Rodless cylinder
are the same size, making it easy to insert the pistons inside a pneumatic spring (Figure K 20) . In this form, the pneumatic cylinder has found favour in a range of new applications. The oldest rodless [...] Cylinder design without a piston rod. As a result, these cylinders have an ideal short installation length just greater than the stroke. With the pistons not having any piston rod, both piston sides are
Velocity measurement
largely immune to interference and is often used these days in with digital signal processing . DC generator To measure angular velocities, essentially DC generators have been used up to now (Figure G 9 a) [...] velocity. The transducers are in practice used for measuring lengths of up to 1 m. If the distance is measured, it is also possible to obtain the velocity from the differentiation of the distance signal. However [...] low rotation speed these devices provide a DC signal that can be evaluated without problems. This voltage is proportional to the rotation speed over a wide tacho rotation speed range. A disadvantage for
Oscilloscope
nib or ink jet to write on graph paper and is suitable for processes of up to around 1 Hz. The light-beam oscilloscope mainly uses UV light, which is deflected by a fine mirror secured to a wire frame. [...] surrounding polygonal mirror allows things to be represented on light-sensitive paper and on a screen. The light-beam oscilloscope is suitable for frequencies of up to around 10 kHz. The cathode ray oscilloscope [...] the beam from a cathode ray tube (Braun tube) in proportion to the input signal and time. With a cathode ray oscilloscope, it is possible to represent things on the screen, set things down on paper and
Kinematical viscosity v
degrees Engler (°E), and then in stokes or centistokes (cSt), but is now given in m 2 /s or mm 2 /s. cSt can be converted as follows: 1 cSt = 1 mm 2 /s
Transfer element
input variables u 1 (t ) ... u p (t ) and output variables v 1 (t ) ... v q (t ), which has a certain transfer function , is called a transfer element (EDIN 19 226 Part 2) ( Figure U 8 ). A transfer element [...] lly to the input signal without delay or other dynamic effects ( Figure U 9 a ); I-element with integrating behaviour. The output signal follows the integral of the input signal over time without other [...] is proportional to the time derivative of the input signal ( c ); There are also elements with time delay . In fluid technology, these are normally: PT1-elements, i.e. P-elements with a 1st order time delay
Plug-in valve, 2-way plug-in valve
result of efforts to simplify controls by breaking down the functions of conventional directional valves into individual functions and combining these functions and making it possible to operate them as [...] required. In this way the function of a 4-direction valve is replaced by four single valves that can now be operated, e.g. also with overlaps ( Figure Z 16 ). This procedure is cost effective because the [...] valves as normally closed or normally open valves ( Figure Z 17 ). The pilot valve required is fitted to this plate ( Figure Z 18 ). For directional valves this is either a normal solenoid valve for switching
Additive (for lubricants)
protection capacity, the resistance to ageing, the wear protection, the viscosity-temperature behaviour, the load-bearing capacity (pressure resistance), and others. (Table A 1) . [...] Chemical additive that changes the existing characteristics of a fluid or adds new characteristics (CETOP RP 100). The natural substance mineral oil is lacking a series of characteristics for its tasks
Stiction of seals
Friction of seals to be overcome at the start of a movement (Figure H 1) . It is dependent on both the form of the seal (preload) and the seal material and on the service life of the seal: during longer [...] longer periods of inactivity, the oil film under the seal is squeezed away allowing dry friction to predominate (Figure H 2) . Stiction of seals is particularly evident during stick-slip movements and during [...] during oscillating movements where the stroke remains within the height of the seal. No new lubricating film can develop during this kind of movement, which means the whole process is affected by dry friction