MAAG™ LGD lateral mill gear drive

The LGD gear unit from FLSmidth MAAG Gear is based on state-of-the-art technology and enhanced the already tried and tested design which is available on the market. It was developed to save cost and space for mills with integrated side drive.

Lateral Mill Gear Drive LGD
  • Technical Description
  • Customer Benefits
  • Downloads

Technical Data

The success of the MAAG lateral mill gear drive is based on its design. It is positioned 40° under the mill which demands a compact type of construction and leads to lesser building and foundation costs as a lot of space is saved. 

Further advantages of the LGD are as follows:

  • Integrated oil system
  • Direct lube oil return from the girth gear to the integrated lube oil tank prevents contamination of oil
  • Minimum oil flow in the girth gear guard
  • A tooth safety factor of at least 2,3 (AGMA)
  • Calculated bearing service life of 80’000 hrs

One of the major benefits of the MAAG LGD drive system is the torque split between the two pinions. It ensures that the total torque to the mill is always equally distributed from both pinions. Any deviations in torque between the two pinions is automatically equalised by axial adjustment of the intermediate shaft triggered by the deviations in the axial forces. A crowned toothing between the pinion and the pinion shaft enables the pinions to self align. This ensures full tooth contact even at a smaller run out of the girth gear and compensates pitch errors. 

Gear Unit Types
LGD-18 to LGD-80 
Power range 3,000 to 10,000 kW


Additional Components

Girth gear

FLSmidth MAAG Gear offers girth gears in 3 different materials which all live up to AGMA standards of service factors and same mechanical specifications:

  • Cast steel
  • Ductile (nodular) cast iron
  • Forged and electro-welded steel

The material type is defined by customer requirements and environmental settings. Mostly forged and electro-welded steel is applied as this material structure excludes the risk of inclusions. Also structure defects such as gas holes, hot tears, sand and slag inclusions are avoided and the fabrication technology process excludes the need for patterns and risers.

Auxiliary Drive

The auxiliary drive is specially designed for the MAAG LGD lateral gear drive units. Its components are compactly arranged on a common frame. Therefore the auxiliary drive needs only a small and simple foundation. Also installation and alignment is simple due to the compact design. The auxiliary drive is engaged and disengaged via an overrunning claw-type clutch. A fluid coupling between the auxiliary drive motor and the auxiliary drive gearbox provides a smooth start-up.


Your reasons to choose FLSmdith MAAG Gear

The position of the side drive is combined with many additional advantages:

  • Low risk of vibration in the gear unit foundation
  • Easy installation
  • Easy access for service and maintenance
  • Easy replacement for rotating parts 


Further benefits are: 

  • Low foundation design, i.e. compact mill arrangement
  • Direct lube oil return from the girth gear to the integrated lube oil tank
  • Minimum oil flow in the girth gear guard, i.e. minimum contamination of the lube oil
  • Standardized gearbox
  • Girth gear with optimum physical properties in all directions
  • No macro or micro defects in the girth gear base material

MAAG LGD integrated side
drive system
World Cement, December 2011


Download brochure
FLSmidth MAAG Gear LGD lateral gear unit
Watch the technical animation about MAAG LGD