In progress
Contact information
e-Traction Europe BVVissenstraat 36
324AL Apeldoorn
T: +31 55 521 1111
F: +31 55 522 2366
@: info@e-Traction.eu
Frequently asked questions about TheWheel
To make the principles of our traction system as clear as possible, some frequently asked questions are listed.
Q: What type of hybrid is the e-Traction Whisper bus?
A: The Whisper is a plug-in series hybrid. The propulsion of the city bus is fully electric by means of two wheel motors powered by a lithium-ion battery. This battery is charged by a power source, such as a diesel generator within the vehicle. Charging by grid is possible if the vehicle is not in operation.
Q: Why install a motor in the wheel?
A: Because an electric motor that has to provide enough torque to drive a vehicle without gears has a large diameter. Building it inside the vehicle will take allot of space and is negative for your building flexibility.
Q: Is regenerative breaking the key to the high efficiency?
A: Regenerative breaking helps with getting a vehicle more efficient. But the key for the high efficiency is in the absence of a gear box; this enables higher traction efficiency. Because of this high efficiency, the diesel generator necessary to charge onboard batteries can be much smaller, which reduces fuel and enables the possibility for lower vehicle weight. All these factors make the e-Traction system highly efficient.
Q: How much fuel can be saved with TheWheel?
A: Depending on the type and size of the vehicle. A small passenger car can, by using the batteries alone drive approximately 90 kM. On most of the trips the generator will not be turned on. And a trip to the gas station will be rare. For our citybus with the generator on during operation, cut back on fuel consumption by more than 50% is reached. This means an improvement of 100%.
Q: the motors are close to the road. Is there danger for shocks and / or water ingress?
A:TheWhisper is now driving for 4 years with our city bus with the electronics fitted inside of TheWheel. Shocks and water have till thus far never been a problem.
Q: What types of batteries are being installed in the Whisper bus?
A: Batteries of valence are chosen because of there heigh reliability great bms system and for safety reasons. In the whisper busses, 30 u27-12xp batteries of 130Ah are used. In an upcoming project, busses will be delivered with 60 u27-12xp batteries.
Q: Why not use Boostcaps in city bus applications?
A: At this stage there a pack of 30 lithium-ion 12,8volt 130Ah valence batteries onboard The Whisper. These batteries can absorb all the energy that is coming from the wheels in normal breaking situations. For emergency braking mechanical brakes are used(demanded by law). Also, longer battery power is needed to drive zero emission, which the boostcaps can not provide.
Q: Steering by controlling the speed of the motor?
A: The Whisper buses already have a software differential that helps to steer the bus actively thru a corner. Regulations prohibit steering a complete vehicle with software instead of mechanically.
Q: Do the diesel engines of the Whisper buses meet the emission regulations of the U.S or EU?
A: The diesel engines meet the emission regulations of the EU.
Q: Why is a diesel engine generating the power for the battery?
A:.At this moment there is chosen for a diesel engine because of simplicity and infrastructure demands of bus operators. Although, any power source is sufficient as long as it can deliver 70kW/h to the batteries.
Q: Can other technologies be used for charging the batteries?
A: Yes every power source can be considered to supply the power to batteries of e-Traction vehicles. As long as it supplies 70kW/h (in case of a city bus). The Hytruck (small distribution truck) which is fitted with our wheels features a hydrogen stack to supply the power. But other power sources can also be used.
Q: Does higher unsprung weight affect a comfortable ride?
A: Total weight of the unsprung parts (wheelmotors, rims ,tyre and axle) are only 200 Kilo heavier than the unsprung parts (wheels, rims, tyre, axle housing, axles, differential) of a normal city bus . Passengers of the Whisper buses are very positive about the comfort of the bus because of the silence and smooth operation - as there are no gear shifts. Comfort is therefore at a higher level than normal buses.
Q: Can the batteries be charged at the grid?
A: Yes the e-traction system is actually a full electric plug-in hybrid. Which means it can be charged at the grid. The busses will be charged at night so the vehicle operator can use as much green produced electricity as possible. The aim is to use the generator as wise as possible and end the day with an almost empty battery.
Q: Do you have to remove the motor when there is a flat tyre?
A: no the tyre is mounted on a rim. The rim is mounted on the outside of the motor. When there is a flat tyre the vehicle operator can remove the tyre and rim and replace it or repair it.
Q: How far can the city bus travel on batteries alone?
A: Depending on different factors a standard Whisper bus can travel for about 1 hour in city use with 30 130Ah valence batteries. A bigger battery pack will be on the a next project to prolong driving time. For smaller vehicles e-traction tres to find the best balance between average driving time for a commuter and vehicle weight.
Q: Can I retrofit my own car with the e-traction Wheels?
A: Currently e-Traction is focussing on OEM's in the truck, bus and heavy duty vehicle market and the bigger SUV’s to proof the viability of its invention. Customizing a single small vehicle is an intensive engineering job, financially unattractive and will probably cost twice the original vehicle price.