Hyprostatik: Hydrostatic basic machine for ultra-fine grinding

Hyprostatik Schönfeld, one of the market leaders for hydrostatic components, has developed a high-precision hydrostatic base machine for a new ultra-precision grinding center from Optotech. The machine platform forms the heart of the system and, according to the manufacturer, enables a combination of dimensional accuracy, dynamics and surface quality that has never been achieved before in the ultra-fine grinding of optical surfaces. The basic machine is based on a solid granite bed, which creates ideal conditions for ultra-precision machining thanks to its thermal stability and high inherent damping. A cross-slide with hydrostatic guide shoes travels on it, performing the horizontal movements in the X and Y directions. The axes are driven directly by linear motors and enable backlash-free, highly dynamic positioning. The vertical hydrostatic Z-axis is attached to the front of the granite bed. It is driven by a hydrostatic screw drive with integrated hydrostatic bearing.

Hydrostatic basic machine for maximum precision and surface quality

The very rigid design of the machine and the finishing of all relevant components on hydrostatic grinding machines result in a straightness of movement and positioning accuracy that is several times better than comparable systems with roller guides. The slides float friction-free on hydrostatic pockets. As a result, travel steps of less than 0.1 µm and a backlash of less than 0.1 µm can be achieved. Thanks to the non-contact guidance, the axes operate completely wear-free and maintain their accuracy consistently over many years. Another advantage of the hydrostatic guide is its excellent damping. This increases the path accuracy, particularly at high dynamics, and has a direct positive effect on the achievable surface quality of the workpieces. High accelerations also enable short machining times with maximum precision. A hydrostatic workpiece spindle is mounted above the vertical axis. This achieves a axial and radial run-out of 0.1 µm, even in high speed ranges. This exceptional running quality is directly transferred to the shape accuracy and surface quality of the machined optical components.