Pressure activated rotary clutch

A pressure activated rotary hydraulic clutch comprising:

• a sealed unit enclosing hydraulic fluid;
• said unit being mounted to and rotatable about a rotatable shaft;
• said shaft defining an axial direction and having a leading end disposed in said unit;
• said unit including a circumferentially extending outer wall and also a circumferentially extending inner wall;
• said inner wall including at least one lobe having a major dimension and a minor dimension from said shaft;
• a hydraulic fluid passageway in said unit and having an inlet in said inner wall on one side of said minor dimension and an outlet in said inner wall on another side of said minor dimension;
• a flow control valve disposed in said fluid passageway for controlling hydraulic fluid flow therethrough;
• a flow control valve actuator in communication with said flow control valve for operating said flow control valve;
• a rotor fixed to said leading end within said inner wall and rotatable with said shaft;
• said rotor being in proximity with said minor dimension of said lobe;
• a vane on said rotor for moving said hydraulic fluid through said fluid passageway when the passageway is open and said shaft is rotated and for driving said unit through said hydraulic fluid when said passageway is restricted;
• and
• whereby said unit rotates independently of said shaft and rotor when said passageway is unrestricted and said unit rotates with said shaft and rotor when said valve is operated to restrict fluid flow through said fluid passageway.