Multi-disk clutch

A dual clutch arrangement including two clutch areas, each with a pressure plate connected to a housing arrangement for rotation in common around an axis of rotation (A) and which can be shifted in the axial direction with respect to the housing; and a clutch disk, the friction surface areas of which can be clamped between the respective pressure plate and an opposing support arrangement. Each of the clutch disks is designed to be connected nonrotatably to a different power takeoff element. In addition a clutch cooling arrangement, through which a coolant can flow, is installed adjacent to the clutch areas.

Diagram of car showing clutch location

Clutch

A clutch is a mechanism for transmitting rotation, which can be engaged and disengaged. Clutches are useful in devices that have two rotating shafts. In these devices, one shaft is typically driven by a motor or pulley, and the other shaft drives another device. In a drill, for instance, one shaft is driven by a motor, and the other drives a drill chuck. The clutch connects the two shafts so that they can either be locked together and spin at the same speed (engaged), or be decoupled and spin at different speeds (disengaged).

continuously variable transmission (CVT).

A CVT has a nearly infinite range of gear ratios. In the past, CVTs could not compete with four-speed and five-speed transmissions in terms of cost, size and reliability, so you didn't see them in production automobiles. These days, improvements in design have made CVTs more common. The Toyota Prius is a hybrid car that uses a CVT.

Mercedes-Benz C-class sport coupe, six-speed manual transmission, graphic illustration

Mercedes-Benz Actros, manual transmission

Manual transmission

A manual transmission (also known as a stick shift or just 'stick', 'straight drive', or standard transmission) is a type of transmission used in automotive applications. Manual transmissions often feature a driver-operated clutch and a movable gear selector. Most automobile manual transmissions allow the driver to select any forward gear at any time, but some, such as those commonly mounted on motorcycles and some types of racing cars, only allow the driver to select the next-highest or next-lowest gear ratio. This second type of transmission is sometimes called a sequential manual transmission.

Manual transmissions are characterized by gear ratios that are selectable by engaging pairs of gears inside the transmission. Conversely, most automatic transmissions feature epicyclic (planetary) gearing controlled by brake bands and/or clutch packs to select gear ratio. Automatic transmissions that allow the driver to manually select the current gear are called semi-automatic transmissions.

Contemporary automotive manual transmissions are generally available with four to six forward gears and one reverse gear, although manual transmissions have been built with as few as two and as many as eight gears. Tractor units have at least 10 gears and as many as 24. Some manuals are referred to by the number of forward gears they offer (e.g., 5-speed) as a way of distinguishing between automatic or other available manual transmissions. Similarly, a 5-speed automatic transmission is referred to as a 5-speed automatic.

Other types of transmission in mainstream automotive use are the automatic transmission, semi-automatic transmission, and the continuously variable transmission.

Manual transmissions come in two basic types: simple non-synchronous systems, where gears are spinning freely and their relative speeds must be synchronized by the operator to avoid noisy and damaging "clashing" and "grinding" when trying to mesh the rotating teeth; and synchronized systems, which eliminate this necessity while changing gears.