US3662858A

US3662858A - Self-purging lubricant reservoir

Info

Publication number: US3662858A
Application number: US67513A
Authority: US
Inventors: David W Peterson
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1970-08-27
Filing date: 1970-08-27
Publication date: 1972-05-16
Anticipated expiration: 1989-05-16
Also published as: CA927296A

Abstract

In a preferred embodiment, the axle bearing caps of a railway locomotive traction motor include oil containing sumps from which lubricating oil is delivered by wick means to lubricate the axlecarrier motor support bearings. Overflow conduit means are provided which connect with an interior portion near the bottom of the sump and extend upwardly to an overflow outlet that is open to atmosphere and located at approximately the desired maximum oil level in the sump. When oil is added to the sump in excess of that required to reach the maximum level, the excess volume is forced from the bottom of the sump, out through the overflow conduit, thereby removing water and other contaminating liquids which are heavier than oil and settle to the bottom of the sump.

Description

Unite States Patet 51 May to, 1972 Peterson [54] SELF-P GING LUBRICANT RESERVOIR [72] Inventor: David W. Peterson, Oak Brook, 1]].

[73] Assignee: General Motors Corporation, Detroit,

Mich.

[22] Filed: Aug. 27, 1970 [21] App]. No.: 67,513

[52] U.S.Cl. ..l84/103 12,210/532 [51] Int. Cl .B01d 17/02, FOlm 11/12 [58] Field of Search ..210/532, 533; 184/103 R [56] References Cited UNITED STATES PATENTS Primary ExaminerManuel A. Antonakas Attorney-J. L. Carpenter and Robert J. Outland [5 7] ABSTRACT In a preferred embodiment, the axle bearing caps of a railway locomotive traction motor include oil containing sumps from which lubricating oil is delivered by wick means to lubricate the axle-carrier motor support bearings. Overflow conduit means are provided which connect with an interior portion near the bottom of the sump and extend upwardly to an overflow outlet that is open to atmosphere and located at approximately the desired maximum oil level in the sump. When oil is added to the sump in excess of that required to reach the maximum level, the excess volume is forced from the bottom of the sump, out through the overflow conduit, thereby removing water and other contaminating liquids which are heavier than oil and settle to the bottom of the sump.

1 Claim, 7 Drawing Figures PATENTEUmnsm 3.6621358 SHEET 1 OF 2 sic B Y fia V/Q) i llfi ersan ATTORNFY PATENTEDMAY I6 SHHZT 2 OF 2 INVENTOR.

[([Hzerwn ATTORNEY SELF-PURGING LUBRICANT RESERVOIR BACKGROUND OF THE INVENTION This invention relates to self-purging lubricant reservoirs and, more particularly, to reservoirs having means for removing heavier-than-oil liquid contaminants through an overflow system. In its more particular aspects, the invention relates to oil retaining axle bearing caps for railway vehicle traction motors and like applications wherein there is substantial exposure to the possibility of contamination of an oil reservoir by the entry of water during normal use.

It is known in a railway locomotive to provide electric traction motors mounted in the trucks and having one side thereof supported by axle bearings carried on the axle of the associated pair of drive wheels. To lubricate the axle bearings, it is known to provide removable axle bearing caps, each of which contains a covered oil reservoir or sump and wick means for drawing the oil from the reservoir to the axle journals. Filler opening means are commonly provided and may be located at approximately the desired maximum oil level in the sump to prevent overfilling. Separate overflow means may also be provided or the filler means may act as an overflow to maintain the maximum oil level, should there by any additional volume of fluid added by external leakage of contaminants, such as water. A drain plug is normally provided for draining contaminants from the system or for removing and changing the lubricant, if desired.

Since the traction motor bearing axle caps are located underneath the locomotive in positions exposed to the weather, there is a substantial problem of contamination by water seepage into the bearing cap reservoirs. This occurs due to operation in rain and snow, as well as from locomotive washing operations wherein high pressure water jets may be used to clean dirt from the locomotive and its running gear. Periodic maintenance procedures for the axle bearing caps thus require not only that additional oil be added from time to time to make up for that used in lubricating the bearings, but also that accumulated water be occasionally drained by removal of the drain plug. If the latter step is overlooked for an extended period, there is danger that accumulated water may rise high enough in the sump to contaminate the wick and starve the bearings for oil. Since water settles to the bottom of the reservoir, the fact of its presence in the oil sump is not noticeable during servicing if this is limited merely to adding oil through the filler openings.

