Bearings for Robotics & Automation
Robot joints and automation modules are specified for stiffness per unit of envelope, repetition accuracy and a duty cycle measured in millions of small movements. Thin-section and crossed roller designs make the joint itself, while plain and rod-end bearings handle the linkages.
Typical duty
- Very high duty cycle with frequent starts, stops and reversals.
- Small displacements rather than full rotations at some axes.
- High stiffness demand: any play appears directly as positioning error.
- Light loads, so weight and inertia of the bearing itself matter.
- Clean, controlled environment - lubrication is chosen for life, not for contamination resistance.
Recommended types & suffixes
Type, reason and the suffix that follows from it
| Type | Why it suits the application | Suffix guidance |
|---|
| Crossed roller bearings | Robot joints and rotary tables: high stiffness and accuracy in a thin section. | Slewing-ring or thin-section format, preloaded by design. |
| Thin-section deep groove ball bearings | Weight-critical joints where a slim profile is required. | Precision class and a controlled fit matter more than extra capacity. |
| Spherical plain bearings | Linkages, grippers and cylinder mounts taking oscillating load. | Maintenance-free liners where relubrication is impossible. |
| Needle roller bearings | Compact joints and gearboxes where radial space is at a premium. | Drawn-cup or machined-ring types, hardened shaft needed for NK/RNA. |
Models for this application
From the live catalogue, 8–120 mm bore
Models are listed for reference. For a specific duty we confirm the clearance, seal and lubricant before quoting -
send the application.
Installation & maintenance notes
- Stiffness, not capacity, is usually the buying criterion: check the bearing's axial and tilting rigidity.
- Account for the duty cycle as well as the load - millions of small movements fatigue the raceway differently.
- Keep play out of the axis: even a few micrometres shows up as position error at the end effector.
- Light preload improves repeatability but raises friction and temperature; match it to the drive.
- Weigh the inertia: a lighter bearing allows faster acceleration with the same motor.
Common mistakes in this industry
- Selecting on load rating alone when the axis is stiffness-limited.
- Using a standard bearing with clearance in an axis that needs preload to hold position.
- Ignoring the duty cycle and treating small oscillating movements as if the bearing turned continuously.
Further reading
Frequently asked questions
Why are crossed roller bearings used in robot joints?
The crossed arrangement makes one bearing carry radial, axial and tilting moment loads at once, with high stiffness and a thin section - exactly what a robot joint needs in a small envelope.
Does duty cycle really matter for bearings?
Yes. Millions of small oscillating movements do not build a full lubricant film, so wear and micro-fretting dominate over classical rolling fatigue. That shifts the selection towards lubrication and surface quality.
How do I reduce play in a joint?
Use a preloaded or matched pair, control the fits so the rings do not loosen, and make sure the joint structure itself is stiff. Bearing clearance is only one source of lost motion.
Sourcing for Robotics?
Send the model number, quantity and destination - we reply within 30 minutes on working days.