Precision Linear Bearings
Precision Linear Bearings & Recirculating Units
SCHNEEBERGER linear bearings cover both linear bearings (limited stroke) and recirculating units (long stroke)
From ultra-smooth motion to extreme heavy loads, providing optimal linear motion support for precision machine tools, semiconductor and medical equipment
Linear Bearings
Rolling elements guided by cages provide extremely high motion smoothness and rigidity for limited stroke precision applications
Type R / RD
Cross Roller Cage Guideways
- First standardized cross roller guideway
- Ball or roller options available
- RD double V-groove saves space
- Defines global industry standards
Type RN
Narrow Cross Roller Guideways
- Optimized version of Type R
- Same mounting dimensions, higher performance
- Smaller clearance, better contamination protection
- Optional FORMULA-S cage centering device
Type RNG
Cross Roller Cage Guideways
- Based on Type R, smaller cross-section
- Cost-effective without compromising performance
- Performance comparable to RN
- Optional FORMULA-S cage centering device
Type N / O
Needle Cage Guideways
- Needle cage, high load capacity
- Composite cage reduces movement resistance
- Suitable for high-load applications
- Optional cage centering device (200 m/s²)
Type M / V
Needle Cage Guideways
- Needle cage, similar to N/O
- Different external dimensions from N/O
- Composite cage reduces movement resistance
- Optional KZST cage centering device (200 m/s²)
| R / RD | RN | RNG | N / O | M / V | |
|---|---|---|---|---|---|
| Rolling Element | Cross Roller (Ball optional) | Cross Roller | Cross Roller | Needle | Needle |
| Stroke Type | Limited | Limited | Limited | Limited | Limited |
| Motion Smoothness | +++ | +++ | +++ | ++ | ++ |
| Load Capacity | ++ | +++ | +++ | ++++ | ++++ |
| Max Speed | 1 m/s | 1 m/s | 1 m/s | 1 m/s | 1 m/s |
| Rail Hardness | 58–62 HRC | 58–62 HRC | 58–62 HRC | 58–62 HRC | 58–62 HRC |
| Temperature Range | -40 ~ +80°C | -40 ~ +80°C | -40 ~ +80°C | -40 ~ +80°C | -40 ~ +80°C |
| Max Rail Length | 3,000 mm R9/R12 NQ | 3,000 mm RN 9/12 NQ | 3,000 mm RNG 9/12 NQ | 3,000 mm N/O 92025+ NQ | 3,000 mm M/V 4020+ NQ |
| Max Cage Length | 1,500 mm AC 6/9/12 | 1,500 mm KBN 6/9/12 | 1,500 mm KBN 6/9/12 | 1,500 mm SHW/SH | 1,500 mm SHW/SH |
Recirculating Units
Rolling elements recirculate continuously with no stroke limitation, suitable for applications requiring long-distance linear motion
Type SK
Recirculating Ball Bearing Units
- Ball recirculation design, standard height
- Multiple sizes (1, 2, 3, 6, 9, 12)
- Redirection units in aluminum or plastic by size
- Optional height matching (GP)
Type SKD
Recirculating Ball Units with Damping
- Ball recirculation with plastic damping elements
- Best motion smoothness (++++)
- Excellent noise reduction performance
- Optional height matching (GP)
Type SKC
Ceramic Recirculating Ball Units
- Ceramic balls with PTFE ball spacers
- Operating temperature -150°C to +200°C
- Best motion smoothness (++++)
- Optional height matching (GP)
Type SR
Recirculating Roller Bearing Units
- Roller recirculation design
- Higher load capacity than ball type (+++)
- Redirection units in plastic or aluminum by length
- Optional height matching (GP)
Type NRT / NRV
Recirculating Roller Tables
- Roller recirculation, highest load capacity (++++)
- Rail and table integrated as one unit
- Ready to install, no alignment needed
- Optional central lubrication connection (ZS)
| Feature | SK | SKD | SKC | SR | NRT / NRV |
|---|---|---|---|---|---|
| Rolling Element | Ball | Ball (with damping elements) | Ceramic Ball (PTFE spacers) | Roller | Roller |
| Motion Smoothness | +++ | ++++ | ++++ | ++ | ++ |
| Load Capacity | ++ | ++ | + | +++ | ++++ |
| Max Speed | 2 m/s | 2 m/s | 2 m/s | 2 m/s | 1 m/s |
| Max Acceleration | 50 m/s² | 50 m/s² | 50 m/s² | 50 m/s² | 50 m/s² |
