Patent ID: 8602419

Claim:
A dynamic shaft seal assembly for sealing a rotating or reciprocating shaft, the seal assembly comprising: an elastic seal member having at least a portion thereof in sealing communication with the rotating or reciprocating shaft; and a shape memory alloy element in contact with the elastic seal member, wherein the shape memory alloy element comprises a plurality of wires circumferentially disposed about the portion of the elastic seal member, each of the plurality of wires having a different transformation temperature configured to increase a stiffness of the elastic seal member in steps as temperature is increased, and is configured to i) directly apply a compressive force in a radial direction on the seal member against the rotating or reciprocating shaft, and ii) maintain the compressive force on the seal member as a function of temperature; wherein the seal assembly is adapted to seal at a temperature range from about −55° C. to about 250° C.