Internal and external free rotating pin sleeve structure and lubricated chain

Abstract

The application discloses an inner-outer free rotation pin sleeve structure and a lubricated chain. The inner-outer free rotation pin sleeve structure comprises a pin shaft, an outer layer pin sleeve, an inner layer pin sleeve and an end plug. A radial gap is arranged between the outer circle of the inner layer pin sleeve and the inner circle of the outer layer pin sleeve to form a first lubricating cavity. A radial gap is arranged between the outer circle of the pin shaft and the inner circle of the inner layer pin sleeve to form a second lubricating cavity. An oil storage cavity is arranged in the pin shaft. An oil injection hole is arranged at one end of the pin shaft and communicates with the oil storage cavity. An oil distribution hole is arranged on the outer circle of the pin shaft and communicates the oil storage cavity with the second lubricating cavity. The lubricated chain comprises outer chain plates, inner chain plates and the inner-outer free rotation pin sleeve structure. The lubricating effect of the pin shaft, the outer layer pin sleeve and the inner layer pin sleeve is improved, the wear problem is reduced, the sealing effect is good, the axial position of the inner layer pin sleeve is limited by a thrust bushing, the storage of lubricating oil is realized through the oil storage cavity, and the convenience of oil injection maintenance is improved.

Description

Technical Field

[0001] This invention relates to the field of chains, and more particularly to a structure of freely rotating pin sleeves and a lubricated chain. Background Technology

[0002] The main feature of bulldozer lubrication chain bushings is that a certain gap is reserved between the pin and the bushing to form a sealed cavity filled with lubricating oil. This ensures timely lubrication during the equipment's movement and the rotation of the bushings, reducing wear between the pin and the bushing and extending the service life of the lubrication chain.

[0003] During the chain drive process, which lubricates the chain, the drive teeth directly actuate the outer diameter of the chain pin sleeve. Simultaneously, the chain pin sleeve and pin shaft rotate relative to each other and also rotate around the four wheels of the bulldozer, inevitably causing relative slippage between the drive teeth and the outer diameter. When the tooth surface of the drive teeth first contacts the pin sleeve, the pin sleeve undergoes a planar composite motion, while the drive teeth rotate on a fixed axis. The mismatch in tangential linear velocities at the contact point results in momentary impact slippage, which is the main cause of early wear on the tooth surface of the drive teeth and the outer diameter of the pin sleeve.

[0004] During the heavy-load phase when the drive tooth enters the tooth groove and bears the traveling torque, there is only a theoretically instantaneous pure rolling at the meshing node. At other meshing positions, due to the flexible deformation of the track, load fluctuations, and changes in tension, there is always tangential fretting between the tooth surface and the pin sleeve. When the drive tooth is about to disengage from the pin sleeve, the normal load decreases rapidly, and the tangential relative slip increases significantly until the tooth surface and pin sleeve are completely disengaged. If the track tension is too loose or the tooth surface is severely worn, tooth skipping and slippage may also occur at this stage, and the slippage will increase exponentially. Therefore, the wear of the outer diameter of the pin sleeve and the contact area of ​​the drive tooth is one of the main wear characteristics of lubrication chains, which has a significant impact on the overall life of the lubrication chain and also affects the life of the drive tooth.

[0005] Currently, solutions for wear on the outer diameter of the pin bushing and the drive teeth of lubrication chains mainly involve increasing the hardness and carburization depth of the pin bushing. These methods are costly and cannot fundamentally solve the problem. Alternatively, a reversible pin bushing structure can be researched, but this structure is quite complex. Therefore, the existing technical solutions have the following drawbacks: 1. Simply increasing the hardness of the pin sleeve and the depth of the carburized layer cannot completely solve the problem, nor can it solve the problem of excessive wear of the drive teeth; 2. After the pin sleeve wears to a certain depth, it needs to be flipped, which is time-consuming and labor-intensive, and the equipment needs to be shut down. 3. The convertible pin sleeve requires sealing, and the double sealing structure is complex, difficult to assemble, and has poor sealing reliability. It is necessary to replace the forgings of the track links at the same time, and to re-open the mold, which is costly. Adding lubricating oil is also difficult, so improvements are needed. Summary of the Invention

[0006] The purpose of this invention is to provide an internally and externally freely rotating pin sleeve structure and a lubricating chain, which solves the problem of wear and failure caused by sliding friction at the contact point between the chain pin sleeve and the drive teeth during equipment movement, improves the service life of the chain and drive teeth, and facilitates maintenance.