SUMMARY OF THE INVENTION The present invention provides overflow means for purging water and other heavier-than-oil liquid contaminants from an oil sump during the routine operation of filling the sump with oil. As applied to a locomotive traction motor axle bearing cap, the overflow means comprises a conduit which connects a point adjacent the interior bottom of the oil sump with an overflow outlet open to atmosphere and located at a level approximately equal to the desired maximum oil level in the sump. Such an overflow arrangement, which may take many physical forms, operates, when the oil sump is filled above its maximum level, to drain liquid from the bottom of the sump, thereby draining off any water or other heavy liquid contaminants which have settled to the bottom. In this way, the removal of contaminating water may be accomplished during the step of replenishing the oil level in the axle bearing reservoir by merely adding oil until all the water is removed from the bottom of the sump and oil is seen to flow from the overflow conduit.

These and other advantages of the present invention will be more clearly understood from the following description of several alternative embodiments of the invention, taken together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a pictorial view showing a railway locomotive traction motor as secured to its associated drive wheels and including traction motor support bearing axle caps having oil reservoir overflow means according to the present invention;

FIG. 2 is a cross-sectional view taken in the plane indicated by the line 2-2 of FIG. 1 and showing the interior detail of one of the axle caps;

FIG. 3 is a cross-sectional view of the overflow conduit means utilized in the embodiment of FIGS. l and 2;

FIG. 4 is a cross-sectional view of an axle cap arrangement utilizing an alternative embodiment of overflow conduit means;

FIG. 5 is a partial cross-sectional view of an axle cap utilizing yet another alternative embodiment of overflow conduit means;

FIG. 6 is a cross-sectional view of an axle cap arrangement utilizing still another embodiment of overflow conduit according to the invention; and

FIG. 7 is a cross-sectional view of the overflow conduit arrangement of the embodiment of FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGS. 1-3 of the drawings, numeral 10 generally indicates an electric traction motor for a railway locomotive. Traction motor 10 is drivingly connected through gears, not shown, to an axle 12 on the ends of which are secured a pair of flanged driving wheels 14. Drive wheels 14 and axle l2'also support one side of the traction motor 10 by means of plain bearings 16 which are secured around the axle by the traction motor frame 18 and a pair of axle bearing caps 20, secured to the frame 18 by means of bolts 22.

As best shown in FIG. 2, bearing caps 20 include an enlarged oil sump 24 which is closed by a cover 26 and is adapted to contain a body of lubricating oil 28 having a predetermined desired maximum level. Cover 26 supports, by means of a bracket 30, a wick 32 which may be made of felt or other suitable material. Wick 32 is supported with one end extending into the body of oil 28 and the other end engaging the journal surface 34 of axle 12 so that oil is drawn by capillary action up through the wick and deposited on the axle journal. An opening 36 is provided in the traction motor support hearing 16 to permit the wick 32 to extend therethrough.

Each axle bearing cap 20 is also provided with a filler opening 38 closed by a dust cap 40 and located in a side wall of the sump. A drain opening 42 is also provided in the bottom wall of the sump.

In accordance with the present invention, each axle cap 20 is also provided with an overflow conduit assembly 44 best shown in FIG. 3. Conduit assembly 44 comprises a threaded plug 46 having a central opening 48 in which is secured a standpipe 50. A second standpipe 52 is also secured to the plug 46 and concentrically disposed in spaced relation around standpipe 50, extending axially beyond standpipe 50 for a substantial distance. An inlet opening 54 is provided in the standpipe 52 at a point near its connection with the threaded plug 46.

Conduit assembly 44 is adapted to be received within the sump drain opening 42, with plug 46 threadably secured within the opening 42 so that

standpipes

50, 52 extend vertically upwardly within the sump. With this arrangement, when oil is added to the sump through filler openings 38, the oil level reaches a maximum height equal to the height of the inner standpipe 50, the oil flowing through the inlet opening 54 and between the standpipes up to the inner standpipe level. When additional oil is added to the reservoir, the excess flows over the top of standpipe 50 and drains therethrough out through the central opening 48 in the threaded plug 46. If there is any water in the sump at this time, it will have settled to the bottom, since it is heavier than oil and will enter the inlet opening 54 and be forced out through the overflow conduit 44 in the manner just described. The extended height of the outer standpipe 52 prevents the draining of oil from the top of the sump and requires the outlet flow to pass through opening 54 at the bottom of the standpipe 52.

Referring now to FIG. 4 of the drawings, there is shown an alternative embodiment of axle bearing cap arrangement which is similar to that just described, differing only in the type of overflow conduit means utilized. In this embodiment, an outlet opening 56 is provided in a sidewall of the bearing cap 20 at a point near and slightly below the filler opening 38. An overflow tube 58 extends downwardly through opening 56, having its open lower end adjacent the bottom of the oil sump 24. The upper end of the tube 56 is bent so that the opening faces downwardly to reduce the possibility of water being splashed into the tube and entering the sump 24 in this manner.

