KARSUS
for Railway

The K142 and K143 railway shock absorber

Our K142 and K143 rail shock absorber type families are designed for general purpose and normal speed rail vehicles. After manufacturing tens of thousands of shock absorbers, we can rightly say that it is one of our most popular products.

Construction of K142 and K143 railway shock absorber series follow the requirements imposed by the modern shock absorbers:

  • Metal-free contact between friction elements.
  • Valve-controlled damping.
  • High-pressure seals for precise adjusting.
  • Bleeder system is used.
  • Foaming-free system is used.
  • Recyclable and ready-to-assembly implementation.
  • Hardened, chrome plated piston rod.
  • Extra high protection against dust (with K143 series).

The above mentioned characteristic features result in long-life usage. Their renewability makes them more valuable. With continuous maintenance lifespan of these shock absorbers can reach 25-30 years. It is not a negligible fact that the cost of recycling is much lower than that of a new shock absorber.

Principle of operation

The operating principle of the Kárászy K142 and K143 railway shock absorber type family is based on the operating principle of traditional twin-tube shock absorbers. The damping force is generated by the damping valve built into the piston when pulled and by the foot valve when pushed. Thanks to the special geometry, the shock absorbers have symmetrical characteristics, but deviations from this are also possible.

The valves built into the shock absorbers are adjusted in a unique way in the world, on the valve adjusting device designed by our engineers, so we can be sure that the characteristics of the shock absorber will be as required after assembly.

Technical specifications:

  • Max. damping force at 0,1m/s: 6kN
  • Diameter of dust protector tube/shock absorber casing: Ø90mm / Ø80mm

K144 railway shock absorber

K144 railway shock absorbers

Our K144 railway shock absorber type family has been developed with a robust design to provide higher damping forces. In many places, due to the design of the bogie or the weight of the vehicle, it is necessary to use shock absorbers that provide a higher damping force than the average (approx. 5000-6000N at a piston speed of 0.1 m / s). Series K144 is designed for high load with robust size. Series K144 doubles the maximum damping force of standard shock absorbers and this way it provides proper damping for massive vehicles.

Specifications:

  • Robust design.
  • Mounting elements and silent blocks which fit high damping forces.
  • Hardened, chrome plated piston rod.
  • Metal-free contact between friction elements.
  • Valve-controlled damping.
  • Max. damping force 12 000 N at 0,1 m/s piston velocity.
  • Recyclable design.

K144 shock absorbers are designed for long-life usage due to their design (material quality, up-to-date construction, appropriate surface protection).

Due to the increased damping force, our engineers pay special attention to the design of the mounting elements. Each load-bearing element of the welded shock absorber housing is the result of careful design work. The welding workflow is also carried out under engineering supervision, with strict adherence to the regulations, thus ensuring the perfect end result.

Principle of operation

The operating principle of the Kárászy K144 railway shock absorber type family is based on the operating principle of traditional twin-tube shock absorbers. The damping force is created by pulling on the damping valve built into the piston, and when pushing, by the cooperation of the damping valve built into the foot valve housing and the piston. Thanks to the special valve design, the shock absorbers have symmetrical characteristics, but deviations from this are also possible.

Technical specifications:

  • Max. damping force at 0,1 m/s: 12kN
  • Diameter of dust protector tube/shock absorber casing: Ø110 mm / Ø100 mm

The K145 railway shock absorbers

Kárászy K145 railway shock absorber series is a hybrid version of series K142 and K143. Due to bogie construction it might happen that there is not enough space for the installation of an average size and stroke-length shock absorber. That is why our engineers designed the compact version of the most popular series which minimum installation height allows construction of quite short shock absorbers:

  • Space-saving construction.
  • All positive features of K142 and K143 can be found in system K145.
  • Hardened, chrome-plated piston.
  • Bleeder system is used.
  • Foaming-free system is used.
  • The most modern seal system is applied.
  • Recyclable and ready-to-assembly product.

Lifespan of Series K145 is the same as the ones of K142/143 because they inherited all the specifications which increase their lifetime so the greatest advantage of this system is the previously mentioned compact design.

