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:
Feb. 24, 1987
Filed:
Jun. 07, 1985
Arnold O DeHart, Rochester, MI (US);
James D Symons, Southfield, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A combination vacuum pump, low friction bearing and seal assembly is provided in which a rotor relatively rotatable with respect to a stator has two sets of radially spaced, concentric spiral grooves. As the rotor rotates, one set of grooves forces sufficient ambient air between confronting surfaces of the rotor and stator to keep them axially spaced and provide a low friction bearing. Another set of grooves forces sufficient air from the vessel and through a one-way air exit to evacuate the vessel. A restriction created by the axially spaced confronting surfaces substantially prevents ambient air from moving radially inwardly to the evacuated vessel, as well as trapping the ambient air to maintain the axial spacing. Any ambient air passing through the restriction is dumped back to ambient through the same air exit, thereby keeping the evacuated vessel sealed.