In FIG. of the drawings, another embodiment of overflow conduit means according to the invention is disclosed. In this embodiment the drain opening 42 of the bearing cap sump is fitted with a plug 60 having a downwardly extending fitting portion 62. Secured to the fitting portion 62 by means of a clamp 64 is one end of a formed hose 66 which extends upwardly, externally of the oil sump, to a point approximating the desired maximum oil level within the sump. The upper end of the hose is bent so that it opens downwardly to reduce the possibility of water entering the sump through the hose.

ln FIGS. 6 and 7 still another embodiment of overflow means according to the invention is disclosed. As shown in FIG. 6, bearing cap 20 is provided with an alternative filler opening 68 located in the cover 26 and closed by the usual dust cap 40. In this arrangement, the normal filler opening 38 is replaced by an outlet opening 70 which is disposed an overflow conduit assembly 72 of the type shown in FIG. 7. Assembly 72 comprises a straight tube 74 supporting a threaded bushing 76 and a cap 78. A plurality of circumferentially spaced outlet holes 80 are provided near one end of the tube, the holes being shielded by the cap 78 which is open axially of the tube in a downwardly facing direction, as installed. Conduit assembly 72 is installed within opening 70 with the threaded bushing fixed within the opening so that tube 74 extends interiorly of the sump, having its open bottom adjacent the bottom of the sump. Openings 80 are located exteriorly of the sump and are protected by the cap 78 so as to prevent the splash of water into the tube assembly.

Operation of the embodiments of FIGS. 4-7 is substantially identical, in that filling of a sump with oil above the level of the upper end of its overflow conduit causes fluid in the bottom of the sump to flow out through the conduit. In this way, water collecting in the bottom of the sump is purged and a desired maximum oil level is maintained.

The above-described embodiments are intended to be illustrative only and are not meant to limit the scope of the invention as defined in the following claims.

Iclaim:

1. An oil retaining bearing cap for a railway vehicle drive motor having an oil lubricated axle bearing, said bearing cap comprising a covered sump for retaining therein a supply of oil,

a filler opening above the normal oil level for adding oil to said sump, said filler opening being provided with an openable cover,

an overflow conduit associated with said bearing cap and having upper and lower ends and an impervious wall intermediate said ends, said upper end having an overflow outlet at approximately the desired level of oil in said sump, said outlet being open to atmosphere and connecting with the exterior of said sump, and said lower end being open to a lower portion of said sump adjacent the bottom thereof to receive fluids from said sump lower portion,

a drain opening in the bottom of said sump, said overflow conduit comprising a pair of standpipes secured around said drain opening in concentric spaced relation within said sump, the inner one of said standpipes being sealed around said opening and extending upwardly to the desired maximum or level and the outer one of said standpipes having an opening adjacent its bottom end and extending upwardly to a level above the inner standpipe, whereby the addition of an excessive volume of fluid to said sump will cause a volume of fluid to be forced from the lower portion of said sump into said overflow conduit and out through said overflow outlet, thereby selectively removing from the sump water which may have settled to the bottom thereof while maintaining the desired maximum oil level in said sump, said standpipes being both secured to a threaded plug to form an assembly removable from said bearing cap to permit complete draining of the sump.

Claims

1. An oil retaining bearing cap for a railway vehicle drive motor having an oil lubricated axle bearing, said bearing cap comprising a covered sump for retaining therein a supply of oil, a filler opening above the normal oil level for adding oil to said sump, said filler opening being provided with an openable cover, an overflow conduit associated with said bearing cap and having upper and lower ends and an impervious wall intermediate said ends, said upper end having an overflow outlet at approximately the desired level of oil in said sump, said outlet being open to atmosphere and connecting with the exterior of said sump, and said lower end being open to a lower portion of said sump adjacent the bottom thereof to receive fluids from said sump lower portion, a drain opening in the bottom of said sump, said overflow conduit comprising a pair of standpipes secured around said drain opening in concentric spaced relation within said sump, the inner one of said standpipes being sealed around said opening and extending upwardly to the desired maximum oil level and the outer one of said standpipes having an opening adjacent its bottom end and extending upwardly to a level above the inner standpipe, whereby the addition of an excessive volume of fluid to said sump will cause a volume of fluid to be forced from the lower portion of said sump into said overflow conduit and out through said overflow outlet, thereby selectively removing from the sump water which may have settled to the bottom thereof while maintaining the desired maximum oil level in said sump, said standpipes being both secured to a threaded plug to form an assembly removable from said bearing cap to permit complete draining of the sump.