Principle of operation

The operating principle of the Kárászy K145 railway shock absorber type family is based on the operating principle of traditional twin-tube shock absorbers. The damping force is generated by the damping valve built into the piston when pulled and by the foot valve when pushed. Thanks to the special geometry, the shock absorbers have symmetrical characteristics, but deviations from this are also possible.

The valves built into the shock absorbers are adjusted in a unique way in the world, on the valve adjusting device designed by our engineers, so we can be sure that the characteristics of the shock absorber will be as required after assembly.

Technical specifications:

  • Max. damping force at 0,1m/s: 6kN
  • Diameter of dust protector tube/shock absorber casing: Ø90mm / Ø80mm

The K146 railway shock absorbers

The most typical needs of railway vehicle operators these days is to develop high speed railway lines and to purchase high speed vehicles associated with them. Thus, demand on behalf of railway vehicle manufacturers has grown for rail car shock absorbers which are able to resist the extreme stresses accompanying high speed travel reliably on the long term and to provide appropriate comfort to passengers. Our company developed the product lines K146 and K147 for rail car shock absorbers to meet these requirements.

At high speed the effect of so-called unstable run may be encountered when the bogie truck turns away freely in horizontal directions under the car body (wobbling). In order to prevent the low amplitude swaying movements the low mass bogie is stabilised with a shock absorber structure against the large mass body car, which is considered to be a fixed point in this respect. This is why these devices are called rail car sway control shock absorbers. Two key requirements for the characteristic curve of the shock absorbers is to be similar to the characteristic curve of a friction shock absorber but to avoid all disadvantages of the former. Another fundamental requirement is to allow the installation of the shock absorbers in horizontal position, for which our company developed a simple but efficient method. 

Thanks to the valve design of the K146 system these products can be used not only to serve the purpose of sway control shock absorbers but also as shock absorbers between car bodies (anti-roll dampers) or in any other places of installation for vehicles with higher damping force requirements.

Key features:

  • Robust built to absorb extensive damping forces
  • Fastening components providing large angular displacement 
  • Damping force adjustable in a wide range
  • Damping force adjustable irrespective of the direction of stress
  • Custom built valve design developed by Kárászy Kft. 
  • Rail car sway control shock absorbing design to be applied in high speed (>250km/h) vehicles
  • Mountable, recyclable design
  • No metallic contact between friction elements

Engineers at our company have considered the long term useful lifetime up to 25 years as a fundamental design consideration when designing the K146 product line. In order to achieve this wearing parts and components were applied so that they did not contact with metallic contacts and if they are replaced periodically, you can say that the shock absorber has gained an unlimited useful lifetime.

Engineering details:

Maximum damping force at a speed of 0.1 m/s: 20 kN

Diameter of dust protector tube/shock absorber casing: Ø 110 mm / Ø 100 mm

The K147 railway shock absorbers

The most typical needs of railway vehicle operators these days is to develop high speed railway lines and to purchase high speed vehicles associated with them. Thus, demand on behalf of railway vehicle manufacturers has grown for rail car shock absorbers which are able to resist the extreme stresses accompanying high speed travel reliably on the long term and to provide appropriate comfort to passengers. Our company developed the product lines K146 and K147 for rail car shock absorbers to meet these requirements.

The development of the K147 system took place in parallel with that of the K146 line. The design aim was to create a modern valve controlled architecture which is suitable to produce shock absorbers with sway control properties (K146) and to attenuate the oscillation of primary and secondary suspension system elements (K147). Damping force of the product line K147 can be adjusted in a wide range and hence, almost any needs can be met by it. 

Key features:

  • Damping force adjustable in a wide range
  • Damping force adjustable irrespective of the direction of stress
  • Applicable in high speed (>250km/h) vehicles
  • Mountable, recyclable design
  • No metallic contact between friction elements
  • Increased amount of oil for efficiency
  • Double anti-dust protection
  • Custom built valve design developed by Kárászy Kft.

Due to the increased oil volume the warming up of the shock absorber is slowed down, therefore the useful lifetime of the oil will be extended which means operational safety on the long run. Since safe running stability of railway vehicles travelling at a high speed can only be ensured with the use of appropriate shock absorbers, our company developed the product lines K146 and K147.

Engineering details:

Maximum damping force at a speed of 0.1 m/s: 20 kN

Diameter of dust protector tube/shock absorber casing: Ø 110 mm / Ø 100 mm