Method and apparatus for improving the delivery of oil of a wick lubricating system for a locomotive traction motor support bearing

An improved wick-holder for mounting a felt lubricating wick is provided with a passive inertia-activated pump mounted for submersion in the axle-cap lubricant-reservoir at a level that ensures that for all levels of the reservoir, the pump inlet is submerged in the lubricant of the reservoir. In a first embodiment, the passive inertia-activated pump takes the form of a piston-type pump, while in a second embodiment, the passive inertia-activated pump takes the form of a diaphragm pump. In either embodiment, the inlet of the passive inertia-activated pump is submersed in the lubricant-reservoir, and the output of the passive inertia-activated pump is directed to the surface-interface between the felt wick and the axle journal surface-area to increase the lubrication thereof over and above that which normally ensues owing to the conventional capillary action of the felt wick. In a modification of the first embodiment, the piston pump is mounted to a splash sleeve forming part of the wick-holder and which is telescopingly received over the free end of the felt wick, with the output of the passive inertia-activated pump delivering the lubricant to the surface-interface between the felt wick and the axle journal surface-area via the hollow interior-volume of the splash sleeve and wick holder proper. The slosh pump of the invention may replace the wick assembly entirely, whereby the lubrication is achieved solely by the slosh pump of the invention.

CROSS REFERENCE TO RELATED APPLICATION

Reference is had to co-pending application Ser. No. 11/284,635, filed on Nov. 21, 2005, which application is incorporated by reference herein.

BACKGROUND OF THE INVENTION

The present invention is directed to a method and apparatus for improving the oil delivery of a lubricating system for lubricating the axle-journal surface mounted in a support bearing of a locomotive traction motor. The oil-wick delivery system for lubricating the axle-journal surface mounted in a support bearing of a locomotive traction motor includes a wick holder that supports and mounts a central lubricating wick having a lower end portion or section received in an oil reservoir, which oil, via capillary action, is delivered by the wick to the axle-journal surface by means of a window formed in the shell of the traction motor support bearing. The other, upper wick-face section of the wick is received in the window for contact against the axle-journal surface, to thereby provide the proper lubrication.

Examples of this lubricating system are disclosed in the U.S. Pat. Nos. 2,980,472; 3,827,769; 3,905,659; 4,229,056; and 5,082,089. One such prior-art system is also shown inFIG. 1, and is indicated generally by reference numeral10, and includes an oil reservoir12for storing lubricant, and a carrier assembly14connected to the axle cap16of a friction support bearing18used for mounting a locomotive traction motor to the wheel axle assembly. The carrier assembly14has a spring22, such as a coil or torsion spring, that biases a wick-holder unit34toward a wick window, or lubricating opening,26formed in the shell of the friction support bearing18, through which window oil is delivered to the axle-journal surface37mounted in the friction support bearing. The wick-holder unit consists of a slide bracket element or member32which is mounted for sliding movement in the carrier assembly14, a wick holder member34of arcuate shape that is connected to the slide bracket element32, and a felt wick36having an upper section of similar arcuate shape mounted in the wick holder34. The wick defines a wick-face36′ that contacts the axle-journal surface37.

In Applicants' above-mentioned co-pending application Ser. No. 11/284,635, there are disclosed various embodiments for increasing oil-wick lubrication for a friction support bearing of a locomotive traction motor by means of providing louver-reservoirs or reservoir-pockets that are formed either as part of the wick-holder or as part of a separate splash sleeve that is mounted over, and connected to, the lower end portion of the felt wick. These reservoir-pockets receive and store oil that has been splashed and sloshed in the main oil-wick reservoir during normal locomotive operation, to thereby temporarily store and delivery this captured oil to upper portions of the felt wick for enhanced lubrication by the felt wick. This enhanced lubrication by the felt wick has special relevance and advantage when the level of the oil of the main oil reservoir for the wick has been reduced to a minimum level.

In the non-pressure lubrication system of which the present invention is used, it would be highly beneficial to ensure that the proper rate of lubricant is delivered to the axle-journal surface mounted in the support bearing of the locomotive traction motor, so that a concomitant decrease of wear and tear and lengthening of the service life of the axle-journal surface-area occurs. The present invention is directed to providing such an optimal flow rate of lubricant to the axle-journal surface-area via face of the wick lubricator, independent of the oil level present in the reservoir between maximum and minimum service levels.

SUMMARY OF THE INVENTION

It is, therefore, the primary objective of the present invention to provide a supplemental lubricant-delivery system for enhancing the lubrication of the axle-journal surface-area by optimizing the amount of oil delivered to the face of the wick lubricator and, therefore, to the axle journal surface-area, which optimized oil-delivery is independent of the oil level present in the reservoir between maximum and minimum service levels.

