www.jbj.co.uk/couplings.html#flender 3 #DriveLineHarmony Technical Information Mechanical Power Transmission Couplings Half parallel key standard Eccentricity of centre of gravity of coupling ecoupl Flender balancing quality Order code Full parallel key standard better than 16 μm special balancing on request Balancing Today it is usual for themotor rotor, as well as the gear unit and drivenmachine shaft, to be balanced in accordance with the half parallel key standard. The balancing standard normally applied today. Before balancing, a half parallel key is inserted in the shaft and another in the coupling hub. Alternatively, balancing can be carried out before cutting the keyway. The balanced parts must be marked with an "H". This marking can be dispensed with if it is absolutely clear which parallel key standard has been applied. Flender Balancing Standard Balancing standard in accordance with DIN ISO 21940-32 Besides the required balance quality, it is necessary to set standards which define how the mass of the parallel key is to be taken into consideration when balancing. In the past, motor rotors have frequently been balanced in accordance with the full parallel key standard. The "appropriate" balance condition of the coupling hub was described as "balancing with open keyway" or "balancing after keyseating". No parallel key standard e = 9550 • ― perm e ≤ e coupl perm The balancing quality level, together with the operating speed, results in the maximum permissible eccentricity of the center of gravity of the coupling or the coupling subassembly. In the Flender article number the balancing quality can be preset with the help of the order code. Additionally, also the balance quality level to DIN ISO21940 can be preset together with the operating speed belonging to it, which then be taken as priority. The parallel key is inserted in the shaft keyway, then balancing is carried out. The coupling hub must be balanced without parallel key after keyseating. Marking of shaft and hub with "F" (for "full"). Balancing of shaft and coupling hub after key seating, but without parallel key. Not used in practice. Marking of shaft and hub with "N" (for "no"). The length of the parallel key is determined by the shaft keyway. Coupling hubs may be designed considerably shorter than the shaft. Permitted eccentricity of center of gravity e in μm perm Balance quality levels The so-called quality level G to DIN ISO 21940 indicates a range of permitted residual imbalance from zero up to an upper limit. Applications can be grouped on the basis of similarity analysis. For many applications a coupling balance quality of G 16 is sufficient. On drives susceptible to vibration the balance quality should be G6.3. Only in special cases is a better balance quality required. To prevent imbalance forces caused by projecting parallel key factors when balancing in accordance with the half parallel key standard in the case of applications with high balancing quality requirements, grooved spacer rings can be fitted or stepped parallel keys used. Eccentricity of center of gravity of coupling e in μm coupl Balancing quality level G inmm/s Coupling speed n in rpm maximum100 μm standard balancing without specification maximum40 μm fine balancing W02 maximum16 μm micro-balancing W03 G n
RkJQdWJsaXNoZXIy NzQyNjQ=