When Should Roller Mill Gears Be Replaced? 6 Signs of Wear

In a roller mill the two rolls turn at different speeds, and that speed differential is created by the roller mill gears. As the gears wear, the ratio is no longer held precisely, vibration increases and grinding quality drops without anyone noticing. That is why gears should be checked regularly rather than run until they fail.

6 signs of wear

• Change in sound: A hum, knock or rattle that is not heard in normal operation is usually the first sign of wear on the tooth flanks.
• Vibration: Increasing vibration on the mill frame or the pulley side can indicate that backlash between the teeth has grown.
• Visible marks on the teeth: Shiny bands on the flanks, pitting, burrs or thinning tooth tips.
• Broken or cracked tooth: Even one broken tooth damages the mating gear; stop the mill without delay.
• Heat: A gear guard running hotter than usual points to poor lubrication or misalignment.
• Fluctuating grinding results: Different extraction or changes in the bran at the same setting may mean the speed ratio is no longer correct.

Why do gears wear?

The most common causes are insufficient or dirty lubrication, misalignment between gear axes, sudden load changes from roll adjustment, and flour dust mixing with oil to form an abrasive paste. Regular cleaning and correct lubrication noticeably extend gear life.

What to watch when replacing

• Replace mating gears as a set wherever possible. Running a new gear against a worn partner makes the new part wear quickly too.
• Make sure the tooth count and module match the old gear; break and smooth rolls use different speed ratios.
• Check alignment after fitting and listen to the sound on the first run.
• Keep a spare gear in stock to shorten downtime.

Since 1991 Altınbaşak has been manufacturing break and smooth roll gears and pulley sets. Just send us your mill model or the tooth count of the old gear, and we will ship the right gear quickly from stock.