The need to solve practical and ever more demanding tasks means that mechanics, despite thousands of years of tradition, always appears to be a living science. The development of mechanics will therefore never be complete. Eichenberger Gewinde AG offers a great deal of know-how and potential when it comes to the design of specifically integrated drive components. The thread specialist - incidentally the only manufacturer of rolled ball screw drives in Switzerland - serves a wide range of industries, from medical, electrical and automotive engineering, through the textile and household appliance industries, to automation and general mechanical engineering.
The ants' housing system
If you look at the habitat of a wood ant, you can see nest domes made of pine needles, pieces of wood and pebbles. A layer of resin serves as protection against the weather. Openings can be seen on the surface, which serve as entrances and exits and have a climatic function. In hot weather, these are widened considerably in order to ventilate the nest, while they are closed when it rains. The top layer of the nest that has become wet is dug over by the clever ants after rainfall so that the wet is inside and the dry can once again repel the rain on the outside. The same happens in winter when there is frost and snow. One particular species of ant has even developed a special tactic for blocking the entrances. When it rains, they block the entrance holes with their heads.
Living space in which we feel comfortable
We humans design our living and working spaces in a surprisingly similar way to make them pleasant for us. The focus is on safety, comfort, health, energy efficiency and aesthetics. Air, light, temperature and noise have a significant influence on our physical well-being. Building technology is being consistently developed to meet the increasing requirements. Whether in a new building or as part of a modernization project, the top class of windows, for example, should be multifunctional and react fully automatically and dynamically to changing environmental conditions. A good indoor climate requires a high-quality and sufficient supply of fresh air, and if people also feel burglar-proof at home or at work, they are particularly comfortable.
Adaptability
The magic word in the success story of the admirable ants is adaptation. Ants have conquered practically every habitat in the world. The first of their kind are said to have walked the earth during the lifetime of the dinosaurs. The list of their abilities is extraordinarily long and distinctive. What's more, researchers are discovering new characteristics of these industrious, extremely powerful little animals almost every month.
The cold-formed ball screws from Eichenberger are also about real adaptability. The similarity between the efficient ant colony and the strong ball screws, which have also made a name for themselves with their enormous size/performance ratios as well as their robustness, efficiency and precision, is astounding. Not only in terms of the quality of these motion spindles, but also in terms of "application", they offer an elegant and effective solution for almost all requirements. At Eichenberger, the focus is always on a needs-oriented, constructive exchange with the customer. The trick is to find the ideal solution for the customer, which of course also ensures optimum production.
Thread forms that are outside the norm are the challenges we are looking for. Eichenberger is constantly pushing the boundaries and passionately ventures into new profile shapes, exotic materials and dimensions. Such a high degree of flexibility and adaptability only works if a wealth of experience is available, coupled with a deep awareness of quality on the part of the employees and correspondingly modern machinery.
Demand for dynamics in a small installation space
A leading manufacturer was looking for a suitable drive component for its new development, a fully automatically controlled window locking system. A customized motion element was to be concealed and installed in a small window fitting for a tilt ventilation system. A flexible development partner with a lot of experience was needed, as there were a number of obstacles to overcome. Above all, the kinematic conditions presented a challenge, as space was very limited. Load, moisture and condensation and service life were the most important factors in the specifications. Furthermore, the drive solution also had to include a driver for connecting other design elements and meet other quality requirements such as speed and accuracy.
Challenge accepted
It was clear to Eichenberger that only a ball screw drive would be up to the task due to its high efficiency η of over 0.9 and the associated energy efficiency. The design engineers decided to use a corrosion-resistant Carry type ball screw with a small diameter of 8 mm and a pitch of 1.5 mm as the basic element. The integrated ball deflection in the nut makes it possible to cope with the smallest dimensional specifications, as is the case with this window hardware component. The developers completely redefined the outer geometry of the nut and mounted the driver part supplied by the manufacturer on it. The inner workings of the nut could remain unchanged according to the requirements, which resulted in a decisive price advantage. In addition, a design for the anti-rotation lock was installed.
What sounds so simple is only possible if the team works very closely together. This is the case at Eichenberger. Development, production and quality assurance work hand in hand. The rolling tools can also be manufactured "in-house", meaning that prototypes can be produced within a very short time. Thanks to these factors, production can be flexible and competitive even in an expensive location such as Switzerland.
Carry ball screw drive, rolled and hardened, the ideally adapted functional element
Today, the ultra-modern window system does a perfect job. It ventilates automatically, darkens in bright light and reacts just as automatically to rain and wind. It also reports if burglars are at work or if a window is left open unintentionally. The "thinking" window can therefore interact with other home technologies. The small, tailor-made mini ball screw drive integrated into the fitting manages the closing, locking, unlocking and tilting reliably and precisely.
How is it possible that the Carry ball screw with a length of 8 x 1.5 mm can withstand such high loads and also be so precise, and that its service life and reliability are so impressive?
The core competencies of Eichenberger Gewinde AG lie in thread rolling and hardening. Thread rolling is the cold forming of the lateral surfaces of round parts. The thread is produced by deforming a workpiece under enormous force between two rotating rolling tools. As the rolling tool profiles penetrate the surface of the workpiece, the cold material is pressed into the base of the thread rolling tools and rolled up to the nominal size. The usual manufacturing processes for threads, such as milling, turning or whirling, are machining processes.
These have the disadvantage that they interrupt the grain flow of the steel. Thread rolling, on the other hand, is a non-cutting process that does not cut the longitudinal fibers but merely diverts them. Depending on the material, an increase in strength of 30 to 50 % is achieved. At the same time, the surface in the profile hardens, this "smooth surface" offers little opportunity for dirt to accumulate and ensures that the balls roll quietly. This is crucial for a long service life.
Thread rolling also results in very good roughness values (around Rz 1.0) on the thread flanks and in the base radius, resulting in significantly reduced notch sensitivity. Thanks to its many years of experience in induction hardening in-house, Eichenberger has also acquired valuable know-how. While a hardening store is dedicated exclusively to hardening steel, the thread specialist strives to achieve the best possible combination of hardness and precision. With the very wide range of diameters offered by the thread roller, it is particularly important to find out where the ideal tolerance position is in order to achieve optimum precision.