It is, also, the primary objective of the present invention to provide such a supplemental lubricant-delivery system which incorporates a passive inertia-activated slosh pump located internally to the main axle-cap oil-reservoir.

It is another primary objective of the present invention to provide such a supplemental lubricant-delivery system which incorporates a passive inertia-activated pump located internally to the main axle-cap oil-reservoir, which pump is driven by the inertial resistance to the vertical and lateral accelerations imposed upon the traction motor by rail irregularities encountered during normal operation.

It is yet another primary objective of the present invention to provide such a supplemental lubricant-delivery system which incorporates a passive inertia-activated pump located internally to the main axle-cap oil-reservoir, which passive inertia-activated pump delivers the oil from the axle-cap oil-reservoir to a location close to the contact-face of the felt wick with the axle-journal.

In accordance with the present invention, an improved lubricating system for use with a wick-holder mounting a felt lubricating wick is provided with a passive inertia-activated pump mounted for at least partial submersion in the axle-cap lubricant-reservoir whereby at least the pump inlet is submerged in the lubricant of the reservoir. In a first embodiment, the passive inertia-activated pump takes the form of a piston-type pump, while in a second embodiment, the passive inertia-activated pump takes the form of a diaphragm pump. In either embodiment, the inlet of the passive inertia-activated pump is submersed in the lubricant-reservoir, and the output of the passive inertia-activated pump is directed to the surface-interface between the felt wick and the axle journal surface-area to increase the lubrication thereof over and above that which normally ensues from that owing to the conventional capillary action of the felt wick. In a modification of the first embodiment, the passive inertia-activated piston pump is mounted to a splash sleeve forming part of the wick-holder which is telescopingly received over the free end of the felt wick, with the output of the pump delivering the lubricant to the surface-interface between the felt wick and the axle journal surface-area interiorly via the hollow interior-volume of the splash sleeve and wick holder proper.

In another embodiment, the passive inertia-activated pump of the invention entirely replaces the prior-art wick-lubricating system, to be the only delivery source of lubricant to the surface-interface between the support bearing and axe journal.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings in greater detail, and in particular toFIGS. 2-7, there is shown a first embodiment of the improved wick-lubricant delivery system for enhancing and optimizing lubricant flow to the face of the wick used to lubricate an axle-journal surface supported in a locomotive traction-motor friction support bearing. In accordance with this first embodiment, a passive inertia-activated slosh pump in the form of a piston-type pump assembly40is provided, and is vertically mounted to, and below, the wick carrier-assembly14via mounting bracket40′. Mounting bracket40′ positions the pump assembly below the spring22. The pump assembly42has a pump inlet valve42′ and a pump outlet valve42″. Projecting vertically downwardly from the inlet valve42′ is an inlet tube44having a lower inlet-opening44′ deeply submerged in the oil-reservoir12, so that droplets of oil may be taken in through the inlet-opening44′ and delivered to the pump inlet valve42′ via the inlet tube44. Projecting at a upward slope from the pump outlet valve42″ is an outlet-tube46having an upper outlet-opening46′. The outlet-tube46is located exteriorly of the wick-holder, with the outlet-opening46′ thereof terminating at the wick-face36′ of the felt wick36, so that droplets of oil taken up through the inlet-opening valve44′ and delivered to the pump inlet valve42′ via the inlet tube44are delivered to the wick face36′ during normal operation, as described hereinbelow, in order to supplement normal wick oil-delivery.

The passive inertia-activated slosh pump assembly40is best seen inFIGS. 3-7, and takes the form of a piston pump50. The piston pump50has a main cylindrical housing52made of light-weight, low-wear material that reciprocatively mounts a piston54. The piston54is made of high-inertia material, such as solid steel, and is biased by a spring56. The piston54is caused to reciprocate in the cylinder due to vertical and lateral accelerations imposed upon the traction motor by rail irregularities encountered during normal operation. The reciprocation of the piston54causes oil in the oil reservoir12to be drawn in through the inlet valve42′ and output through the output valve42″ to the wick face36′ (FIG. 2). Movement of the piston54in a first direction against the spring56, which direction is to the right when viewingFIG. 3and, as explained above, is caused by lateral and vertical acceleration forces acting on the piston due to rail irregularities, causes oil droplets to be taken in through inlet valve42′, and movement in the opposite direction via the biasing spring56forces the oil out through the outlet valve42″, which outward movement is to the left when viewingFIG. 3.

