Crossed Roller Bearing

Crossed Roller Bearings offer the benefits of two-row linear bearings in a single-row space. They provide stability, low deformation and stiffness, allowing for consistently precise motion.

They can support axial forces from both directions and radial loads as well as tilting moment loads. They also require half the width of recirculating ball bearings and are very rigid.

Mechanics

Crossed rollers replace recirculating ball bearings in linear-motion devices, and they provide an extremely smooth motion with minimal vibration. They also don’t move around, which could cause friction or wear on the system. This can help to reduce maintenance costs and machine downtime.

This study investigates the mechanical characteristics of crossed roller bearings with respect to geometry and external loads using a five degree-of-freedom model. It also takes the inner and outer raceway roundness error into account. The results show that the rotational accuracy and load distribution of CRBs depend on their geometry.

If you need a compact solution, our CRBS and CRBC series are available in a split inner ring with integrated outer ring type. This offers high rigidity in a small package and is ideal for applications that require rotating the inner ring. If you need extra capacity for dynamic short-stroke applications, consider our RSDE with ACC technology. This provides the highest level of running accuracy and rigidity in a compact size.

Design

The crossed roller bearing replaces recirculating ball bearings in linear actuators that require a large footprint. Its design eliminates the friction and noise created by the ball bearing’s shuttling motion and delivers high rigidity and accuracy.

The axial contact of crossed rollers prevents contact between adjacent rails and allows the bearing to withstand high overturning moments. It also carries radial and axial loads in both directions, tilting moment loads and combinations of these.

Crossed roller bearings have a two-part structure and can be used in applications with restricted space or in which contamination is unacceptable. They can be fitted with metal or plastic cages, and can be made to a variety of tolerances. It’s possible to adjust the load capacity by increasing the distance between the rollers, though this will reduce their rotational precision. Crowned races would make this easier, but they’re difficult to fabricate with the necessary precision. A better option is a split inner and outer ring.

Application

Crossed Roller Bearings replace recirculating ball bearings to reduce noise, vibration and wear. They are compact and can handle radial, thrust and moment loads simultaneously. They also have high rotational accuracy. This makes them a popular choice in linear actuators, industrial robots and medical equipment.

When selecting a crossed roller bearing, consider your application. Do you need to move heavy or delicate loads? Will the bearing be mounted on an uneven surface? Crossed rollers offer larger contact surfaces than recirculating ball bearings, and this improves performance in applications that require greater rigidity.

The cage (or retainer) that holds the rollers in place is another important consideration. Traditional metal cages use tabs that fit into notches on the top and bottom of each roller. PM offers these cages in both plain and stainless steel. Stainless steel is a better choice for use in cleanrooms and vacuum applications, where plastic can out-gas and degrade sensitive environments. It is also a good option for washdown and medical applications where rust is unacceptable.

Maintenance

HIWIN Crossed Roller Bearings are used in a wide variety of applications including medical and lab equipment, machine tools, semiconductor processing, clean rooms and vacuum environments, material handling, vision inspection, robotics, and automation machinery. They have a very high rigidity and running accuracy with excellent load capacity, and they can support axial loads in both directions as well as radial and tilting moment loads.

Compared to recirculating ball bushings, these bearings are much more compact. Depending on the model and size of the stage, they can fit in spaces up to twice as long as the required travel distance of the rail assembly.

Like all linear stages, they require routine cleaning and lubrication to ensure proper operation. We recommend applying a light coating of the correct specified grease to the rail v-groove using a lint free swab. Also, it’s a good idea to run the stage through its full range of motion periodically to redistribute the grease.