Method and apparatus for preventing lubricant flow from a vacuum source to a vacuum chamber

An assembly comprising;

• a vacuum chamber (12) having a vacuum outlet duct (14) for connection to a vacuum source to establish a stream of gas flow from said vacuum chamber (12) through said outlet duct (14) to a vacuum source, said assembly further comprising electric field-producing means (22, 23, 24) for producing an electric field to subject the lubricant entering the vacuum outlet duct (14) from a vacuum source to the electric field to electrically charge the lubricant and electrically attract the lubricant back toward a vacuum source, said electric field-producing means including a pair of first (22, 23) and second (24) electrodes spaced from one another between said vacuum chamber (12) and a vacuum source and power means (26, 32) for establishing an electrical potential between said electrodes, said first electrode (22, 23) being positioned closer to said vacuum chamber (12) than said second electrode (24), said power means establishing a potential so that the lubricant is charged by said first electrode (22, 23) and is thereby attracted back to said second electrode (24), and a magnet (38) positioned and arranged to establish a magnetic field extending between said electrodes to urge the charged lubricant toward said second electrode.