Dodge Maxum XTR Concentric Gear Reducer, Sizes 50-130

Concentric gear reducer for high torque in a compact case

The Dodge Maxum XTR is a power-dense concentric reducer in which the input and output shafts share one axis, so the drive stays in line with the motor. Dodge describes it as a heavy-duty gearbox for severe applications with increased horsepower and torque ratings compared with competitive concentric reducers, designed to meet or exceed AGMA standards and offered as a drop-in replacement for the majority of installed concentric units. Nine case sizes, 50 to 130, cover fractional power to 1,166 hp and torque to 660,000 lb-in.

Reliability features include a purgeable seal system as standard, condition monitoring pads for accelerometers, and 100 percent factory performance testing. The internal housing design improves oil circulation and accepts inclined mounting positions.

Technical specifications

Rating comparison by size

The flyer compares these ratings against the main competitors at the 25:1 ratio; for size 50, for instance, it shows 33 hp and 29,500 lb-in against 28 hp and 25,500 lb-in. Dodge notes the table is an example comparison, and the engineering section carries full horsepower, thermal and overhung load tables.

Mounting and accessories

The reducer can be supplied as a separate unit, with a fabricated steel scoop for 143T to 445T motor frames, on a custom baseplate, with a top motor mount and V-belt drive, or on a slide base that simplifies belt and chain drive tensioning. A scoop package connects the motor and reducer economically in a compact footprint, and the newer scoop kits accept a range of NEMA and IEC frames with a multi-position coupling housing. Cooling is by a shaft-driven fan, an electric fan or a heat exchanger kit, and a backstop is available. Dodge states that accessories from legacy or competitive units must be replaced with approved Maxum XTR parts when upgrading, and that a shaft diameter or mounting footprint difference may need an adapter plate.

Ordering code and selection

A model reads motor frame, stages (D double, T triple), CR for concentric reducer, configuration (S scoop, B baseplate, T top motor mount), case size, nominal ratio and accessory codes BS backstop, G grid coupling, R Raptor coupling, HE heat exchanger, CF cooling fan, SB slide base and EF electric fan. Examples in the catalogue are DCR-100-11.4-BS for a separate size 100 double-reduction unit with a backstop, and part numbers such as DCR50-5.06 (268704). Confirm before ordering: required service factor from the AGMA-adapted table, thermal rating, motor frame, output shaft loads and direction of rotation for any backstop.

Documents and quotation

The attached PDFs are the Dodge Maxum XTR flyer and the Maxum XTR engineering catalogue. Related drives are listed under Couplings & Shaft Locking Devices. Send the machine, power, speed, ratio and mounting for a quotation.

How the Maxum XTR Concentric Reducer Works

In a concentric (in-line) reducer the motor drives the high speed input shaft, and power passes through two (double reduction) or three (triple reduction) single helical gear stages before it reaches the low speed output shaft on the same centreline. Each stage multiplies torque and divides speed by its own ratio, and the product of the stage ratios gives the nominal ratio stamped on the unit. Because the Maxum XTR gears are case carburized and crown shaved or ground to an ellipsoid tooth form, the load is carried in the strongest part of the tooth and tooth end bearing is avoided. Gears and bearings are splash lubricated from the oil sump with a quality petroleum base oil containing rust and oxidation inhibitors, and O-ring sealing with steel shims replaces gaskets so that bearing settings do not drift through gasket creep.

Maxum XTR Selection & Ordering Guide

The Dodge engineering catalogue sets out a step-by-step selection procedure that our team follows when confirming a Maxum XTR code:

• Service factor – choose it from the AGMA-adapted table for the driven machine and the hours of operation per day. Engine-driven installations need the conversion table for single or multi-cylinder engines.
• Equivalent load – multiply the absorbed horsepower or torque by the service factor.
• Ratio – divide input rpm by required output rpm and pick the closest AGMA nominal ratio.
• Unit size – read across the horsepower or torque table at the actual input speed (for example 1,750 or 1,170 rpm) until the rating equals or exceeds the equivalent load.
• Thermal rating – compare the actual power with the thermal rating with and without fan. Catalogue cooling requirements assume 80°F (27°C) ambient at sea level, so hotter sites need the ambient adjustment factors.
• Overhung and thrust loads – correct any sprocket, sheave or pinion load for its distance from the seal cage with the load location factor, then check it against the overhung load capacity at the shaft speed.
• Dimensions – confirm shaft diameters, footprint and weight on the size pages; the catalogue includes a Maxum to Maxum XTR dimensional comparison for upgrades.

Installation & Maintenance

Choosing the motor mount

Dodge gives clear guidance on mounting. The scoop mount is a soft mounting that isolates the reducer structure from motor vibration and is designed for a constant speed motor at 1,750 rpm; it is not recommended for variable speed AC or DC drives. The top motor mount saves floor space and allows output speed adjustment through the belt drive, but it is also intended for constant speed motors. The HD baseplate is a hard mounting that minimises resonance and is recommended where the motor weighs more than the reducer or 700 lb, and for variable speed AC or DC applications regardless of motor weight. Factory-aligned baseplates must still be rechecked for alignment on site before start-up.

Routine care

• Check the oil level at the sight plug and inspect the magnetic drain plug for wear particles at each oil change.
• Purge the auxiliary seal grease cavity in dusty or wet areas to keep contaminants away from the HNBR lip seals.
• Use the condition monitoring pads for periodic vibration readings, and the optional pitot tube for dynamic oil sampling.
• Fit a holding device on the driven equipment where a load could back-drive, as Dodge requires, and follow the Dodge instruction manual for oil grade and change intervals.

Typical Applications in Oman & the GCC

The Maxum XTR is suited to conveyors and bucket elevators in cement plants and quarries, aggregate and mining equipment, mixers and agitators, water and wastewater treatment drives such as scum breakers and clarifiers, and general process machinery in the Sohar, Duqm and Muscat industrial areas. High summer ambient temperatures in the region make the thermal rating check and the cooling fan or heat exchanger options especially relevant.

Why Source the Maxum XTR from Seven Star LLC

Seven Star LLC supplies Dodge power transmission products across Oman and the GCC. Send us the nameplate of the existing reducer or the application data, and our team can help confirm the correct Maxum XTR size, ratio and accessory codes before you request a quote.