New hybrid plans to outmode current systems

GM-BMW-DaimlerChrysler Global Hybrid System (Photo: Group Hybrid Corporation)

The point is that hybrid technology is still open for improvement, and that brings us back to the system unveiled in Vienna.

According to the syndicate, the key advantages of its "avant-garde" system compared to "conventional" hybrid systems involve gains in combined (city and highway) fuel economy, dynamics and towing capability.

"Traditional hybrid systems typically have only one torque-splitting arrangement and no fixed mechanical ratios," the syndicate points out, adding that they are often called "one-mode" hybrids.

"Due to their less capable mechanical content," says the syndicate, "one-mode hybrids need to transmit a significant amount of power through an electrical path that is 20 percent less efficient than a mechanical path. This usually requires substantial compromise in vehicle capability or reliance on larger electrical motors, which can create cost, weight and packaging issues."

GM-BMW-DaimlerChrysler Global Hybrid System (Photo: Group Hybrid Corporation)

The syndicate has created a full two-mode hybrid system featuring four fixed mechanical ratios, within the two electric continuously variable transmission (ECVT) modes, to "reduce power transmission through the less efficient electrical path. Consequently, the electric motors are more compact and less dependent on engine size."

This combination of two ECVT modes and four fixed gear ratios is said to eliminate the "drawbacks of one-mode hybrid systems to allow for efficient operation throughout a vehicle's operating range, at low and high speeds. It also allows for application across a broader variety of vehicles. It is particularly beneficial in demanding applications that require larger engines, such as towing, hill climbing or carrying heavy loads."

You can see how this would appeal to a syndicate with a range of products that covers virtually every segment in the business, from micro-econo cars to giant SUVs and pickups to hulking luxury sedans to performance sedans to family sedans and everything in between.

GM-BMW-DaimlerChrysler Global Hybrid System (Photo: Group Hybrid Corporation)

On top of that, internal combustion engines can be used with relatively minimal alteration (another important point for keeping brand identity in place) because the full hybrid system "imposes no significant limitation on the size or type of engine."

Basically, it "enables the three global automakers to package internal combustion engines with the full hybrid transmissions more cost-effectively and offer the fuel-saving technology across a wider range of vehicles."

Initial applications are suitable for front-engine, rear- and four-wheel-drive vehicle architectures, the syndicate notes, but the full hybrid system has the flexibility to be used in front-engine, front-wheel-drive architectures in the future as well.

Basically, the four fixed gears overlay two ECVT modes for a total of six operating functions:

• input-split ECVT mode, or continuously variable Mode 1, operates from vehicle launch through the second fixed gear ratio
• compound-split ECVT mode, or continuously variable Mode 2, operates after the second fixed gear ratio
• first fixed-gear ratio with both electric motors available to boost the internal combustion engine or capture and store energy from regenerative braking, deceleration and coasting
• second fixed-gear ratio with one electric motor available for boost/braking
• third fixed-gear ratio with two electric motors available for boost/braking, and
• fourth fixed-gear ratio with one electric motor available for boost/braking.

GM-BMW-DaimlerChrysler Global Hybrid System (Photo: Group Hybrid Corporation)

According to the syndicate, "the result is trend-setting hybrid technology that provides superior fuel economy, performance and load carrying capability."

The full hybrid system has an overall mechanical content and size similar to a conventional automatic transmission, says the syndicate, "yet this full hybrid transmission can operate in infinitely variable gear ratios or one of the four fixed-gear ratios."

Finally, a "sophisticated electronic control module constantly optimizes the entire hybrid powertrain system to select the most efficient operation point for the power level demanded by the driver."