Seal

A seal for use between a pair of elements which are capable of relative movement with respect to each other where one element has a substantially circular cross section, said seal comprising a bush configured to be received in close abutting relationship with the one element and being associated at one end with a sealing element of corresponding cross-section, the radially outer circumferential face of said bush being formed with an annular ridge having a sloping face, said sealing element having a helical configuration, opposed axial faces of the helix are of complementary configuration and are in close abutting relationship, the opposed axial faces of the helix and said bush are of a complementary configuration and are in close abutting relationship, said bush and sealing element being integral and being formed of a resilient wear resistant material having a low coefficient of sliding friction and a high modulus of rigidity, a further bush is located at the other end of the sealing element and is integral with the other end of the sealing element, the radially outer circumferential face of said further bush being formed with an annular ridge having a sloping face, said seal further comprising an elastomeric sleeve extending over the radially outer circumferential face of the sealing element, over the annular ridges and beyond both ends of the sealing element, said sleeve applying a radial force to the seal in the direction of the one element and said sleeve being stretched axially and mechanically engaged with said sloping faces to supply an axially compressive force on the seal by elastomeric axial contraction of the sleeve, the bush being adapted to be supported by the other element.