How Air Brakes Work ?

air brake system has ability to do high Force braking with small input force it can be done because air brakes generating power from pressurized air to pull the brake shoe then how air brake can do that in this video we will learn how air brake system works air brakes is selected to replace hydraulic brake that have less braking force on heavyduty vehicle so air braake is one of brake control system or it is not the brake actuator system Sy it means air brake system is a mechanism to activate the brake actuator on its vehicle generally the actuators that are combined with air brake control system is drum brake system the example you can see this Chassy here we have a set of drum brake system at the tip of brake shoes there is a cam if we rotate this cam it will push both brake shoes to the outside so that the brake active and if we look more detail the cam is connected to a push rod so to activate the drum brakes we need to push this push rod this is the job of air BR system air brake will high forcely push the push rod so the result both brake shoes will be pressed to the drum with high force it will create a high Force breaking for more detail we start from the engine side here we can see an air compressor air compressor connected to the engine pulley via a fan belt so the compressor works once engine run it used to supply the air pressure to the air brake system then from the compressor there are three channels an inlet Channel and two output channels both output channels used to distribute pressurized air to the air tanks inside the air tanks the pressurized air is stored here the source of energy to operating the air BR but the air that are stored certainly have contaminant like dust and water we know that water is uncompressible material so that if this water come into the system it may break the air bre components to be done it before the air come into the tanks pressurized air will be flow to the air dryer this component will separate air from from all contaminants so that here the air is free from water and water will be thrown away from waste Channel and then we back to compressor the inlet hose has a connection to the valve mechanism it called Governor it functions to keep the pressure in working pressure and not over pressure the working pressure of air BR system approximately 100 to 150 psi so when the pressure inside the system over 150 psi the valve here will close and it will close the air path from outside but it will open the air path from the air dryer for more detail Governor have four channels an inlet Channel coming from outside an outlet Channel goes to compressor a channel to the air tank and another Channel coming from Air Dryer a channel from tank has a function to control the governor valve it located at the top inside of this room room there is a membrane which is if the pressure inside this room gets higher it will automatically close the inlet channel the maximum pressure is 150 psi so if it exceeds the pressure the membrane will move down it will move the Pistons that are connected with it the result Inlet channel is closed and the channel from Air Dryer is opened in this position air compressor still operating but the air that are compressed is only circulating inside the system so that it will not increase the pressure anymore when the pressure drops under 100 PSI this membrane back to move up so that it will slowly open the inlet Channel it will make compressor back to supply the air from outside to the tanks then we move to the cabin area here we can see a brake valve the valve is located under the brake pedal so when we press the brake pedal it will push the Piston inside of this valve so what next if we see the operating inside of brake valve hear the mechanism there are two inlet hose from the tank and Outlet hose to the next Parts when the pedal is not step on the Piston surface will close all Inlet channels when we step on the pedal piston pushed down and it will open the outlet channel the interesting thing the Piston position influences the flow of air to the outlet channel so when we hold the pedal on short range the channel will open in tiny Gap it will limit the flow but when we step on the pedal at full the channel will open in maximum Gap so the flow will be maximum this mechanism aims to make the brake has variable of power so that the driver can operate the brake according to the road conditions we go to the next part we go to relay valve it functions to cut the air path so the air arrived at the actuator faster because when the air has to flow to brake valve it may occur the delay of braking with this relay the air from the tank can be distribute directly to the actuator without flow to the brake valve then how it works when the Piston of brake valve is pressed the air flow from Outlet Channel brake valve to the signal Channel and relay valve this air flow will push the valve below of them the pushed valve will open the main channel that connect air tank and brake chamber brake chamber is a component to transform air pressure to the mechanical movement the air from relay valve will push the air chamber inside the brake chamber so it will expand the membrane this membrane connected to push rod so the expanded membrane will push the push rod but before reach the brake chamber the air from relay valve will flow through quick release valve this valve aims to distribute the air on two side of brake chamber another function is to release the brake faster so when the braking is finished the pressure at relay valve will drop it will close the main channel so the air pressure on brake chamber side is thrown away from bottom of relay valve but from brake chamber it needs more time to travel air so to make the release faster the air at the brake chamber will be thrown away from quick release valve this component Works automatically once the pressure is dropped so on air brake system the amount of air pressure is influencing the power of braking the pressure of this tank should reach 100 PSI at minimum before the vehicle operating that's why we always see the driver run the engine in approximately 30 minutes before they drive it aims to fulfill the pressure inside this tank to reach 100 PSI that's the animation of air BR system hope adds our insight

Channel: Amrie Muchta

Views: 124,338

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Id: twuO2tsuNKo

Length: 7min 30sec (450 seconds)

Published: Tue May 28 2024