Editing Continuously variable transmission (section)

=== Farm and earthmoving equipment ===
[[Combine harvester]]s used variable belt drives as early as the 1950s. Many small [[tractor]]s and self-propelled [[Lawn mower|mowers]] for home and garden use simple rubber belt CVTs. Hydrostatic CVTs are more common on the larger units.{{such as|date=July 2020}} In mowing or harvesting operations, the CVT allows the forward speed of the equipment to be adjusted independently of the engine speed; this allows the operator to slow or accelerate as needed to accommodate variations in the thickness of the crop.

Hydrostatic CVTs are used in small- to medium-sized agricultural and earthmoving equipment. Since the engines in these machines are typically run at constant power output (to provide hydraulic power or to power machinery), losses in mechanical efficiency are offset by enhanced operational efficiency. For example, in earthmoving equipment, the forward-reverse shuttle times are reduced. The speed and power output of the CVT is used to control the travel speed and sometimes steering of the equipment. In the latter case, the required speed differential to steer the equipment can be supplied by independent CVTs, allowing the steering to be accomplished without several drawbacks associated with other skid steer methods (such as braking losses or loss of tractive effort).

The 1965 [[Wheel Horse]] 875 and 1075 garden tractors were the first such vehicles to be fitted with a hydrostatic CVT. The design used a variable-displacement swash-plate pump and fixed-displacement gear-type hydraulic motor combined into a single compact package. Reverse ratios were achieved by reversing the flow of the pump through over-centering of the swashplate. Acceleration was limited and smoothed through the use of pressure accumulator and relief valves located between the pump and motor, to prevent the sudden changes in speed possible with direct hydraulic coupling. Subsequent versions included fixed swash plate motors and ball pumps.{{citation needed|date=July 2020}}

The 1996 ''Fendt Vario 926'' was the first heavy-duty tractor to be equipped with a IVT transmission. It is not the same thing as a hydrostatic CVT. Over 100,000 tractors have been produced with this transmission.<ref name="Fendt History">{{cite web|title=Fendt History|url=http://www.fendt.com/us/history.asp|access-date=26 October 2012|website=fendt.com}}</ref>