MXPA99007932A - Constant flow cascade lubrication system - Google Patents

Abstract

A system for lubricating bearings on a vertical rotatable shaft within a bearing housing, is comprised of an annular lower lubricant sump (40) at a lower portion of the bearing housing (11);an annular upper lubricant reservoir at an upper portion of the bearing housing;and a conduit providing fluid communication between the lower lubricant sump (12) and the upper lubricant reservoir (20). Provision is made for metering a flow of lubricant from the upper lubricant reservoir (20), into upper bearings (14). The lubricant is pumped from the lower lubricant sump (40), through the conduit (35),to the upper lubricant reservoir (20) at a rate exceeding the rate of metered flow into the upper bearings (14). A constant head of lubricant above the metering orifice is provided in the upper lubricant reservoir (20), as well as an outlet for shunting excess lubricant back to the lower lubricant sump.

Description

LUBRICATION SYSTEM IN CONSTANT FLOW WATERFALL FIELD OF THE INVENTION This invention relates, in general, to the lubrication of bearings in a rotating shaft and, in particular, to the supply of a lubricating fluid to the bearings, inside a vertical bearing housing with a wet manifold, at a constant flow rate that is independent of the speed of operation.

BACKGROUND OF THE INVENTION The present lubrication system of bearings for housings of vertical bearings with wet collector is normally designed to supply lubricant at a specific flow rate for a design operating speed. This system pumps lubricant from a manifold, in the lower part of the housing, to the bearings in the upper part of the housing. The lubricant flows down through the bearings and back into the manifold. The magnitude and flow rate of the lubricant supplied to the bearings are limited by the operating speed of the pump mechanism, the viscosity of the lubricant and the size of the passages through which the lubricant is pumped into the bearings. As long as these systems, which represent a 2221-16 / 8 constant viscosity, they perform adequately at design speed, they can become ineffective at low operating speeds or when they supply an excess of lubricant at a high operating speed, as would happen with a speed drive input. variable. In this way, at low speed the lubrication system may be inadequate, while at high speed the lubricant flow can cause overpressure leading to seal failure and lubricant leaks into the surroundings. In addition, lubricants are viscous liquids that are subject to changes in viscosity that are inversely related to temperature variations. In this way, increases in temperature cause reductions in viscosity and reductions in temperature cause increases in viscosity. Even when working at design speed, the lubricant can heat up due to the mechanical generation of heat and, therefore, loses viscosity. This causes a reduction in the pumping action and results in improper lubrication of the bearings. These limitations give rise to costly damage to equipment and the environment. The above illustrates the limitations that are known to exist in today's lubrication systems for vertical bearing housings with 2221-16 / 8 wet collector. It is clear that it would be advantageous to provide an improvement aimed at overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided which includes features that are set forth more fully below.

SUMMARY OF THE INVENTION In one aspect of the present invention, this is achieved by providing a system for lubricating bearings on a vertical rotating shaft within a bearing housing, which includes: a lower, annular lubricant manifold, disposed in the lower portion of the room; a lubricant tank, upper, annular, in an upper portion of the room; a conduit that provides fluid communication between the lower lubricant manifold and the upper lubricant reservoir; means for dosing the lubricant flow from the upper lubricant reservoir to the upper bearings; means for pumping lubricant from the lower lubricant manifold, through the conduit, to the upper lubricant reservoir, at a rate exceeding the flow rate metered to the upper bearings; and a medium in the upper lubricant reservoir to maintain a constant head of lubricant above the dosing medium and to 2221-16 / 8 divert excess lubricant and return it to the lower lubricant manifold.

BRIEF DESCRIPTION OF THE DRAWINGS The above aspects as well as other aspects will be apparent from the following detailed description of the invention when considered together with the accompanying drawings: Figure 1 is a vertical, schematic and partially sectioned view of a fitted pump with a vertical lubrication system with wet collector, in accordance with the invention; Figure 2 is a fragmentary bottom perspective view of the pumping device; and Figure 3 is a fragmentary view in elevation and in section of the dosing and lubricant deviation features of the upper lubricant reservoir.