[0007] To achieve this objective, the present invention adopts the following technical solution: A freely rotatable pin sleeve structure includes: a pin shaft, an outer pin sleeve, an inner pin sleeve, and an end plug. The inner pin sleeve is rotatably fitted onto the outer circle of the pin shaft, and the outer pin sleeve is rotatably fitted onto the outer circle of the inner pin sleeve. A radial clearance of 0.15~0.25mm is provided between the outer circle of the inner pin sleeve and the inner circle of the outer pin sleeve to form a first lubrication cavity. A radial clearance is provided between the outer circle of the pin shaft and the inner circle of the inner pin sleeve to form a second lubrication cavity. An oil reservoir is provided in the pin shaft, and an oil injection hole communicating with the oil reservoir is provided at one end of the pin shaft. The end plug is disposed in the oil injection hole. An oil distribution hole communicating with the oil reservoir and the second lubrication cavity is provided on the outer circle of the pin shaft.

[0008] The first lubrication cavity is filled with lithium-based grease, and the oil storage cavity is filled with lubricating oil.

[0009] The inner ring of the inner pin sleeve has inner conical surfaces with a taper of 1:100 to 1:500 at both ends of its inner circle.

[0010] The inner pin sleeve has a lubricating oil groove on its outer circumference.

[0011] The lubricating oil grooves are annular in shape and are spaced apart along the outer circumference of the inner pin sleeve.

[0012] The lubricating oil grooves are strip-shaped and are spaced apart along the outer circumference of the inner pin sleeve.

[0013] The end plug has a limiting ring at its outer circumference, a first annular groove corresponding to the limiting ring in the oil injection hole, a pinhole recessed at the end of the end plug, and an elastic expansion joint communicating with the pinhole at the front end of the end plug.

[0014] The limiting ring has an outer conical surface at its front end, and the limiting ring and the end plug are made of an integrated rubber structure.

[0015] To achieve this objective, the present invention employs the following other technical solution: A lubricating chain includes: an outer chain plate, an inner chain plate, and the aforementioned inner and outer freely rotating pin sleeve structure. The inner chain plate is disposed on both sides of the outer pin sleeve. The inner chain plate has an interference fit mounting hole with the outer circular end of the inner pin sleeve. The outer circular end of the inner pin sleeve is located in the corresponding mounting hole. The outer chain plate is disposed on the outer side of the inner chain plate. The two ends of the pin shaft pass through the corresponding outer chain plate. The inner side of the outer chain plate has a recessed second annular groove located on the outer side of the end of the inner pin sleeve. The second annular groove contains a thrust bushing and a first sealing element sleeved on the outer circle of the thrust bushing. The inner side of the inner chain plate has a recessed third annular groove located on the outer side of the end of the outer pin sleeve. The third annular groove contains a second sealing element.

[0016] The first sealing element is a combined sealing ring, and the second sealing element is a stacked disc spring.

[0017] The beneficial effects of this invention are as follows: A freely rotatable pin sleeve structure and lubrication chain are specially designed with a pin shaft, an outer pin sleeve, and an inner pin sleeve that can rotate relative to each other, forming a first lubrication cavity and a second lubrication cavity. This improves the lubrication effect of the pin shaft, the outer pin sleeve, and the inner pin sleeve, reduces wear problems, avoids premature wear, and prevents leakage through the first and second sealing elements. The thrust bushing is used to axially limit the inner pin sleeve, preventing misalignment and sealing leakage problems. The lubricating oil can also be stored through the oil storage cavity, extending the service life and improving the convenience of oiling and maintenance. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the internal and external freely rotating pin sleeve structure of the present invention; Figure 2 yes Figure 1 Schematic diagram of the inner layer pin sleeve; Figure 3 This is a schematic diagram of the structure of a lubrication chain according to the present invention; Figure 4 This is a schematic diagram of the structure of a lubricating chain after removing the outer pin sleeve according to the present invention. Detailed Implementation

[0019] The following is combined Figures 1 to 4 The technical solution of the present invention will be further illustrated through specific embodiments.

[0020] like Figure 1The illustrated free-rotating pin sleeve structure includes: a pin 300, an outer pin sleeve 100, an inner pin sleeve 200, and an end plug 400. The inner pin sleeve 200 is rotatably fitted onto the outer circle of the pin 300, and the outer pin sleeve 100 is rotatably fitted onto the outer circle of the inner pin sleeve 200. Furthermore, the lengths of the pin 300, the inner pin sleeve 200, and the outer pin sleeve 100 decrease sequentially to facilitate the subsequent assembly of the lubrication chain.

