Darcy friction factor λ
factor between the pressure loss and dynamic pressure related to the circular cross section, when flowing through a straight of length 1 and diameter d. λ depends on the Reynolds number and the surface
Force density
comparative investigations, since it makes it possible to draw conclusions regarding the compactness of various types of drives offering the same power ( Table K 1 ).
Solubility of gas in a hydraulic fluid
The saturation state characterised with this law does not of course always have to be reached. At atmospheric pressure 1 l of oil contains approx. 90 cm3 of air, at 100 bar however as much as 9 l. Attention: [...] dissolving certain amounts of gases. In mineral oil this ability increases linearly with pressure up to approx. 300 bar. Dalton's law states: V G = dissolved gas volume at the reference pressure V öl = volume
Fieldbus
between the devices connected to it (Figure F 8) . The devices are primarily sensors, actuators, valves and process-related components, as well as control terminals and interfaces to other bus systems. These [...] communication that generally uses the 7-layer ISO/OSI architecture model is limited in fieldbus to layer 1 (physical layer), layer 2 (data link layer) and layer 7 (application layer). As the hardware for [...] ensure signal transmission with the correct timing, a high level of immunity to interference and flexibility in relation to the number of bus users, speed and type of data transmitted. These days in industrial
Calculating the sound power
45 635 Part 1 framework ( Figure S 11 ) and DIN EN 23 741. The sound power of a machine calculated under measurement conditions does not allow for a final statement to be made with regard to the noise emissions [...] for determining the sound power is to measure the intensity of the noise in a measured area around the object. In doing so, environmental influences are eliminated to a certain extent. The calculation of [...] The various methods of noise measurement. are available to determine the sound power. The calculation of the sound power may be performed by measuring the sound pressure in a soundproof room or in a free
Inductive pressure sensors
1. "Genuine" inductive pressure sensors operate in accordance with the principle of inductive position measurement whereby the core of the coil is connected to a diaphragm whose deflection it measures
Thin foil element
switching and sealing element that, as a consequence of the very low mass, permits switching times of 0.2 to 1 ms (Figure F 33) . Even though the thin foil element is switched by a static pressure signal or d
Neutralisation number
acid content of a mineral oil . It indicates how many mg of potassium hydroxide are needed to neutralise in 1 g of oil the free acids generated during operation. Since the acid content is dependent on
Heat balance in hydraulic systems
motors): Another part is radiated to the surrounding environment: The oil container is primarily involved in this. Depending on the ventilation of the surface A, k = 5.8–11.6 W/m2K can be used if the temperature [...] beneath the operating temperature T B, no further measures are necessary ( Figure W 1 , curve I). The same applies to the case that T B only reaches t B after the operating time given a largely rising curve
Position measurement process
measurement (with potentiometer) is commonly used for lengths of up to around 1 m and inductive position measurement is used for lengths of up to around 500 mm. In contrast capacitive position measurement is