Sturman DHOS™ Valve Actuation Module

The high power to mass ratio of electrohydraulic actuators facilitates the development of camless engines where timing the lift and closing of the intake and exhaust valves for different engine speed and load conditions has the potential to improve efficiency and torque and reduce emissions.

In its simplest form the design of the DHOS™ Valve Actuation Module consists of an electrohydraulic actuator (featuring a Sturman Digital Valve) acting upon a spring returned engine valve. The replacement of the mechanical valvetrain with a fully variable camless actuation system provides the operational flexibility required to control mass transfer of intake air and exhaust into and out of the engine cylinders.