A technique described in Patent Document 1 has been known as a conventional technique of a belt type continuously variable transmission in which a driving force is transmitted with a belt being wound across a pair of pulleys having a variable groove width.
The belt type continuously variable transmission described in Patent Document 1 electrically controls an operation of a hydraulic cylinder for changing the groove width of the pulley on the basis of signals from various sensors such as a vehicle speed sensor and an accelerator pedal position sensor so that the transmission ratio in the belt type continuously variable transmission is changed as desired.
Unfortunately, the belt type continuously variable transmission described in Patent Document 1 has a disadvantage that a complicated configuration is required for electrically controlling the hydraulic cylinder.