[0021] A radial gap of 0.15~0.25mm is provided between the outer circle of the inner pin sleeve 200 and the inner circle of the outer pin sleeve 100 to form a first lubrication cavity 110. The first lubrication cavity 110 is filled with lithium-based grease to lubricate the outer circle of the inner pin sleeve 200 and the inner circle of the outer pin sleeve 100, thereby reducing wear.

[0022] The inner pin sleeve 200 has a lubricating oil groove 230 on its outer circumference. The structure and distribution of the lubricating oil groove 230 can be in the following two ways: The first type has a ring-shaped structure and is distributed at intervals along the outer circle length of the inner pin sleeve, storing lithium-based grease in segments to extend service life. The second type, such as Figure 2 As shown, the lubricating oil groove 230 has a strip-shaped structure and is distributed at intervals along the outer circumference of the inner pin sleeve 200. Multiple lubricating oil grooves 230 extend along the length direction of the inner pin sleeve 200, making the storage and distribution of lithium-based grease more uniform.

[0023] like Figure 1 As shown, a radial clearance is provided between the outer circle of the pin 300 and the inner circle of the inner sleeve 200, forming a second lubrication cavity 220 for easy lubrication. An oil reservoir 320 is provided in the pin 300, and an oil injection hole 330 communicating with the oil reservoir 320 is provided at one end of the pin 300. The end plug 400 is placed in the oil injection hole 330 to seal the oil injection hole 330 and prevent oil leakage.

[0024] An oil distribution hole 310 is provided on the outer circle of the pin 300, which connects the oil storage cavity 320 and the second lubrication cavity 220. The oil storage cavity 320 is filled with lubricating oil, and the lubricating oil is sent to the second lubrication cavity 220 through the oil distribution hole 310 to lubricate the outer circle of the pin 300 and the inner circle of the inner sleeve 200, thereby reducing the resistance and wear of relative rotation.

[0025] like Figure 2As shown, the inner ends of the inner ring of the inner ring 200 are provided with inner conical surfaces 210 with a taper of 1:100 to 1:500. The design of the inner conical surfaces 210 can not only store more lubricating oil at both ends of the second lubrication cavity 220, improve the end lubrication effect and avoid early wear, but also resist the effect of interference fit deformation during the subsequent lubrication chain assembly process.

[0026] To prevent the end plug 400 from loosening, a limiting ring 420 is provided at the outer circumference of the end plug 400, and a first annular groove 340 corresponding to the limiting ring 420 is provided in the oil injection hole 330 for axial limiting of the end plug 400. In this embodiment, the limiting ring 420 and the end plug 400 adopt an integrated rubber structure, which is elastic. The front end of the limiting ring 420 is provided with an outer conical surface 440 to facilitate the elastic contraction of the limiting ring 420 when it is squeezed into the oil injection hole 330. The limiting ring 420 elastically resets when it passes through the first annular groove 340, achieving self-limitation and preventing loosening.

[0027] like Figure 1 As shown, the end plug 400 has a recessed pin hole 410 at its tail end, and the end plug 400 has an elastic expansion joint 430 communicating with the pin hole 410 at its front end. During the process of the needle of the oil injection needle being squeezed into the elastic expansion joint 430 through the pin hole 410, the elastic expansion joint 430 is opened, which facilitates the injection of lubricating oil into the oil storage cavity 320. After the needle is pulled out, the elastic expansion joint 430 automatically and elastically closes to avoid oil leakage and improve the convenience of oil injection and maintenance.

[0028] like Figure 3 and Figure 4 The lubrication chain shown includes: an outer chain plate 500, an inner chain plate 600, and... Figure 1 and Figure 2 The inner and outer free-rotating pin sleeve structure shown has an inner chain plate 600 disposed on both sides of the outer pin sleeve 100. The inner chain plate 600 is provided with an installation hole 610 that is interference-fitted with the outer circular end of the inner pin sleeve 200. The outer circular end of the inner pin sleeve 200 is located in the corresponding installation hole 610, and the interference fit is achieved, resulting in a stable structure.

[0029] The design of the inner conical surface 210 can not only offset the shrinkage deformation of the inner hole caused by the interference fit between the inner pin sleeve 200 and the mounting hole 610, but also match the flexural deformation of the pin shaft 300, thus improving the ease of assembly and structural reliability.

[0030] The outer link plate 500 is set on the outside of the inner link plate 600. The two ends of the pin 300 pass through the corresponding outer link plate 500 respectively. The pin 300 can be fixed by cotter pins or other means to prevent axial movement and ensure structural stability.

