Application of Precision Bearings in Industrial Robots

I. The Role of Precision Bearings in Industrial Robots

First, they support combined loads. Precision bearings handle the radial forces, axial forces, and massive overturning moments generated during robot movement, as well as the equipment's heavy loads, ensuring the structural integrity of the robot's joints against deformation.

Second, they ensure rotational accuracy and repeatability. Industrial robots impose stringent requirements on rotational and positioning accuracy, often demanding that repeatability errors be controlled within ±0.02 mm or even tighter tolerances. Precision bearings undergo high-precision grinding to strictly control roundness and dimensional errors, minimizing rotational clearance to ensure highly consistent positioning with every movement.

Third, they reduce frictional loss, extend the machine's service life, and minimize downtime for maintenance. High-quality precision bearings feature raceways finished via super-finishing processes, resulting in extremely low friction coefficients and minimal joint rotation resistance. This leads to lower servo motor energy consumption, reduced operating noise, and minimal temperature rise; furthermore, they exhibit slow wear rates during prolonged, high-frequency cyclic operation, thereby maintaining precision over a longer period.

II. What precision bearings are used in industrial robots?

2.1 Slewing Bearings

Slewing bearings (also known as slewing ring bearings) are large-diameter bearings capable of 360-degree rotation. Classified by gear type, they include internal gear, external gear, and gearless configurations. Capable of simultaneously withstanding massive axial loads, radial loads, and tilting moments, they feature a compact structure and ease of installation, making them the preferred choice for heavy-duty palletizing robots, large material-handling robots, and large automated rotary tables.

Industrial robots often require high rotational precision and the ability to support heavy loads while undergoing continuous oscillation and significant alternating tilting moments; slewing bearings effectively meet these demanding requirements.

LTZC manufactures precision slewing bearings specifically for robots, offering two mainstream configurations: four-point contact ball bearings and three-row cylindrical roller bearings. Featuring precision-ground raceways and accuracy reaching the P4 precision grade, the product range spans from small, lightweight slewing rings to large-diameter, heavy-duty bearings, fully meeting customization needs for robots of various tonnage capacities.

2.2 Crossed Roller Bearings

Crossed roller bearings are the most widely used type of precision bearing for robot joints. Their internal rolling elements are arranged in a mutually perpendicular, 90-degree crisscross pattern, providing high rigidity and load-bearing capacity. Their compact structure allows for installation in space-constrained robot designs; by reducing rotational inertia, they enable faster start-stop responses and smoother, more flexible movement.

LTZC precision crossed roller bearings achieve accuracy levels up to P2 (ultra-precision grade) and feature raceway hardness of HRC 58–62. They deliver minimal vibration and low torque fluctuation, making them ideally suited for robot joints subject to high-frequency reciprocating motion. 

2.3 Thin-Section Precision Bearings

Small industrial robots often have limited installation space, necessitating the use of thin-section precision bearings. Characterized by ultra-thin cross-sections and a lightweight design, these bearings not only reduce the equipment's overall weight but also lower the robot's energy consumption. LTZC offers custom manufacturing for various thin-section bearing configurations, including open, sealed, angular contact, and four-point contact types.

Ⅲ. LTZC Precision Robot Bearing Solutions

3.1 Introduction to LTZC Bearings

Established in 1996, the LTZC brand has dedicated over three decades to the R&D and manufacturing of high-end precision bearings, large-diameter slewing bearings, and heavy-duty/extra-heavy-duty bearings. For years, the company has consistently provided high-quality slewing bearings and solutions to sectors such as robotics, port equipment, and construction machinery. The factory is equipped with a full suite of large-scale CNC lathes and slewing bearing processing equipment, with product sizes ranging from 100mm to 15,000mm. LTZC handles both mass orders for standard robot bearings and customized development projects for small-batch, multi-variety non-standard precision robot bearings.

LTZC products are exported to numerous countries and regions worldwide—including Southeast Asia, Europe, the Middle East, Russia, India, and Vietnam—offering customers a one-stop service that spans everything from design to logistics and shipping.

3.2 LTZC Precision Bearing Manufacturing Processes

LTZC bearing forgings utilize high-end raw materials such as 42CrMo alloy steel; material specifications can be adjusted to meet unique customer requirements, and raw material inspection reports are provided for every forging. LTZC employs precise surface hardening treatments on robot bearing raceways, maintaining raceway hardness within the HRC 58–62 range while minimizing heat treatment deformation. During the finishing stage, raceways undergo grinding to reduce surface roughness to Ra ≤ 0.8μm, ensuring smooth, low-noise operation.

3.3 BV, CCS, and ISO9001 Certifications

LTZC operates its entire production process in strict accordance with the ISO9001 quality management system. Every bearing is fully traceable to its original documentation, and every precision bearing, slewing bearing, and robot bearing undergoes comprehensive final inspection for accuracy before leaving the factory.

LTZC products support third-party factory inspections by agencies such as BV and CCS, and the company provides factory inspection reports, material certificates, heat treatment reports, and more.

3.4 LTZC’s Robust Non-Standard Customization Solutions

LTZC boasts a technical team of experienced mechanical engineers dedicated to solving complex rotation-related challenges across various industries. Simply provide your slewing bearing requirements, and we will design the blueprints and offer solutions covering bearing selection, sealing systems, lubrication systems, and more.

Contact LTZC to customize precision bearing solutions for robots.

IV. FAQ on Precision Bearings for Robots

Q1: What are the most common types of precision bearings used in industrial robots?

A: They primarily include slewing bearings, crossed roller bearings, and thin-section precision bearings. Slewing bearings are the preferred choice for the bases of heavy-duty robots.

Q2: Can LTZC customize industrial robot bearings based on customer drawings?

A: Yes. LTZC specializes in custom bearing solutions; we can manufacture various non-standard precision bearings according to customer specifications and provide complimentary services such as model selection, design, and calculations for service life and load capacity.

Q3: What precision grades can LTZC precision robot bearings achieve?

A: Standard batch products can reach P4 precision grade, while high-end projects can be supplied with P2 ultra-precision grade bearings to meet the positioning requirements of high-precision industrial robots.

Q4: What export quality inspection documents and certifications can LTZC provide?

A: LTZC holds ISO9001 quality management system certification, and our products support third-party inspections by agencies such as BV and CCS. Upon shipment, we provide a complete set of documentation, including material certificates, heat treatment reports, and finished product precision inspection reports.

Contact LTZC for custom robot bearings.