BACKGROUND OF THE INVENTION
The present invention is directed to a railway locomotive traction motor and, in particular, to the friction support or sleeve bearing by which the traction motor is partially supported on the axle of the railway truck mounting the underside of the locomotive, and, in particular, the invention is directed to providing additional lubrication.
A conventional railway locomotive pinion-end (PE) traction-motor support bearing, such as that disclosed in U.S. Pat. No. 5,038,631, is shown in FIGS. 1 and 4, which FIGS. 1 and 4 show the half of the support bearing 10 that contains the window 12 for passing a lubricating wick. For best overall performance and life of the traction-motor support bearing, the load zones for loading the truck axle should be centered. This is so in order that the lubricating wick (not shown) entering the interior of the bearing via the wick window or opening 12 lubricates all contacting surface-areas, which lubricating wick contacts the axle journal through the window. In addition, both load zones should be contained within the total axial dimension of the wick if possible, again in order to ensure the best possible lubrication. Each traction-motor sleeve bearing has two load zones, an upper one and a lower one, and these tend to be heaviest around 25° from vertical because of commonly-used 25° gear-tooth pressure angle. Both load-contact patterns can be seen in the window half 10 of the PE bearing with the upper load pattern above the lubricator access-window and the lower load pattern below the window. Ideally, both upper and lower load contact-patterns should be centered at mid-length of the window, in order that the wick lubricator provides the best possible lubrication. Further, both load contact-patterns should be contained within the total axial dimension or limits of the wick lubricator if possible, again to ensure the best possible lubrication.
The lubricating wick of the conventional sleeve bearing shown in FIGS. 1 and 4 enters the bearing from the lubrication sump through a cast opening in the axle cap, which is aligned with the window or opening 12 in the bearing liner. This opening 12 is centered axially on the journal and the wick protrudes through this opening to contact the axle at a position approximately 20°-30° below a horizontal line passing through the axle gear and pinion center lines. The sleeve bearing 10 also has a flange wick 16 for lubricating the flange-end 20.
The axial length of the preferred journal-to-liner contact area is defined by the axial length of the wick. The bearing liners are machined in such a way as to relieve the liners so that axle-journal contact under normal loads remains in the wick-wetted axial area 14. In many traction motor support bearings, however, the envelope available for supporting the journal is significantly longer in the axial direction than the wick and the length of wetted area.
Pinion-end sleeve bearing load ratings are frequently limited by the axial length that can be reliably lubricated by the lubrication delivery system. If lubrication can be assured beyond the axial dispersion of conventional support bearings, that additional length may become useful for supporting the axle journal. By reducing the unit loading of the original journal and thereby increasing the load capacity, or by reducing the required viscosity, surface finish, and other parameters affecting wear rate the reliability, is improved.
SUMMARY OF THE INVENTION
It is a primary objective of the present invention to provide an improved sleeve bearing for a locomotive traction motor that provides additional lubricated areas in the axle bore over and above that of the conventional central wick currently used.
According to the present invention, the sleeve bearing is provided with the ability to provide additional lubrication to the lateral areas beyond the width of the main supply wick by the addition of additional wicks one on either axial side of the central wick or by incorporating passageways near the 6:00 location on either axial side capable of communicating with the oil accumulated in the oil flinger grooves and taking advantage of the oil-flinger rotating lift capability and lateral movement within the bearing lateral clearances for providing additional lubrication and for extending the envelope of the wetted area available for supporting the truck-axle journal in the axial direction.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more readily understood with reference to the accompanying drawings, wherein:
FIG. 1 is a longitudinal, vertical cross-section view of a window-half of a prior art sleeve bearing using one central lubricating wick;
FIG. 2 is a longitudinal, vertical cross-section view of a first embodiment of the sleeve bearing of the invention employing the additional lubricating wicks of the invention, one on the inboard end and one on the outboard end of the sleeve bearing;
FIG. 3 is a longitudinal, vertical cross-section view of a second embodiment of a sleeve bearing employing the additional lubricating wicks, one on the inboard end and one on the outboard end of the sleeve bearing where the bearing employs flinger grooves;
FIG. 4 is a partial longitudinal cross-section view showing a prior-art sleeve bearing having a flange wick at the flange-end, or outboard end, of the sleeve bearing;
