Schaeffler has developed the HLE range of hydrostatic linear guides, designed to combine exceptional damping characteristics with the compact dimensions of a standard profiled linear guide. These guides are ideal for linear motion applications where vibration control at the load point is critical, such as in high-speed machining and high-precision grinding.
With the demand for higher dynamics and power densities in machine tools, manufacturers require linear guidance systems that deliver:
High dynamic rigidity
Reduced vibration
Improved machining accuracy
By effectively dampening machine vibrations, the HLE guides enable:
Higher cutting capacities
Faster machining speeds
Enhanced surface quality
Greater machining precision
Unlike conventional ball or roller linear guides, the HLE guides operate with no metal-to-metal contact. Instead, the carriages glide on a thin film of high-pressure fluid, ensuring:
Zero wear of the guideways
Virtually infinite bearing life
Consistent rigidity and precision
The integral hydraulic controller makes the guides ready-to-fit, while mounting dimensions remain interchangeable with standard monorail guidance systems.
Vibrations in machining are caused by tool wear, cutting shocks, regenerative chatter, and other external influences. The hydrostatic film in HLE guides provides damping through the “squeeze film” effect, which:
Reduces resonance amplitude
Improves dynamic rigidity
Enhances accuracy and stability
This allows machine tools to achieve greater performance and efficiency even under demanding conditions.
For example, the size 45 HLE hydrostatic linear guide features:
Damping value: >470,000 kg/s
Operating pressure: 100 bar nominal
Oil viscosity: ISO VG 46
Flow rate per carriage: ~1.2 L/min
Tensile rigidity comparable to rolling-bearing supports
The design includes a steel saddle plate with pressure pockets and integrated pressure regulation for consistent operation.
Since there is no wear on the guideways, hydrostatic guides can be considered to have infinite bearing life, extending both machine life and long-term precision. Additionally, crash protection is enhanced—as cutting load increases, oil pressure rises to create a restoring force, preventing fluid gap closure under heavy impact.
Tests on machining centers and grinding machines confirmed the HLE’s superior performance:
Machining Centers: When fitted to the Y- and Z-axes, HLE guides showed almost identical rigidity to roller monorail systems, but with significantly reduced vibration peaks. This stabilized cuts and allowed for greater machining depths without chatter.
Grinding Machines: Replacing roller carriages with hydrostatic carriages reduced vibration amplitudes at the workpiece table. Surface measurements showed that HLE guides improved both long waviness and short waviness.
Hydrostatic guidance systems were historically viewed as expensive, bulky, and time-consuming to install. However, Schaeffler’s INA HLE guides overcome these barriers by fitting within the standard design envelope of profiled rail linear guides.
For machine builders, this means:
Lower design and assembly costs
Compatibility with ISO/DIN standards
Flexibility to mix roller and hydrostatic systems within the same machine design
Schaeffler’s HLE hydrostatic linear guides provide a breakthrough solution for the machine tool industry, offering compact design, superior damping, and extended durability. With proven results in machining and grinding applications, the HLE range ensures higher accuracy, longer machine life, and improved efficiency, making it a strong alternative to conventional roller or ball guides.