| Operating Temperature | -40 ~ +80°C | -40 ~ +80°C | -150 ~ +200°C | -40 ~ +80°C | -40 ~ +80°C |
| Stroke | Unlimited | Unlimited | Unlimited | Unlimited | Limited (table length) |
Product Features
SK Series
Standard ball recirculating units offering balanced performance and cost-effectiveness
SKD Series
Ball recirculating units with damping elements for superior smoothness and noise reduction
SKC Series
High-temperature ball recirculating units operating in extreme temperatures from -150°C to +200°C
SR Series
Roller recirculating units providing good load capacity and smooth operation
NRT Series
Heavy-duty roller recirculating units with the highest load capacity
Application Guide
Select the appropriate recirculating unit type based on your application requirements:
- High-speed precision applications - Choose SKD (damped) or SKC (high-temp) for best smoothness
- Standard automation applications - SK series offers the best value
- Heavy-load applications - NRT series roller recirculating units have the highest load capacity
- Extreme temperature environments - SKC series withstands -150°C to +200°C temperature range
- Medium-load applications - SR series roller recirculating units provide balanced performance
Surface Treatments & Special Versions
Advanced options for special environments and application requirements
Real Industry Applications
Linear guideway system solutions for machine tools, semiconductor, medical equipment and more
Machine Tools & Grinders
Tool Grinder Table
Precision grinding requires stick-free, frictionless guideways for longitudinal table movement.
Internal Grinder Table Bearing
Absolutely zero-backlash guidance, V-shaped needle roller cage with oil pulse lubrication system for controlling high table speeds with minimum force.
Heavy Surface Grinder (Open)
Surface-mounted roller guideways absorb vertical loads and prevent thermal expansion effects. Cost-effective and simple to assemble.
Surface Grinder (Enclosed V-Type)
V-configuration absorbs forces and moments in all directions. Fewer components ensure fast assembly, with roof-shaped base for efficient machining.
Heavy Tool Grinder (V-Guide)
RNG roller guideways with high load capacity. Table structure accommodates drive mechanisms, preload can be easily set afterwards.
Large Machining Centers
Rigid and precise linear guideway systems are essential for high-precision manufacturing under the most demanding loads.
with preload wedge NRV
Semiconductor & Precision Equipment
Wire Bonder
Wire bonding is the preferred method for making connections between integrated circuits (ICs) and printed circuit boards, using aluminum, copper or gold wire starting from 15 µm diameter. Requires the highest precision, rigidity, speed and smoothness.
25 µm diameter aluminum wire connecting microchip electrodes to carrier substrate conductor traces
Vacuum Feed Device
Feed devices operating in vacuum impose very high demands on linear guideway systems. The U-profile forms the support element and also serves as the mounting base for the linear guideways. The entire system is made of non-corrosive materials, works vertically with a 2,700 mm stroke.
The linear guideways and 4 type SK rolling elements assembled in the U-profile base form the actual guidance system. Two of the four rolling elements can be externally adjusted to support optimal preload settings. All individual components of the rolling elements are made of stainless steel or aluminum.
Medical Equipment
CT / MRT Patient Table
Automated tables for CT and MRI scanners requiring running precision, smoothness, maintenance-free operation and radiation resistance.
Microtome
Producing 1–100 µm ultra-thin sections for biological tissue microscopy preparation or plastic analysis, with the strictest requirements for smoothness and precision.
View Complete Technical Documentation
Includes detailed dimension tables, load ratings, installation guides and selection tools