Excavator Seat Vibration Research Based On Operational Transfer Path Analysis

With the rapid development of the excavator industry and society’s growing awareness of environmental protection, GB and other laws®ulations on the requirements of noise and vibration limits have been becoming more and more stringent, also users requirements of the excavator NVH performance continue increasing. The seat vibration as the main part of the excavator NVH performance plays an important role in the driver’s safety, working efficiency and physical&mental health. In order to control the excavator seat vibration, improve the excavator NVH performance, and strengthen the excavator industry’s competitiveness of our country, it is great important to research the excavator vibration transfer path and the vibration contribution of each path.Based on the project "The vibration and noise control research of XX model excavator", vibration operational transfer path analysis from the excavator engine to the cab seat was researched in this paper, in the background of excavator vibration and noise reduction. In this paper, the transmissibility functions of vibration from the engine’s four mounting positions to seat of the cab and three working status’ vibration contributions of each path were calculated, in order to analyze the problems existing in the excavator seat vibration and propose improvements.For the problems in the application of researching excavator seat vibration with operational transfer path analysis, specific improved methods were proposed. And the application scheme was summarized in using the improved operational transfer path analysis. Then the operational transfer path analysis model of vibration from the engine to the seat was designed, and the corresponding experiment was performed. Finally the model was solved with the test data, and the vibration transmission from the engine to the seat was researched with the solved model.The vibration components of large amplitude were identified by spectral analysis, and then the vibration contributions of each path were calculated especially at the vibration components’ frequencies of large amplitude. With the vibration contribution vector illustration and effective vibration contribution bar graphs, the path of greater contribution was identified. The methods to reduce seat vibration were proposed by analyzing the model inputs and transmissibility functions.In the three engine states of lowest speed, rated speed, and the maximum speed, the vibration transmission from engine to the seat was researched. And analysis results are as follows:the seat vibration component of the largest amplitude was at the engine firing frequency; the reason why the seat vibration component at the engine firing frequency was of the largest amplitude was that, the amplitude of the engine vibration component at the frequency after the rubber dampers at left front and right front was still of large amplitude. Therefore, in order to improve the excavator seat vibration performance, the vibration damping performance of left front and right front rubber dampers should be improved.