Patent attributes
A gear pump for an axle assembly circulates lubricating fluid from a reservoir to a fluid cooler external to the axle assembly. The gear pump includes a first housing section and a second housing section and a center section located between the first and second housing sections. An input gear mounted on an input shaft is engaged with a reduction gear, which are located in a first housing section. Two pumping gears are located in the second housing section. The center section serves as a wall and separates the first housing section from the second housing section. The gear ratio between the input gear and the reduction gear is such that the pumping gears rotate at a speed between at about 47% and at about 75% of the speed of the input shaft.