Double-girder bridge crane DMD 20 t / 17,7 m

PROJECT NAME: Double-girder bridge crane DMD 20 t / 17,7 m

 

INVESTOR: VA-TA metalik Ltd.

 

LOCATION: Kastav

 

YEAR OF PRODUCTION: 2020.

 

TECHNICAL CHARACTERISTICS:

  • maximum capacity: 20 t
  • bridge span: 17,7 m
  • lifting height: 6,35 m
  • lifting speed (frequency controlled): 4 - 1 m/min
  • hoist travel speed (frequency controlled): 20 - 5 m/min
  • bridge travel speed (frequency controlled): 40 - 10 m/min

 

TECHNICAL DESCRIPTION:

For the needs of the investor, the company VA - TA metalik Ltd., a project of a double-girder bridge crane was made, and it was produced and installed. The maximum load capacity of the crane is 20 t, and the span of the bridge is 17,7 m, while the lifting height is 6,35 m. The crane is mounted on the crane tracks in the production hall of the investor.

 

All working movements of the crane, namely: driving the bridge, driving the hoist and lifting and lowering the load, are driven by electric motor drives in two speeds controlled via frequency converters.

 

The crane is controlled from the floor by means of a radio remote control unit, and a suspended control unit with reduced voltage is installed as a backup control.

 

Due to the conditions and frequency of operation, the crane is classified in M5 operating class according to ISO 4301/1 (or group 2m according to FEM 1.001), for mechanisms.

 

Double-girder bridge crane consists of:

  • steel structure consisting of:
    • two main girders manufactured as box girders welded from sheet metal with a cross-sectional dimension of 1014 x 350 mm,
    • end carriages manufactured by MISIA, Italy, type: DG3130,
  • electric hoist manufactured by MISIA, Italy,type: XM750VS4H7 / 53,
  • electrical equipment.

 

The electrical equipment of the crane consists of:

  • crane drive motor with brake,
  • electric motor with brake for driving a hoist,
  • two electric motors with brakes for driving the bridge,
  • control cabinet,
  • limit switches for switching off the lift drive, the hoist drive and the bridge drive,
  • overload devices remote control radio,
  • suspended cable control unit with reduced voltage (reserve),
  • main switches, and
  • power and control cables within the crane itself.

 

In the end upper and lower position, the travel of the crane hook is limited by limit switches which exclude the direction of travel and allow the direction of travel only in the opposite direction. In the event of an overload (over 110% of the rated load), an anti-overload device is activated which switches off the lift drive. Then only the lowering drive is possible.

 

The hoist is equipped with a cross switch that switches off the hoist drive at both ends of the main girder before encountering rigid bumpers. In the same way, the drive of the bridge is switched off before encountering rigid bumpers at the ends of the crane tracks.

 

Rubber bumpers on the end carriages serve against a rigid impact into an obstacle. In the same way, the movement of the driving hoist along the main crane girder is limited.

 

The control unit has a red emergency stop button (mushroom-shaped) which switches off all crane drives.