Detailed Look At How Voltec Is Employed In 2016 Chevrolet Malibu Hybrid
The 2016 Chevrolet Malibu Hybrid is a non-plug-in, so it normally would not catch our gaze – but it utilizes second-generation 2016 Chevrolet Volt Voltec powetrain to achive its 46 mpg fuel economy…so it’s worth a look.
Green Car Congress recently released a detailed description of the Malibu Hybrid powertrain, and a comparison to the Volt, based on a SAE “Development of Hybrid-Electric Propulsion System for 2016 Chevrolet Malibu” article.
A common system in both cars is the transmission architecture, with two electric motors and changes to optimizations in a different application. (In case of Malibu Hybrid, there are also changes in the type of rotor of one of the motor)
The new Chevy Malibu uses larger 1.8L engine and smaller battery from Hitachi (1.5 kWh).
“Voltec drive unit. The drive unit is a transaxle configuration comprising transmission gearing and clutches; hydraulics; electric machines; and integrated power electronics. The basic layout is an on-axis design which is similar to GM’s 6T40/45 family of small-car front-wheel drive automatic transmissions. The center distance and vertical drop between the engine and output axes were designed to be common; this design approach enables the use of a common chain transfer design and final drive gearing, which provided a wide range of final drive sprocket and planetary gear sets allowing an effective final drive ranging from 2.64 to 3.50.
The transaxle includes two electric machines coaxial with the input shaft as well as an integrated Power Inverter Module which connects via busbars to the motors. The Power Inverter Module and motor stators are common between the EREV (Volt) and HEV (Malibu) versions. However, the transaxles were designed with unique rotors specific to the application. The stators utilize a bar winding design, while the rotors are two barrier interior permanent magnet designs using NdFeB magnets.”
Drive Unit Specifications Comparing Volt EREV and Malibu HEV applications Volt EREV Malibu HEV Gear ratio, EV mode A: 2.87
Modes, engine on 3 (Low, Fixed Ratio, High) Modes, engine off 2 (1 Motor EV, 2 Motor EV) 1 (1 Motor EV) Final drive arrangement Chain transfer and planetary gear reduction Planetary gearsets 2 Rotating clutches 1 plate clutch Brakes 1 plate clutch, 1 OWC 1 plate clutch Motor A type Distributed bar wound, Ferrite magnet Distributed bar wound, NdFeB magnet Motor A peak power 48 kW 55 kW Motor B type Distributed bar wound, NdFeB magnet Motor B peak torque / power 280 N·m / 87 kW 306 N·m / 76 kW Effective final drive ratio 2.64 Power electronics integrated Pumps 1 electric motor driven Total system mass 119 kg 116 kg
source: Green Car Congress