Oil injection pin shaft with guard ring structure

Abstract

The utility model provides a kind of oiling pin shaft with protective ring structure, including the cylindrical main pin being equipped with axial oiling hole and radial oil outlet hole, and the oiling hole oil inlet has internal thread and is connected with standard oil nozzle by screw thread;Annular steel plate fixing plate is sleeved on the outer circumferential surface of main pin, and the end away from main pin is equipped with protective ring formed by turning from seamless tube, and protective ring surrounds oil nozzle to form external shielding structure.The lower end of main pin has assembly chamfer, and fixing plate has fixing hole.The utility model has the advantages that: first, through the cooperation of oiling hole and oil outlet hole and oil nozzle, lubricating grease can be accurately injected, the lubrication and rust prevention performance are improved, and the service life is prolonged.Second, protective ring can block foreign matter collision oil nozzle in all directions, strengthen oil nozzle protection, ensure maintenance reliability, and reduce equipment maintenance cost.

Description

Technical Field

[0001] This utility model relates to the field of engineering machinery, specifically to an oil-fillable pin shaft with a protective ring structure. Background Technology

[0002] In the field of construction machinery, the pin, as a core component for achieving the rotational connection of parts, is widely used in the hinged structures of various grippers, robotic arms, and other equipment. Its main function is to enable connected parts to rotate flexibly around the hinge point through its own rigid support, thereby realizing the operation of the equipment.

[0003] However, existing pins have many technical shortcomings in practical applications:

[0004] Wear and corrosion are prominent issues: The pin is subjected to high-frequency rotational friction over a long period. Its surface and the hinged parts of the connected components are prone to wear due to direct metal-to-metal contact, leading to increased clearance. This not only reduces the pin's service life but also affects the smoothness and accuracy of component rotation. Furthermore, construction machinery often operates in open-air environments, exposing the pin to rain, sun, dust, and corrosive media, making it highly susceptible to corrosion. In severe cases, this can cause parts to jam, preventing normal rotation and even leading to equipment malfunction.

[0005] Insufficient protection of grease nipples: To mitigate wear and corrosion, existing pins are typically equipped with grease nipples for periodic grease injection. However, these nipples are mostly exposed. Due to the harsh operating environment of construction machinery, they frequently collide or scrape with hard objects such as rocks, concrete blocks, and debris. Exposed grease nipples are easily damaged by impacts (e.g., deformation, breakage, blockage). When a grease nipple fails, grease cannot be injected properly, accelerating wear and corrosion of the pin and related parts. This ultimately leads to premature pin failure, requiring frequent replacement and repair, increasing maintenance costs, reducing operational efficiency, and wasting resources.

[0006] Therefore, how to design a pin structure that can achieve both efficient lubrication and rust prevention, and effectively protect the grease nipple, has become a technical problem that urgently needs to be solved in this field. Utility Model Content

[0007] The technical problem to be solved by this utility model is to overcome the above-mentioned technical defects and provide an oil-fillable pin shaft with a protective ring structure.

[0008] To solve the above-mentioned technical problems, the technical solution provided by this utility model is: an oil-fillable pin shaft with a protective ring structure, comprising:

[0009] A cylindrical kingpin has an axial oil injection hole and a radial oil outlet hole inside, and the oil inlet of the oil injection hole has an internal thread;

[0010] A fixing plate is fitted onto the outer circumference of the kingpin;

[0011] The protective ring is located at the end of the fixing plate furthest from the kingpin;

[0012] The standard grease nipple is threaded to the internal thread of the grease filling hole;

[0013] The protective ring surrounds the oil injection nozzle and forms an external shielding structure.

[0014] As a preferred embodiment of this application, the fixing plate is a steel plate with connecting holes, the inner diameter of which matches the outer diameter of the main pin and is welded and fixed.

[0015] As a preferred embodiment of this application, the protective ring is machined from a seamless tube, and its inner diameter is larger than the maximum outer diameter of the oil injection nozzle.

