Three-piece motion control truck system
View Patent ↗An improved three-piece truck system for railroad cars provides long travel side bearings for improved stability, a “wide” friction shoe design or equivalent to improve sideframe and bolster squareness, a resilient pedestal pad for improved curving performance and enhanced wear resistance, and a suspension system tuned and optimized for rail cars to have a minimum reserve capacity of less than 1.5 to improve motion control and ride quality, increase resistance to suspension bottoming, and increase hunting threshold speed. Such a motion control truck system is able to meet recent, more stringent American Association of Railroads standards, such as M-976, for railcars having a 286,000 lb. gross rail load rating.
1. A railway car truck with a railway car thereon having a gross weight on rail rating of at least 286,000 pounds, comprising:
two sideframes, each sideframe having a pedestal formed on opposite ends thereof and substantially upright columns defining a sideframe opening intermediate the pedestals, friction surfaces being provided on the upright columns, each pedestal having a pedestal opening sized to receive a bearing adapter;
a bolster transversely situated relative to the sideframes and supported within the sideframe openings, the bolster including side bearing pads on an upper surface of the bolster between the sideframes;
a truck suspension consisting of a spring group provided in each sideframe opening that supports respective ends of the bolster, the spring group having a minimum reserve capacity of less than 1.5;
and at least one of the following:
long travel side bearings provided on each side bearing pad, the long travel side bearings including a base, a cap, and at least one resilient urging element having a travel of at least ⅝″ before the urging element is fully compressed or the base and cap bottom out;
high squareness friction shoes disposed between the bolster and the sideframe openings, each friction shoe including a substantially vertical wall engageable with the friction surface on the upright columns and a friction face; and
an elastomeric pad disposed on a roof of the pedestal opening so as to be disposed between the pedestal and the bearing adapter in use.
2. The railway car truck according to claim 1 , wherein the friction shoes have an effective friction face of at least about 8 inches.
3. The railway car truck according to claim 2 , wherein the friction shoes are of a split wedge design having two separate shoe members and an insert member, the two separate shoe members being spread outward during bolster travel to achieve the effective friction face.
4. The railway car truck according to claim 2 , wherein the friction shoes are a compound slope angle shoe.
5. The railway car truck according to claim 2 , wherein the friction shoes have a fixed bias.
6. The railway car truck according to claim 2 , wherein the friction shoes have a variable bias.
7. The railway car truck according to claim 1 , wherein the truck includes at least long travel side bearings, a truck suspension with a reserve capacity of less than 1.5, and high squareness friction shoes having an effective friction face of at least about 8 inches.
8. The railway car truck according to claim 1 , wherein the truck includes at least long travel side bearings, a truck suspension with a reserve capacity of less than 1.5, and an elastomeric pad disposed on a roof of the pedestal opening so as to be disposed between the pedestal and the bearing adapter in use.
9. The railway car truck according to claim 8 , wherein the elastomeric pad is formed from natural rubber or plastic.
10. The railway car truck according to claim 1 , wherein the long travel side bearings have a combined load rating of between about 4,000 to 6,000 lb/in.
11. The railway car truck according to claim 10 , wherein the long travel side bearings have a longitudinal spatial gap between the base and the cap of between about 0.006–0.046 inches.
12. The railway car truck according to claim 1 , wherein the long travel side bearings have a resilient urging member in the form of at least one coil spring.
13. A railway car truck for use with a railway car having a gross weight on rail rating of at least 286,000 pounds, comprising:
two sideframes, each sideframe having a pedestal formed on opposite ends thereof and substantially upright columns defining a sideframe opening intermediate the pedestals, friction surfaces being provided on the upright columns, each pedestal having a pedestal opening sized to receive a bearing adapter;
a bolster transversely situated relative to the sideframes and supported within the sideframe openings, the bolster including side bearing pads on an upper surface of the bolster between the sideframes;
long travel side bearings provided on each side bearing pad, the long travel side bearings including a base, a cap, and at least one resilient urging element having a travel of at least ⅝″ before the urging element is fully compressed or the base and cap bottom out;
a truck suspension consisting of a spring group provided in each sideframe opening that supports respective ends of the bolster, the spring group having a minimum reserve capacity of less than 1.5;
high squareness friction shoes disposed between the bolster and the sideframe openings, each friction shoe including a substantially vertical wall engageable with the friction surface on the upright columns and a friction face, wherein the friction shoes maintain substantial squareness of the bolster with the sideframes; and
an elastomeric pad disposed on a roof of the pedestal opening so as to be disposed between the pedestal and the bearing adapter in use.
14. The railway car truck according to claim 13 , wherein the friction shoes have an effective friction face of at least about 8 inches.
15. The railway car truck according to claim 14 , wherein the friction shoes are of a split wedge design having two separate shoe members and an insert member, the two separate members being spread outward during bolster travel to achieve the effective friction face.
16. The railway car truck according to claim 13 , wherein the friction shoes are a compound slope angle shoe.
17. The railway car truck according to claim 13 , wherein the long travel side bearings have a resilient urging member in the form of at least one coil spring.
18. The railway car truck according to claim 13 , wherein the elastomeric pad is formed from natural rubber or plastic.
19. The railway car truck according to claim 13 , wherein the long travel side bearings have a combined load rating of between about 4,000 to 6,000 lb/in.
20. The railway car truck according to claim 19 , wherein the long travel side bearings have a longitudinal spatial gap between the base and the cap of between about 0.006–0.046 inches.
21. The railway car truck according to claim 13 , wherein the friction shoes have a fixed bias.
22. The railway car truck according to claim 13 , wherein the friction shoes have a variable bias.