时间：2014-02-21 19:05　作者：admin　点击： 次

1.When selecting a universal coupling, it should be selected according to the load characteristics, calculated torque, bearing life and working speed.
 
2． 计算转矩由式（1）、式（2）或式（1）、式（3）求出：
　　Tc=KT ………………(1)
　　T=9500Pw/n …………(2)
Or T=7020PH/n ……(3)
　Where:
　　Tc--calculated torque, Nm;
　　T--theoretical torque Nm;
　　Pw--drive power, kW;
　　PH--drive power, horsepower;
　　N--working speed, r/min;
　　K-working condition coefficient.
 3.Under normal circumstances, the universal coupling is selected according to the transmitted torque and bearing life. It is also possible to check only one of the torsion strength or bearing life according to the specific use requirements of the mechanical equipment.
 
　3.1 Strength check
　　Carry out intensity check according to formula (4).
　　　　Tc≤Tn or Tc≤Tf or TC≤Tp ……(4)
　Where:
　　Tc-calculated torque, Nm;
　　Tn- revolution torque, that is, under the given conditions-coupling speed n≈10r/min, axis bending angle β=3° and bearing life LN=5000 hours, the theoretical calculation value under stable load; Nm;
　　Tf- the allowable torque according to the fatigue strength under alternating load, Nm;
　　Tp- the allowable torque according to fatigue strength under pulsating load, Nm;
　　Tp = 1.45 Tf 
　3.2 Bearing life check The bearing life check shall be carried out according to formula (5).
　　　　　LN= KL/ K1nβTf10/3X1010≥Lmin ……(5)
　Where:
　　LN-service life, hours;
　　n- working speed, r/min;
　　β-The axis bend angle at the joint node during working, (°)
　　Tf-fatigue torque, KN.m;
　　K1- prime mover coefficient
　　Motor: K1=1
　　Diesel engine: K1=1.2;
　　KL-bearing capacity factor;
　　Lmin-The minimum life of the bearing, in hours. 
4.When the coupling has an axis angle between the horizontal and vertical planes at the same time, the composite axis angle is calculated according to formula (6):
　Where:
　　β---synthetic axis bending angle, (°);
　　β1---axis angle of the horizontal plane, (°);
　　β2---axis angle of the vertical plane, (°); 
5.In addition to the selection of universal joints based on torque and life, when the rotating diameter is less than (or equal to) 390mm, the maximum speed should also be checked according to formula (7) and formula (8).
　　　　　　nmax≤[nβ] ……(7)
　　　　　　nmax≤[nL] ……(8)
　Where:
　　nmax---Maximum working speed, r/min.