DETAILED DESCRIPTION OF THE INVENTION All the main features of the invention can be seen with reference to Figure 1; however, it is also useful to refer to Figures 2 and 3, when appropriate, to appreciate other details of the pumping, dosing and deflection characteristics. In Figure 1, the invention is shown in the form in which it is applied to a vertical pump unit 60. A unit 50 of 2221-16 / 8 bearing housing has upper bearings 14 and lower bearings 18 that support a rotary shaft 5 that is mounted within the bearing housing 10. A lower annular lubricant manifold 40 in the cover 11 of the lower end of the housing 10 and an upper annular reservoir 20 of lubricant in the cover 12 of the upper end are connected by a conduit 35, which is preferably drilled in the wall of the housing 10. A cup-like lifting or pumping device 30, which is fixed to the rotating shaft 5, pumps the lubricant by means of at least one helical groove 33 on the outer surface thereof, this groove cooperates with the inner wall 31 of a borehole through which the cup-type pumping device 30 extends downwardly towards the lower lubricant manifold 40. Note that there is no contact between the cup-type pumping device 30 and the inner wall 31 of the borehole. The groove 33 is dimensioned in such a way that it pumps an excess amount of lubricant to the upper bearings 14, at all operating speeds. These features are seen in Figures 1 and 2. The upper lubricant reservoir 20, seen in Figures 1 and 3, has an overflow barrier or weir 26 that keeps a head 2221-16 / 8 of constant pressure on the dosing orifice 25. The dosing orifice 25 is dimensioned to provide full lubrication, as required by the upper bearings 14, at all operating speeds and viscosity ranges. The dosing orifice 25 has its mouth located slightly above the bottom of the upper tank 20 so that, during shutdown, a small amount of lubricant is retained in the tank 20. This ensures a minimum response time to supply lubricant to the upper bearings 14 when the unit is restarted after it has been turned off. Any excess lubricant that reaches the upper reservoir 20 passes over the overflow barrier 26 and is diverted and returned to the lower manifold 40, through the deflection passage 19. This particularity of overflow and deviation allows the pumping device operate without chokes or any other restriction, regardless of the speed of operation, because all the lubricant requirements are always satisfied since any excess lubricant is simply returned to the lower manifold 40. A part of the excess lubricant is directed, for the lower bowl-shaped surface of the housing 10, through the lower bearings 18 before being drained to the lower manifold 40. 2221-16 / 8 The lubricant passing through the upper bearings 14 falls on the deflector ring 45 connected to the arrow 5 below the bearings 14. The deflector ring 45 throws the lubricant against the wall of the housing 10, where the lubricant yields the heat collected when making contact with several parts of the bearings and * of the arrow 5. By design, the lubricant that is not actually lubricating the bearings, is exposed as far as possible to more cold inside the housing 10 of bearings. This helps dissipate the heat and maintain a steady state operating temperature. The cup type pumping device 30 also acts as a heat sink to extract heat from the arrow 5 adjacent to the lower bearing 18. Mixing by intimate contact between the lubricant and the pumping device 30 ensures maximum heat transfer to the lubricant, which then serves to transport the heat towards the walls 10, 11 and 12 of the housing and thus dissipate it towards the surroundings of the housing unit 50. This feature is especially important if the arrow 5 is exposed to an external heat source, such as a hot pumping liquid or hot air. In this way, in any operating condition, the bearing housing unit 50 quickly reaches a 2221-16 / 8 operating temperature in steady state. A seal is provided to prevent leakage of the lubricant from the lower manifold 40. This is achieved without contact between the stationary and rotating parts. The lower manifold 40 has an inner wall 39 which extends above the top of the stationary lubricant level and, without making contact with it, surrounds the arrow 5 and effectively provides a static seal. No additional sealing would be required, with the exception of the turbulence induced in the lubricant within the lower manifold 40. To counteract the turbulence-induced loss of lubricant, a non-contact, axial, dynamic, counterflow back-sealing device is provided using the pumping device 30 of the cup type. A helical groove 36 on the inner surface of the pumping device 30, which has a threading opposite that of the pump groove 33, pumps the lubricant downwards during the operation. The groove 36 cooperates without contact with the outer surface of the inner wall 39, in the same way that the groove 33 cooperates without contact with the wall 31 of the borehole. The bearing lubrication system has been shown in Figure 1 applied to a pump. It is very evident that any housing of vertical bearings that is lubricated by a system of 2221-16 / 8 humid collector lubrication can benefit from the features disclosed here. 2221-16 / 8

