The software landscape in the field of gearbox development, simulation, and production is extremely diverse today. Although these programs perform different tasks, the data they use is largely identical. However, no industry-wide standard has been established for the exchange of gearbox data. This leads to high-cost, high-maintenance custom solutions and duplication of work that can be avoided.

“The goal is to be able to efficiently and effectively use different systems with their own computational focuses, such as Bearinx, SIMPACK, and FVA Workbench,“ said Dr. Heinrich Bolz, head of calculation and simulation in gearbox development for SEW-Eurodrive.

FVA, the German Research Institute for Drive Technology, is committed to the goal of developing an industry-wide standard for the exchange of gearbox data. The interface will be developed in close cooperation with industry and research under the name REXS (Reusable Engineering EXchange Standard).

REXS defines an industry-wide uniform modelling and nomenclature for the gearbox and its components based on the detailed terminology of 25 of FVA's project committees. With many years of experience and broad roots in industry and research, FVA is in a unique position to develop an industry-wide standard in this area.

For FVA partners SEW Eurodrive and Schaeffler, the focus is primarily on the exchange of gearbox data related to bearing calculation. However, instead of developing another specialized solution, both companies became involved in the FVA “Standardization of Gearbox Modelling,” research project, thus laying the foundation for the interface.

Their many years of experience with gearbox software will ensure that the developed concept is applicable for the industrial environment.

“For this purpose, we made a deliberate decision to develop a common standard with FVA, as this approach holds tremendous potential for the future,“ said Bolz.

The first practical implementation of the REXS interface was the exchange of data between the FVA Workbench, Schaeffler's Bearinx, and SEW's Wesilab software.

The advantages of the REXS interface are clear: it reduces errors during the exchange of data and minimizes the effort required for communication between different programs. Development of a new interface is very labor intensive, therefore, the barriers to creating new links between existing software tools are high. A uniform interface can be used to efficiently implement such links, and to accelerate and improve the product development cycle.

“With REXS, gearbox data can be transferred quickly and reliably. Thus, the interface helps us to optimize our innovation processes," stated Bolz.

“We can greatly reduce the effort for the technical coupling of CAD software tools, and at the same time simplify the IT architecture,” added Stephan Evert, leader of CAE application development for research and development processes, methods, and tools at Schaeffler.

n REXS, the components of a gearbox are defined based on common parameters. The REXS specification includes everything necessary to define a gearbox model. Essentially, this includes the machine elements, their attributes, and the relations which are used to define the relationships between machine elements. The simple and generic structure of REXS makes it possible to depict individual components, assemblies, and complex gearbox structures.

The interface has an open architecture, so companies can define their own extensions without affecting the standard. Thus, the interface is suitable for exchanging data between standard programs as well for internal use with custom software solutions.

The first version of the REXS interface was released at the annual FVA Information Conference in November 2017. It is freely available under Creative Commons License (CC-BY-SA) at www.rexs.info.

Anyone who is interested can learn more about the interface as well as how they can contribute to its future development. Schaeffler and FVA demonstrated the simple transfer of data between their Bearinx and FVA Workbench software packages using the REXS 1.0 interface live at their stand at the FVA Information Conference.

“REXS defines a very simple, extensible data structure that was created from its conception as a standard to be distributed via free licensing,” Evert said. 

Although the current version of the interface is focused on the definition of gearboxes for calculation programs, the possibilities for future development are broad. According to the motto "If you want to achieve great things, you have to set high goals," FVA's vision for REXS is to develop an interface that can be used for all CAE powertrain applications.

“REXS is a real step toward new business models based on digital services, and can be used as a standardized data container for digital twins,” said Evert.

The FVA Workbench is a platform in which new concepts for the further development of REXS are already being implemented and tested for practical suitability.

From version 5.0, the FVA Workbench will always support the latest version of the REXS interface. This will make an important contribution to the efficient exchange of data and provide users with reference software for the implementation of the interface.

”In order to take advantage of digitization, it is essential that data can be exchanged beyond system boundaries. Proprietary data formats do not help, as they increase complexity in the digital world,” said Norbert Haefke, managing director of FVA GmbH. “That is why we see the FVA Workbench not just as a calculation platform for the community, but also as a common data hub and enabler for digitization in drive technology.”