Springs, in which the proportional relationship between the deformation path and the force produced is used for a force comparison in hydraulic controls. A balance is sought between a compressive force p sA s and the spring force. This force comparison serves to maintain a certain distance variable x, e.g. on the valve control spool of a continuously adjustable valve or on the adjustment piston of a hydraulic pump (Figure R 15).
Figure R 15: Example of a control spring (force comparison)