The double girder travelling crane ZL:
─ The crane is manufactured as a ZLV overhead travelling crane from a rolled I-beam.
─ The crane is manufactured as a ZLK overhead travelling crane from a welded box girder. All six outer welds are welded at the same time, torsion-free.
─ The overhead travelling crane is available with 4-wheel crane travel drive (all-wheel) (option). This is required whenever the crane travel drive needs to be particularly sturdy (e.g. for operation outdoors with a headwind, or travelling through curtains).
─ As standard, the crane has an ABURemote radio remote control. Alternatively or in addition, the crane can have a mobile control. This ensures the position of the pendant control is independent of the trolley position.
─ The crane is controlled using the ABURemote radio remote control. Alternatively or in addition as an “Emergency control”, the crane can be controlled using the “ABUCommander” pendant control. Both the radio remote control and pendant control have two-stage buttons with which the crane can be controlled at low and high speed for travel or lifting.
─ The trolley and the optional mobile control come as standard with an energy chain connected to the rest of the crane’s electrics. As a variation, the trolley and the mobile control can be connected to the rest of the crane’s electrics with a festoon cable system.
The double girder travelling crane with two trolleys:
─ The trolleys are labelled “Trolley I” and “Trolley II” on the wire rope hoist and on the radio remote control or on the pendant control.
─ The end carriages are fully-automatic, welded box girders.
─ The end carriages are connected to the main girders using high-tensile bolts.
─ The end carriages (according to the respective width of the crane track) have wheels with wheel flanges, which enable even running on the crane track and prevent the overhead travelling crane from derailing.
─ The end carriages can be fitted with an additional derailing protection device on all four wheels (option).
─ The end carriages can be fitted with guide rollers (option) to equalise the tolerances of the crane track. For this, one of the two end carriages is fitted with two horizontal guide rollers on both wheels. These run left and right close to the crane track. The crane is thus closely guided on one side. The other side has very wide wheels to compensate for the tolerance.
The other end carriages (without guide rollers) can also be fitted with a derailing protection device on both wheels (option).
The end carriages of the sizes 280, 350 and 420:
─ The end carriages of the sizes 280, 350 and 420 have a clamping piece on the powered wheel.
─ The end carriages of the sizes 280, 350 and 420 have a special rigidity aid on the inside, called a clamp brace, which transfers the stress from the main girder to the end carriages.
The size 500 end carriages:
─ The end carriages of size 500 are welded box girders with an optimised contour for high wheel loads.
─ The size 500 end carriages are outstandingly robust and rigid.
The crane travel drives:
─ The drives are designed as pole-variable rotary current motors with electromagnetic brakes and gear units.
─ The drives have a low and a high speed. The ratio of the two speeds is 1:4.
─ The drives have a modular construction of motor and gear unit to enable easy replacement.
─ The drives can be continuously adjusted in speed by the ABULiner frequency converter (optional).
─ The drives are connected to the motor protection switch in the crane panel.
─ The acceleration of the drives to high speed is switched on after a brief time delay. The drive is thereby prevented from running in a starting current for a longer period in inching mode (rapid switching back and forth). This would eventually damage the motor.
─ When braking from high to low speed, only two of the three phases of the drive are briefly switched to low speed. In doing so, the drive does not jerk to a halt but brakes softly. As a result, the load does not swing as greatly. This function controls the standard SU1 device.
─ When braking from high speed to a complete stop, for a short period prior to stopping the drive is switched to low speed. In doing so, the drive initially brakes dynamically. There is thus less wear on the brake lining and the lining does not need to be replaced so frequently. (Optional, control by the SU2 device)
─ The crane electrical system is stored in the crane panel on the end carriage.
─ The crane electrical system has the protection rating IP 55.
─ The crane electrical system is protected by regular fuse links in its main fuse.
─ The crane electrical system has mechanically interlocked directional contactors. This ensures that the drives cannot be connected to both directions of travel at the same time. This would cause a short circuit.
─ The crane electrical system is particularly service-friendly due to screwless terminals and wiring in cable ducts.
─ The crane electrical system is switched centrally through the main contactor. It is located in the crane panel. If the emergency stop button is pressed or if an emergency stop is triggered for other reasons, the main contactor switches off the power for all drives.
─ As a result of plug-in connections between all crane components, the crane electrical system is particularly maintenance-friendly.
The crane travel limit switches:
─ The crane travel limit switch is realised through a cross-type limit switch.
─ Crane travel limit switches are mainly used in the direction of the crane track end as motion restrictors.
─ The crane travel limit switches (option) can be designed with a braking and/or shut-down function.
─ The crane travel limit switches switch the crane to low speed with the braking function just before the end of the crane track. This prevents the crane from running into the end of the crane track at high speed and causing the load to swing.
─ The crane travel limit switches with the shut-down function (option) completely switch off the crane travel drive immediately before the end of the crane track. The shut-down function is particularly useful for certain safety switches.
For overhead travelling cranes with walkways:
─ The overhead travelling crane has a walkway to enable to safe maintenance of end carriages (optional).
─ The maximum load-bearing capacity of the walkway at any one point is 300 kg.
For 8-wheel cranes:
─ Neither main girder has an end carriage going all the way through, but each main girder has its own end carriage joined with a coupling bar.
─ Therefore, the crane does not have four but eight wheels, which reduces the load on the crane track and means that a smaller size end carriage can be used.