SEAL STRUCTURE AND FUNCTION The structure of the seal is similar to that of seals used in idlers and rollers of undercarriage. It consist of a part which seals oil in and keeps dirt and sand out, and load ring which impose a thrust to the said part. The load ring is set in place in a crushed condition. Its resilience pushes the sealing portion in the direction of thrust, exerting the proper surface pressure on the sliding surface with the bushing. The thrust is also given in the radial direction of the link counterbore, preventing oil from leaking from the bores.
The spacer is set inside the seal to protect it from overload and keep the direction of the seal at proper level while the machine is traveling. 1) F5 seal Adopted on large size bulldozer Link Load ring Bushing Seal ring Spacer Pin (Free load) (Assembled) 2) F3 seal 3) W7 seal Adopted on middle size bulldozer Adopted on small size bulldozer (Assembled) (Assembled) - 4 -