摘要 : Structurally , giving priority to ultra-small swing radius on machines used typically in urban civil engineering where there is the greatest demand for low noise level makes it extremely difficult to maintain low noise levels. Res... 展开 Structurally , giving priority to ultra-small swing radius on machines used typically in urban civil engineering where there is the greatest demand for low noise level makes it extremely difficult to maintain low noise levels. Research anddevelopment was carried out over the short period of only one year on ultra-small swing radius hydraulic excavators resulting in an ultra-low-noise machine with an extremely large reduction of 10 dB(A) from the current machine.The background to the research, the steps taken to realize this concept, and the advantages and effect of the structure are described in this report. 收起