Do electric cars have pistons?


Electric cars seem to be the wheels of the future. As greater importance is placed on reducing carbon emissions, more countries especially the EU, have set a target to switch over and to encourage gasoline car drivers to switch to electric vehicles.  So far a total of nine counties are planning to phase out internal combustion engines on their roads by 2030.

I guess this leaves us thinking, are fossil-fuel-powered cars so bad? And what set them apart from their counterpart, electric vehicle? First of all fossil fuel-powered cars aren’t so bad, unless you are super eco-friendly then you would probably hold a different view. Internal combustion engines or fossil-fueled cars are not so different from each other, in fact, one thing car enthusiasts often wonder is do electric cars have a piston?

Well, to answer this question, we need to understand how electric cars work and no we do not need to call Elon Musk to walk us through that.

Do electric cars have pistons? Electric cars do not have a piston because electric cars do not operate using an internal combustion engine. They use an electric motor that works on the principle of electromagnetism.

But can a piston be fitted into an electric motor? Well, that is a funny thought, but NO, and I doubt electric cars will even need it. But let us look at how electric cars have evolved through history with or without pistons.

Brief History of electric cars

Electric cars didn’t just spring up in the 21st century, in fact, is an old technology that has been around since 1800, 1880 to be precise, that is the year the first electric car was manufactured, during this period electric cars were quite popular.

They outnumber steam-powered cars and gasoline-powered cars, because they do not need to be started by turning a crankshaft, and they were less noisy plus they move with less vibration.

Furthermore, electric cars soon became a luxury only the rich could afford it, so when Henry Ford began to mass-produce gasoline-powered cars that were far cheaper than electric cars and could also travel long distance because electric cars could not travel long distances and required charge every hour.

This clever innovation became the death of electric cars by the 1930s around 1990 the demand for electric cars began to rise again due to oil crises and a need for eco-friendly vehicles, now that we have understood where we are coming from, let’s find out what is a piston and whether electric cars need a piston.

What is a piston

A piston is a component of a cylindrical engine that moves to and fro inside the cylinder as a result of forces produced during the combustion or compression process.

These forces get transferred to the crankshaft, the crankshaft converts the linear motion of the piston into a rotational force.

How does a piston work?

A piston is a piece of aluminum alloy shape like a plunger like component that is housed inside a cylinder, a typical piston moves through four basic steps refers to as an internal combustion cycle.
The very first step in the process:

Intake stroke

This is when the air-fuel mixture is brought inside the cylinder, as a result, the piston is pulled down to allow the further flow of air-fuel mixture, after a while The intake valve then closes and the air-fuel mixture is sealed inside the cylinder.

Compression stroke

After the intake stroke, the next process is the compression stroke, this is when the piston moves back upwards compressing the air-fuel mixture, this sudden movement increases the pressure inside the cylinder then spark plug inside the cylinder sets the mixture on fire creating an explosion.

Power stroke

The next step in line is the power stroke, it converts the heat energy into mechanical energy, pushing the piston downward, this movement turns the crankshaft, therefore, causes the car to move forward

Exhaust stroke

Lastly, is the exhaust stroke, this forces the piston back upwards, therefore expels the leftover gas from the power stroke stage. The exhaust stroke is the final stroke and occurs when the exhaust valve is open and the intake valve is closed. Piston movement empties exhaust gases into the atmosphere.

I am sure by now you are starting to get the picture, the pistons majorly work inside an internal combustion engine, while any engine that goes through the whole four-step is called a four-stroke engine. Let us go ahead to find out if the piston is just an invention of the internal combustion engine or it has its place inside the electric car.

How does an electric car work

Electric cars no doubt are the wheels of the future, over the past few years the number of electric cars on the road have greatly increased in numbers to about 2.1% globally, so what makes the electric cars so great that it could take on the gasoline-powered vehicle. The major technology behind the electric car are:

  • Electric motors
  • Battery pack
  • Controller

Electric motors

Electric cars are made possible with the invention of Nikolas Tesla (induction motor), the induction motor has become an industry-standard, three-phase induction motors have become the established technology for cars.

Because they are significantly lighter and more compact in size than DC motors and use what’s known as three-phase alternating current. The induction motor is a three-phase four-pole electric motor that is made up of two parts;

  1. Stator
  2. rotor

Stator

From its name, it is the stationary part of an induction motor it is constructed with high-grade alloy steel lamination to reduce eddy current losses. It has three main parts, the outer frame, the stator core, and a stator winding. The outer frame houses the induction motor and protects the inner parts.

The stator core carries alternating magnetic flux to reduce hysteresis and the stator winding carries the three-phase winding, the good thing about induction motors is that its speed depends on the frequency of the ac three-phase supply, this speed is the motor speed which is as high as 20000 RPM,
N=120F/(|P).

Rotor

The rotor is the rotating part of the induction motor in which the current is induced by some form of transformer action from the rotating magnetic field. The rotor is also built of thin lamination of the same material as the stator.

To be precise the rotor is simply a collection of conducting bars short-circuited by end rings. These conducting bars are laminated.  They are slotted on the outer side to receive the conductors.

The rotor can either be squirrel cage or wound type, enough of the engineering gibberish, for now, what we have seen is why induction motors are a perfect fit for electric cars.

Induction motors are considered the most cost-effective and reliable motors in the industry because control of these motors is quite simple to implement. The fact that it’s brushless and has a simple design makes the induction motors a low maintenance motor. They have a lot fewer parts than a piston engine. But what powers the induction motors inside an electric car?.

Battery pack

Lithium-ion batteries have been a great invention since the dawn of time, the simplest way of explaining what a battery is, a battery is an energy storage device, just imagine a tank that stores water for later use, the tank does not produce the water it only stores it for later use just like a battery, it does not generate energy it only stores it.

Lithium is a highly reactive metal that is why it is used in batteries, a typical lithium-ion battery contains two electrodes called the anode and cathode immersed in an electrolyte – a conductive liquid or solid – and connected outside the electrolyte is a conductive wire.

When discharging, the negative electrode (anode) releases electrons that move along the wire and are captured by the positive electrode (cathode). This movement of electrons creates an electric current, which can then be converted to power a motor or electronic device.

Lithium-ion batteries are suitable for electric cars because they are lightweight and they have a high energy density, though newer research around lithium-ion batteries could really make internal combustion engine obsolete. This new battery created by researchers at Penn State university boasting of a battery that can charge an electric car to its fullest under ten minutes.

Controller

All cars have a control unit, some manufacturers call it brainbox, but it performs the same functions of monitoring and coordinating engine and battery power, but in an electric car it determines the quantity of power coming from the battery that goes to the electric motor, just the right amount of power is required.

The controller supplies power to the electric motor every second depending on how much the driver presses down on the acceleration pedal, this creates a sensation of driving an internal combustion engine.

Nonetheless, electric cars are still fun to drive, they accelerate from startup better and easier because torque generation is very quick and accurate, hence electric motors can be controlled much more quickly and precisely.

Conclusion

Now its quite easy to see that, none of the components of an electric motor require a piston or is a piston, although there are still little components of an electric car I did not mention such as thermal system, charger port, inverter, etc. All these perform secondary functions in an electric car, nonetheless only gas-powered vehicles require piston but a piston has no use in an electric motor.

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