Abstract:
A gland packing provided in a fluid apparatus such as a pump and compressed in an axial direction so as to prevent penetration leakage of a fluid is provided.The gland packing has a packing base material 11 of a predetermined length including a band-like flat braid 12 braided by moving a plurality of yarns 13 along one track K. The band-like packing base material 11 is shaped into a ring by abutting longitudinal ends 12a and 12b of the packing base material 11 so that a width direction thereof is parallel with a packing axial direction, and is then compressed in the axial direction, whereby the packing base material 11 is overlappedly folded in a packing axial direction, with a longitudinal direction of the packing base material 11 as a direction of folding lines 14.
Abstract:
A gasket having a concentrically waved metal sheet, i.e., a core member, which has a PTFE sheet or an inorganic sheet of sealing-property layered and bonded on each of its opposite surfaces. The gasket makes it possible to ensure a stable sealing-property for a long period of time with a low to a high fastening-load applied. The metal sheet has valley portions, which were conventionally vacant gaps, and are filled with powdered sealing member to be embedded from the beginning. Therefore, the PTFE sheet or the inorganic sheet at the valley portions of the metal sheet that conventionally could not be compressed with a low fastening-load applied is compressed and even with the low fastening-load applied can secure a fastening surface-pressure over the entire surface. Further, since it is possible to suppress the deformation of the sheet in quantity, which was conventionally large, the PTFE sheet or the inorganic sheet each of low-fluidity are arranged so as not to be broken with a high fastening-load applied and the thinner PTFE sheet or the thinner inorganic sheet can be used.
Abstract:
The present invention relates to an annular sliding fluoroplastics member which is requested to have good mechanical properties, resistance to abrasion and wear, thermal conductivity, heat resistance, and the like, and also to a method of producing such an annular sliding fluoroplastics member. The annular sliding fluoroplastics member of the invention has a composite structure which mainly consists of fluorine plastics and short fibers, and 20 or more wt. % of short fibers by weight of a total amount of the short fibers are oriented in a direction along which a burden of a load is large. According to this configuration, the buckling resistance and the pressure resistance are enhanced. A member having a high buckling resistance can be used in a thrust slide bearing or a thrust washer in which a large press load is applied in the axial direction, and a member having a high pressure resistance can be used in a radial slide bearing in which a large press load is applied in a radial direction. In some cases, in the annular sliding fluoroplastics member of the invention, filaments consisting of long fibers may be stitched to the inner peripheral face or the like, the surface is covered with an expanded graphite sheet, or the member is impregnated with a lubricant. The member having such a structure is excellent in buckling resistance and pressure resistance in a radial direction, and also in resistance to abrasion and wear, thermal conductivity, etc. According to the production method of the invention, a cutting work step can be omitted, and therefore materials can be prevented from being wastefully used, and the production cost can be reduced.
Abstract:
A shaft seal apparatus that exhibits a good and reliable sealing performance, even when a rotating shaft undergoes axial vibration, eccentric revolution, or the like. This shaft seal apparatus has gland packings (2) stuffed in a sealed space (10) formed between a rotating shaft (9) and a stuffing box (1), with gland packings (2) pressed between a first packing gland (3) on a sealed liquid region side (7) and a second packing gland (4) on an atmospheric region side (8). The first packing gland (3) is fixed to a rotary equipment body (6) and the second packing gland (4) is to the stuffing box (1). A screw bolt (15) extending in the axial direction of the rotating shaft (9) is anchored to the first packing gland (3). The stuffing box (1) is provided with a through hole (16) larger than the screw bolt (15) in the flange (1a). The screw bolt (15) running through the through hole (16) has a tightening nut (17) thereon at a place which is out of and backward of the hole (16). A compression coil spring (18) is mounted on screw bolt (15) between flange (1a) and tightening nut (17).
