Special cylinder
series-production cylinders can be used. This includes, for example, press cylinders or cylinders with an adjustable stop.
HL oils
Term used for hydraulic oils with anti-ageing and corrosion-protection properties for systems subjected to a high thermal load. Viscosity index 95 to 105. (requirement standard DIN 51 524, Part 1).
Hydrostatic servo drive
Collective term for hydraulic cylinders and hydraulic motors . Given the low losses associated with the drive, both have very low levels of damping (D H = 0.05 to 0.2).
Non-linear control system
whereby the control algorithm is associated with non-linear behaviour, i.e. the input and output for the controller are linked to each other by a non-linear characteristic curve or function.
Control unit
programmed cycle of all control functions in cyclical sequence and can be connected via a bus line with all inputs, outputs, functional units and the program memory.
Three position valve
Valve with three switching positions (e.g. forward-stop-backward). The number of positions is stated after the number of ports, e.g. 4/3 directional valve: 4 ports, 3 switching positions.
Constant pump
Hydraulic pump with constant geometric displacement V 1 for each revolution and therefore a constant delivery flow Q 1 at constant drive speed n 1: Q 1 = V 1 · n 1.
Adhesion property of hydraulic fluids
plain bearings and under seals , it must have sufficient wetting ability. This is generally the case with HLPD oils .
Continuously adjustable pressure valve
Valve with a proportional connection between the input signal and pressure in the working lines (consumer ports). This includes construction designs of proportional pressure-limiting valves and pressure
Blow-by effect
"Blowing past" a piston seal. With large pressure gradients it can occur that the seal is not pressed against the sealing surface, instead it is pressed into the grove (Figure B 21) .