Automatic transmission friction control element
Friction controls are the main elements of an automatic transmission (automatic transmission). They transmit torque between the engine and transmission, and also enable gear shifting.
Types of friction controls:
There are two main types of friction controls:
* One-way clutches: Allow rotation to be transmitted in one direction only.
*Multi-plate clutches: Consist of multiple discs pressed between two cylindrical surfaces.
Design:
Friction controls consist of the following main components:
* Friction linings: Material that provides friction between discs.
* Rims: Steel or aluminum rims, usually grooved or perforated for better grip.
* Pistons and piston rings: Control the compression and expansion of discs.
*Springs: Apply pressure to compress the discs.
Working principle:
Friction controls operate as follows:
* When a particular gear is engaged, a solenoid or hydraulic piston directs pressure to the control piston. This compresses the discs, creating friction and transferring torque from the drive discs to the driven discs.
* To switch off the transmission, the pressure is released, the springs release the discs, and friction stops.
Specifications:
Friction control features include:
* Coefficient of Friction: A measure of the frictional force between discs.
* Heat Capacity: The ability to dissipate heat generated by friction.
*Strength and Durability: Ability to withstand loads and provide long service life.
Application:
Friction controls are used in various places in an automatic transmission, including:
* In clutch packs that engage and disengage gears.
* In the torque converter, which transfers torque from the engine to the transmission.
* In the overrunning clutch, which allows the engine to idle without being connected to the transmission.
Proper operation of the friction controls is critical to the smooth and efficient operation of the automatic transmission.