MARS – Methodology for the practical design of the rail-wheel system for stacker cranes

Stacker Cranes/Storage and retrieval machines (SRMs) are an integral part of modern logistics concepts. Today, devices that run on a rail are predominantly used. As a result of the increasing handling performance, the load on the SRM rail-wheel system has increased significantly in recent years, so that dynamic loads are increasingly reaching limits that cannot be covered by current design methods.

So far, the design of the rail-wheel system (metal wheel on metal rail) has been analogous to the design of crane rails according to DIN 15070. In practice, however, damage to the rail-wheel system of RBG occurs time and again despite the design conforming to standards. This can be attributed, among other things, to various methodological weaknesses of DIN 15070. These include in particular unrealistic contact conditions as well as insufficient adaptation to the operating conditions of SRM.

With DIN EN 13001-3-3, a new standardized calculation approach was created. Although it is also primarily designed for the design of the rail-wheel system of cranes, a large number of the weaknesses of DIN 15070 with regard to SRM have been eliminated. It can therefore be assumed that the application of DIN EN 13001-3-3 will lead to a more reliable design compared to DIN 15070. When applying DIN EN 13001-3-3, however, it should be noted that both the complete load spectrum for wheels and rails and the total number of rolling contacts must be known. As a result, the use of DIN EN 13001-3-3 is currently not applicable in practice for the design of the SRM rail-wheel system.

The aim of this research project is the development of a design methodology which combines the methodological advantages of DIN EN 13001-3-3 with an applicability similar to DIN 15070 and which is characterised by high reliability and economic efficiency as well as practical suitability.

It is necessary to design the methodology in such a way that all influences which are not known at the time of design are derived from known parameters. In particular, the load spectrum and the total number of rolling contacts between wheel and rail must be known.

Within the scope of the research project described, the gap between the theoretical design according to the standard and the practical applicability at the design time is closed. For this purpose, the user is provided with a procedure with which he can determine the load collectives and the number of rollovers on the basis of known parameters. If these parameters are known, the verification of the rail-wheel system according to DIN EN 13001-3-3 can be carried out simply and practically.

In order to achieve this, at the beginning of the research project all system parameters will be identified which are expected to influence the loads and rollover numbers. These include, for example, the properties of the SRM, the bearing configuration and the type of bearing task. Subsequently, a multi-body simulation is used to analyse a large number of parameter sets and to simulate the loads and rollover figures that occur. Thus, all quantities required for the checks according to DIN EN 13001-3-3 are known. In addition, correlations between the original design parameters (input variables) and the loads or rolling contacts (output variables) are identified and statistically verified. This results in a direct correlation between known input variables and the output variables. If these correlations are known, it can be checked for SRM systems with any configuration whether they meet the design requirements according to DIN EN 13001-3-3 and whether a safe design can be assumed. A special simulative investigation of each new SRM system is no longer necessary. The correlations determined are implemented in a software demonstrator in order to guarantee a design methodology that is as user-friendly as possible.

The resulting design procedure and the associated software demonstrator combine the high practical suitability of the design according to DIN 15070 with the consistent consideration of all influences from DIN EN 13001-3-3 and thus lead to a reliable design of the rail-wheel system.

  • Gebhardt Fördertechnik GmbH
  • LTW Intralogistics GmbH
  • MIAS Maschinenbau, Industrieanlagen & Service GmbH
  • MLOG Logistics GmbH
  • TGW Mechanics GmbH
  • viastore SYSTEMS GmbH

This research project is carried out on behalf of the Forschungsgemeinschaft Intralogistik/Fördertechnik und Logistiksysteme e.V. (Research Association for Intralogistics/Promotional Engineering and Logistics Systems). (FG IFL) and is funded by the Federal Ministry of Economics and Technology via the "Otto von Guericke" e.V. working group of industrial research associations. (AiF).