A How To Guide for Inspecting your Replacement Wear Parts

Machines that reduce the size of a material also erode the grinding elements. In general, the more abrasive the material you grind, the more and the more quickly the hammers and other parts wear.  To ensure efficient operation and longevity of your Hammer mill, it’s crucial to regularly inspect and maintain its wear parts. These components include hammers, rods, screens, bearings, and wear plates. In this guide, we will walk you through the steps of inspecting wear parts on a hammer mill to keep it running smoothly and avoid costly downtime.

Tools and materials you’ll need

Before you begin inspecting wear parts on your hammermill, gather the following tools and materials:

• Safety glasses
• Ear protection
• Gloves
• Wrenches and socket set
• Screwdrivers
• Hammer
• Any replacement parts needed

Step 1: Visual Inspection of Hammers and Hammer Rods

The hammers (51) are critical components of a hammermill, and their wear can significantly impact performance. Each hammer has four striking edges. As each edge becomes worn, rotate the hammer to use a new edge. Do not allow the hammer to wear too much or the opposite striking edges become unusable. Look for signs of wear on the hammers. Common wear indicators include:

• Rounded edges
  • Rotate hammers when leading edge becomes rounded.
  • Replace hammers when all cutting edges are rounded.
• Blunted or chipped edges
• Cracks or fractures

Rotate the hammers if you notice any of the following issues:

• Decrease in grinding efficiency indicated by more time needed to grind the same volume of material, increased heat, or increased power usage.
• Inspection shows the hammer edge is rounded.

Follow these steps to inspect the hammers (51) and hammer rods (52):

1. Open the mill hood (43). 
2. Slide the hammer rods (52) of the row through the end of the rotor discs (49). Work on only one row of hammers at a time.
3. Turn every hammer in the row in the same way to view the striking edge.
   1. If the edge is worn, plan to rotate all hammers in the row to a new edge. 
   2. When all 4 edges are worn, plan to replace all hammers in the row and the hammer rod.
4. Inspect the hammer rods for wear, indicated by grooving on the rod.
   1. Plan to replace the hammer rod if grooving is present.
5. Go to the next row. Do not interchange hammers from one row to another.
6. Check for imbalance: Ensure the hammers are evenly distributed across the rotor (48). Imbalanced hammers can lead to vibrations and reduced efficiency.
7. Replace worn hammers: If hammers show excessive wear or damage, replace them with new ones according to your mill manual.

Step 2: Examine Screens

Your mill has either a perforated metal screen or grate on the front and rear of the mill. The screens (50) in your hammermill play a crucial role in determining particle size. Inspect them for wear and damage:

1. Remove screens (50): Use appropriate tools to remove the screens from the hammermill.
2. Check for wear: Look for signs of wear, such as holes, tears, or excessive clogging. Screens with worn-out openings can lead to inconsistent particle size.
3. Clean screens: If screens are clogged with material buildup, clean them thoroughly. A clean screen ensures better efficiency.
4. Replace damaged screens: If screens are damaged or worn beyond their usable life, replace them with new ones following the mill manual.

Step 3: Inspecting Wear Plates

Wear plates protect the mill housing. There are two on the hood (45) of the mill and one at the back of the rotor (x). When a plate becomes worn, the housing is exposed to the material. Inspect the plate regularly for signs of wear or thinning. 

1. Replace wear plates when they show signs of thinning. Earliest signs of thinning are seen around the bolts. If you find excessive wear, replace with a new plate using new bolts.

Step 4: Inspect Bearings

Properly functioning bearings (49) are essential for the hammermill’s smooth operation:

• Inspect bearings: Check for signs of wear, overheating, or vibration in the bearings. Replace any damaged or worn bearings promptly.

Step 5: Lubricate Moving Parts

Proper lubrication of bearings (49) and moving parts is vital for reducing wear and extending the lifespan of your hammermill. Refer to your manual’s guidelines for the recommended lubrication schedule and type of lubricants to use. Properly lubricating is important for reducing friction and wear on moving parts:

• Apply lubricant: Lubricate all moving parts as instructed in the manual. Pay special attention to the rotor and bearings.

Step 6: Final Checks

Before putting your hammermill back into operation, perform these final checks:

• Reassemble: Reassemble all components, ensuring that you’ve properly replaced any worn or damaged parts.
• Tighten all fasteners: Make sure all bolts, nuts, and fasteners are tightened to the recommended torque values.
• Test run: Start the hammermill and run it briefly to ensure it’s functioning correctly. Listen for unusual noises or vibrations.
• Record the inspection: Document the date of the inspection, the parts checked, and any maintenance or replacement actions taken.

Step 7: Keep A Regular Maintenance Schedule

To keep your hammermill in optimal condition, follow a regular inspection and maintenance schedule for your hammermill. This schedule should include routine inspections, lubrication, and proactive replacement of wear parts before they cause significant issues.

It is also important to maintain detailed records of your inspections, including the date, findings, and any maintenance or replacement actions taken. This documentation can help you track the condition of your hammermill over time and plan for future maintenance.

By following these steps and maintaining a proactive approach to wear part inspections and maintenance, you can ensure the continued efficiency and safety of your hammermill while minimizing downtime and costly repairs. Always consult your hammermill’s manual for specific guidelines and recommendations related to your particular machine.