In today’s industrial landscape, cranes have emerged as an indispensable hoisting equipment in numerous fields. Their role is crucial in various applications, ranging from construction sites to manufacturing plants and warehouses. However, with their widespread use, ensuring the safety ofcranes becomes of paramount importance. One of the significant concerns that can pose a serious threat tocraneoperations is the phenomenon of rail gnawing.
Once acraneexperiences rail gnawing, the consequences can be extremely harmful. Rail gnawing can lead to a series of problems that can ultimately result in seriouscraneaccidents. These accidents not only endanger the lives and safety of operators and workers in the vicinity but also can cause extensive damage to property and disrupt operations, leading to significant economic losses.
The reasons for rail gnawing are complex and multifaceted. Construction technical parameters errors such as the coincidence degree, inclination, and gauge of thecrane‘s large vehicle tracks can all contribute to the occurrence of rail gnawing. For instance, if the tracks are not properly aligned or if there is an incorrect inclination, the wheels of thecranemay not run smoothly along the tracks, resulting in excessive friction and eventually leading to rail gnawing. Similarly, if the gauge of the tracks is not maintained within the specified range, it can also cause the wheels to deviate from their intended path and cause damage to the tracks.
However, traditional inspection methods for detecting and preventing rail gnawing have significant limitations. These methods often rely on visual inspections or simple measurements, which may not be able to detect subtle changes in the tracks or thecrane‘s operation that can lead to rail gnawing. Moreover, once rail gnawing has occurred, it can be difficult to take preventive measures using traditional methods as the damage may have already progressed to a significant extent.
Anti-rail gnawing technology:
In response to the challenges posed by rail gnawing, anti-rail gnawing technology has been widely adopted. This technology for gantrycranes offers a potential solution to mitigate the problem. However, it should be noted that this technology can only be adjusted by electrical methods and cannot completely eliminate rail gnawing. Instead, it can only adjust thecrane‘s operation within a small range repeatedly. This means that the effectiveness of this technology may not be immediate but becomes more apparent over time as the adjustments are made continuously.
For example, the electrical adjustment system can monitor the position and movement of thecranewheels in real time. If it detects any deviation from the normal path, it can send signals to adjust the speed or direction of the wheels to minimize the friction and prevent further damage to the tracks. Although this may not completely eliminate rail gnawing, it can significantly reduce the occurrence and severity of the problem.
The use of anti-rail gnawing technology can bring several benefits. Firstly, it can effectively reduce the consumption costs of large vehicle wheels, couplings, reducers, motors, and other equipment. By minimizing the friction and wear caused by rail gnawing, these components can have a longer lifespan, reducing the need for frequent replacements and repairs. Secondly, it can alleviate the contradiction of transporting billets in the finished product span. In some industrial processes, the smooth operation ofcranes is crucial for the efficient transportation of materials. Rail gnawing can disrupt this process, but anti-rail gnawing technology can help ensure that thecranecan perform its tasks without interruption. Thirdly, it can reduce a lot of manual repair costs. Manual repairs of rail gnawing can be labor-intensive and time-consuming, but with the use of this technology, the need for such repairs can be minimized. Finally, it effectively reduces the labor intensity of employees. By reducing the occurrence of rail gnawing and the need for manual repairs, employees can focus on other important tasks, improving overall work efficiency.
Not only that, but anti-rail gnawing technology also plays a crucial role in preventing the deformation of the vehicle body, protecting the vehicle body, tracks, and roof beams, and ensuring the safe operation of thecrane. By maintaining the proper alignment and movement of thecranewheels, this technology can prevent excessive stress and damage to thecrane‘s structure, ensuring its stability and reliability.
Increasing design stiffness:
Another approach to preventing rail gnawing is by appropriately increasing the stiffness of thecrane‘s design, especially the horizontal stiffness. A stiffer design can help resist the forces that can cause rail gnawing and ensure that the crane operates smoothly along the tracks.
For example, the main girder of thecraneusually adopts a box girder design. This design offers excellent horizontal stiffness and torsional stiffness, which can help distribute the load evenly and prevent excessive deflection or deformation. The box girder’s closed structure provides a high level of strength and stability, reducing the likelihood of rail gnawing.
The horizontal walkways on both ends of thecranecan also play an auxiliary role in increasing the horizontal stiffness of the bridge frame. These walkways not only provide access for maintenance and inspection but also add to the overall rigidity of the structure. By strengthening the connection between the main girder and the end girder, they help resist the lateral forces that can cause rail gnawing.
Strengthening the diaphragms of the offset box girder and making it a transverse structure design is another effective measure. The diaphragms help distribute the load and prevent local buckling or deformation. By making the box girder a transverse structure, the stiffness in the horizontal direction is enhanced, reducing the risk of rail gnawing.
Rigidly connecting the main girder and the end girder in the horizontal plane to form a rigid frame design is also beneficial. This connection provides additional stability and resistance to lateral forces, ensuring that thecraneremains in proper alignment with the tracks.
Ensuring proper free deflection:
Since the ratio of the restraint span to the base distance of thecraneis inversely proportional to the allowable free deflection of the crane, understanding and controlling this relationship is crucial for preventing rail gnawing. By ensuring that the crane has a certain free torsional swing, it can adapt to minor variations in the tracks and reduce the stress on the wheels and tracks.
When thecraneexceeds the allowable free deflection, the metal structure of thecranecan redistribute the working resistance at both ends of the working mechanism. This redistribution helps to make the speeds at both ends tend to be the same and achieve synchronization. By maintaining a balanced operation, thecranecan run more smoothly along the tracks and reduce the likelihood of rail gnawing.
For instance, if one end of thecraneexperiences more resistance due to an uneven track or some other factor, the metal structure can transfer some of the load to the other end, ensuring that both ends move at a similar speed. This self-adjusting mechanism can help prevent excessive stress on one side and reduce the risk of rail gnawing.
In conclusion, preventingcranerail gnawing is a complex task that requires a combination of measures. Anti-rail gnawing technology can provide electrical adjustments to minimize the problem, while increasing the design stiffness and ensuring proper free deflection can enhance the structural stability and operation of thecrane. By implementing these measures, craneoperators and manufacturers can reduce the occurrence of rail gnawing, ensure the safety of operations, and prolong the lifespan of cranes and their components.
