Double Roll Crusher Wear Parts

Roll shells are the cylindrical working surfaces mounted on the two roll shafts of a double roll crusher, and they form the gap that sizes the product. Where the feed has to be gripped or the product controlled, the shell carries teeth and is supplied as a toothed roll.

Measure the roll diameter and inspect the surface. As a plain shell wears, the gap widens and the product gets coarser; on a toothed shell the teeth round off, grip is lost and the rolls start slipping on the feed. Both are checked against the working range given for the roll assembly.

Not usually. On a two-stage machine the roll carrying the smaller teeth does the finer work and sees the most wear, so the rolls are rarely replaced on the same interval. Wear is recorded on each roll separately so replacements can be planned.

Depending on the design and how much material is left, a worn tooth profile can sometimes be rebuilt rather than replaced. The decision follows the condition of the shell and its core, so the details to send are photographs, the roll diameter and the tooth pitch.

Outer diameter, bore diameter, face width, the keyway or fixing arrangement, the tooth pattern and pitch where the shell is toothed, and the material or hardness required. A roll assembly drawing or the existing part number is the quickest way to confirm all of them.

Bearings, seals and the drive train are also wearing items, and the roll gap setting affects how fast the shells wear. Wear parts are usually reviewed together at the roll inspection so that the machine is not opened twice for the same job.