InfraStructures - May 2010 - New Allison 6620 Off-Highway Automatic Transmission

New Allison 6620 Off-Highway Automatic Transmission

A raft of enhancements for Allison’s 6000 Series has led the leading producer of commercial duty, fully automatic transmissions to release a new 6620 transmission at bauma 2010. New hardware and software upgrades for the transmission used in rigid dump and specialist mining trucks up to 70 t as well as stationary pumping, drilling and winch applications, will enhance durability, lower operating costs and simplify maintenance.

Available in the second half of 2010 and replacing the 6610, this proactive design upgrade responds to changes in engine characteristics that are increasingly prevalent in the sector. Greater use of digital control for engines delivers sharper torque “response” through the driveline, necessitating upgrades to protect the drivetrain.

“We have made detail improvements throughout the product to further extend overhaul intervals and increase durability,” says Brian Reusser, Allison’s off-highway product manager. “These include design, manufacturing and material upgrades.” For the flywheel, the use of finite element analysis (FEA) identified an opportunity to modify fillet radii and introduce heat treatment and reduce stress. Case hardening and nitriding other interfacing components such as the turbine shaft and hub, together with increasing the shaft’s diameter, is expected to increase their fatigue durability by over six times. Extensive in-field comparative testing has identified a significantly more durable bronze-based material for use in the lock up clutch.

The core design of the Allison Off-Highway range of automatic transmissions, trusted by mining, quarrying and construction operators for many years has also received crucial software updates. Being part of this transmission family, the 6620 will feature a new CEC3 electronic control system when available that includes an extended CAN messaging set (J1939 protocol) and other electrical interface upgrades. This translates into advantages for both OEMs and end-users. Manufacturers will benefit from an easier and higher level of integration with the vehicle architecture, for example the choice of a proprietary shift selector as well as the Allison derivative will now be possible. The opportunity to “tune” the transmission to an operator’s specific requirement is now easier, permitting increased performance or economy depending on the duty-cycle or application.

Source: Allison Transmission, Inc.