New Bosch e-axle integrates motor, power electronics, transmission; mass production in 2019
02 September 2017
Leveraging its experience with electromobility components, Bosch has developed a new generation electric axle drive, or e-axle. The motor, power electronics, and transmission form one compact unit that directly drives the car’s axle. This makes the powertrain not only far more efficient, but more affordable as well.
Bosch has had electric axle drives in the market since 2012 (in the Peugeot 3008 and Fiat 500e, for example), but the power electronics was not fully integrated into them. With the new generation of the electric axle, Bosch is in the development phase, and is in contact with automakers from around the world. More precisely, samples of the electric axle are ready for use, and are currently being tested. Start of production is planned for 2019 at the latest.
With its e-axle, Bosch is applying the all-in-one principle to the powertrain.— Dr. Rolf Bulander, member of the board of management of Robert Bosch GmbH and chairman of the Mobility Solutions business sector
The components are very flexible, which means the e-axle can be installed in hybrids and electric cars, compact cars, SUVs, and even light trucks. Economically speaking, the e-axle may turn out to be a major coup for Bosch.
|The electric axle drive system. Bosch has combined three powertrain components into one unit. Click to enlarge.|
On the world’s roads, there are already more than 500,000 electric and hybrid cars fitted with Bosch components. Bosch thus has many years of experience in the manufacture of electric motors, axle drives, and power electronics. The expertise it has gathered in the process is now bearing fruit in its newly developed electric axle. With this component alone, Bosch is hoping to generate sales running into the billions.
As Bosch customizes the powertrain to each automaker’s requirements, customers no longer have the time-consuming task of developing new components. Bosch already has a flexible, globally applicable manufacturing concept for this component. The concept guarantees that each customer will get a customized solution that can be quickly integrated into its manufacturing operations.
The e-axle’s USP is its high level of versatility, which means it can be adapted to many types of vehicles. All the customer has to do is state what performance, torque, and installation space they require, and Bosch then optimizes the rest of the powertrain to fit these parameters. In this way, a complete, customized powertrain can be delivered directly to an automaker’s assembly line.
The powertrain can deliver between 50 and 300 kW, and is therefore also capable of powering large vehicles such as SUVs completely electrically. Torque at the vehicle axle can range from 1,000 to 6,000 N·m. When installed in hybrid and electric vehicles, front- and rear-axle drive is possible.
An electric axle delivering 150 kilowatts weighs roughly 90 kilograms, and thus far less than the combined individual components used so far. Compared with competing products, the distinguishing feature of the Bosch electric axle is an especially high peak performance combined with a high level of continuous performance, the company claims. In other words, the electrical powertrain can accelerate better and maintain a high speed for a longer period. To achieve this, Bosch has not only redesigned the system as a whole, but also improved the motor and power electronics components.
Excellent: with this, you could electrify "everything", especially the back axle of a FWD car. Ideally, you could use this to hybridise loads of vehicles so their engines did not have to be used in built up areas.
I suppose it is all down to the cost, and the complexity of integration and where you put the battery and how large it needs to be.
I wonder could you use a diesel engine as a generator in such a way that it produces minimal pollution to avoid the need for a large battery (in a serial hybrid configuration).
Posted by: mahonj | 02 September 2017 at 08:50 AM
Next step: integrated per-wheel motor/reduction units with optional clutches, designed for mounting on the suspension arms to reduce unsprung weight. This would provide 4WD/AWD options with full torque vectoring, and clutch disconnects to reduce free-wheeling losses on the un-driven axle with 4WD deactivated.
I am warming to methanol over diesel. It allows a much greater power density and has no carbon-carbon bonds to nucleate soot. You can even recuperate exhaust heat to crack it to CO + H2, recycling energy back to the combustion chamber (at some cost in volumetric efficiency, but this is actually an advantage in part-throttle operation).
Posted by: Engineer-Poet | 02 September 2017 at 09:06 AM
Nowadays OEMs can contract with parts suppliers to provide most of the assemblies for autos, not just individual parts. Bosch is just such a supplier..an OEM is being redefined as where the bodies and individual assemblies are assembled. One wonders how much of a Tesla is Tesla made, same with Mercedes, etc.
Posted by: Lad | 02 September 2017 at 04:14 PM
I like "through the ground" hybrids. The back axle of a FWD CUV is a good place to put this. It provides AWD and better mileage.
Posted by: SJC | 03 September 2017 at 01:20 PM
Another elegantly packaged solution especially economical for universal simpler fitment and assembly, power and speed options will suit most standard commuter and ordinary duty applications.
Motor per wheel for razor sharp handling and other benefits or two speed will come later but duplication will come at a cost.
Posted by: Arnold | 03 September 2017 at 02:06 PM
@95KG + 5-10 for processors, for a working e-cars can afford many - 300kg plus - of battery before weight compares with the ICE powertrain, tank, fuel exhaust, structural mounts etc etc.
Of course Bosh have always been brand agnostic industry supplier with large market supply chain.
Posted by: Arnold | 03 September 2017 at 02:19 PM
Future clean Hybrids (FC + batteries) and new well designed e-AWD installed in a much lighter body + lighter accessories could have a much higher total efficiency than current diesels with much the same range.
Users with short trips needs and home charging facilities could buy hybrids with larger batteries and smaller FC. Users with frequent long trips could buy hybrids with larger FC and smaller batteries.
Posted by: HarveyD | 05 September 2017 at 01:51 PM