Back to results
US 6,123,533 AGranted
Cavitation-free gear pump
AssigneeDana Corporation
InventorsJames R. McBurnett, William D. McMillan
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeDana Corporation
InventorsJames R. McBurnett, William D. McMillan
Estimating the term…
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.
In a gear pump for pumping liquids having dissolved air therein with meshed gears from an input to an output, the improvement comprising:
A gear pump for pumping liquids having dissolved air, wherein the gear pump comprises a drive gear and an idler gear within a housing having surfaces, wherein the drive gear has teeth which are symmetrical and have working and non-working idler surfaces with arcuate profiles and wherein the idler gear has asymmetrical teeth with working surfaces corresponding in shape to the working surfaces of the drive gear and non-working surfaces which are relieved, as compared to both the working and non-working surfaces of the drive gear for preventing damage to the surfaces by increasing backlash so that formation of air bubbles is precluded and localized pressure spikes which cause pitting are avoided.
Dependencies are inferred from the claim text.