Experimental investigation and FEM analysis of resonance frequency behavior of three-dimensional, thin-walled spur gears with a power-circulating test rig

This paper is a fundamental study on resonance frequency behavior of three-dimensional, thin-walled spur gears from experimental tests and finite element analyses. Firstly, “power-circulating form” test rig is built for vibration tests of the thin-walled gears at the speed range 500–3000 rpm and then strain phase method is presented in this paper to identify the resonance mode shapes of the thin-walled gears when they are running in a complete resonance state. It is found that when wall thickness of the gear is very thin, vibrations of the thin-walled gear are the 2nd, the 3rd, the 4th order bending vibrations of the rim and the 2nd, the 3rd and the 4th bending vibrations of the web. When the wall thickness is increased, the 2nd, the 3rd and the 4th order bending vibrations of the web disappear and only the 2nd, the 3rd and the 4th order bending vibrations of the rim are remained. Effects of gear wall thickness, teeth mesh stiffness and assembly errors on resonance frequency behavior of the thin-walled gears are also investigated experimentally and peak speeds of the thin-walled gears are measured. It is found that there are several frequency components existing at the same peak speeds of the thin-walled gears.