Study Of Shock Resistance For Marine Gear Box Oil Pump Group

The marine gear box oil pump group is one of the important accessory devices of the gear box and has great relationship to the normal operation of the transmission system. Its shock resistance and impact safety will directly affect the normal navigation of ships. Under the impact environment, the marine gear box oil pump group standing the work pressure and the impact force caused by the underwater non-contact explosion may lead to the damage and failure of gear box oil pump components. So it’s of great necessity to adopt the numerical method to study the shock resistance of the marine gear box oil pump group, which can provide reference for the design of typical marine mechanical equipment.Firstly, the three-dimensional geometrical model is built according to the design drawings. By some simplifications of model according to the common practice in engineering,the finite element model is obtained further. Through the modal analysis, the natural frequencies and modes of vibration are extracted, and the rationality and feasibility of the FEM model is validated, which contributes to the reasonable design of the pump group structure and finding the potential weak parts.The dynamic response of the marine gear box oil pump group is investigated in both the time and frequency domain by the dynamic design analysis method (DDAM) and the real-time simulation method. The analysis is conducted from the transverse, longitudinal and vertical direction respectively. For the dynamic design analysis method (DDAM), the shock response spectrums along different directions are designed according to the military standard,and they are treated as boundary conditions to conduct the impact response analysis. From the analysis, the stress distribution of the marine gear box oil pump group is shown and the weak parts are also detected. In the real-time simulation method, the shock spectrum is equivalently transformed to the plus-minus triangular shock response spectrum according to the German military standard. The limit load of the oil pump group under the impact load with different pulse widths and peaks is determined, and the dangerous areas are also determined. By comparing the two results, the dynamic response characteristics of the oil pump group in the non-integration system are presented.Finally, to better simulate the real shock environment of the marine equipment, the coupling integration system of the gear box oil pump group and the hull is modeled based on the flexible system coupling law. Its integrated shock response analysis of underwater explosion is conducted to study the stress distribution characteristics of the oil pump group.In addition, the effects of the hull flexible structure on the impact response are investigated by comparing to the results of the non-integrated analysis in time domain. Based on the above analysis, the dangerous areas of the gear box oil pump group are determined and can be used as the reference to the optimization design to improve the shock resistance performance of ship equipment.