MAAG™ WPU two-stage mill gear unit

The MAAG™ WPU heavy duty gearbox is designed to drive and support vertical roller mills. Starting from 1300 up to 5500 kW.

MAAG WPU two-stage Mill Gear Unit
  • Technical Description
  • Customer Benefits
  • Downloads

Technical Data

The compact 2-stage MAAG WPU bevel and planetary gearbox transmits the power from the electric motor to the grinding table. At the same time, it reduces the speed of the electric motor to the desired speed of the grinding table and changes the horizontal input axis to a vertical output axis. The WPU two-stage gearbox also supports the grinding table, mounted on the output disc. An external oil supply unit lubricates and cools the gearbox.

Casing with internally toothed ring gear
The MAAG WPU gear unit casing consists of a robust welded steel structure. The fixed ring gear is bolted to the casing so that reliable torque transmission is guaranteed. The grinding load including grinding table weight is transmitted straight to the foundation via the tilting-pad thrust bearing and the casing wall.

The toothed flanks of the sun pinions have both profile and longitudinal modifications to fully compensate for deformations of the sun pinion and planet wheels occuring under load. This method guarantees optimum tooth flank contact and very long life cycle.

MAAG WPU two-stage gear unit types
Large series:
Types range from WPU-54 to WPU-360
Power range from approx. 1300 to 5,500 kW

Small series (mainly for coal mills):
Types range from WPU-04 to WPU-48
Power range from 3,8 to 43 P/n (kW/rpm)

Additional Components

Auxiliary Drive / Maintenance Drive
Auxiliary or maintenance drives are available to meet your demands. The maintenance drive is placed between the mill motor and the gear unit, whereas the auxiliary drive is located behind the mill motor. The maintenance drive is a low budget drive for build-up welding on the mill table, or for convenient replacing of the lining plates. The auxiliary drive can be used when the mill starting procedure requires a start with its help. It is equipped with a claw type overrunning clutch and a fluid coupling. The fluid coupling provides a smooth start up while the overrunning clutch disengages automatically when the mill motor has started.   

Our standard supply includes a flexible coupling with the following features:

  • durable and reliable
  • low operating costs
  • almost maintenance free (no lubricants to change)
  • low vibratory loads in the drive train
  • relatively wide range for axial and radial misalignment   

Lubrication Unit
The gearbox is lubricated by a closed circuit oil system. The oil tank serves as a platform on which all the assemblies and components such as motor pumps (high and low pressure), switchable double oil filter, oil cooler and instrument panel are installed.

Your reasons to choose FLSmidth MAAG Gear

  • High operational reliability
  • Customer-specific design of gear units
  • Very high efficiency
  • Planetary gear stage and thrust bearing for grinding table with a very long  service life
  • Short installation time
  • Low-cost maintenance
Watch the technical animation about MAAG WPU
Download the article about WPU Gearbox replacement on a vertical roller mill
Download WPU two-stage gear unit brochure
FLSmidth MAAG Gear WPU two-stage vertical gear unit