Vibration Issues in Bomag 120 AD-3 Rollers

[MikePhua]

The Bomag 120 AD-3 is a well-known model in the world of asphalt compacting and soil compaction machinery. It is commonly used in road construction and other civil engineering projects, where effective compaction is critical for ensuring the durability and longevity of paved surfaces. However, like any heavy machinery, it can experience mechanical or operational issues. One common problem that can arise in this type of equipment is related to the vibration system, which plays a crucial role in the compaction process.
Overview of the Bomag 120 AD-3 Roller
The Bomag 120 AD-3 is a dual drum roller with a vibratory system, designed to provide high compaction efficiency. The roller’s dual drum system allows it to cover large areas in less time while ensuring consistent compaction. The vibration system is vital because it provides the dynamic force needed to compact materials such as soil, gravel, or asphalt.
Bomag, a renowned manufacturer of compaction equipment, has a long history of producing reliable machines for the construction industry. Founded in 1957 in Germany, Bomag initially specialized in paving and compaction equipment and has since expanded its product range to include a variety of machines used for asphalt paving, soil compaction, and road construction. Bomag’s focus on quality and efficiency has made it a leading brand in the global construction industry.
The Role of Vibration in the Compaction Process
Before delving into the potential causes of vibration issues, it’s important to understand the function of the vibration system. In compacting equipment like the Bomag 120 AD-3, vibration is used to create a high-frequency dynamic load that compacts the material being worked on. This process works by exerting pressure through the vibratory drums, which helps to break down the granular material and eliminate air pockets, leading to a denser, more stable surface.
The vibration system typically consists of several components, including:

• Hydraulic pumps to drive the vibration mechanism.
  
• Exciter mechanisms located inside the drums.
  
• Vibration control systems that regulate the intensity and frequency of the vibration.
  

When the vibration system is malfunctioning, it can significantly impact the performance of the machine and compromise the quality of the compaction process.
Common Vibration Issues in Bomag 120 AD-3 Rollers
Operators of Bomag 120 AD-3 rollers have reported several common vibration-related issues that can affect the machine’s operation. These issues can arise due to a variety of mechanical, electrical, or hydraulic failures. Below are the most common problems:
1. Loss of Vibration Power
One of the most noticeable issues is the loss of vibration power, where the roller’s drums fail to produce the necessary vibratory force for effective compaction. This can lead to inefficient work, especially in projects requiring high compaction levels.
Possible Causes:

• Hydraulic pump failure: The hydraulic pump responsible for powering the vibration mechanism may be malfunctioning. If the pump is not providing sufficient pressure or flow, the exciter mechanism in the drums will not operate properly.
  
• Faulty solenoid valves: The solenoid valves control the flow of hydraulic fluid to the vibration system. A malfunctioning solenoid can disrupt the operation of the vibration system.
  
• Clogged hydraulic lines: Over time, the hydraulic lines can become clogged with debris or dirt, preventing the proper flow of hydraulic fluid to the vibration components.
  

Solutions:

• Check hydraulic pump pressure to ensure it is within the manufacturer’s recommended range.
  
• Inspect and clean hydraulic lines to remove any blockages.
  
• Test and replace faulty solenoid valves if needed.
  

2. Irregular Vibration Frequency
Another common problem is irregular vibration, where the intensity or frequency of the vibration is inconsistent. This can result in uneven compaction and may cause surface defects in the material being compacted.
Possible Causes:

• Worn exciter bearings: The exciter mechanism inside the drum is responsible for generating the vibratory force. Over time, the bearings in the exciter can wear down, leading to irregular vibration patterns.
  
• Loose or damaged components: If the components in the vibration system, such as the eccentric weights or shafts, become loose or damaged, it can cause the vibration to fluctuate.
  
• Hydraulic pressure fluctuations: Inconsistent hydraulic pressure can lead to variations in vibration frequency, making it difficult to achieve uniform compaction.
  

Solutions:

• Inspect and replace exciter bearings that have excessive wear.
  
• Tighten or replace loose components in the vibration mechanism.
  
• Ensure steady hydraulic pressure by checking the pump and hydraulic fluid levels.
  

3. Vibration Failure at Low Speeds
Some operators may notice that the vibration system works fine at higher speeds but fails or performs poorly at lower speeds. This can be particularly problematic when the roller needs to make precise adjustments in smaller areas.
Possible Causes:

• Low hydraulic fluid levels: Insufficient hydraulic fluid can lead to decreased pressure, affecting the operation of the vibration system at lower speeds.
  
• Faulty flow control valve: The flow control valve regulates the hydraulic flow to the vibration system. If it malfunctions, the vibration system may not receive enough fluid at low speeds.
  
• Contaminated hydraulic fluid: Contaminants in the hydraulic fluid can cause the system to perform erratically, particularly at low speeds.
  

Solutions:

• Check hydraulic fluid levels and top up if necessary.
  
• Inspect the flow control valve and replace it if it’s malfunctioning.
  
• Change the hydraulic fluid to ensure it’s free from contaminants.
  

4. Excessive Vibration or Uncontrolled Vibration
In some cases, the machine may exhibit excessive or uncontrollable vibration, which can lead to discomfort for the operator and damage to the equipment or the material being compacted.
Possible Causes:

• Damaged or unbalanced drums: If the vibratory drums become bent or unbalanced, they can produce excessive vibration.
  
• Faulty vibration control system: The control system that regulates the intensity of vibration could be malfunctioning, causing the machine to vibrate at higher-than-normal levels.
  

Solutions:

• Inspect the vibratory drums for signs of damage or imbalance and repair or replace them as needed.
  
• Test the vibration control system and replace faulty components.
  

Preventative Maintenance and Troubleshooting Tips
To avoid frequent vibration issues and ensure the Bomag 120 AD-3 roller continues to operate smoothly, operators should implement regular maintenance and troubleshooting routines. Some key practices include:

• Regularly check hydraulic fluid levels and cleanliness to ensure optimal system performance.
  
• Inspect vibration components such as the exciter mechanism, bearings, and hydraulic lines for wear or damage.
  
• Lubricate the exciter bearings and other moving parts to prevent premature wear.
  
• Monitor machine performance during operation, looking for signs of irregular vibration, loss of power, or abnormal behavior.
  

Conclusion
The Bomag 120 AD-3 roller is a robust and reliable machine for compaction in the construction industry. However, like all machinery, it requires regular maintenance and attention to detail to prevent vibration-related issues that could hinder its performance. By understanding the potential causes of vibration problems and implementing proper diagnostic and repair techniques, operators can ensure the continued efficiency and longevity of their machines. Regular maintenance, including checking hydraulic components, exciter systems, and vibration controls, will help mitigate the risks of operational downtime and ensure that compaction projects run smoothly.