Optimizing the Architecture of Hoists by Simulation
The normative DIN EN 14492-2:2010-05 „Cranes - Power driven winches and hoists“ was released with some changes in May 2010 after a revision. The revision defines additional requirements for the availability of an emergency stop operation. In addition, when transporting hot molten masses it is required that the design of the hoist must be fail-safe which means that even in case of a component failure in the powertrain a fall down of the load must be prevented under any circumstances. According to the standard this can be achieved via a redundant design of the hoist or an emergency stop brake along with a redundant rope or chain drive.
Out of the new requirements the necessity to verify the compliance of existing hoisting units with the new emergency requirements arose. Especially the expected torsional stress on the components during an emergency stop needed to be checked.
The paper recalls the example of a casting crane how the expected torques and forces during an emergency stop have been calculated using a simulation model of the hoist. It further shows how simulation helped to select a suitable design and the dimensioning of its components in the days when the norm was changed. The design changes that have been made due to the findings are nowadays common practice at the Kranbau Köthen GmbH.