[0016] As a preferred embodiment of this application, the oil injection hole is a deep hole with a diameter of ∮8.7mm and a depth of 60mm, with an internal thread of 1 / 8-27 specification and a depth of 10mm.

[0017] As a preferred embodiment of this application, the oil outlet hole is a through hole with a diameter of ∮4.8mm, which is set perpendicular to the axis of the kingpin and connects the oil injection hole with the outside of the kingpin.

[0018] As a preferred embodiment of this application, the lower end of the main pin is provided with a 3×45° assembly chamfer.

[0019] As a preferred embodiment of this application, the fixing plate has a thickness of 6mm and is formed by laser cutting.

[0020] As a preferred embodiment of this application, the fixing plate is provided with fixing holes for bolts to pass through.

[0021] As a preferred embodiment of this application, the axial height of the protective ring is greater than the installation height of the oil injection nozzle.

[0022] The advantages of this utility model compared with the prior art are as follows:

[0023] 1. Improves lubrication and rust prevention performance, extending service life.

[0024] This invention features an axial oil injection hole and a radial oil outlet hole inside a cylindrical kingpin. Combined with a standard grease nipple 4, grease can be precisely injected into the hinged joint between the kingpin and the parts. The grease is evenly distributed on the friction surface through the oil outlet hole, forming a continuous lubricating film that significantly reduces the coefficient of rotational friction and minimizes wear. Simultaneously, the grease isolates the kingpin from air, moisture, and corrosive media, effectively inhibiting corrosion of the kingpin and connected parts, and greatly extending the service life of the kingpin and the entire hinged structure.

[0025] 2. Enhance the protection of the grease nipple to ensure maintenance reliability.

[0026] A protective ring surrounds the grease injector, forming an external shielding structure. Machined from seamless tubing with an axial height greater than the injector's installation height, it effectively blocks direct impacts from stones, debris, and other foreign objects, preventing damage to the injector from collisions. This design ensures the long-term effective operation of the injector, guarantees stable grease injection, reduces the frequency of maintenance and replacement due to injector failure, and lowers equipment maintenance costs. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of an oil-fillable pin with a protective ring structure according to this application;

[0028] Figure 2 This is a side view schematic diagram of an oil-fillable pin shaft with a protective ring structure according to this application;

[0029] Figure 3 This is a schematic diagram of the cylindrical kingpin in this application.

[0030] Figure 4 This is a schematic diagram of the installation structure of an oil-fillable pin with a protective ring structure according to this application.

[0031] As shown in the figure: 1. Cylindrical kingpin, 11. Axial oil injection hole, 12. Radial oil outlet hole, 13. Chamfer, 2. Fixing plate, 21. Fixing hole, 3. Protective ring, 4. Oil injection nozzle, 5. First part, 6. Second part, 7. Bolt, 8. Washer. Detailed Implementation

[0032] The present invention will now be described in further detail with reference to the accompanying drawings.

[0033] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings. Identical components are indicated by the same reference numerals.

[0034] It should be noted that the terms “front,” “back,” “left,” “right,” “up,” and “down” used in the following description refer to the directions shown in the attached diagram, while the terms “inside” and “outside” refer to the directions toward or away from the geometric center of a specific component, respectively.

[0035] To make the content of this utility model easier to understand, the technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0036] Reference Appendix Figure 1 -Appendix Figure 4 An oil-fillable pin with a protective ring structure, comprising:

[0037] The cylindrical main pin 1 has an axial oil injection hole 11 and a radial oil outlet hole 12 inside. The oil inlet of the oil injection hole 11 is provided with an internal thread.

[0038] Fixing plate 2 is sleeved on the outer circumference of main pin 1;

[0039] The protective ring 3 is located at the end of the fixing plate 2 away from the main pin 1;

[0040] Standard grease nipple 4 is threadedly connected to the internal thread of grease hole 11;

[0041] The protective ring 3 surrounds the oil injection nozzle 4 and forms an external shielding structure.

