涡轮增压器主要部件结构特性及改进研究

机车柴油机用废气涡轮增压器浮动轴承烧灼、转子积碳固死及喷嘴环热裂、叶片变形等是影响增压器可靠运用的多发故障。通过对浮动轴承浮动套实际转速测量及轴承内外间隙调整试验,指出了浮动轴承烧损的主要原因是浮动套内间隙的增大,提出了以滑动轴承代替浮动轴承的设计方案;通过增压器油封密封机理分析及不同油封对回油腔压力变化影响的试验对比分析,设计了涨圈加反螺纹组合式油封,筛选出了最佳组合方式;喷嘴环用材料力学性能及喷嘴环结构热疲劳力学试验结果表明,采用以2Cr13为材质、不带外环的插嵌式喷嘴环结构,既可消除喷嘴环热裂故障,其插嵌式单片精铸叶片又可保证静叶型线准确及叶片表面光洁度。改进后的部件结构有效提高了增压器整机使用的可靠性。

Structure Characteristics and Improvement of Main Components of Turbo-supercharger

The faults that often affect the reliability of the supercharger are the cauterization of the floating (bearing) of the gas turbo supercharger, the carbonization of the rotor and getting stuck, heat cracking of the (nozzle) ring and the deformation of the blade. Through the measurement of the actual rpm of the floating sleeve of the floating bearing and the adjustment of the inside and outside clearances of the bearing, the paper finds that the main reason causing the burns of the bearing is the increase of the inside clearance of the floating sleeve and therefore proposes to use friction bearing to replace the floating bearing. Through the analysis of the sealing mechanism of the supercharger oil seals and the test and comparison of the influence of different oil seals on the pressure in the back oil chamber, the paper designs a seal that uses a expansion ring with reverse threads, and selects a optimum combination. The test result of the mechanical performance of the nozzle material and the heat fatigue test of the nozzle structure shows that when 2Cr13 material is used and the imbedded nozzle structure without outer ring adopted, the heat crack of the nozzle can be rooted out and the imbedded single casting blade can ensure the accuracy of the blade profile and the smooth finish of the blade. The improved structure of the component has effectively enhanced the reliability of the whole unit of the supercharger.