Hybrid cam-camless variable valve actuation system

A hydraulic valve actuator configured to selectively actuate a valve of an internal combustion engine between an open and closed position, comprising:

• an actuator housing having a piston cavity, an inlet port, a high pressure port in fluid communication with a high pressure fluid conduit, a low pressure port in fluid communication with a low pressure fluid conduit, and a solenoid;
• a piston disposed at least partially within the piston cavity and having a first surface at a first end in fluid communication with the inlet port, the first surface and actuator housing defining a volume;
• and
• an actuator valve disposed within the actuator housing in fluid communication with the inlet port, the high pressure port, the low pressure port and the volume through the inlet port, the actuator valve including a magnetic spool valve member responsive to the solenoid such that the magnetic spool valve member is positioned in one of a first position and second position when the solenoid is activated,
• wherein the low pressure port is in fluid communication with a first spool channel of the magnetic spool valve member, the inlet port and the volume when the magnetic spool valve member is in the first position, and
• wherein the high pressure port is in fluid communication with a second spool channel of the magnetic spool valve member, the inlet port and the volume when the magnetic spool valve member is in the second position.

An internal combustion engine, comprising:

• an engine block;
• a cylinder head mounted to the engine block to form at least one combustion chamber, the cylinder head defining a first intake port, a first exhaust port and a second port, the second port comprising one of an intake port and an exhaust port;
• a first intake valve mounted to the cylinder head and arranged at least partially within the first intake port, the first intake valve being movable between an opened position and a closed position to selectively open and close the first intake port, respectively;
• a first exhaust valve mounted to the cylinder head and arranged at least partially within the first exhaust port, the first exhaust valve being movable between an opened position and a closed position to selectively open and close the first exhaust port, respectively;
• a second valve mounted to the cylinder head and arranged at least partially within the second port, the second valve being movable between an opened position and a closed position to selectively open and close the second port, respectively;
• a rotating cam mechanically coupled to the first intake valve and the first exhaust valve, the rotating cam actuating the first intake valve and the first exhaust valve between the open and closed positions;
• and
• a hydraulic valve actuator coupled to the second valve to selectively actuate the second valve between the open and closed positions, wherein the hydraulic valve actuator further comprises:
• an actuator housing having a piston cavity, an inlet port, a high pressure port in fluid communication with a high pressure fluid conduit, and a low pressure port in fluid communication with a low pressure fluid conduit;
• a piston disposed at least partially within the piston cavity and having a first surface at a first end in fluid communication with the inlet port, the first surface and actuator housing defining a volume;
• and,
• an actuator valve disposed within the actuator housing in fluid communication with the inlet port, the high pressure port, the low pressure port and the volume through the inlet port.