[0042] In one embodiment, the fixing plate 2 is a steel plate with connecting holes, the inner diameter of which matches the outer diameter of the main pin 1 and is welded and fixed.

[0043] The structural design of the connecting hole forms a high-precision fit with the outer diameter of the main pin 1. A rigid connection is achieved through welding, which evenly transfers the load borne by the fixing plate 2 to the main pin 1. This effectively prevents relative displacement due to loosening of the connection during long-term stress and component rotation, thus ensuring the overall stability of the pin shaft structure. This welding fixing method significantly improves the assembly accuracy of the pin shaft and the connected parts, reduces vibration wear caused by excessive clearance, and enhances the fatigue resistance of the pin shaft under complex working conditions, extending its service life.

[0044] In one embodiment, the protective ring 3 is machined from a seamless tube, with its inner diameter larger than the maximum outer diameter of the grease nipple 4. The seamless tube material has a uniform metallographic structure and excellent mechanical properties, with no weld defects. After machining, it achieves high-precision dimensional tolerances and surface finish, ensuring a smooth inner wall of the protective ring 3 and preventing scratch damage to the grease nipple 4. The design of the protective ring 3's inner diameter being larger than the maximum outer diameter of the grease nipple 4 provides ample space for lubrication operations, facilitating quick docking of the grease gun and grease nipple 4 without affecting daily lubrication maintenance efficiency. Furthermore, this design creates a buffer gap between the protective ring 3 and the grease nipple 4, effectively absorbing the energy of foreign object impacts. Even in situations involving rock collisions or flying debris during engineering machinery operations, the structural strength of the protective ring 3 can prevent external forces from directly acting on the grease nipple 4, significantly reducing the risk of deformation or breakage.

[0045] In one embodiment, the oil injection hole 11 is a deep hole with a diameter of ∮8.7mm and a depth of 60mm, with an internal thread of 1 / 8-27 specification and a depth of 10mm. The ∮8.7mm hole diameter design balances grease flow efficiency and the structural strength of the main pin 1: it ensures smooth grease flow within the hole, meeting the needs of rapid oil injection, while avoiding excessive weakening of the main pin 1's cross-section due to an excessively large hole diameter, ensuring it can still withstand the heavy-duty working conditions of engineering machinery. The 60mm depth allows grease to reach the critical hinged lubrication area inside the main pin 1, covering the core friction surfaces of the first part 5 and the second part 6, ensuring sufficient lubrication without dead zones. The 1 / 8-27 specification internal thread forms a precise match with the standard grease injection nozzle 4, and the 10mm thread depth ensures a tight connection between the grease injection nozzle 4 and the oil injection hole 11, effectively preventing grease leakage during high-pressure oil injection, while also enhancing the pull-out resistance of the grease injection nozzle 4, avoiding detachment due to external pulling, and ensuring the stability of long-term lubrication performance.

[0046] In one embodiment, the oil outlet 12 is a through hole with a diameter of ∮4.8mm, perpendicular to the axis of the main pin 1, connecting the oil injection hole 11 to the outside of the main pin 1. The perpendicular orientation to the axis of the main pin 1 ensures a short and smooth flow path for the grease from the oil injection hole 11 to the oil outlet 12, minimizing flow resistance and ensuring that the grease is quickly and evenly delivered to the hinged joint outside the main pin 1 under injection pressure. The ∮4.8mm hole diameter is optimized to ensure effective grease penetration, fully wetting the hinged surfaces of the first part 5 and the second part 6 to form a continuous lubricating film and significantly reduce the coefficient of rotational friction; it also avoids excessive grease loss due to an excessively large hole diameter, reducing grease consumption and maintenance costs. Meanwhile, the through hole can precisely guide the grease in the oil injection hole 11 to the friction area. When the first part 5 rotates with the pin as the pivot point, the grease is evenly distributed with the movement, which not only plays a lubricating role, but also isolates air and moisture, effectively preventing corrosion of the pivot point of the pin, the first part 5 and the second part 6, and extending the service life of each component.

