Seal bearing assembly with annular cylinder of two outer cylindrical bearings and at least two braided packing members therebetween with all having equal inner and outer radii to fill the seal cavity of a mechanical device
A seal-bearing assembly to be inserted into the seal cavity of a mechanical device to provide a seal and a bearing surface to eliminate whip in a rotating, reciprocal, or rotating and reciprocal cylindrical member. The seal-bearing assembly is particularly well suited for use in a reciprocal pump or a piston-driven valve, or between the steam lance and fixed steam tube in a sootblower. The assembly includes at least a pair of outer substantially rigid cylindrical bearings having an inner bore to be positioned over the cylindrical member and at least one complimentary flexible textile packing ring substantially comprised of carbon disposed between the two outer bearing members. In assemblies including an additional bearing, the additional bearing is surrounded by at least one flexible packing on each side. The inner bore of the bearing members provides a bearing surface for eliminating whip of the moving elements in the device.
1. A seal-bearing assembly for a mechanical device having a shaft with reciprocating and/or rotational movement, comprising:
a first substantially rigid high performance polymeric cylindrical outer bearing;
a second substantially rigid high performance polymeric cylindrical outer bearing spaced apart from and axially aligned with the first outer bearing; and
at least two cylindrical textile packing members, each cylindrical textile packing member including carbon yarn and each being positioned adjacent to one of the first and second outer bearings,
wherein the first and second outer bearings are closely dimensioned to fit into the seal cavity of a device with an inner bore closely dimensioned to fit over the shaft and within the inner bore of the cavity of the device to provide a bearing surface for the shaft, and
wherein the cylindrical textile packing members each have an inner radius and an outer radius that are approximately equal to the inner and outer radii of the bearings to fill the seal cavity of a mechanical device.
2. The seal-bearing assembly of claim 1 , wherein at least one of the first and second outer bearings comprises high-temperature polymeric material or a formulation thereof.
3. The seal-bearing assembly of claim 2 , wherein the first and second outer bearings each comprise a high-temperature polymeric material selected from the group consisting of polyphenylene sulfide, polyimidazoles, fluoropolymers, polyamide-imides, polyimides, polyether ketone polymers, and formulations thereof.
4. The seal-bearing assembly of claim 3 , wherein the first and second outer bearings each comprise polytetrafluoroethylene or a perfluoroalkoxy polymer.
5. The seal-bearing assembly of claim 3 , wherein the first and second outer bearings each comprise polybenzimidazole or a formulation thereof.
6. The seal-bearing assembly of claim 1 , wherein at least one of the first and second outer bearings includes an external O-ring.
7. The seal-bearing assembly of claim 1 , wherein the cylindrical textile packing members are formed from at least 90 percent pure carbon fiber.
8. The seal-bearing assembly of claim 1 , wherein the cylindrical textile packing material including the carbon yarn also includes yarn selected from the group consisting of graphitized yarns, exfoliated graphite yarns, ceramic yarns, and glass yarns.
9. The seal-bearing assembly of claim 1 , wherein the cylindrical textile packing members include a lubricant material.
10. The seal-bearing assembly of claim 1 , wherein at least one packing member acts as a wiper to trap any mechanical displacement of carbon or other media particles.
11. The seal-bearing assembly of claim 1 , wherein each of the first and second outer bearings comprises polybenzimidazole, and a first carbon yarn flexible braided packing member is disposed adjacent to the first outer bearing for the plunger end of a pump, a flexible cylindrical textile packing member comprising helical braided Inconel wire overbraided with carbon inserted exfoliated graphite foil is disposed adjacent to the first carbon yarn flexible packing member, second and third carbon yarn flexible braided packing members are disposed adjacent to the helical braided Inconel wire packing member, and the second outer bearing is disposed adjacent to the second and third carbon yarn packing members at the spring end of the pump.
12. A seal-bearing assembly for a mechanical device having a shaft with reciprocating and/or rotational movement, comprising:
a first substantially rigid high performance polymeric cylindrical outer bearing;
a second substantially rigid high performance polymeric cylindrical outer bearing spaced apart from and axially aligned with the first outer bearing;
a third substantially rigid cylindrical bearing positioned between the first and second outer bearings; and
at least two cylindrical textile packing members, with each cylindrical textile packing member including carbon yarn and each being positioned adjacent to one of the first and second outer bearings,
wherein each of the cylindrical bearings is closely dimensioned to fit into the seal cavity of a device with an inner bore closely dimensioned to fit over the shaft and within the inner bore of the cavity of the device to provide a bearing surface for the shaft, and
wherein the cylindrical textile packing members each have an inner radius and an outer radius that is approximately equal to the inner and outer radii of the bearings to fill the seal cavity of a mechanical device.
13. The seal-bearing assembly of claim 12 , wherein the third cylindrical bearing comprises a lantern ring.