Editing Lego Technic (section)

===Gears===
[[Gear]]s have been included within Lego Technic sets since 1977 as a way of transferring rotary power and gearing up or down the speed. Gears come in several sizes: 8-tooth, 16-tooth, 24-tooth, and 40-tooth spur gears; 12-tooth, 20-tooth, 28-tooth, and 36-tooth double bevel gears; and 12-tooth and-20 tooth single bevel gears. The double bevel gears are cut so they can also be meshed as spur gears. There is also a 16-tooth spur clutch gear, a 20-tooth double bevel clutch gear, and a 24-tooth friction gear that slips when a certain amount of torque is put on it to prevent motors from damaging any parts or burning themselves out.

In addition to standard gears, some kits include a rack, a clutch, and even [[worm gear]]s and [[differential gear]]s. The original differential from 1980 had a 28 tooth bevel gear, designed to be meshed with the 14 tooth bevel gears (replaced by the 12 tooth gears) to give 2:1 reduction. They can also be meshed with the newer double bevel gears. It was replaced in 1994 by a newer design incorporating 16-tooth and 24-tooth gears on opposite sides of the casing. The casing holds three 12 tooth bevel gears inside. In 2008, an updated version of the original differential has been released, optimised for studless construction with a 28 tooth bevel gear on the outside and three 12 tooth gears on the inside. With the release of the 'Top Gear Rally Car' ([[#Set42109|42109]]) in 2020, yet another differential was created with a 28 tooth double bevel gear and five 12 tooth gears on the inside so that the differential could be rotated with gears above and next to the differential.

Chain links were also introduced as an additional way of connecting gears. Tension (resulting from the correct number of chain-link parts used), along with the combination of gearwheel-sizes used, is critical to reliable operation. 8-tooth gears are not recommended for this purpose.

[[Volvo Construction Equipment]] used a Lego model to develop an electric [[wheel loader]].<ref>{{cite web |last1=Altl |first1=Blair |title=Volvo's prototype autonomous electric construction vehicle started out as a LEGO Technic set |url=https://electrek.co/2021/10/27/volvo-lx03-lego-technic/ |website=[[Electrek]] |date=27 October 2021}}</ref>