Continuously variable transmission

A clutch system for a continuously variable transmission, the clutch system coupled to a shaft that is rotatable about a longitudinal axis, comprising:

• a stationary sheave coupled to the shaft;
• a movable sheave comprising a slot, and moveably coupled to the shaft, the movable sheave being movable with respect to said stationary sheave along the longitudinal axis;
• a positional motor coupled to the moveable sheave and configured to cause said moveable sheave to move closer or further from the stationary sheave;
• and
• the moveable sheave and the stationary sheave coupled via a slot, said slot is generally at a helical angle from said longitudinal axis.

A vehicle comprising a continuously variable transmission system, wherein the continuously variable transmission system comprises:

• a stationary sheave coupled to a shaft;
• a movable sheave journalled about the shaft, the movable sheave being movable closer to or further from the stationary sheave along a longitudinal axis of rotation;
• a motor coupled to the moveable sheave and configured to cause said moveable sheave closer or further from the stationary sheave;
• and
• the stationary sheave and the moveable sheave coupled with a pin and slot, wherein said slot is generally at a helical angle from said longitudinal axis of rotation and configured to reduce the longitudinal force needed to move said moveable sheave relative to said stationary sheave, with respect to a moveable sheave with a slot generally parallel to said longitudinal axis.

A method of controlling a CVT transmission comprising:

• sending engine and transmission system signals to a microprocessor;
• calculating a speed ratio using the engine and transmission system signals;
• selecting a required speed ratio from a look up table;
• determining a transmission control motor speed and direction;
• and
• sending a signal to the transmission control motor to change the speed ratio to match the required speed ratio.