Parallel circuit / connected in parallel
system ). When cylinders are arranged in a parallel circuit, it is important to ensure the element with the lowest resistance (load, friction) to overcome starts the movement ( Figure P 2 ). The next actuator
Signal flow diagram
contexts (e.g. circuits for addition points ( Figure S 58 ). Each signal is shown by a line of action with an arrow at the top (DIN 19 226). The functional relationship may be illustrated by descriptive equations
Reference variable
the exterior and that the output variable of the control or feedback control is intended to follow with the stipulated dependency (DIN 19 226). Based on this definition, the reference variable is the same
Volumetric losses
Arise with all displacement machines as the sum of the leaked oil and compression losses. The pressurised chambers in the devices are sealed off from moving components by mating surfaces and rods. There
Relative delivery fluctuation δ
design of the pump and the number of displacement elements. In addition, in the case of piston pumps with an even number of pistons, δ is around twice as high as in the case of an uneven number. The kinematic
Flame-resistant hydraulic fluids
) of aqueous solutions ( HFC pressure fluids ) and water-free, synthetic fluids in the HFD group . With the exception of the HFA group –– which is practically incombustible –– all of the others are only
Beta value (β value)
is a ratio that is defined by the number of particles before and after passing through the filter with a specific pressure drop (Figure B 13) : Therefore at β x = 1 no particles are removed; 50 % of the
Air in oil
rate of dissolving, air bubbles remain in oil for longer still, even when pressure increases again, with the consequences outlined above. During assembly work, air infiltrates the circuit at places in the
Hoses
Flexible lines to supply moved components with liquid or gaseous media. Hoses in hydraulic systems, alongside transporting hydraulic fluid to moved consumers ( cylinders , motors ), often have the task
Foreword to the online edition of the O+P-Fachlexikon "Fluidtechnik von A bis Z" (O+P technical glossary "Fluid technology from A to Z")
themselves from competitors. This situation marked the terminology in fluid technology for a long time. With the O+P-Fachlexikon "Fluidtechnik von A bis Z" (O+P technical glossary "Fluid technology from A to [...] and refinement of terms and definitions. For this reason in 1995 there was a 2nd revised edition with the joint authorship of Hans Ebertshäuser (who died in 1992) and Siegfried Helduser. Here in particular