Measuring wheels: linear position and speed sensing with rotary encoders

Posital measuring wheel accessories for its IXARC line of rotary encoders are said to enable the devices to make accurate linear motions and position measurements.

For conveyer belt systems, wheel-equipped encoders can provide precise speed and position controls that can be used to synchronize the motion of multiple conveyers in complex material handling systems, the company says. Since the wheel-encoder assemblies make measurements directly from the moving surface, they improve accuracy by eliminating errors due to gear backlash or hysteresis.

For cut-to-length applications, wheel/encoder assemblies can measure position directly from the surface of solid materials such as fabric, paper, wire, or sheet metal. In this operation, accuracy will improve productivity by reducing scrap losses.

Measuring wheels are available in different sizes, with circumferences of 200 mm, 500 mm, or 12 inches.

Four rim treatments are available: knurled aluminum, smooth polyurethane, and two tread patterns for the polyurethane tire.

The company has also introduced a new spring-loaded pivot arm mounting system for wheel-encoder assemblies.

Like earlier spring-loaded mounting brackets, this device is designed to minimize slippage by maintaining a steady contact pressure between the wheel and the moving surface. However, the pivot arm can accommodate larger lateral movements of the moving surface.

Spring tension can be adjusted for optimal contact pressure between the wheel and the moving surface. In addition, the position of the arm on the spring hub can be reversed, enabling the installer to change the direction of the spring load.

Posital products are available in Canada through Electromate.