The load category of the coupling in the transmission system is the basic basis for selecting the type of coupling.For working loads with large changes in shock, vibration and torque, flexible couplings with elastic elements, that is, elastic couplings, should be selected to buffer, reduce vibration, compensate for axis deviation, and improve the performance of the transmission system.The torque during frequent starting, forward and reverse rotation, and braking is several times the torque during normal and stable operation. It is overload work, which will inevitably shorten the service life of the elastic element of the diaphragm coupling. The coupling only allows short-term overload, generally The short-term overload shall not exceed 2-3 times of the nominal torque.Between the coupling power machine and the working machine, the main and driven ends are connected through one or several couplings of different varieties or different types and specifications to form a shaft transmission system.In mechanical transmission, power machines are nothing more than electric motors, internal combustion engines and steam turbines.Due to the different working principles and structures of the power machines, their mechanical properties are quite different. Some run smoothly, and some run with shocks, which have unequal effects on the transmission system.According to the mechanical characteristics of the power machine, the power machine is divided into four categories: electric motors and turbines, four-cylinder and more than four-cylinder internal combustion engines, two-cylinder internal combustion engines, and single-cylinder internal combustion engines.

　　①当联轴器内径公差带与轴公差带构成配合时，在一般基孔制属过渡配合的公差代号将变为过盈配合，如k5、k6、m5、m6、n6等，但过盈量不大;当轴承内径公差代与h5、h6、g5、g6等构成配合时，不在是间隙而成为过盈配合。

　　②The outer diameter tolerance zone of the coupling is also a special tolerance zone because the tolerance value is different from the general reference shaft. In most cases, the outer ring is fixed in the housing hole, and some coupling components require adjustments. , Its coordination should not be too tight, and often cooperate with H6, H7, J6, J7, Js6, Js7, etc.

　　For the vertical joint surface of the coupling parts, the round run-out tolerance of the rotating end face is 6, and the round run-out tolerance of the other end face is 7; the radial run-out tolerance of the mating surface and the guide surface is 6; other cylindrical surfaces The radial circle runout tolerance is 7; the coaxiality tolerance of the mating surface and guide surface rotation is 5.The coupling seller shall state the required bolt tightening torque value. The vertical flange of the hub and the spacer shall adopt bolts for reaming holes and self-locking nuts, and the hole size tolerance zone is H8.The bolts should be limited to a certain quality range to avoid adverse effects on the balance of the coupling during interchange.When the buyer requires electrical insulation of the coupling, the coupling with spacer should be selected, and there should be electrical insulation on the flange joint surface and the bolt position.

　　The design of the coupling considers the axial displacement between the two to be connected, and its value should be greater than 6mm.When the coupling is installed, the necessary compensation amount should be reserved in the direction of thermal expansion.The structure of the gear coupling without spacer sleeve should allow the gear sleeve to make an appropriate amount of axial movement, so that the internal and external teeth can be separated from the mode, so that the working condition of the gear teeth and the equipment need not be disassembled during maintenance.The structure of the coupling should ensure that all parts are aligned.The mating inner and outer teeth should be centered by the tooth top.In order to reduce potential unbalance, the tooth circumferential backlash