Honda develops lightweight, compact hybrid powertrains

Japanese car maker Honda Motor  yesterday said it has developed a new lightweight and compact hybrid system, the Sport Hybrid intelligent dual clutch drive.

It said the new system was a lightweight and compact one-motor hybrid system optimised for small-sized vehicles. This new hybrid system will be the latest addition to Honda's 'Earth dreams technology' series of a new generation powertrain technology that realises both excellent driving performance and fuel economy at a high level.

Together with its Sport Hybrid Intelligent multi mode drive, two-motor hybrid system optimised for mid-sized vehicles, and the Sport Hybrid SH-AWD (Sport Hybrid Super Handling - All Wheel Drive), the three-motor hybrid system optimised for large-sized vehicles enabling independent control of torque distribution to both right and left rear wheels, the newly developed Sport Hybrid intelligent dual clutch drive will constitute the lineup of three different Honda Sport Hybrid systems that accommodate different vehicle characteristics.

"Honda will continue expanding the application of these hybrid systems based on vehicle characteristics," The company said in a statement.

The lineup of Sport Hybrid  systems includes:

One-motor Sport Hybrid intelligent dual clutch drive
In addition to top level fuel economy in its class, it has an acceleration g-force "more powerful than that of existing models as well as a rhythmic and linear acceleration feeling," Honda said.

This drive unit combines a newly developed inline 4-cylinder 1.5L Atkinson cycle engine with a 7-speed DCT system with a built-in high-output motor and a lithium-ion battery to improve efficiency by more than 30  per cent compared to a conventional one-motor hybrid system.

Its hybrid system for 1.5L engines, dual clutch transmission is the combination of the one-motor hybrid system and the engine realises sporty driving during acceleration and high-speed cruising by using the clutches to engage the engine.

"Highly efficient electric vehicle driving is realised during startup and low- to medium-speed cruising by using the clutches to disengage the engine. This system contributes to the improvement of fuel economy by increasing energy regeneration using the clutches to disengage the engine during deceleration," It said.

Two-motor Sport Hybrid intelligent multi mode drive / plug-in
Honda said the adoption of high-efficiency / high-output motors, both brisk acceleration with an EV-like driving feel and high fuel economy are realised at the same time.

This hybrid system realises the world's highest efficiency by combining a newly-developed engine dedicated for hybrid vehicles and an electric CVT coupled with two built-in motors and a lock-up clutch, along with a lithium-ion battery, and by optimally switching the driving mode among three different modes depending on the driving situation.

This hybrid system, which is also suitable as a plug-in hybrid system, will be installed to the North American version of the Accord, scheduled to be introduced to the market in January 2013.

The system switches the operation among the following three driving modes depending on driving conditions and the battery charge level:

"EV Drive" for driving by the electric motor using electricity from the battery and regeneration during deceleration.

"Engine Drive" for medium- to high-speed cruising with the engine and axle directly connected by a lock-up clutch and engine power is mechanically transferred to the wheels.

"Hybrid Drive" for urban driving and powerful acceleration using the motor with electricity generated by the engine.

Three-motor Sport Hybrid SH-all-wheel drive
The combination of a V6 engine and this high-output three-motor system realises acceleration performance equivalent to that of a V8 engine with fuel economy better than that of an inline 4-cylinder engine.

A new V6 3.5L direct-injection engine is installed in the front of the vehicle and combined with a newly-developed 7-speed DCT system with a built-in motor.

This Honda technology uses two motors installed in the rear to control torque distribution to the right and left rear wheels. Using independent motors for the right and left rear wheels, positive torque is applied to the outside wheel and negative torque is applied to the inside wheel, making independent control of torque distribution to the rear wheels possible without relying