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")
technology started to be used increasingly in machine and plant engineering, in mobile machinery, in motor vehicles, in shipping as well as in aerospace. It was used to automate work processes, to simplify machine [...] glossary "Fluid technology from A to Z"), the 1st edition of which was published in 1989 by Vereinigte Fachverlage in Mainz, Hans Ebertshäuser made an important contribution to defining and explaining the terms [...] authors at HAWE Hydraulik SE, Munich to provide a helpful reference work for fluid technology. The new edition will no longer be published as a printed book, but as an online version in German and English on
Linearisation
transfer element with a non-linear characteristic curve is supplemented to such a degree by the addition of further transfer elements that a new transfer element emerges with an overall linear characteristic curve [...] and on the curvature of the curve ( Figure L 20 ). Of a function : Non-linear functions are tending to be supplanted — particularly for calculations within a specific interval — by linear functions (or [...] shown in ( Figure L 21 ), with the linearisation of a displacement transducer by means of two coils, S1 and S2, in a regenerative circuit.
Hydraulic motor
speed. Neither is dependent on the other: the rotation speed n 2 is only dependent on the flow rate Q 1 introduced and the displacement V 2: while the torque M 2 is determined by the load pressure p L and [...] and the displacement V 2: In general, all pumps (with the exception of valve-controlled pumps) can now also be used as high-speed hydraulic motors. In addition, there is also a range of special designs such
Rotary flow divider
in terms of amounts and can result in improved accuracy (approx. 1-1.5% leakage losses). Toothed wheel flow dividers are made for up to six subflows. Alternative: Flow dividers , Multi-circuit pumps [...] pistons, whose shafts are rigidly connected to one another ( Figure R 36 ). Rotary flow dividers have the advantage over flow divider valves that they work without inherent throttle losses, that the subflows
Slow speed high torque motor
Hydraulic motor designed to run smoothly at very low rotation speeds without any need for transmission. The term slow speed high torque motor is not strictly defined, but it is restricted to a rotation speed range [...] range not exceeding 1 to 150—250 rpm (although this does not mean that controlled "high speed motors" cannot operate in this range too). Based on this definition, slow speed high torque motors are always [...] ed or multi-stroke hydrostatic motors ) which deliver a torque level in keeping with the speed (up to 100,000 Nm and more). Slow speed high torque motors, despite their relatively large size, are associated
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 [...] damping pulsations and pressure surges . As the hoses also have to work even under high pressures, they are rarely used in hydraulic systems without reinforcement linings in the form of textile braiding, steel [...] DIN 20 024 Hoses and hose line testing in fluid technology Safety rules for hydraulic hose lines ZH 1/74, German Federation of Institutions for Statutory Accident Insurance and Prevention
Supply state of hydraulic fluid
the physical state of a new hydraulic fluid . Here is must be noted that even new oil is never absolutely clean, instead on average it corresponds to filter class 7 according to NAS 1638. This means that [...] that in some circumstances oil must be filtered on filling to suit the filtering in the installation.
Accumulator drive
accumulator performs the task of providing energy at power peaks. This can be used to select the flow rate Q 1 of the pump according to the average consumption V N during a working cycle t S: ( accumulator consumption [...] consumers becomes more different. Hydraulic accumulators are to be designed in accordance with DIN 24 552 with a pressure measuring device, safety device to protect against overpressure ( safety valve ) and with [...] can be operated simultaneously from the pressure network with a sufficiently constant pressure and without a reaction. The disadvantage is the power loss, which results when the load pressure p L and accumulator
Sampling control circuit
sampling times. The microcomputer calculates the new correcting variable using the control algorithm , this new correcting variable is then supplied to the holding circuit (mostly D/A converters). This
Nominal viscosity
This used to be +50°C according to DIN 51 502 and has been +40°C for a number of years now according to ISO 3448 (DIN 51 519). It is essential therefore when thinking about nominal viscosity to consider [...] value within the respective viscosity class (e.g. ISO viscosity class 32 ranges from around 29 mm2/s to 35 mm2/s).