Claims (18)

1. CLAIMS 1. A system for lubricating bearings in a vertical rotary shaft within a bearing housing, comprising: a lubricant manifold, lower, annular, in the lower portion of the bearing housing; a lubricant reservoir, upper, annular, in the upper portion of the bearing housing; a conduit that provides fluid communication between the lower lubricant manifold and the upper lubricant reservoir; means for dosing a lubricant flow from the upper lubricant reservoir to the upper bearings; means for pumping lubricant from the lower lubricant manifold, through the conduit, to the upper lubricant reservoir, at a rate exceeding the flow rate metered to the upper bearings; and a means in the upper lubricant reservoir to maintain a constant head of lubricant above the metering medium and to divert excess lubricant back into the lower lubricant manifold.
2. 2 . The system according to claim 1, in 2221-16 / 8 where the means for pumping lubricant from the lower lubricant manifold, through the conduit and into the upper lubricant reservoir also serves as a heat dissipating means for extracting heat from the lower bearings and for transferring the heat towards the lubricant for its dissipation towards the surroundings of the housing.
3. The system according to claim 1, further comprising: a means in the lower lubricant manifold to provide a non-contact seal, in order to retain lubricant within the bearing housing.
4. The system according to claim 1, wherein the means for dosing the lubricant flow from the upper lubricant reservoir to the upper bearings comprises at least one passage through the lower wall of the upper lubricant reservoir up to the upper bearings, this at least one passage is dimensioned to provide a full flow of lubricant to the bearings, regardless of the speed of operation.
5. The system according to claim 4, wherein the means in the upper lubricant reservoir for maintaining a constant head of lubricant and for deriving the excess lubricant, comprises an external wall of the upper lubricant reservoir that 2221-16 / 8 has an overflow to a bypass passage that drains the excess lubricant through the bearing housing and back into the lower lubricant manifold.
6. The system according to claim 1, wherein the means for pumping lubricant from the lower lubricant manifold, through the conduit, to the upper lubricant reservoir, comprises a collar practically cylindrical and fixed to the rotating shaft, below the lower bearing, and having a cup-like portion extending down through a bore in the lower wall of the bearing housing towards the lower lubricant manifold, the cup-like portion is forcedly fitted into the bore and has a helical groove on its external cylindrical surface that elevates the lubricating fluid through the conduit to the upper lubricant reservoir.
7. The system according to claim 6, further comprising: a means on an internal cylindrical surface of the cup-like portion to provide a non-contact seal, in order to retain the lubricant within the bearing housing.
8. The system according to claim 7, wherein the means for providing a non-contact seal comprises a helical groove that 2221-16 / 8 has a threading opposite that of the groove on the outer cylindrical surface and which is in close proximity to an annular wall, the annular wall surrounds the rotating shaft and extends upwards from the lower wall of the lubricant manifold lower to a point slightly below the point of attachment of the collar practically circular with the rotating arrow, the helical groove acts to produce backflow of fluid towards the annular wall, in order to dynamically oppose the lubricant leak from the bearing housing.
9. The system according to claim 1, further comprising: means for dissipating excess heat from the lubricant to the surroundings of the bearing housing.
10. The system according to claim 9, wherein the means for dissipating excess heat from the lubricant comprises a deflector means fixed to the rotary shaft, below the upper bearings, to divert the lubricant coming from the bearings towards the walls side of the housing and direct the entire flow of the lubricant that is not passing the bearings towards the walls of the housing in order to relatively cool them.
