What are the applications of cross roller bearings in the robotics industry?

Cross‑roller bearings feature compact structure, high rigidity, high rotational accuracy, and capacity to bear radial, axial and overturning moments. They are widely used in joints and rotary parts of industrial robots, collaborative robots and SCARA robots.

1. Base / Waist Rotary Joint

Application: 360° rotation of the robot body relative to the base.

Requirements:

• High load‑bearing capacity to withstand overall overturning moment
• Ultra‑high rigidity to avoid shaking and vibration
• High rotational precision and positioning accuracy
• Stable low‑speed operation without jitter
• Dustproof and oil‑resistant sealing performance

2. Shoulder & Upper Arm Joint

Application: Swing and rotation of the upper arm.

Requirements:

• Bear relatively large overturning moments
• High rigidity for stable start‑stop operation
• Compact size and lightweight design
• Low friction for servo‑motor driving

3. Elbow & Forearm Joint

Application: Bending and rotation of the forearm.

Requirements:

• Medium‑load capacity cross roller bearing with high precision
• Slim and compact structure for space saving
• Smooth rotation with minimal clearance

4. Wrist Joint (Most Widely Used)

Application: Posture adjustment of robot end effector via 2‑axis or 3‑axis rotation.

Requirements:

• Ultra‑thin, compact and lightweight
• High precision and zero‑clearance preload structure cross roller bearing
• Bear combined radial, axial and overturning loads
• Low noise and low friction for frequent high‑speed swing
• Impact resistance under frequent start‑stop cycles

5. End Effector Rotary Part

Application: Rotation of grippers, suction cups and tool heads.

Requirements:

• Small‑size precision cross‑roller bearings
• High repeat positioning accuracy
• Dustproof and rustproof for clean‑room working environments

6. SCARA Robot & Positioner Rotary Axis

Application: Z‑axis rotation of SCARA robots and rotary index tables.

Requirements:

• Large diameter and high rigidity
• High precision at low speed and strong eccentric load resistance

General Requirements for Robot‑Used Cross‑Roller Bearings

• Preloaded zero‑clearance structure for guaranteed precision
• Precision grade: P4 / P2
• Material: GCr15 bearing steel, quenched and tempered for wear resistance
• Long‑life grease lubrication, maintenance‑free
• Double‑sided dust‑proof seals for workshop environment