Abstract:
The present invention relates to a metal-covered gasket in which a soft core member (2, 12, 22, 32, 42, 52) containing unexpanded or expanded vermiculite is covered with a metallic sheet (3, 13A, 13B, 23A, 23B, 33A, 33B, 43, 53A, 53B). There are provided good sealing properties by the soft core member mainly composed of inorganic fibers and treated unexpanded vermiculite the expansion amount and expansion force of which are increased due to ion exchange by treatment with chemicals, or by the soft core member solely made of expanded vermiculite. Reinforcing metallic sheets (44, 54) for restraining the vermiculite from transversely sliding and for further improving the entire shape retention may be embedded in the soft core member or laminated on the surface thereof.
Abstract:
The packing according to the present invention is composed of a string-like body formed of an elongated tape-like packing material having at least one layer is repeatedly folded in direction at a right angle to the longitudinal direction thereof in a zigzag manner with peak portions and valley portions alternately formed. According to the packing, the string-like body cut into a predetermined length according to the diameter of a shaft with which it is to be used may be wound on the outer peripheral surface of the shaft with the width or thickness direction of the string-like body directed in the radial direction of the shaft. Thus, the packing is versatile with respect to the shaft diameter. The packing itself produces no slip in the axial direction of a shaft. This prevents the packing from protruding, thus eliminating stress release due to a decrease in volume. The packing is used with the string-like body folded in the three-dimensional directions. Accordingly, the shaft-following properties of the packing at the time when the same is worn, are satisfactory and the decrease in sealing properties is restrained.
Abstract:
A gland packing having increased compressibility, increased allowable limit of twist, increased tensile strength, and excellent serviceability and versatility characteristics is disclosed which comprises a plurality of flexible graphite sheets cut to a width of less than 5 mm and laid in superposed relation to one another, the laid-up cut sheets being covered with a fiber material by knitting or braiding to form a knitting thread, the knitting thread being twisted. Also, a gland packing having a further increased tensile strength is disclosed wherein a plurality of strands of the knitting thread are gathered and twisted or braided. In addition, a gland packing having improved contacting and sealing properties is disclosed wherein the covering fiber material exposed on the surface of the packing is removed at least in part.
Abstract:
A packing is disclosed for hermetically sealing a member. The packing in accordance with the present invention comprises braiding yarns each of which includes a plurality of longitudinally arranged reinforcing fiber yarns and expanded graphite integrally bonded to at least one side of the reinforcing fiber yarns with adhesive, so that the braiding yarns are provided with excellent sealing properties and strong tensile strength and toughness. A plurality of such braiding yarns may be put together to form a core member. The core member may be covered, at the outer periphery thereof, with a braided body of the braiding yarns. A plurality of such braiding yarns as put together may be braided (square-knitted). Alternatively, a plurality of such braiding yarns as put together may be twisted. Thus, packing having a free length may be obtained. The packing thus obtained may be used as cut, at a site, to a predetermined length according to the size of the object member to be sealed. This eliminates production, based on estimations in advance, of a variety of annular packings according to the size of object members to be sealed, as done in molded packing.
Abstract:
The present invention provides a gland packing in which impairment of the sealing performance due to cracks that unwillingly occur in an end portion in the width direction of an expanded graphite tape of a braiding yarn in the gland packing can be suppressed. In gland packings 1, 2, braiding yarns include braiding yarns 10A in each of which an expanded graphite tape 30 is bent so as to contract in the width direction, and both end portions 31 in the width direction of the bent expanded graphite tape 30 are folded back, or braiding yarns 20A in each of which at least an outer end portion 31′ in the width direction of a twisted expanded graphite tape 30 is folded back.
Abstract:
In a braiding yarn made of expanded graphite 1, a reinforcing wire member 3 made of a stainless steel wire which is easily plastically deformed, and having a diameter of 0.05 to 0.2 mm is spirally wound around the outer periphery of a twisted expanded graphite base member 2 having a width of 3 mm and a thickness of 0.38 mm, at a narrow pitch P of 0.5 to 5 mm without slack. Alternatively, the reinforcing wire member is wound so as to be embedded in the inner side of and along an edge 4 of an expanded graphite tape which is spirally exposed from the outer surface of the expanded graphite base member 2.