A linear joint output end sealing structure of a humanoid robot

Abstract

This invention relates to the field of robot joint module structure technology, and particularly to a sealing structure for the output end of a linear joint of a humanoid robot. The structure is located at the output rod and includes a front cover. A section of the front cover has a rod hole that fits clearanceably with the output rod. This section of the rod hole also connects to two sections of rod holes, each with an intermediate sealing layer. An outer sealing layer is located around the periphery of the intermediate sealing layer. The inner end of the intermediate sealing layer faces the inner port of the two sections of rod holes, and the outer end of the intermediate sealing layer faces the outer port of the two sections of rod holes. The outer ports of the two sections of rod holes are closed by an end cover and press against the intermediate sealing layer. An inner sealing layer is located on the output rod opposite the intermediate sealing layer. By forming a stable sealing structure, the lubrication requirements of the output rod are met while preventing lubricant overflow, thus avoiding material waste and external contamination. This also reduces the need for frequent maintenance, making it more convenient to use and extending its effective service life.

Description

Technical Field

[0001] This invention relates to the field of robot joint module structure technology, and in particular to a sealing structure for the output end of a linear joint of a humanoid robot. Background Technology

[0002] Robots are now expanding into fields such as home entertainment, healthcare, and industrial manufacturing. These fields, in particular, place extremely high demands on robots' load-bearing capacity, precision, and reliability. To better meet these needs, linear robot joint modules (hereinafter referred to as linear joints) utilize reverse planetary roller screws. This structure offers higher precision and load-bearing capacity compared to linkage structures, and its mechanical structure also possesses a certain degree of self-locking capability, perfectly suited to the current requirements of humanoid robots. For example, some robots employ 14 linear joints of different specifications to improve performance; others now use 22 linear joints of 5 different specifications, and so on. However, to ensure that the reverse planetary roller screw can correctly perform its structural function—that is, to convert the motor's rotational torque into linear thrust—an anti-rotation structure design is required for the screw. This involves designing the screw's cross-section as a square, polygonal, or circular shape with upper and lower flat sections.

[0003] However, while achieving the anti-rotation function of the lead screw, existing technologies only use a single bushing and modify the shape of the bushing's inner hole to achieve this function. Furthermore, because the lead screw's cross-section is square or circular with upper and lower flat sections, its angular shape causes severe wear on conventional seals during reciprocating motion. Without sealing measures, due to the tiny gap and lubricating oil film between the lead screw and bushing, the lead screw continuously pumps lubricating oil from one end of the bushing to the other during reciprocating motion—a pumping effect. This causes the grease in the bushing's center to continuously decrease, increasing friction between the bushing and the lead screw. In the absence of sealing measures, dust, moisture, and especially extremely fine abrasive particles can enter the grease, further exacerbating lead screw wear under the pumping effect.

[0004] Therefore, it is necessary to propose more reasonable technical solutions to address the technical problems existing in the current technology. Summary of the Invention

[0005] The main objective of this invention is to provide a sealing structure for the output end of a linear joint of a humanoid robot. By optimizing the structure of the components, the joint module can be sealed while ensuring structural strength.

[0006] To achieve the above objectives, the sealing structure adopted in this invention is as follows:

[0007] A sealing structure for the output end of a linear joint of a humanoid robot is provided at the output rod. It includes a front cover that sleeves onto the output rod, and a section rod hole formed on the front cover that has a clearance fit with the output rod and is equipped with a fixing sleeve. The section rod hole is also connected to a second section rod hole for setting an intermediate sealing layer. An outer sealing layer is provided on the outer periphery of the intermediate sealing layer. The inner end of the intermediate sealing layer faces the inner port of the second section rod hole, and the outer end of the intermediate sealing layer faces the outer port of the second section rod hole. An end cap is provided at the outer port of the second section rod hole to close and press against the intermediate sealing layer. An inner sealing layer is provided on the output rod opposite to the intermediate sealing layer.

[0008] The aforementioned output end sealing structure utilizes the gap between the fixed sleeve and the output rod to place lubricating grease, forming a sealing fit at the first rod hole; simultaneously, the cooperation of the outer sealing layer, the middle sealing layer, and the inner sealing layer forms a sealing fit at the second rod hole, thus forming a sealing structure inside the front cover. This structure can guide and lock the lubricating grease on the output rod, ensuring the lubrication requirements of the output rod while preventing lubricating grease from overflowing, causing waste and contamination, thereby better ensuring the operational status of the robot joint.

