Metal bellows
Metal bellows are ring-shaped cylinder of metal that have a wavy changing diameter.
They are used as Wellrohrkompensator in pipes and fittings, metal bellows as between waves, a separating diaphragm in hydraulic accumulators and for other purposes.
The bladders are formed from thin-walled tubes, which are continuously produced by longitudinal seam welding of thin strips ( 0.1 to 0.8 mm). The subsequent transformation to a corrugated tube can isostatically, hydraulically or mechanically carried by rollers. All cold malleable and weldable materials are processed.
The bellows are used to compensate for movements in the axial or lateral direction as well as to compensate for angular deviations of the geometric axes of the flanges. Torques are transmitted rigid and free of play.
Multi-ply bellows
To increase and stability while maintaining the flexibility of metal bellows are manufactured in multiple layers. It can be used as a wall of the bladder several thin metal layers. The combination of different materials brings other advantages. One of the layers is damaged over time, the remaining gas-tight to prevent leakage of the medium layers.
For the transport of aggressive fluids, the inner layer, the outer layers can be made of a corrosion -resistant material, on the other hand of mechanical cheaper materials.
Applications
Flexible pipe joint
At vehicle and aircraft engines, including the exhaust system of motor vehicles, so-called decoupling elements are used on the basis of metal bellows for decoupling unit oscillations ( see also Wellrohrkompensator ).
Miniaturbälge used in piezo injection systems and valve actuators as a sealing element. For the piezo - injection (200 bar operating pressure) completed each bellows over a billion load changes throughout the operating life of the vehicle.
Since corrugated tubes withstand pressure from the outside, they are also found in vacuum systems.
The differential pressure between the inside and outside leads to an axial force which has to be taken into account or can also be used constructively.
Pump and cylinder
Gas-tight metal bellows come as a pressure accumulator for braking energy in hybrid vehicles for use.
In medical Miniaturbälge be used in insulin pumps implants.
Heat exchanger
Corrugated tubes of metal are used because of their large specific surface area in heat exchangers.
Torque transmission
In the machine tool and precision engineering Metal Bellows are used as permanent fixed coupling elements for play-free direct transmission of starting and operating torque and simultaneous compensation of axial offset.