Crossed Roller Thrust Bearings 

Timken's crossed roller bearings (TXRs) are designed to offer the highest levels of rotation accuracy and rigidity while conserving space and saving material costs. Able to withstand high overturning moments, TXR bearings are ideal for the table bearing of machine tools, including vertical boring and grinding machines. They also are uniquely suited to many pivot and pedestal applications where space is limited or the lowest possible center of gravity of a rotating mass is required.

Size ranges:  457.2 mm - 1549.4 mm (8 in. to 61 in.)

Design Attributes 

• TXRs feature two rows of rollers in the space of one and its cross section occupies little space, resulting in less housing material, reduced machining requirements and reduced cost.
• Line contact on the roller raceway and roller configuration provide maximum accuracy of rotation, high stability and greater tilting stiffness.
• Adjustable design for optimum preload lengthens bearing life, maximizes rigidity and provides for minimum runout.
• Design allows for lubricants and contaminants to be easily purged.
• Nylon separators provide low inertia and low running torque.
• Components are made from case-carburized steel, which provides a tough, shock-resistant core and hard surfaces.

Applications

• Precision rotary and indexing tables for machine tools
• Vertical and horizontal boring mills
• Vertical grinding machines
• Rotary surface grinding machines
• Large gear hobbing machines
• Gun and radar turrets
• Large radio and optical telescopes
• Swiveling cameras
• Steering pivots and casters
• Pivots where height is restricted
• Microscope tables
• Cane center pivots
• Swiveling bogies
• Welding manipulators
• Large tanker mooring buoys
• Rotary assembly jigs
• Industrial robots

The TXR crossed roller bearing features two sets of races and rollers together at right angles, with alternate rollers facing opposite directions. To save space and require less housing material, the bearing’s cross section height barely exceeds that of a single-row bearing. Its steep-angle, tapered geometry results in a total effective bearing spread many times greater than the width of the bearing itself.

The most common configuration is type TXRDO, which features a double outer race and two inner rings, with rollers spaced by nylon separators. Other configurations to fit specific application needs are available as well.