General Motors announced that it will produce the new light-duty two-mode hybrid transmission at its Baltimore Transmission plant. GM will invest up to $118 million in new manufacturing equipment, new tooling and facility upgrades for the plant.
Production of the transmissions begins next year and will initially be used in GM’s new full-size SUVs, the Chevrolet Tahoe and GMC Yukon (earlier post), which GM will assemble at its Arlington, Texas plant.
GM opened its Powertrain Baltimore Transmission facility in 2000, where it builds the Allison 1000 Series automatic transmission. About 100,000 square feet—approximately a quarter of the facility—will be dedicated to producing the two-mode hybrid transmission.
GM, DaimlerChrysler and the BMW Group are co-developing the light-duty two-mode technology, modeled on GM’s multi-patented hybrid-electric diesel technology in urban transit buses.
The collaborative effort is working on three basic configurations of the Advanced Hybrid System: AHS-T for trucks; AHS-R for rear-wheel drive cars; and AHS-C for luxury/comfort cars.
In GM’s SUVs, the two-mode hybrid system will be mated to a 5.3-liter Vortec V8 with Active Fuel Management (displacement on demand) for a fuel efficiency gain of at least 25%.
Two-mode hybrid technology uses a variable transmission with two 60kW electric motors coupled to two gearsets to support two hybrid modes of operation. (Earlier post.)
In the first mode, at low speed and light loads, the vehicle can operate in three ways: electric power only, engine power only or in any combination of engine and electric power. In this mode, one motor acts as a generator, while the other provides drive (motor) power.
The second mode is used primarily at highway speeds. In addition to electric assist, the second mode provides full eight-cylinder engine power when conditions demand it, such as when passing, pulling a trailer or climbing a steep grade. In this mode, In the second, both motors selectively operate in motoring or generating modes depending upon the vehicle speed.
The second mode also integrates Active Fuel Management, cam phasing, and late-intake valve closure for more efficient engine operation in addition to the electric support.