A state-of-the-art full hybrid system,
co-developed by GM, DCX, and BMW, was announced today, with production starting next year. The hybrid system combines
the electric motors with a fixed-gear transmission, allowing easy integration with a number of different engine
choices. The system is a so-called “two-mode” hybrid, since it incorporates both a low and a high-speed
electric continuously variable transmission mode. The system also incorporates four fixed gear ratios for a wider range
of optimum operation. The full press release can be found after the jump. The general audience often has a hard time
understanding exactly how a hybrid vehicle works, and this press release is definitely not helping the general
public’s understanding. I will withhold further comments on the system until I am actually able to understand how
it works.
[Source: DCX Media Site]
GM, DaimlerChrysler, BMW Premiere Unprecedented Hybrid Technology
Vienna, Apr 27, 2006
The
state-of-the-art full hybrid system, whose components are being co-developed by General Motors Corp., DaimlerChrysler
and the BMW Group for production beginning next year, represents a major automotive industry milestone due to the
unprecedented fully integrated combination of electric motors with a fixed-gear transmission.
As a result of
its low- and high-speed electric continuously variable transmission (ECVT) modes, the system is commonly referred to as
the 2-mode hybrid. However, the sophisticated fuel-saving system also incorporates four fixed gear ratios for high
efficiency and power-handling capabilities in a broad variety of vehicle applications. During the two ECVT modes and
four fixed gear operations, the hybrid system can use the electric motors for boosting and regenerative braking.
In summary, 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.
* Fourth fixed-gear ratio with one electric motor available for boost/braking.
The
result is trend-setting hybrid technology that provides superior fuel economy, performance and load carrying
capability.
The full hybrid system being co-developed by General Motors, DaimlerChrysler and the BMW Group
has an overall mechanical content and size similar to a conventional automatic transmission, yet this full hybrid
transmission can operate in infinitely variable gear ratios or one of the four fixed-gear ratios.
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.
Key Advantages
When
compared to conventional hybrid systems, this avant-garde hybrid technology, relying on both the ECVT modes and the
four fixed gear ratios, provides advantages 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. These systems are often called “one-mode” hybrids. Due to their less capable mechanical
content, 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 requires usually substantial compromise in vehicle capability or reliance
on larger electrical motors, which can create cost, weight and packaging issues.
General Motors,
DaimlerChrysler and the BMW Group have conceived a full hybrid system featuring four fixed mechanical ratios, within
the two 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 eliminates 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.
Existing internal combustion engines can be used with relatively minimal
alteration because the full hybrid system imposes no significant limitation on the size or type of engine. 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, but the full hybrid system has the
flexibility to be used in front-engine, front-wheel-drive architectures in the future as well.
Global Hybrid
Cooperation
General Motors, DaimlerChrysler and the BMW Group have formed a cooperative effort called the
Global Hybrid Cooperation, which is actively developing this next generation hybrid powertrain system. In an alliance
of equals, all three partners are pooling expertise and resources to jointly and efficiently develop hybrid technology.
Each company will individually integrate the full hybrid system into the design and manufacturing of vehicles in
accordance with their brand specific requirements.
In Troy, Michigan, the “GM, DaimlerChrysler and BMW
Hybrid Development Center” houses together engineers and specialists from all three companies to develop the
complete hybrid system and the individual components — electric motors, high-performance electronics, wiring, energy
management, and hybrid system control units. In addition, the “GM, DaimlerChrysler and BMW Hybrid Development
Center” will be responsible for system integration and project management.
A key factor in ensuring
optimum development is the focus on a flexible system design that can be scaled to the size, mass and performance needs
of the various vehicle concepts and brands. The extensive sharing of components and the collaborative relationship with
suppliers will enable the alliance partners to achieve economies of scale and associated cost advantages that will also
benefit customers. Currently full hybrid systems are under development for front- and rear-wheel-drive passenger cars,
and light-duty truck and SUV applications.
General Motors Corp. (NYSE: GM), the world’s largest
automaker, has been the global industry sales leader for 75 years. Founded in 1908, GM today employs about 327,000
people around the world. With global headquarters in Detroit, GM manufactures its cars and trucks in 33 countries. In
2005, 9.17 million GM cars and trucks were sold globally under the following brands: Buick, Cadillac, Chevrolet, GMC,
GM Daewoo, Holden, HUMMER, Opel, Pontiac, Saab, Saturn and Vauxhall. GM operates one of the world’s leading
finance companies, GMAC Financial Services, which offers automotive, residential and commercial financing and
insurance. GM’s OnStar subsidiary is the industry leader in vehicle safety, security and information services.
More information on GM can be found at www.gm.com.
DaimlerChrysler’s product portfolio ranges from
small cars to sports cars and luxury sedans; and from versatile vans to heavy duty trucks or comfortable coaches.
DaimlerChrysler’s passenger car brands include Maybach, Mercedes-Benz, Chrysler, Jeep®, Dodge and smart.
Commercial vehicle brands include Mercedes-Benz, Freightliner, Sterling, Western Star, Setra, Mitsubishi Fuso, Thomas
Built Buses and Orion. DaimlerChrysler’s strategy rests on four pillars: Excellent products offering outstanding
customer value, leading brands, innovations and technology leadership and global presence and networking. With 382,724
employees, DaimlerChrysler achieved revenues of €149.8 billion in 2005.
The BMW Group covers the BMW,
MINI and Rolls-Royce brands. The BMW Group is the only automobile company worldwide to operate with all its brands
exclusively in the premium segments of the automobile market, from the small car to the absolute top segment. The BMW
Group’s vehicles provide outstanding product substance in terms of aesthetic design, dynamic performance, cutting-edge
technology and quality, underlining the company’s leadership in technology and innovation. Today, with revenues of 46.7
billion euro, annual sales of 1.328 million automobiles (thereof 200,000 MINIs), 97,500 BMW motorcycles and with almost
106,000 associates, the BMW Group is one of the world’s ten largest automobile manufacturers.