Identifying and Preventing Common Trunnion Roller Issues

Trunnion rollers, also known as trunnion wheels, are important parts of rotary drums. These components provide support to the drum and smooth rotation, making them indispensable in many industrial processes. But like any mechanical component, trunnion rollers can experience issues over time, potentially leading to costly downtime and maintenance expenses.

Wear or Damage to the Trunnion Face

One of the most frequent issues with trunnion rollers is wear or damage to the face of the wheel. While this may seem like a superficial problem at first glance, it can have significant consequences for the overall operation of the rotary drum.

When the trunnion face becomes worn or damaged, it alters the base conditions of the drum’s support system. This change can exacerbate any existing misalignment issues and increase stress on all components of the rotary drum assembly. Over time, this can lead to more severe problems and potentially cause premature failure of other parts.

Several factors can contribute to trunnion face wear, including:

• Rotary drum misalignment
• Presence of fugitive material or foreign objects in the pinch point between the tire and trunnion
• Inadequate or improper lubrication
• Excessive wheel skewing

To identify trunnion face wear, regular visual inspections should be conducted as part of a comprehensive preventative maintenance program. Look for signs of damage such as cracks, pitting, spalling, or timing marks on the trunnion surface.

When addressing trunnion face wear, plant managers have two main options:

• Trunnion roller grinding: This process involves resurfacing the worn trunnion using specialized grinding equipment to restore a like-new surface.
• Trunnion roller replacement: In cases of severe wear or when grinding is no longer feasible, replacing the entire trunnion roller may be necessary.

Inadequate Trunnion Roller Diameter

Another common issue that can arise with trunnion rollers is an inadequate diameter. This problem often develops gradually over time and can have significant impacts on the rotary drum’s performance.

When the trunnion roller diameter becomes too small, it can cause the drum to become misaligned and alter its slope. This change in geometry can affect the material retention time within the drum, potentially resulting in off-spec product and reduced efficiency.

The primary cause of inadequate trunnion roller diameter is excessive grinding or multiple grinding operations over an extended period. While each individual grinding operation may only remove a small amount of material, the cumulative effect can eventually reduce the trunnion diameter to a point where it no longer maintains the intended drum slope.

Identifying an inadequate trunnion roller diameter may require the expertise of a qualified rotary drum service provider. However, plant operators should be trained to recognize potential signs, which may include:

• Unexplained changes in material retention time or product characteristics
• Increased thrust load on bearings
• Unusually hot bearings due to the increased thrust load

When a trunnion roller’s diameter has been reduced beyond an acceptable level, the only solution is replacement. As a general rule, trunnion rollers should be replaced when they have lost approximately 10% of their original diameter to prevent adverse effects on other drum components or process parameters.

Excessive Skewing of Trunnion Roller Bearings

Trunnion roller bearings are typically skewed to maintain proper rotary drum float, which refers to the drum’s position between thrust rollers. These thrust rollers prevent the drum from drifting along its longitudinal axis. However, excessive skewing of the bearings can lead to a host of problems if left unchecked.

Excessive skewing often occurs accidentally during maintenance procedures. Because the full effects of skewing adjustments can take up to a day to manifest, operators may inadvertently over-skew the bearings in an attempt to see immediate results.

Signs of excessive skewing may include:

• The drum riding too hard in one direction (either uphill or downhill)
• Hot bearings
• Unusual wear patterns or damage on tires and/or trunnions

Resolving excessive skewing involves carefully readjusting the trunnion bearings until the drum achieves proper float and the trunnions are no longer overly skewed. This process requires precision and patience, as over-skewing, under-skewing, or skewing in the wrong direction can cause extensive damage to the equipment.

The Importance of Regular Inspections and Maintenance

Given the complex nature of rotary drum systems and the interrelated causes of many trunnion roller issues, regular inspections and proactive maintenance are crucial for preventing costly downtime and extending equipment life.

At a minimum, plant managers should schedule annual rotary drum inspections with a qualified service provider. These inspections can help catch potential problems early, before they have a chance to escalate into more serious issues.

For facilities with multiple drums, implementing a monthly dynamic inspection program can be highly beneficial. This approach involves systematically inspecting one drum thoroughly each month while visually inspecting the others that remain in operation.

Lubrication in Trunnion Roller Performance

Proper lubrication is a critical yet often overlooked aspect of trunnion roller maintenance. Adequate lubrication not only ensures smooth operation but also plays a vital role in preventing many of the common issues we’ve discussed earlier. Let’s delve into the importance of lubrication and best practices for maintaining optimal trunnion roller performance.

Trunnion rollers operate under significant loads and speeds, which can generate substantial heat and wear. A well-designed lubrication system helps to:

• Reduce friction between moving parts
• Dissipate heat generated during operation
• Prevent corrosion and rust formation
• Seal out contaminants that could damage the roller surface

Contact Kiln Technology Company Company for Trunnion Roller Support and Maintenance

When it comes to maintaining and optimizing your rotary drum equipment, partnering with a trusted expert in the field is absolutely necessary. Kiln Technology Company Company specializes in trunnion roller solutions, maintenance, and support, and offers a range of services to keep your equipment running at peak performance. Contact us to learn more about our services for trunnion rollers and rotary kilns.