Low profile overhead bearing assembly for pump bearing assembly

An improved pump and sealing assembly having particular utility to vertically extending pumps/pump shafts provides an arrangement that enables field repair as opposed to requiring travel of the host vessel to a shipyard. The apparatus includes an adapter housing that is configured to provide easy access to set screws that enable field disassembly. This adapter housing carries a sleeve and a bearing. The adapter housing can be fitted to a pump seal assembly that can include a mechanical seal and under bearing assembly.

Not applicable

REFERENCE TO A “MICROFICHE APPENDIX”

Not applicable

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to bearings and seals for vertical shaft style pumps having an overhead bearing assembly (OBA) and an underseal bearing assembly (UBA) wherein an improved, low profile OBA which stabilizes the pump shaft to minimize shaft wobble, thus prolonging seal life, can be installed in the field.

2. General Background of the Invention

Vertical shaft pumps are commercially available pumps (e.g., www.ruitepump.com) that can employ an overhead bearing assembly or OBA and an underseal bearing assembly or UBA.

Vertical shaft pumps that use both an overhead bearing assembly and an underseal bearing assembly are often used in the marine industry such as on barges. In order to remove the underseal bearing assembly or “UBA”, the barge or other vessel must typically be taken to a shipyard. This presents extra expense and loss of time to the operator of the vessel.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a method and apparatus for installing an overhead bearing assembly which can be field installed with little or no modifications to the pump itself. The present invention is a low profile apparatus preferably utilizing a straight outer diameter (OD) ball bearing and a piloted register to force the shaft of the pump to center. While straight outer diameter ball bearings are preferred, one could use a spherical OD bearing. Also, one could use a non-piloted version of the bearing (though a piloted register is preferred).

The present invention increases bearing life and allows the overall assembly to be shortened. The shorter assembly allows installation of an overhead bearing assembly and an under seal bearing assembly. The method and apparatus of the present invention enables one unit to cover multiple different configurations. That is, the present invention can be utilized with different kinds of pumps that employ OBAs. Another benefit of the present invention is that it provides a stabilizer arrangement that prevents pump shaft wobble, thus increasing the life of the mechanical seal.

An overhead bearing assembly of the present invention has a lower profile than prior art overhead bearing assemblies. This lower profile is useful due primarily to the existence of an under-seal bearing assembly (UBA) already installed on the pump. Prior art overhead bearing assemblies will not fit on a pump equipped with a UBA and would require removal of the UBA to install. To remove the UBA and install a prior art overhead bearing assembly would require a trip to a shipyard and lift equipment (a crane). The present invention makes it possible to install an OBA in the field. The low profile of the OBA of the present invention is preferably achieved by replacing the spherical OD bearing with a thinner, straight OD bearing. The straight OD bearing is preferred, as it increases the rigidity of the assembly therefore attenuating more run-out and shaft vibration.

Also, the housing containing the OD bearing is preferably also made thinner.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1-12show a preferred embodiment of the apparatus of the present invention designated generally by the numeral10. Pump and pump bearing apparatus10can be a new pump or can be a retrofit to a commercially available pump11of the type having pump shaft12which is generally vertically positioned (e.g., seeFIGS. 1 and 3). In general, such pumps are commonly used in the marine industry (e.g., on barges). Examples of such pumps include Ruhrpumpen, Byron Jackson, Flowserve, Goulds, ERL and other similarly configured vertical turbine pumps. A mounting plate13can be provided such as at a ship or barge deck. As seen inFIG. 3, the lower end of the shaft12drives an impeller14that can be surrounded with strainer15. The impeller14is contained within a casing or impeller housing16that is connected to a discharge pipe17. A mechanical seal23is provided (seeFIGS. 2, 5, 10, 11, and 12). The maximum thickness of mechanical seal23can be between about 1.264 and 1.4 inches. Pump effluent discharges at outlet50below seal23(seeFIG. 1). Openings51,52provide access to seal23. There can be an under bearing assembly or UBA at22(seeFIGS. 5, 10-12). Such mechanical seal23and under bearing assembly22can be seen for example in U.S. Pat. No. 7,699,579 which is hereby incorporated herein by reference.

A column or housing18surrounds shaft12(seeFIG. 3). Housing18extends between mounting plate13and casing or impeller housing16. At the upper end portion19of pump11there is provided bearing housing20(seeFIG. 4). Bearing housing20contains overhead bearing assembly21and underseal bearing assembly22(seeFIG. 5). Openings51-52can be in bearing housing20.

Overhead bearing assembly can be made of stainless steel, steel or brass, for example. When made of stainless steel, one could use 303 Stainless Steel (or 304, or 316, or 17-4 Stainless Steel), for example.

