APPARATUS HAVING EVACUATION SPACES AND A PUMPING ASSEMBLY

摘要

An apparatus has a high vacuum seal and at least one additional evacuative space as well as a pumping assembly for evacuating the vessel and space. The pumping assembly has a backing pump and a turbomolecular pump having a main section communicating with the vessel and with the backing pump. The turbomolecular pump has an auxiliary section communicating with the additional evacuative space and has a housing enclosing the main and auxiliary sections. The turbomolecular pump has first and second pump members disposed in the main and auxiliary sections respectively. The housing includes a wall intermediate the main and auxiliary sections for separating the sections in vacuum tight relation to each other. The turbomolecular pump has a rotor shaft which passes through the wall and connects the first pump member with the second pump member.