Means providing coolant between elements of radial face seals

Claim 2

A positive clearance radial face seal comprising two sealing members mounted respectively on relatively rotatable shaft and housing members and each having opposed portions defining annular sealing faces having a radial clearance therebetween forming a communicating path between regions of higher and lower pressures, wherein at least one of the sealing members has a cavity behind its sealing face and defined, at least in part, by the portion of the material of the sealing member behind said sealing face, a porous thermally-conductive mass having interconnecting pores located in said cavity and in intimate thermal contact with the material of said portion, and said cavity having inlet means and outlet means for flowing a cooling fluid through the interconnecting pores of the porous mass in the cavity.

Claim 3

A seal according to claim 1, wherein said at least one sealing member comprises a collar comprising two ring members of different diameters, the smaller diameter ring member having a radially outward annular flange at one end constituting a first wall portion defining the sealing face and the larger diameter ring member having a radially inward annular flange constituting a second wall portion which, when the rings are assembled to form the collar, is spaced from the rear face of said first wall portion to form said cavity behind said first wall portion and is also spaced at its inner periphery from the smaller diameter ring member to provide said inlet means communicating with a space in the collar behind the second wall portion, and, wherein the porous mass in the cavity comprises sintered material, and means are provided for admitting cooling fluid to the space in the collar behind the second wall portion to flow through the inlet means and radially outward through the porous mass to the outlet means comprising the outer peripheral gap between the first and second wall portions.

Claim 4

A seal according to claim 2, wherein said outlet means includes circumferentially spaced holes in a ring overlying said peripheral gap, and means for closing selected ones of said holes.

Claim 5

A seal according to claim 2, wherein said at least one sealing member is the rotatable sealing member of the seal, and cooling fluid is admitted to said space in the collar behind the second wall portion by way of holes extending from the sealing face of the first wall portion through said first wall portion, the porous mass and the second wall portion, the ends of the holes in said sealing face rotating opposite a recess in the sealing face of the stationary sealing member to which the cooling fluid is fed through the stationary sealing member.

Claim 6

A seal according to claim 2, wherein the sealing face of the other sealing member comprises a pressure-deflectable elastic or elastically-loaded element which initially provides a substantially planar sealing face in the radial direction and which deflects, in the steady state operating condition, to provide a clearance between the sealing faces which converges in the radial direction to a minimum clearance at the downstream zone of the seal, the deflection changing with variations in the operating conditions in a manner to increase the convergence in the radial direction towards said downstream zone of the seal under the action of increased load on the seal tending to restore said steady state minimum clearance.

Claim 7

A seal according to claim 5, wherein the deflectable element comprises an annular flexible element having reinforcing rigid annular portions extending around its internal and external peripheries respectively, one of said rigid annular portions being secured adjacent one periphery of the end face of a mounting member of said other sealing member and the other said rigid annular portion is slidable relative to and sealed against the said mounting member, the space between the intermediate flexible annulus of the deflectable element and the end face of the mounting member being vented to the low pressure region of the seal.

Claim 8

A seal according to claim 4, wherein the cooling fluid is admitted at a pressure greater than that of the fluid in the high pressure region of the seal and also acts as a buffer fluid.