[0009] Furthermore, the fixing kit can be configured in various forms and is not limited to a single one. Here, we optimize and propose one feasible option: the fixing sleeve includes a fixing bushing, the outer wall of which is interference-fitted with a section of rod hole, and the inner hole of which is clearance-fitted with the output rod. In this configuration, the fixing bushing has a cylindrical structure, and its inner hole is a circular hole coaxial with the output shaft.

[0010] Furthermore, the intermediate sealing layer can be constructed in various forms and is not limited to a single one. Here, we optimize and propose one feasible option: the intermediate sealing layer includes a floating bushing. The inner wall of the floating bushing forms several annular grooves that cooperate with the inner sealing layer to form a labyrinth seal structure. In this scheme, the floating bushing adopts a cylindrical structure with parallel annular grooves inside. Each annular groove corresponds to an inner sealing layer, and the annular grooves and the inner sealing layer form an interlocking structure. When the output rod extends or retracts axially, due to the constraint of the floating bushing, the inner sealing layer shifts axially relative to the output rod, achieving oil scraping or application during this process.

[0011] Furthermore, both the first-stage rod hole and the second-stage rod hole are located inside the front cover and are used to accommodate the output rod. Their mating structure can be configured in various ways; here, we optimize and propose one feasible option: the diameter of the second-stage rod hole is larger than that of the first-stage rod hole, and a step is formed at the connection between the first-stage and second-stage rod holes. An inner end seal is formed at this step and fits tightly against the inner end of the intermediate sealing layer. When using the above solution, the inner end seal includes a sealing ring or sealing ring, which can be made of flexible rubber material. When the intermediate sealing layer is located at the second-stage rod hole, it fits tightly against the sealing ring or sealing ring, thereby maintaining the axial position of the intermediate sealing layer.

[0012] Furthermore, to prevent the lubricating grease on the output rod from overflowing and leaking, the sealing structure inside the two-stage rod hole is optimized. One feasible option is proposed here: the internal sealing layer includes an oil scraper ring with several open grooves formed on it, and the open grooves of adjacent oil scraper rings are staggered. When using the above solution, the oil scraper ring can restrict the grease on the output rod, preventing it from overflowing, and can also scrape the output rod to achieve the application of lubricating grease.

[0013] Furthermore, to enhance the sealing performance of the lubricating grease, an external sealing layer is used. One feasible option is proposed here: the external sealing layer includes an outer end seal, and an outer end annular groove is formed on the inner wall of the two-section rod hole to accommodate the outer end seal. When adopting the above scheme, the outer end seal can be an annular structure, set in the outer end groove, and provide auxiliary sealing for the outer end position of the two-section rod hole.

[0014] Furthermore, in some designs, the inner end seal and the outer end seal form a Gladley ring.

[0015] Furthermore, during operation, periodic maintenance is required to maintain the amount of lubricating grease and provide sufficient lubrication for the internal output rod. One feasible option is proposed here: the front cover is equipped with an oil injection structure, which includes an oil injection hole on the front cover and a plug for opening and closing the oil injection hole. When adopting the above solution, the front cover includes a first-section structure and a second-section structure. The rod hole in the first section is located within the first-section structure, and the rod hole in the second section is located within the second-section structure. The oil injection hole is located on the second-section structure and injects oil into the rod hole in the second section. The plug is used to control the opening and closing of the oil injection hole.

[0016] Furthermore, the output rod can be constructed in various forms. During rotation, it cooperates with a first-section rod hole and a second-section rod hole to achieve rotation, as well as axial relative displacement and sealing of lubricating grease. Its structure is not limited to a single type. Here, we optimize and propose one feasible option: The output rod includes a smooth rod section, and the internal sealing layer forms a sleeve hole that mates with the smooth rod section. The smooth rod section and the sleeve hole are interlocked and relatively fixed in the circumferential direction. When adopting the above scheme, the output rod also includes a threaded section. The smooth rod section and the threaded section are coaxially connected and achieve rotation. The threaded section cooperates with the external thread structure to achieve axial displacement, thereby realizing the output of axial force.

[0017] Furthermore, to maintain the stability and reliability of the sealing structure during rotation, the structure of the output rod is optimized. One feasible option is proposed here: the side surface of the output rod includes a side arc surface and a side plane, and the sleeve hole correspondingly forms an arc surface segment and a plane segment. When the above scheme is adopted, the arc surface segment corresponds to and fits against the arc surface of the output rod, and the plane segment corresponds to and fits against the plane of the output rod, thereby realizing the synchronous rotation of the output rod and the oil scraper in the circumferential direction.

