Hey everyone! As a supplier of RTG cranes, I've seen my fair share of slewing problems with these machines. RTG cranes, also known as Rubber Tyred Gantry Crane, are widely used in port terminals and container yards, and their slewing function is crucial for efficient operation. Today, I'm going to share some of the common slewing problems I've encountered and how we can deal with them.
1. Abnormal Noise during Slewing
One of the most noticeable issues is abnormal noise when the crane is slewing. This can be caused by several factors. First, it might be due to lack of lubrication in the slewing bearing. The slewing bearing is a critical component that allows the crane to rotate smoothly. When there isn't enough lubricant, the metal-to-metal contact between the bearing's components will generate excessive friction, resulting in strange noises.
Another possible cause could be damage to the gear teeth in the slewing mechanism. If the gears are worn out, misaligned, or have suffered from impact damage, they won't mesh properly. This improper meshing leads to uneven force distribution and produces noise. Sometimes, loose bolts in the slewing structure can also contribute to the noise. Vibration from the movement can cause bolts to loosen over time, and the rattling of these loose parts adds to the abnormal sound.
To fix these problems, for the lubrication issue, we need to check the lubrication level regularly and refill it as needed. Make sure to use the correct type of lubricant recommended by the manufacturer. If the gears are damaged, we may have to replace them. And for loose bolts, a simple re - tightening can usually solve the problem.
2. Slow or Stalling Slewing
A RTG crane that slews slowly or stalls during operation is a major headache for port terminal operators. Electrical problems are often the culprit behind this issue. The motor that drives the slewing mechanism might not be getting enough power. This could be due to a faulty circuit breaker, a damaged cable, or a problem with the motor controller. If the circuit breaker trips frequently, it might be overloaded, or there could be a short - circuit somewhere in the electrical system.
Mechanical problems can also cause slow or stalling slewing. For example, the slewing brake may not be releasing properly. If the brake is still applying some force when the crane is supposed to be slewing, it will create resistance and slow down the rotation. Additionally, excessive friction in the Port Terminal Travelling Mechanism due to dirt, debris, or misalignment can also impede the slewing movement.
For electrical problems, we need to inspect the entire electrical system thoroughly. Check the circuit breakers, replace any damaged cables, and test the motor controller. Regarding mechanical issues, we have to clean the slewing mechanism to remove dirt and debris. Adjust the slewing brake to ensure it releases completely, and realign any misaligned components.
3. Inaccurate Positioning during Slewing
Accurate positioning is essential for RTG cranes, especially when handling containers. However, sometimes the crane may not stop at the exact position as intended during slewing. This can be a result of problems with the positioning sensors. These sensors are responsible for detecting the crane's position and sending signals to the control system. If the sensors are malfunctioning, they may provide incorrect position information, leading to inaccurate stops.
Another factor could be the control system itself. If the control algorithm is not calibrated correctly, it may not be able to calculate the correct stopping point based on the crane's speed and direction. Moreover, external factors such as wind can also affect the positioning accuracy. Strong winds can push the crane during slewing, causing it to deviate from the planned path.
To solve the sensor problem, we need to test and calibrate the positioning sensors regularly. If a sensor is found to be faulty, replace it immediately. For the control system, we should update the control algorithm and ensure it is properly configured. When dealing with wind effects, in some cases, we may need to install wind - resistant devices or adjust the operation schedule to avoid working in extremely windy conditions.
4. Excessive Vibration during Slewing
Excessive vibration during slewing can not only cause discomfort to the operator but also lead to premature wear and damage of the crane components. Unbalanced loads are a common cause of this problem. If the containers or other loads are not evenly distributed on the crane's spreader, it will create an uneven center of gravity. As the crane slews, this imbalance will cause the crane to vibrate.
The foundation on which the RTG crane is operating can also be a factor. If the ground is uneven or soft, the crane may experience instability during slewing, resulting in vibrations. Additionally, problems with the slewing drive system, such as a worn - out coupling or a malfunctioning hydraulic pump (if it's a hydraulic - driven slewing system), can cause vibrations.
To address the load imbalance issue, we should ensure that the loads are properly arranged and secured on the spreader before operation. For the foundation problem, we may need to reinforce the ground or relocate the crane to a more stable area. Regarding the drive system, inspect and replace any worn - out or faulty components.
Why Choose Our RTG Cranes
At our company, we understand these common slewing problems and have taken numerous measures to prevent them in our RTG cranes. We use high - quality components for the slewing mechanism, including durable slewing bearings and precisely manufactured gears. Our electrical systems are rigorously tested to ensure stable power supply to the slewing motor.
We also provide in - depth training for the operators on how to properly use and maintain the cranes, which can help reduce the occurrence of many of these problems. Moreover, we offer excellent after - sales service. If you encounter any slewing or other problems with our RTG cranes, our professional technicians will be on - site as soon as possible to provide solutions.
If you're in the market for a reliable RTG crane, don't hesitate to contact us for more information and procurement discussions. We look forward to helping you find the perfect RTG crane solution for your port terminal or container yard.
References
- Crane Industry Handbook
- Port Terminal Equipment Maintenance Guide
