The requirements for the end distance deviation of diaphragm couplings are based on the formula of the additional stress caused by the relative displacement of the two axes. In the case of axial installation distance deviation, when the coupling bolt is tightened, the diaphragm will produce corresponding force. At the time of installation, the two situations exist at the same time, which will produce superposition of force.

In addition, the axial displacement of the equipment may accelerate the damage of the diaphragm, so the deviation of the coupling installation can not be too large, too large will damage the diaphragm. When the diaphragm coupling leaves the factory, it is generally strictly implemented that the radial runout is less than or equal to 0.15mm and the end runout is less than or equal to 0.1mm. This is mainly considered from the service life of the coupling.

The actual installation error of the axis Angle will cause periodic deformation of the diaphragm along the axis direction, which is also the main factor determining the fatigue life of the diaphragm. The force generated by one side torque is evenly distributed on the four separate bolt holes, and the force acts on the side of the middle bolt hole circumferentially, resulting in the fixed radial displacement and axial displacement in the middle.

Generally speaking, the radial displacement, circumferential displacement and axial displacement of the fixed intermediate bolt hole have no other loads around them. The size of the additional stress is related to the angular displacement of the two axes and the relative axial displacement of the two axes, as well as the number of bolts of the coupling, the thickness of the diaphragm and the distribution radius of the coupling bolts. Therefore, it is suggested that the specific alignment standard should be carried out according to the design requirements of the equipment.