1. There is a deviation during the assembly of the piston rod and packing box, which causes local mutual friction and should be adjusted in a timely manner;
2. The sealing ring holding spring is too tight and has high friction force, which should be adjusted appropriately;
3. The axial clearance of the sealing ring is too small, and the axial clearance should be adjusted according to the specified requirements;
4. When the fuel supply is insufficient, it should be increased appropriately;
5. The running in of the piston rod and sealing ring is poor, and it should be strengthened during matching research;
6. Impurities mixed in gas and oil should be clean and kept clean.
The above is the cause of overheating of the piston rod.