Pressure pulse
Brief pressure rise and pressure drop or vice versa (DIN 24 312).
Limit monitor
Compares the value of an input variable with a limit. If this limit is exceeded or dropped below, the limit signal changes (DIN 19 237).
Negative-pulse control
Not used very often now, because switching may also occur in the event of an unintentional pressure drop.
Release valve
allowing the compression volume to escape in a controlled manner until the pressure in the chamber has dropped to a specific value (see Energy content of hydraulic fluid ).
Flow resistance
friction must overcome when flowing through and valves . It is noticeable in the form of a pressure drop ( pressure loss ). The flow resistance comprises frictional losses and the form-related losses (Figure
Suction filtering
ideal, as then the pump is also used optimally. In reality, however, as the dirt absorbing capacity drops, there is a risk of cavitation in the pump. Therefore, suction filters generally have a relatively
Leakage compensation
Systems featuring leakage compensation ensure the pressure within individual devices does not drop — despite a leakage — by constantly compensating for any oil leaking out. This is achieved, for example
Spring accumulator
excessively large. On the spring accumulator, like on the hydropneumatic accumulator, the pressure drops on drawing the usable volume as a function of the hardness of the spring.
Acceleration feedback
feedback makes possible significantly higher loop gain than P controllers . However, this advantage drops off quickly with increasing damping. Acceleration feedback requires a control element that is as fast
Friction losses
turbulence) and mechanical friction on the moved parts. The friction losses are expressed as a pressure drop or pressure loss .