Patents Represented by Attorney & Shuster Zalkind
  • Patent number: 4443169
    Abstract: A gear pump having an annular internal tooth gear and an external tooth gear eccentrically rotative therein is provided with a choke bore at the inlet side of the pump and a series of outlet pressure bores. The outlet bores are valved with individual check valves so as to pass pressure oil from the pressure pockets between the relatively moving gear teeth which pockets diminish in volume at the outlet side of the pump as the teeth move therepast and the pressure pockets discharge into the outlet bores. Where a pocket is insufficiently filled to effect the pressure needed for opening the first valves moved pass by the pressure pockets, the pressure increases with continued rotation as pocket volume decreases. The increase in pressure in the pockets with volume reduction ultimately opens an outlet bore valve to effect discharge to a common high pressure chamber.
    Type: Grant
    Filed: January 28, 1981
    Date of Patent: April 17, 1984
    Assignee: Zahnradfabrik Friedrichshafen, AG
    Inventor: Johann Merz