PALO ALTO, California - The 2012 Buick LaCrosse is GM's first vehicle equipped with its new eAssist system, but it certainly won’t be its last.
eAssist is the new brand name for GM’s mild hybrid technology. It’s a totally new system, compared to the mild hybrid system found on the previous Chevrolet Malibu Hybrid and Saturn Aura Hybrid.
The next vehicle to get “eAssist-ed” will be the Buick Regal. But expect the technology to show up on a range of GM vehicles.
According to Daryl Wilson, lead development engineer for LaCrosse, the eAssist architecture allows it to be very scalable and adaptable to other models. “Because we don’t try to drive the vehicle solely on electrical power (just assist electricity), the system allows us to apply it to a wide variety of vehicle classes, everything from a V8 in a full-size pickup, to a small, four-cylinder engine in a mid-size car, to a vehicle with a small turbodiesel”.
GM prefers “eAssist” over “mild hybrid” terminology because it doesn’t want its message to be distorted by customers who have determined, in their own minds, that all hybrids must have certain attributes—like the ability to drive solely on electric power, or that a hybrid is dependent on a super-expensive, super-heavy battery. And according to GM, US customers are more focused on fuel economy results, rather than the in and outs of the technology created to provide it.
For the record, this is how Wilson defines the difference between a mild and a strong hybrid: “If I can operate and spin my electric motor independently of the IC engine, then I’m a ‘strong’ hybrid. If I can’t, then I'm a ‘mild’ hybrid”.
The eAssist is definitely mild because the electric motor is connected directly to the IC engine’s crankshaft, via the accessory drive belt. The electric motor only spins when the IC engine’s crankshaft spins, and vice versa.
Motor-Generator and Regenerative Braking
Several components make up the eAssist system. The under-the-hood parts include the motor-generator, a high-performance, liquid-cooled, compact, 15-kW induction motor (no brushes, no magnets). It’s mounted where the alternator would usually sit and is connected, as an alternator would, to the accessory drive belt.
As per standard practice, the crankshaft turns the accessory belt. But in the eAssist scenario, the motor-generator can also help “turn” the crankshaft (by that same belt), when drawing electrical juice from the trunk-located 115V lithium-ion battery pack.
eAssist is the new brand name for GM’s mild hybrid technology. It’s a totally new system, compared to the mild hybrid system found on the previous Chevrolet Malibu Hybrid and Saturn Aura Hybrid.
The next vehicle to get “eAssist-ed” will be the Buick Regal. But expect the technology to show up on a range of GM vehicles.
 |
| Photo: Buick |
According to Daryl Wilson, lead development engineer for LaCrosse, the eAssist architecture allows it to be very scalable and adaptable to other models. “Because we don’t try to drive the vehicle solely on electrical power (just assist electricity), the system allows us to apply it to a wide variety of vehicle classes, everything from a V8 in a full-size pickup, to a small, four-cylinder engine in a mid-size car, to a vehicle with a small turbodiesel”.
GM prefers “eAssist” over “mild hybrid” terminology because it doesn’t want its message to be distorted by customers who have determined, in their own minds, that all hybrids must have certain attributes—like the ability to drive solely on electric power, or that a hybrid is dependent on a super-expensive, super-heavy battery. And according to GM, US customers are more focused on fuel economy results, rather than the in and outs of the technology created to provide it.
For the record, this is how Wilson defines the difference between a mild and a strong hybrid: “If I can operate and spin my electric motor independently of the IC engine, then I’m a ‘strong’ hybrid. If I can’t, then I'm a ‘mild’ hybrid”.
The eAssist is definitely mild because the electric motor is connected directly to the IC engine’s crankshaft, via the accessory drive belt. The electric motor only spins when the IC engine’s crankshaft spins, and vice versa.
Motor-Generator and Regenerative Braking
Several components make up the eAssist system. The under-the-hood parts include the motor-generator, a high-performance, liquid-cooled, compact, 15-kW induction motor (no brushes, no magnets). It’s mounted where the alternator would usually sit and is connected, as an alternator would, to the accessory drive belt.
As per standard practice, the crankshaft turns the accessory belt. But in the eAssist scenario, the motor-generator can also help “turn” the crankshaft (by that same belt), when drawing electrical juice from the trunk-located 115V lithium-ion battery pack.
 |
| Photo: Buick |