| abstract |
A seal assembly 10 for cooperating with a shaft 14, has a seal ring 16, which may be segmented, biassed radially inwards against the shaft and means are provided for applying a radially outward force to the seal member, to enable the seal assembly to be fitted to and disassembled from the shaft. The seal ring 16 or a garter spring 24, attached to the seal ring, may have magnetic properties and a collar 30 with magnetic coils used to provide the radially outward force. In an alternative construction the garter spring 24 is attached to the seal ring 16 and has an inflatable tube within it the expand the garter spring (Fig. 2). In another construction the garter spring is formed of electrostrictive material and supplied with current. |