Air seeder meter with air purge

A method of reducing damage to bearings in an air seeder meter, the meter operative to dispense agricultural products into a product conduit carrying a product air stream at a product air pressure, the method comprising:

• providing a sealed tank operative to contain the agricultural products, wherein the sealed tank is pressurized to a tank pressure that is substantially equal to the product air pressure;
• mounting a meter roller in a housing below the sealed tank;
• extending a shaft through a center of the roller, and providing a drive operative to rotate the shaft and the meter roller;
• providing clearance spaces on each side of the meter roller to allow the meter roller to rotate in the housing;
• providing right and left bearings mounting the shaft to the housing;
• providing right and left seals mounted to the shaft and to the housing between the right and left bearings and the corresponding right and left sides of the meter roller, wherein the seals are operative to substantially seal the corresponding right and left bearings from the meter roller;
• providing right and left chambers in the housing between the right and left seals and corresponding right and left sides of the meter roller;
• conducting a purging air stream into each of the right and left chambers, wherein the purging air stream is at a purging air pressure that is greater than the product air pressure such that the purging air stream flows from each of the right and left chambers through the clearance spaces.