Introduction to Floating Face Seals

Floating face seals, also known as biconical seals, toric seals, mechanical face seals or lifetime seals, rely on two matched half-part assemblies for their operating principle. Each half contains a metal seal ring and a o-ring, and these elements work together to achieve an effective seal. One side of the sealing ring is precision ground to ensure a perfect fit with the opposite sealing ring face, while the o-ring is responsible for holding the two halves together for a reliable floating face seal.

Floating face seals, however, are not permanently durable. Although they are designed to cope with the extreme conditions faced by construction and mining equipment, they have a limited service life. For this reason, floating face seals should be replaced at the appropriate time during the life of the equipment. In order to prolong their service life, it is recommended that debris around the seals is regularly removed. If cleaning of the machine and chassis system is neglected, abrasive contaminants will gradually build up around the floating seals, resulting in much less effective sealing and a significantly shorter service life.

Once the floating face seals fail, leaks can occur behind the sprocket, causing gear oil to escape. This not only exposes the planetary side of the final drive to damage and corrosion, but also allows abrasive material to enter the interior of the drive. At the same time, dirt, sand, concrete and other impurities in the chassis system and around the final drive can intrude into the precision gears and bearings in the driving motor, mixing with the gear oil to form a sticky and odorous sludge. Instead of lubrication, this sludge can lead to overheating, wear, erosion and other problems, ultimately leading to complete failure of the final drive.

There are various reasons for the failure of floating face seals. On the one hand, over time, floating face seals may fail by exceeding their rated life and need to be replaced. On the other hand, floating face seals can be displaced by prolonged exposure to contaminants, with excessive debris accumulating on the outside of the seal, causing it to shift out of position. This process usually begins with damage to the O-ring, and as it weakens, the sealing surfaces can no longer fit tightly. Once this happens, debris can get further between the sealing surfaces, exacerbating the problem. Seal failure can be further exacerbated by contaminants mixing with gear oil to form a damaging sludge.

To prevent premature failure of floating face seals, it is recommended that the machine should be checking regularly. This simple maintenance measure will effectively minimise the damage caused by contaminants to the seals, thereby extending their service life and saving you significant maintenance costs. If you notice that you need to replenish the gear oil frequently, or that there is a gear oil leak behind the sprocket, this may be a sign that there is a problem with the seals, which should be replaced promptly. The sooner you address such leaks, the sooner you can avoid greater repair costs.