FIG. 5 is a partial longitudinal cross-section view similar to FIG. 4 but showing the sleeve bearing without flinger grooves with the additional wicks of the embodiment of FIG. 2;
FIG. 6 is a partial longitudinal cross-section view similar to FIG. 5 but the showing the sleeve bearing utilizing flinger grooves with the additional wicks of the embodiment of FIG. 3;
FIG. 7 is a partial longitudinal cross-section view similar to FIG. 3 and showing a third embodiment of the invention where the sleeve bearing, instead of having the additional wicks of the first and second embodiments, is provided with oil recirculation passageways originating near the 6:00 position, which passageways deliver oil from the flinger/collection grooves and redistribute a portion of the oil to the lateral areas of the bearing liner beyond the wick window;
FIG. 8 is a partial longitudinal cross-section view similar to FIG. 5 of a fourth embodiment of the invention of a sleeve bearing without flinger rings or oil-collection grooves, with the outboard supplemental wick of the invention being connected to the flange wick; and
FIG. 9 is an isometric view showing a fifth embodiment of the invention utilizing both oil-collections grooves and flinger grooves at the inboard and outboard ends, and shows a pocket or recess for mounting therein an supplemental or auxiliary wick.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings in greater detail, and to FIGS. 2 and 5 for now, there is shown a first embodiment of the railway-locomotive traction motor friction support or sleeve bearing of the invention and indicated generally by reference numeral 30. In this first embodiment, the invention is embodied in a friction support bearing that does not employ flinger grooves. Flinger grooves mount flinger rings which, when employed, help to redistribute the oil back to the oil reservoir and reduce oil, loss, as disclosed in U.S. Pat. No. 3,905,659. The sleeve bearing 30 is provided with a conventional central wick window 12, as explained hereinabove with regard to FIGS. 1 and 4, and, in addition, at least two supplemental or auxiliary wicks, one wick 32 at the outboard end and one wick 34 at the inboard end. The supplemental wicks 32, 34 are oriented at 6:00 O'clock when viewing FIG. 2. The outboard wick 32 is combined with the currently-used flange wick 16, also explained above with reference to the prior-art bearing of FIGS. 1 and 4. The wicks 32, 34 are lubricated via lateral flow oil collection grooves 36, 38, respectively, which are used, as in conventional manner, for collecting oil, as explained in U.S. Pat. No. 4,229,056. The provision of these additional wicks 32, 34 extend the effective length of the wetted area of the bearing to the areas encompassed by areas A, B and C in FIG. 2, to thus extend the lubricated surface from the hitherto prior-area area A, to thus make significantly longer in the axial direction the available wetted area for contact by the truck-axle journal. To ensure of the additional envelope length available, the simple reliable oil supply system 36, 38 is used. This system collects the lateral oil discharge from the loaded central region serviced by the conventional central wick and delivers the oil to those journal areas beyond the main wick wetted axial area via these additional wicks 34, 36. Thus, these oil collection grooves 36, 38 also serve the additional function of providing for this additional lubrication of the extended contact areas B and C.
The supplemental wick 32 is, in the preferred embodiment, narrower than the corresponding flange wick 16, although, if necessary, it may be the same or even greater n width. Each supplemental wick 32, 34 has a first overlapping portion 32′, 34′, respectively, that is received within the interior of a respective channel 36, 38, and a main longitudinal portion or section 32″, 34″ extending longitudinally axially in a direction toward the center of the friction bearing. With each overlapping portion 32′, 34′ positioned in the interior of the respective groove, each groove 36, 38 acts as a sump or reservoir for the additional wicks 32, 34. Furthermore, the main body portion 32″, 34″ of each wick 32, 34 is received or mounted in a recess or pocket 36′, 38′, respectively, formed in the interior shell of the friction bearing, in the manner shown in FIG. 8. Each pocket has a depth less than that of the thickness of the respective additional wick 32, 34, so that each wick 32, 34 projects or protrudes out from the respective pocket, and interiorly toward the axle journal mounted in the bearing, for contact against the juxtapositioned surfaces of the journal located within the lateral extent of the above-mentioned contact areas B and C.
Each additional wick 32, 34 is made of conventional material providing capillary effect, such as that of which the conventional central wick is made or that of which the flange wick is made. As explained above, the width of each additional wick is preferably less than the width of the flange wick, although such does not preclude the same or greater width. It is also noted that corners 36″, 38″ of the pockets are rounded to ensure that the wicks are maintained therein. The wicks may be made of felt or composite materials to optimize retention and delivery. The supplemental wicks may be retained by adhesives or by geometry of the machined pockets which also act as reservoirs in combination with the wick geometry.
