Brake and Dynamometers

Brake and Dynamometers

Contents

Brake and Dynamometers 1

Define Brake and materials for brake lining 1

List and recall types of brake such as shoe brake, band brake, block brake, etc 2

Recall the Braking phenomena of a vehicle 3

Define and classify Dynamometer 4

List and recall types of Absorption dynamometers 5

Recall types of Transmission dynamometers 6

Define Brake and materials for brake lining

A brake is a mechanical device used to slow down or stop the motion of a moving object by converting the kinetic energy into heat energy. Brakes are commonly used in vehicles, machines, and industrial equipment to ensure safe and controlled operation.

The two most common types of brakes are friction brakes and hydraulic brakes. Friction brakes, also known as mechanical brakes, use the force of friction to slow down or stop the motion of an object. Hydraulic brakes, on the other hand, use hydraulic pressure to exert force on the brake pads or shoes.

Brake lining is the material used in friction brakes to create the necessary frictional force to slow down or stop the motion of an object. The brake lining is typically made of materials that have high friction coefficients, good heat resistance, and wear resistance. Common materials used for brake lining include:

  1. Organic materials: Organic brake linings are made from a mixture of fibers, resins, and fillers, such as rubber, carbon, and Kevlar. Organic materials provide good braking performance, low noise, and good pedal feel. However, they have relatively low heat resistance and can wear out quickly.
  2. Metallic materials: Metallic brake linings are made from a mixture of metals, such as copper, steel, and iron, and are typically used in high-performance applications. Metallic materials have good heat resistance and wear resistance, but they can be noisy and generate a lot of dust.
  3. Ceramic materials: Ceramic brake linings are made from ceramic fibers, resins, and fillers, such as silica and alumina. Ceramic materials provide excellent heat resistance, wear resistance, and low dust generation. However, they can be expensive and have a lower friction coefficient compared to other materials.

The selection of brake lining materials depends on the application, operating conditions, and performance requirements. Proper selection of brake lining materials is critical to ensure safe and reliable operation, prevent premature wear, and maximize the service life of the brake system.

List and recall types of brake such as shoe brake, band brake, block brake, etc

Brakes are mechanical devices used to slow down or stop the motion of a moving object. There are various types of brakes used in different applications, depending on the requirements and operating conditions. Some of the common types of brakes are:

  1. Shoe brake: A shoe brake is a type of brake that uses a pair of brake shoes to press against the surface of a rotating drum or disk. The shoes are connected to a brake linkage, which applies force to the shoes when the brake is applied, creating friction and slowing down or stopping the rotation of the drum or disk.
  2. Band brake: A band brake is a type of brake that uses a flexible band or strap to wrap around the circumference of a rotating drum or pulley. The band is tightened by a brake lever or linkage, creating friction and slowing down or stopping the rotation of the drum or pulley.
  3. Block brake: A block brake is a type of brake that uses a block or pad to press against a stationary surface, such as a rail or a floor. The block is connected to a brake linkage, which applies force to the block when the brake is applied, creating friction and stopping the motion of the object.
  4. Disk brake: A disk brake is a type of brake that uses a pair of brake pads to press against the surface of a rotating disk. The brake pads are connected to a calliper, which applies force to the pads when the brake is applied, creating friction and slowing down or stopping the rotation of the disk.
  5. Drum brake: A drum brake is a type of brake that uses a pair of brake shoes to press against the surface of a rotating drum. The shoes are connected to a brake linkage, which applies force to the shoes when the brake is applied, creating friction and slowing down or stopping the rotation of the drum.
  6. Hydraulic brake: A hydraulic brake is a type of brake that uses hydraulic pressure to apply force to the brake pads or shoes. The brake fluid is pressurised by a master cylinder, which activates the brake calliper or brake drum, creating friction and slowing down or stopping the motion of the object.

These are just a few of the common types of brakes used in various applications. The selection of brake type depends on the specific application, operating conditions, and performance requirements. Proper selection of the brake type is critical to ensure safe and reliable operation, prevent premature wear, and maximise the service life of the brake system.

Recall the Braking phenomena of a vehicle

Braking is a critical function of any vehicle, as it helps to slow down or stop the motion of the vehicle and prevent accidents. When a vehicle brakes, a complex set of physical phenomena takes place, including the following:

  1. Friction: The most important phenomenon that takes place during braking is friction. Friction is the force that resists motion between two surfaces in contact with each other. When a vehicle brakes, the brake pads or shoes press against the rotating wheels or drums, creating friction that slows down or stops the rotation of the wheels. The amount of friction generated depends on various factors, such as the type of brake system, the material of the brake pads or shoes, and the condition of the road surface.
  2. Heat generation: During braking, a significant amount of heat is generated due to friction between the brake pads or shoes and the rotating wheels or drums. This heat can cause the brake system to overheat, leading to reduced braking performance or even brake failure. To prevent this, brake systems are designed to dissipate heat through various means, such as ventilation, cooling fins, or heat sinks.
  3. Brake fade: Brake fade is a phenomenon that occurs when the braking performance of the vehicle reduces due to excessive heat generated during braking. This can be caused by various factors, such as prolonged or repeated braking, overloading of the vehicle, or poor quality brake components. Brake fade can significantly increase the stopping distance of the vehicle and can cause accidents.
  4. Anti-lock braking system (ABS): Modern vehicles are equipped with an anti-lock braking system (ABS), which helps to prevent the wheels from locking up during braking. ABS works by modulating the brake pressure on each wheel, allowing the wheels to rotate freely and maintain traction with the road surface. This helps to reduce the stopping distance of the vehicle and improve overall braking performance.
  5. Regenerative braking: Some hybrid or electric vehicles use regenerative braking, which converts the kinetic energy of the moving vehicle into electrical energy that can be stored in the battery. This helps to improve the fuel efficiency of the vehicle and reduce emissions.

