Rail road car truck with bearing adapter and method

• US 6,874,426 B2
• Filed: 02/03/2003
• Issued: 04/05/2005
• Est. Priority Date: 08/01/2002
• Status: Expired due to Term

• Current Assignee: National Steel Car Limited
• Original Assignee: National Steel Car Limited
• Inventors: Forbes, James W.
• Primary Examiner(s): Le, Mark T.
• Application Number:
  US10/357,318
• Publication Number:
  US 20040020403A1
• Time in Patent Office: 792 Days
• Field of Search: 105/157.1, 105/171, 105/174, 105/179, 105/182.1, 105/187, 105/190.1, 105/198, 105/206.1, 105/218.1, 105/218.2, 105/219, 105/220, 105/223
• US Class Current: 105/223
• CPC Class Codes: B61D 3/18 for vehicles vehicles adapted to carry other vehicles, in general, B60P3/06
• CPC Class Codes: B61F 5/06 incorporating metal springs
• CPC Class Codes: B61F 5/122 with friction surfaces
• CPC Class Codes: B61F 5/30 Axle-boxes mounted for movement under spring control in vehicle or bogie underframes B61F5/36 takes precedence over B61F5/305 - B61F5/34
• CPC Class Codes: Y10T 29/4973 Replacing of defective part

Abstract

A swing motion rail road freight car truck is provided that has a truck bolster and a pair of side frames, the truck bolster being mounted transversely relative to the side frames. The side frames have spring seats for the groups of springs. The springs seats may be rigidly mounted in the side frames. Friction dampers are provided in inboard and outboard pairs. The biasing force on the dampers urges then to that act between the bolster ands and sideframes to resist parallelogram deflection of the truck. The bearing adapters and sideframe pedestal seats interact on a rolling linear contact interface that has a relatively small radius of curvature.

Claims

1. A rail road car truck comprising:

a pair of first and second side frames and a truck bolster resiliently mounted transversely relative thereto;

wheelsets, each wheelset having an axle having two wheels mounted thereto, and each axle being mounted to said side frames;

each of said side frames having pedestal seats for receiving mating bearing adapters;

a bearing adapter mounted to each end of each axle, each bearing adapter being matingly engaged in one of said pedestal seats;

said pedestal seats having a bearing surface for mating with said bearing adapter;

said mating bearing surface being chosen from the set of bearing surfaces consisting of (a) a planar surface; and

(b) an arcuate surface having a radius of curvature greater than 50 inches;

said bearing adapter having a crown upon which said bearing surface of said pedestal seat is engaged to permit lateral rocking motion of said sideframe;

said crown having a local radius of curvature of less than 30 inches.

2. The rail road car truck of claim 1 wherein said radius of curvature is constant over an arc extending at least 2 degrees to either side of a central resting position.

3. The rail road car truck of claim 1 wherein said truck bolster has lateral travel relative to said side frames of at least 1 inch to either side of a central resting position.

4. The rail road car truck of claim 3 wherein said lateral travel of said truck bolster relative to said side frames is limited by abutment means mounted thereto.

5. The rail road car truck of claim 4 wherein said abutment means includes at least one gib mounted to one of (a) said truck bolster and (b) said side frames, and a mating abutment mounted to the other of(a) said side frames, and (b) said truck bolster.

6. The bearing adapter of claim 1 wherein said radius of curvature is less than 10 inches.

7. A bearing adapter for use in a three-piece rail road car truck, the bearing adapter being mountable to a bearing of an end of an axle of a rail road car wheelset, wherein the bearing adapter has a crown for engaging a pedestal seat of a side frame of the rail road car truck, said crown permitting transverse rocking of the side frame mounted thereon, said crown having a first region rockingly engageable with a contact surface of the pedestal seat, said first region including a crest having a local radius of curvature of less than 30inches, and said crown having a second region adjoining said first region, said second region being configured to rockingly engage said contact surface of the pedestal seat, and said second region of said crown has a different radius of curvature than said crest.

8. The bearing adapter of claim 7 wherein said second region has a local radius of curvature greater than said crest region.

9. The bearing adapter of claim 7 wherein said radius of curvature of said crown varies from a first radius of curvature at said crest to a greater radius of curvature away from said crest.

10. The bearing adapter of claim 7 wherein said radius of curvature is constant over a range of motion of at least 2 degrees of arc to either side of a central position.

11. The combination of a bearing adapter for a rail road freight car truck, and a mating pedestal seat for a sideframe of a rail road freight car truck, said bearing adapter having a crown, said pedestal seat having a mating bearing surface for rocking engagement with said crown to permit lateral rocking of the sideframe, said crown having a radius of curvature, said mating bearing surface being chosen from the set of bearing surfaces consisting of (a) a planar surface;

and (b) an arcuate surface having a radius of curvature greater than 50 inches; and

said radius of curvature of said crown being less than 30 inches.

12. The combination of claim 11 wherein said radius of curvature of said crown is constant over an arc extending at least 2 degrees to either side of a central resting position.

13. The combination of claim 11 wherein said radius of curvature of said crown is less than 10 inches.

14. The combination of claim 11 wherein said crown has a first region at said crest, and a second region adjacent thereto, said second region having a local radius of curvature greater than said crest region.

15. The combination of claim 14 wherein said radius of curvature of said crown varies from a first radius of curvature at said crest to a greater radius of curvature away from said crest.

16. A process of retro-fitting a two axle, four wheel, three piece rail road car truck having a pair of side frames, a truck bolster resiliently mounted transversely to said side frames, said axles having bearings mounted thereto and (first bearing adapters mounted to said bearings, said side frames having bearing pedestal mounts, said bearing adapters being rockingly engaged with said bearing pedestal mounts to permit lateral swinging of said side frames, each said bearing adapter having a crowned surface rockingly engaged to a mating bearing surface of said bearing pedestal mount, said crowned surface having a radius of curvature of greater than 50 inches, said process comprising the steps of (a) extracting said bearing adapters from said truck;

(b) replacing said first bearing adapters with second bearing adapters having a crowned surface having a smaller radius of curvature than before, and (c) installing an arrangement of dampers between the bolster and each sideframe, each said arrangement of dampers including four dampers and having four corners, and said second bearing adapters having a radius of curvature of less than 30 inches.

17. A three piece rail road car truck, said truck comprising a pair of spaced apart sideframes and a truck bolster extending therebetween, said truck bolster having ends resiliently supported by said side frames, said side frames being mounted on wheel sets, each said wheelset having an axle and two wheels mounted thereto, each said wheelset having bearings and bearing adapters mounted thereto, said bearing adapters having crowns, said sideframes having pedestal seats for mating engagement with said crowns of said curvature of less than 30 inches, each of said ends of said truck bolster having an arrangement of dampers, each said arrangement of dampers including four dampers and having four corners, and each said arrangement of dampers being mounted to act between one of said ends of said bolster and one of said sideframes.