Whether grinding, turning, milling machine or entire machining center – our hydrostatic technology enriches every machine tool. In addition to comprehensive calculation programs, HYPROSTATIK customers benefit from our innovative progressive flow controller. Thanks to its unprecedented design, up to four times increased stiffness is achieved, resulting in above-average precision.
Considerations on the development direction of machine tools in particular.
Not only the uncertainty regarding the development of the euro, but also the pandemic, the quality of political leadership, the clouds of “climate change”, the “crisis of the combustion engine”, etc. can significantly burden the machine tool industry of Europe in the future, or is already burdening it.
In view of this situation, the machine tool industry will have to look for ways of countering a further, possibly significant downturn, i.e. how to cut off a larger share of the shrinking pie.
If the less attractive option of achieving success by means of low prices or high discounts is placed in the second row, the further development of machine tools is the most important way of achieving this goal.
– higher performance, so more parts of the same quality,
– higher quality of the parts, i.e. higher dimensional accuracy and surface quality as well as lower scrap rate,
– higher universality, e.g. due to suitability also for high-precision hard machining, and higher precision,
– lower production costs due to
longer tool life,
Reduction of maintenance costs,
higher availability of the machines
reduced energy demand and
longer machine service life.
– Possibility to control the machining parameters and the machine load.
These goals can be achieved through
Hydrostatic components HYPROSTATIK® system
i.e. hydrostatic guides, rotary tables, screw drives with hydrostatic nut and various types of hydrostatic spindle bearings.
Hydrostatic components from HYPROSTATIK Schönfeld GmbH are based on the wear and maintenance-free PM controller (Progressive Flow Controller ), which has proven itself for more than 30 years, extensive calculation programs, by means of which hydrostatic systems can be optimized not only with respect to static but also dynamic loads, and on more than30 years of experience as well as mature products.
Compared to other hydrostatic systems available on the market, these requirements result in approximately four times the stiffness, much higher loads, significantly lower power losses, and, especially in the case of spindle bearings, significantly higher speeds, whereby these speeds are permissible with unrestricted load capacity, in contrast to alternative systems. Furthermore, by calculating the damping values, much higher damping absorption capacities are usually achieved than with alternative hydrostatic systems, in particular, however, compared to largely undamped spindle bearing arrangements with rolling bearings.
As early as 1996, HYPROSTATIK® was the only supplier to succeed in supplying threaded drives with hydrostatic nuts whose axial stiffness values are approximately double those of comparable ball screw nuts.
The properties of all hydrostatic components from Hyprostatik are characterized by
Wear-free, leads to
– a reduction in maintenance costs,
– to higher availability of the machine and
– to longer machine service life.
– to consistent machine properties regardless of the machine’s service life.
High damping, leads to
– higher surface quality,
– higher marginal metal removal rate,
– higher universality, due to higher surface quality and marginal cutting performance wider application and possibly also hard machining
By recooling the oil slightly below the rack temperature of the machine or the room temperature, not only are the energy losses of the hydrostatic (pump and friction power) kept away from the machine, but also the machine is controlled to a constant temperature, so that in many cases thermosymmetrical design can be dispensed with. This also prevents a heat drift largely avoided after the machine is switched on.
The frictional force, especially in guides, is very small and proportional to the speed, even with the heaviest machine parts, so there is no jump in the feed force when the direction of movement is reversed, e.g. best path fidelity of machine slides.
Rundlauf, web fidelity
Due to the integrating effect of hydrostatics, form errors of the guiding surfaces with small extension compared to the pocket length are largely suppressed. Due to this, radial and axial hydrostatic bearings Radial and axial runout < 0.1 µm are possible. The precision of slide movements as well as the path accuracy of simultaneous movements of several slides also benefits from this property of hydrostatic systems. Furthermore, the path fidelity of the simultaneous movement of several carriages benefits above all from the Proportionality of the friction force to the carriage speed mentioned in the previous section under friction behavior: When the direction of movement of a carriage is reversed, the position error depends exclusively on the position measuring system and the quality of the Slide drive off. For example, deviations in the nanometer range are possible in a circular motion, so that completely new machine concepts are also possible.
Additional possibilities with hydrostatic systems
Another advantage of hydrostatic systems results from the possibility to measure the pressures in the hydrostatic pockets: From this, both the machine can be protected against overload and process data can be derived from these pressures.
Furthermore, a cylindrical radial bearing allows both rotary and linear movements. Separation of the rotary and linear motion, as is necessary with rollingbearings, can be omitted. In addition, a maximum spindle diameter can be realized in the case of restricted housing outer dimensions: In the case of a rolling bearing, the spindle diameter is reduced by the difference between the rolling bearing inner and outer diameters ; in the case of a hydrostatic bearing arrangement, the spindle diameter can be identical to the rolling bearing outer diameter!