Schematic view of the Saxomat automatic clutch control valves unit: 1 – solenoid, 2 – solenoid valve, 3 – vacuum check valve, 4 – pressure reducing valve, 5 – vacuum regulator valve, A – vacuum chamber, B – intermediate chamber, C – atmosphere chamber. The solenoid valve is shown activated, the clutch is fully depressed.
Saxomat was a type of automatic clutch available as an option on the Fiat 1800, Lancia Flaminia, Saab 93, Borgward Isabella, Goliath/Hansa 1100, Auto Union 1000, Ford Taunus, Trabant, as well as certain models from BMW, Opel, Steyr-Puch, NSU, Glas, Wartburg and Volkswagen. Opel sold it as Olymat; Trabant and Wartburg named the system Hycomat. The Hydrak, used in some Mercedes-Benz vehicles between 1957 and 1961, was a similar system with a hydrodynamic torque converter in place of the Saxomat's centrifugal clutch, this H.T.C. system was standard on NSU Ro 80 and was optional on the Porsche 911 (Sportomatic). The system also reappeared in the 1990s as Saab Sensonic, but Saab shelved that technology since 1998. Hyundai also reintroduced similar concept as the Intelligent Manual Transmission (iMT) in 2020 with the latest generation Hyundai i20.
Cars with a Saxomat clutch did not have a clutch pedal. The Saxomat consisted of two independent systems: the centrifugal clutch, and the servo clutch. The centrifugal clutch was engaged above certain engine speed by centrifugal force acting on spinning weights inside the clutch, similar to a centrifugal governor.
The servo clutch used an electric switch that supplied manifold vacuum via an actuator valve to a reservoir that disengaged the clutch. The clutch is disengaged automatically whenever the gear-shift lever was touched.
A clutch is a mechanical device that allows an output shaft to be disconnected from a rotating input shaft. The clutch's input shaft is typically attached to a motor, while the clutch's output shaft is connected to the mechanism that does the work.
An automatic transmission is a multi-speed transmission used in motor vehicles that does not require any input from the driver to change forward gears under normal driving conditions. Vehicles with internal combustion engines, unlike electric vehicles, require the engine to operate in a narrow range of rates of rotation, requiring a gearbox, operated manually or automatically, to drive the wheels over a wide range of speeds.
A manual transmission (MT), also known as manual gearbox, standard transmission, or stick shift, is a multi-speed motor vehicle transmission system where gear changes require the driver to manually select the gears by operating a gear stick and clutch.
In mechanical or automotive engineering, a freewheel or overrunning clutch is a device in a transmission that disengages the driveshaft from the driven shaft when the driven shaft rotates faster than the driveshaft. An overdrive is sometimes mistakenly called a freewheel, but is otherwise unrelated.
A semi-automatic transmission is a multiple-speed transmission where part of its operation is automated, but the driver's input is still required to launch the vehicle from a standstill and to manually change gears. Semi-automatic transmissions were almost exclusively used in motorcycles and are based on conventional manual transmissions or sequential manual transmissions, but use an automatic clutch system. But some semi-automatic transmissions have also been based on standard hydraulic automatic transmissions with torque converters and planetary gearsets.
Engine braking occurs when the retarding forces within an internal combustion engine are used to slow down a motor vehicle, as opposed to using additional external braking mechanisms such as friction brakes or magnetic brakes.
The modern usage of the automotive term manumatic denotes an automatic transmission that allows the driver to select a specific gear, typically using paddle-shifters, steering wheel-mounted push-buttons, or "+" and "-" controls on the gear selector.
A preselector gearbox is a type of manual transmission mostly used on passenger cars and racing cars in the 1930s, in buses from 1940–1960 and in armoured vehicles from the 1930s to the 1970s. The defining characteristic of a preselector gearbox is that the gear shift lever allowed the driver to "pre-select" the next gear, usually with the transmission remaining in the current gear until the driver pressed the "gear change pedal" at the desired time.
The Honda FC50, also known as the Honda Beat, is a 50 cc (3.1 cu in) scooter manufactured by Honda in 1983. It was produced mainly for the Japanese domestic market — although both new and used models were exported from Japan—making it a fairly hard-to-find scooter. It was available in red, black, or white.
The automated manual transmission (AMT) is a type of transmission for motor vehicles. It is essentially a conventional manual transmission equipped with automatic actuation to operate the clutch and/or shift gears.
Wartburg is an East German automotive brand used for cars manufactured at VEB Automobilwerk Eisenach. Origins of the brand date back to 1898. The name derives from Wartburg Castle on one of the hills overlooking the town of Eisenach where the cars were made. From the 1950s until the late 1980s, Wartburgs featured a three-cylinder two-stroke engine with only seven major moving parts. Production ended in April 1991, and the factory was acquired by Opel.
A transmission control unit (TCU), also known as a transmission control module (TCM), or a gearbox control unit (GCU), is a type of automotive ECU that is used to control electronic automatic transmissions. Similar systems are used in conjunction with various semi-automatic transmissions, purely for clutch automation and actuation. A TCU in a modern automatic transmission generally uses sensors from the vehicle, as well as data provided by the engine control unit (ECU), to calculate how and when to change gears in the vehicle for optimum performance, fuel economy and shift quality.
A centrifugal clutch is an automatic clutch that uses centrifugal force to operate. The output shaft is disengaged at lower rotational speed and engages as the output increases to a certain speed. It is often used in mopeds, underbones, lawn mowers, go-karts, chainsaws, mini bikes, and some paramotors and boats to keep the engine from stalling when the output shaft is slowed or stopped abruptly, and to remove load when starting and idling. It has been superseded for automobile applications by the fluid coupling, torque converter and automated manual transmissions.
The name Autostick has been used for a Volkswagen semi-automatic transmission, which is a vacuum-operated automatic clutch system, coupled with a conventional 3-speed manual transmission. The "AutoStick" system designed by Chrysler allows for manual selection of gears with a standard hydraulic automatic transmission, also known as a manumatic.
The F35 is a Saab-designed five-speed manual transmission built in Saab’s Gothenburg, Sweden, powertrain plant. This extensively tested manual transmission was originally introduced in the 1984 Saab 9000, and was later used in the Saab 900, 9-3 and 9-5, Saturn Ion Redline, Chevrolet Cobalt SS, Chevrolet HHR SS and various GM/Opel transverse engine front-wheel drive applications.
A motorcycle transmission is a transmission created specifically for motorcycle applications. They may also be found in use on other light vehicles such as motor tricycles and quadbikes, go-karts, offroad buggies, auto rickshaws, mowers, and other utility vehicles, microcars, and even some superlight racing cars.
The Opel Rekord Series A is a large family car introduced in March 1963, by Opel as a replacement for the Opel Rekord P2. It was fractionally shorter but also wider than its predecessor with a wheelbase approximately 10 cm longer.
The Opel Rekord Series B is a large family car that was introduced in August 1965 by Opel as a replacement for the Opel Rekord Series A and stopgap until the delayed Rekord C was ready for sale. Produced only until July 1966, it shared the wheelbase and 1,696 mm (66.8 in) width of its predecessor, but the front and rear panels were restyled to give it a more modern appearance.
The Opel Rekord Series C is a large family car that was introduced in August 1966, by Opel as a replacement for the short-lived Opel Rekord Series B. It was slightly larger all round than its predecessor, from which it inherited most of its engines. It continued in production until replaced by the Opel Rekord Series D at the end of 1971.
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