The invention relates to some rotary valves for heat engines, pumps and compressors to replace known valves – with go forth alternative motion - from existing engines, pumps and compressors, and all installations and devices that can benefit from this solution.
The rotary valve comprises a valve block, generally made of light alloys or ceramic material made by means of known technology, shaped corresponding to its purpose and the ends are provided with one or two bearings and a drive shaft. The body of the valve consists of a metal or ceramic disc with one or more fluid flow holes and a shaft for coupling the drive shaft.

It is here where a cycle occurs every half rotation axis, namely a quarter turn if two holes are provided.

The difference between the version with a vertical disc and a hole on the circumference (according to fig.1) and the “simple” version consists in an open cavity on the circumference, positioned radially and diametrically opposite to balance the weight, some balancing holes; this version takes one cycle to complete each rotation.

The horizontal version (according to fig. 2) differs from the vertical one in the horizontal position of the valve plate and the drive mode; the drive shaft is positioned vertically relative to the combustion chamber; so each valve can be operated by a timing chain or toothed belt distribution- themselves known, and not represented in the drawing.

The version of the truncated cone (according to fig.3) is composed similarly to the main one, the difference consists in the valve body which is not a plate, but a single or double truncated cone, concave or convex, provided with intake holes - of fluid flow.

The technical problem that the invention solves is that using simple and accurate rotary valves with a small number of rotating only moving parts leads to the elimination of noise and vibration. This is an important factor in reducing general wear and, thus, greater reliability in operation, a more constructive simplicity which brings many advantages not only in machining, assembly, service but also in weight, cost, energy consumption reduction; the risk of damage to the piston head by the valves is eliminated as well. Other advantages are reducing the content (percentage) of special steel, high and consistent quality of products, the possibility of using ceramic materials in their construction, a safer operation of motors, pumps and compressors, etc.

Production costs are essentially reduced, on one hand, because ceramics and cermets are used instead of special steels and, on the other hand, because of the lower number of parts, the manufacture through sintering- stamping, and because of the reduced number of operations in machining.