Side bearing for railway car truck

Abstract

An improved leaf spring side bearing assembly for railway freight cars is provided that achieves improved tracking and curving by the limitation of rock of the railway freight car. The side bearing comprises a base with two raised end sections. A leaf spring assembly is provided on the base that extends to the underside and support channel of the freight car. A top wear plate and a bottom travel stop are also included with the leaf spring side bearing assembly.

Claims

1. A side bearing assembly comprising: a base structure having two ends, four shackles, each shackle connected to one of the base structure ends, a leaf spring assembly having two ends, two leaf spring end clamps, each leaf spring end clamp connected to each end of the leaf spring assembly, each leaf spring end clamp also connected to two of the shackles, a top clamp joining a top portion of the leaf spring assembly, and a bottom stop connected to a bottom of the top clamp.

2. The side bearing assembly of claim 1 further comprising a wear plate positioned between the top portion of the leaf spring assembly and the clamp.

3. The side bearing assembly of claim 1 further comprising a first pin joining the shackle to the base structure end in a manner to allow rotation between the shackle and the base structure end.

4. The side bearing assembly of claim 1 further comprising a second pin joining the shackle to the leaf spring end clamp in a manner to allow rotation between the shackle and the leaf spring end clamp.

5. The side bearing assembly of claim 1 wherein the maximum travel of the leaf spring assembly downward from an unloaded position is less than 0.625 inch.

6. The side bearing assembly of claim 1 wherein the leaf spring assembly is comprised of a glass fiber reinforced polymer leaf spring.

7. A side bearing assembly comprising: a base structure having two ends, a plurality of shackles, each shackle connected to one of the base structure ends, a leaf spring having two ends and a top portion, two leaf spring end clamps, with each leaf spring end clamp connected to one end of the leaf spring, each leaf spring end clamp also connected to two of the shackles, a top clamp joining the top portion of the leaf spring, and a bottom stop connected to a bottom of the top clamp.

8. The side bearing assembly of claim 7 further comprising a wear plate positioned between the top portion of the leaf spring and the top clamp.

9. The side bearing assembly of claim 7 further comprising a first pin joining the shackle to the base structure end in a manner to allow rotation between the shackle and the base structure end.

10. The side bearing assembly of claim 7 further comprising a second pin joining the shackle to the leaf spring end clamp in a manner to allow rotation between the shackle and the leaf spring end clamp.

11. The side bearing assembly of claim 7 wherein the maximum travel of the top portion of the leaf spring downward from an unloaded position is less than 0.625 inch.

12. The side bearing assembly of claim 7 wherein the leaf spring is comprised of a glass fiber reinforced polymer leaf spring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings,

(2) FIG. 1 is a perspective view of a typical railway freight car truck;

(3) FIG. 2 is a top view of a leaf spring assembly side bearing in accordance with an embodiment of the present invention;

(4) FIG. 3 is an end view of a leaf spring assembly side bearing in accordance with an embodiment of the present invention;

(5) FIG. 4 is a perspective view of a leaf spring assembly side bearing in accordance with an embodiment of the present invention;

(6) FIG. 5 is a side view of a leaf spring assembly side bearing in accordance with an embodiment of the present invention;

(7) FIG. 6 is a perspective view of a typical railway freight car truck in accordance with and embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

(8) Referring now to FIGS. 2-6, a first embodiment of the leaf spring assembly side bearing according to the present invention is shown at 10. Side bearing assembly 10 includes a base structure 1, which is comprised of a bottom portion 22 and end structures 24 extending vertically upward from each end of bottom portion 22. Base structure 1 is usually cast steel or cast iron unitary structure, but can be a fabricated or machined steel plate as well, with end structures 24 being unitary or welded or otherwise affixed to the ends of bottom portion 22. The shape of bottom portion 22 can be somewhat rectangular, or somewhat oval or diamond shaped as the use dictates.

(9) Bottom portion 22 of base 1 includes openings (not shown) that allow the ready attachment of base 1 to side bearing pad 60 of bolster 38 by bolts or similar devices.

(10) Shackles 2 are used to connect base end structures 24 to leaf spring end clamps 4 by the use of pins 3. Leaf spring end clamps 4 are connected to the ends of leaf springs 5 by similar pins 3A. Shackles 2 can be cast, machined or stamped steel, and when combined with pins 3 and 3A, allow leaf springs 5 to compress and flex as the load force from the freight car is applied to the leaf spring assembly side bearing 10.

(11) Leaf springs 5 can be comprised of a mono-leaf spring or of multiple laminated leaf springs. Leaf spring 5 elements may be made of a glass fiber reinforced polymer, or in certain applications, spring steel.

(12) Clamps 7 are used to hold the leaf spring together at the top of the leaf springs. Clamps 7 are usually comprised of steel bar stock, which is held by bolts 7A or similar devices. Top wear plate 6 is positioned between clamp 7 and the top of leaf springs 5 to provide improved wear resistance between the bottom of the freight car support channel and leaf spring 5. Top wear plate 6 is usually made of a steel with a 10-15% manganese content.

(13) Bottom stop 8 is placed at the bottom of clamp 7 to restrict the down travel of leaf springs 5. Bottom stop 8 is usually made of cast or machined steel, and is affixed to clamp 7 by bolts 7A. Bottom stop 8 is designed to limit the down travel of leaf springs 5 when measured at clamp 7 to no more than 0.625 inch (1.58 cm). Such limitation in the down travel of leaf spring 5 would limit the rock of the railway freight car.