[0018] Furthermore, to better prevent lubricating grease overflow and ensure the lubrication capability of the output rod, the internal sealing layer is optimized as follows: the sleeve hole forms an inclined angle in one direction. When the polished rod section and the internal sealing layer move relative to each other in the first direction, the internal sealing layer scrapes the grease to prevent overflow; when the polished rod section and the internal sealing layer move relative to each other in the second direction, the internal sealing layer applies grease to the polished rod section to provide lubrication. In this scheme, the internal sealing layer is an oil scraper ring, with an outward-facing inclined surface at the end face of the sleeve hole and an inward-facing inclined surface inside the sleeve hole.

[0019] Compared with the prior art, some of the beneficial effects of the technical solution disclosed in this invention include:

[0020] This invention provides a stable sealing structure by setting a first rod hole and a second rod hole inside the front cover, and forming a fixed sealing element, an outer sealing layer, an intermediate sealing layer and an inner sealing layer. This structure can meet the lubrication requirements of the output rod while preventing lubricating grease from overflowing from the output rod, thereby avoiding material waste and external pollution. It can also avoid frequent maintenance, improve ease of use, and enhance the effective use of the joint structure. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the front cover sealing sub-assembly.

[0023] Figure 2 This is a schematic diagram of the cross-section of the front cover sealing sub-assembly.

[0024] Figure 3 This is a schematic diagram of the oil scraper ring installation.

[0025] Figure 4 This is a schematic diagram of the cross-section of the fixed bushing.

[0026] Figure 5 This is a schematic diagram of the cross-section of the grease nipple.

[0027] Figure 6 This is a schematic diagram of the cross-section of the floating bushing and the Glyd ring.

[0028] Figure 7 This is a schematic diagram of the fixed bushing structure.

[0029] Figure 8 This is a schematic diagram of a floating bushing structure.

[0030] Figure 9 This is a schematic diagram of the oil scraper ring structure.

[0031] Figure 10 This is a schematic diagram of the front cover structure.

[0032] In the above diagram, the meanings of each label are as follows:

[0033] 1. Front cover; 101. Single-section structure; 102. Two-section structure; 2. Fixed bushing; 201. Inner arc surface; 202. Inner plane; 3. Floating bushing; 301. Annular inner groove; 4. Oil injection structure; 5. Oil scraper ring; 501. Solid section; 502. Open section; 503. Outward bevel; 504. Inward bevel; 505. Open groove; 6. External sealing layer; 7. End cover; 8. Fastener; 9. Output rod; 901. Side plane. Detailed Implementation

[0034] The following description, in conjunction with the accompanying drawings and specific embodiments, further illustrates this embodiment.

[0035] In view of the problem that lubricating material overflows at the joint structure in the prior art, affecting the normal operation of the joint structure, the following embodiments are optimized and overcome the defects of the prior art.

[0036] Example

[0037] like Figures 1-10 As shown, this embodiment provides a sealing structure for the output end of a linear joint of a humanoid robot, which is located at the output rod 9. It includes a front cover 1 that fits into the output rod 9. The front cover 1 has a section rod hole that is clearance-fitted to the output rod 9 and has a fixing sleeve. The section rod hole is also connected to a second section rod hole for setting an intermediate sealing layer. An outer sealing layer 6 is provided on the outer periphery of the intermediate sealing layer. The inner end of the intermediate sealing layer faces the inner port of the second section rod hole, and the outer end of the intermediate sealing layer faces the outer port of the second section rod hole. An end cap 7 is provided at the outer port of the second section rod hole to close and press against the intermediate sealing layer. An inner sealing layer is provided on the output rod 9 opposite to the intermediate sealing layer.

[0038] Preferably, in this embodiment, the end cover 7 is connected and fixed to the front cover 1 by fasteners 8, and the fasteners 8 can be bolts.

[0039] The output end sealing structure disclosed in this embodiment uses the gap between the fixed sleeve and the output rod 9 to place lubricating grease, forming a sealing fit at the first rod hole; at the same time, the cooperation of the outer sealing layer 6, the middle sealing layer and the inner sealing layer forms a sealing fit at the second rod hole, thereby forming a sealing structure inside the front cover 1, which can guide and lock the lubricating grease on the output rod 9, ensuring the lubrication needs of the output rod 9, and avoiding the waste and pollution caused by the overflow of lubricating grease, thus better ensuring the operation of the robot joint.

