Patent ID: 6390790
Filing Date: 2002-05-21
Classification: F04B

Abstract:
In a vacuum pump of the type including a vacuum pump mechanism, said mechanism including a motor for driving said mechanism housed in a substantially enclosed motor chamber, a compression chamber which is expanded and contracted by operation of said motor, a first chamber, a one-way inlet valve for admitting one-way flow of a gas into said compression chamber from said first chamber, a second chamber and a one-way exhaust valve for exhausting compressed gas from said compression chamber into said second chamber, the improvement wherein said motor chamber has an inlet in communication with said second chamber through which said compressed gas from said second chamber flows into said motor chamber to cool said motor, and has an outlet through which said compressed gas from said second chamber is exhausted from said motor chamber, and further comprising a housing enclosing said motor chamber, wherein compressed gas from said motor chamber is exhausted into said housing so as to provide said gas in said motor chamber which is dense relative to the gas drawn into said first chamber, and wherein said housing has an exhaust port.