Noise level L W
an acoustic radiator in relation to a specific output W o of 1 pW. The sound power level is therefore a machine-specific variable, which is used by machine operators to calculate the noise level for any
Controller types
According to DIN 19 225, controllers are divided according to their tasks and properties. Designation according to tasks distinguishes between the type of the controlled variable , such as the location [...] value, sequence, master controllers, amongst others). For designation according to properties, a distinction is made by order: 1st, 2nd order system, etc., by signal form: analogue or digital controller, by
Accumulator consumption diagram
volume V N). To assess the flow requirements per working cycle, it is practical to create an accumulator consumption diagram ( Figure S 69 ). The pump must be selected with a certain size in order to replace [...] replace the removed usable volume before the end of the working cycle: The factor k (approx. 1.25) serves to relieve the burden on the pump during part of the working cycle.
Hydropneumatic accumulator
increasing withdrawal of the usable volume in accordance with the ratio of gas capacity to oil volume (Figure G 1) . Alternative: spring accumulator , weight accumulator . [...] Hydraulic accumulator that uses a gas as the medium for applying a load to the hydraulic fluid (air for accumulators for water hydraulics , nitrogen for oil accumulators). As a consequence of the gas cushion
SAE flange
The SAE flange can be used as a two-part flange to connect pipelines to non-split counterfaces or as a one-part flange (SAE j 518c) to connect pipelines to one another. The mounting dimensions of the SAE [...] SAE j 518 ( Figure S 1 ) are the most commonly used flange connections . The American SAE norm specifies two pressure stages 3,000/6,000 PSI (210/420 bar), nominal widths of 15 to 50 and fastening screws
Response sensitivity
five-stage digital valve has 25—1 = 31 steps between zero and maximum, i.e. a resolution of 3 %. The response sensitivity of a proportional valve from 0.2 to 0.3 % corresponds to 200 to 500 steps between zero and [...] Change in the input signal that is necessary to generate a measurable change in the output signal, if the input signal is changed from a static point in the same direction in which the static point was [...] and maximum. If the change is opposite to the direction of movement the term reversal error is used.
Natural frequency fo
frequency of a second order delay element designed to be damping-free, If a system capable of oscillation such as a spring-mass system is prompted to oscillate as a result of sinusoidal external excitation [...] and the amplitude will be 1/2 the initial amplitude where f = 0. With a high response proportional valve, the natural frequency for the valve should be much higher (around two to three times higher) than [...] than the natural frequency for the hydraulic actuator to ensure the system as a whole can deliver good dynamic performance.
Pressure ratio
final pressure to the absolute inlet pressure on a compressor. The pressure ratio on a multi-stage compressor is given by the ratio of the absolute inlet pressure of the 1st stage in relation to the absolute
Hydrostatic traction drive
form of control is used (e.g. automatic control), the hydrostatic traction drive will be able to adjust to the power curves of the combustion engine and thereby fully exploit its torque. This means that [...] torque is available, even at a low motor speed (= lowest accelerator pedal setting f 1) (Figure H 28) . This also applies to the braking torque. Using a limit load control prevents the combustion engine becoming
Parallel circuit / connected in parallel
connected to each other. When hydraulic resistances are arranged in a parallel circuit, the flow rate in the individual branches is divided up in inverse proportion to the resistance ( Figure P 1 ). The [...] When cylinders are arranged in a parallel circuit, it is important to ensure the element with the lowest resistance (load, friction) to overcome starts the movement ( Figure P 2 ). The next actuator only [...] arrangement of devices in a parallel circuit, also referred to as redundancy, improves reliability but involves higher costs. When sub-circuits are arranged in a parallel circuit, several loads ( cylinders