GB766717A - Improvements in or relating to sealing devices - Google Patents

Abstract

766,717. Stuffing-box substitutes. CRANE PACKING CO. Aug. 20, 1954, No. 24349/54. Class 122 (5). A sealing device for a rotary shaft, such as a pump shaft 14, extending through an opening 12 in a casing 10 comprises an annular sealing washer 28 surrounding and axially slidable with respect to the shaft, urged into end-face sealing contact with a radial surface 22 on the casing, and sealed to the shaft by at least one frustoconical sealing ring 66 of resilient deformable material pressed into a recess 56 in the washer so that it is in sealing engagement with the shaft, the bore 58 of the recess, and the outer portion of the bottom of the recess. The washer 28 is positively driven from the shaft by a retainer 30 having at its forward end ribs 46 engaging axial grooves 48 in the outer periphery of the washer and tongues 54 extending from its rear wall 38 and engaging in recesses 52 in the pump impeller 16 secured to the shaft. The rings 66, which may be of polytetrafluorethylene polymer sold under the Trade name " Teflon ", are pressed into the recess 56 and the washer 28 thereby urged into contact with the casing 10, by a spring 76 compressed between the rear wall 38 of the retainer 30 and a washer 72 having a rounded edge 74 contacting the rear washer 66 adjacent its inner periphery. The bottom 60 of the recess 56 is coned with an apex angle slightly greater than that of the rings 66 and acts as a support for the forward ring 66 when the latter is deformed. Axial movement of the sealing washer out of the retainer 30 is limited by lugs 44 on the front end of the retainer that engage the outer peripheral portion 50 of the washer. In a modification (Fig. 5) a seal 116 for a rotary shaft 104 comprises rotary and stationary sealing members 150 and 130 respectively, in mutual facial sealing contact, housed in a retainer secured to the shaft casing 100, and sealed to the shaft and retainer respectively by frusto-conical sealing rings 160, 142 of resilient deformable material axially urged into conical bottomed recesses 156, 134 in the members by a leaf spring 148 compressed between the rear wall 124 of the retainer and a washer 144 abutting ring 142; the sealing ring 160 being held at its outer periphery by a spacer ring 162 and abutting at its inner periphery a ball race 106 secured to the shaft. The retainer is formed by two telescoped shells 118, 120, the inner 120 having ribs 138 engaging axial grooves 140 in the member 130 and the retainer is held in a recess 112 in the casing by a spring ring 170 and sealed to the casing by a frusto-conical sealing gasket 174.