Vacuum pump with reduced seal requirements

A vacuum pump 10 comprising a hermetically sealed enclosure 40, a core pump assembly with two stator halves 12, 14 located within the enclosure, and an inert purge gas inlet 70 fluidly connected to the enclosure for supplying inert purge gas (e.g. nitrogen, argon) to an interior of the enclosure surrounding the core pump assembly such that a positive pressure is applied to the core pump assembly that reduces leakage of process gas, thus removing the need for elastomer seals in the core pump assembly. There may be thermal spacers 60 made of ceramic material between the core and the enclosure. The stator halves may comprise purge gas leakage channels (fig.2, 100) fluidly connected to the pump chambers (fig.2, 80). The vacuum pump may comprise a motor 20, an end cover 30, a gear cover 22 located outside the enclosure and a pair of head plates 18.