Flywheel

Flywheel: In This Article, I am going to discuss What is the Flywheel on Engine ? It’s Moment of Inertia, Function, Applications, Advantages and Disadvantages including images for better understandings.

what is the flywheel ?

A Flywheel is a Mechanical Device Which is connected to a rotating shaft, serving to regulate and stabilise the transmission of power from a motor to a machine. Its primary function is to ensure a consistent and smooth delivery of power throughout the operation.

A flywheel which is used in machines serves as a reservoir which stores energy during the period when the supply of energy is more than the requirement and releases it during the period when the requirement of energy is more than supply.

Must Read : Difference Between 2 stroke and 4 stroke engine

working principle of flywheel

Flywheel work based on the principle of conservation of energy. They store energy in the form of rotational motion by virtue of their high moment of inertia. This stored energy can be released and utilised when needed, allowing for efficient energy management in various applications.

It serves as an energy reservoir for vehicles, akin to a mechanical battery that stores energy in a chemical form. In the case of the flywheels, energy is stored as kinetic energy.

The rotational speed of the flywheel increases proportionally with the amount of energy generated. It possesses a substantial moment of inertia, indicating its weightiness. Rather than increasing its mass, it is more advantageous for the fly-wheel to spin at a higher velocity. This is because a lighter wheel generates twice as much energy as a flywheel that is either twice as heavy or heavier.

In other words, the lighter the flywheel, the greater the amount of stored energy. It is preferable to employ lightweight, high-speed fly-wheels instead of those with significant mass. However, heavier vehicles such as trailers, trucks, and vans necessitate it with more weight. These vehicles carry additional loads and do not require high speeds for their functioning.

Consequently, understanding the functioning of a flywheels reveals that higher speeds correspond to increased energy. Nonetheless, if the speed continues to rise unabated, the wheel may surpass its material strength, leading to its failure or breakage.

flywheel functions

The flywheel performs several important functions in mechanical systems:

1. Energy Storage: The primary function of a flywheel is to store excess energy during periods when the energy supply is greater than the demand. This stored energy is available for use when the demand exceeds the supply, helping to maintain a steady and consistent output.
2. Energy Regulation: It help regulate the energy flow within a system by smoothing out variations in power delivery. They absorb and store surplus energy during high-energy periods and release it during low-energy periods, ensuring a more stable and balanced energy supply.
3. Load Balancing: It assist in balancing the load and reducing fluctuations in rotational speed. They act as a rotational inertia reservoir, providing additional power during sudden increases in demand and compensating for temporary drops in power supply, thereby maintaining a more constant speed and reducing strain on the system.
4. Power Backup: It can serve as a short-term power backup in case of power outages or interruptions. They store energy during normal operation and can quickly release it when needed, providing temporary power to critical systems until a more permanent backup power source comes online.
5. Mechanical Momentum: It provide rotational momentum to support the smooth operation of mechanical systems. They stabilise and maintain the momentum of rotating components, reducing vibrations, and ensuring consistent performance.

Overall, It’s function is to store, regulate, and release energy in order to enhance the efficiency, stability, and reliability of mechanical systems across various applications.

parts of flywheel

1. flywheel housing

The flywheel housing remains solid and is positioned outside of the flywheel. The fly-wheels itself is the engine component responsible for rotation, delivering power to the alternator

2. Springs

It consists of two parallel sets of curved springs. These springs are designed with an adjustable outer arc, allowing them to elevate during engine operation. The soft outer arc springs primarily enhance the range of uncertain resonance frequencies

3. Planetary Wheel

The planetary wheel is formed by several planetary gears fixed onto a flywheel bracket. When the fly-wheel bracket rotates through the operation of a screw, the engagement with the outer ring gear produces a compound motion involving both revolution and rotation of each planetary gear.

4. Axial and Radial Sliding Bearing

The axial sliding bearing serves the purpose of weight compensation, while the radial bearings are employed to counterbalance any imbalances or parasitic radial forces caused by the motor or generator unit.

5. ring gear

A ring gear is attached to the outer diameter of the flywheel. It is typically securely fastened to the flywheel using an interference fit, achieved by heating the ring gear. This thermal expansion enables the placement of the ring gear around it.

6. support disc

It incorporates an internal support disc that ensures structural integrity by providing support to the two-phase bent springs and other vital components.

7. Flywheel Sliding Shoe

The sliding shoes are designed with a convex radial outer portion that rests against the inner wall of the flywheel. Carefully engineered to promote controlled slip and minimize wear and tear.

8. flywheel cover

To safeguard the internal mechanisms of the flywheel and maintain its optimal performance, a commonly used cover is made of chrome. The chrome-plated fly-wheel cover effectively prevents dust from interfering with the internal functions, ensuring smooth operation.

Types of Flywheel

a. Solid disk flywheel

A solid disk flywheel is a circular disk commonly used in cast iron single fly-wheel thresher systems. Leading manufacturers in India employ precise technologies to determine the size and dimensions of these fly-wheels, ensuring their desired performance. Various important factors are considered during the design process.

