Hydraulic braking system Working | Parts | Diagram

In this article, we will learn about what is hydraulic braking systems.It’s working principles, advantages, and applications. We have also included diagrams and pictures to make it easier for you to understands.

what is hydraulic braking system ?

A hydraulic braking system is a mechanism that uses brake fluid to transfer pressure from the brake pedal to the brakes, enabling effective slowing down or stopping of a vehicle.

Must Read : Air Brake System

history

The hydraulic braking system has a rich history that dates back to the 19th century. Early innovations in horse-drawn carriages led to the recognition of the need for improved braking solutions. The development gained momentum with the introduction of the air brake system for railways in 1869. In the early 1900s, hydraulic braking systems started to gain popularity in automobiles, utilizing a master cylinder and hydraulic lines. The introduction of disc brakes in the 1950s revolutionized braking performance, and the advent of Anti-Lock Braking Systems (ABS) in the 1970s further improved safety. Today, hydraulic braking systems continue to evolve with advanced technologies, providing precise control and enhancing overall driving experience.

Hydraulic system working principle

Hydraulic systems operate based on Pascal’s law, which states that when pressure is applied to a fluid in a confined space, it is transmitted equally in all directions.

Pascal’s Law : Pascal’s law states that when pressure is applied to a confined fluid, it is transmitted equally in all directions. This means that any change in pressure within a closed system is distributed uniformly throughout the fluid. The principle forms the basis of hydraulic systems, where fluid pressure is used to transmit force and control mechanical operations.

construction of hydraulic braking system

The construction of hydraulic braking systems involves assembling various parts. These include the brake pedal, also called a lever, an actuating rod known as a wreath, and a master cylinder assembly containing one or two pistons, a return spring, gaskets or O rings, and a fluid reservoir.

Reinforced hydraulic lines are used, and the brake caliper assembly consists of one or two hollow pistons made of aluminum or chrome-plated steel, known as caliper pistons.

A thermally conductive brake system consists of pads and either rotors (brake discs) or drums attached to an axle. The system is filled with glycol-ether-based brake fluid to exert force on all four wheels, although other fluids may be used.

Traditionally, passenger vehicles had drum brakes on all four wheels. Disc brakes were typically used in the front, while drum brakes were employed in the rear. Disc brakes offer better heat dissipation, resistance to fading, and enhanced safety compared to drum brakes. This has led to a significant increase in the use of four-wheel disc brakes. Hydraulic brake pedals provide quicker and more consistent pad return upon release.

parts of hydraulic braking system

The hydraulic braking system is comprised of several key components that work together to facilitate effective braking. Let’s explore these parts:

Brake Pedal: The brake pedal, typically a lever, is the foot-activated component that allows the driver to apply the brakes.
Master Cylinder: The master cylinder is a crucial part responsible for converting the force exerted on the brake pedal into hydraulic pressure. It consists of one or two pistons, a return spring, gaskets or O rings, and a fluid reservoir.
Hydraulic Lines: Reinforced hydraulic lines, often made of flexible metal or durable rubber, carry the pressurized brake fluid from the master cylinder to the brake calipers or wheel cylinders.
Brake Calipers or Wheel Cylinders: Brake calipers, found in disc brake systems, or wheel cylinders, present in drum brake systems, are responsible for applying friction to the brake pads or shoes. In disc brakes, calipers house pistons that push the brake pads against the rotor, while in drum brakes, wheel cylinders expand to force the brake shoes against the drum.
Brake Pads or Shoes: Brake pads, utilized in disc brake systems, or brake shoes, employed in drum brake systems, are designed to create friction when pressed against the brake rotor or drum. This friction generates the necessary braking force to slow down or halt the vehicle.
Brake Rotors or Drums: In disc brake systems, the brake rotor is a flat, disc-shaped component that rotates with the wheel. When the brake pads clamp down on the rotor, it produces the required friction to slow down the vehicle. In drum brake systems, the brake drum is a hollow, cylindrical component attached to the wheel. As the brake shoes are forced against the drum, it generates the braking force.
Brake Fluid: Brake fluid, often glycol-ether-based, serves as the specialized hydraulic fluid that transmits the pressure from the master cylinder to the brake calipers or wheel cylinders. It plays a vital role in ensuring the proper functioning of the hydraulic system.

These components collectively enable the hydraulic braking system to deliver reliable and responsive braking performance, ensuring safety on the roads.

how does a hydraulic system works ?

