Patent GB-827100-A (GB)
Title: Improvements in sealing devices between relatively rotatable coaxial parts
Inventor: WITCOMBE JOHN CHARLES
IPC: F16J15/36
Filed: 1957-06-05
Abstract: 827,100. Stuffing-box substitutes. MORGAN CRUCIBLE CO. Ltd. May 23, 1958 [June 5, 1957], No. 17951/57. Class 122 (5). In a sealing device for use between relatively rotatable parts and comprising a sealing ring, such as 16 (Fig. 2), adapted to be statically sealed to one of the parts, for example a rotatable shaft 14, by a resiliently deformable sealing element and to make facial rotary rubbing sealing contact with the other part, the sealing element has a double-tapered bore 1 (Fig. 1) formed by frusto-conical portions 2, 3 with their wider sections opposed and narrowing towards the ends of the bore whereby, when the element is mounted in its operative position, the wall 5 of the bore is deformed so that the element engages the shaft 14 or other part to which it is sealed with a greater pressure at or towards the ends of the bore than at its centre. The sealing element, which may be of rubber, is grooved at 6 to form lips 7 and 8 at each end of the wall 5 and an integral conical flange 9 joins the wall 5 between the grooves 6 and extends outwardly beyond one end of the wall, terminating in an enlarged peripheral portion 12. In the arrangement shown in Fig. 2, the flange 9 is pressed against the rear face 15 of the carbon sealing-ring 16, whose front face 17 is adapted to bear on a counter-face on the shaft housing (not shown), by a spring 18 interposed between a recess 13 in the flange and a collar 20 secured to the shaft. The seal is shown in the uncompressed condition; when compressed the ring 17 abuts the front end 23 of the wall 5. In the arrangement shown in Fig. 3, the sealing element is mounted in a casing 24 which may be of metal or plastic material and is press-fitted in a bore 25 in a pump housing and has a sleeve portion 26 surrounding the pump shaft 27 with clearance. The bore of the sealing element is in static sealing engagement with the sleeve 26 and the flange 9 is urged by a spring 31 against a carbon sealing ring 30 that is retained in the casing by inwardly turned tabs 35 on the casing and has projections 34 engaging recesses 33 in the casing to prevent relative rotation whilst permitting axial movement between the casing and the ring. The seal is shown in the upper and lower halves of Fig. 3 in the uncompressed and compressed conditions respectively. In a modification, Fig. 5 (not shown), a mechanical interlock is provided between the sealing element and the sealing ring and between the sealing element and the spring. In another modification, Fig. 6, the sealing element comprises a sleeve 46 having at one end a radial flange 53 and at the other end an inwardly-curved flange 47 terminating in an axial wall 48 having a doubletapered bore 49 in accordance with the invention and end lips 51, 52. The sleeve 46 and flange 53 are reinforced by a rigid L-shaped ring 54 and a spring 55 is interposed between the ring 54 and a carbon sealing ring 57 having an axial extension 58 in sealing contact with the bore 49, such contact allowing axial sliding movement between the ring 57 and the bore 49. The sleeve 46 is mounted in a bore 59 in a pump housing 60 and projections 64 on the ring 57 engage recesses 63 in the housing 60. The sealing device shown in Fig. 6 may be inserted in a rigid casing adapted to be press-fitted in a bore in the pump housing.