The Gearbox Under Your Mill Should Never Surprise You.Swiss Precision. Predictive Monitoring. OEM-Direct in Iraq.

One bevel and one planetary stage turn the horizontal motor axis into the vertical table drive, with the grinding table carried on the thrust bearing in the gear casing. The fixed ring gear of the planetary stage forms part of the casing — a unique design that gives the highest drive power available from a conventional two-stage gear unit, with lower energy losses and lower investment than a three-stage unit. Hydrodynamic sleeve bearings on the planet shafts, ISO Q4 tooth quality, internal emergency shoulders that limit table tilt, and large manholes for direct access to the bevel gear. The small series is built for coal mills, with all electricals to your anti-explosion requirements.

Two planetary stages with torque split — the first stage passes about 25% of the torque directly to the output flange, the remaining 75% goes through the second stage — so the four planets of the second stage need smaller wheels than a conventional serial arrangement. The result is the highest power density relative to the mill table diameter, with a performance range upwards of 8,000 kW. Hydrostatic thrust bearing with Babbitt-lined tilting pads, slide bearings with unlimited lifespan on bevel and planetary gears, dual-chamber lubrication, and a bevel pinion that can be adjusted or removed from outside while the unit stays under the mill.

A permanent-magnet synchronous motor with loss-optimised single-tooth coil, coupled directly and co-axially to the proven WPV planetary stage — the bevel stage of a conventional gearbox is eliminated, and with it the external main motor, the motor base, the alignment work after every inspection and the auxiliary drive. The frequency converter gives infinitely variable mill speed, soft start-up, controlled emptying of the table and lower vibration when raw material grades change. External dimensions match a conventional gearbox, which makes it a drop-in option for replacement and upgrade projects. Constant torque over a wide speed range with consistently high efficiency.

The standard for centre-driven ball mills since 1966, driving hundreds of raw and clinker mills worldwide. Two co-axial planetary stages with three planet wheels each and an internal toothed coupling between them deliver power efficiency above 98.9% with the fewest possible rotating parts, tooth contacts and bearings. Case-hardened, ground tooth flanks with profile correction; slide bearings with infinite lifetime; ZCF low-speed and ZEXF high-speed toothed couplings in the standard scope, with electrical insulation against bearing electro-corrosion. The vertically split casing lets the first stage slide towards the motor for full internal access without moving anything else.

A three-stage parallel-shaft gear driving the ball mill directly through two self-aligning output pinions; mechanical torque split guarantees equal load on both pinions and full tooth contact on the girth gear. The symmetrical casing installs on the centre line or 40° below the mill, cutting foundation height, construction cost and vibration sensitivity. It is detachable from its foot, can be flipped and run in reverse, and carries two independent lubrication circuits — a clean closed circuit for the fast gearing and bearings, an open one for the girth gear — which together extend lifetime by around 40%. Designed as a replacement for side drives of any original manufacturer: foot and guard interfaces are customisable, and the existing lube unit, couplings and auxiliary drive are reused where feasible.

Fabricated girth gears with forged gear rims on electro-welded bodies — a uniform, homogeneous crystal structure through the whole toothing, so the hot tears, porosity and shrinkage of cast rims are excluded. More than 50 years of forged-ring expertise and AGMA membership behind the rating calculations. Pinions made to match: self-aligning, spur, helical or double-helical, bored or integral, through-hardened, carburised and ground or induction-hardened, with MAAG’s own patented heat-treatment processes. Full NDT: ultrasonic, magnetic particle and penetrant testing to UNI EN ISO, AWS, ASTM, ASME and DIN.

Standard gearbox monitoring compares bearing temperature with a maximum and only catches large changes — by then you usually have a few weeks at best before total breakdown. MAAG CMS continuously measures oil particle content, vibration, temperature and operating parameters through sturdy sensors at the critical points, streams them to a secure cloud and puts MAAG specialists on watch, so wear is detected months ahead. Supplied and commissioned with new units, or retrofitted on site to a running gearbox, with training on hardware and software, remote surveillance and periodic expert reports with maintenance recommendations.

The bevel set is the most critical part of a WPU gearbox, and a broken one has no repair solution: a new set takes six to eight months to deliver. MAAG’s answer is a complete bevel stage — bevel set, bearings and internal coupling shaft — delivered ready-adjusted and assembled, mounted with eight bolts and erected within seven days, with no tooth-contact adjustment on site. Built to the latest MAAG standard with an eccentric, wear-resistant bearing sleeve and optional CMS instrumentation. The old stage is refurbished afterwards and stored as your emergency spare. MAAG calculates 80,000 hours of bearing lifetime and recommends a gearbox overhaul at that point — planned to match your market, not forced by a failure.