Referring now FIGS. 3 and 6, there is shown a second embodiment of the sleeve bearing of the invention, which is directed to applying the invention to a friction bearing provided with flinger grooves, but without the oil collection grooves 36, 38 of the first embodiment of FIGS. 2 and 5. The friction support bearing of this embodiment is indicated generally by reference numeral 40, and, as shown, utilizes conventional flinger grooves 42, 44. In this embodiment, the flinger grooves 42, 44, in addition to serving their conventional function of mounting the flinger rings, as disclosed in U.S. Pat. No. 3,905,659, also serve the function of the lateral-flow oil-collection grooves for the additional wicks 52, 54. The additional wicks 52, 54 are oriented at 6:00 O'clock when viewing FIG. 3, as in the first embodiment. Since the flinger grooves 42, 44 mount the flinger rings, a separate conventional flange wick 56 is conventionally mounted. In all other respects, the additional wicks 52, 54 are the same as the wicks 32, 34 of the first embodiment, and are mounted in pockets or recesses similar to those shown in FIG. 8 discussed below.
Referring to FIG. 7, there is shown a third embodiment 60 of the invention in which, instead of using the additional wicks of the first two embodiments to lubricate the additional surface contact areas B and C, oil-flow passageways 62, 64 forming a V-shape are provided on the flange or outboard end, and oil-flow passageways 66, 68 forming a V-shape are provided on the inboard end. These passageways are oriented approximately at 6:00 O'clock when viewing FIG. 7. Unlike the first two embodiments, the friction bearing 60 is provided with both oil-collection grooves 70, 72 and flinger grooves 74, 76, in a manner disclosed in U.S. Pat. No. 4,229,056. Each passageway is opens into the interior of a respective flinger grooves 74, 76 for fluid communication therewith, and, thus, effectively serve as oil-flow extension grooves of the flinger grooves. The V-shaped passageways 62, 64, and the V-shaped passageways 66, 68 form an acute angle therebetween, as seen in FIG. 7, and preferably is in the range of between 15 degrees to 45 degrees, although this is not meant to be limiting. This embodiment takes advantage of the proven collection and return system of the conventional inboard and outboard ends of the bearing liner by using the flinger rings to cause oil to flow into the oil recirculation grooves and hence to be delivered to the bearing lateral areas both at the inboard and outboard ends of the bearing liner beyond that wetted by the main delivery wick. While two such passageways have been shown which are V-shaped, more than two such passageways may be employed without a V-shaped configuration.
Referring to FIG. 8, there is show a fourth embodiment 80 of the invention in which no flinger grooves or oil collection grooves are included in the friction bearing 80. In this case, the outboard supplemental wick 82 is connected to the flange wick 84 to form one continuous wick. The inboard supplemental wick 86 is the same as in the first two embodiments. Since the wicks are located at the 6:00 operating position, they would, therefore, receive their lubrication as a result of the natural gravity drainage accumulation from the journal wetted surfaces any time the axle would be at rest. During rotation, the normal supply wick delivers a band of oil on the axle. The supplemental or auxiliary wicks inboard ends would overlap this wetted band and take a portion of this oil to extend the wetted band width.
Referring to FIG. 9, there is shown a fifth embodiment 90 which incorporates both flinger grooves and oil-collection grooves. The supplemental or auxiliary wicks 92 are received in pockets or recesses 94 formed in the interior shell of the friction bearing. Each pocket has a depth less than that of the thickness of the respective additional wick, so that each wick projects or protrudes out from the respective pocket, and interiorly toward the axle journal mounted in the bearing, for contact against the juxtapositioned surfaces of the journal located within the lateral extent of the above-mentioned contact areas B and C. Each pocket 94 has an open end 96 that is in fluid communication with the interior of a respective flinger groove 98 for lubricating the respective supplemental or auxiliary wick in a manner similar to the embodiment of FIG. 3.
Use of the supplemental or auxiliary wicks of the present invention allows reduced-width flinger grooves as compared to the prior art friction support bearings, and also allows for the flingers grooves to be moved farther away from the center wick. Also, it is also possible to have a version of the invention where the flinger grooves and the outboard oil-collection groove are eliminated, which would extend the usable load-carrying width approximately one more inch.
In one prototype of the friction support bearing of the invention for use with a General Electric 752 AG traction motor, the width of the crowned load-bearing surface area was increased to approximately 5.18 in. as compared to 3.76 in. for the conventional bearing. Also, each supplemental or auxiliary wick was approximately 1.25 in. in length taken in the direction parallel to the annular flinger groove. and 0.81 in. in width taken in the axial bearing direction, with the thickness thereof depending upon proper contact with the axle journal juxtapositioned thereat, and was received in a pocket or recess of width of 0.81 inch and length of 1.25 inches, with the pocket having rounded corners of radius 0.312 in. similar to the rounded corners of the supplemental or auxiliary wick. In addition, the open end 86 was 0.626 in.
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
Patent Application
20060013518
