Considerations on switching methods for hydraulic pumps are necessary if several pumps are used in a hydraulic system. A distinction is then made between (Figure S 17):
two-circuit or multi-circuit switches:
Each pump supplies its own circuit.
Several pumps work together for a single consumer. This may be caused by a fixed circuit connection or temporary interconnection.
A special type of parallel circuit is the combination of Low-pressure and high-pressure pumps (e.g. for rapid traverse circuits).
Pump 1 leads to pump 2. This circuit is used to improve the filling of a high-pressure pump or to reach a higher output pressure at pump 2 (e.g. in the case of some internal gear pumps to reach 300 bar).
Figure S 17: Switching methods for hydraulic pumps