Piston
medium acts and thereby generates a compressive force. F K = p 1 · A K — p 2 · A R Since friction occurs during the piston movement (particularly at the seals ), the force given off is smaller (≤ nominal force [...] piston is set down on the diameter of the piston rod (area A St). This results in an annular area A R, which is also the return area for differential cylinders ( ratio of piston areas α). With single-acting
Pressure-flow (p-Q) control of a pump
Controller combination in which the setpoint Q for the flow rate controller and the setpoint p for the pressure controller are pre-defined electrically on proportional valves. In this way the performance [...] system and in this way the losses with closed loads significantly reduced by operating the flow rate at a low pressure, the so-called standby pressure (approx. 15...20 bar) (Figure D 74) .
Surface roughness
or R max — does not say anything about whether the profile is "open" — which is not good for seals ( Figure O 1 a ) — or "closed" — and therefore good for seals ( b ) — the R t value for the profile must [...] an R a of 0.5 to 1.5 μm is often used. However, in order to minimise the debris from seals on moving surfaces, the R a for these must not exceed 0.25 μm. However, since the R a value — just like R t or
Control card
Printed circuit board (PCB) with electronic controller - at European manufacturers mostly in the eurocard format - that is used to control a proportional valve or servo valve. The control card is mostly
Labyrinth seal
by the contour of the gap assuming a meandering or zigzag pattern ( Figure L 1 ). Labyrinth seals — mainly filled with grease — are used in hydraulics to protect roller bearings in heavily contaminated
Primary control
adjusted displacement volume. This would result - at constant pressure - in a (theoretically) constant torque, with power increasing to the maximum level ( Figure P 16 ). The resulting adjustment range for rotation [...] rotation speed is as follows: while the torque ratio would be: with the displacement V 2 remaining constant (see also secondary control ).
Power transmission
Transmission of power - hydraulic ( flow rate · pressure ) - mechanical (torque · angular speed) - electrical (current · voltage) from the generating part of a system (e.g. electric motor, hydraulic pump)
Creeping motion
This control process — known as creeping motion — uses an additional pedal (creep pedal), which controls the scale of the reduction in velocity by pivoting back the traction drive pump at full rotation speed [...] required in a mobile hydraulic drive system — with a specific (mechanical or electronic) relationship between the accelerator pedal position and the movement velocity — where a particular movement (e.g. movement
Cleanliness level
specified for 5μm and 15μm. For example, the marking 13/10 shows that between 4,000 and 8,000 parts more than 5μm and between 500 and 1,000 parts more than 15 μm can be contained in 100 ml of liquid ( contamination [...] present in hydraulic fluid . Purity classes are stated either in filter classes according to NAS 1638 — which specifies the permitted particle numbers in five particle size areas –– or in purity classes according
Output unit
Function unit within a digital computer system with which the system outputs data - e.g. calculated results - to the exterior (EDIN 44 300 Part 5).