Rail road car truck and members thereof
A rail road freight car truck has a truck bolster and a pair of side frames, the truck bolster being mounted transversely relative to the side frames. The mounting interface between the ends of the axles and the sideframe pedestals allows lateral rocking motion of the sideframes in the manner of a swing motion truck. The lateral swinging motion is combined with a longitudinal self steering capability. The self steering capability may be obtained by use of a longitudinally oriented rocker that may tend to permit resistance to deflection that is proportional to the weight carried across the interface. The truck may have auxiliary centering elements mounted in the pedestal seats, and those auxiliary centering elements may be made of resilient elastomeric material. The truck may also have friction dampers that have a disinclination to stick-slip behavior. The friction dampers may be provided with brake linings, or similar features, on the face engaging the sideframe columns, on the slope face, or both. The friction dampers may operate to yield upward and downward friction forces that are not overly unequal. The friction dampers may be mounted in a four-cornered arrangement at each end of the truck bolster. The spring groups may include sub-groups of springs of different heights.
1. At least one member of a railroad freight car truck that member having a first self-steering apparatus fitting, said at least one member comprising at least one of:
(a) a bearing adapter for mounting to a casing of a bearing on a rail road car truck wheelset, said bearing adapter being for use in combination with at least one other member having a second fitting of the self-steering apparatus, said at least one other fitting including at least a pedestal seat; said bearing adapter having a pair of axially spaced apart arches formed to seat on a cylindrical casing of a rail road freight car roller bearing having an axis of rotation, and first and second pairs of corner abutments, each pair of corner abutments be spaced to straddle respective ones of a pair of first and second opposed thrust lugs of a rail road freight car sideframe pedestal; said bearing adapter having a metal rolling contact engagement surface for orientation facing away from the wheelset when installed; and said bearing adapter rolling contact engagement surface has a fore-and-aft arcuate profile permitting rolling contact rocking of the wheelset bearing lengthwise relative to the sideframe; and
(b) a sideframe of a railroad freight car truck, said sideframe having a compression member, a tension member, a first sideframe column and a second sideframe column; said tension member, compression member, first sideframe column and second sideframe column defining bottom, top and sides of a sideframe window formed to receive an end of a freight car truck bolster; said sideframe columns having friction members operable to develop friction when the bolster moves relative to said columns; said tension member extending upwardly to meet said compression member at first and second ends of said sideframe, said sideframe having first and second sideframe pedestals at said first and second ends thereof respectively, each of said sideframe pedestals having a pedestal jaw, each said pedestal jaw including first and second opposed thrust lugs about which corner abutment pairs of a bearing adapter may seat; said pedestals each including a pedestal seat, one said pedestal seat being a first pedestal seat, said first pedestal seat being for use in combination with at least one other member having a second fitting of the self-steering apparatus, said at least one other member including at least a bearing adapter having a pair of axially spaced apart arches formed to seat on a cylindrical casing of a rail road freight car roller bearing, and first and second pairs of corner abutments, each pair of corner abutments being spaced to straddle respective ones of said opposed thrust lugs; said first pedestal seat having a metal rolling contact engagement surface for orientation toward the wheelset; and said metal rolling contact engagement surface of said first pedestal seat has a fore-and-aft arcuate profile permitting rolling contact rocking of the wheelset bearing lengthwise relative to the sideframe.
2. The subject matter of claim 1 wherein said at least one member having said first self-steering apparatus fitting is the bearing adapter of part (a) of claim 1 .
3. The subject matter of claim 2 wherein said bearing adapter rolling contact engagement surface is one of (a) a spherical surface; and (b) a surface having a curvature formed on a body of revolution having an axis parallel to the axis of the bearing.
4. The subject matter of claim 1 wherein said at least one member having said first self-steering apparatus fitting is the sideframe of part (b) of claim 1 .
