Automotive Transmission: Components and Function

The transmission's mission: It is a set of organs formed by different mechanisms: the clutch, gearbox, differential, reducer group, etc. Its mission is to transmit the engine's rotation to the wheels, adapting it to the needs of the vehicle's driving conditions.

Objectives:

• Couple and uncouple the engine's rotation.
• Reduce or increase the engine's torque output.
• Transmit the output torque from the gearbox to the wheels through the transmission shafts, differentials, conical groups, and semi-shafts.

Resistances:

• Rolling resistance: (Caused by the vehicle's weight on the wheels, the type of terrain, the dimensions of the vehicle, and the tire's displacement).
• Air resistance: (Largely dependent on the vehicle's size, the speed of the vehicle, and the wind speed and direction).
• Slope resistance: (Dependent on the slope angle. When climbing, part of the vehicle's weight pushes in the opposite direction of travel, generating a force that opposes the force available to move the vehicle).
• Mechanical friction and useful power: (Generated as a consequence of friction between the parts and mechanical assemblies of the transmission).
• Inertia: (Generated by opposing the increase or decrease of the vehicle's speed).

Parts of the Engine Transmission:

It is not only the gearbox that allows movement, but also the engine's flywheel.

Clutch Mission:

It transmits power from the engine progressively during a gear change. It also allows the engine to be uncoupled, or disengaged, from the gearbox to change speeds.

Characteristics:

• Good mechanical resistance
• Elevated thermal resistance
• Great clutch adherence to prevent slipping and loss of power
• Progressiveness and elasticity

Parts of a Clutch:

• The clutch disc: A metal disc placed between the flywheel and the pressure plate. Its mission is to transmit the motion from the flywheel to the primary axis of the gearbox.
• Pressure plate: The part that presses the clutch disc against the flywheel.
• Elastic springs (diaphragm or coil): The element that exerts the thrust force of the pressure plate, forming a set with it and the outer casing.
• Cover or clutch housing: The piece that is externally attached to the pressure plate. It serves as housing for the elastic springs and protects all these mechanisms. It is bolted to the flywheel and rotates with it, thus also covering the clutch disc.
• The thrust collar: The piece that presses the center of the diaphragm or the oscillating levers, managing to separate the pressure plate and disengage the vehicle.
• Flywheel: Also part of the clutch assembly. The exterior of this face is the surface where the disc makes contact when pressure is exerted through the hub.

Trigger:

It allows you to make great efforts in pushing the collar with little force on the pedal. It uses a hydraulic circuit pump that is driven by the driver through the clutch pedal and transmits the hydraulic pressure to the slave cylinder that pushes the collar.

Hydraulic Clutch:

Further information is needed to complete this section.