Pre-charged oil tank
The pre-load of the container may also be a suitable measure to improve the suction behaviour of pumps.
Gap seals
also non-wearing – when using clean oil. In hydraulics, the axial gaps are predominant. In piston pumps, radial gaps also occur.
Constant flow system
losses are ignored. Constant flow systems in an open circuit are therefore always fitted with constant pumps (in a closed circuit, with a variable pump ) and can only operate one load at a time ( Figure K 30
Variable pump, variable motor
changed. For design-based reasons, this is only possible for vane and piston constructions. Variable pumps can be adjusted from the maximum to zero or through zero to the maximum negative ( reversing pump
Positive displacement principle
port) to the outlet (pressure connection). As there is no direct link between the two connections, pumps that operate in accordance with the positive displacement principle ( Displacement machine (displacement
Rotary flow divider
Toothed wheel flow dividers are made for up to six subflows. Alternative: Flow dividers , Multi-circuit pumps
Intake characteristic
Characterises the varying capability of displacement pumps to draw the required flow rate from a tank. Apart from the type of pump, the intake characteristic is determined by the magnitude of the vacuum
Surface foam
can have a disruptive effect within the hydraulic system. Since surface foam causes cavitation in pumps, it must not be drawn in. This can be ensured by means of various design features in the container:
Hydraulic drive systems
comprises the generative section in which the hydraulic energy is in general produced by hydraulic pumps, the conducting section, comprising and fluid power control devices (control elements) and the motor
Reversing pump
the pressure line and vice versa without changing the rotating direction ( Figure R 27 ). Reversing pumps are used in closed circuits, where they allow the rotating direction of the motor to be changed without