STRESSES, SLIP AND ABRASION OF RUBBER COVERED CONVEYOR ROLLERS

Conveyors consist of rubber coated, fiber reinforced belts which are supported and driven by rollers. The rollers arc generally coated lo increase and stabilize the friction and to reduce abrasion, noise and dirt buildup. Pressures and shear stresses in the rubber layer depend on belt tension, driving forces, geoimetry and material properties of belt and roller. Most rollers fail due lo abrasion when the shear stresses are higher than the friction forces. Slip due lo pressure between the bell and the rubber layer is proportional to piessure. Additional slip arises from troughing transitions, uneven belts and rollers and from driving forces. Abrasion due to slip is proportional to the pressure of the belt to the power 1.5 to 3. Equations to predict stresses, slip and abrasion are presented. To reduce abrasion rates, conveyors should have large diameter rollers, low belt tension and a wide belt. Also, cylindrically machined pulleys, high quality belts and long troughing transitions should be employed.