The hydraulic braking system is comprised of several key components that work together to facilitate effective braking. Let’s explore these parts:

Brake Pedal: The brake pedal, typically a lever, is the foot-activated component that allows the driver to apply the brakes.
Master Cylinder: The master cylinder is a crucial part responsible for converting the force exerted on the brake pedal into hydraulic pressure. It consists of one or two pistons, a return spring, gaskets or O rings, and a fluid reservoir.
Hydraulic Lines: Reinforced hydraulic lines, often made of flexible metal or durable rubber, carry the pressurized brake fluid from the master cylinder to the brake calipers or wheel cylinders.
Brake Calipers or Wheel Cylinders: Brake calipers, found in disc brake systems, or wheel cylinders, present in drum brake systems, are responsible for applying friction to the brake pads or shoes. In disc brakes, calipers house pistons that push the brake pads against the rotor, while in drum brakes, wheel cylinders expand to force the brake shoes against the drum.
Brake Pads or Shoes: Brake pads, utilized in disc brake systems, or brake shoes, employed in drum brake systems, are designed to create friction when pressed against the brake rotor or drum. This friction generates the necessary braking force to slow down or halt the vehicle.
Brake Rotors or Drums: In disc brake systems, the brake rotor is a flat, disc-shaped component that rotates with the wheel. When the brake pads clamp down on the rotor, it produces the required friction to slow down the vehicle. In drum brake systems, the brake drum is a hollow, cylindrical component attached to the wheel. As the brake shoes are forced against the drum, it generates the braking force.
Brake Fluid: Brake fluid, often glycol-ether-based, serves as the specialized hydraulic fluid that transmits the pressure from the master cylinder to the brake calipers or wheel cylinders. It plays a vital role in ensuring the proper functioning of the hydraulic system.

These components enable the hydraulic braking system to deliver reliable and responsive braking performance, ensuring safety on the roads.

working of hydraulic braking system

# Drum Hydraulic Brake

These following process happens when the driver applies a brake in a vehicle which is equipped with hydraulic brakes mounted on the drum. The speed or activation of the brake pedal causes a master cylinder to move a rod connected between the pedal and the piston, which in turn pushes the piston of the master cylinder inside the master cylinder same like a medical syringe.

When the pistons inside the master cylinders move, they compress the brake fluid, converting mechanical energy into hydraulic pressure. This highly compressed brake fluid then flows into the brake system, transferring the hydraulic pressure from the master cylinder to the brake drum.

When the high-pressure brake fluid enters the wheel or drum cylinder, it causes the piston inside the cylinder to move. This movement then expands the brake shoe that is attached to it.

As the brake shoe expands, it creates friction against the drum lining (the rotating part of the drum). This friction converts the vehicle’s kinetic energy into heat energy, ultimately bringing the vehicle to a stop.

Single-acting drum-type braking: This type of braking system applies braking force to a single wheel or a pair of wheels. It works the same way as explained earlier.

Double-acting drum-type braking: In this system, high-pressure brake fluid from the master cylinder is divided into two directions. It provides braking force to all wheels of bikes or cars. This is achieved by using tandem master cylinders.

#2. Disc hydraulic brake

The process of braking in a vehicle with a disc-type hydraulic brake is similar to that of a drum brake. When the driver applies the brakes, the high-pressure brake fluid enters the brake lines. However, in a disc brake system, the high-pressure brake fluid enters the disc caliper cylinder instead of the drum.

This high-pressure brake fluid causes the caliper piston to move, which in turn speeds up the brake pads attached to the piston inside the caliper. The brake pads clamp onto the rotating disc rotor, creating friction. This friction converts the kinetic energy of the vehicles into heat energy, ultimately stopping or decelerating the vehicle.

Single Acting Disc Type Braking – Single acting disc type hydraulic brakes work in the same way as described above. They provide braking force to a single wheel or a pair of wheels.

Double-acting Disc Type Braking – In double-acting disc type hydraulic brakes, high-pressure brake fluid is sent in two directions from the master cylinder. This setup is used in both wheels of bikes and all wheels of cars, thanks to the tandem master cylinders

specifications

When selecting a hydraulic brake, it is important to consider the following performance specifications:

Torque Rating: The brake should have a torque rating that meets or exceeds the requirements of the application it is used for. This ensures that it can provide enough force to stop the movement effectively.
Power: Hydraulic brakes have a maximum power rating, which indicates their ability to handle high power requirements. It determines the brake’s capacity to stop the motion efficiently.
Speed: This specification is relevant only for rotary brakes and indicates the maximum speed at which the brake can operate effectively. It ensures that the brake can handle the rotational speed without compromising its performance.
Maximum Pressure: Hydraulic brakes have a maximum pressure rating that indicates the highest pressure they can handle. It is important to ensure that the brake can withstand the required pressure for optimal braking performance.
Shaft Configuration: The brake’s shaft configuration refers to how it is mounted in relation to the application. It can be in-line, parallel, or at an angle, depending on the specific requirements of the system.

