Spring system of a rail vehicle

Patent metadata

Field	Value
Publication number	US-9878727-B2
Application number	US-201514971350-A
Country	US
Kind code	B2
Filing date	Dec 16, 2015
Priority date	Dec 17, 2014
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

Abstract

A rail vehicle spring system has a spring strut, arranged between a bogie and carriage body of the rail vehicle, and includes a cylinder and a piston in the cylinder. Piston spaces are defined below and above the piston head. The piston or the cylinder is connectable with the bogie, while the other component is connectable with the carriage body. A spring cushions the body relative to the bogie, and a hydraulic system is connected with at least one of the piston spaces to charge the space with hydraulic medium. The spring surrounds the cylinder and is contracted by the piston when an excess pressure exists in the lower piston space with respect to the upper piston space, and an entraining element is adjoined by the spring. Only when an excess pressure exists in the lower piston space does the piston rod exerts a force on the entraining element.

First claim

The invention claimed is:

1. A spring system of a rail vehicle with a spring strut for arrangement between a bogie and a carriage body of the rail vehicle, the spring strut comprising:
a cylinder,
a piston shiftably accommodated in the cylinder and including a piston head, defining lower and upper piston spaces below and above the piston head, and a piston rod, one of the piston and the cylinder being directly or indirectly connectable with the bogie and the other of the piston and the cylinder being directly or indirectly connectable with the carriage body,
a spring arranged to cushion the carriage body with respect to the bogie, and
an entraining element that adjoins the spring, wherein
the spring system includes a hydraulic system connected with at least one of the piston spaces such that the at least one of the piston spaces can be charged with hydraulic medium,
the piston spaces are arranged such that the spring is contracted by the piston when an excess pressure exists in the lower piston space with respect to the upper piston space,
the spring surrounds the cylinder,
the piston rod is arranged such that the piston rod only exerts a force on the entraining element when an excess pressure exists in the lower piston space with respect to the upper piston space, and
the piston rod, when no excess pressure exists in the lower piston space with respect to the upper piston space, has a clearance with respect to the entraining element in at least one of a transverse direction relative to the piston and a direction of movement of the piston.

2. The spring system according to claim 1 , wherein the piston and the cylinder form a unit having a first end and a second end, and only one of the first and second ends directly or indirectly is firmly connected with the spring.

3. The spring system according to claim 1 , wherein at least one portion of the piston rod is designed flexible or articulated.

4. The spring system according to claim 3 , wherein the at least one portion of the piston rod is formed tapered with respect to adjacent regions or is formed by a movable coupling rod, chain, or wire rope.

5. The spring system according to claim 2 , wherein the unit is a first unit, and further comprising a further piston-cylinder unit arranged in series with the first unit for wheel wear compensation.

6. The spring system according to claim 1 , wherein the lower piston space, when an excess pressure exists therein with respect to the upper piston space, is in a condition charged with hydraulic medium, and when no excess pressure exists in the lower piston space with respect to the upper piston space, is in a condition not charged with hydraulic medium.

7. The spring system according to claim 6 , wherein only exactly one hydraulic line extends from the hydraulic system to the lower piston space.

8. The spring system according to claim 6 , wherein the hydraulic system includes two 2/2-way valves or one 3/2-way valve for the lower piston space.

9. The spring system according to claim 6 , wherein the hydraulic system is formed such that relief for the lower piston space is designed redundant.

10. The spring system according to claim 6 , wherein the hydraulic system includes a tank, and, between the tank and the lower piston space, and between a pump and the lower piston space, normally open valves exclusively are provided to relieve the lower piston space to permit redundant relief without provision of additional valves.

11. The spring system according to claim 6 , wherein the hydraulic system includes one actuation strand for each piston space, bogie axle, or carriage body.

12. The spring system according to claim 1 , wherein, from the hydraulic system, at least one hydraulic line each extends to the lower piston space and to the upper piston space, and the at least one hydraulic line extending to the upper piston space branches off from the at least one hydraulic line extending to the lower piston space.

13. The spring system according to claim 12 , wherein, in the at least one hydraulic line extending to the upper piston space, a normally open 2/2-way valve is arranged.

14. The spring system according to claim 12 , wherein, from the hydraulic line extending to the upper piston space, a relief line branches off on a piston side of the 2/2-way valve.

15. The spring system according to claim 14 , further comprising a pressure limiting valve arranged in the relief line that provides for a discharge of hydraulic fluid from the upper piston space when an excess pressure is reached.

16. The spring system according to claim 14 , wherein, in the relief line, a normally open 2/2-way valve is arranged, and/or in the hydraulic line, of the upper piston space, a normally closed 2/2-way valve is arranged on a piston space side of a branching point.

17. The spring system according to claim 1 , further comprising a height sensor arranged to emit a signal characteristic for the length of the spring strut.

18. The spring system according to claim 17 , further comprising a control or regulating unit provided for height adjustment and connected with the height sensor and the hydraulic system such that a certain value of a height of the spring strut is adjustable.

19. A rail vehicle, with the spring system according to claim 1 .

Assignees

• Liebherr Aerospace Lindenberg GmbH

Inventors

• Gaile Anton

Classifications

• B60G17/0272

  the mechanical spring being a coil spring · CPC title

• B61F5/06

  incorporating metal springs · CPC title

• B60G17/033

  characterised by regulating means acting on more than one spring · CPC title

• B61F5/10 Primary

  incorporating fluid springs · CPC title

• B60G11/16

  characterised by means specially adapted for attaching the spring to axle or sprung part of the vehicle · CPC title