Drive axle assembly with gear mesh lubrication systems for lubricating gear mesh and/or differential bearings

A method for operating an axle assembly comprising:

• providing an axle housing having an internal cavity, a portion of the internal cavity forming a first sump;
• mounting a pinion in the axle housing, the pinion having a plurality of teeth;
• mounting a differential assembly in the axle housing, the differential assembly including a ring gear and a differential, the ring gear having a plurality of teeth that are meshingly engaged to the teeth of the pinion;
• rotating the ring gear in a predetermined rotational direction through a lubricant in the first sump to cause the lubricant in the first sump to cling to the ring gear;
• collecting a portion of the lubricant that has clung to the ring gear in a second sump that is elevated above the first sump;
• draining a first portion of the lubricant in the second sump directly onto at least one of the teeth of the pinion and the teeth of the ring gear;
• and
• draining a second portion of the lubricant in the second sump to a bearing set that supports the pinion for rotation within the axle housing.

An axle assembly comprising:

• an axle housing having an internal cavity, a portion of the internal cavity forming a first sump;
• a ring gear mounted in the internal cavity for rotation about a first axis, the ring gear being rotatable through the first sump to cause a lubricant in the first sump to cling to the ring gear;
• a differential coupled to the ring gear for rotation therewith about the first axis;
• and
• a pinion mounted in the internal cavity of the axle housing for rotation about a second axis that is perpendicular to the first axis, the pinion including a plurality of teeth that are meshingly engaged to the ring gear;
• and
• an auxiliary collecting means for collecting a portion of the lubricant that has clung to the ring gear as it rotates in a predetermined rotational direction through the first sump, the auxiliary collecting means having a second sump and a drain, the second sump being disposed in the internal cavity and being discrete from the first sump, the drain being configured to at least partly drain the second sump directly onto the teeth of the pinion;
• wherein the axle housing has a wall member that at least partly forms the second sump and at least a portion of an exterior surface of the axle housing;
• wherein the drain includes a tubular member that is coupled to the wall member;
• wherein the auxiliary collecting means includes a scraper that is configured to direct the portion of the lubricant that has clung to the ring gear from a surface of the ring gear into the second sump;
• wherein the scraper contacts a surface of the ring gear as it rotates;
• wherein the scraper is at least partly formed of a resilient material;
• and
• wherein the drain is also configured to dispense a portion of the lubricant in the second sump to a bearing set that supports the pinion for rotation within the axle housing.

A method for operating an axle assembly comprising:

• providing an axle housing having an internal cavity, a portion of the internal cavity forming a first sump;
• mounting a pinion in the axle housing, the pinion having a plurality of teeth;
• mounting a differential assembly in the axle housing, the differential assembly including a ring gear and a differential, the ring gear having a plurality of teeth that are meshingly engaged to the teeth of the pinion;
• rotating the ring gear in a predetermined rotational direction through a lubricant in the first sump to cause the lubricant in the first sump to cling to the ring gear;
• and
• contacting a surface of the ring gear with a scraper to scrape a portion of the lubricant that has clung to the ring gear and dispensing the scraped portion of the lubricant directly onto at least one of the teeth of the pinion and the teeth of the ring gear.