Gear pump flow meter
used for flow rate measurement (flow measurement) according to the displacement principle, which works like a geared motor . The flow rate to be measured rotates the pair of gears. This movement of the [...] The flow rate is then the product of the chamber volume, number of gears and rotation speed (Figure Z 1). The accuracy of the gear pump flow meter depends on the leakage in the gears; it is around ±0.5 %
Speed ratio
The speed ratio of a hydrostatic transmission is defined by the ratio of the pump speed n 1 to the motor speed n 2:
Buckling of rams
(Figure K 12) . This value is referred to as the buckling force F K. Cylinders with a large stroke and/or a thin piston road should undergo further calculations with regard to possible buckling. Euler's formula [...] formula applies in this regard to cylinders arranged vertically and to the application of centric forces. where l = the smallest axial planar moment of inertia s = free buckling length (see Figure K 12) S [...] S K = safety factor (safety in terms of buckling) In addition to the basic scenario (scenario 1), another three buckling scenarios are possible in this context (Figure K 12). Mounting scenario 2 applies
Tachogenerator
current generated in this way is proportional to the rotation speed over a wide range ( Figure T 1 ). Advantage: Can be used at low rotation speeds. Disadvantage: The collector with brushes requires regular [...] Device used to measure angular rotation speed. Tachogenerators can work as DC or AC generators. DC generator : The most commonly used process, in which a rotor turns in a magnetic field. The direct current [...] doing so, a sinusoidal output voltage is induced in the stator winding, whose amplitude is proportional to the rotation speed ( Figure T 2 ). Advantage: Low maintenance Disadvantage: Measurement voltage must
Cleanliness level
stated either in filter classes according to NAS 1638 — which specifies the permitted particle numbers in five particle size areas –– or in purity classes according to ISO 4406, where the permitted particle [...] for 5μm and 15μm. For example, the marking 13/10 shows that between 4,000 and 8,000 parts more than 5μm and between 500 and 1,000 parts more than 15 μm can be contained in 100 ml of liquid ( contamination
Indexing ratios when using flow dividers
oil flow is multiplied by the indexing ratio, therefore in practical use, an indexing ratio of up to 4:1 is still reasonable.
Hamming distance d
the Hamming distance is equal to the number of bits (minimum) where they differ, DIN 44 300. Example: some dual system or BCD code strings have a Hamming distance of d = 1; single errors producing a signal [...] signal change at just one binary position will cause them to look like another code word (Figure) . A code string with a Hamming distance of d = 2 offers greater transmission security, since single errors [...] errors can be detected and corrected. Only double errors will cause something to look like another code word.
Nominal width
1. Term previously used instead of " nominal size " to indicate a device size. 2. Standardised numerical variables with which the inside diameter of pipes is compared. The nominal width for pipes is defined
Stabilised hydraulic oils
Modified HLPD oils that only take on (hold) a water content of 1 to 2%, but separate larger water quantities –– like any normal mineral oil . The stabilised hydraulic oils therefore only slightly reduce
Friction conditions
which can be attributed to characteristic mechanisms of action. A distinction is made between three different friction conditions ( Figure R 23 ): Solid dry friction (a) arises due to adhesion and deformation [...] > 0.5; Mixed friction (b) occurs in the transitional area between solid and liquid friction, μ = 0.1 to 0.2. Mixed friction is characterised by the simultaneous presence of areas with lubricating film and [...] increases. Liquid friction (c) arises due to the build-up of a stable lubricating film between the sliding bodies. The dynamic pressure created in the wedge-shaped gap due to the viscosity of the lubricant separates