Product Information

Roller conveyors Functions/Applications


Choosing a roller conveyor

① Checking the products to be transported and the work environment

When choosing a roller conveyor, the first step is to conduct a detailed review of the following conditions, which will determine the appropriate model:

① Product conditions

  • Outer dimensions (length, width, height) and direction of flow
  • Weight per item (if multiple types, maximum and minimum)
  • Shape and construction of products (cardboard cases, plastic boxes, wooden crates, etc.)
  • Condition of bottom surface (exercising caution with regard to cans and plastic cases)

② Transport volume conditions

  • Will the conveyor be filled with products, or will there be spacing between products?

③ Work conditions

  • Room temperature, high temperature, or low temperature?
  • Moisture and humidity

④ Loading conditions

  • How will products be placed on the conveyor?

How to interpret transported product width

The width (W) of a given product to be transported varies with its direction of movement. When checking the direction of transport, be sure to draw a simple diagram and clearly note the direction of transport with an arrow.

② Choosing the roller width

First, choose the roller width based on the outer dimensions of the products being transported.

① Choose the roller width (W) by adding at least 50 mm to the width of the bottom surface of the products being transported.

② If there are curved sections, the roller width will vary with the width and length of the products being transported. See below when choosing the roller width.

③ Products whose bottom surface is wider than the roller width can be transported as long as their bottom surface is flat and free of any sag or other distortion. (This is known as overhanging transport). However, the bottom surface of the products being transported must not come into contact with the conveyor frame. The roller width should be between 70% and 80% of the width of the bottom surface of the products being transported.

Conveying the pallets

Use mult: Conveyors with considering of pallt strength or loaded pallet or empty pallet

③ Choosing the conveyor model

The impact load on the rollers varies with the work method associated with the loading conditions.
Choose a roller type that can withstand the impact by plugging the correct values into the following equations and referring to the chart of strength per roller:
Strength per roller ≥ Max. product weight × impact multiplier (N)

Low impact

Transport only

④ Choosing the roller pitch

Choose the roller pitch so that the bottom surface of the products being transported is always supported by at least three or four rollers. Exercise care to ensure that the load on any given roller does not exceed the allowable load.

⑤ Choosing the frame and leg pitch

On linear sections, there should be one leg every 1,500 to 2,000 mm. On curves of 45˚ or greater, there should be one leg in the middle of the section. For a more detailed indication of leg spacing, convert the product weight per meter using the chart to the right indicating the strength per two frame sections and choose a leg pitch so that the allowable load is not exceeded.

Strength table for frame pairs

⑥ Choosing the slope (angle of incline)

The slope varies with factors such as the state of the bottom surface of the products being transported and their construction and weight. The chart to the under provides general guidance.

Roller conveyor common specifications

Rollers (standalone)

Since the PS, LS, SRS, and NTS models use the same greased bearings as driven models, they have somewhat higher rolling resistance values.

Rubber Lining specifications

Lining typePrecautions
Natural rubber (NR) General-purpose use Not suitable for use with oil.
Urethane rubber (U) Wear-resistant Not suitable for use with heat.
Nitrile rubber (NBR) Oil-resistant Not suitable for use with benzene or toluene.
Neoprene rubber (CR) Heat and chemical resistant Not suitable for use with ethyl acetate.

Paint colors

RoHS compliance

Okura gravity conveyors comply with the RoHS Directive.

Okura has led the industry in working to comply with the RoHS Directive. Use of designated toxic substances has been eliminated, from the powder-coated frame to rollers and bolts. Now these conveyors are even more environmentally friendly.

RoHS Directive

The European Union (EU) adopted the RoHS Directive in July 2006 to restrict use of special toxic substances. It prohibits use of certain designated toxic substances in electric and electronic equipment by targeting the following six substances:

  • Lead
  • Cadmium
  • Hexavalent chrome
  • Mercury
  • Polybrominated biphenyl
  • Polybrominated diphenyl ether

Note: Parts other than the conveyor itself, for example legs and guides, and components finished in customer-specified colors are non-compliant. Please contact Okura if you require a RoHS-compliant solution.