The need to solve practical and ever more challenging issues means that regardless of age-old traditions, mechanics remains a living science. Consequently, mechanical innovation continues to evolve. Eichenberger Gewinde AG has a wealth of know-how and potential when it comes to the design of specifically integrated drive components. This is why the thread specialist – which incidentally is the only Swiss manufacturer of rolled ballscrews – supports a broad spectrum of industries, ranging from medical, electrical and automotive engineering, to textile and household appliance industries, as well as automation and general mechanical engineering.
The ecosystem of ants
Visualising the habitat of a forest ant, one sees nest domes made of pine needles, pieces of wood and pebbles, with layers of resin serving as protection against the weather. Openings on the surface are used as entrances and exits and also have a climate-regulating function. In hot weather these expand considerably in order to ventilate the nest, in rainy weather they are closed. After rainfall, the top wet layer of the nest is dug up by the intelligent ants, so that the wet is inside and the dry can once again repel the rain on the outside. The process is repeated in winter with frost and snow. One species of ant has even developed a special strategy for blocking the entrances, so that when it rains, they plug the openings with their heads.
Living space for our comfort
We humans design our living and work spaces in a surprisingly similar way to ants in order to make them as comfortable as possible for us. The focus is on safety, comfort, health, energy efficiency and aesthetics. Air, light, temperature and noise all have a significant influence on our physical well-being. Building technology is continuously developing in line with the increasing expectations. In new buildings or as part of a modernisation project, for example, top-of-the-range windows must be multifunctional and react fully automatically and dynamically to changing environmental conditions. A good indoor climate requires high-quality and plentiful fresh air, and feeling a sense of security against burglary at home or at work creates a special sense of well-being.
The magic word in the success story of the formidable ants is adaptation. Ants have conquered practically all habitats in the world. The very first of their kind are believed to have walked the earth during the age of the dinosaurs. They have an extraordinarily long and impressive list of abilities. Moreover, researchers are discovering new characteristics of these industrious, extremely strong creatures virtually every month.
Being truly adaptable is where the cold-formed ballscrews from Eichenberger really excel. The similarity between the efficient ant colony and the strong ballscrews, renowned for their impressive size/performance ratios as well as being robust, efficient and precise, is astounding. It is not only the quality of these motion spindles that makes them outstanding, they also provide an elegant and effective solution for almost all applications. At Eichenberger, the focus is always on a needs-oriented, constructive exchange with our customers. The art is to find an ideal solution for the customer, while at the same time ensuring optimum production.
Thread forms beyond the norm present the challenges we seek. Eichenberger is always exploring boundaries and has a passion for venturing into new profile shapes, exotic materials and dimensions. This kind of flexibility and adaptability only works if a vast wealth of experience is available, combined with profound quality awareness amongst the team and a correspondingly modern range of machinery.
Ballscrew Carry type ZYI
The need for dynamics in a small space
A leading manufacturer was looking for a suitable drive component for a newly developed, fully automatically controlled window locking system. A customised motion element needed to be installed in a concealed position in a small window fitting for a tilt ventilation system. The company was looking for a flexible development partner with a lot of experience, as there were a number of hurdles to overcome. In particular, the enclosed installation conditions proved to be a challenge, as the space available was very limited. Load, humidity and condensation as well as service life were the most important factors in the specifications. Furthermore, the drive solution had to have an additional drive pin for connecting additional construction elements and meet the remaining quality requirements such as speed and accuracy.
For Eichenberger, it was clear that only a ballscrew would be up to the task because of the high coefficient η of over 0.9 and the associated energy efficiency. The designers decided to use a corrosion-resistant Carry ballscrew with a small diameter of 8 mm and 1.5 mm pitch as the basic element. The integrated ball-return in the nut can handle the smallest of dimensional requirements, as was the case with this window fitting component. The developers completely redefined the outer geometry of the nut and mounted the drive pin supplied by the manufacturer on it. It was possible to leave the interior of the nut unchanged according to the specifications, resulting in a considerable price advantage. In addition, an anti-rotation construction was installed.
This may sound simple, but in fact it is only possible with very close teamwork, as is the case with Eichenberger. . Development, production and quality assurance work hand in hand. The rolling tools can also be manufactured "in-house", so prototypes can be realised within a very short time. Thanks to these factors, flexible and competitive production is possible eve in an expensive location such as Switzerland.
Ballscrew Carry, rolled and hardened, the ideally adapted
Today, state-of-the-art window systems perform perfectly, ventilating automatically, darkening in bright light and reacting automatically to rain and wind. In addition, it detects if burglars are at work or if a window is unintentionally left open. The " self-thinking" window can thus interact with other home technologies. The small, customised mini ballscrew drive integrated in the hardware manages closing, locking, unlocking and tilting reliably and precisely.
So how can the Carry ballscrew with a length of 8 x 1.5 mm withstand such high loads and still be so precise, with such a convincing service life and reliability?
The core competencies of Eichenberger Gewinde AG lie in thread rolling and hardening. Thread rolling is the cold forming of the surface of round workpieces. The thread is produced by forming the component under enormous force between two rotating rolling tools. As the rolling tool profiles penetrate the surface of the workpiece, the material is pressed cold to the bottom of the thread rolling tools and rolled up to the specified dimension. The usual manufacturing processes for threads such as milling, turning or whirling involve metal-cutting.
These processes have the disadvantage of interrupting the fibre flow of the steel. In contrast, thread rolling is a non-cutting process that does not cut the longitudinal fibres, but merely redirects them. Depending on the material, an increase in strength of 30 to 50 % is achieved. At the same time, the surface of the profile is hardened; this "smoothly controlled surface" offers little opportunity for contamination and ensures low-noise rolling of the balls. This is crucial for a long service life.
Furthermore, thread rolling results in very good roughness values (around Rz 1.0) on the thread flanks and in the base radius, resulting in significantly reduced groove sensitivity. Eichenberger has acquired additional valuable know-how through years of in-house experience in induction hardening. Whereas a hardening shop is dedicated exclusively to hardening steel, the thread specialist strives to obtain the best possible combination of hardness and precision. Given the extensive variety of diameters offered by the thread rolling specialist, it is particularly important to determine the ideal tolerance position in order to achieve the best possible accuracy.