| 摘要 |
PURPOSE:To prevent seizure by providing a lubricating oil-sucking hole to be drilled in a main bearing and a subbearing while a rotary shaft to be formed hollow and a spiral groove in the rotary shaft in its subbearing and main bearing sides. CONSTITUTION:A subbearing 2 provides a lubricating oil-sucking hole 10 to be drilled, and hollow forming a rotary shaft 4, delivered gas to a delivery chamber 3 is guided to space 6 in an end part of an electric drive element 5 through this hollow part 4a. Spiral grooves 11, 13 are provided in the rotary shaft 4 in its sides of the subbearing 2 and a main bearing 12. Thus eliminating the necessity for providing a delivery gas communicating pipe in the outside of a compressor as in the past, while by pumping action of the spiral groove 11 in the side of the subbearing 2, lubricating oil can be discharged. Further thrust force in the axial direction, generated by the pumping action, is negated by the spiral groove 13, and the necessity for a thrust bearing is eliminated. Accordingly, seizure can be prevented with no generation of shortage of the lubricating oil. |
