Cross Bearing Universal Coupling Installation, Use And Maintenance Precautions

Features and applications of Cross bearing universal couplings

Cross bearing universal coupling is a kind of general-purpose transmission basic parts, its main characteristic is that it can connect the two transmission shaft system which is not in the same axis, and can reliably transmit torque and motion.

Correct installation, reasonable use and regular maintenance of cross bearing universal couplings are important to ensure rotational performance and prolong their service life.

1) Installation Precautions

(1) In principle, both ends of the universal coupling can be used as active and driven, the installation should be in line with the design of the transmission system, as far as possible to make the spline vice far away from the source of vibration or impact source.

(2) For the universal coupling with spline vice retractable, when installing, it should be checked whether the arrow marks of the spline shaft and spline sleeve are correct, so as to ensure that the phase difference between the axes of the fork head bearing holes at both ends is not more than 10. 

2) Cleaning and inspection

(1) Before installation, it is necessary to clean the oil stains and dry the surface of the flange. The flange connecting bolts must be tightened with torque wrench according to the specified preloading torque, and the mechanical property grade of the bolts and nuts should not be lower than 10.9 grade.

(2) Before tightening the bolts, the threads shall be cleaned or washed and coated with a little glue and tightened in a staggered manner (bottom hardness washers are not allowed).

(3)After running the installed universal coupling with load for one shift (8h), the flange coupling bolts should be checked whether they are loose and tightened again according to the pre-tightening torque, and so on for several shifts until the bolts are no longer loose.

(4) Long-term overloading and unauthorized operation of the universal coupling should be avoided, otherwise the service life will be reduced.

3)Lubrication rules

(1) Brand new universal joints are adequately greased and do not require re-greasing. However, when stored for more than six months, they need to be re-greased before being put on the machine.

(2) Universal coupling lubrication should be adequate. The bearing part should be lubricated once a week at the beginning of operation, and after normal operation, grease should be added once a quarter, and grease should be added once every six months on the spline side. When replenishing the grease on the bearing, the new grease should be squeezed out from the old grease from the J-shaped oil seal until the new grease overflows.

4) Inspection Matters

Universal coupling in operation, inspection matters.

(1) Whether there is an abnormal sound;

(2) Whether there is axial runout of the cross pack;

(3) Whether the radial runout is normal;

(4) whether the coupling bolt is loose.

If any of these phenomena occur, they should be examined, analysed for reasons, and repaired.

5) Maintenance period

Normal operation of the universal coupling, the maintenance period is generally in half a year to a year, maintenance should check the items are:

Cross bearing journal, bearing outer ring and short cylindrical roller between the contact surface wear, measure its radial clearance, and observe the contact surface whether there are indentation, pitting, spalling, cracks and other phenomena. If the above phenomenon exists then repair or replace.

(2) Whether the spline vice sliding flexible, when the spline tooth wear or fit clearance is too large and distortion deformation, should be replaced or repaired.

(3) Since the universal coupling of roller press is a high-speed running equipment, it is necessary to carry out the balance test if necessary.

3 Safety Protection Measures

The broken connecting bolts of the universal joint and the damage of the Cross bearing may cause the universal joint parts to be thrown out of the accident, and there is a great potential danger, so it is recommended to optimize and improve the design of the universal joint protective cover appropriately.