The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 28, 2002
Filed:
Jun. 21, 2000
Marsbed Hablanian, Wellesley, MA (US);
Varian, Inc., Palo Alto, CA (US);
Abstract
Vacuum pumping apparatus includes a rotor, a motor for rotating the rotor about an axis of rotation, a stator mounted in proximity to the rotor and a housing enclosing the rotor and the stator. The stator includes at least one spiral channel having an open side facing the rotor. The housing defines an inlet in fluid communication with the inner portion of the spiral channel. Gas is pumped outwardly with respect to the axis of rotation through the spiral channel as the motor rotates the rotor. The stator may include two or more spiral channels coupled in parallel. The spiral channels may decrease in cross-sectional area from larger at the inner portion of the stator to smaller at the outer portion of the stator. The vacuum pumping apparatus may include a second vacuum pumping stage on a second side of the rotor and a series connection between the first and second vacuum pumping stages. The second vacuum pumping stage may have a variety of different configurations.