Gear Motors for Crane Used to Construct World’s Longest Cable-Stayed Bridge

The special design of Mostovik derrick crane equipped with a wind meter, a lifting height indicator, and an indicator display panel position in the elevator accurate.

For this particular application needs crane especially requirements. It will not only have to take and safe place panels weigh 300 tons, but it will have to work reliable, in extreme temperature. In the area of winter the temperature will drop to low - 30 ° C. To meet these requirements, Mostovik Crane Factory, an Altra Industrial Motion company, for the supply of suitable geared motor and gearbox.

Shaft, foot, face and flange solutions are all included. The terminal gearbox can be mounted in alternative positions rotated in 90 degree steps around the motor frame, providing for unparalleled integration possibilities.

Measure the ball or roller bearing, case hard forged and ground gear, and internal and external bar transmission to ensure long service life and low maintenance. A hard wear sleeve and spray ring in the rotor seal allows to reduce oil sump capacity, reliable lubrication and years of no leakage performance.
For absolute reliability, BF series geared motor is totally enclosed and seal IP65 against dust and water spray. Important in Russky island bridge application, gear motor also provides comprehensive corrosion protection.

Low operating noise, the output speed from 0.2 to 190 RPM, BF series geared motor design provides a inverter friendly easily integrated.
Bauer win the supply contract gear motor against fierce competition. And Mostovik crane is the key of the success of the bridge construction project, the absolute reliability is very important. Bauer quality reputation in some of the world's most demanding crane project is a key product choice, Mostovik crane factory.

Mastering Crane Breaking Advanced Technology can Reduce Loss

Many authorities begin to think about emergency brakes for High compensation claims when happened injury or cargo damage. Because this is the high torque side of the hoist drive train, it requires brakes of a much higher capacity than those installed between crane motor and gearbox. As an example, the main boom hoist on a typical 70 ton container crane would require two emergency brakes, each capable of generating a braking force of 119kN.

These brakes need to be “fail safe,” which means that a nest of powerful springs are used to generate the required force and hydraulic pressure in excess of 160 bar is needed to compress the springs in order to effect brake release.

This hydraulic pressure is provided by a small power pack which typically consists of a 1.5 kW motor mounted on a tank top driving a positive displacement pump. This discharges its flow through a check valve to an accumulator and is automatically switched off when the system pressure is reached.

Two solenoids are employed: one on the flow line into the brake and the other on the discharge side. In normal operation with the drive hoist energized, the discharge valve would be closed and the input flow valve open. This condition permits the oil to maintain pressure on the springs and effect brake release.

The solenoids are connected to the crane motor circuitry and when de-energized open the discharge valve and close the input flow valve. This immediately releases the oil from the calipers and arrests the input flow allowing the springs to force the pads against the flange of the drum.

Failure of the transmission drive or normal service brake will activate an overspeed switch mounted on the drum shaft. This will then trip the power supply and consequently automatically apply the emergency brakes.

An alternative to an overspeed switch is a “mis-matched” control which constantly monitors the crane motor speed relative to the drum speed. The ratio of these speeds will always be constant parameters determined by gear backlash.

Many new cargo handling cranes are installed with the latest in superior braking technology, making braking and load holding safer and more controllable.