[0031] like Figure 3As shown, a second annular groove 510 is provided in the inner side of the outer chain plate 500, located on the outer side of the end of the inner layer pin sleeve 200. A thrust bushing 800 and a first sealing element 900 sleeved on the outer circle of the thrust bushing 800 are provided in the second annular groove 510. The thrust bushing 800 is used to limit the axial movement of the inner layer pin sleeve 200, so as to avoid skewing and sealing leakage problems.

[0032] In this embodiment, the first sealing element 900 adopts a combined sealing ring. The first sealing element 900 contacts the end face of the inner pin sleeve 200, which effectively avoids the problem of lubricating oil in the second lubrication cavity 220 leaking outward.

[0033] A third annular groove 620 is recessed on the inner side of the inner chain plate 600 and located on the outer side of the end of the outer pin sleeve 100. A second sealing element 700 is provided in the third annular groove 620. In this embodiment, the second sealing element 700 is a stacked butterfly spring. The butterfly spring seals the axial gap of the outer pin sleeve 100 and provides a stable axial preload, which compensates for wear in real time and extends the service life.

[0034] The above description is only a preferred embodiment of the present invention. For those skilled in the art, there will be changes in the specific implementation and application scope based on the ideas of the present invention. The content of this specification should not be construed as a limitation of the present invention.

Claims

1. A freely rotating pin sleeve structure, characterized in that, include: The system comprises a pin, an outer pin sleeve, an inner pin sleeve, and an end plug. The inner pin sleeve is rotatably fitted onto the outer circumference of the pin, and the outer pin sleeve is rotatably fitted onto the outer circumference of the inner pin sleeve. A radial clearance exists between the outer circumference of the inner pin sleeve and the inner circumference of the outer pin sleeve, forming a first lubrication cavity. A radial clearance also exists between the outer circumference of the pin and the inner circumference of the inner pin sleeve, forming a second lubrication cavity. An oil reservoir is provided within the pin, and an oil injection hole communicating with the oil reservoir is provided at one end of the pin. The end plug is disposed in the oil injection hole. The outer circle of the pin shaft is provided with an oil distribution hole that connects the oil storage cavity and the second lubrication cavity. The outer circle of the inner pin sleeve is provided with a lubricating oil groove. The outer end of the end plug is provided with a limiting ring. The oil injection hole is provided with a first annular groove corresponding to the limiting ring. The tail end of the end plug is recessed and provided with a pinhole. The front end of the end plug is provided with an elastic expansion joint that communicates with the pinhole. The front end of the limiting ring is provided with an outer conical surface. The limiting ring and the end plug adopt an integrated rubber structure.

2. The internally and externally free-rotating pin sleeve structure according to claim 1, characterized in that, The first lubrication cavity is filled with grease, and the oil storage cavity is filled with lubricating oil.

3. The internally and externally free-rotating pin sleeve structure according to claim 1, characterized in that, The inner end of the inner ring is provided with an inner conical surface.

4. The internally and externally free-rotating pin sleeve structure according to claim 1, characterized in that, The lubricating oil grooves are annular in shape and are spaced apart along the outer circumference of the inner pin sleeve.

5. The internally and externally free-rotating pin sleeve structure according to claim 1, characterized in that, The lubricating oil grooves are strip-shaped and are spaced apart along the outer circumference of the inner pin sleeve.

6. A lubricating chain, characterized in that, include: The outer link plate, the inner link plate, and the inner and outer free-rotating pin sleeve structure according to any one of claims 1 to 5, wherein the inner link plate is disposed on both sides of the outer pin sleeve, the inner link plate is provided with an interference fit mounting hole for the outer circular end of the inner pin sleeve, the outer circular end of the inner pin sleeve is located in the corresponding mounting hole, the outer link plate is disposed on the outer side of the inner link plate, the two ends of the pin shaft respectively pass through the corresponding outer link plate, the inner side of the outer link plate is recessed and provided with a second annular groove located on the outer side of the end of the inner pin sleeve, the second annular groove is provided with a thrust bushing and a first sealing element sleeved on the outer circle of the thrust bushing, the inner side of the inner link plate is recessed and provided with a third annular groove located on the outer side of the end of the outer pin sleeve, the third annular groove is provided with a second sealing element.

7. The lubricating chain according to claim 6, characterized in that, The first sealing element is a combined sealing ring, and the second sealing element is a stacked disc spring.

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