Abstract: A piston includes a circumferential groove having a dynamic split seal ring having a flat axially facing surface, a static seal ring having a flat axially facing surface abutting the flat surface of the dynamic seal ring, and a spring mounted within the groove. The spring exerts an axial force on the static seal ring that serves to distribute the axial load with a static seal over the dynamic split seal, thereby preventing shuttling of the split seal within the groove and restricting the leak path of the seal. Preferably, the static seal ring is a polymer and can be an L-ring, a load ring with a flange that abuts the piston body, or flanged designs. In addition, a load ring can be fitted between the L-ring and the spring. The split seal ring has at least one radial spring mounted within the seal ring to create a radial force on the split seal ring. The piston can also include a sleeve that mounts to the piston body, the sleeve forming a wall of the groove.

Abstract: A piston includes a circumferential groove having a seal ring and spring mounted within the groove. The spring exerts an axial force on the seal ring thereby preventing motion of the seal ring within the groove. Preferably, the spring in a wave spring, wherein small changes in deflection of the wave spring produces small changes in the load generated by the spring on the seal ring. The seal ring has at least one radial spring ring mounted within the seal ring to create a radial force on the seal ring. The piston can also include a sleeve that mounts to the piston body, the sleeve forming a wall of the groove. The piston can be a displacer mounted within a cylinder of a refrigerator.