The call from faraway Russia came around lunchtime - from a small town called Novoaltaisk near the Mongolian border. The man on the other end of the line was interested in a gas-tight solution for the surface of his specially developed battery terminals, which had previously been sourced from China for the Russian market and manufactured by hand in a laborious process, recalls Ralf Löschner, founder of Wenaroll Tools and Systems. Löschner recommended the development of a roller burnishing system, as cost-intensive processes such as grinding, reaming, lapping, honing and polishing can in most cases be replaced by roller burnishing technology. The resulting surface is characterized by a high contact ratio and improved tribological properties. Following this initial discussion, a firm German-Russian partnership has now developed.

The central component of the system is four parallel grippers on an aluminum frame construction.

Wenaroll from Solingen has been a leading supplier in the field of roller burnishing technology for metallic surfaces for more than 35 years. Its core technological competence is the development and manufacture of tools and machines. Wenaroll also offers the realization of application-specific system solutions. The company's long-standing international market and customer base includes renowned companies from the fields of commercial vehicles, construction machinery, aerospace technology, mechanical engineering and the automotive industry, among others.

The extensive development project, which resulted from the German-Russian cooperation, is an automated machine system for hardening the surface of Poland. The system consists of a frame with drive unit and substructure with various roller units, a gripper unit with four grippers, a control cabinet, a feeding and sorting unit and a control panel. This so-called battery pole smoothing machine makes it possible to compact the surface of battery poles made of lead alloys by smooth rolling.

Briefly explained, the process in the system then runs as follows: The battery poles enter the machine through the feed unit. The gripper unit transports the poles to the rolling units, where the actual processing takes place. For smooth rolling, the poles are clamped and rotated. The rolling units move together and the intended surfaces are consolidated with a defined force using the roller burnishing rollers. The roller burnishing process takes place at a maximum force of 255 Newtons and at a maximum speed of 400 revolutions per minute. The result is impressive: the poles are gas-tight and have a surface with a roughness depth Rz < 1 micrometer. In addition to the gas density, the Russian customer paid particular attention to the production speed of the machine: it had to be very high, so the processing time is a maximum of eight seconds per battery pole.

One of the central components of the system are the four parallel grippers, which are mounted on an aluminum frame construction. The customer had precise ideas regarding the grippers. Electric grippers with a single-cable solution were preferred. These should have the lowest possible gripping force so as not to damage the sensitive surface of the lead battery pole. The gripping process was not allowed to cause any defects in the gripped material. Another requirement was the possible use of long gripper jaws or gripper fingers. Depending on the item to be gripped, these should also be able to plunge deep into the device if necessary. High torques occurring in the gripper are optimally absorbed by the long jaw guides. This is made possible by a parallel offset arrangement of the gripper jaws, which also allows long guide lengths in a compact installation space. Furthermore, the grippers should be able to accurately grip different material thicknesses or sizes.

The grippers have a mechanical self-locking mechanism that prevents loss of the battery poles in the event of a power failure.

The development team headed by Ralf Löschner opted for the gripper specialist Zimmer Group. According to the company founder, the company from Rheinau in Baden not only had the required high quality and availability, but also "the best reputation in the region". Four models from the GEP2000 series (GEP2010IO-05-A) were selected specifically for this application: electrically driven small parts grippers that are easy to control and designed for assembly tasks and, above all, the handling of small parts. For these tasks, the series offers adjustable gripping forces between 40 and 500 newtons and jaw strokes between six and 16 millimetres.