HYDRAULIC DRIVING UNIT FOR THE CONTROL RODS OF NUCLEAR REACTORS

摘要

Hydraulic drives for control rods in nuclear reactors can comprise a cylinder (3) which moves with respect to a piston (1), a plurality of successive projections (15) and depressions (16) being provided at right angles to the direction of motion on the piston and/or cylinder. Hydraulic centring which prevents interlocking of the piston (1) and cylinder (3) can be obtained adjacent to some projections (15) and depressions (16) with the aid of a guide surface (19) whose length in the direction of motion is greater than the spacing of two projections (15) and whose diameter (D) is between that of the projections (D1) and depressions (D2). The invention comes into consideration particularly for small reactors.