5 years ago

MDA Technologies 1/2016

MDA Technologies 1/2016

HPLS: Precision, power

HPLS: Precision, power density and stiffness for linear motion control DRIVE TECHNOLOGIES Linear motion control as a high-end system solution – that just about sums up Wittenstein alpha’s High Performance Linear System HPLS. In the newest FZ37 generation of portal milling machines from F. Zimmermann GmbH, it meets even the strictest requirements for smooth yet dynamic motion control, high acceleration and speeds in any axis, with modular and easy installation, maximum integration regardless of the axial length and maximum system rigidity for high precision, high speed cutting (HSC). Author: Guido Brenner, Wittenstein alpha GmbH, Manager Sales Office South-West, Ludwigsburg, Germany The HPLS is a rack-and-pinion system comprised of an ultra lowbacklash planetary gearhead in the RP+ series with a welded, helical-toothed pinion and a precision manufactured rack. All its components come from one source and interact optimally in any application – for the best possible performance in terms of torque and holding torque for feed and acceleration, smooth running, power density, freedom from backlash and system rigidity when highly dynamic and precise motion control of linear axes is called for. “As far as these relevant parameters are concerned, the HPLS performs significantly better than the market standard”, confirms Hartmut Kälberer, the President of F. Zimmermann GmbH. “What’s more, 01 Zimmermann’s new FZ37 portal milling machine meets all of the requirements for innovative milling solutions 34 MDA Technologies 1/2016

the systems can be designed very flexibly to match the axial lengths. At the same time, both the gearhead and the rack incorporate special design features such as slots integrated in the gearhead flange or racks with a highly precise and ergonomic eccentric mounting system, so that they are much easier to install than conventional drive solutions of a similar kind.” HPLS for complex milling solutions As a result of these characteristics, the HPLS fulfils several basic conditions for complex milling solutions. Their evolution has been especially dynamic and coupled to steadily increasing demands. Development cycles are shorter than ever, as is the time to market. Prototypes – preferably already perfected – have to be realized more and more rapidly. “Speed, dimensional accuracy and surface finishes of a very high quality are typical expectations for milling solutions along with versatility and flexibility”, Kälberer explains. “Our newest generation of portal milling machines is capable of cutting not only light alloys, plastics and composite materials but also steel and cast iron. That’s why the machines used to manufacture high volume parts in the automotive, aerospace and toolmaking industries or the railway and energy sectors tend to have a large work area. High dynamics and maximum system rigidity are equally vital.” HPLS for optimum performance in milling machines Zimmermann’s new FZ37 portal milling machine meets all the requirements for innovative milling solutions. At their home office in Neuhausen auf den Fildern, not far from Stuttgart in south-west Germany, Zimmermann designs, develops and manufactures highend portal milling machines for the most diverse industrial applications. For more than a decade now, the company has trusted in rack and pinion systems from Wittenstein alpha. “Our customers value Zimmermann as a partner with a high level of expertise: apart from the actual milling machines, our portfolio also includes automation systems, intelligent clamping technology, additional tools, extraction systems”, Kälberer adds. The FZ37 series is distinguished by excellent dynamics and removal rates, surface finishes of the highest possible quality, outstanding dimensional accuracy and work areas made to measure. These areas can be truly enormous: “The machine supports working ranges of up to 40 metres in the X axis, 6 in the Y axis and 3 in the Z axis – which in extreme cases can mean an incredible 720 metres cubed”, reports Marcus Lengerer, Marketing Manager at Zimmermann. “The FZ37 allows 5-sided multi-axis machining within the work area, so that even very complex shapes can be milled from a block of material in just a short time.” From delicate precision machining to surface machining over a large area, thanks to the HPLS, this linear motion control system meets every one of the portal milling machine’s performance requirements, such as speeds up to 60 m/min or 5 m/s² acceleration. HPLS rack-and-pinion drives enable decisive improvements Integrating the HPLS in the X, Y and Z axes of the FZ37 enables decisive improvements compared to the predecessor series. The RP+ high performance planetary gearhead, for instance, is a rotary component with high torsional and tilting rigidity and a stiff connection to the machine that reduces the position error to a minimum. In combination with the rack’s remarkable precision this results in an extremely stiff machine structure and hence very high 02 The HPLS rack-and-pinion system is comprised of an ultra-lowbacklash planetary gearhead with a welded, helical-toothed pinion and a precision manufactured rack system rigidity over the entire axial length of the FZ37. The optimized KV factor permits high speeds and acceleration in all axes during high speed cutting (HSC) operations. The machine’s true-to-path motion system also ensures extreme precision: with a volumetric accuracy of up to 55 µm the FZ37 satisfies even the highest demands for surface quality and precision. The RP+ gearhead for the Z axis is designed to completely absorb all forces acting on it. “That’s why we were able to build the machine without hydraulic weight compensation”, says Kälberer. “The FZ37 needs fewer parts because we dispensed with the hydraulics. It’s easier to control and much more straightforward to install and maintain. Furthermore, the better efficiency means ongoing energy costs are significantly lower than with either the hydraulic concept or alternative solutions with a linear motor.” The drive design with the modular HPLS rack-and-pinion system simultaneously has the advantage that there are no restrictions on the length of the machine and its axes and that even large strokes are not a problem. “That not only avoids the limitations inherent to ball screws; it also facilitates a rapid and technically feasible response to specialized customer requirements regarding the axial lengths.” Kälberer comments. Photographs: Wittenstein AG About Wittenstein The Wittenstein Group is an expert in mastering the continued development of all the relevant technologies of mechatronic drive technology. They have united eight strong fields of business under one roof. Amongst other things they develop, produce and sell high-precision planetary gearheads, complete, complete electromechanical drive systems, as well as AC servo systems and motors. Their fields of application include robots, machine tools, medical technology as well as aerospace. MDA Technologies 1/2016 35