Eichenberger has developed a cold-rolled ballscrew. This ingenious, highly sophisticated ball return system sets new standards in a variety of respects, and most notably in terms of price.
Powering ahead with full innovation
Designers routinely have to determine the appropriate drive technology required for linear motion. The use of rolled ballscrews is firmly established in linear automation, and nothing compares to cold-formed spindles. Eichenberger - which happens to be the only manufacturer of rolled ball screws in Switzerland - serves a wide range of industries, including the medical, electrical and automotive sectors, the textile and building industries, automation and general mechanical engineering, all the way to the aerospace industry.
The customer is always the central focus
As a thread specialist, unconventional thread forms provide the challenges we are looking for. The Eichenberger design engineers actively engage with our customers to understand their requirements in a consultative, solution-oriented dialogue to provide optimal solutions. For Eichenberger, the competitive and successful ideas of partners combined with inspiring exchanges are the driving force for new developments. Quality begins with the focus on the customer and ends with their satisfaction. Today, technological advancement and enhanced performance are prerequisites, coupled with a trend towards reducing investment costs. The same applied to the development of the Type F ballscrew.
Characteristics: Extremely cost optimized
Innovation arising from experience:
The new Type F Carry ballscrew drive
Development, production and quality assurance are all provided under one roof at Eichenberger. Direct "in house" access and modern machinery enable maximum flexibility and strengthen the innovation process. For example, our designers successfully developed a new, efficient manufacturing process for the production of a special ball screw nut with an extremely sophisticated deflection system in a single operation. The new F-type ballscrew, a further development of the Carry ballscrew, made its debut. This masterpiece may appear as a plausible basic idea. However, behind Eichenberger's core manufacturing competencies are special qualities that deliver real advantages.
With this deflection system, spindles are available in diameters from 6 to 40 mm,
available in pitches from 2 to 40 mm.
Rethinking old ideas
In the case of ballscrews, balls transmit the load from the spindle to the nut. The mechanical efficiency of a traditional lead screw does not usually exceed 0.4, compared to 0.9 with ballscrews. This energy efficiency makes the thread drive one of the most widely used drive components. The nut features a return system that steers the balls back to their initial position.
With the Type F ballscrew, the balls leave the thread channel of the nut in the return system and are caught by a special, highly refined, precise recess in the cap, then directly deflected and returned through the body of the nut. In the end cap, the deflection takes place again into the thread channel, where the ball "lines up" to execute the task assigned of transmitting the load with low rolling friction. It is essential that the balls roll smoothly and silently as they pass from the nut into the deflection channel. And they do. The ingenious design of the nut body combined with state-of-the-art, fully automated manufacturing methods results in an impressive cost-optimised product.
This cold-rolled Type F delivers as promised
When it comes to competition, customers invariably opt for the supplier offering the greatest advantages. Today, the trend is towards smaller spindles with larger pitches, and this is referred to as "square" (pitch ≙ spindle diameter) and even " over-square" spindles. The new deflection system offers 6 to 40 mm diameter spindles with pitches from 2 to 40 mm. The Type F integrated ball-return element made of high-performance plastic was also developed for large quantities and can be produced at very attractive prices thanks to a cost-saving manufacturing process. Endurance tests at top speed and under maximum load testify the quality features and confirm the outstanding performance of the new deflection system.
The core competencies of Eichenberger Gewinde AG lie in thread rolling and hardening. Enhanced strength resulting from cold forming plays a lesser role in the production of ball screws than it does in the case of sliding screws. More crucial is the continuity of the ball screw profile, achieved by transferring the solid shape of the extremely stable thread rolling tools to the spindle. An equally important factor is the extremely finely compacted surface finish of the profile. This degree of precision (roughness values ~ Rz 1.0) ensures minimal contact surface for contamination and also facilitates low-noise rolling of the balls. Friction is reduced by the smooth surface and the rolling motion of the balls, thus significantly increasing efficiency. Consequently, drive torque remains low and self-heating is minimised which reduces power consumption and lowers operating costs.
Years of experience with in-house induction hardening have given Eichenberger a great deal of know-how. Unlike a hardening shop dedicated exclusively to hardening steel, the thread specialist strives to achieve the best possible combination of hardness and precision. This is crucial for obtaining the high pitch precision of the ballscrew on the impressive range of diameters. This is especially critical for small dimensions, as the smaller the diameter, so the greater the expertise and sensitivity required in the hardening process. Previously, such high precision was only possible with machined spindles.