Salient Features of SKYLINE Cranes

Structural Design

For design of girder & end carriages, the most critical structural components in an EOT crane, we use static calculation developed through our vast experience wherein major design considerations like horizontal stress, vertical stress, deflection at load and fatigue limits are checked simultaneously for deriving optimum section. The design also undergoes vibration analysis.

The crab – trolley structure is characterized by lighter weight due to efficient design – lesser structural members (base frames holding wheels and members holding rope drum-gear box & other winch components). The lighter crab helps reduce & optimize the girder & end-carriage weight further.

All major welding process in manufacturing is carried out by CO2 welding.

Main Hoist Unit

Made of precisely matched components, SKYLINE open winches satisfy the most stringent requirements of up-to-date crane engineering.

The open winch unit consists of:

  • A rope drum with cut grooves, flanges on both sides, mounted on self-aligning roller bearings arranged to meet structural requirements.
  • A helical geared hoisting gearbox with fabricated housing and a horizontal joint.
  • The torque arm is adjustable and stress-free.
  • The drive shaft of the gearbox is connected directly to the rope drum.
  • A squirrel-cage rotor motor as lifting motor (frequency inverter-controlled).

Hoist Motors

Squirrel cage, crane duty motors as per IS: 325 and operated through VFD.

Advantages

  • Over temperature detection of motors using 3 PTC thermistors.
  • Hoist motors standard with IP 55 enclosure and class F insulation with temperature rise restricted to class B.
  • Special insulation system suitable to withstand voltage spikes when run on VFD.
  • These motors have dual coated winding wire and vacuum pressure impregnation.
  • Special rotor design along with increased air gap between rotor and stator.

Hoist Shoe Brake

Advantages

  • Completely enclosed type protecting against dust and dirt and at par with IP65.
  • Hydraulic actuation of thruster thereby reducing power consumption.

Hoist Gear Boxes

Advantages

  • Extremely high service life due to hardened and ground gears in oil bath and results in quiet operation.
  • Horizontally split gearbox for reduced repair and maintenance costs.
  • Oil leakage is completely avoided.
  • These gear boxes have consistently high torque ratings with gear ratios in close progression.
  • Flange, foot and shaft mounting options available along with compact dimensions will ease the engineering of any lifting or hoisting application.
  • The housing from nodular cast iron ensures robustness even in the harshest environment
  • The class of precision the gear is machined into helps producing an extremely quiet and vibration-free operation.

Travel Geared Motors

Advantages

  • Shaft mounted on wheel axle with torque arm, which results in less vibration and no alignment problems.
  • Heavy and overhang Long travel platform is avoided. Compact in design and less mechanical losses.
  • Less power consumption due to use of hardened and ground gearboxes.
  • All rotating parts are covered inside casing hence considered safer than conventional drive with floating shaft.
  • Less maintenance required as floating shaft, shaft covers, geared couplings and its covers are not required.
  • Provision of manual brake release lever. Hence, the load can be removed from the danger zone in the event of power failure.

Wire Rope

Power form, 6 x 36 constructions and strength 1960N/mm2. Make – Usha Martin.

Advantages

  • Compact high strength wire rope with higher fatigue life than conventional wire rope.
  • High steel fill factor results in higher minimum breaking strength and smooth exterior strand surface leads to reduce the abrasion wear of pulleys, drum & rope.
  • Consistent Performance
  • Fully lubricated in manufacturing
  • Independent wire rope core

Travel Wheel

Forged wheel of C55Mn75 material, sorbitised to 300 – 350 BHN for depth of 10 mm

Advantages

  • Large wheel diameters ensure safe, reliable crane travel
  • Also, compensates for any possible crane runway tolerances
  • A long life and high overload capacity
  • Heat treated using our in house processes to provide a uniform contour hardness in the tread and inner flange wear surfaces, while maintaining a ductile core to resist shock loads.
  • Resistant to flange fracture or wear.
  • Designed to resist pitting and spalling.
  • Improves the life of your rail.

Frequency Inverter

SKYLINE uses inverter/VFD with specially designed crane software.

Features

  • Direct Torque Control (DTC) for dynamic travel and hoist drives
  • Increased IP 55 enclosure up to size R6Solutions for special environments
  • Automatic parameter identification for fast and simple commissioning

Advantages

  • Speed monitoring function
  • Torque proving & monitoring function
  • Torque memory function
  • Higher speeds at partial load (power optimization- optional)
  • Intelligent brake logic: Brake release contact evaluation