| 摘要 |
<p>The purpose of the present invention is to provide a vacuum pump that can be assembled without the application of vacuum grease and that can achieve appropriate surface sealing. A tolerance and thermal deformation absorbing structure, in which is disposed an O-ring that is designed to be squeezed with a squeeze rate that leaves the proper degree of repelling force, is provided between a casing and a base. In the vacuum pump, when utilizing stators with a large height tolerance (press-formed stators, for example), or when the vacuum pump is an all-level type with a high number of levels of rotors and stators, if the squeeze rate of the O-ring disposed in the tolerance and thermal deformation absorbing structure exceeds the allowable deformation (distortion) with only one level, the disposed O-rings are provided in multiple levels and the O-ring squeeze rate per level is configured so that proper sealing by the O-ring is maintained. In this case, ring-shaped spacers are provided between the O-rings disposed in multiple levels to prevent the O-rings from shifting out of position in relation to one another.</p> |
