Seal assembly with dual density powder metal seat member

摘要

A dual density powder metal mechanical face seal seat is provided including a hub portion integrally formed as a unitary piece with a seat portion. The face seal seat is formed of powder metal that has a higher density in the hub portion than in the seat portion. The higher density hub portion provides the seal seat with greater strength characteristics where the seal seat mounts to a shaft. The lower density seat portion allows greater amounts of lubrication to be impregnated in the seal seat portion where it is needed while a smaller amount of lubrication is provided in the hub portion where it is not needed. The higher density hub portion has a higher coefficient of thermal conductivity to draw heat away from the seal seat portion. The smaller pores in the hub portion provide a capillary effect to cause lubrication impregnated in the seal seat to be sucked back into the pores when the seal seat is not rotating. The duel density powder metal also eliminates the necessity to mask portions of the seal seat while the seal seat is being impregnated with lubrication since the dual density regions automatically control the impregnation amount in the different regions.