What a smooth roll gear does
Semolina and middlings from the break passages are reduced to flour on smooth (plain-surface) rolls. The goal here is not to cut but to grind finer by pressure, so a lower speed differential is needed than on the break passages. The part that creates this differential is the smooth roll gear.
How the ratio is set
The speed ratio is the ratio of the tooth counts of the two mating gears. For example, the Z-40 and Z-33 pair used in our smooth roll sets gives a ratio of about 1.2. If the ratio is too high, flour can overheat and starch damage may rise; if too low, reduction efficiency drops. The tooth count must therefore be kept when replacing.
Why wear goes unnoticed on smooth roll gears
Load on smooth passages is more even than on break passages, so the gears run trouble-free for a long time and wear is noticed late. During routine checks look for:
- Shiny wear bands and burrs on the tooth flanks,
- Growing backlash and the knocking noise that comes with it,
- Unexpected heat at the roll bearings or gear guard,
- Fluctuating flour fineness and sifter loads.
Installation and maintenance
Clean the shaft and keyway before fitting and make sure the key seats fully. Replacing the gear pair together protects the life of the new gear. Remove flour dust from the guard periodically and lubricate with a suitable lubricant.
Altınbaşak smooth roll gears
Our smooth roll gears are marked with tooth count and bore (e.g. Z-40 D-70), which lets us find the right part quickly when you order. We ship stocked gears fast and manufacture to suit your mill when needed.







