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YES! There is an all-new heavy gantry crane technology that is designed specifically to allow builders of heavy gantry cranes world wide, the opportunity to offer an entirely new range of gantry travel capabilities to their customers by eliminating the restrictions of in-floor rails.
Wheelift Systems offers a new technology in gantry trucks that allow heavy gantry cranes to travel both linear and lateral virtual paths. A single gantry can now service several side by side assembly lines. The gantries can also travel around radiused paths, as well as having the entire gantry crane rotate on center.
The heavy gantry crane trucks are fully self-contained with a 480V, 3PH, diesel generator (Or whatever voltage is common to the country of application) that is sized to handle gantry crane travel as well providing the crane builder’s specified power requirements for hoisting and trolley travel. Actually, the gantry crane would typically have the capability to run both off onboard generated power and/or being plugged into shore power.
VIRTUAL PATH inertial guidance is typically accommodated by a solid state gyro based guidance system. The heavy gantry crane can be customer programmed to follow a series of AUTOCAD layout VIRTUAL paths through his operating area. Tiny referencing magnets are imbedded in the operating surface along the desired travel path on fifteen foot (5 meter) intervals. This capability provides the ultimate in flexibility to the end user. He may change his travel path requirements at any time to accommodate changes in his product assembly operations.
Each of the Wheelift truck axle assemblies has the capability to articulate +/- 4 degrees laterally to accommodate severe surface undulations and drainage slopes. And further, each axle has the capability to rotate on-center for all directional computerized steering. Each Uniload axle assembly has a fluid center column that allows it to share its load equally with every other axle in the heavy gantry crane’s system, regardless of severe undulations in the operating surfaces.
For heavy gantry crane truck applications, Wheelift’s Uniload® axle assemblies are available in three size ranges starting at 30,000 lbs (13,600 kg) per axle. The choice of gantry axle sizing is generally based on the application’s operating parameters and involves considerations of wheel loading and space available. The tires are typical 95 durometer solid urethane and designed to operate in abusive environments. Typically, each truck would have four to eight or more Uniload axle assemblies.
The Wheelift “SynchroSteer” computer handles all of the complex geometry for steering every axle independently. The gyro-based inertial guidance system provides exact straight line travel in both linear and lateral travel modes. Predetermined radiused travel paths also can be programmed to accommodate precision travel around simple radius turns or complex serpentine paths. A gantry crane operator with a wireless controller regulates the travel speed and direction along any of the predetermined travel paths. The gantry crane operator may not drive off, or leave, a predetermined virtual travel path. A secure system is provided that requires trained and certified operators to have key access, plus a unique five digit security code to be able to operate the gantry crane.
Lateral travel to move to adjacent parallel assembly lines, can only be accomplished at specific locations that are clear of the assembling products.
Wheelift Systems furnishes complete pairs of trucks that are custom designed and built to bolt directly to the crane builder’s gantry legs. The heavy gantry crane’s truck assemblies are specifically designed for each application with the design being coordinated to meet the crane builder’s exact design and operating requirements. The trucks would typically include an appropriately sized diesel engine/generator package mounted on one of the truck assemblies. Each truck would have its own hydraulic power pack (HPU) to independently accommodate equalized suspension for the gantry crane. The trucks would be furnished with a complete electronic travel control system, while the hoist and trolley electrical panels and their controls are furnished by the crane builder.
The equalizing fluid suspension also is computer controlled to accommodate off-center and shifting centers of gravity. Each truck is divided into two quadrants, and pressure transducer measure the required system pressure for each, then calculates and displays the loading on each leg. The control screen displays the gantry's entire dead load and live load conditions on a real time basis.
The system requirements and most of the costs are the same for both light load and heavy load applications. Therefore, these systems have a definite applicability threshold in terms of capacity and the customer’s NEED for the added flexibility. It is the cost factor that limits their use to only to VERY heavy gantry crane applications.
For more specific foundation information on just what this unique and revolutionary new gantry crane technology is based on, please go the www.heavyagv.com website. There you will find detailed information on the related heavy transporter technology on which these new gantry crane components are based.