These are some of the important braking phenomena that occur in a vehicle during braking. Understanding these phenomena is critical to ensuring safe and reliable operation of the vehicle, and to selecting and maintaining the appropriate brake system for the specific application.

Define and classify Dynamometer

A dynamometer is a device used to measure and record the power and torque output of an engine or motor. It is commonly used in the automotive and aerospace industries, as well as in research and development laboratories, to evaluate the performance of engines, motors, and other power sources. Dynamometers are typically classified based on their design and the type of power they can measure.

  1. Absorption dynamometer: An absorption dynamometer is a device that absorbs the power output of an engine or motor and converts it into heat or mechanical energy that is dissipated to the environment. This type of dynamometer is commonly used for testing engines and motors in a controlled environment.
  2. Transmission dynamometer: A transmission dynamometer is a device that measures the torque and power output of an engine or motor by placing it in line with a transmission system. This type of dynamometer is commonly used for testing large engines and motors, such as those used in heavy equipment and industrial applications.
  3. Hydraulic dynamometer: A hydraulic dynamometer is a device that uses a hydraulic system to measure the torque and power output of an engine or motor. This type of dynamometer is commonly used in research and development applications where precise measurement and control of power output are required.
  4. Electric dynamometer: An electric dynamometer is a device that uses an electric motor to measure the torque and power output of an engine or motor. This type of dynamometer is commonly used in automotive and aerospace testing, as well as in research and development applications.
  5. Eddy current dynamometer: An eddy current dynamometer is a device that uses electromagnetic induction to measure the torque and power output of an engine or motor. This type of dynamometer is commonly used for testing small engines and motors, such as those used in motorcycles and boats.

In summary, dynamometers are devices used to measure and record the power and torque output of an engine or motor. They are classified based on their design and the type of power they can measure, including absorption, transmission, hydraulic, electric, and eddy current dynamometers.

List and recall types of Absorption dynamometers

An absorption dynamometer is a device that absorbs the power output of an engine or motor and converts it into heat or mechanical energy that is dissipated to the environment. This type of dynamometer is commonly used for testing engines and motors in a controlled environment. There are various types of absorption dynamometers, including:

  1. Prony brake dynamometer: This is a simple absorption dynamometer that consists of a wooden block, which is tightened around the flywheel of an engine or motor by means of a rope or a belt. As the engine or motor rotates, the resistance applied by the wooden block generates a braking force that is proportional to the power output of the engine or motor. The brake force is measured using a spring balance, and the power output is calculated using the formula P = F x dN/dt, where P is the power output, F is the brake force, and dN/dt is the angular velocity of the engine or motor.
  2. Rope brake dynamometer: This is a type of dynamometer that uses a rope wound around a drum to absorb the power output of an engine or motor. The rope is attached to a lever arm that is used to measure the brake force. The power output is calculated using the same formula as for the Prony brake dynamometer.
  3. Hydraulic dynamometer: A hydraulic dynamometer is a type of absorption dynamometer that uses a fluid to absorb the power output of an engine or motor. The fluid is forced through a hydraulic turbine or a piston, and the resistance generated by the fluid is proportional to the power output of the engine or motor. The power output is calculated using the formula P = T x w, where P is the power output, T is the torque, and w is the angular velocity of the engine or motor.
  4. Eddy current dynamometer: An eddy current dynamometer is a type of absorption dynamometer that uses electromagnetic induction to generate a braking force. The braking force is proportional to the power output of the engine or motor, and is generated by the interaction of a magnetic field and the electrical current induced in a conductive disc. The power output is calculated using the formula P = T x w, where P is the power output, T is the torque, and w is the angular velocity of the engine or motor.

In summary, the main types of absorption dynamometers include Prony brake, rope brake, hydraulic, and eddy current dynamometers. These devices are commonly used in automotive, aerospace, and research and development applications to measure and evaluate the performance of engines and motors.

Recall types of Transmission dynamometers

Transmission dynamometers are used to measure the power output and torque of a vehicle’s transmission system. This type of dynamometer is typically used in automotive engineering to test and evaluate the performance of transmission systems.

There are several types of transmission dynamometers, including:

  1. Epicyclic Gearbox Dynamometer: This type of transmission dynamometer uses a planetary gearbox, which consists of a sun gear, planet gears, and a ring gear. The gearbox is connected to the transmission being tested, and the torque is measured by the reaction force applied to the sun gear. The power output is then calculated based on the rotational speed and torque.
  2. Hydraulic Dynamometer: A hydraulic dynamometer uses a fluid coupling to measure the power output and torque of a transmission system. The fluid coupling is connected to the transmission being tested, and the torque is measured by the resistance of the fluid. The power output is then calculated based on the fluid flow rate and the pressure drop across the coupling.
  3. Electric Dynamometer: An electric dynamometer uses an electric motor to simulate the load of the transmission system being tested. The electric motor is connected to the transmission and the torque is measured based on the electrical power consumption of the motor. The power output is then calculated based on the motor speed and the measured torque.
  4. Eddy Current Dynamometer: An eddy current dynamometer can also be used to measure the power output and torque of a transmission system. It uses a magnetic field and a conductive disc to create an eddy current, which generates a braking force. The braking force is proportional to the torque of the transmission system being tested, and the power output is then calculated based on the rotational speed and the measured torque.

In summary, the main types of transmission dynamometers include epicyclic gearbox, hydraulic, electric, and eddy current dynamometers. These devices are commonly used in automotive engineering to test and evaluate the performance of transmission systems in various types of vehicles.