Innovative motorised torque arm improves reliability and compactness in speed reduction applications

A brand new motorised version of the Dodge torque-arm shaft-mounted speed reducer from Baldor Electric Company will make its European debut at Hillhead 2010. (22/24 June 2010 GB) The product provides a breakthrough in compact and robust speed reduction, and complements Dodge's renowned belt-driven speed reducers.

The Dodge Motorized Torque-Arm II shaft mounted speed reducer is a right-angle gearbox with an IEC flanged motor interface, specified for use with two-pole or four-pole motors. A choice of 12 helical gear reduction ratios and three case sizes allows the unit to deliver a wide range of speed reductions from 18:1 to 75:1 for class 2 applications from 1.5 to 55 kW, with very high efficiencies up to around 95%.

The new Motorized Torque-Arm II (MTA) has been optimised for robustness, offering considerable advantages over comparable gearboxes designed in accordance with European design practices. The reducer is rated to meet the 6010 AGMA (American Gear Manufacturers Association) standard. This specifies a 5000 hour bearing life, approximately twice as long as comparable DIN design specifications.

Numerous other reliability-enhancing features include the use of heavy-duty tapered roller bearings instead of ball bearings, and a novel input pinion shaft with straddle-mounted bearings on both the motor and gearing sides. This latter construction combats any overhang stress resulting from a poorly mounted motor, and additionally allows the gearbox to be offered in a sealed form that protects the gears against any contaminants during any installation or maintenance operations at the motor input.

Premium HNBR (hydrogenated butadene nitrile rubber) seals are fitted as standard for extra protection, and the MTA is designed to be used with Dodge twin tapered bushings - a patented design that provides a sturdy, concentric grip of the driven shaft on both sides of the reducer. This eliminates the wobble and fretting corrosion normally associated with single-bushed shaft mounted reducers.

"This is the first AGMA rated right-angle motorised torque arm reducer on the market we believe, and it provides an interesting alternative to conventional gearboxes wherever space is at a premium, and robustness is critical," says Charles Gubser of Baldor Electric Company. "We expect it to be of considerable interest to OEMs in machinery sectors including conveyors, and mixing and milling equipment dealing with harsh materials and in heavy-duty bulk handling applications."