Doc. dr. Franc Majdič, univ. dipl. inž., Univerza v Ljubljani, Fakulteta za strojništvo

Abstract​:
Hydraulic accumulators (HA) are installed in numerous HS mostly to add pressurized hydraulic liquid (HL) in HS to compensate the disproportionate consumption of some working hydraulic components (cylinders and hydraulic motors) during an operating cycle of a machine or production line. Such consumption is often present in large industrial systems of power-control hydraulics (PCH).

When designing such a HS, the required volume of HA (one or more) must be calculated. The project engineer needs basic practical knowledge in the field of HA. In the first part of this paper some equations depending on HA are derived and the final equation that allows calculating the volume of HA is presented.

The second part of the paper deals with a computational example to determine the adequate volume of HA for three different situations involved a HS. It is presented as a hydraulic scheme. The HS consists of four working hydraulic components (three cylinders and a hydraulic motor), corresponding hydraulic valves and all other related components. The influence of different limiting pressures and the type of pump control on the required volume of HA is explicitly shown.

The subject of this and the previous paper gives a hydraulic designer appropriate knowledge to define suitable HA for a hydraulic system.

Keywords:
Power-control hydraulics (PCH), hydraulic system (HS), hydraulic accumulator (HA), hydraulic component, hydraulic liquid (HL), boundary pressures, equation.