The Power Factor

Farm tractors are run by diesel engines, the power ranging from 18 to 575 horse-power. Lawn tractors are less tough than garden tractors. Ten to 25 horsepower is used for smaller tasks like mowing grass patches and landscaping. Most tractors can transfer power to other machines like the baler, slasher, or mower. Previously, belts were wrapped around pulleys to power stationary equipment. Today, tractors make use of the power take-off shaft (PTO) to give rotary powers to the machinery that is standing and needs to be pulled. Modern tractors provide external hydraulic fluid and electrical power. Many farm tractors also use manual power transmission. Several sets of gears are divided according to speed ratio. In order to change the ratio, the tractor has to be stopped. It is not necessary to change the gear to reverse. One only has to choose a lever. Power shifting technique was introduced from the sixties allowing for more modern continuously variable transmission. This allows greater control to the driver of the tractor.