Patent ID: 9279426
Filing Date: 2016-03-08
CPC Classification: F04C,F16J

Claim Text:
1. A multi-stage vacuum pump comprising: two housing components with at least one of the two housing components comprising a plurality of cavities, the two housing components to be sealingly connected to one another thereby defining an array of chambers comprising a plurality of chambers defined between the two housing components such that each of the plurality of chambers is defined in part by a respective one of the plurality of cavities of one of the two housing components and in part by the other of the two housing components, the array of chambers extending longitudinally from an inlet region of the pump to an outlet region of the pump; sealing means, extending longitudinally along the array of chambers such that the sealing means is at a connection between the two housing components along each chamber of the array of chambers to prevent transfer of fluid in to and out of the vacuum pump at the connection between said two housing components; and an array of discrete, elongate channels, located between the sealing means and the array of chambers for protecting the sealing means from fluid passing through the chambers, each channel is at the connection between said two housing components and each channel being configured to receive a barrier fluid having a different pressure than a barrier fluid to be received by an adjacent channel and each channel extending longitudinally along fewer chambers of the array of chambers than the sealing means extends along.