A New Dynamical Test Bench for Multi-Axial Loading of Angle Grinders

Abstract

Automated testing with test benches plays a major role in the development of power tools such as angle grinders. Previous test benches for testing the drive train of an angle grinder replace the load from grinding a workpiece by dynamometer or servo motor in rotary direction and by linear motors in radial and axial direction. These can only apply forces up to 10 Hz and thus no speed-dependent force components. The aim of this paper is to develop a test bench for dynamic mechanical loading of the drive train of an angle grinder in the rotational, radial and axial axes up to 200 Hz, which corresponds to the maximum speed of an angle grinder. For this purpose, the modelling of the force application on the test bench and the resulting mechanical design is presented. In addition, the generation of test cases from measurement data of manual tests and the verification of the test bench are presented. Subsequently, a case study is presented to investigate the load pattern on the test bench with multi-axial load compared to pure torque loading on the same test bench and manual tests. It can be seen that the load pattern of the multi-axial load is qualitatively similar that of the load pattern from the manual test. Through using the developed test bench, it will be possible to investigate load patterns as well as wear or vibration of the drive train of an angle grinder.