[0047] In one embodiment, the lower end of the main pin 1 is provided with a 3×45° assembly chamfer 13. The 3×45° assembly chamfer 13 provides precise guidance during the pin installation process. When the main pin 1 passes through the mounting holes of the first part 5 and the second part 6, it effectively eliminates hard contact between the hole opening and the end of the main pin 1, guiding the main pin 1 smoothly into the hole, significantly reducing assembly resistance and improving installation efficiency. Simultaneously, the chamfer structure prevents the sharp edge of the lower end of the main pin 1 from scratching the hole wall, protecting the surface accuracy of the hole and reducing the increase in fit clearance due to assembly damage, thereby ensuring the rotational accuracy of the hinged joint. Furthermore, the chamfer eliminates stress concentration points at the end of the main pin 1, reducing the risk of fatigue cracks at the end under long-term alternating load conditions, and extending the service life of the main pin 1. For assembly personnel, the chamfer also prevents scratches caused by sharp edges, improving the safety of the operation process.

[0048] In one embodiment, the fixing plate 2 is 6mm thick and is formed by laser cutting. The 6mm thickness achieves a balance between strength and lightweight design: sufficient thickness ensures that the fixing plate 2 will not bend, deform, or break when subjected to bolt preload and loads transmitted by the parts, stably constraining the axial and radial positions of the main pin 1 and ensuring the structural stability of the hinged joint; simultaneously, compared to thicker steel plates, the 6mm thickness reduces the overall weight of the pin, conforming to the trend of lightweight design in engineering machinery and reducing equipment operating energy consumption. Laser cutting offers high precision, allowing the dimensional tolerance of the fixing plate 2 to be controlled within ±0.1mm, ensuring precise matching between its inner diameter and the outer diameter of the main pin 1, improving assembly accuracy; furthermore, the heat-affected zone of laser cutting is extremely small, not damaging the original mechanical properties of the steel plate, ensuring that the strength and toughness of the fixing plate 2 are not compromised, thereby improving the reliability of the connection between the pin and the parts.

[0049] In one embodiment, the fixing plate 2 is provided with fixing holes 21 for bolts to pass through. The fixing holes 21 provide a standardized positioning reference for the bolt connection, ensuring that the bolts can accurately pass through the fixing plate 2 and form a tight fit with the connected second part 6. The preload of the bolts axially fixes the pin, effectively preventing axial movement or dislodgement of the pin during the rotation of the first part 5, thus ensuring the stability of the joint. The dimensions of the fixing holes 21 are strictly matched to the bolt specifications, ensuring a uniform distribution of the preload in the bolt connection and preventing deformation of the fixing plate 2 due to excessive local stress. Simultaneously, the detachability of the bolt connection makes the installation, maintenance, and replacement of the pins more convenient, reducing subsequent maintenance costs.

[0050] In one embodiment, the axial height of the protective ring 3 is greater than the installation height of the oil nozzle 4. This design, where the axial height of the protective ring 3 is greater than the installation height of the oil nozzle 4, forms a comprehensive three-dimensional protective barrier, effectively blocking impacts from above, sides, and angles. Whether it's common issues in construction machinery operations such as rolling rocks and flying gravel, or accidental scraping during equipment operation, it prevents the oil nozzle 4 from directly bearing external forces. This design, while ensuring protective effectiveness, also provides sufficient operating space, allowing the oil gun to smoothly connect to the oil nozzle 4 from the inside of the protective ring 3 during oil filling without affecting normal oil filling operations.

[0051] Working principle: This oilable pin with a protective ring structure is ingeniously designed from installation to use, and can achieve the functions of lubrication, rust prevention and component protection.

