Structure and stiffness characteristics of diaphragm coupling

　　With the rapid development of modern industrial technology, the research on high-speed and high-power rotating machinery has received extensive attention, especially in the dynamics of complex rotor systems.The connection problem between the rotor spans has also been widely noticed, which has led to the continuous emergence of various new high-performance flexible couplings. The relative displacement of the shaft coupling part caused by various factors often requires the use of flexible couplings. compensate.Metal diaphragm flexible coupling (diaphragm coupling) is a new type of flexible coupling device.
　　Diaphragm couplings have many advantages, such as high rigidity in the torsional direction, high torque transmission, and great deflection in the axial and angular directions.It is a flexible coupling that mainly relies on the three-dimensional deformation of the metal diaphragm material to absorb various (including axial, lateral, and angular) deviations between the transmission shafts, and has the function of absorbing and damping vibration, especially suitable for high-speed Heavy duty occasions.　　
　　1. Diaphragm coupling structure
　　Diaphragm coupling Among them, the diaphragm is the key component of the coupling, through which torque and movement are transmitted.It is made up of a large number of thin high-strength alloy sheets, and the thickness of the diaphragm can be as thin as 0mm.The main shapes are spoke type, ring type, connecting rod type, polygon type and waist type.
　　The diaphragm used is a beam waist type, because it has the advantages of close to equal strength, good flexibility, low stress around the bolt hole, and small centrifugal force.The working principle is that the torque is input from the semi-coupling of the driving end, and the torque is transmitted to the diaphragm group through the main torsion high-strength bolts arranged at intervals along the circumference. After passing through the intermediate shaft section, the torque is transmitted from the diaphragm group to the driven end again. Half coupling output.
　　2. The stiffness characteristics of the diaphragm coupling
　　A more in-depth study has been made on the vibration characteristics of the diaphragm coupling.The change of the axial elastic stiffness of the diaphragm group is non-linear, that is, with the change of the axial displacement, the axial elastic stiffness is not proportional to the axial deformation.The axial stiffness K1 and the lateral stiffness K2 are shown in equations (1) and (2) respectively.
　　K1 =4 .3EkzbF(u)h3 (φ0 R)3 (1)
　　K2 =414Ebh3 zk πRφ30L2c (2)
　　Where k is the number of bolts on the half coupling, z is the number of diaphragms in each group, R is the radius of the connecting bolts, b is the width of the diaphragm, E is the elastic modulus of the diaphragm, φ0 = (π k )-( 0d R) is the included angle of the elastic part of the diaphragm between two adjacent bolts, d is the diameter of the fastening washer, F(u) is a function of u = 8 (δ h)1, where δ is the membrane The axial displacement of the diaphragm, h is the thickness of the diaphragm, and Lc is the distance between the center lines of each group of diaphragms.