applications of hydraulic braking system

Hydraulic braking systems have a wide range of applications across various industries. Let’s explore some of the key areas where hydraulic braking systems are commonly utilised:

Automotive Industry: Cars, trucks, and motorcycles use hydraulic brakes for reliable braking.
Commercial Vehicles: Buses, trucks, and trailers rely on hydraulic brakes for safe transportation.
Aircraft: Hydraulic brakes ensure safe landings and ground handling.
Railway Systems: Trains use hydraulic brakes for controlled deceleration and synchronized braking.
Industrial Machinery: Cranes, forklifts, and construction equipment employ hydraulic brakes for safe operation.
Marine Industry: Ships and boats use hydraulic brakes for docking and maneuvering.
Amusement Rides: Hydraulic brakes provide controlled and safe braking for rides and roller coasters.
Off-Road Vehicles: ATVs and off-road trucks rely on hydraulic brakes for effective braking in challenging terrains.
Industrial Manufacturing: Conveyor systems and presses utilize hydraulic brakes for controlled deceleration.

Advantages of hydraulic braking system

Hydraulic braking systems offer several advantages over other types of braking systems. Let’s explore some of the key benefits:

Enhanced Safety: Hydraulic braking systems provide quick and precise braking, contributing to overall vehicle safety. They allow for shorter stopping distances, enabling drivers to react swiftly to unexpected obstacles on the road and reducing the risk of accidents.
Improved Control: Hydraulic braking systems offer excellent control and modulation of brake force. The hydraulic pressure can be finely adjusted, allowing for smooth and gradual braking. This enhances overall control during maneuvers, cornering, and challenging road conditions.
Consistent Performance: Hydraulic braking systems are designed to dissipate heat efficiently, preventing brake fade even during prolonged heavy use. This ensures consistent and reliable braking performance, maintaining effectiveness over extended periods.
Durability and Longevity: Hydraulic brakes are known for their durability and longevity. The hydraulic components, such as master cylinders and wheel cylinders, are built to withstand high pressures and provide reliable performance for extended periods. Proper maintenance ensures their continued functionality.
Versatility and Adaptability: Hydraulic braking systems are versatile and can be adapted to various vehicle types and sizes. They can be customized to meet specific requirements, accommodating different applications, from compact cars to heavy-duty trucks. This adaptability makes hydraulic brakes a suitable choice for a wide range of vehicles.
Efficient Heat Dissipation: Hydraulic braking systems have effective heat dissipation mechanisms, preventing overheating of the braking components. This helps to maintain the integrity of the brake system and ensures consistent performance even during demanding driving conditions.
Compatibility with Anti-Lock Braking Systems (ABS): Hydraulic braking systems are compatible with Anti-Lock Braking Systems (ABS). ABS technology prevents wheel lock-up during sudden braking, enabling the driver to maintain control and steer the vehicle. The hydraulic system’s responsiveness and modularity make it ideal for integration with ABS.
Ease of Maintenance: Hydraulic braking systems are relatively easy to maintain. Regular checks and inspections of brake fluid levels, hydraulic lines, and components ensure optimal performance. Routine maintenance and timely replacement of worn-out parts contribute to the longevity and efficiency of the braking system.
Established Technology: Hydraulic braking systems have a long history of development and refinement. They are a well-established technology with widespread usage and support. This means that parts and expertise are readily available, simplifying maintenance and repairs.

disadvantages of hydraulic braking system

Complexity: Hydraulic systems are complex, requiring specialized knowledge for installation and maintenance.
Potential Leakage: There is a risk of fluid leakage, which can affect braking performance and require immediate attention.
Fluid Contamination: Brake fluid can become contaminated over time, leading to degraded system performance and potential component damage.
Compliance Requirements: Hydraulic braking systems must comply with industry regulations and undergo periodic inspections.
Cost: Hydraulic systems, particularly those with advanced features, can be more expensive to manufacture, install, and maintain.
Response Time: There may be a slight delay in initial braking response due to the time required for hydraulic pressure buildup.
Sensitivity to Temperature: Extreme temperatures can impact system performance, with cold temperatures thickening the fluid and hot temperatures reducing brake efficiency

Source : Wikipedia