GB859525A - Fluid seal - Google Patents

Abstract

859,525. Stuffing-box substitutes; turbines; axial-flow and radial-flow compressors. ROSE, A. A. S. Sept. 29, 1959 [Oct. 9, 1958], No. 33047/59. Classes 110 (1), 110 (3) and 122 (5). A seal between a hollow member 42 and a rotary member 17 within the hollow member comprises an annular abutment 44 on the first member, a second abutment 45 on the second member, a plurality of plates 27 in contact with the second abutment and elastic means 37 mounting the plates on the second member such that in one position of the plates a gap is maintained between the outer peripheral edges 30 of the plates and the abutment 44 and in a second position determined by the speed of rotation of the second member, the edges are in sealing relation with the latter abutment. The rotary member 17 is shown as one of the discs of the rotor of the compressor of a gas turbine, and the member 42 is a sealing-ring on the engine spline 26. The plates 27, which may be of stainless steel, are arranged with a small gap between their ends so as to form a complete ring and are connected by the elastic means, in the form of leaf-springs 37, to a similar inner ring comprising plates 32, the leaf-springs being welded to both sets of plates. The plates 32 are clamped, as shown in Fig. 2, to the rotor 17 of the gas turbine compressor between an annular plate 41 and the rotor by bolts 40, the outer surface of the plate forming the second abutment surface 41 against which the plates 32 are urged by the gas pressure. On initial assembly of the seal to the rotor, a gap is provided between the edges 30 of the plates 27 and the abutment surface 44 but when the compressor is run up to maximum speed, the plates move outwardly under the action of centrifugal force into sealing contact with the surface 44. In order to overcome the effects of manufacturing tolerances, the springs 37 are of such strength that on the first run up to maximum speed of the compressor they allow the plates 27 to be forced outwardly so that the edges 30 wear away by the engagement thereof with the abutment 44 until a dimension is attained, such that on subsequent operations, the edges maintain the desired sealing contact; during this initial operation, the springs may be extended beyond their elastic limits. The end of the plates 27 may be arranged to overlap in order to seal the gap therebetween (Fig. 11, not shown) and, if desired, the ends may be tongued and grooved. The invention is applicable to turbines and radial flow compressors.