① The heating temperature should be properly controlled. If the temperature is too high, the bearing will be damaged, and if the temperature is too low, the expansion amount of the ring is insufficient, and the effect is not significant. The thermal expansion of the inner diameter of the inner ring obtained from the heating temperature of 80 ~ 1000℃ is enough for bearings with general interference.

②Once the required heating temperature is reached, it is necessary to install as soon as possible to avoid cooling and installation difficulties.

③The bearing also shrinks in the width direction when it is cooled, so it is necessary to apply a certain amount of pressure to tighten the inner ring to the shoulder when it is installed, and after cooling, a very thin feeler rule is used to test whether there is a gap between the inner ring end face and the shoulder. In a word, butterfly work requires skill, speed and accuracy.

(1) Decompose and clean the crankshaft assembly to ensure that the internal oil passage of the crankshaft is clean and smooth.

(2) To test the crankshaft, if there is a crack, must be replaced. Carefully inspect crankshaft journal, connecting rod journal and transition arc, all surfaces are free from scratches, burns and dents.

(3) Check the crankshaft shaft journal and connecting rod journal, and repair it according to the repair grade after the size exceeds the limit. Crankshaft journal repair will be as follows:

(4) Check the hardness requirements of crankshaft journal and connecting rod journal, which must meet the technical requirements. Otherwise, it should be reprocessed to meet use requirements.

(5) The radial circular runout of crankshaft and the radial runout of thrust facing the common axis of the main shaft journal must meet the technical requirements. Otherwise, it must be corrected.

(6) The parallelism of the common axis of the journal of the connecting rod must meet the technical requirements within the full length.

(7) The crankshaft should be replaced when the front and rear transmission gears have cracks, damage and serious wear.

(8) Crankshaft balance block bolts, if cracked, must be replaced. After the crankshaft is replaced with balance block or balance block bolt, the crankshaft assembly shall be subjected to action balance test to ensure unbalance meets technical requirements.

(9) The bolts of flywheel and belt wheel should be replaced if there are cracks, scratches or elongation exceeds the limit.

(10) carefully check the shock absorber of the crankcase support foot. If there is damage, rubber aging, cracking, deformation or crack, it must be replaced.

(11) When assembling crankshaft, pay attention to the installation of spindle tile and thrust tile. Check crankshaft axial clearance and tighten main bearing cover vertical and horizontal bolts as required.

When the bearing equipment is disassembled during regular maintenance, operation and replacement of peripheral parts, the need to judge whether the bearing parts can be used again and record the good or bad use of the situation. In order to find out and query the remaining amount of lubricant, after sampling, it is necessary to clean the bearing well.

A. Any one of the inner and outer rings, rolling bodies and face frames has cracks and fragments.

B. Any one of the inner and outer rings or rolling bodies is stripped.

C. There are significant stuck injuries on raceway surface, guard edge and rolling body.

D. stand badly worn or rivet loose ferocious.

E. Rusted and scarred raceway surface and rolling body.

F. There are significant indentation and striking marks on the rolling surface and rolling body.

G. Creep on the inner diameter surface of the inner ring or the outer diameter of the outer ring.

H. Overheated and discolored fiercely.

I. The sealing ring and dust cover of the grease sealing bearing are damaged seriously.

e-mail：bearing6@hyzcgroup.com