What Is A Flywheel? Its Diagram and Functions

A flywheel is one of the most important components of an automobile engine. It’s a mechanical device specifically designed to store rotational energy (kinetic energy). It’s proportional to the square of its rotational speed and mass. A flywheel is a heavy disc attached to the end of a rotating shaft that helps smooth out the engine’s power pulses and store energy through rotational momentum.

In this reading, we’ll explore what a flywheel is, its diagram, functions, and how it works.

Let’s get started!

What Is A Flywheel?

A flywheel, a heavy wheel, requires substantial force to rotate on its axis and resists changes in rotational speed due to its moment of inertia. By changing the stored energy on the flywheel, its rotational speed must be increased or decreased. That is, it keeps spinning until lots of force is applied. Furthermore, a great deal of kinetic energy is preserved when the flywheel rotates. This energy is later used to power up the vehicle when starting the engine or speeding.

Diagram Of A Flywheel

Flywheel

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Functions of Flywheel

Flywheels can be found in almost all types of automobiles, as they serve a variety of purposes. Below are the functions of the flywheel in an automobile engine:

Engine Balancing

Because the pistons are offset from the center of the crankshaft, vibration and wobbles occur. This is also because each piston fires at a different angle. The function of a flywheel in this situation is to suppress the side-to-side motion. This is achieved because of the heavy weight of the flywheel.

Engine Start

The flywheel plays another role while starting the engine. The gear teeth on the flywheel are attached to a starter motor. This starter motor is controlled with the car key, so when the car is started, the starter motor turns the flywheel. Immediately the engine spins, and the combustion effect continues to turn the engine. The starter motor’s Bendix gear retracts, allowing the flywheel to spin freely.

Drivetrain Stress Reduction

By stabilizing the engine’s movement, a flywheel can perform this additional function. It also smooths out the engine’s speed and reduces wear and tear on the drivetrain components. The flywheel also limits the wear between the transmission shaft and the driveshaft. These two are attached with a universal joint.

Engine Speed-Soothing

The crankshaft converts the piston movement into rotary motion, which is jerky as the power is generated. the rotational speed of the crankshaft is constant and the engine runs smoothly. This is because the mass of the flywheel applies inertia, which keeps the engine crankshaft spinning between each piston firing.

Weight Manipulation

The weight of a flywheel determines the performance of an engine. The weight is designed based on the performance of the vehicles. Heavier flywheels allow the engine to work under loads, which may cause the engine to bog down. Large trucks or trailers work well with heavier flywheels, while sports cars and some commercial vehicles work well with lighter flywheels.

Parts Of a Flywheel

A car flywheel is made up of several compact components that are necessary for its operation. They are as follows:

Mainbody or Disc

The central disc is the primary component of the flywheel in automobile engines. It is the major part that stores the rotational energy needed for this mechanical device’s functions, especially preserving the engine’s mass distribution and balance.

Outer Rim

The outer rim refers to the peripheral edge of the automotive flywheel, where the bulk of the mass concentrates. Typically, it weighs more than the internal body because it increases the flywheel’s rotational inertia, which improves kinetic energy transmission and maximizes energy storage. The rim also has teeth on the outside, which helps the engine start by interacting with the electric motor.

Ring Gear

Ring gear is the toothed wheel on the flywheel’s outside edge. Its main purpose is to assist with starting the engine by engaging the starter motor’s pinion gear, which rotates the flywheel and triggers the engine to crank.

Flywheel Cover

The structural protective barrier covering the entire system is known as the flywheel cover. A sturdy cover keeps the mechanical device shielded from the elements, ensuring that it maintains its structural integrity and is durable enough to carry out its intended functions.

Crankshaft Flange

The crankshaft edge is the flywheel area that connects to the vehicle’s engine crankshaft. The surface is usually machined and has tapped holes so that bolts and nuts can be used to fasten it and make sure it’s attached correctly.

Mounting Holes

The mounting holes are strategically placed holes in the flywheel. They are essential for fastening this mechanical component to the engine’s crankshaft with bolts and nuts

Axial and Radial Bearings

The axial and radial bearings are essential parts that enable the flywheel to rotate. They help to improve the more balanced and smooth operation of the vehicle by compensating for any imbalances in the axial (thrust) and radial forces. Also, they help to lessen the negative consequences of uneven forces by aiding in support and efficient load distribution.

Flywheel Construction

Car engines use flywheels composed of cast or nodular cast iron, steel, or aluminum. Flywheels made of composite material or high-strength steel have been suggested for use in car braking and energy storage systems.

The maximum amount of energy a flywheel can store per unit weight is a measure of its efficiency. This stored energy grows as the flywheel’s rotational speed or angular speed increases; nevertheless, stress increases as well.

Related: What Is A Propeller Shaft? Its Diagram, Parts, And How It Works

How A Flywheel Works

The flywheel works this way: it first stores the mechanical energy that the torque generates, and then it releases this energy by rotating the engine. Engine speed increases as mechanical energy is saved. The stability of the engine speed will be maintained in the appropriate manner when the mechanical energy is released. The machine can rotate steadily.

The flywheel receives mechanical energy in the form of torque, which increases its rotating speed. This makes it possible to store energy. Alternatively said, the flywheel rotates the mechanical load to preserve the engine’s rotational stability when it releases stored energy.

Types Of Flywheel

Here are the types of flywheels:

Solid Disc Flywheel

One type of flywheel is the solid disc flywheel. A cast iron single-flywheel threshing machine uses it. A flywheel hub and disc are part of the complete disc flywheel setup.

There are many different parameters that are used as inputs in the process of calculating the design of a full-disc flywheel. This includes the flywheel’s full-disc dimensions. Also, the function values that are obtained are computed.

Rimmed Flywheel

With the same weight and diameter, a complete disc wheel explodes significantly faster than a rim-type flywheel. A flywheel made of high-strength steel with a centrally thick conical disk can have a low weight and a large energy storage capacity.

High-Velocity flywheel

The high-speed flywheel in these types of flywheels spins at a rate of 30,000 to 80,000 revolutions per minute. The rpm of this can also be adjusted to 100,000. They require little upkeep and include magnetic levitation bearings. Depending on size and capacity, these are lighter than a flywheel that runs slowly. Compared to a low-velocity flywheel, they cost more.

Low-Velocity Flywheel

The low-velocity flywheel in these kinds of flywheels spins at 10,000 revolutions per minute. When compared to high-velocity flywheels, they are bulkier and heavier. In addition to not using magnetic levitation bearings, they do require periodic maintenance. A specific concrete structure is required to withstand their weight during installation. High-speed flywheels are more expensive than these.

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