Patent ID: RE42408

Claim:
An internal combustion engine oil pump, comprising: a pump body, including a first gear chamber and a second gear chamber; a cover mounted to the pump body; a drive shaft extending into the first gear chamber and the second gear chamber; a first set of intermeshing involute spur gears in the first gear chamber, wherein each of the first set of gears has nine or fewer teeth, wherein each tooth has an involute profile ; , and wherein one of the first set of gears is driven by the drive shaft; and a second set of intermeshing involute spur gears in the second gear chamber, wherein one of the second set of gears is driven by the drive shaft ; and , wherein the a ratio of the a depth of the first set of gears to the a depth of the second set of gears is about 11/16 ; wherein at least one of the gears in the first and second sets has an orifice for receiving the drive shaft; and a snap ring retaining the drive shaft, the snap ring being recessed in the orifice to eliminate leakage around the drive shaft .