Sealed dampers operate according a two-direction oil flow through the piston. The construction of the damper is such that the damping forces during the extension and compression stroke are symmetrical.
During the extension stroke the damping is performed by a valve stack below the piston, while during the compression stroke the valve stack on top of the piston creates the desired damping forces.
The mechnical dampers are provided with a blow-off at higher damper speeds. This blow-off limits the maximum forces created by severe track conditions.
This feature results in increased passenger comfort and protects both the damper as well as the vehicle brackets from excessive forces.
Orifice damping at
low damper speeds |
Main valve damping at
medium damper speeds |
Blow-off at high
damper speeds |
These dampers are provided with the following specific railway features:
- Robust construction resulting in a long service life.
- Symmetrical force in extension and compression.
- Linear force rate up to a freely defined blow-off point.
- Maintainable or sealed construction at customer’s request.
- The special synthetic rings around the piston and the guide, result in the absence of any metal to metal contact.
- High quality silent blocks.
- Noise-free valve systems.
Characteristics
Due to the unique valve system of the Sealed dampers, nearly every required characteristic can be provided within an unmatched narrow tolerance band.
The following maximum damping rates and damping forces apply for the various damper types within Sealed dampers:
| Type 90 |
|
| Max. damping force |
10 kN |
| Max. damping rate |
35 kNs/m |
| Dust cover / reservoir tube |
Ø 80 mm / Ø 70 mm |
| |
|
| Type 97 |
|
| Max. damping force |
15 kN |
| Max. damping rate |
100 kNs/m |
| Dust cover / reservoir tube |
Ø 80 mm / Ø 70 mm |