| 摘要 |
PURPOSE:To reduce the vibration of a closed case by forming a cylindrical fitting part and a circular section part having a smaller diameter than that of said fitting part on the cover part on the compressing element side of a closed case and making the axes of both parts eccentric. CONSTITUTION:A fitting part 25 with a cylindrical form and a vicinity part 26 with a circular section and having a smaller diameter and a more upwardly sided axis than those of the fitting part, are formed on the cover part 23 on the compressing element side of a closed case 17. And, the part between the fitting part 25 and the vicinity part 26 is formed into a taper part 27 which expands toward the fitting part 25 side. Due to such structure, the taper part 27 has the largest angle on its lower part, being made strong against deformation in the radial direction. Thereby, the rigidity of the bottom part 17a of the cylindrical part 18 of the closed case 17 is improved, and natural frequency is increased reducing noise. |
