Hydrostatic linear guide package offers benefits

Schaeffler Group's HLE range of hydrostatic linear guides is said to be ideal for use in high speed machining and high precision grinding applications.

The HLE range combines excellent damping with the compact dimensions of a profiled rail linear guide. Unlike conventional ball linear guides or roller linear guides, the hydrostatic guides feature no metal-to-metal contact. The guide carriages move on a thin cushion of high pressure fluid, the end result being zero wear of the guideways. An integral hydraulic controller means the hydrostatic guides are ready-to-fit and the mounting dimensions are interchangeable with monorail guidance systems. One test of the technology involved evaluating the hydrostatic guide on a 3-axis machining centre. The transverse axis (Y-axis), which guides the main spindle assembly and the Z-axis, were fitted with a size 45 hydrostatic guide. Measuring the deflection showed that the HLE had almost identical values to the roller monorail guidance system, indicating that there were no disadvantages in terms of axis rigidity. However, on examination of the dynamic resilience in the machine tool centre point, this revealed a clear reduction in vibration peaks in all axes when using the HLE. This enabled a significant increase in the maximum machining depth. Tests by the customer showed that the cut becomes unstable at a certain machining depth when using monorail guidance systems, with regenerative chatter effects occurring. However, under the same conditions, when HLE technology is employed, the cut is stabilised. Similar positive results were revealed on workpiece table vibration on a grinding machine.