Plain Bearing Hollow-Core Rollers Reduce Weight in Cargo Planes

Related Vendors

igus GmbH

FAULHABER Drive Systems

SIMTOS (Seoul International Machine Tool Show)

Every gram saved counts in aviation. New FAA-compliant ball bearings for conveyor systems in cargo aircraft are designed to reduce weight while combining high load-bearing capacity with permanently lubrication-free operation.

Igus has developed new ball rollers from the Xiros product line for cargo handling systems in cargo aircraft. The rollers are certified for use in aviation and meet the U.S. Federal Aviation Administration (FAA)’s fire safety requirements for aircraft interiors. Their hollow stainless-steel balls weigh up to 49 percent less than equivalent solid balls. Since several hundred ball rollers are installed in a cargo aircraft, the weight savings can have an impact on the total weight and, consequently, on fuel consumption.

Design and Weight Reduction

Ball rollers are recessed into the floor of cargo aircraft. They form a conveyor surface on which containers can be moved in two directions. The new rollers consist of a housing made of the high-performance plastic Iglidur J350 and a hollow stainless-steel ball that moves within the housing.

The ball bearings are available in three sizes with ball diameters of 22 (0.866 inches), 25.4 (1 inch), and 30 millimeters. For a ball with a diameter of 25.4 millimeters (1.181 inches), the weight of the solid stainless steel version is 87 grams. The hollow version weighs 43 grams (1.52 ounces). With 500 ball rollers, this results in a weight reduction of approximately 22 kilograms (48.5 pounds) per aircraft. According to Igus, this weight savings can help reduce fuel consumption, increase range, or boost available payload. The actual effect depends on the specific aircraft and its operational profile.

High Load Capacity Despite Low Weight

“Design engineers don’t have to worry about any reduction in load-carrying capacity when making the switch,” emphasizes Marcus Semsroth, head of the Xiros polymer ball bearing division at Igus.

The permissible static pressure load is 1,470 newtons (331 pounds-force). This corresponds to a load of approximately 150 kilograms (331 pounds) that can be applied to a single ball bearing. Tests conducted in the company’s own 5,500-square-meter (59,200-square-foot) test laboratory also showed that the ball bearings can support loads up to four times that amount.

Lubrication-Free Operation

Many conventional ball bearings require regular lubrication. However, lubricants can attract dust and dirt, which reduces smoothness of operation and increases the amount of cleaning required.

The new Xiros ball rollers feature solid lubricants integrated into the plastic housing. These are released during movement, enabling low-friction dry operation without the need for external lubricants. This eliminates the need for relubrication, and the rollers are less prone to lubricant-related contamination.

“With the new Xiros ball rollers, we are demonstrating that lightweight construction, high load capacity, and lubrication-free operation can be combined,” Semsroth concludes. “These are three key advantages for modern material handling systems in the aerospace industry.” The combination of lower weight, high load-carrying capacity, and low-maintenance operation is intended to make the ball rollers suitable for material handling systems in cargo aircraft. 

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