Solid disk flywheels experience two types of stresses: radial stress and tangential stress. These versatile tools typically consist of a disk and a hub section. To assess the suitability of a solid disk fly-wheel, its “mass moment of inertia” needs to be calculated, which involves determining the disk mass and outer radius. The density of the flywheel material is also taken into account.

b. Rimmed Flywheel

A rimmed flywheel consists of an inner hub, outer ring (known as the ‘rim’), and arms. Typically, rimmed flywheels have 4-6 arms. The rim experiences centrifugal force, resulting in tensile stress. Rim’s moment of inertia and mass moment of inertia are significant parameters.

Compared to solid disk flywheels, rimmed fly-wheels detonate at lower rotational speeds (assuming similar diameter and weight). Leading Indian fly-wheel manufacturers prioritise lightweight rimmed fly-wheels with high energy-carrying capacity. Increasing the center’s thickness enhances mechanical strength.

It can be categorised based on angular velocity (or rakish velocity) as follows:

c. high velocity

High-velocity flywheels typically operate between 30,000 and 60,000 revolutions per minute (rpm), with the possibility of further velocity enhancements. Their lightweight and user-friendly design contribute to their popularity, despite the higher cost compared to low-velocity flywheels.

To enhance user convenience, leading flywheel manufacturers in India employ robust magnetic levitation bearings in their high-velocity fly-wheels. These bearings offer exceptional durability and require minimal upkeep. Additionally, manufacturers can customise the capacity, size, and other characteristics of these fly-wheels to meet specific buyer requirements.

d. low velocity

Low-velocity flywheels, as the name suggests, have a significantly lower angular velocity compared to their high-velocity counterparts, typically reaching a maximum speed of 10,000 rpm. Although they are relatively cost-effective, their large size poses a challenge. Reputable suppliers assist clients in proper setup for optimal performance.

Unlike high-velocity fly-wheels, low-velocity flyw-heels lack convenient levitation directional features and require intermittent support. However, when correctly installed with additional structural support, low-velocity fly-wheels offer efficient and economical performance. It is important for buyers to regularly inspect the various components of these fly-wheels.

Leading flywheel manufacturers in India, such as Crescent Foundry, offer both single-mass and dual-mass fly-wheels in their product lineup. Now, let’s explore the key differences between these two types.

e. single mass flywheel

Single mass flywheels are crafted from a single piece of cast material, devoid of any movable components. They enable rapid engine revving and maintain a stable connection between the engine and clutch assembly. The notable benefits include increased warp and thermal resistance, enabling them to withstand abrupt gear and engine speed changes.

Durability stands as a paramount characteristic across flywheel variants. Single mass fly-wheels are resurfaced as needed, elevating their overall dependability and lifespan. Moreover, they offer a relatively lower cost. However, the usage of these fly-wheels can result in excessive vibration and noise, posing potential challenges.

f. dual mass flywhhel

In a dual-mass flywheel, there are two distinct fly-wheels: one connected to the clutch and the other to the crankshaft. These fly-wheels have high weight capacities (up to 50 kg) and monthly production capabilities. Diesel vehicles, especially larger ones with manual transmissions, commonly use dual-mass flywheels (some petrol vehicles also use them). The robust springs within the fly-wheels minimize torsional spikes and protect the gearbox.

Dual-mass flywheels are designed to reduce noise and vibrations during operation by incorporating advanced energy storage and transmission capabilities to the crankshaft. This results in smoother rotations between piston pulses. These fly-wheels optimise engine power utilisation, leading to enhanced fuel efficiency. It’s important to note that dual-mass fly-wheels cannot be resurfaced.

The global flywheel industry is projected to reach nearly $242 million by the end of 2027. The Indian fly-wheel sector is also experiencing significant growth, with top manufacturers continuously upgrading their portfolios and customising products to ensure superior performance and durability. The demand for fly-wheels as energy storage systems is exponentially increasing, and buyers should choose the appropriate type based on their specific requirements.

bad flywheel symptoms

Here are some common symptoms that indicate potential issues with a flywheel:

1. Clutch Slippage: If the flywheel is worn out or damaged, it may cause the clutch to slip. This means that the clutch will have difficulty engaging properly, resulting in a loss of power transmission from the engine to the drivetrain.
2. Vibrations and Noise: A damaged flywheel can lead to excessive vibrations and noise during operation. You may feel strong vibrations through the clutch pedal or hear unusual grinding, rattling, or squealing sounds coming from the transmission area.
3. Difficulty Shifting Gears: A faulty fly-wheel can make it difficult to shift gears smoothly. You may experience resistance or grinding when trying to engage or disengage the clutch, making gear changes challenging or jerky.
4. Engine Dragging or Stalling: A damaged flywheel can cause the engine to drag or stall when idling or during gear changes. This occurs because the fly-wheel fails to provide the necessary rotational momentum to keep the engine running smoothly.
5. Unusual Smells: If the flywheels is overheating due to excessive friction or slippage, you may notice a burning smell coming from the engine compartment. This can indicate a serious problem with the fly-wheels or clutch system.
6. Increased Pedal Effort: A damaged flywheels can result in a heavier clutch pedal feel. You may need to apply more pressure to engage or disengage the clutch, which can cause discomfort or fatigue during driving.