The apparatus10of the present invention features an adapter housing25which carries ball bearing26, sleeve27and retaining ring28(seeFIGS. 6-9). Adapter housing25can be made of stainless steel, steel or brass, for example. When made of stainless steel, one could use 303 Stainless Steel (or 304, or 316, or 17-4 Stainless Steel). Ball bearing26can be a high capacity ball bearing, for example. Sleeve27has sleeve central opening41that is occupied by pump shaft12. Sleeve27is held in position on shaft12with multiple set screws29. Sleeve27has annular groove30that is receptive of retaining ring28. Sleeve27also has annular shoulder44. Bearing26(e.g., ball bearing) is secured between annular shoulder44and retaining ring28. Side portions33,34each can provide one or more pairs of openings36,53. The openings can be different to facilitate use on multiple pumps. For example, one set of openings,36, could be a ⅝″ bolt hole pattern 6.5″ bolt circle for use with Ruhrpumpen, Byron Jackson, and ERL design pumps. Another set of openings,53, could be a ½″ bolt hole pattern 6.5″ bolt circle for use with Goulds pumps. Although the figures present different embodiments showing either both openings36,53or only openings36, the present invention can include embodiments of either or both type of openings. Arc shaped recesses31,32allow easier access to the set screws (seal driver set screws)29. Recesses31,32can be other shapes instead of arc shaped, but the arc-shaped recesses are less expensive to install and provide greater strength of the overall unit. Laterally extending space or recess35also allows easier access to the seal driver set screws29. Openings36are bolt hole openings that enable a bolted connection (e.g., bolts24,FIG. 5) of adapter housing25to mechanical seal23.

Adaptor housing25has upper surface37and lower surfaces38,39. Lower surfaces38,39are lower than surface40as seen inFIG. 6. The surface40extends laterally from one arcuate recess31to the other arcuate recess32as seen inFIGS. 6-9. Surface40includes curved sections at42,47. A cylindrically shaped socket43is provided in adapter housing25. Cylindrically shaped socket43is receptive of bearing26and sleeve27upon assembly. The assembled position of socket43, bearing26and sleeve27is seen inFIGS. 6-12. Lower bearing seal22includes bushing46which fits around shaft12and housing45which fits bushing46. Bushing46is thus an interface between shaft12and housing45. Bushing46can be a cylindrical sleeve of stainless steel material. Bushing46could also be made of steel or brass, for example.

The low profile OBA of the present invention can be configured to fit the common pump shaft sizes of 1 7/16″, 1½″, and 1 15/16″. One can also, by producing a custom center sleeve, fit any shaft size 2″ or smaller, for example. Larger sizes could also be made, though it is unlikely that a shaft would be larger than 3″.

When used with most pumps, the adapter housing of the overhead bearing assembly of the present invention preferably has a thickness of less than 3″, and more preferably less than 2.75″. The adapter housing of the overhead bearing assembly can have a thickness of between about 2.25″ and 2.5″, for example. Thickness refers to the height of the housing when the OBA is properly installed in a pump with a vertical shaft.

Bolts and screws can be made of, for example, stainless steel, or steel but stainless is preferred. When made of stainless steel, one could use 303 Stainless Steel (or 304, or 316, or 17-4 Stainless Steel), for example.

PARTS LIST

Part Number Description

10pump bearing assembly/apparatus11pump12pump shaft13mounting plate14impeller15strainer16casing/impeller housing17discharge pipe18column/housing19upper end portion20bearing housing21overhead bearing assembly (preferably less than 5″ high, more preferably less than 4″ high, and even more preferably less than 3″ high—for example, it can be 2.561″ high)22under bearing assembly/lower bearing seal23mechanical seal24bolt25adapter housing (preferably 2-10″ in diameter, more preferably 3-9″ in diameter, and most preferably 4-9″ in diameter (typically about 8″ in diameter); preferably less than 4″ high, more preferably less than 3″ high, and even more preferably less than 2.5″ high—for example, it can be 2.047″ high)26bearing/ball bearing27sleeve (preferably less than 3″ high, more preferably less than 2″ high, and even more preferably less than 1″ high—for example. 0.514″ high)28retaining ring29set screw/seal set screw/seal driver set screw30annular groove31arcuate recess32arcuate recess33side portion34side portion35laterally extending space (preferably at least 0.25″ high, more preferably at least 0.5″ high, and most preferably at least 0.8″ high—for example, it can be 0.85″ high)36opening37upper surface38surface39surface40surface41sleeve central opening (preferably the same diameter as the shaft for which it will be used)42curved portion43cylindrically shaped socket44annular shoulder45UBA housing46UBA bushing47curved portion50discharge outlet51access opening52access opening53opening
The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.