Abstract: An improved capacitance manometer includes a thin, electrically conductive diaphragm fixedly mounted to a housing. The diaphragm separates a first chamber that is subjected to a reference pressure from a second chamber that is subjected to a pressure that is to be measured relative to the reference pressure. The diaphragm flexes in response to a pressure differential between the two chambers. The diaphragm comprises one electrode of a variable capacitor. A second electrode of the variable capacitor is provided by a fixed electrically conductive area mounted on a ceramic disc or other fixed electrode support. The ceramic disc is mounted within the housing so that the electrically conductive area on the ceramic disc is proximate to and spaced apart from the diaphragm in generally parallel relationship to the diaphragm when the diaphragm is in a substantially relaxed condition (i.e., not flexed by a pressure differential).

Abstract: A single-ended turbomolecular vacuum pump operable in the free molecular flow pressure range having an improved bearing assembly located between the motor and the pump rotor discs is disclosed. The improved bearing assembly which is of the "plain" or "sleeve" liquid lubricated type with the bearing surfaces has a relatively high ratio of journal diameter to bearing axial length and includes lubricant ports radially disposed about both the centers of the bearing and the journal. The improved bearing assembly is characterized by improved heat transmission capabilities, high tolerance for misalignment, long life and significant reduction of pump vibration.

Abstract: A single ended turbomolecular vacuum pump operable in the free molecular flow pressure range having an improved bearing assembly between the motor rotor and the pump rotor discs is disclosed. The improved bearing assembly which is of the "plain" or "sleeve" liquid lubricated type has a relatively high ratio of journal diameter to bearing axial length. The improved bearing assembly is characterized by improved heat transmission capabilities, high tolerance for misalignment and long life.