Composition of JM diaphragm coupling

Diaphragm coupling is also called steel flexible coupling and laminated flexible coupling. This kind of coupling mainly realizes vibration reduction and angular, axial and lateral displacement compensation through elastic diaphragm. Diaphragm coupling is mainly composed of metal flexible diaphragm group, left and right half couplings, connecting bolts and other parts. The diaphragm group is composed of a number of stainless steel coated diaphragms, which are alternately fixed to the driving end and the driven end by bolts. The thickness of diaphragm is generally 0.2-0.6mm, and the shape of diaphragm is mainly circular. Wheel width type, connecting rod type, multilateral type and waist-binding type. In practical engineering, double diaphragm coupling with intermediate shaft is often used, which can compensate the parallel misalignment and angular misalignment in the system. The working principle is: when working, the torque is input from the left half coupling, transmitted to the metal diaphragm through the driving torque transmission bolts arranged at intervals along the circumference, and then transmitted to the right half coupling by the diaphragm through the driven bolts for output. It realizes the flexible transmission of the coupling through the elastic deformation of the alloy diaphragm group, and uses the flexibility of the diaphragm to absorb the relative displacement between the input and output shafts, thus compensating the residual misalignment of each connecting part of the transmission shaft system caused by various factors.

The vulnerable parts of diaphragm coupling are diaphragm components. The service life of diaphragm assembly determines the service life and working speed of coupling. Diaphragm couplings produced in China have a corresponding gap with other products in appearance quality and service life. From the actual damaged diaphragm group and theoretical analysis. It can be seen that the damage of diaphragm assembly mainly occurs near the hinge point of diaphragm assembly. This is because when there is angular displacement and axial displacement between the power machine and the working machine, the diaphragm group in the diaphragm coupling connecting the power machine and the working machine will produce additional stress. When the diaphragm coupling is in operation or repeated positive and negative rotation, the diaphragm group bears the action of alternating stress and is prone to fatigue failure.

Torque borne by diaphragm

When the diaphragm coupling transmits torque, the torque is the tensile force generated in the diaphragm along the tangent direction of the bolt distribution circle by driving the driven bolt through the diaphragm element. Torque makes the tensile or compressive stress of the diaphragm change with the working condition, but it can be regarded as constant stress under the working condition.

Forced displacement of diaphragm group

Although the diaphragm assembly transmits great torque when the diaphragm coupling works, it has been proved by practice that the main failure of the diaphragm coupling is not caused by the insufficient torque transmission capacity of the diaphragm assembly, but by the alternating cyclic compound stress on the diaphragm. This compound stress is mostly caused by the additional load caused by the misalignment of the two shafts connected by the diaphragm coupling.

First, the angular deviation of diaphragm coupling

The installation error in the axial direction makes the diaphragm bend and deform periodically along the axial direction, which is the main factor that determines the fatigue life of the diaphragm. The diaphragm coupling is angularly offset, and the large angular offset will make the diaphragm group bear great additional bending moment. For double diaphragm coupling, the angular deviation of diaphragm group is half of that of coupling.

Second, the radial offset of diaphragm coupling

Only the double diaphragm coupling can bear radial deviation, and its ability to bear radial deviation depends on the distance between the two groups of diaphragms.

Third, the axial offset of diaphragm coupling

The axial offset k of diaphragm coupling is influenced by the size of coupling and the number of bolts. The larger the size of coupling, the greater the axial offset it can bear. Axial deviation will cause great stress to the diaphragms. Therefore, for the long service life of the coupling, it is required that the diaphragms should be as close as possible and flat as possible during installation. At the same time, the axial deviation of equipment caused by thermal expansion and cold contraction is taken into account. For the double diaphragm coupling, after the axial offset of the coupling is averaged by the diaphragm groups on both sides of the intermediate body, the axial offset of the diaphragm group is half of that of the diaphragm coupling.