[0040] The fixing kit can be configured in various forms and is not limited to a single one. This embodiment optimizes and adopts one feasible option: the fixing sleeve includes a fixing bushing 2, the outer wall surface of the fixing bushing 2 is interference-fitted with a section of rod hole, and the inner hole of the fixing bushing 2 is clearance-fitted with the output rod 9. When the above solution is adopted, the fixing bushing 2 adopts a cylindrical structure, and the inner hole surface of the fixing bushing 2 is a circular hole and is coaxially arranged with the output shaft.

[0041] Preferably, in this embodiment, the inner hole of the fixing bushing 2 forms an inner arc surface 201 and an inner plane 202 that correspond to and cooperate with the output rod 9.

[0042] The intermediate sealing layer can be constructed in various forms and is not limited to a single one. This embodiment optimizes and adopts one feasible option: the intermediate sealing layer includes a floating bushing 3, the inner wall of which forms several annular inner grooves 301, which cooperate with the inner sealing layer to form a labyrinth sealing structure. When the above scheme is adopted, the floating bushing 3 adopts a cylindrical structure, with its internal annular inner grooves 301 arranged in parallel. Each annular inner groove 301 corresponds to one inner sealing layer, and the annular inner grooves 301 and the inner sealing layer form an interlocking structure. When the output rod 9 extends or retracts axially, due to the constraint of the floating bushing 3, the inner sealing layer shifts axially relative to the output rod 9, achieving oil scraping or application during this process.

[0043] Both the first-stage rod hole and the second-stage rod hole are located inside the front cover 1 and are used to accommodate the output rod 9. Their mating structure can be configured in various ways; this embodiment optimizes the design and adopts one feasible option: the diameter of the second-stage rod hole is larger than that of the first-stage rod hole, and a step is formed at the connection between the first-stage and second-stage rod holes. An inner end seal is formed at the step and fits tightly against the inner end of the intermediate sealing layer. When using the above solution, the inner end seal includes a sealing ring or sealing ring, which can be made of flexible rubber material. When the intermediate sealing layer is located at the second-stage rod hole, it fits tightly against the sealing ring or sealing ring, thereby maintaining the axial position of the intermediate sealing layer.

[0044] To prevent lubricating grease from overflowing and leaking from the output rod 9, the sealing structure inside the two-section rod hole is optimized. This embodiment employs one feasible option: the internal sealing layer includes an oil scraper ring 5, with several open grooves 505 formed on the oil scraper ring 5, and the open grooves 505 of adjacent oil scraper rings 5 ​​are staggered. Using the above solution, the oil scraper ring 5 can restrict the grease on the output rod 9, preventing it from overflowing, and can also scrape the output rod 9 to achieve lubricating grease application.

[0045] like Figure 3 As shown, the opening grooves 505 of the two oil scraper rings 5 ​​are misaligned with each other, forming a staggered structure. On one cross section, the open cross section 502 and the solid cross section 501 of the two adjacent oil scraper rings 5 ​​are shown.

[0046] In terms of sealing control of the lubricating grease, the sealing performance is further enhanced by an external sealing layer 6. This embodiment employs one feasible option: the external sealing layer 6 includes an outer end seal, and an outer end annular groove is formed on the inner wall of the two-section rod hole to accommodate the outer end seal. When using the above scheme, the outer end seal can have an annular structure, positioned within the outer end groove, and provide auxiliary sealing to the outer end position of the two-section rod hole.

[0047] In some designs, the inner and outer end seals form a Gladley ring.

[0048] During operation, periodic maintenance is required to maintain the amount of lubricating grease and provide sufficient lubrication for the internal output rod 9. This embodiment employs one feasible option: the front cover 1 is equipped with an oil injection structure 4, which includes an oil injection hole on the front cover 1 and a plug for opening and closing the oil injection hole. When using the above solution, the front cover 1 includes a first section structure 101 and a second section structure 102. The first section rod hole is located within the first section structure 101, and the second section rod hole is located within the second section structure 102. The oil injection hole is located on the second section structure 102 and injects oil into the second section rod hole; the plug is used to control the opening and closing of the oil injection hole.

[0049] The output rod 9 can be constructed in various forms. During rotation, it cooperates with a first-section rod hole and a second-section rod hole to achieve rotation, as well as axial relative displacement and sealing of lubricating grease. Its structure is not limited to a single form. This embodiment optimizes and adopts one feasible option: the output rod 9 includes a smooth rod section, and the internal sealing layer forms a sleeve hole that mates with the smooth rod section. The smooth rod section and the sleeve hole are interlocked and relatively fixed in the circumferential direction. When adopting the above scheme, the output rod 9 also includes a threaded section. The smooth rod section and the threaded section are coaxially connected and achieve rotation. The threaded section cooperates with the external thread structure to achieve axial displacement, thereby realizing the output of axial force.

