1. Stop the pumping unit crank at the 45-60 ° position on the upper right, apply the brakes firmly, hold the polished rod with a polished rod clamp, sit on the packing box, and remove the load.
2. Remove the connecting rod and crank pin bearing seat, pull out the split pin, remove the crown nut, remove the crank pin from the crank hole, clean the crank hole and apply butter.
3. Remove the bearing cover brake washer and round nut, smash out the old crank pin, install the new crank pin, tighten the nut, brake washer and bearing cover, and inject butter.
4. Put the new liner into the crank stroke hole, and then install the new tip. After installing the key, place the compression washer and the crown nut.
5. Connect the connecting rod and tighten the crown nut. The compression washer should maintain a gap of 4-10 mm from the end face of the crank hole, and install the cotter pin.
6. Loosen the brake and reel the oil pumping unit, let the donkey head hang on the load, and remove the bare rod clamp on the packing box.
7. Open the pump to check the installation quality.