construction and working of a cone clutch | construction and working of a hydraulic clutch | types of clutches present in a transmission system

Cone clutch

In the cone clutch the contact surfaces of the driving and driven members are made as portions of cones. A typical cone clutch is show in the picture

01 - TYPES OF CLUTCHES USED IN TRANSMISSION SYSTEM - CONSTRUCTION AND WORKING OF CONE CLUTCH

The flywheel is attached to the crankshaft by bolts passing through the web of the flywheel and a flange integral with the crankshaft. This male member is which made in two parts. The cone part is bolted to the centre flange splined on the driven shaft. This allows the cone to be made of aluminium and the centre is made of steel. This makes the cone to be lighter and the centre to have the necessary strength. The composite male member is carried on the crankshaft spigot, with a bush provided between them. The male cone member is attached to the gear box input shaft. A spring presses the male cone into the female cone of the fly wheel. The spring reaction is taken through a ball thrust bearing onto the clutch cover plate. The clutch cover plate is bolted to the rim of the flywheel by means of a number of hexagon headed screws.

To disengage the clutch, the male cone is drawn back along the spigot against the pressure of the spring. The faces of the cones are then separated. Now the engine flywheel no longer drives the male cone, and hence the driven shaft, i.e., gearbox input shaft.

01 - TYPES OF CLUTCHES USED IN TRANSMISSION SYSTEMS - CONSTRUCTION AND WORKING OF CONE CLUTCH

Using cones for the engaging surfaces enables greater torque to be transmitted without having to employ extremely heavy clutch springs.The angle of the cones cannot be made much smaller than about 20°. Because with a very small cone angle, the male cone will bind or stick in the female cone and it will be difficult to disengage the clutch. Further, a small quantity of wear on the cone surfaces will result in a considerable axial movement of the cone.Cone clutches are generally used in the synchromesh mechanisms in constant mesh gearboxes.

Hydraulic operated clutch

The hydraulic type clutch is used on vehicle where the clutch is to be remotely located and it may be difficult to run linkages from the clutch pedal to the clutch.

This type of clutch is also used on medium and heavy duty applications where springs of higher stiffness are required. When a clutch is to transmit high torques, the springs should be heavy in order to exert sufficient pressure on the friction disc. If the spring pressure is inadequate, the pressure plate and flywheel will slip on the friction disc. This slipping will quickly ruin the friction disc by increasing the wear of the linings on the disc.

01 - TYPES OF CLUTCHES USED IN TRANSMISSION SYSTEM - CONSTRUCTION AND WORKING OF HYDRAULIC CLUTCH

On the other hand, heavy spring pressure increases the pressure on the clutch release lever or fork. This, in turn, increases the pressure that the driver must apply on the clutch pedal. The hydraulic system used between the clutch pedal and clutch assembly reduces the clutch pedal pressure required to disengage the clutch, and thereby makes driving more easy and comfortable.

The principle of operation of a hydraulic operated multiple plate clutch. Hydraulic operation of the clutch has become increasingly popular in modern cars and heavy duty trucks.In this system, the clutch pedal operates the piston in the clutch master cylinder. The hydraulic pressure thus created in then transmitted through a tube to the slave cylinder, consisting of the piston i.e. pressure plate. This pressure moves the piston, thus releases the clutch. The main advantages of this system are that complicated clutch linkages, vibration and wear of the linkages are all eliminated.

Hydraulic Brake System of an Automobile | Construction and Working of Hydraulic Braking System | Components of an Oil Brake System

Construction and Working of a Hydraulic Brake System of an Automobile

Hydraulic operation of the brake systems has been the universal design for more than 60 years. The complete components of oil or hydraulic braking system consists of master cylinder; steel lines, rubber hoses, various pressure-control valves, and brake apply devices at each wheel.

01 - COMPONENTS OF AN OIL BRAKE SYSTEM - HYDRAULIC BRAKE CONSTRUCTION AND WORKING

Master Cylinder

The master cylinder is the start of the brake hydraulic system. It actually is a cylindrical pump. The cylinder closed at one end, and the flexible push rod extends from the other end. The push rod moves a pair of in-line pistons that produce the pumping action. The brake pedal lever moves the push rod this moves the pistons to draw fluid from a reservoir on top of the master cylinder. Piston action forces the fluid under pressure through outlet ports to the brake lines.

All master cylinders for vehicles built since 1967 have two pistons and pumping chambers. Motor vehicle safety standards involve this dual-brake system to provide hydraulic system operation in case one wheel brake assembly loses fluid. Because the brake hydraulic system closed, all the lines and cylinders are full of fluid at all times. The master cylinder develops system pressure the amount of fluid moved is only in less value.

01 - MASTER CYLINDER OF AN OIL BRAKE SYSTEM - HYDRAULIC BRAKE COMPONENTS CONSTRUCTION AND WORKING

Split Systems

Modern-day vehicles have split brake systems. The pre-1970’s vehicle had a single hydraulic system serving all four wheels. A leak anywhere in the system will result in a complete braking failure. The split system designed to prevent total system failure. This required the use of a dual-piston master cylinder and the inclusion of various valves. A split system is fed by one piston in the master cylinder and feeds two wheel brakes of the vehicle.

01 - WORKING OF AN OIL BRAKE SYSTEM - HYDRAULIC BRAKE TYPES AND WORKING

There are two types of split systems: diagonal and front/rear. The diagonal system has one system feeding a front-wheel brake and the rear opposing side wheel brake, that is left front and right rear. The second triangle split is to the other wheel brakes. One side or split feeds the rear-wheel brakes and the other feeds the front wheels. Both of these types have advantages and disadvantages, but each prevents complete system failure from a single leak.

Brake Lines and Hoses

The rigid lines or pipes of a brake hydraulic system made of steel tubing for system safety. Flexible rubber hoses join the wheel brakes to the rigid lines on the vehicle body or frame. The front brakes have a rubber hose at each wheel to allow for steering movement. Rear brakes may have different hoses at each wheel or a single hose connected to a line on the body or frame if the vehicle has a rigid rear axle. Brake lines and hoses contain the high-pressure fluid, and the fluid acts like a solid rod to transfer force to the wheel cylinders and caliper pistons.

Wheel Cylinders and Caliper Pistons

01 - WHEEL CYLINDER OF AN OIL BRAKE SYSTEM - HYDRAULIC BRAKE COMPONENTS CONSTRUCTION AND WORKING

Technically, the wheel cylinders of drum brakes and the caliper pistons of disc brakes are “slave” cylinders because they operate in response to the master cylinder. These hydraulic cylinders at the wheels change hydraulic pressure back into mechanical force to apply the brakes. Most late-model systems with drum brakes have a single, two-piston cylinder at each wheel. Hydraulic pressure enters the cylinder between the two pistons and forces them outward to act on the brake shoes. The shoes move outward, the lining contacts the drums to stop the car.

Hydraulic or Oil Braking system in Automobile

The caliper pistons for disc brakes also act in response to hydraulic pressure that enters a fluid chamber in the caliper. Hydraulic pressure in stationary caliper is applied to one or two pistons on each side of the caliper to force the pads against the rotor. Pressure is applied to a single piston in a movable caliper on the inboard side to force the inboard pad against the rotor. Hydraulic pressure is equal in all directions in a closed chamber. This equal pressure creates a reaction force that moves the outboard side of the caliper inward so that both pads grip the rotor.