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:
Sep. 26, 2000
Filed:
Mar. 13, 1998
James R McBurnett, Greer, SC (US);
William D McMillan, Simpsonville, SC (US);
Dana Corporation, Toledo, OH (US);
Abstract
A positive displacement gear pump useful for pumping hydraulic fluid includes a drive gear and an idler gear. In a first embodiment, the drive gear has symmetrical teeth, whereas the idler gear has asymmetrical teeth. The asymmetrical teeth of the idler gear include working surfaces which have a profile corresponding to the profile of the working and non-working surfaces of the drive gear, but have a non-working surface which has been relieved so as to be substantially flat. Consequently, in the zone of the pump where the gears mesh, a large backlash is created which substantially prevents bubble formation. In a second embodiment, the drive gear, as well as the idler gear, have non-contact surfaces which are substantially flat to create even a larger backlash for relieving cavitation when the teeth are made wider in the axial direction. By preventing bubble formation, cavitation which occurs at high pump speeds is substantially eliminated, thus avoiding pump damage which results from cavitation.