The coupling diaphragm is widely used in shaft transmission systems of various mechanical devices, such as water pumps (especially high-power and chemical pumps), fans, compressors, hydraulic machinery, oil equipment, printing machinery, textile machinery, chemical machinery, mining equipment, metallurgical equipment, aviation (helicopters), naval high-speed power transmission systems, steam turbines, reciprocating engine power transmission systems, tracked vehicles, as well as high-speed, high-power mechanical transmission systems of power generation units. After dynamic balancing, their application in high-speed shaft systems has become quite common.

The potential unbalance factors of the coupling diaphragm assembly are explained in the following items. This standard provides the AGMA standard method for calculating the total impact of these factors on the coupling unbalance, as seen in the calculation examples. Balance correction tolerance - The balance correction tolerance is the large unbalance that does not require further correction. The error of the balancing machine is mainly caused by the following factors: the sensitivity of all machinery and equipment except for the drive; only considering the error of the driving machine. The unbalance of the shaft assembly is due to the comprehensive unbalance of all parts on the shaft assembly, including the shaft, sleeve, half coupling, clamping device, key, set screw, nut, and bolt, etc. The eccentricity of the installation surface of the shaft assembly refers to the eccentricity of the surface of the shaft assembly with the coupling assembly or parts, relative to the rotation axis of the balancing operation. The eccentricity of the coupling alignment surface refers to the eccentricity of any alignment surface after the balancing operation and reassembly, which allows the axis of another coupling part or assembly to undergo a corresponding radial displacement. This eccentricity is caused by the following factors: due to the coaxiality of the parts themselves, and due to the change in alignment surface after balancing. The clearance of the coupling alignment surface refers to the radial displacement allowed for the axis of the coupling parts or assembly after reinstallation following the balancing operation. When the coupling is considered as an assembly for balancing, the potential radial displacement is equal to the entire radial clearance. When the coupling is balanced as a single part, the potential radial displacement is equal to half of the radial clearance.

The coupling diaphragm has a characteristic similar to that of a bellows coupling, as the methods of torque transmission for couplings are generally quite similar. The diaphragm itself is very thin, making it easy to bend when subjected to relative displacement loads, thus capable of accommodating up to 1.5 degrees of deviation while generating lower bearing loads in servo systems. Diaphragm couplings are commonly used in servo systems, offering good torque rigidity but slightly less than bellows couplings. On the other hand, diaphragm couplings are very delicate and can be easily damaged if misused or not properly installed. Ensuring that deviations remain within the normal operating range of the coupling is very important. Choosing the right coupling is a crucial step in utilizing couplings effectively, and it should be considered during the design phase.

Additionally, compared to gear-type couplings, shaft couplings with diaphragms have no relative sliding, do not require lubrication or sealing, are noiseless, require minimal maintenance, are easy to manufacture, and can partially replace gear-type couplings. Diaphragm couplings are widely used in the industrialized world and in China, where they have been established as a mechanical industry standard. Recently, this standard has been revised to the new industry standard: JB/T 9147-1999 (replacing ZB/T J19022-90), detailing the relationships between the torques of shaft couplings.

Regarding the impact of coupling diaphragms on equipment balance, that's all for today's introduction. There's still much to learn about this coupling diaphragm product. This requires us to observe and think, communicate more in our daily use, gradually accumulate industry experience, and deepen our understanding of the coupling diaphragm product.