How fast can the truck accelerate with Smesh-E-Axle?
A truck with Smesh-E-Axle pulls-away fast enough to keep up with the traffic and efficiently perform the task for which the truck is being used.
Fast acceleration leads to excessive wear and tear on tyres, road surfaces, batteries and motors. In addition, energy consumption is unnecessarily increased. Environment and efficiency both benefit from the Smesh-E-Axle.
And the truck drivers? They drive very relaxed thanks to shock free shifting gears under full load.
When will the Smesh-E-Axle be available on the market?
Before the Smesh-E-Axle is taken into production, we will first test, validate and demonstrate it more extensively under real conditions. The field test is scheduled for 2021.
Does the Smesh-E-Axle have regenerative brakes?
Yes. The Smesh-E-Axle is OEM compatible and uses the truck manufacturer’s regenerative brakes. An important additional advantage is that the Smesh-E-Axle shifts under full load during acceleration and braking. As a result, more energy is recovered than originally specified by the manufacturer.
That means more range, less maintenance and more safety.
Why is the Smesh-E-Axle more economical than other electric powertrains?
The Smesh-E-Axle has been designed with efficiency in mind. In our electric powertrain the motors and patented SmeshGear transmissions are integrated in the rear axle so that the entire powertrain is in one line. Angled gears are a thing of the past and all energy flows to the wheels in a linear movement. On top of that, even more efficiency enhancing innovations have been applied:
- Thanks to SmeshGear and smart motor management, the electric motors remain in the optimum operating range.
- Is the power not needed? Then one engine shuts down to further increase the eficiency!
- SmeshGear transmissions have an efficiency of 100% from 49 km/h.
- Fewer batteries and smaller motors are sufficient to achieve the desired performance.
- Increased braking energy regeneration thanks to shock free downshifting under full load.
In this way, the most efficient e-truck powertrain is created; and as far as we are concerned this will quickly become the new standard.
Why is the Smesh-E-Axle using two small electric motors?
We use two 105 kW permanent magnet axial flux synchronous motors which deliver the power in cascade to the heavy-duty truck. By integrating the motors into the e-axle we achieve an unparalleled efficiency.
The motors spin in parallel with the wheels as opposed to perpendicular, and this configuration eliminates parasitic loses caused by gearings and shafts in front of the rear axle.
Did you know that one 105 kW motor is more than powerful enough to keep a heavy-duty truck at speed?
That is why we only use both motors to accelerate, regenerate braking energy and drive uphill. Once the vehicle is at speed the surplus of power is eliminated by switching off one motor, which increases the efficiency even further!
The nominal power is 105 kW, so how much peak power do these motors produce?
They don’t because peak power destroys efficiency. If you boost the e-motor and double the power from 105 kW nominal to 210 kW peak, the energy consumption does not double but it increases fivefold! Instead we use our patented 8 speed SmeshGear transmission to create high torque to the wheels at low energy consumption.
Are gears useful when an electric motor can accelerate well from a standstill and can also run at high revs?
Contrary to popular belief, gears provide significant efficiency gains for electric motors.
Each vehicle operates at different speeds and the motor, both internal combustion engine and electric motor, has an optimal operating range at which the motor is strongest and/or most efficient. And that operating range also varies depending on the load. An example to clarify:
When you drive off, the greatest force has to be on the wheels. Fortunately, the electric motor is at its strongest there! Is that right? Yes, but not strong enough! An electric motor gives you all its power and torque from the moment you start, but there will have to be a mechanical deceleration. The disadvantage of that deceleration is that the top speed is lower and the high efficiency range suffers even more.
Imagine your vehicle weighs 40 metric tons, that’s a big mass to set in motion at once. The use of gears increases the torque until the vehicle moves. So gears ensure that the two working areas, ‘accelerate’ and ‘maintain cruise speed’, both have their own deceleration. This prevents damage, increases battery life, makes use of engine power more efficiently and opens the door for smaller engine capacity and more range.
More efficiency, more power and less wear and tear. This is why transmissions are also needed for electric motors.
How many gears does the Smesh-E-Axle have?
Did you know that a gear is actually decelerating? It sounds a bit strange, but a gearbox slows down the motor speed. The 1st gear slows down the most and the last gear slows down the least and because of this the vehicle accelerates.
The Smesh-E-Axle has a total of 8 gears, and why 8? Because it allows the electric motor to operate to the maximum extent in the optimum operating range with varying load and speed. An additional advantage is that the motor is only loaded at nominal power. In this way, the gears contribute to the increase of efficiency.
How does the SmeshGear transmission work?
SmeshGear is mechanical switching in a simple and reliable way without loss of efficiency.
The SmeshGear transmission has been developed to make it possible to customize a motor. This delivers the right power at the right time, resulting in better control and management of the truck. This technology is internationally patented.
How does the SmeshGear work?
Levers turn a small force into a large one. A gear wheel is actually a rotating lever and turns a small force into a large force (torque). When you pull-away, a compact gear system ensures that a large rotating force is created. And that without overloading the electric motor, which is better for the lifespan. The SmeshGear then ensures that this gear system is ‘switched off’, allowing a high speed to be achieved without any gear loss. This shutdown and activation of the compact gearbox is simply done during rotation, thus under full load during acceleration and braking. In practice you hardly feel a thing of it.
The basis of the SmeshGear transmission is a planetary gear system with an efficiency of at least 97.6%. If the transmission is not needed, it disengages the gear system by means of clutch plates (solar wheel and planetary carrier are coupled) and rotates the whole without friction, thus with 100% efficiency in the 1:1 position activated from 49 km/h.
Thanks to the SmeshGear, your vehicle will continue to perform optimal at maximum efficiency.
What is the Gross Axle Weight Rating (GAWR)?
The GAWR is the specific weight determined to be the maximum allowable that can be placed on the Smesh-E-Axle.
For the proof-of-concept axle we have calculated a theoretical maximum load of 16.000 kilogram.
The technical GAWR for the current version is 12.000 kg, more than enough considering the Dutch maximum allowed weight of 11.500 kg. Safety is key!
Future versions will be designed based on how much weight the axle needs to carry.
What is the life expectancy of the Smesh-E-Axle?
An electric powered truck is much less complex than a truck with a traditional diesel fuel engine. Electric contains far fewer moving parts so maintenance and repair according to the Bovag is 65% lower. We support that.
We guarantee that the Smesh-E-Axle will last 1 million kilometers and expect a technical lifetime of at least 2 million kilometers.
For which type of vehicles is the Smesh-E-Axle suited?
The Smesh-E-Axle is designed to electrify heavy-duty class-8 semi trucks. From local distribution to international transport and heavy haulage.
What is the effect on the unsprung mass (weight) of the truck?
Although the Smesh-E-Axle has integrated gears and motors, the total axle weight remains about the same as the standard rear axle of a heavy-duty truck. However, the total weight of the powertrain is reduced by more than 50%!
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