THK (short for Toughness, High quality, and Know-how) is a world-renowned Japanese manufacturer specializing in linear motion systems. THK Linear Bearings provide smooth, accurate, and repeatable linear motion and are essential components in high-precision automation equipment.
They primarily include linear guideways, LM (Linear Motion) guides, ball screws, and linear bushings, designed to minimize friction and ensure high load-bearing capacity with exceptional accuracy.
How THK Linear Bearings Work
THK linear bearings operate on a recirculating ball or roller mechanism. These rolling elements move between the carriage (also called the block or slider) and a precision-machined rail, drastically reducing friction compared to traditional sliding bearings. The system supports smooth, high-speed linear movement while maintaining stability and precision.
Key Components of THK Linear Motion Systems
Rail (Guideway) – Hardened and ground for precision motion.
Block/Carriage – Contains the rolling elements and travels along the rail.
Rolling Elements – Balls or rollers that reduce friction.
End Seals and Scrapers – Prevent debris from entering the bearing system.
Lubrication Ports – Allow maintenance-free operation with minimal friction.
Types of THK Linear Bearings
1. LM Guide (Linear Motion Guide)
Most popular THK bearing product.
Offers high rigidity and precision.
Common models:
SHS series – High rigidity, four-way equal load.
HSR series – Global standard.
SR series – Compact version.
SSR/SHW/SNR – Various sizes and load capacities.
HRW series – Wide rail type.
SVR/SVS – High-load roller types.
2. Linear Bushings (LM Bush)
Used with linear shafts.
Ideal for low-cost linear motion systems.
Types: standard, open type, flanged, compact.
3. Cross-Roller Guides
Uses cylindrical rollers in a crisscross arrangement.
Offers high rigidity in all directions.
Ideal for applications requiring ultra-smooth, stable motion.
4. Ball Spline
Designed for torque transmission along linear paths.
Useful in robotic arms and rotary actuators.
Top Features of THK Linear Bearings
High Precision: Maintains tight tolerances, ideal for CNC and robotic systems.
High Rigidity: Roller-type models are especially suitable for heavy loads.
Smooth Operation: Recirculating elements reduce friction dramatically.
Compact Design: Suitable for space-saving applications.
Long Service Life: High durability due to hardened raceways and rolling contact.
Self-Lubricating Options: Equipped with Caged Ball technology and QZ lubrication.
Silent Operation: Caged Ball technology reduces noise and improves travel smoothness.
Equal Load Capacity in All Directions: Many series are designed to bear loads vertically, horizontally, and radially.
THK’s Caged Ball Technology
A major innovation by THK, this design separates the balls with a cage, which:
Prevents ball-to-ball contact.
Reduces friction and noise.
Improves lubrication retention.
Enhances long-term reliability and speed performance.
Applications of THK Linear Bearings
THK products are used extensively across industries, including:
Machine Tools – Lathes, milling machines, CNC routers.
Industrial Automation – Robotic arms, pick-and-place systems.
Medical Devices – Imaging machines, surgical equipment.
Semiconductor Equipment – Precision wafer handling.
3D Printers & Plotters
Transportation Systems – High-speed trains, automatic doors.
Aerospace & Defense – Actuation systems, simulators.
Benefits of Using THK Linear Bearings
Unmatched Reliability in high-load and high-precision environments.
Wide Variety of models and sizes for all types of equipment.
Maintenance-Free Operation due to effective lubrication systems.
Time-Saving Installation with modular options.
Consistent Global Availability with worldwide THK distribution.
THK LM Guide Series at a Glance
Series Feature Load Type Application
SHS Global standard, caged ball 4-way equal load CNC, automation
HSR High load, ball type 4-way equal load General industry
SR Compact design Light load Compact machines
HRW Wide rail Medium-heavy load Transportation, factory lines
SVR/SVS Roller type Very high load Heavy machining
SNR/SHW Compact/flat type Medium load Electronics, light robots
Conclusion
THK Linear Bearings set the benchmark in linear motion technology. Their diverse product range, unmatched precision, and technological innovations like Caged Ball technology make them ideal for advanced industrial, medical, and automation systems. With THK, you get guaranteed performance, long service life, and reliable motion in even the most demanding applications.
