Examining the modular conveyor system
14th September 2022Designing modular conveyor belts is quite complex. Engineers first examine the application to understand the customer’s requirements and conveyance objectives. Is the processor trying to convey delicate product gently, or is there a heavy, robust item to move from one operation to another? Does the application require high or low friction conveyance? Are there any special abrasive or load characteristics in the application?
Belt speeds, impact resistance, application temperature, required belt life, and other special considerations also play a critical role in the initial design.
Manufacturing uses plastic pellets injection-molded into modules to create a belt. Modular conveyors are assembled into interlocking patterns and joined by hinge rods. Depending on the style, a typical 2-ft 3 50-ft belt uses 600—4000 modules.
Positive drives increase efficiency and maximize torque transmitting capabilities, while the belts are driven by plastic or metal sprockets instead of friction rollers. Sprockets have square bores and are driven by matching square shafts (round bore sprockets are available for special applications).
Square shafts transmit torque without the need for troublesome keys and keyways, and accommodate the lateral expansion differences of the plastic belt material and metal shafts. Typically, only one sprocket per shaft is retained in the drive system. Other sprockets are allowed to float, moving along the shaft as the belt expands or contracts. Thus, the sprockets are always transmitting torque.
Belt materials are available in several versions, with polypropylene, polyethylene, and acetal thermoplastics being the most common.