Because conveyors are widely used throughout almost all industries, and because they require varying degrees of control, conveyors are a very common application for rotary encoders. Often, the encoder is applied to a motor and provides speed and direction feedback to the drive. In other instances, the encoder is applied to another shaft, such as the head-roll, either directly or via a belt. Finally, feedback can also be obtained by applying an encoder with a measuring wheel that rides on the conveyor belt; however, some segmented conveyor systems may not be suitable for measuring wheels.
Mechanically, both shaft and thru-bore encoders are good candidates for conveying applications. The encoder can be applied to the drive motor used to advance material, to a head-roll shaft, to a pinch-roller or to a lead screw. Additionally, an encoder and measuring wheel assembly can obtain feedback directly from the material itself or from a conveyor surface. An integrated solution, such as EPC's TR1 TruTracTM, simplifies encoder installation and adjustment for conveyor applications.
Electrically, variables such as resolution, output type, channels, voltage, etc., should all be specified to meet the individual application requirements. If the conveyor regularly stops, indexes or changes direction in the course of operation, a quadrature encoder is required. In the vast majority of installations, incremental encoders are most suitable.
Environmentally, proximity of the encoder to potential exposure to liquids, fine particulates and extreme temperatures will dictate specification. In filling applications with washdown requirements, an IP66 or IP67 seal can offer protection against moisture ingress. However, consider a stainless steel or polymer composite housing to mitigate the effects of harsh cleaning chemicals and solvents.