[0050] To maintain the stability and reliability of the sealing structure during relative displacement, the structure of the output rod 9 is optimized. This embodiment employs one feasible option: the side surface of the output rod 9 includes a side arc surface and a side plane 901, with corresponding arc segment and plane segment formed within the sleeve hole. When the above scheme is adopted, the arc segment corresponds to and fits against the arc surface of the output rod 9, and the plane segment corresponds to and fits against the plane of the output rod 9, thereby achieving relative displacement between the output rod 9 and the oil scraper in the axial direction.

[0051] To better prevent lubricating grease overflow and ensure the lubrication capability of the output rod 9, this embodiment optimizes the internal sealing layer: the sleeve hole forms an inclined angle in one direction. When the polished rod section and the internal sealing layer move relative to each other in the first direction, the internal sealing layer scrapes the grease to prevent overflow; when the polished rod section and the internal sealing layer move relative to each other in the second direction, the internal sealing layer applies grease to the polished rod section to provide lubrication. In this scheme, the internal sealing layer is an oil scraper ring 5. The end face of the sleeve hole of the oil scraper ring 5 forms an outward inclined surface 503, and the inside of the sleeve hole of the oil scraper ring 5 forms an inward inclined surface 504.

[0052] The above are the embodiments listed in this example; however, this example is not limited to the optional embodiments described above; those skilled in the art can arbitrarily combine the above methods to obtain other various embodiments; anyone can derive other various forms of embodiments under the guidance of this example. The above specific embodiments should not be construed as limiting the scope of protection of this example; the scope of protection of this example should be determined by the claims.

Claims

1. A sealing structure for the output end of a linear joint of a humanoid robot, disposed at the output rod (9), characterized in that: The device includes a front cover (1) that fits into the output rod (9). The front cover (1) has a rod hole that fits into the output rod (9) with a clearance and is provided with a fixing sleeve. The rod hole is also connected to a second rod hole for setting an intermediate sealing layer. An outer sealing layer (6) is provided on the outer periphery of the intermediate sealing layer. The inner end of the intermediate sealing layer faces the inner port of the second rod hole, and the outer end of the intermediate sealing layer faces the outer port of the second rod hole. An end cap (7) is provided on the outer port of the second rod hole to close and press against the intermediate sealing layer. An inner sealing layer is provided on the output rod (9) that is opposite to the intermediate sealing layer. The intermediate sealing layer includes a floating bushing (3), the inner wall of which forms several annular inner grooves (301) and cooperates with the internal sealing layer to form a labyrinth sealing structure. The diameter of the second rod hole is larger than that of the first rod hole. A step is formed at the connection between the first rod hole and the second rod hole. An inner end seal is formed at the step and fits tightly against the inner end of the intermediate sealing layer. The internal sealing layer includes an oil scraper ring (5), and several opening grooves (505) are formed on the oil scraper ring (5), with the opening grooves (505) of adjacent oil scraper rings (5) being misaligned with each other; The external sealing layer (6) includes an outer end seal, and an outer end annular groove is formed on the inner wall of the two-section rod hole to accommodate the outer end seal; The front cover (1) is provided with an oil injection structure (4), which includes an oil injection hole provided on the front cover (1) and a plug for opening and closing the oil injection hole; The output rod (9) includes a smooth rod section, and the inner sealing layer forms a sleeve hole that mates with the smooth rod section. The smooth rod section and the sleeve hole are interlocked and relatively fixed in the circumferential direction. The side surface of the smooth rod section includes an arc surface and a flat surface, and the arc surface section and the flat surface section are formed correspondingly inside the sleeve hole; The bushing is tilted in one direction. When the polished rod section and the inner sealing layer move relative to each other in the first direction, the inner sealing layer scrapes oil to prevent grease from overflowing. When the polished rod section and the inner sealing layer move relative to each other in the second direction, the inner sealing layer applies grease to the polished rod section to provide lubrication.

2. The sealing structure for the output end of the linear joint of the humanoid robot according to claim 1, characterized in that: The fixed sleeve includes a fixed bushing (2), the outer wall of the fixed bushing (2) is interference-fitted with a section of rod hole, and the inner hole of the fixed bushing (2) is clearance-fitted with the output rod (9).

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