Part of #Stability of a Three-Axis Power Transmission System# :
Publishing year : 2012
Conference : Second International Acoustic and Vibration Conferences
Number of pages : 8
Abstract: Shaft system is one of the power transmission systems, which has many applications due to high rotational speed and low weight. The system includes some shafts that are based on the application of the system can be non-aligned. A common way to link the non-aligned shafts is to use a universal joint. This joint has many advantages but transforming a constant input speed into a periodically fluctuating one. As a result, the system is parametrically excited and hasdynamic instability (or resonance) conditions. Therefore, introduces several special unstable regions into the system. In this work, the dynamic stability of a three-axis power transmission system is investigated. This system consists of three torsionally elastic shafts with different rotary axes. The systemability has been investigated by means of a three-degree-of-freedom model in a spatial coordinate (three-dimensional). Each shaft carries a rigid disk at one end and has been connected through two universal joints. Equations of motion for the system are derived andlinearized. The differential equations consist of a set of Mathieu-Hill equations. Their stability is analyzed using a reliable, accurate numerical technique called "monodromymatrix" method. The validation of the model is obtained by comparing the areas of nstability with the natural frequencies of the system or their combinations. Also, the harmonic, sub-harmonic, sum combination and the difference type combination are calculated for parametric resonance regions corresponding to different vibration modes. Finally, dynamic stability regions have been shown on system parameters such as rotational velocity, misalignment angle's of the shaft axis, shaft stiffness and rigidity. It has been observed that increasing the inertia ratio of the disks and decreasing universal joint leads to more stability.