Seal assembly which is hydraulically actuated

Claim 1

A shaft seal, the shaft seal comprising a sleeve generally having rotational symmetry about an axis, the sleeve adapted to be affixed to a shaft, the sleeve having a generally radially extending flange portion and a bore; the radially extending flange having a first side and a second side, the first side being a generally annular planar first face, the second side having a similar or second face defining at least one generally back pumping generally spiral groove; a first clamping means for clamping said sleeve to a shaft disposed within the bore; a generally annular second clamping means disposed remote from the second side, the second clamping means defining a generally radially extending annular third face spaced from the first face of the annular flange, the third face being adjacent and spaced apart from the first face, the third face and sleeve defining an outwardly opening annular recess of generally elongate rectangular cross sectional configuration; a fixed housing adapted to receive a shaft passing through the sleeve, the fixed housing being disposed about at least a portion of the sleeve; the fixed housing defining a generally radially outwardly extending annular fourth face generally parallel to and spaced from the second face defining the spiral groove, the housing having supported thereon a generally annular sealing member, the annular sealing member having affixed thereto in liquid tight engagement at least one annular diaphragm, the annular diaphragm having at least one annular radially extending surface disposed adjacent the first face of the flange, the annular diaphragm being in communication with a first fluid supply passage; a second fluid supply passage communicating between space external of the means supporting the diaphragm and space adjacent the sleeve, first fluid discharge means located generally at a peripheral location communicating with a space between first and third faces and a second fluid discharge means at a generally peripheral location communicating with space between the second and fourth faces; where upon the application of fluid pressure to the first fluid supply passage, the diaphragm is displaced toward the third face.