Ag Equipment Intelligence

Deere to Launch Mechanical Transmission to Challenge CVTs

This week at the Agritechnica exposition in Hanover, Germany, John Deere is expected to launch a new transmission option as well as unveiling its smaller 6R tractors.

According to a published report in the U.K.-based publication Profi International, the new transmission option for Deere's 6R Series tractors "combines the power efficiency of a mechanical transmission, with the handling comfort of a continuously variable transmission (CVT)."

A CVT is a transmission that can shift steplessly through an infinite number of gear ratios. This contrasts with mechanical transmissions that offer a fixed number of gear ratios. The flexibility of a CVT allows the drive shaft to maintain a constant speed over a range of output velocities. This can provide better fuel economy than other transmissions by enabling the engine to run at its most efficient revolutions per minute for a range of vehicle speeds.

Deere is calling its new transmission DirectDrive. According to the Profi report, the 24-speed transmission uses dual or double clutch technology something that is already established in the prestige car industry. It uses an inner and outer clutch to control an inner and outer drive shaft so there is always a gear engaged and a smooth transition of power when increasing or decreasing speed.

The tractor maker is billing its new transmission as a cost-efficient alternative to existing CVTs and is aimed at larger arable farms and custom operators. The gearbox is designed for specific tasks and load conditions that require continuous power flow, such as plowing, hauling, PTO work and road transport. Deere says that savings of up to 10 gallons/kWh are possible when compared to a CVT.

DirectDrive uses a fully mechanical power flow. According to Deere, this results in a power efficiency improvement of approximately 4%, without compromising operator comfort and productivity. The new transmission will be an option on six-cylinder 6R Series tractors from 140-210 horsepower next summer.

— Ag Equipment Intelligence, November 2011