Figure 1 Industrial hydraulic cylinder of the hexapod with a flanged Ratio-Clamp®
Figure 2 Airplane A380 of Airbus
Figure 3 Airplane wing test stand for simulating the airstream with low friction hydraulic cylinder
Figure 1 Slat station with 14 industrial hydraulic cylinders by Hänchen
Figure 2 Monitoring and controlling of the wing tests
Figure 3 Left: Dipl.-Ing. Michael Johst, Head of High Lift Rig Operations & Maintenance at Airbus Germany in Bremen
Cross section of a Ratio-Clamp® clamping unit with a Servocop® sealing system
Clamping unit Ratio-Clamp®
To fix the hexapods securely even without applied pressure for an unlimited period of time, all hydraulic cylinders feature a flanged clamping unit Ratio-Clamp® on the flaps. This patented clamping is designed for a holding load of between 140 and 300 kN, depending on the cylinder. The force is stored in screw plate springs and fixes the rod via a conic clamping element through frictional contact in case of pressure loss. The applied spring sets and the length of the cone exactly define clamping force and trigger pressure here. This clamping procedure can be triggered by direct cut-off, reduction of pressure or a power failure as well as system damages. This clamping force is then preserved for any amount of time without energy supply until the releasing pressure is applied again and the piston rod thus released. In case of applied pressure, the rod can be turned in both directions with low friction. The use of Ratio-Clamp® also provides the typical advantages of a hydraulic system: high power density and precise reaction due to the minimal compressibility of the fluid. This practically rules out damage on the expensive Airbus test stands, for example in case of a failure of the hydraulic supply.
Hänchen is a must in Bremen
"We like to work with Hänchen cylinders and clamps, because they have proven themselves well and maintain the promised quality," summarised the leading test engineer Johst. "We have gathered this experience since our first high lift tests in 1980. Even though we work in many sectors with several partners: Hänchen products are a standard in our company."
Jörg Beyer, mediaword
© Hänchen 2013