Key Benefits

  • Highest power with cost-effective investment
  • Long service life and high operational reliability
  • Smart design and modern manufacturing deliver cost-effective results
  • Simplified maintenance

Innovative gear unit drives high output for your vertical roller mill

Modern vertical roller mills in the cement industry require gear units that are up to the challenge of handling higher performance densities and capable of transferring more torque. 

Current cement producers are also seeking optimum grinding table speeds, which determines the output drive speed of the gear unit. Increasing total gear ratios are the consequences of slower table rotation at the same gear unit input speed. Our MAAG® GEAR WPV with its masterful three-stage gear arrangement achieves all these aims – without compromising on reliability or ease of maintenance.

The triumph of double planetary gear


Introduced in 2007, the three-stage concept of this bevel-planetary gear unit is FLSmidth’s answer to ever-increasing mill sizes – and our MAAG® GEAR WPV has gone from strength to strength since its first implementation.

 

Unlike conventional two-stage gear units that require larger bevel wheel dimensions to increase power output, our WPV uses two planetary stages to move gear ratio from the bevel to the planetary stage. This adaptation reduces the size of the bevel wheel, keeping the gear unit compact and delivering the high-power output you need for your vertical roller mill.

 

The unique double-planetary gear with torque split in the WPV Gear Unit allows the unparalleled performance range upwards of 8,000 kW. The first gear stage passes about 25% of the torque directly to the output flange. With the remaining 75% in the second stage we accomplish the reduction in both tooth length and losses. The four planets in the second stage all use smaller gear wheels than typical gearboxes with two planetary stages in serial arrangement, allowing for high drive output in less space.

Planetary gear arrangement of MAAG® WPV gear unit explaining the torque split

Unique design for economical and reliable operation


Easy maintenance and compact design are normally competing interests, but we have managed to combine both in our MAAG® GEAR WPV Gear Unit. The double planetary gear stage provides impressive compactness, together with a loss reduction in relation to the torque split.


The thrust bearing arranged around the first planetary stage supports the mill table and absorbs static and dynamic loads from the grinding process. Each bearing pad is lubricated with high- and low-pressure oil and the pads are lined with Babbitt metal at the contact surface. The bevel and the planetary gears are equipped with slide bearings. These bearings not only provide unlimited lifespan, but also deliver smoother operation because of the higher damping compared to anti-friction bearings – increasing the overall availability of your vertical roller mill.


Large manholes in the lower casing part provide direct access to the bevel gear, letting the WPV gear unit remain in place under the mill during inspections and servicing and reducing any related downtime. Our WPV Gear Unit also simplifies maintenance by allowing you to easily adjust the tooth contact from the outside and quickly removing or adjusting the bevel pinion from outside the gear unit.

Three-stage bevel-planetary gear unit MAAG® WPV with labelled part

Dependably uncomplicated, with room for customisations


Despite the varying requirements of different mills and applications, the parts used in our MAAG® GEAR WPV have a high degree of standardisation. This consistency makes it an optimum gear unit solution for operating safety and reliability in the cement industry. Our WPV Gear Unit is available as standard solution or can be customised to suit your unique operational needs. The combination of the WPV’s high-grade bevel gear, innovative double-planetary gear and our unparalleled online condition monitoring lets you rely on common drive technology – even in high-power applications. With the WPV, you can implement new drive solutions without the need for complex control systems. 

All-around performance and ease from our three-stage gear unit

Highest power with cost-effective investment
Through its three-stage gear arrangement and the use of bevel and double planetary gear with torque split, our MAAG® GEAR WPV delivers optimised force-flow far above any other conventional drive system for vertical roller mills. It provides a simple and economical solution for your grinding process.
Long service life and high operational reliability
The three-stage gear arrangement of the MAAG® GEAR WPV and the thrust bearing for the grinding table give you dependable output and limited downtime. The internal emergency shoulders within the gear unit limit the tilting of the mill table and guarantee a longer service life for gearing and bearings.
Smart design and modern manufacturing deliver cost-effective results
While many manufacturers claim their products deliver the best performance, we demonstrate that with facts. The unique torque split in the double planetary gear stage and the high toothing quality in our MAAG® GEAR WPV demonstrably cut down friction losses – giving you measurable high-performance, cost-effective results.
Simplified maintenance
With unlimited lifetime slide bearings, easy-care flexible coupling, accessible bevel gear and the dual-chamber lubrication system that increases the lifespan of high-pressure pumps, our MAAG® GEAR WPV gear unit makes servicing simple – and costs you less to keep in good order.

Well-thought-out gear unit smoothly drives your vertical roller mill

Through carefully considering the power ranges and table diameters of various vertical roller mills, the design of our standardised MAAG® GEAR WPV fits with every process and under every mill. Customise your gear unit installation by taking advantage of our variety of auxiliary systems

Service engineer standing next to the bevel wheel in the lower casing part of MAAG® WPV

Low-maintenance, high-performance connections


The flexible coupling that comes standard with the MAAG® GEAR WPV Gear Unit is almost maintenance free, as it requires no lubrication. It also keeps vibratory loads low in the drive train and allows relatively wide ranges for axial and radial misalignment. These features combine to give you reliable function, with low operating costs.

 


Bring it all together with an auxiliary or maintenance drive


A maintenance or auxiliary drive that is tailored to your requirements rounds out the scope of supply for your WPV Gear Unit. The maintenance drive is placed between the motor and gear unit and allows you to rotate the mill table very slowly. This simplifies maintenance work at your vertical roller mill, including replacing lining plates or rebuilding surfaces through welding. The auxiliary unit is mostly used to start the mill when the breakaway torque is too substantial to start the motor directly. The fluid coupling of the auxiliary unit guarantees smooth acceleration and the overrunning clutch automatically disengages the auxiliary drive after the main motor starts.

Man standing in front of the world largest MAAG® WPV designed for 9.200kW

Oil supply unit keeps the gear unit running smoothly

 

The oil supply units for our vertical roller mill gear units and drive systems includes low-pressure pumps to feed bearings and toothings with filtered and cooled lubrication oil. If required, high-pressure pumps supply the oil for the thrust bearing from a separated compartment of the tank filled with filtered oil from the low-pressure part. Using only clean oil on the high-pressure side allows us to improve the lifespan of the pumps.

 


Beyond a basic condition monitoring system

 

All of our gear units and drive systems are equipped with unparalleled condition monitoring sensors. Normally, these types of sensors keep an eye on critical operating parameters like bearing temperatures, casing vibrations, etc. and trigger a mill shutdown in the case of exceedances.

 

Our condition monitoring system does much more. It lets you set up condition-based preventive maintenance that uses continuous monitoring and data analysis to detect wear and tear at an early stage. With this enhanced information, we help you plan maintenance and servicing in advance – reducing downtime and keeping your plant running smoothly.


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