Primary control
) constant torque, with power increasing to the maximum level ( Figure P 16 ). The resulting adjustment range for rotation speed is as follows: while the torque ratio would be: with the displacement V [...] In a hydrostatic transmission , the pump can be adjusted and the motor is associated with constant displacement . The drive rotation speed is therefore proportional to the flow rate for the pump, i.e.
Measuring instruments
distinction is made between measuring instruments with direct output (measuring instruments performing registration or counting tasks, measuring instruments with a display based on a scale or digits) and measuring [...] measuring instruments involved in some kind of transmission (measuring instruments with indirect output such as measuring amplifiers , and measuring converters ) (VDI 24 2600).
External gear pump
also so noisy that for pressures above 200 bar they are often replaced with internal gear pumps . Pump with two or more gear wheels with teeth on the outside that rotate engaged in each other. As a result [...] most economical hydraulic pumps and are very suitable for simple low-pressure drives. They operate with high reliability and are also robust in operation. They have a large permissible viscosity range and
Hydraulic piloting stage
Another expression for hydrostatic amplifiers associated with servo valves .
Fixed throttle
Throttle with a constant cross section. Opposite: variable throttle .
Digital technology
Collective term for the area of electronic processing and control technology that operates with digital signals with the characteristic that the numerical input signals in turn correspond to numerical output
Transfer element
s, i.e. P-elements with a 1st order time delay, in which the output responds with a time delay with an exponential function ( Figure U 10 a ) and PT2-elements, i.e. P-elements with a 2nd order time delay [...] namely P-element with proportional behaviour. The output signal follows directly proportionally to the input signal without delay or other dynamic effects ( Figure U 9 a ); I-element with integrating behaviour [...] dynamic effects ( b ). D-element with differentiating behaviour. The output signal is proportional to the time derivative of the input signal ( c ); There are also elements with time delay . In fluid technology
Hardness of materials for seals
penetration by another. With materials for seals, this is measured as Shore A. For seals , the chosen degree of hardness would be a Shore A score of between 70 and 90. A material with a Shore A score of 98
HLPD oils
Non-standardised short term used for hydraulic oils with additives designed to provide protection against ageing, corrosion and wear, as well as an additive with emulsifying (dispersing) and detergent properties
Transmitter (unit transducer)
Measuring arrangement, in which a sensor is integrated in a device with a standard electrical with zero and end point comparison elements, which can be adjusted externally and issues a standard output