical structural component, and the end of the sealing lip that fits against the second mechanical structural component is turned outward in a direction away from the axis of rotation.

4. The irregular sealing device for robotic arm joints according to claim 1, characterized in that, The connection between the positioning sealing ring and the sealing body is provided with an annular transition groove, which is located on the outer periphery of the sealing body near the static sealing end face.

5. The robotic arm joint irregular sealing device according to any one of claims 1-4, characterized in that, The sealing ring is a one-piece molded structure made of a single elastic material.

6. The irregular sealing device for robotic arm joints according to claim 5, characterized in that, The elastomeric material constituting the sealing ring has a hardness of not less than 50 Shore A and a maximum stretchable length of not less than 125% of the initial length.

7. The irregular sealing device for robotic arm joints according to claim 6, characterized in that, After the elastic material constituting the sealing ring is stretched to the maximum limit, the external force is removed and the ring is allowed to recover its deformation at rest. The change rate of the length of the sealing ring after recovery of deformation compared to the initial length does not exceed 0.5%.

8. A cooking robot, characterized in that, Includes the robotic arm joint irregular sealing device and robotic arm as described in any one of claims 1-7.

9. The cooking robot according to claim 8, characterized in that, The irregular sealing device for the robotic arm joints is applicable to at least the first joint between the base and the upper arm, the second joint between the upper arm and the lower arm, and the third joint between the lower arm and the end effector in the robotic arm.

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