It’s important to note that these symptoms can also be indicative of other issues in the clutch system or transmission. If you notice any of these symptoms, it is recommended to have your vehicle inspected by a qualified mechanic to accurately diagnose and address the problem.

application of flywheel

Based on the provided information, here are the applications of flywheels:

1. Reciprocating Engine Stabilization: Flywheels are used to smooth out fast angular velocity fluctuations in reciprocating engines, such as those found in vehicles. By storing and releasing energy, the fly-wheel helps maintain a continuous power output, compensating for the intermittent energy source provided by the firing pistons.
2. Friction Motors: It is employed in friction motors, which power devices like toy cars. The mass distribution of the fly-wheel, often concentrated towards the rim, increases rotational inertia for a given total mass, optimising the efficiency of the motor.
3. Power Hammers and Riveting Machines: These are utilised in power hammers and riveting machines to provide intermittent pulses of energy at high power levels. Energy is accumulated in the flywheel over time and then released rapidly when needed, enabling efficient and powerful operation.
4. Directional Control and Motion Stabilisation: It find application in gyroscopes used for instrumentation, stabilising ships, satellite stabilisation (reaction wheel), and maintaining the spin of toys (friction motor). They also contribute to stabilising magnetically-levitated objects, such as in spin-stabilised magnetic levitation systems.
5. Electric Compensator: It can function as electric compensators, such as synchronous compensators or synchronous condensers. They can produce or absorb reactive power, improving power factor and adjusting grid voltage. These are controlled to spin at the desired frequency, maintaining synchronisation with the power system.

These applications demonstrate the versatility of flywheels in providing continuous power output, storing and releasing energy, stabilising motion, and improving electrical power quality.

Advantages of Flywheel

It offer several advantages in various applications:

1. Energy Storage Efficiency: Flywheels have high energy storage efficiency, as they can rapidly absorb and release energy with minimal losses. This makes them valuable in systems that require quick bursts of energy or efficient energy storage.
2. Power Smoothing and Stabilisation: It can smooth out fluctuations in power supply and demand. They can absorb excess energy during periods of high supply and release it during peak demand, helping to stabilize electrical grids and improve overall system reliability.
3. Rapid Response Time: It has an exceptionally fast response time, enabling them to deliver power almost instantly when needed. They can provide immediate backup power in critical situations, such as power outages, ensuring uninterrupted operation of vital systems.
4. Long Cycle Life: It has a long cycle life compared to many other energy storage technologies. They can sustain a large number of charge and discharge cycles without significant degradation, making them durable and cost-effective over their lifespan.
5. High Power Density: These have a high power density, meaning they can store a significant amount of energy in a relatively compact and lightweight design. This makes them suitable for applications where space is limited, such as in vehicles or small-scale energy storage systems.
6. Environmental Friendliness: These are a clean and environmentally friendly energy storage solution since they do not produce emissions during operation. They can contribute to reducing greenhouse gas emissions when used in conjunction with renewable energy sources.
7. Maintenance and Safety: It is generally require minimal maintenance and have a low risk of hazardous events compared to some other energy storage technologies. They do not involve chemicals or toxic materials, reducing potential safety concerns.
8. Versatility: It can be customised and adapted for various applications, from transportation to grid stabilisation. They offer flexibility in energy management, allowing for diverse uses across different industries.

These advantages make it an attractive choice for energy storage, power management, and stabilisation in a wide range of applications, contributing to increased efficiency, reliability, and sustainability.

disadvantages of flywheel

While flywheels have numerous advantages, they also have some limitations or disadvantages:

1. Limited Energy Storage Duration: It is best suited for short-duration energy storage applications. They may not be as effective for long-term storage needs compared to other technologies, such as batteries.
2. High Cost: Developing and implementing flywheel systems can be costly, especially when compared to certain alternative energy storage solutions. The manufacturing and maintenance expenses associated with flywheels can be significant.
3. Weight and Size: It is typically require a certain amount of mass to store energy effectively. This can result in larger and heavier systems, making them less suitable for applications with limited space or weight constraints.
4. Mechanical Stress and Safety Concerns: The high rotational speeds and forces involved in flywheel operation can subject the system to significant mechanical stress. Ensuring the structural integrity of the fly-wheels and its surrounding components is crucial for safety, and failure or breakdown of the fly-wheels could pose risks.
5. Energy Losses: Despite their overall efficiency, flywheels systems still experience some energy losses due to friction and mechanical resistance. These losses can impact the overall system efficiency and reduce the amount of usable energy stored and released.
6. Temperature Sensitivity: It can be sensitive to temperature changes. Extreme temperatures can affect the performance and longevity of the flywheel system, requiring additional cooling or insulation measures.
7. Noise and Vibration: The high-speed rotation of fly-wheels can generate noise and vibration, which may require noise dampening or isolation measures in certain applications.

It is important to consider these disadvantages alongside the advantages of fly-wheels when evaluating their suitability for specific applications and energy storage requirements.

Source : wikipedia