Compared with the gear coupling, the diaphragm coupling has no relative sliding, no lubrication, sealing, no noise, basically no maintenance, more convenient to manufacture, and can partially replace the gear coupling.Diaphragm couplings have been widely used in developed countries in the world. In practical applications, the intermediate shaft type is generally used to improve the performance of two-axis offset compensation.
　　The diaphragm coupling is composed of several groups of diaphragms (stainless steel thin plate) which are alternately connected with two halves of the coupling with bolts. Each group of diaphragms is made up of several pieces. The diaphragms are divided into rod type and different shapes. The whole piece.
　　During the effective service life of the diaphragm coupling, the wedge-shaped clearance surfaces that are inclined to each other need to be maintained, lubricated, and discharged from the large port into the small port.The two surfaces must have sufficient relative movement speed, the fluid must have sufficient viscosity, and sufficient oil must be supplied.In the maintenance process, the most important thing is to grasp the basic category of hydrodynamic lubrication, which is also the theoretical basis of sliding bearing design.
　　The diaphragm coupling can actively compensate the axial, radial and angular offset caused by the motor, as well as the influence caused by factors such as manufacturing error, installation error, bearing deformation and temperature rise.Diaphragm coupling is a metal elastic element in flexible coupling. The advantages of driven torque transmission, elastic vibration, no noise, and no lubrication are the ideal products to replace gear couplings and general couplings.
　　The diaphragm coupling bolt connection does not need to be threaded on the connecting piece, the use is not restricted by the connecting piece, the structure is simple, and the disassembly and assembly are convenient.Stud bolts can be used in occasions where bolts cannot be used due to structural restrictions, but a compact connection structure is required.The bolt connection does not have a nut and has a smooth exposed surface, but it is not suitable for frequent disassembly and connection to avoid damage to the threaded hole.
　　The core component of the diaphragm coupling can be divided into beam waist type, ring type, combined link type, spokes and multiple modes according to the shape of the diaphragm.According to the working condition of the coupling, we can summarize the force of the coupling into the following four types, and give the planning method of different types of force, taking the eight-hole waist diaphragm as the research about the image.
　　(1) Bending stress caused by angular disassembly error.It can be solved according to the simplification of the figure below.Due to the theoretical error of disassembly in the axial angular direction, the diaphragm is periodically bent and deformed along the axial position. Moreover, it is the main reason that determines the fatigue of the coupling diaphragm.According to the displacement of the bolt hole in the axial position, radial displacement and axial displacement caused by the angular direction.The measurement of the restoring moment H can be obtained by the angle inclination. Generally, the angular displacement of the coupling diaphragm is very small, so the deformation of the diaphragm is a small deformation, which can be analyzed by the small deflection bending theory of the thin plate.
　　(2) Due to the error of axial disassembly, the diaphragm is bent and deformed along the axis.The displacement loads the position of the axis at the local bolt hole, and the radial displacement and axial displacement are active.The space between the two ends at both ends is used to impose a restraint, and a hole is placed to bear the load.In this way, treat it as a statically determinate simply supported mechanism.
　　(3) Centrifugal stress due to inertia during high-speed spinning.