Variable compression ratio connecting rod system with rotary actuator

A variable compression connecting rod system having a piston pin defining a piston pin axis, a crankpin of a crankshaft defining a crankpin axis, and a source of pressurized fluid, the improvement comprising:

• a connecting rod having a first end associated with the piston pin and a second end located distally opposite the first end and associated with the crankpin;
• a hydraulically actuated eccentric rotor rotatable about at least one of the piston pin axis and the crankpin axis associated with at least one of the first and second ends between first and second angular positions, the eccentric rotor and the connecting rod defining a first expandable chamber and a second expandable chamber, the eccentric rotor having different first and second radial distances aligned with a longitudinal axis of the connecting rod when in the first and second angular positions for varying a longitudinal length of the connecting rod between the piston pin axis and the crankpin axis, the first radial distance corresponding to a minimum connecting rod length and the second radial distance corresponding to a maximum connecting rod length;
• at least one fluid conduit allowing fluid communication between the first and second expandable chamber and the source of pressurized fluid,
• wherein the eccentric rotor includes a first vane and a second vane disposed on an exterior surface of the eccentric rotor, each of the first and second vanes defining the first expandable chamber and the second expandable chamber, respectively, located on opposite sides of a corresponding vane, the eccentric rotor rotatable in a clockwise direction and a counterclockwise direction in response to fluid pressure acting against the first and second vanes within the corresponding first and second expandable chambers and wherein the first vane and the second vane are approximately 180° apart;
• and
• at least one oil control valve having a position to isolate the eccentric rotor from fluid communication with the source of pressurized fluid or a vent to hold the eccentric rotor in a current position.

A method of assembling a variable compression connecting rod system comprising:

• forming a connecting rod to be mountable with respect to a piston pin and a crankpin, the connecting rod having a first end to be associated with the piston pin defining a piston pin axis and a second end located distally opposite the first end to be associated with the crankpin defining a crankpin axis, the connecting rod having an eccentric-rotor-receiving aperture formed therein;
• inserting at least one hydraulically actuated eccentric rotor to be rotatable about at least one of the piston pin and crankpin axes associated with at least one of the first and second ends, the eccentric rotor operable in response to fluid communication with at least one expandable chamber defined between the eccentric rotor and the connecting rod for rotating the eccentric rotor, the eccentric rotor having different first and second radial distances movable into alignment with a longitudinal axis of the connecting rod in response to fluid pressure action acting on the eccentric rotor for varying a longitudinal length of the connecting rod between the piston pin and crankpin axes, the first radial distance corresponding to a minimum connecting rod length and the second radial distance corresponding to a maximum connecting rod length;
• forming at least one fluid conduit allowing fluid communication between the at least one expandable chamber and a source of pressurized fluid,
• forming a first vane and a second vane on an exterior surface of the eccentric rotor, each of the first and second vanes defining the first expandable chamber and the second expandable chamber, respectively, located on opposite sides of a corresponding vane, wherein the eccentric rotor is rotatable in a clockwise direction and a counterclockwise direction in response to fluid pressure acting against the first and second vanes within the corresponding first and second expandable chambers and wherein the first vane and the second vane are approximately 180° apart;
• and
• inserting at least one oil control valve having a position to isolate the eccentric rotor from fluid communication with the source of pressurized fluid or a vent to hold the eccentric rotor in a current position.