[0052] During installation, the first step is the welding and assembly of the oilable pin itself. A 6mm thick fixing plate 2, laser-cut to match the outer diameter of the cylindrical main pin 1, is fitted onto the main pin 1, and welded together to ensure even load distribution and structural stability. Next, a protective ring 3, machined from seamless tubing and used to surround the standard oil filler nozzle 4, is installed in the appropriate position, completing the welding and assembly of the entire oilable pin. Then, the assembled pin is smoothly inserted into the round holes of the first part 5 and the second part 6 using the 3×45° chamfer 13 at the lower end of the main pin 1. The chamfer reduces assembly resistance and prevents scratch damage. Finally, bolts 7 and washers 8 are passed through the fixing holes 21 on the fixing plate 2 to fix the pin to the second part 6, preventing axial movement or detachment.

[0053] In operation, for lubrication, grease is injected through the standard grease injector 4. The grease flows downward through the axial injection hole 11 (8.7mm diameter, 60mm depth) in the main pin 1, and then flows out through the radial outlet hole 12 (4.8mm diameter), perpendicular to the axis of the main pin 1, precisely reaching the hinged friction area between the first part 5 and the main pin 1, reducing the coefficient of rotational friction and minimizing wear. For rust prevention, the injected grease is evenly distributed as the first part 5 rotates, isolating air and moisture and preventing corrosion at the hinged joint of the main pin 1, the first part 5, and the second part 6. The protective ring 3 has an inner diameter larger than the maximum outer diameter of the grease injector 4 and a higher axial height, forming a comprehensive three-dimensional protective barrier. This effectively blocks impacts from falling rocks and flying gravel during construction machinery operation, preventing damage to the grease injector 4 and ensuring normal lubrication and long-term stable operation.

[0054] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A lubricated pin with a protective ring structure, characterized in that, include: A cylindrical main pin (1) has an axial oil injection hole (11) and a radial oil outlet hole (12) inside. The oil inlet of the oil injection hole (11) is provided with an internal thread. The fixing plate (2) is fitted onto the outer circumferential surface of the main pin (1); A protective ring (3) is located at the end of the fixing plate (2) away from the main pin (1); A standard grease nipple (4) is threadedly connected to the internal thread of the grease hole (11); The protective ring (3) surrounds the oil injection nozzle (4) and forms an external shielding structure.

2. The oil-fillable pin shaft with a protective ring structure according to claim 1, characterized in that: The fixing plate (2) is a steel plate with connecting holes, the inner diameter of which matches the outer diameter of the main pin (1) and is welded and fixed.

3. The oil-fillable pin shaft with a protective ring structure according to claim 1, characterized in that: The protective ring (3) is machined from a seamless tube, and its inner diameter is larger than the maximum outer diameter of the oil injection nozzle (4).

4. The oil-fillable pin shaft with a protective ring structure according to claim 1, characterized in that: The oil injection hole (11) is a deep hole with a diameter of ∮8.7mm and a depth of 60mm. The internal thread is of 1 / 8-27 specification and has a depth of 10mm.

5. The oil-fillable pin shaft with a protective ring structure according to claim 1, characterized in that: The oil outlet hole (12) is a through hole with a diameter of ∮4.8mm, which is set perpendicular to the axis of the main pin (1) and connects the oil injection hole (11) with the outside of the main pin (1).

6. The oil-fillable pin shaft with a protective ring structure according to claim 1, characterized in that: The lower end of the main pin (1) is provided with a 3×45° assembly chamfer (13).

7. The oil-fillable pin shaft with a protective ring structure according to claim 1, characterized in that: The fixing plate (2) is 6mm thick and is formed by laser cutting.

8. The oil-fillable pin shaft with a protective ring structure according to claim 1, characterized in that: The fixing plate (2) is provided with fixing holes (21) for bolts to pass through.

9. The oil-fillable pin with a protective ring structure according to any one of claims 1-8, characterized in that: The axial height of the protective ring (3) is greater than the installation height of the oil nozzle (4).

Images