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 parts, diagram, functions, and how it works. Well, also look at the symptoms of a bad flywheel, its causes and its replacement costs
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. Changing the stored energy on the flywheel requires its rotational speed to increase or decrease. 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
Related: What Is A Transmission System? Its Diagram, Parts, and Types
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 centre of the crankshaft, vibrations 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 stabilising 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:
Main Body 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 maximises 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 aluminium. 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 disc 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.
Symptoms of a Bad Flywheel
The symptoms of a bad flywheel include slipping gears, difficulty in changing gears, burning smell, vibrating clutch pedal, clutch drag, and difficulty starting the gear.
Slipping gears
There are a number of potential causes of gear slippage, but one of the most common is a faulty flywheel. When the flywheel is malfunctioning, it is unable to produce the required torque to prevent the gears from slipping.
Wear and tear, damage, or even a flaw in the flywheel itself are some of the potential causes of this.
Difficulty changing gears
Gear-shifting issues may be caused by a damaged flywheel. The gears may shift irregularly if the flywheel isn’t functioning correctly. There are a number of possible causes for why shifting gears could be challenging with a damaged flywheel.
One explanation is that the flywheel does not exert enough force on the gears, which makes it difficult for them to mesh.
Burning smell
An indication that your clutch isn’t operating properly or isn’t being used appropriately is a burning smell coming from underneath your car. It results from clutch plate wear and tear, which may be brought on by a deformed flywheel that generates excessive heat and friction.
If you don’t swap out your flywheel, the clutch will probably stop functioning.
Vibrating clutch pedal
There can be an issue with the flywheel if your clutch pedal is vibrating. There are a number of plausible explanations for why a faulty flywheel generates a vibrating clutch pedal.
One possibility is that the engine vibrations brought on by the bent flywheel are causing the clutch pedal to vibrate.
Clutch drag
The clutch may drag if there is too much inertia in the flywheel. The flywheel tries to continue spinning at its pre-acceleration speed as the engine and vehicle accelerate.
The entire system will drag if the clutch tries to seize the flywheel too rapidly and it resists.
Difficulty in starting a car
Because it might stop the engine from turning over, a damaged flywheel can contribute to starting issues. This frequently results from a seized flywheel, which won’t turn even when the engine is started.
The starting motor may experience issues as well.
Engine stalls
A rotating part of the engine called the flywheel stores energy and aids in a smooth start-up. The engine may stall and idle unevenly as a result of a damaged flywheel. This is due to the faulty flywheel’s inability to retain sufficient energy or to enable a smooth startup.
Causes of a Faulty Flywheel
The reasons why your car’s flywheel goes bad include overheating, inadequate maintenance, and poor driving practices.
Overheating: Your flywheel may crack or deform due to excessive heat generated by a faulty or slipping clutch.
Inadequate maintenance: Ignoring clutch problems, no matter how little, may lead to flywheel damage, which is much more expensive to replace. Make sure all components are balanced and that new clutches and starters are torqued according to the recommended specifications.
Poor driving practices: Poor driving practices that might harm the flywheel include riding the clutch, towing weights that are too heavy for your car, driving in the wrong gear, and putting your car in reverse or first gear when the engine is off.
Can you drive with a Bad flywheel?
Although it is technically feasible to drive with a damaged flywheel, we don’t advise it. Any flaws can have a big knock-on effect elsewhere, especially within the clutch components, the crankshaft, and the engine, thanks to the crucial role that your flywheel plays in ensuring a smooth transfer of power from your engine to your wheels.
Flywheel Replacement Costs
Depending on the car’s make and model, the kind of flywheel (single-mass or dual-mass), and local labour costs, the cost of replacing a flywheel can vary significantly.
The flywheel component itself will typically cost between $400 and $800. Depending on the complexity of the task and the service centre’s hourly rates, labour expenses for replacing a flywheel usually range from $400 to $800 or more.
The entire cost of replacing the flywheel might be anything from $800 to $1,600 or more. For a more precise quote depending on your particular car and location, it is important that you speak with a nearby technician or service facility.
Furthermore, if additional parts, like the clutch assembly, need to be replaced concurrently, which can skyrock the price.