11. 11. The system according to claim 3, in 2221-16 / 8 where the means, in the lower lubricant collector, to provide lubricant retention without contact, comprises an annular wall surrounding the rotary shaft and extending upwardly from the lower wall of the lower lubricant manifold , up to a point above the level of stationary lubricant in the manifold, the annular wall is stationary and does not contact the rotating shaft or any moving part.
12. 12. A pumping device comprising: a cup-type rotating member having, on its inner and outer surfaces, longitudinally directed helical grooves and opposite threads; a smooth-walled bore in a stationary member that closely surrounds the outer surface of the rotating cup-type member without contacting it; a stationary cylindrical member with a smooth wall tightly surrounded by the internal surface of the cup-like member, but without contacting it; and a manifold containing fluid at a level sufficient to cover the lower portion of the rotating cup-type member, the smooth-wall bore and the smooth-walled cylindrical member, such that rotation of the cup-like member causes the fluid to be pumped up on a surface 2221-16 / 8 and down on the other surface of the cup-like member.
13. The pumping device according to claim 12, wherein the fluid is pumped upwardly on the outer surface of the cup-like member and downwardly on the inner surface thereof.
14. 14. A system for lubricating bearings in a rotating vertical shaft within a bearing housing, comprising: a lower lubricant manifold in a lower portion of the bearing housing; a top lubricant reservoir in an upper portion of the bearing housing; a conduit that provides fluid communication between the lower and upper lubricant collectors; means for dosing a lubricant flow, induced by gravity, from the upper lubricant reservoir to the upper bearings; means for pumping lubricant from the lower lubricant manifold, through the conduit and to the upper lubricant reservoir, at a velocity exceeding the gravity-induced flow velocity towards the upper bearings; a medium, in the lubricant reservoir 2221-16 / 8 upper, to keep a constant head of lubricant above the metering medium and to divert excess lubricant and return it to the lower lubricant manifold; and a means for feeding a portion of the excess lubricant to the lower bearings before the excess lubricant is returned to the lower lubricant manifold.
15. The system according to claim 14, further comprising: a means, in the lower lubricant manifold, for providing a non-contact seal for retaining the lubricant within the bearing housing.
16. The system according to claim 14, wherein the means for dosing a lubricant flow, induced by gravity, from the upper lubricant reservoir to the upper bearings, comprises at least passage from the upper lubricant reservoir to the upper bearings , this at least passage is dimensi to provide all the lubricant flow required towards the bearings at all operating speeds.
17. 17. A system for lubricating bearings in a rotating vertical shaft within a bearing housing, comprising: a lower lubricant manifold in a 2221-16 / 8 lower portion of the bearing housing; a top lubricant reservoir in an upper portion of the bearing housing; a conduit that provides fluid communication between the lower lubricant manifold and the upper lubricant reservoir; means for metering a lubricant flow from the upper lubricant reservoir to the upper bearings; means for pumping lubricant from the lower lubricant manifold, through the conduit, to the upper lubricant reservoir at a velocity exceeding the flow rate metered to the upper bearings; a means, in the upper lubricant reservoir, for maintaining a constant head of lubricant above the metering means and for diverting the excess lubricant and returning it to the lower lubricant manifold; and a means for feeding a portion of the excess lubricant to the lower bearings before the excess lubricant is returned to the lower lubricant manifold. The system according to claim 16, wherein the means for pumping lubricant from the lower lubricant manifold, through the conduit, to the upper lubricant reservoir, also acts as a heat dissipating means for 2221-16 / 8 extract heat from the rotating shaft adjacent to the lower bearings and to transfer heat to the lubricant for dissipation into the surroundings. 2221-16 / 8