Each of the inlet valve42′ and outlet valve42″ incorporates a ball check60,62, as best seen inFIGS. 5 and 6, respectively. The inlet valve42(FIG. 5) is provided with an outer cap64formed with an inlet hole, and defines an interior seat64′ for the ball60, which ball60is normally biased outwardly against the seat64′ by a spring66to close off the inlet hole of the cap64. The interior of the valve housing also defines passages68′ which permit the oil to bypass the ball check valve when the ball is unseated. The interior of the valve housing defines limit stops68against which the ball60abuts during its inward movement when the piston54moves during its intake stroke, as described hereinabove. The outlet valve42″ (FIG. 6) operates oppositely to that of the inlet valve, and is provided with an inner seat70against which the ball check62is seated during the piston intake-stroke for closing off the outlet of the pump, which ball is biased against the seat70by a spring72. During the discharge stroke of the piston54, the ball62is forced outwardly against the force of the spring72, thereby opening and allowing oil to be pumped out through the outlet valve and to the wick face36′ via the outlet tube46described hereinabove.

Referring now toFIGS. 8-10, there is shown a modification80of the first embodiment of the lubricating system of the invention in which the passive inertia-activated slosh pump ofFIG. 3is incorporated as part of a splash sleeve. The modification80utilizes a piston-type pump assembly82like that ofFIGS. 3-7but which is mounted to a splash sleeve84incorporating a plurality of reservoir-pockets or louvers86which are used for collecting oil that has been splashed during normal operation of the locomotive, as described in detail in above-mentioned copending application Ser. No. 11/284,635, which application is incorporated by reference herein. The splash sleeve84is mounted to the lower free end portion36″ (FIG. 2) of the felt wick36positioned in the oil-reservoir12, and defines a hollow interior volume that telescopingly receives therein the lower end of the felt wick. The piston-type pump assembly82is similar to the piston-pump assembly ofFIGS. 3-7, and includes a pump inlet valve82′ having a ball check and a pump outlet valve82″ having a ball check. Owing to the mounting of the pump assembly82to the lower end of the splash sleeve84, the inlet valve82′ is substantially deeply submerged in the oil-reservoir12, so that an inlet tube, such as the inlet tube44of the pump assembly42ofFIGS. 3-7, is not required.

Projecting from the main housing of the pump assembly82is the pump outlet valve82″ from which projects an outlet-tube88having an upper outlet-opening88′. The outlet valve82″ projects interiorly through the splash sleeve84and into the interior of the lower end portion of the wick lubricator, as seen inFIG. 8. An appropriately placed and sized opening is formed in the housing of the splash sleeve84through which the outlet valve82″ projects interiorly of the wick lubricator, with a juxtapositioned portion of the wick lubricator pad being cut out in order to accommodate the outlet-valve82″. The outlet-tube88is located interiorly of the wick-holder, and extends or runs vertically upwardly along the interior or center of the central wick-lubricator pad, with the outlet-opening88′ thereof terminating at the upper wick-face36′ of the wick pad36. The outlet-tube88assumes the same shape or curvature as that of the wick lubricator itself. Preferably, a cavity or reservoir90is formed adjacent, and in close proximity, to the upper wick-face36′ into which the outlet-opening88′ of the outlet-tube88feeds, so that oil delivered through the outlet-tube88may be temporarily stored therein for providing a more consistent and optimized lubrication of the wick-face36′.

The inlet-valve82′ with ball check of the pump assembly82of the modification80ofFIGS. 8 and 9may, alternatively, like the outlet-valve82″, be located interiorly of the lubricating wick pad, as seen inFIG. 11. In this case, the inlet-valve82′ extends substantially horizontally from the main housing of the pump assembly82, and into the interior of the wick pad juxtapositioned thereat. The intake opening of the inlet-valve82′ extends to, and cooperates with, an interiorly-located pocket or cavity92that is formed in the interior of the lower end portion of the wick, by which oil is collected for supplying the intake opening of the inlet-valve82′.

Whether the outlet valve82″, or both the outlet valve and inlet valve82′ project interiorly of the splash sleeve92, appropriately-situated cutouts are provided in the lower portion36″ of the felt wick36in order to accommodate their interior protrusion. With regard to the outlet tube88, it preferably extends between the two layers of the conventional felt wick36, as would evident to one of ordinary skill in the art. The lower end portion36″ of the felt wick is also provided with a opening or void to allow for the sloped lower portion88″ of the outlet tube88to connect to the outlet valve82″.

