The aim of the presented study was to perform a global sensitivity analysis of various design parameters affecting the lost motion of the harmonic drive. A detailed virtual model of a harmonic drive was developed, including the wave generator, the flexible ball bearing, the flexible spline and the circular spline. Finite element analyses were performed to observe which parameter from the harmonic drive geometry parameter group affects the lost motion value most. The analyses were carried out using 4% of the rated harmonic drive output torque by the locked wave generator and fixed circular spline according the requirements for the high accuracy harmonic drive units. The described approach was applied to two harmonic drive units with the same ratio, but various dimensions and rated power were used to generalize and interpret the global sensitivity analysis results properly. The most important variable was for both harmonic drives the offset from the nominal tooth shape.

This paper presents the research of modal characteristics of the bolted housing. The aim of the research was to find out the impact of the methodology of the solution of bolted joints on modal characteristics of the bolted housing of the...

The safety of machinery is a very important aspect for its correct functioning in the conditions of modern production or assembly. According to the standards, manufacturers of special-purpose machines and devices are obliged to provide their equipment with a certificate of conformity (CE). This article describes the concerns of insufficient safety of a device. Insufficient coverage of part of the line meant that the certification did not take place, and the safety requirements were not met. The TRIZ method was used to resolve this technical discrepancy, providing designers with "instructions" on how to proceed, solve complex problems at the level of discrepancies and create solutions. By agreement of the designers, a solution that was not economically and implementation-intensive was created. All doors and windows within the fencing have been reinforced, thus achieving a greater degree of security. The resulting solution was subjected to simulations in the Ansys Workbench program, and the FEM analysis led to certain conclusions. The results were then moved to the structural engineer to assess the solution, who then approved the solution and successful certification of part of the device, respectively, in the assembly line.