Bicycle Transmission Manual Transmissions Or
Most semi-automatic transmissions used in cars and motorcycles are based on conventional manual transmissions or a sequential manual transmission, but use an automatic clutch system.However, some semi-automatic transmissions have also been based on standard hydraulic automatic transmissions, with a fluid coupling or torque converter.Less common than traditional (hydraulic) automatic transmissions, semi-automatic transmissions have nonetheless been made available on various car and motorcycle models, and currently remain in production.These systems are currently used on a variety of top-tier racing car classes; including Formula One, Indycar, and Touring car racing.
Other applications include motorcycles, trucks, buses, and railway vehicles.
Depending on the mechanical build, design, and age of the vehicle, they can use anything from, or a combination of hydraulic, pneumatic, or electric servos, solenoids, electrical sensors, electric switches, motors, processors, and actuators, to execute gear shifts when requested by the driver, typically when the driver moves or touches and moves the gearshift.
Most cars that have a semi-automatic transmission are not fitted with a standard clutch pedal, since the clutch is remotely controlled, solely by electronic equipment.
Similarly, most motorcycles with a semi-automatic transmission are not fitted with a conventional hand-clutch lever.
Once the clutch becomes automated, then the transmission becomes semi-automatic.
However, they still require full control of the manual gear selection, which is controlled by the driver.
This type of transmission is called a clutchless manual,or an automated manual.
Most semi-automatic transmissions in older passenger cars retain the normal H-pattern shifter of a manual transmission, similarly, semi-automatic transmissions on older motorcycles retain the conventional foot-shift lever, as on a motorcycle with a fully-manual transmission.
However, semi-automatics in newer motorcycles, racing cars, and other types of vehicles often use gear selection methods such as paddle-shifters near the steering wheel or triggers near the handlebars.
This control unit will then determine the optimal timing and torque required for smooth clutch engagement, based on input from these sensors.
The electronic control unit powers a hydro-mechanical unit to either engage or disengage the clutch, which is kept in close synchronization with the gear-shifting action the driver has started.
In some cases, the hydro-mechanical unit contains a servomotor coupled to a gear arrangement for a linear actuator, which uses hydraulic fluid from the braking system to impel a hydraulic cylinder which moves the main clutch actuator, therefore disengaging the clutch.
Can you find a person by their drivers license numberIn other cases, the internal clutch actuator may be completely electric (sometimes through the use of a solenoid ); where the main clutch actuator is powered by an electric motor, or even pneumatic; where the main clutch actuator is a pneumatic actuator, and uses compressed air to impel the pneumatic cylinder that disengages the clutch, allowing the driver to make a smooth gear change.
Xbx360 activation fileThe actuators and sensors which control the clutch are all connected and controlled through a dedicated electronic control unit or module.
Marketed as the Volkswagen Automatic Stickshift; a conventional three-speed manual transmission was connected to a vacuum -operated automatic clutch system.
The top of the gear shift was designed to easily depress and activate an electric switch, i.e., when touchedengaged by the drivers hand.
When pressed, the switch operated a 12-volt solenoid, in turn, operating the vacuum clutch servo, thus disengaging the clutch and allowing shifting between gears.
With the drivers hand removed from the gearshift, the clutch would re-engage automatically.
The transmission was also equipped with a torque converter, allowing the car to idle in gear, like an automatic.
This would allow the car to stop in any gear and start from a standing stop in any gear.