A differential is a gear train with three drive shafts that has the property that the rotational speed of one shaft is the average of the speeds of the others. A common use of differentials is in motor vehicles, to allow the wheels at each end of a drive axle to rotate at different speeds while cornering. Other uses include clocks and analogue computers. Differentials can also provide a gear ratio between the input and output shafts. For example, many differentials in motor vehicles provide a gearing reduction by having fewer teeth on the pinion than the ring gear.
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.
An epicyclic gear train is a gear reduction assembly consisting of two gears mounted so that the center of one gear revolves around the center of the other. A carrier connects the centers of the two gears and rotates, to carry the planet gear(s) around the sun gear. The planet and sun gears mesh so that their pitch circles roll without slip. If the sun gear is held fixed, then a point on the pitch circle of the planet gear traces an epicycloid curve.
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.
A limited-slip differential (LSD) is a type of differential gear train that allows its two output shafts to rotate at different speeds but limits the maximum difference between the two shafts. Limited-slip differentials are often known by the generic trademark Positraction, a brand name owned by General Motors and originally used for its Chevrolet branded vehicles.
Global Hybrid Cooperation, formerly Advanced Hybrid System 2 (AHS2), is a set of hybrid vehicle technologies jointly developed by General Motors, Daimler, and Chrysler LLC, with BMW joining in 2005. It uses 2 or 3 planetary gearsets in an automatic transmission: one on the internal combustion engine (ICE) side paired with a second, forming the compound split, and possibly one third additional planetary gearset to multiply the number of fixed gear ratios. General Motors has stopped using the "AHS2" name as of 2006, preferring to call it simply a two-mode hybrid system.
Hydramatic is an automatic transmission developed by both General Motors' Cadillac and Oldsmobile divisions. Introduced in 1939 for the 1940 model year vehicles, the Hydramatic was the first mass-produced fully-automatic transmission developed for passenger automobile use.
TorqueFlite is the trademarked name of Chrysler Corporation's automatic transmissions, starting with the three-speed unit introduced late in the 1956 model year as a successor to Chrysler's two-speed PowerFlite. In the 1990s, the TorqueFlite name was dropped in favor of alphanumeric designations, although the latest Chrysler eight-speed automatic transmission has revived the name.
Turbo-Hydramatic or Turbo Hydra-Matic is the registered tradename for a family of automatic transmissions developed and produced by General Motors. These transmissions mate a three-element turbine torque converter to a Simpson planetary geartrain, providing three forward speeds plus reverse.
The Rohloff Speedhub is an epicyclic internal hub gear for bicycles, developed and patented by Rohloff AG. It has been manufactured and marketed by that company since 1998. The Speedhub 500/14 has 14 equally spaced, sequential, non-overlapping gear ratios operated by a single twistgrip. The overall gear range is 526%, meaning the highest gear is 5.26 times as high as the lowest gear. Individual gear shifts when shifting up give an increase of about 13.6%.
Allison Transmission Holdings Inc. is an American manufacturer of commercial duty automatic transmissions and hybrid propulsion systems. Allison products are specified by over 250 vehicle manufacturers and are used in many market sectors, including bus, refuse, fire, construction, distribution, military, and specialty applications.
The BorgWarner T-5 is a 5-speed manual transmission for longitudinal engine automobiles. It includes one overdrive gear, a lightweight aluminum housing, and adaptability for four wheel drive use.
The 4L60E is a series of automatic transmissions from General Motors. Designed for longitudinal engine configurations, the series includes 4 forward gears and 1 reverse gear. The 4L60E is the electronically commanded evolution of the Turbo-Hydramatic 700R4, originally produced in 1982.
The Turboglide is a Chevrolet constant torque, continuously variable automatic transmission first offered as an option on Chevrolet V8 passenger cars for 1957. It consisted of a turbine-driven planetary gearbox with a 'switch pitch' dual-pitch torque converter stator. It had a die-cast aluminum transmission case, like Packard's Ultramatic of 1956. Turboglide cost about $50 more than the Powerglide 2-speed automatic. It was available in all V8-powered 1957-1961 Chevrolet models except the Corvette. General Motors produced 646,000 of these transmissions during its production.
The Ravigneaux gearset is a double planetary gear set, invented by Pol Ravigneaux, who filed a patent application on July 28, 1949, in Neuilly-sur-Seine France. This planetary gear set, commonly used in automatic transmissions, is constructed from two gear pairs, ring–planet and planet–planet. The gearset provides four forward gear ratios and reverse by braking or restraining various elements of the mechanism.
The GM MR6/F40 six-speed manual transaxle was first developed for GM Europe by Saab Powertrain, for use in Saab and Opel applications. Originally a design developed by GM Powertrain Sweden Södertälje - Europe six-speed manual transaxle was originally built by Saab in its transmission plant in Gothenburg, Sweden (2002-2003) but production was moved to Opel in Rüsselsheim am Main, Germany since 2004. Its first use in Europe was the new Saab 9-3 2003-2011, while first use in North America was the same, in the Aero model. It is also used in 9-5 2010-2012 models.
The Simpson planetary gearset is a compound planetary gear train consisting of two planetary gearsets sharing a common sun gear. A Simpson gearset delivers three forward gears and one reverse, plus neutral, and is commonly employed in three and four ratio automatic transmissions. It is one of the several designs invented by American engineer Howard Simpson.
9HP is the trademark name for the ZF Friedrichshafen 9-speed automatic transmission models for transverse engine applications, designed by ZF's subsidiary in Saarbrücken and built in Gray Court, South Carolina. It is used in front-wheel drive and all-wheel drive vehicles.
9G-Tronic is Mercedes-Benz's trademark name for its 9-speed automatic transmission, starting off with the W9A 700 as core model.
The Volvo I-Shift is an automated manual transmission developed by Volvo subsidiary Volvo Powertrain AB for Volvo Trucks and Volvo Buses, with 12 forward gears and 4 reverse gears. It became available for trucks in 2001 and later buses in 2004.
