2.2.1 - Mechanical

The steering mechanism in a vehicle allows the driver to change the direction of the vehicle. This is achieved by altering the angle of the front wheels, which in turn guides the vehicle's path on the road. Effective steering ensures that the vehicle responds predictably to the driver's movements, allowing for smooth handling and stability when navigating turns or sudden changes in direction.

There are two main types of steering mechanisms: manual steering and power steering. Manual steering requires the driver to exert physical effort directly on the steering wheel. This type is typically found in older or lighter vehicles, where less force is needed to turn the wheels. In contrast, power steering is equipped with a system that assists the driver by using hydraulic or electric power. This makes it easier to turn the steering wheel, especially at low speeds or during tight maneuvers. Electric power steering is becoming increasingly popular in modern vehicles due to its efficiency and adaptability.

Different types of steering gearboxes influence how a vehicle handles. Each design has unique features and applications:
1. Worm and Nut: Durable and commonly used in larger vehicles for reliability.
2. Worm and Sector: Offers reasonable precision, suitable for trucks.
3. Worm and Roller: Reduces friction for a better driving experience, found in many cars.
4. Recirculating Ball: Uses balls to reduce friction, desired in heavier vehicles for strength.
5. Rack and Pinion: Provides precise steering with linear motion, widely used in modern vehicles.
6. Cam and Lever: An old design, rarely used today due to inefficiency.

Wheel geometry is crucial for vehicle performance. It affects how the tires contact the road, increasing safety and efficiency. Key parameters include:
1. Camber: The tilt of the wheels affects how they wear and handle corners.
2. Caster: This angle helps maintain stability when driving straight.
3. Toe-in/Toe-out: These adjustments dictate how the front wheels align with each other, impacting tracking and wear.
4. Kingpin Inclination: This angle helps the wheels return to straight after a turn.
5. Ackermann Principle: This principle ensures that as a vehicle turns, the inside wheels turn more sharply than the outside wheels, preventing tire wear.

Braking systems play a vital role in vehicle safety. The primary principle behind braking is to convert the kinetic energy (energy of movement) of the vehicle into heat energy, which slows down or stops the vehicle. A good braking system allows for rapid deceleration, immobilizes the vehicle when parked, helps maintain a steady speed on downhill slopes, and contributes to overall stability while driving.

Braking systems come in several types, each suited for different applications:
1. Mechanical Brakes: Operate via cables or rods and are mostly found in older vehicles for emergency or parking.
2. Hydraulic Brakes: Utilize hydraulic fluid to transfer force, common in most modern cars, providing efficient stopping.
3. Pneumatic Brakes: Use compressed air for larger brake chambers, typically seen in trucks and buses.
4. Electric Brakes: Employ electric actuators, found in electric vehicles and luxury cars for rapid response.
5. Vacuum Assisted Brakes: Boost pedal force with engine vacuum, commonly used in many cars and trucks.

There are two main types of brake systems: drum brakes and disc brakes.
1. Drum Brakes: These brakes consist of brake shoes that expand outward against the interior of a spinning drum, creating friction and slowing down the vehicle. They are mostly used on the rear wheels of vehicles.
2. Disc Brakes: This system utilizes a rotating disc and brake pads. When the brakes are applied, the calipers squeeze the pads against the disc, generating friction. Disc brakes are favored for their superior heat dissipation and consistent performance, especially in demanding situations. They are commonly found on the front, and increasingly on rear wheels as well.

The Anti-lock Braking System (ABS) is an essential safety feature in many vehicles. Its primary function is to prevent the wheels from locking up during sudden or hard braking. Locking up can result in loss of steering control, potentially leading to accidents. ABS achieves this by using sensors that monitor wheel speed, an electronic control unit (ECU) that processes this data, and hydraulic modulators that adjust brake pressure dynamically to maintain wheel rotation and enhance control.

The parking brake, also known as the handbrake or emergency brake, is crucial for keeping a vehicle stationary when parked. It mechanically or electronically locks the rear wheels of the vehicle, ensuring it doesn't roll away. Traditional systems use cables, while newer models may employ electronic systems, allowing for easier engagement and disengagement.

The suspension system in a vehicle serves three primary objectives:
1. Ride Comfort: It absorbs shocks caused by bumps, potholes, and uneven road surfaces, ensuring a smooth ride.
2. Road Holding: The suspension helps keep the tires in contact with the road, which is critical for stability and safety during cornering and braking.
3. Load Carrying: It supports the weight of the vehicle and any additional loads, maintaining consistent performance regardless of the driving conditions.

Different types of springs and shock absorbers play essential roles in a vehicle's suspension.
1. Springs:
- Leaf Spring: Composed of layers of steel; commonly found in the rear of trucks and vans due to their robustness.
- Coil Spring: Helical shape; widely used in cars for their compactness and ability to handle various weights.
- Torsion Bar: A straight bar that twists under load; can be adjusted for stiffness based on needs.
- Air Spring: Made of rubber bellows filled with pressurized air; provides a smooth ride and adjustable support.
2. Shock Absorbers:
- Telescopic Hydraulic: The most common type, using oil to resist movement and provide damping.
- Gas-Charged: Uses pressurized gas to offer consistent behavior.
- Double-acting: Catches energy during both upward and downward movements, improving stability.

The types of suspension systems determine how the wheels behave and interact with the vehicle.
1. Dependent Suspension: A solid axle connects left and right wheels, making it commonly used in trucks and commercial vehicles for reliability.
2. Independent Suspension: Each wheel moves separately, greatly improving comfort and handling, and is prevalent in most modern cars.
3. Semi-Independent Suspension: Offers some coupling between the wheels but less than fully dependent designs, used in cost-effective vehicles. Various designs for the rear axle aim to optimize performance based on specific needs.

Modern vehicles often feature advanced suspension systems that enhance ride quality and handling.
1. Electronic Control Suspension: This system continuously monitors driving conditions and adjusts parameters like damping and stiffness in real time to ensure optimal comfort and stability.
2. Proactive Suspension System: Utilizing advanced sensors and cameras, this system can anticipate road conditions and adapt the wheel movements to minimize impacts from bumps and maintain balance during turns.