5. The subject matter of claim 4 wherein said sideframe has a long dimension defining a longitudinal axis, and said metal rolling contact engagement surface of said first pedestal seat is one of (a) a spherical surface; and (b) a surface having a curvature formed on a body of revolution having an axis cross-wise to the longitudinal axis of the sideframe.
6. The subject matter of claim 1 wherein said rolling contact engagement surface having said fore-and-aft arcuate profile also has a cross-wise arcuate profile.
7. A combination of a first member according to claim 1 , and a mating second member, said second member having a mating second self-steering apparatus fitting having another metal rolling contact engagement surface orientable on installation to mate with said metal rolling contact engagement surface having said fore-and-aft arcuate profile, and, when installed in a railroad car truck and co-operatively engaged, said first fitting and said mating second fitting being operable to provide self-steering.
8. The combination of claim 7 further including a third member, said third member being a resilient member mountable in co-operation with at least one of (a) said first member, and (b) said second member; and said third member being operable to urge said rolling contact surfaces of said first and second members to a centered position relative to each other.
9. A combination of the bearing adapter of part (a), and the sideframe of part (b) of claim 1 , said bearing adapter and said first pedestal seat being matingly engageable on installation to permit fore-and-aft rolling contact rocking therebetween.
10. The combination of claim 9 wherein said first pedestal seat and said bearing adapter are also engageable to rock laterally in rolling contact with respect to one another.
11. The combination of claim 10 wherein the metal rolling contact engagement surface of at least one of (i) said bearing adapter and (ii) said first pedestal seat is formed on a compound surface.
12. The combination of claim 10 wherein any said rolling contact engagement surface includes a spherical portion.
13. The combination of claim 9 including at least a third member, said third member being a resilient member mountable to urge said bearing adapter and said first pedestal seat to a centered position relative to each other.
14. The combination of claim 13 wherein the bearing adapter has an end wall, and said third member is formed to seat between that end wall and a thrust lug of said first sideframe pedestal.
15. The combination of claim 13 wherein the bearing adapter has at least one end wall, and said third member has a first portion for seating adjacent said end wall, and a second portion at least partially overlying said bearing adapter, said second portion having a relief formed therein to accommodate rocking engagement of said bearing adapter with said first pedestal seat.
16. The member of claim 1 wherein said member is one of:
(i) the bearing adapter of part (a), and said metal rolling contact engagement surface is a rocker having both lengthwise and cross-wise radii of curvature; and
(ii) the sideframe of part (b), and said metal rolling contact engagement surface is a rocker having both lengthwise and cross-wise radii of curvature.
17. The member of claim 1 wherein said member is the bearing adapter of part (a) of claim 1 , for seating on a roller bearing that has first and second axially spaced apart roller bearing races enclosed within a casing, and said first and second arches are engageable with first and second end regions of the bearing casing, the bearing races being straddled between the arches; and a land for engaging the casing, said land extending between the arches and being relieved at locations above top dead center of the bearing races.
18. In combination, (i) the at least one member of claim 1 wherein said member is the bearing adapter of part (a); and (ii) a roller bearing, the bearing adapter being for seating on the roller bearing; wherein said bearing has first and second axially spaced apart roller bearing races enclosed within a casing, said bearing races being straddled between the arches of said bearing adapter; said bearing adapter has a land for engaging the casing, said land extending between the arches, said land having at least one relief, and said bearing adapter being mounted on said bearing with said at least one relief being positioned axially to sit abreast of, and to overlie, top dead center of at least one of said bearing races.
19. A combination of a bearing adapter, a sideframe having at least a first pedestal seat, and a resilient pad for use with the bearing adapter; at least one of (a) said bearing adapter and (b) said sideframe being the member according to claim 1 , wherein the bearing adapter and the first pedestal seat have respective mutually engageable rolling contact surfaces, said resilient pad has a first portion for engaging a first end of the bearing adapter, a second portion for engaging a second end of the bearing adapter, and a medial portion between said first and second end portions, said medial portion being formed to accommodate mating engagement of the mutually engageable rolling contact surfaces.