Referring now toFIGS. 12 and 13, there is shown a second embodiment100of the improved wick-lubricant delivery system for increasing lubricant flow to the face of the wick used to lubricate an axle-journal surface supported in a locomotive traction-motor friction support bearing. In this embodiment, the passive inertia-activated slosh pump is a diaphragm pump102instead of the piston-type pump of the first embodiment. The diaphragm pump102consists of a housing104vertically mounted to, and below, the wick-carrier assembly via mounting bracket106, which housing defines an interior cavity for storing oil being pumped. Mounting bracket106positions the pump assembly below the spring22. The housing104is provided with an inlet ball-check valve108that is mounted to a bottom open end110′ of an oil-pickup tube110. The upper end110″ of the tube110is connected to a tubular intake114formed in the housing104of the diaphragm pump102. The housing104also has an outlet opening112to which is coupled an outlet ball-check valve116to which is connected a pump-discharge tube118similar to the tube46of the first embodiment ofFIGS. 1-7, which discharge tube118is located exteriorly of the wick-holder, with the upper outlet-opening thereof terminating at the wick-face of the felt wick, so that droplets of oil taken up by the pump are delivered to the wick face36′ during normal operation.

Interiorly of the housing there is located a conventional diaphragm120that is biased upwardly by a spring122. Affixed to the upper surface of the diaphragm120is a flexible mounting stem or connector124which mounts a downwardly-projecting, elongated flexible cable or connector126. The connector126projects exteriorly of the housing104via a lower opening formed in a lower section104′ of the housing. To the bottom end of the flexible connector126there is connected an inertial mass130, which, together with the flexible connector126, serves as a pendulum. Movement of the inertial mass130, because of the lateral and vertical acceleration forces acting thereon due to rail irregularities, causes deflections of the spring122and diaphragm120. The deflection of the diaphragm120in the downward direction against the spring122causes oil droplets to be taken in by oil inlet108, while the upward deflective movement thereof in the opposite direction via the biasing spring122forces the oil out through the outlet valve116.

The diaphragm pump102of the second embodiment ofFIGS. 12 and 13may also be mounted to a splash sleeve, in a manner similarly to that of the inertial piston pump of the first embodiment shown ofFIGS. 8-11. In addition, it is within the scope and purview of the invention that, instead of a splash sleeve being used to mount the inertial pump to the lower end portion of the central lubricating wick, different mounts or sleeves may be used, whether they mount the passive inertia-activated slosh pump to the central lubricating wick or to the wick bracket assembly proper. In addition, although it is preferable that the discharge tube of the passive inertia-activated slosh pump extend at least partially interiorly and through the central lubricating wick for discharging oil droplets at the wick face when the inertial pump is mounted to the splash sleeve or other mount, it is possible to run the discharge tube exteriorly.

In all of the above-described embodiments, the slosh pump works in parallel, or in conjunction, with the capillary action of the wick in order to deliver oil to the interface between the wick face and the journal surface. It is also envisioned that, if the delivery rate of the slosh pump is equal to or greater than that of the wick, a modification may be employed where the wick tail is cut off, with the sustained oil delivery being dependant upon the slosh pump alone. In this modification, the wick serves as a reservoir and part of the delivery system.

In yet another modification shown inFIG. 13, with the volume of oil delivered to the journal surface no longer dependent upon the cross-sectional area of the wick body and face, the wick may be eliminated altogether in favor of the inertial pump oil-delivery system of the invention routed to a simple intake hole or lubricating opening128formed through the bearing18and its liner, whereby the entire surface-interface lubrication of the journal surface37is accomplished by the slosh pump102ofFIG. 12, for example, with the slosh pump102being mounted directly to the carrier assembly14, or otherwise mounted to the bearing axle cap16, with its discharge tube118feeding directly into the intake hole or opening128. In this embodiment, the elimination of the wick would also allow replacement of the wick window in the bearing cap and bearing liner with the opening128. Instead of the diaphragm pump102, the piston-type pump ofFIG. 1may also be used alone in accordance with this embodiment.

In all of the above-described embodiments and modifications, as a result of the increased oil-saturation of the wick, optimized amounts of oil are delivered to the axle-journal surface-area. This optimized amount of oil saturation and enhanced oil delivery provide better protection against axle-journal bearing failure in the event that a locomotive is used with diminished axle-journal oil levels. In addition, the temperature of the oil is reduced and the viscosity increased, to thus increase the rated load-capacity of the bearing, and to thus increase the tolerance of the bearing to minor surface imperfections. The optimized wick-saturation and oil delivered to journal lowers the wick-face temperature and reduces the rate of wick-face glazing, thereby extending the life of the wick. This enhanced wick-saturation and oil delivered to the journal also limit the ingress of external contaminants into the loaded journal areas, thereby reducing wear and extending the life of the bearings.

The particular type of inlet and outlet valves used in each version of the slosh pump may vary from that disclosed hereinabove. It is, also, preferable, though not requisite, that the inlet valve of each version of the slosh pump be similar in construction and of the same type as that of the outlet or discharge valve thereof.

While specific embodiments of the invention have been shown and described, it is to be understood that numerous changes and modifications may be made therein without departing from the scope and spirit of the invention.