Motion System Design

Actuator saves space in sorting application

Manufacturing and packaging facilities may move and sort tons of bulk on conveyors, but the sorters, diverters, and pull-offs that route products to their next destination must be as trim as possible to make the most of valuable floor space. Engineers at Hytrol Conveyor Co., Jonesboro, Ark., needed such a space-saving solution when designing a diverter for an overhead pull-off system to divert 150-lb boxes to a different conveyor line. For help with this task, they turned to Tolomatic, Hamel, Minn., a manufacturer of rodless-style actuators.

“Our conveyors move products down the line, divert them to the next station in the manufacturing process or, if a product is defective, divert them to a reject line,” says Jackie Smith, application engineer at Hytrol. “When we needed to design a more compact diverter that could simply integrate into our systems, we decided that we needed to employ a different type of actuator.”

The traditional actuator used to operate diverters on a conveyor system is a pneumatic rod cylinder. Normally, a rod cylinder with up to a 48-in. stroke is mounted off to the side, perpendicular to the conveyor, and operates a paddle that pushes product off the conveyor or diverts it to a different line. However, these rod-style diverters consume a lot of space because the cylinder extends about 48 in. beyond the conveyor’s width. When floor space is at a premium, Hytrol offers a framed overhead diverter design that uses a BC2 rodless pneumatic actuator. The actuator’s length is the same as the conveyor’s width, and the carriage moves entirely within the actuator length.

A rodless band cylinder actuator contains its stroke within the length of the cylinder itself. For example, a 2-in. bore rodless band cylinder with a 48-in. stroke can provide 43% more space savings compared to an equivalently sized rod cylinder. In addition, a rodless actuator guides and supports the load throughout the entire stroke length, so there is minimal bearing wear and load deflection compared to rod-style cylinders. As a result, bending moments are better controlled, resulting in longer wear without seal or bearing stress.

Hytrol initially considered other types of actuators, but liked the size and performance of the rodless style and found it easy to mount within its pull-off design: It is designed with fewer carriage bolts and an adaptive mounting system. Rodless band cylinders also feature equal piston areas in both directions, eliminating load variations. Plus, the load and piston have a floating connection, resulting in less friction and longer seal life.

Depending on the application, Hytrol uses BC2 actuators with 1.5, 2.0, or 2.5-in. bores. The 2.5-in. BC2 actuator can exert forces of up to 800 lb and withstand bending moments of up to 1,800 lb, depending on carrier selection. For more information, visit Tolomatic.

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.