In a camshaft free combustion engine a pressure fluid, such as a liquid or a gas, is used to achieve a displacement/opening of one or more engine valves. This means that the camshafts, and related equipment, that conventional combustion engines use to open engine valves to let air in respective let exhaust fumes out from the combustion chamber, has been replaced by a less volume demanding and more controllable system.
In an engine that is constructed for significant angular momentum outputs, the pressure in the combustion chamber is increasing proportional to an increased angular momentum output, and the force that is required to open the valve actuator to open the, in relation to the combustion chamber inward opening, engine valve consequently also increases proportional to an increased angular momentum output. At high numbers of revolutions, such as 6-8000 rpm, a very fast opening of the engine valve is also required for the filling of air respective evacuation of exhaust fumes from the engine cylinder not to be restricted. These requirements, i.e. the need for an extremely fast opening at high frequencies in a high performance engine having high counter pressure in the combustion chamber of the engine at the opening of the exhaust valves, require the pressure of the pressure fluid upstream of the valve actuator to be high, in the order of 8-30 bar. Downstream the valve actuator, the pressure fluid has a lower pressure, in the order of 3-6 bar.
At high numbers of revolution and high engine loads, the pressure difference between the low pressure side and the high pressure side should be in the order of 15-20 bar to achieve a correct operation of the valve actuators, and when the engine is idle running, or at low numbers of revolution and low loads, the pressure difference between the low pressure side and the high pressure side only needs to be in the order of 2-5 bar. The lower pressure difference at low numbers of revolution is desirable when the pressure is increased by way of a compressor from the low pressure side to the high pressure side, and at the pressure increase, energy consumption occurs that increases concurrently with increased pressure on the high pressure side.
In situations that require fast acceleration and/or very fast change from low numbers of revolution and low load to high numbers of revolutions and high load, for example when entering on a busy main road or at a sudden overtaking of a slow moving vehicle, the pressure difference between the low pressure side and the high pressure side must immediately be increased to achieve the acceleration that the driver requires. A conventional compressor is dimensioned to be able to generate pressure differences with greatly varying magnitude, they are however not dimensioned to satisfy the requirement of immediate shifts between separate great pressure difference levels and pressure fluid flows.
Furthermore, there is inertness in the present systems to go from a great pressure difference to a small pressure difference, i.e. when the vehicle again is operated at low numbers of revolution after the short/temporary rise in numbers of revolutions/engine load, it will take time before the pressure difference and thereby the high energy consumption has decreased to a desired level.