Abstract: A seal assembly disposed on a central longitudinal axis thereof which comprises a pair of annular rigid seal members and a pair of elastomeric retaining members. Each of the annular rigid seal members has a first seal surface, an annular groove and a second seal surface in sequence from the top.

Abstract: A seal for a joint subjected to oscillatory motion has a W-shaped seal ring which encompasses a backup ring partially. The W-shaped seal ring comprises a driving flange, a sealing flange and an intermediate hinge section connecting the two flanges.The backup ring is adapted to be fitted in the seal ring to force the driving flange into an interference fit with the counterbore walls so as to cause the driving torque to be applied through the seal ring. The seal ring is made of a tough abrasion-resistant material, while the backup ring is made of elastomeric material having excellent resiliency characteristics over a wide range of operating temperatures.The load exerted on the seal flange face is the sum of the compression forces of the backup ring and the seal ring and an internal pressure developed in the enclosed space.

Abstract: A two-piece master track link for connecting an endless track which is parted into two link parts along an approximately diagonal juncture defined by respective opposite mating surfaces of the pieces. Each of the two parts has a cavity corresponding to each other to form a substantially cylindrical hollow space where a traction and thrust bearing member is tightly fitted. Shoe bolts extend from the outside of a track shoe to one of the link parts through the other part so that both the link parts are fixedly secured to each other together with the track shoe. Thus, the assembly and disassembly of the endless track is simplified.