A speed changer is an element by means of which the speed governing
system can be adjusted to change the speed of the generator set under
conditions of single unit, isolated load operation, or to change the
power output under conditions of parallel operation with an independent
power source. Popularity of Speed Changers
By the mid of 1950s, a number of competing tractors offered actual multi-speed transmissions. The Bradely walkbehind, opted for a variable pitch pulley arrangement that mounted on an arm midway between the engine and the clutch pulley. Separate belts ran from the variable pulley forward to the engine and from the variable pulley back to the clutch. A handle bar mounted lever placed slightly pressure on the arm holding the variable pulley. Pushing forward forced one belt up in the pulley while the other went down. Backward pressure caused the opposite effect. The result of the moving belts in or out was a change in ratio. It came standard with a reverse capability and a feature called a 'speed changer'. Speed changers gave the tractor infinitely variable ground speed capability without changing engine RPM.
A dual speed changer allows operators access to increased power. Hitting the dual power button will mean the selected speed is reduced by a specified percentage. Motor actuated speed changer provides a means for remote speed control on hydraulic governors. They provide a controlled rate for speed or load changes.
