Method for operating a hydraulic system of an industrial truck having a plurality of hydraulic pumps, and industrial truck

An industrial truck comprising:

• a controller comprising hardware, the controller being configured to:
• provide a delivered volumetric flow of a hydraulic medium for moving at least one hydraulic cylinder by a hydraulic device which has at least one hydraulic pump and which at a minimum rotational speed of the at least one hydraulic pump provides a minimum delivered volumetric flow of a hydraulic medium,
• wherein when reaching a predetermined delivered volumetric flow which is greater than the minimum delivered volumetric flow of the hydraulic device, connect a further hydraulic pump having a minimum rotational speed for increasing the delivered volumetric flow of the hydraulic medium when the rotational speed of the at least one hydraulic pump of the hydraulic device is equal to or greater than the minimum rotational speed of the at least one hydraulic pump of the hydraulic device and the rotational speed of the further hydraulic pump is equal to or greater than the minimum rotational speed of the further hydraulic pump.

A processing apparatus comprising:

• a controller comprising hardware, the controller being configured to:
• provide a delivered volumetric flow of a hydraulic medium for moving at least one hydraulic cylinder by a hydraulic device which has at least one hydraulic pump and which at a minimum rotational speed of the at least one hydraulic pump provides a minimum delivered volumetric flow of a hydraulic medium,
• wherein when reaching a predetermined delivered volumetric flow which is greater than the minimum delivered volumetric flow of the hydraulic device, connect a further hydraulic pump having a minimum rotational speed for increasing the delivered volumetric flow of the hydraulic medium when the rotational speed of the at least one hydraulic pump of the hydraulic device is equal to or greater than the minimum rotational speed of the at least one hydraulic pump of the hydraulic device and the rotational speed of the further hydraulic pump is equal to or greater than the minimum rotational speed of the further hydraulic pump.